bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial Distribution Characteristics and Driving Factors of Rural Revitalization Model Villages in the Yangtze River Delta
Authors: Yang Jin , Xu Chen , Fang Zhiyong , Shi Yuanbo
Published: October 2022

The scientific promotion of rural revitalization is an important issue in the context of global poverty reduction and sustainable development. For China, the largest developing country in the world, the construction of rural revitalization model villages has become an important measure to achieve agricultural and rural modernization and the coordinated development of urban and rural areas. Research on the rural revitalization model villages in China can provide guidance for the rural transformation development in other developing countries. In this paper, the Yangtze River Delta (YRD) was used as the study area, and the spatial differentiation characteristics and driving factors of 1621 rural revitalization model villages were analyzed using ArcGIS software and the geographical detector method. The results are as follows: (1) The multiscale spatial distributions of rural revitalization model villages in the YRD showed a weak agglomeration and disequilibrium characteristic. Anhui Province has the highest imbalanced distribution of model villages among different provinces in the YRD. (2) The model villages are the most densely distributed along the Yangtze River. Extending to the north and south from areas along the Yangtze River, the distribution of the model villages is first sparse then dense. Model villages agglomerate mainly along rivers and lakes, areas close to traffic arteries and the middle areas of suburban. (3) The spatial differentiation of rural revitalization model villages is the result of the combined effect of multiple factors, and the driving factors also showed significant spatial heterogeneity. The most important driving factors of the spatial differentiation of the model villages of the YRD, Jiangsu, Zhejiang, and Anhui are social development and government intervention, transportation accessibility and economic development, resource endowment and natural conditions, and transportation accessibility and government intervention, respectively. This study has practical significance for optimizing the spatial pattern of rural revitalization model villages in the YRD and facilitating high-quality rural revitalization.
Archaeomagnetic Dating of Three Furnaces inside the Middle Age Settlement of San Genesio (San Miniato, Pisa, Italy)
Authors: Principe Claudia , Goguitchaichvili Avto , Devidze Marina , La Felice Sonia , Cejudo Ruben , Morales Juan , Cantini Federico
Published: October 2022

Archaeomagnetic dating using full geomagnetic vector was performed on three furnaces cropping out at San Genesio archaeological zone, an ancient settlement located in the Arno River plain, near San Miniato (Pisa). The first evidence of human presence in this area dates back to the period between the VI century BCE and 1248 CE, when the village of San Genesio was destroyed by the inhabitants of the nearby castle of San Miniato. Three burned structures were located at different stratigraphic levels. The SGEN01 represents a kiln to produce pottery. The SGEN02 is probably a furnace for domestic use, while the SGEN03 is interpreted as a metallurgic kiln due to the presence of some hematite fragments possibly coming from Elba Island. Both mean paleodirections and absolute intensity were compared with the global geomagnetic model SCHA.DIF4K (Pavón-Carrasco et al., 2021) for Europe. The obtained age intervals at the 65% probability are 846-911 CE for SGEN01, 696-799 CE for SGEN02, and 623-644 CE for SGEN03. These new absolute dates agree well with their archaeological/stratigraphic position and with the history of the archaeological place.
Chatting with Your Peers across Modalities: Effects of Performing Increasingly Complex Written Computer-Mediated Tasks on Oral L2 Development
Authors: Korvesi Evgenia , Michel Marije
Published: October 2022

This study investigates whether peer interaction in a second language (L2) using written computer-mediated communication (CMC or text chat) may function as a bridge into oral performance. By designing and sequencing tasks according to the SSARC model of task complexity (we also examine its effects on L2 development. Finally, we explore the role of learners’ affective variables for L2 performance and development. Fifteen low–intermediate adolescent refugee learners of L2 English in the Netherlands participated in the study. Using a within-subject pre-test post-test design, we examined their language performance in both text-based CMC and face-to-face (F2F) tasks before and after a task-based classroom intervention. Results show that the intervention had a significant and strong effect on most of the linguistic measures of complexity, accuracy, and fluency (CAF). Similar gains in text chat and oral interaction provide evidence that a direct transfer of language experiences across modalities can occur. Together with the fact that most participants valued the use of written CMC in the classroom, our findings indicate that increasingly complex text chat tasks can be an effective way to promote the oral skills of language learners. We discuss our findings in light of how the design of written CMC tasks can afford L2 development across modalities.
The Enigmatic Etiology of Oculo-Auriculo-Vertebral Spectrum (OAVS): An Exploratory Gene Variant Interaction Approach in Candidate Genes
Authors: Estandia-Ortega Bernardette , Reyna-Fabián Miriam Erandi , Velázquez-Aragón José Antonio , González-del Angel Ariadna , Fernández-Hernández Liliana , Alcántara-Ortigoza Miguel Angel
Published: October 2022

The clinical diagnosis of oculo-auriculo-vertebral spectrum (OAVS) is established when microtia is present in association with hemifacial hypoplasia (HH) and/or ocular, vertebral, and/or renal malformations. Genetic and non-genetic factors have been associated with microtia/OAVS. Although the etiology remains unknown in most patients, some cases may have an autosomal dominant, autosomal recessive, or multifactorial inheritance. Among the possible genetic factors, gene–gene interactions may play important roles in the etiology of complex diseases, but the literature lacks related reports in OAVS patients. Therefore, we performed a gene–variant interaction analysis within five microtia/OAVS candidate genes (HOXA2, TCOF1, SALL1, EYA1 and TBX1) in 49 unrelated OAVS Mexican patients (25 familial and 24 sporadic cases). A statistically significant intergenic interaction (p-value < 0.001) was identified between variants p.(Pro1099Arg) TCOF1 (rs1136103) and p.(Leu858=) SALL1 (rs1965024). This intergenic interaction may suggest that the products of these genes could participate in pathways related to craniofacial alterations, such as the retinoic acid (RA) pathway. The absence of clearly pathogenic variants in any of the analyzed genes does not support a monogenic etiology for microtia/OAVS involving these genes in our patients. Our findings could suggest that in addition to high-throughput genomic approaches, future gene–gene interaction analyses could contribute to improving our understanding of the etiology of microtia/OAVS.
Rethinking Chronic Kidney Disease in the Aging Population
Authors: Alfano Gaetano , Perrone Rossella , Fontana Francesco , Ligabue Giulia , Giovanella Silvia , Ferrari Annachiara , Gregorini Mariacristina , Cappelli Gianni , Magistroni Riccardo , Donati Gabriele
Published: October 2022

The process of aging population will inevitably increase age-related comorbidities including chronic kidney disease (CKD). In light of this demographic transition, the lack of an age-adjusted CKD classification may enormously increase the number of new diagnoses of CKD in old subjects with an indolent decline in kidney function. Overdiagnosis of CKD will inevitably lead to important clinical consequences and pronounced negative effects on the health-related quality of life of these patients. Based on these data, an appropriate workup for the diagnosis of CKD is critical in reducing the burden of CKD worldwide. Optimal management of CKD should be based on prevention and reduction of risk factors associated with kidney injury. Once the diagnosis of CKD has been made, an appropriate staging of kidney disease and timely prescriptions of promising nephroprotective drugs (e.g., RAAS, SGLT-2 inhibitors, finerenone) appear crucial to slow down the progression toward end-stage kidney disease (ESKD). The management of elderly, comorbid and frail patients also opens new questions on the appropriate renal replacement therapy for this subset of the population. The non-dialytic management of CKD in old subjects with short life expectancy features as a valid option in patient-centered care programs. Considering the multiple implications of CKD for global public health, this review examines the prevalence, diagnosis and principles of treatment of kidney disease in the aging population.
Quality of Life Impact of Hypoglossal Nerve Stimulation with Inspire® Device in Patients with Obstructive Sleep Apnea Intolerant to Continuous Positive Airway Pressure Therapy
Authors: Baptista Peter , Di Frisco I. Madeleine , Urrestarazu Elena , Alcalde Juan , Alegre Manuel , Sanchez Isabel , O’Connor-Reina Carlos , Plaza Guillermo
Published: October 2022

Patients with obstructive sleep apnea (OSA) that do not tolerate/accept continuous positive airway pressure (CPAP) are candidates for surgical alternatives. Hypoglossal nerve stimulation (HNS) through the implantation of the Inspire® device constitutes a minimally invasive operative option. The main objective of this study is to estimate, under real-world clinical practice conditions, the 3-month impact on the quality of life (IQoL) of the HNS in patients with moderate/severe OSA who do not tolerate or accept CPAP, compared to patients who did not receive HNS. As a baseline, the unadjusted EuroQol utility index was 0.764 (SD:0.190) in the intervention group (IGr) and 0.733 (SD:0.205) in the control group (CGr); three months later, the indexes were 0.935 (SD: 0.101) and 0.727 (SD:0.200), respectively. The positive impact on quality of life was estimated to be +0.177 (95% CI: 0.044–0.310; p = 0.010). All dimensions in the IGr improved compared to CGr, especially for usual activities (p < 0.001) and anxiety/depression (p > 0.001). At the end of the follow-up, there was no significant difference in the quality of life between the general Spanish population and the IGr (difference: 0.012; CI95%: −0.03 to −0.057; p = 0.0578) for the same age range; however, there was a difference concerning the CGr (difference: −0.196; CI95%: −0.257 to −0.135; p < 0.001). In conclusion, patients with moderate/severe OSA implanted with the Inspire® device showed a positive IQoL.
Medium-Term Effect of Treatment with Intra-Articular Injection of Sodium Hyaluronate, Betamethasone and Platelet-Rich Plasma in Patients with Temporomandibular Arthralgia: A Retrospective Cohort Study
Authors: Macedo de Sousa Bruno , López-Valverde Antonio , Caramelo Francisco , Rodrigues María João , López-Valverde Nansi
Published: October 2022

Temporomandibular joint disorders are associated with pain and reduced jaw mobility. The aim of this study was to compare the long-term effect on pain of intra-articular TMJ injections of betamethasone, sodium hyaluronate and platelet-rich plasma. The sample was made up of 114 patients, who were randomly distributed into three groups at least three years ago and who achieved a total remission of pain after treatment. We found that the median number of months without pain was, according to each group, as follows: platelet-rich plasma: 33; sodium hyaluronate: 28; betamethasone: 19. Both platelet-rich plasma and sodium hyaluronate lead to significant pain-free time after treatment; when we compare bethametasone with the two other substances, it proved to be very ineffective.
Combined Therapy of Probiotic Microcapsules and Bomidin in Vibrio parahaemolyticus–Infected Rats
Authors: Zhou Ting , Liu Mengting , Pan Jialiang , Ren Jianluan , Tang Fang , Dai Jianjun , Xue Feng , Ji Dejun
Published: October 2022

Background: With the discovery of more and more drug–resistant bacterial strains, there is an urgent need for safer and more effective alternative treatments. In this study, antibacterial peptides and probiotic microcapsules were combined to treat gastrointestinal inflammation caused by Vibrio parahaemolyticus infection. Methods: To improve the stability of probiotics in the gastrointestinal tract, two types of mixed natural anionic polysaccharides and chitosan were used as carriers to embed the probiotics. Taking Lacticaseibacillus casei CGMCC1.8727 microcapsules with good performance as the research object, the in vitro characteristics of the microcapsules were studied via acid resistance test and intestinal release test. The microcapsules were then tested for in vivo treatment in combination with the antibacterial peptide, bomidin, and the therapeutic effects were compared among microencapsulated probiotics, free probiotics, and probiotics in combination with bomidin. Results: Microencapsulation was successfully manufactured under suitable processing parameters, with the product particle size being 2.04 ± 0.2743 mm. Compared with free probiotics, microencapsulation significantly improved the activity and preservation stability of the probiotics under simulated gastrointestinal conditions. Microencapsulated probiotics showed better therapeutic effects than free probiotics in vivo. Microcapsules combined with antimicrobial peptides accelerated the elimination of bacteria in vivo. This study provides a reference for anti–inflammatory treatment, especially for the treatment of gastrointestinal diseases.
Inferring Therapeutic Targets in Candida albicans and Possible Inhibition through Natural Products: A Binding and Physiological Based Pharmacokinetics Snapshot
Authors: Basharat Zarrin , Khan Kanwal , Jalal Khurshid , Alnasser Sulaiman Mohammed , Majeed Sania , Zehra Marium
Published: October 2022

Despite being responsible for invasive infections, fungal pathogens have been underrepresented in computer aided therapeutic target mining and drug design. Excess of Candida albicans causes candidiasis, causative of thrush and vaginal infection due to off-balance. In this study, we attempted to mine drug targets (n = 46) using a subtractive proteomic approach in this pathogenic yeast and screen natural products with inhibition potential against fructose-bisphosphate aldolase (FBA) of the C. albicans. The top compound selected on the basis of best docking score from traditional Indian medicine/Ayurvedic library was (4-Hydroxybenzyl)thiocarbamic acid, from the ZINC FBA inhibitor library was ZINC13507461 (IUPAC name: [(2R)-2-hydroxy-3-phosphonooxypropyl] (9E,12E)-octadeca-9,12-dienoate), and from traditional Tibetan medicine/Sowa rigpa was Chelerythrine (IUPAC name: 1,2-Dimethoxy-12-methyl-9H-[1,3]benzodioxolo[5,6-c]phenanthridin-12-ium), compared to the control (2E)-1-(4-nitrophenyl)-2-[(4-nitrophenyl)methylidene]hydrazine. No Ames toxicity was predicted for prioritized compounds while control depicted this toxicity. (4-Hydroxybenzyl)thiocarbamic acid showed hepatotoxicity, while Chelerythrine depicted hERG inhibition, which can lead to QT syndrome, so we recommend ZINC13507461 for further testing in lab. Pharmacological based pharmacokinetic modeling revealed that it has low bioavailability and hence, absorption in healthy state. In cirrhosis and renal impairment, absorption and plasma accumulation increased so we recommend further investigation into this occurrence and recommend high dosage in further tests to increase bioavailability.
Sepsityper® Kit versus In-House Method in Rapid Identification of Bacteria from Positive Blood Cultures by MALDI-TOF Mass Spectrometry
Authors: Perše Gabrijela , Samošćanec Ivana , Bošnjak Zrinka , Budimir Ana , Kuliš Tomislav , Mareković Ivana
Published: October 2022

In order to further accelerate pathogen identification from positive blood cultures (BC), various sample preparation protocols to identify bacteria with MALDI-TOF MS directly from positive BCs have been developed. We evaluated an in-house method in comparison to the Sepsityper® Kit (Bruker Daltonics, Bremen, Germany) as well as the benefit of an on-plate formic acid extraction step following positive signal by the BACTECTM FX system. Confirmation of identification was achieved using subcultured growing biomass used for MALDI-TOF MS analysis. A total of 113 monomicrobial positive BCs were analyzed. The rates of Gram-positive bacteria correctly identified to the genus level using in-house method and Sepsityper® Kit were 63.3% (38/60) and 81.7% (49/60), respectively (p = 0.025). Identification rates at species level for Gram-positive bacteria with in-house method and Sepsityper® kit were 30.0% (18/60) and 66.7% (40/60), respectively (p < 0.001). Identification rates of Gram-negative bacteria were similar with the in-house method and Sepsityper® Kit. Additional on-plate formic acid extraction demonstrated significant improvement in the identification rate of Gram-positive bacteria at both genus and species level for both in-house (p = 0.001, p < 0.001) and Sepsityper® Kit methods (p = 0.007, p < 0.001). Our in-house method is a candidate for laboratory routines with Sepsityper® Kit as a back-up solution when identification of Gram-positive bacteria is unsuccessful.
Study on the Performance and Corrosion Failure Process of Porous Titanium-Based Coated Electrodes
Authors: Li Jiamin , Chang Linhui , Chen Buming , Huang Hui , Guo Zhongcheng
Published: October 2022

Titanium-based coated electrodes are considered to be a substitute for Pb-based anodes because of their lower weights and lower energy consumption; however, their properties and service lives are affected by the matrix structure. Herein, the metal oxide coating was prepared via the thermal oxidation decomposition of a 5 μm-porous titanium plate. The scanning electron microscope (SEM) showed that the metal oxide coating on the porous titanium plate was strengthened in each layer that had pores. The inner coating of the particles are sized using nanometers, with a diameter of 22–64 nm and a compact structure. The electrochemical test results show that, compared with the flat titanium plate, the coating attached to the porous titanium plate has a better catalytic performance in the chlorine evolution reaction, (the chlorine evolution potential decreases by 121 mV), and the service life is increased by 3.78 times. Through a SEM, XRD, and EDS analysis of the coating composition after corrosion failure, the corrosion mechanism of the surface oxide coating was discussed.
Analysis of Tribological Properties of Powdered Tool Steels M390 and M398 in Contact with Al2O3
Authors: Studeny Zbynek , Krbata Michal , Dobrocky David , Eckert Maros , Ciger Robert , Kohutiar Marcel , Mikus Pavol
Published: October 2022

The present article examines special steels used for the production of injection screws in the plastic industry, with a glass fiber content of up to 30%. Experimental materials, M390 and M398, are classified as tool steels, which are produced by powder metallurgy-HIP methods (hot isostatic pressing). The main goal of the presented paper is to propose the optimal tempered temperature of M398 steel and also to compare the tribological properties of both materials and to determine the degree of their wear depending on their final heat treatment. Partial results refer to the analysis of hardness, roughness, the overall wear mechanism, the change in the volume of retained austenite due to the tempering temperature, and the EDS analysis of the worn surfaces in individual contact pairs. A ceramic ball Al2O3 in the α phase was used as the contact material, which had a diameter of 6.35 mm. The ceramic ball performed a rotational movement on the experimental material surface at an elevated temperature of 200 °C using the dry ball-on-disk method. It was experimentally shown that the new M398 material can fully replace the M390 material because it exhibits significantly better tribological properties. The M398 material showed more than a 400% reduction in wear compared to the M390 material. The ideal heat treatment consisted of cryogenic quenching to −78 °C and a tempering temperature of 400 °C. At tempering temperatures of 200 and 400 °C, adhesive wear occurred, which was combined with abrasive wear at a tempered temperature of 600 °C. The averaged coefficient of friction (COF) results show that the M398 material presents less resistance in the friction process and its values are approximately 0.25, while the M390 material showed a COF value of 0.3 after the cryogenic hardening process. The friction surface roughness of the M398 materials also showed lower values compared to the M390 material by approximately 35%. Both of these results are related to the content of M7C3 and MC carbide particles based on Cr and V in the bulk of the material, which are in favor of the M398 material.
Electrical Conductivity of Additively Manufactured Copper and Silver for Electrical Winding Applications
Authors: Robinson John , Munagala Sai Priya , Arjunan Arun , Simpson Nick , Jones Ryan , Baroutaji Ahmad , Govindaraman Loganathan T. , Lyall Iain
Published: October 2022

Efficient and power-dense electrical machines are critical in driving the next generation of green energy technologies for many industries including automotive, aerospace and energy. However, one of the primary requirements to enable this is the fabrication of compact custom windings with optimised materials and geometries. Electrical machine windings rely on highly electrically conductive materials, and therefore, the Additive Manufacturing (AM) of custom copper (Cu) and silver (Ag) windings offers opportunities to simultaneously improve efficiency through optimised materials, custom geometries and topology and thermal management through integrated cooling strategies. Laser Powder Bed Fusion (L-PBF) is the most mature AM technology for metals, however, laser processing highly reflective and conductive metals such as Cu and Ag is highly challenging due to insufficient energy absorption. In this regard, this study details the 400 W L-PBF processing of high-purity Cu, Ag and Cu–Ag alloys and the resultant electrical conductivity performance. Six Cu and Ag material variants are investigated in four comparative studies characterising the influence of material composition, powder recoating, laser exposure and electropolishing. The highest density and electrical conductivity achieved was 88% and 73% IACS, respectively. To aid in the application of electrical insulation coatings, electropolishing parameters are established to improve surface roughness. Finally, proof-of-concept electrical machine coils are fabricated, highlighting the potential for 400 W L-PBF processing of Cu and Ag, extending the current state of the art.
Geopolymer Ceramic Application: A Review on Mix Design, Properties and Reinforcement Enhancement
Authors: Mohd Mortar Nurul Aida , Abdullah Mohd Mustafa Al Bakri , Abdul Razak Rafiza , Abd Rahim Shayfull Zamree , Aziz Ikmal Hakem , Nabiałek Marcin , Jaya Ramadhansyah Putra , Semenescu Augustin , Mohamed Rosnita , Ghazali Mohd Fathullah
Published: October 2022

Geopolymers have been intensively explored over the past several decades and considered as green materials and may be synthesised from natural sources and wastes. Global attention has been generated by the use of kaolin and calcined kaolin in the production of ceramics, green cement, and concrete for the construction industry and composite materials. The previous findings on ceramic geopolymer mix design and factors affecting their suitability as green ceramics are reviewed. It has been found that kaolin offers significant benefit for ceramic geopolymer applications, including excellent chemical resistance, good mechanical properties, and good thermal properties that allow it to sinter at a low temperature, 200 °C. The review showed that ceramic geopolymers can be made from kaolin with a low calcination temperature that have similar properties to those made from high calcined temperature. However, the choice of alkali activator and chemical composition should be carefully investigated, especially under normal curing conditions, 27 °C. A comprehensive review of the properties of kaolin ceramic geopolymers is also presented, including compressive strength, chemical composition, morphological, and phase analysis. This review also highlights recent findings on the range of sintering temperature in the ceramic geopolymer field which should be performed between 600 °C and 1200 °C. A brief understanding of kaolin geopolymers with a few types of reinforcement towards property enhancement were covered. To improve toughness, the role of zirconia was highlighted. The addition of zirconia between 10% and 40% in geopolymer materials promises better properties and the mechanism reaction is presented. Findings from the review should be used to identify potential strategies that could develop the performance of the kaolin ceramic geopolymers industry in the electronics industry, cement, and biomedical materials.
Effect of the Matrix Melt Flow Index and Fillers on Mechanical Properties of Polypropylene-Based Composites
Authors: Junaedi Harri , Baig Muneer , Dawood Abdulsattar , Albahkali Essam , Almajid Abdulhakim
Published: October 2022

In this work, mechanical properties of reinforced polypropylene composites were studied. PP in particulates shape with two different melt flow indexes (MFI) was used, i.e., 3 and 23 g/10 min, namely PP3 and PP23, respectively. Three different materials, namely TiO2 nanoparticle (nTiO2, spherical, 0D), micro-size short carbon fiber (SCF, fiber, 1D), and graphite nanoplatelet (GNP, sheet, 2D), were used as reinforcements/fillers. PP and fillers (in the desired composition) were first pre-mixed by a mechanical mixer. The mixture was then fed to a co-rotating twin-screw extruder for melt-compounding, followed by injection molding to fabricate testing samples. The microstructure and fracture surface of the composites were observed by a scanning electron microscope (SEM). Additionally, tensile, flexural, impact, and hardness tests were conducted to evaluate their mechanical properties. The SEM images stipulate that PP23 had better adhesion and dispersion with the fillers. The results from the SEM images support the mechanical testing results. PP23 composites exhibited more significant improvement in mechanical properties in comparison to PP3. At 5 wt. % filler loading, PP/GNP composite exhibited a greater improvement in mechanical properties compared with two other composites, which are PP/SCF and PP/nTiO2 composites for both PPs.
Utilizing Tunnel Boring Machine (TBM)-Crushed Limestone as a Construction Material
Authors: Alnuaim Ahmed , Al-Mahbashi Ahmed M. , Dafalla Muawia
Published: October 2022

Tunnel boring machine (TBM) materials are usually crushed powder obtained during tunnel excavations for subways and transportation networks. Huge quantities of crushed rock powder are generally treated as waste. This study is aimed at assessing proposed mixtures of TBM and granular material for use in construction. This approach will help in a greener environment and reduce the need for crushed aggregates used in sub-base and subgrade layers of pavements. Assessment is executed using dynamic and static strength tests, including the modulus of resilience and the California bearing ratio (CBR). The TBM-crushed material can be sorted and screened on site to optimize its use as a construction material. The blending ratios for the 3/8-inch aggregate (G1) to the material-passing sieve number 4 (P4) were found to influence the pavement design parameters. This study recommends sorting the TBM-crushed limestone by an on-site sieving operation. A guide to optimizing the quality of the material is suggested by blending 3/8-inch aggregate with the crushed limestone fine-powder material at a specified percentage ranging from 5 to 10% by weight. The stability and durability tests conducted on the TBM-crushed powder material confirmed its suitability as a pavement construction material for subgrade and sub-base layers. Modulus of resilience, CBR values and compressive strength tests were carried out for different suggested mixtures.
Development and Characterization of PBSA-Based Green Composites in 3D-Printing by Fused Deposition Modelling
Authors: Niang Babacar , Schiavone Nicola , Askanian Haroutioun , Verney Vincent , Ndiaye Diène , Diop Abdoulaye Bouya
Published: October 2022

Fused deposition modelling is a rapidly growing additive manufacturing technology due to its ability to build functional parts with complex geometries. The mechanical properties of a built part depend on several process parameters. The effect of wood content on the properties of 3D printed parts has been studied. Four types of filaments using poly(butylene succinate-co-adipate) (PBSA) with different reinforcement levels of Typha stem powder 0%, 5%, 10%, and 15% by weight were used for 3D printing. The density of the filaments and parts printed in this study increased with the Typha stem powder content. The thermal stability, mechanical performance, and viscoelastic properties of the different biocomposite filaments and 3D printed objects were analysed. The results show an increase in the crystallisation kinetics and a slight decrease in the thermal stability of the biomaterials. Compared to virgin PBSA FDM filaments, the PBSA biocomposite filament filled with Typha stem powder showed an increase in the tensile strength of the parts and specimens from 2.5 MPa to 8 MPa and in the modulus of elasticity from 160 MPa to 375 MPa, respectively, with additions of 5%, 10%, and 15% by mass. The addition of Typha stem fibres generated an increase in the elastic behaviour and relaxation time of the biomaterial structure, visualised by increases in the values of the viscosity components. The surface morphology reveals a decrease in the porosity of the printed samples.
A Review of Lightweight Self-Healing Concrete
Authors: Huang Feng , Zhou Shuai
Published: October 2022

Cementitious composites often crack because of their low tensile strength. The ability of self-healing cementitious composite to automatically repair cracks has attracted widespread attention. Lightweight aggregate (LWA) has a low density and a high porosity which can provide storage space for a healing agent. The healing mechanisms and healing compositions of lightweight self-healing concrete (LWSHC) have been summarized in this research. The workability, compressive strength, crack repairing, and durability of LWSHC performance is also illustrated. A LWA with interconnected pores and a high strength should be integrated into LWSHC to increase the crack closure rate and mechanical properties. Expanded perlite is the most suitable LWA carrier for bioremediation. The chemical healing agents are better than the biological healing agents at present since the biological healing agents have more negative effects. A sodium silicate solution is a good choice as a chemical healing agent. Vacuum conditions, high-temperature processing, and the use of coating technologies on LWAs can improve the healing effect of LWSHC. The addition of fibers also enhance the self-healing ability of LWSHC. Further, the use of numerical simulation supports the healing performance of LWSHC. The goal of this research is to investigate the most appropriate component of LWSHC to ensure a high crack closure rate, strength healing ratio, and great durability while being lightweight. It can then be adopted in high-rise and large-span concrete structures to extend the service life.
A Comparative Density Functional Theory Study of Hydrogen Storage in Cellulose and Chitosan Functionalized by Transition Metals (Ti, Mg, and Nb)
Authors: Faye Omar , Szpunar Jerzy A. , Eduok Ubong
Published: October 2022

The focus of this work is hydrogen storage in pristine cellulose, chitosan, and cellulose. Chitosan doped with magnesium, titanium, and niobium is analyzed using spin unrestricted plane-wave density functional theory implemented in the Dmol3 module. The results of this study demonstrate that hydrogen interaction with pure cellulose and chitosan occurred in the gas phase, with an adsorption energy of Eb = 0.095 eV and 0.090 eV for cellulose and chitosan, respectively. Additionally, their chemical stability was determined as Eb= 4.63 eV and Eb = 4.720 eV for pure cellulose and chitosan, respectively, by evaluating their band gap. Furthermore, the presence of magnesium, titanium, and niobium on cellulose and chitosan implied the transfer of an electron from metal to cellulose and chitosan. Moreover, our calculations predict that cellulose doped with niobium is the most favorable medium where 6H2 molecules are stored compared with molecules stored in niobium-doped chitosan with Tmax = 818 K to release all H2 molecules. Furthermore, our findings showed that titanium-doped cellulose has a storage capacity of five H2 molecules, compared to a storage capacity of four H2 molecules in titanium-doped chitosan. However, magnesium-doped cellulose and chitosan have insufficient hydrogen storage capacity, with only two H2 molecules physisorbed in the gas phase. These results suggest that niobium-doped cellulose and chitosan may play a crucial role in the search for efficient and inexpensive hydrogen storage media.
Study of the Effect of the Use of Asphalt Binders Modified with Polymer Fibres from End-of-Life Tyres (ELT) on the Mechanical Properties of Hot Mix Asphalt at Different Operating Temperatures
Authors: Calabi-Floody Alejandra , Mignolet-Garrido Cristian , Valdes-Vidal Gonzalo
Published: October 2022

Processing of end-of-life tyres (ELT) produces polymer fibres (PFELT) as a by-product. PFELT currently presents a challenge to the recycling industry, due to the increasing numbers of ELT and lack of alternatives for the re-use of this material. The object of this investigation was to propose an alternative for re-using PFELT, in order to improve the performance properties of hot mix asphalt (HMA). This study enabled us to understand the relation between the addition of polymer fibre to the aggregate-binder matrix of the HMA in depth, as well as its effects on the mechanical properties of the resulting asphalt mix. To do this, we first made a physical and chemical characterization of the PFELT (TGA, SEM, polarized light, and fluorescence microscopy), establishing a modification methodology using two asphalt binders (CA-24 and CA-14) and three PFELT contents (0.1%, 0.3%, and 0.5%). The HMA was designed using the Marshall method. The mechanical performance of the HMA was evaluated in a range of operating temperatures, from −10 °C to 50 °C, observing the following properties: (1) resistance to thermal cracking; (2) stiffness modulus; (3) indirect tensile strength; and (4) resistance to permanent deformation. The results show that the addition of 0.3% and 0.5% of PFELT to the asphalt binder significantly improved the mechanical performance properties of the mixes studied, with a greater effect at high operating temperatures; the resistance to permanent deformation increased by more than 30%.
Plasma-Assisted Synthesis of Surfactant-Free and D-Fructose-Coated Gold Nanoparticles for Multiple Applications
Authors: Yasin Hafiz M. , Ahmed W. , Rehman N. U. , Majd Abdul , Alkhedher Mohammad , Tag El Din ElSayed M.
Published: October 2022

The excellent optical properties of gold nanoparticles (AuNPs) make them promising for numerous applications. Herein, we present a facile synthesis of both surfactant-free (SF−AuNPs) and non-toxic D-fructose (DF)-coated gold nanoparticles (DF−AuNPs) via the plasma–liquid interactions (PLIs) method. Moreover, we demonstrate that both SF−AuNPs and DF−AuNPs are potential candidates for trace detection via surface-enhanced Raman scattering (SERS) and catalytic degradation of toxic dyes. However, SF−AuNPs have superior SERS and catalytic performance compared to the DF−AuNPs due to their surfactant-free nature. Moreover, SF−AuNPs have also been shown to quench the fluorescence of analyte molecules, making their SERS-based trace detection more efficient. In particular, SERS enhancement of rhodamine 6G (R6G) and catalytic reduction of a toxic dye methylene blue (MB) have been explored.
The First Examples of [3+2] Cycloadditions with the Participation of (E)-3,3,3-Tribromo-1-Nitroprop-1-Ene
Authors: Zawadzińska Karolina , Gadocha Zuzanna , Pabian Kamila , Wróblewska Aneta , Wielgus Ewelina , Jasiński Radomir
Published: October 2022

The first examples of [3+2] cycloaddition reactions between 3,3,3-tribromo-1-nitroprop-1-ene (TBMN) were explored on the basis of experimental and theoretical approaches. It was found that reactions involving TBMN and diarylnitrones realized with full regio- and stereoselectivity lead to respective 3,4-cis-4,5-trans-4-nitroisoxazolidines. The regioselecticity and the molecular mechanism of title processes was analyzed on the basis of the advanced DFT computational study.
Thermal Conductance of Copper–Graphene Interface: A Molecular Simulation
Authors: Zhu Jiarui , Huang Shuhui , Xie Zhongnan , Guo Hong , Yang Hui
Published: October 2022

Copper is often used as a heat-dissipating material due to its high thermal conductivity. In order to improve its heat dissipation performance, one of the feasible methods is to compound copper with appropriate reinforcing phases. With excellent thermal properties, graphene has become an ideal reinforcing phase and displays great application prospects in metal matrix composites. However, systematic theoretical research is lacking on the thermal conductivity of the copper–graphene interface and associated affecting factors. Molecular dynamics simulation was used to simulate the interfacial thermal conductivity of copper/graphene composites, and the effects of graphene layer number, atomic structure, matrix length, and graphene vacancy rate on thermal boundary conductance (TBC) were investigated. The results show that TBC decreases with an increase in graphene layers and converges when the number of graphene layers is above five. The atomic structure of the copper matrix affects the TBC, which achieves the highest value with the (011) plane at the interface. The length of the copper matrix has little effect on the TBC. As the vacancy rate is between 0 and 4%, TBC increases with the vacancy rate. Our results present insights for future thermal management optimization based on copper matrix composites.
A Chemical Damage Creep Model of Rock Considering the Influence of Triaxial Stress
Authors: Chen Youliang , Chen Qijian , Pan Yungui , Xiao Peng , Du Xi , Wang Suran , Zhang Ning , Wu Xiaojian
Published: October 2022

In order to accurately describe the characteristics of each stage of rock creep behavior under the combined action of acid environment and true triaxial stress, based on damage mechanics, chemical damage is connected with elastic modulus; thus, the damage relations considering creep stress damage and chemical damage are obtained. The elastic body, nonlinear Kelvin body, linear Kelvin body, and viscoelastic–plastic body (Mogi–Coulomb) are connected in series, and the actual situation under the action of true triaxial stress is considered at the same time. Therefore, a damage creep constitutive model considering the coupling of rock acid corrosion and true triaxial stress is established. The parameters of the deduced model are identified and verified with the existing experimental research results. The yield surface equation of rock under true triaxial stress is obtained by data fitting, and the influence of intermediate principal stress on the creep model is discussed. The derived constitutive model can accurately describe the characteristics of each stage of true triaxial creep behavior of rock under acid environment.
An Easily Used Phenomenological Magnetization Model and Its Empirical Expressions Based on Jiles–Atherton Parameters
Authors: Xue Guangming , Bai Hongbai , Li Tuo , Lu Chunhong
Published: October 2022

In this paper, a simple magnetization model convenient for engineering applications is presented based on the expressions of the first-order LTI system model. Considering the trade-off between the nonlinearity of anhysteretic magnetization and the hysteresis width, the proposed model employs two different equations with different magnetic field amplitudes. Furthermore, the proposed model utilizes the first-order LTI system model with a low magnetic field amplitude and a simple nonlinear function, based on the amplitude–frequency function, with a high magnetic field amplitude. Two important characteristic parameters for engineering applications, namely, amplitude and the equivalent phase lag, were exacted and analyzed to validate the computation precision of the proposed model. Then, the model was verified through comparisons to the validated Jiles–Atherton model. For easy use, similar to a physics-based model instead of a fitting method, empirical expressions for the model parameters were given, and applicable ranges of these equations were determined using the parameters of the Jiles–Atherton model. Finally, an example of the magnetization model applied to an on/off type device was computed to further verify the effectiveness of the proposed model with quite a simple expression.
An Investigation of Non-Linear Strength Characteristics of Solidified Saline Soils in Cold Regions
Authors: Ding Qian , Hu Zheng , Huang Shuai , Chen Kezheng , Liu Yanjie , Ding Lin
Published: October 2022

To date, the modelling of constitutive equations of solidified frozen saline soil have seldom been studied. This paper presented the formulation of a damage constitutive model for solidified saline frozen soil considering both freeze thaw cycles (FTCs) and salinities. To model the solidified frozen saline soil, the unconfined compression strength test (UCST) and consolidated undrained (CU) triaxial shear test were conducted under three ambient temperatures (20, –10, and –20 °C), five ages (3, 7, 14, 28, and 90 d), six salinities (0, 1, 2, 3, 4, and 5%), and four FTCs (0, 5, 10, and 14 times) in this research. The UCST results showed that the unconfined compressive strength (UCS) of the solidified saline soils at an age of 14 days can reach 75% of the maximum UCS, which basically meets the engineering construction requirements. The range of the rate of strength loss as affected by salinity was 16.2% to 75.65%, while the coupling effect of salt and frozen conditions amplified the rate of strength loss. Affected by increasing salinity, the rate of strength loss of frozen soils was magnified by a factor of 1.2 to 3.7 compared to thawing soils. Likewise, the CU triaxial shear test showed that the rate of strength loss of shear strength was amplified by the coupling effect of FTCs and salt erosion. With increased FTCs, the strain threshold of Young’s modulus was gradually pushed backward, which was similar to the effect of salinity. Remarkably, the damage constitutive model performed better than conventional constitutive models for the solidified saline soil under the salt–freezing coupling effect.
Biocompatible Properties and Mineralization Potential of Premixed Calcium Silicate-Based Cements and Fast-Set Calcium Silicate-Based Cements on Human Bone Marrow-Derived Mesenchymal Stem Cells
Authors: Kim Yemi , Lee Donghee , Kye Minjoo , Ha Yun-Jae , Kim Sin-Young
Published: October 2022

Premixed calcium silicate-based cements (CSCs) and fast-set CSCs were developed for the convenience of retrograde filling during endodontic microsurgery. The aim of this study was to analyze the biocompatible properties and mineralization potential of premixed CSCs, such as Endocem MTA Premixed (EM Premixed) and EndoSequence BC RRM putty (EndoSequence), and fast-set RetroMTA on human bone marrow-derived mesenchymal stem cells (BMSCs) compared to ProRoot MTA. Using CCK-8, a significantly higher proliferation of BMSCs occurred only in the EM Premixed group on days 2 and 4 (p < 0.05). On day 6, the ProRoot MTA group had significantly higher cell proliferation than the control group (p < 0.05). Regardless of the experimental materials, all groups had complete cell migration by day 4. Alizarin Red-S staining and alkaline phosphatase assay demonstrated higher mineralization potential of all CSCs similar to ProRoot MTA (p < 0.05). The EndoSequence group showed more upregulation of SMAD1 and OSX gene expression than the other experimental groups (p < 0.05), and all experimental cements upregulated osteogenic gene expression more than the control group (p < 0.05). Therefore, using premixed CSCs and fast-set CSCs as retrograde filling cements may facilitate satisfactory biological responses and comparable osteogenic potential to ProRoot MTA.
Entomopathogenic Fungi-Mediated AgNPs: Synthesis and Insecticidal Effect against Plutella xylostella (Lepidoptera: Plutellidae)
Authors: Santos Tárcio S. , de Souza Varize Camila , Sanchez-Lopez Elena , Jain Sona A. , Souto Eliana B. , Severino Patrícia , Mendonça Marcelo da Costa
Published: October 2022

The insect Plutella xylostella is known worldwide to cause severe damage to brassica plantations because of its resistance against several groups of chemicals and pesticides. Efforts have been conducted to overcome the barrier of P. xylostella genetic resistance. Because of their easy production and effective insecticidal activity against different insect orders, silver nanoparticles are proposed as an alternative for agricultural pest control. The use of entomopathogenic fungi for nanoparticle production may offer additional advantages since fungal biomolecules may synergistically improve the nanoparticle’s effectiveness. The present study aimed to synthesize silver nanoparticles using aqueous extracts of Beauveria bassiana, Metarhizium anisopliae, and Isaria fumosorosea isolates and to evaluate their insecticidal activity against P. xylostella, as innovative nano-ecofriendly pest control. The produced silver nanoparticles were evaluated by measuring the UV–vis spectrum and the mean particle size by dynamic light scattering (DLS). I. fumosorosea aqueous extract with 3-mM silver nitrate solution showed the most promising results (86-nm mean diameter and 0.37 of polydispersity). Scanning electron microscopy showed spherical nanoparticles and Fourier-Transform Infrared Spectroscopy revealed the presence of amine and amide groups, possibly responsible for nanoparticles’ reduction and stabilization. The CL50 value of 0.691 mg mL−1 was determined at 72-h for the second-instar larvae of the P. xylostella, promoting a 78% of cumulative mortality rate after the entire larval stage. From our results, the synthesis of silver nanoparticles mediated by entomopathogenic fungi was successful in obtaining an efficient product for insect pest control. The I. fumosorosea was the most suitable isolate for the synthesis of silver nanoparticles contributing to the development of a green nanoproduct and the potential control of P. xylostella.
Metal-Semiconductor AsSb-Al0.6Ga0.4As0.97Sb0.03 Metamaterial
Authors: Bert Nikolay , Ushanov Vitaliy , Snigirev Leonid , Kirilenko Demid , Ulin Vladimir , Yagovkina Maria , Preobrazhenskii Valeriy , Putyato Mikhail , Semyagin Boris , Kasatkin Igor , Chaldyshev Vladimir
Published: October 2022

AlGaAsSb and AlGaAs films as thick as 1 μm with Al content as high as 60% were successfully grown by low-temperature (200 °C) MBE. To overcome the well-known problem of growth disruption due to a high aluminum content and a low growth temperature, we applied intermittent growth with the temperature elevation to smooth out the emerging roughness of the growth front. Post-growth annealing of the obtained material allowed us to form a developed system of As or AsSb nanoinclusions, which occupy 0.3–0.6% of the material volume. While the As nanoinclusions are optically inactive, the AsSb nanoinclusions provide a strong optical absorption near the band edge of the semiconductor matrix due to the Fröhlich plasmon resonance. Owing to the wider bandgap of the grown Al0.6Ga0.4As0.97Sb0.03 compound, we have expanded the spectral range available for studying the Fröhlich plasmon resonance. The grown metamaterial represents an optically active medium of which the formation process is completely compatible with the epitaxial growth technology of semiconductors.