bluuebunny/crossref_metadata_2025 huggingface dataset:
Unraveling the Dynamics of Lifelong Learning in Singapore: A Comparative Study
Authors: Lim Zhi Yong , Lai Joel Weijia , Yap Jun Hong , Mishra Ankit , Mokhtar Intan Azura , Yeo Darren J. , Cheong Kang Hao
Published: August 2023

Lifelong learning is crucial for equipping the workforce to navigate a volatile, uncertain, complex, and ambiguous (VUCA) world. Despite its importance, resistance to enrolling in lifelong learning courses persists. This exploratory study examines the exposure to and engagement with government-sponsored courses among two distinct groups: individuals who opt for these courses and those who select alternative courses. We employed comparative statistical analysis to identify the primary factors influencing course awareness and selection. Our findings underscore the enduring influence of traditional media in promoting course awareness. Additionally, personal interest and availability of subsidies emerged as significant determinants of course selection. Based on these insights, we propose policy recommendations to enhance the effectiveness of these courses. This empirical study contributes to the understanding of the dynamics of lifelong learning in Singapore, providing valuable insights for policy and practice.
Improving the Chemical Properties of Acid Sulphate Soils from the Casamance River Basin
Authors: Bautista Inmaculada , Oliver Joana , Lidón Antonio , Osca Jose María , Sanjuán Neus
Published: August 2023

The anoxic conditions produced after the reflooding of acid sulphate soil (ASS) can reduce sulphate and/or Fe(III) with a consequent rise in pH. This study aimed to compare the effect of different amendments on ASS remediation and to analyse the effect on soil pH and exchangeable aluminium. Two mid-term incubation experiments were carried out to analyse the effect of amendments and water management on ASS. Soil samples were taken in the Santak Valley from four agricultural plots. During the first experiment, each soil sample was subject to two water management systems (flooded and non-flooded) and three amendment types (rice straw, manure, and lime). During the second experiment, the flooded condition was performed with three organic amendments (rice straw, manure, and biochar). In the first experiment, the amendments with organic matter (rice straw, and manure) increased the pH more under the flooded conditions, and manure was effective in reducing exchangeable aluminium (Alex) to 45% in the control soil. In the second experiment, all the organic amendments reduced soluble Al, but whereas straw increased soluble Fe, biochar diminished it. The amendment addition increased the soil pH and reduced Alex. The Alex reduction was greater for the stabler organic amendments: manure and biochar.
System Dynamics-Based Game Theoretical Analysis for Watershed Eco-Compensation Design: A Case Study in Tuojiang River, Sichuan Province, China
Authors: Min Xuefeng , Yu Yang , Zhao Rui , Xiong Xin , Du Sen , Mou Qin , Xu Wenjie
Published: August 2023

Eco-compensation is an important policy tool to trade off economic development and environmental protection in a watershed. This study introduced the gross ecosystem product (GEP) accounting system to identify the eco-compensation provider (ECP) and eco-compensation receiver (ECR) of a river basin. Then, a cooperative game model and a non-cooperative game model between the ECP and the ECR were established, in which system dynamics was incorporated into the game theoretical analysis to aid selection of the optimal compensation scheme. The study further demonstrated the model applications by taking the Tuojiang River Basin as a case. The results showed that the accounted GEP increased from CNY 32.2 billion in 2018 to CNY 35.5 billion in 2020, with a growth rate of 10.2%. Deyang City, as an ECP, had a cumulative difference of CNY 11.759 billion between its accounted GEP and actual GEP output over the three years. Neijiang City, Zigong City, and Luzhou City were taken as the ECR, receiving the GEP revenues as CNY 11.289 billion, 7.661 billion, and 1.497 billion, respectively. Chengdu City changed from the ECP to the ECR and ultimately to the ECP. However, Ziyang City and Meishan City changed from the ECP to the ECR. The eco-compensations increased to varying degrees during 2018–2020 in both game scenarios, with ECP payments and ECR revenues increasing by 16.5% and 4.6% in the non-cooperative game and by 5.0% and 50.8% in the cooperative game. Particularly, the eco-compensation obtained by the cooperative game had better environmental and economic performance, as there was a total of CNY 7.049 billion being saved. However, there was no savings of compensation by the non-cooperative game. It is expected that the results may provide insight into the design of the eco-compensation standard for a river basin.
Erosion Control Performance of Improved Soil Management in Olive Groves: A Field Experimental Study in NE Portugal
Authors: Santos Renecleide , Fonseca Felícia , Baptista Paula , Paz-González Antonio , de Figueiredo Tomás
Published: August 2023

Olive groves rank among the cropping systems facing higher erosion risk in Mediterranean Europe. The adoption of erosion control soil management practices is key for reducing such risk and driving olive production towards sustainability. This field experimental study aimed to quantify the erosion control performance of improved soil management as compared to conventional soil management in olive groves of NE Portugal. The design aimed to compare the effects of introducing no-tillage (NT) to a conventionally managed (T) olive grove and those with complementing ground cover by adventitious species (NS) with a sown cover (S) and comprised four treatments: TNS (reference for conventional), TS, NTNS and NTS. Erosion microplots (4 m2) were installed (two per treatment), recording soil loss, runoff and ground cover in seven erosion events throughout one year. The best erosion control performance was found in NTNS (low-cost improved soil management treatment) with 50% and 85% reductions in soil loss, respectively, in the annual total and in erosion events following large precipitation periods. Plots with adventitious vegetation ground cover performed better in soil loss control than the sown ones. Converting to no-tillage, as compared to sowing herbaceous vegetation to increase ground cover, proved more performant and less hazardous for improving erosion control in olive groves.
Algae-Derived Natural Products in Diabetes and Its Complications—Current Advances and Future Prospects
Authors: Pereira Leonel , Valado Ana
Published: August 2023

Diabetes poses a significant global health challenge, necessitating innovative therapeutic strategies. Natural products and their derivatives have emerged as promising candidates for diabetes management due to their diverse compositions and pharmacological effects. Algae, in particular, have garnered attention for their potential as a source of bioactive compounds with anti-diabetic properties. This review offers a comprehensive overview of algae-derived natural products for diabetes management, highlighting recent developments and future prospects. It underscores the pivotal role of natural products in diabetes care and delves into the diversity of algae, their bioactive constituents, and underlying mechanisms of efficacy. Noteworthy algal derivatives with substantial potential are briefly elucidated, along with their specific contributions to addressing distinct aspects of diabetes. The challenges and limitations inherent in utilizing algae for therapeutic interventions are examined, accompanied by strategic recommendations for optimizing their effectiveness. By addressing these considerations, this review aims to chart a course for future research in refining algae-based approaches. Leveraging the multifaceted pharmacological activities and chemical components of algae holds significant promise in the pursuit of novel antidiabetic treatments. Through continued research and the fine-tuning of algae-based interventions, the global diabetes burden could be mitigated, ultimately leading to enhanced patient outcomes.
Clinical and Dermoscopic Findings of Nevi after Photoepilation: A Review
Authors: Dessinioti Clio , Tsiakou Andriani , Christodoulou Athina , Stratigos Alexander J.
Published: August 2023

Atypical clinical and dermoscopic findings, or changes in pigmented melanocytic lesions located on body areas treated with lasers or intense pulsed light (IPL) for hair removal (photoepilation), have been described in the literature. There are three prospective studies in a total of 79 individuals with 287 melanocytic nevi and several case reports reporting the dermoscopic findings and changes after photoepilation. Clinical changes have been reported in 20–100% of individuals, while dermoscopic changes have been observed in 48% to 93% of nevi. More frequent dermoscopic changes included bleaching, the development of pigmented globules, and irregular hyperpigmented areas and regression structures, including gray areas, gray dots/globules, and whitish structureless areas. The diagnostic approach for pigmented lesions with atypical dermoscopic findings and changes after photo-epilation included reflectance confocal microscopy, sequential digital dermoscopy follow-up, and/or excision and histopathology. Challenges pertaining to these diagnostic steps in the context of photoepilation include the detection of findings that may warrant a biopsy to exclude melanoma (ugly duckling, irregular hyperpigmented areas, blue-gray or white areas, and loss of pigment network), the potential persistence of changes at follow-up, and that a histopathologic diagnosis may not be possible due to the distortion of melanocytes or complete regression of the lesion. Furthermore, these diagnostic approaches can be time-consuming, require familiarization of the physician with dermoscopic features, may cause anxiety to the individual, and highlight that avoiding passes of the laser or IPL devices over pigmented lesions is key.
Selection and Characterization of Bacteriocinogenic Lactic Acid Bacteria from the Intestine of Gilthead Seabream (Sparus aurata) and Whiting Fish (Merlangius merlangus): Promising Strains for Aquaculture Probiotic and Food Bio-Preservation
Authors: Cheriet Sarah , Lengliz Sana , Romdhani Amel , Hynds Paul , Abbassi Mohamed Salah , Ghrairi Taoufik
Published: August 2023

This study sought to evaluate the probiotic properties and the food preservation ability of lactic acid bacteria isolates collected from the intestines of wild marine fishes (gilthead seabream (Sparus aurata) (n = 60) and whiting fish (Merlangius merlangus) (n = 40)) from the Mediterranean sea in the area of Mostaganem city, Algeria. Forty-two isolates were identified as: Enterococcus durans (n = 19), Enterococcus faecium (n = 15), Enterococcus faecalis (n = 4), Lactococcus lactis subp. lactis (n = 3), and Lactobacillus plantarum (n = 1). All isolates showed inhibition to at least one indicator strain, especially against Listeria monocytogenes, Staphylococcus aureus, Paenibacillus larvae, Vibrio alginolyticus, Enterococcus faecalis, Bacillus cereus, and Bacillus subtilis. In all collected isolates, PCR analysis of enterocin-encoding genes showed the following genes: entP (n = 21), ent1071A/B (n = 11), entB (n = 8), entL50A/B (n = 7), entAS48 (n = 5), and entX (n = 1). Interestingly, 15 isolates harbored more than one ent gene. Antimicrobial susceptibility, phenotypic virulence, and genes encoding virulence factors were investigated by PCR. Resistance to tetracycline (n = 8: tetL + tetK), erythromycin (n = 7: 5 ermA, 2 msrA, and 1 mef(A/E)), ciprofloxacin (n = 1), gentamicin (n = 1: aac(6′)-aph(2″)), and linezolid (n = 1) were observed. Three isolates were gelatinase producers and eight were α-hemolytic. Three E. durans and one E. faecium harbored the hyl gene. Eight isolates showing safety properties (susceptible to clinically relevant antibiotics, free of genes encoding virulence factors) were tested to select probiotic candidates. They showed high tolerance to low pH and bile salt, hydrophobicity power, and co-culture ability. The eight isolates showed important phenotypic and genotypic traits enabling them to be promising probiotic candidates or food bio-conservers and starter cultures.
Agonal Thrombus at Necropsy—A Third Category of Blood Coagulation in Domestic Carnivores
Authors: Tiu Raluca Elena , Rizac Raluca Ioana , Nicolae George Laurentiu , Turbatu Raluca Mihaela , Ciobotaru-Pirvu Emilia
Published: August 2023

Agonal thrombus is infrequently discussed in veterinary forensic pathology, being misdiagnosed as postmortem coagulation. The main purpose of the present study is to confirm that agonal thrombosis is an important tool in ruling out sudden death and to characterize it by gross, histological, and immunohistochemical approaches. The investigations have been conducted on 56 domestic carnivores. Fibrin was observed as rosette—like arrangements around platelet aggregates, loose network, wave—like pattern or short fibers and the additional tendency of lines of Zahn being noted inconsistently. All agonal thrombi had positive reactions for anti—CD61 for platelets, disposed in variable—sized clumps or in a linear pattern close to endothelial cells of endocardium. The same positive reaction has been noted to anti—fibrinogen and anti—fibrin antibodies. CD45, CD68 and von Willebrand factor had a very low to absent expression. Cardiac lesions were found in 22 cases (39.29%) suggesting predisposition to agonal thrombosis in animals with cardiovascular diseases. The results prove that agonal thrombus is a third category of blood coagulation that forms strictly during agonal death. The microscopical findings describe the agonal thrombus similar to the morphology of recent thrombus vera. Given the results, the agonal thrombus is a useful tool that confirms the agonal suffering prior to death.
Advances in the Cystic Fibrosis Drug Development Pipeline
Authors: Esposito Christine , Kamper Martin , Trentacoste Jessica , Galvin Susan , Pfister Halie , Wang Janice
Published: August 2023

Cystic fibrosis is a genetic disease that results in progressive multi-organ manifestations with predominance in the respiratory and gastrointestinal systems. The significant morbidity and mortality seen in the CF population has been the driving force urging the CF research community to further advance treatments to slow disease progression and, in turn, prolong life expectancy. Enormous strides in medical advancements have translated to improvement in quality of life, symptom burden, and survival; however, there is still no cure. This review discusses the most current mainstay treatments and anticipated therapeutics in the CF drug development pipeline within the mechanisms of mucociliary clearance, anti-inflammatory and anti-infective therapies, restoration of the cystic fibrosis transmembrane conductance regulator (CFTR) protein (also known as highly effective modulator therapy (HEMT)), and genetic therapies. Ribonucleic acid (RNA) therapy, gene transfer, and gene editing are being explored in the hopes of developing a treatment and potential cure for people with CF, particularly for those not responsive to HEMT.
Evaluation of the Effects of Radiation Therapy on Muscle Contractibility and Skin Healing: An Experimental Study of the Cancer Treatment Implications
Authors: Avelino Sarah O. M. , Neves Rafael M. , Sobral-Silva Leonardo A. , Tango Rubens N. , Federico Claudio A. , Vegian Mariana R. C. , de Almeida-Silva Luis Augusto , Kaminagakura Estela , Amorim José Benedito O. , Vasconcellos Luana M. R.
Published: August 2023

Background: Radiotherapy can affect healthy cells, resulting in side effects. This study aimed to assess the impact of radiotherapy on soft tissue in surgical wounds in rats. Methods: The animals were divided into four groups: control (S) group without irradiation, immediate irradiation (S-IIr) group receiving irradiation right after surgery, late irradiation (S-LIr) group receiving irradiation four weeks after surgery, and early irradiation (Ir-S) group receiving irradiation before surgery. The irradiated groups underwent two fractional stages of 15 Gy. Muscle contractibility (EMG) was evaluated at two different time points, and after 2 and 7 weeks, the animals were euthanized for histological analysis of the muscles and skin. Results: There was no significant difference between the EMG1 and EMG2 values of the S and S-LIr groups, but both S-IIr and Ir-S groups exhibited a statistically significant difference. The S group demonstrated a larger diameter of muscle fiber compared to other groups, showing a significant difference. In terms of skin analysis, the S-IIr group had the least inflammatory infiltrate and the highest amount of red fibers, differing significantly from the other groups. Conclusions: Regardless of the duration, radiotherapy was found to have effects on the surrounding soft tissues, as concluded by this study.
Anti-Yeasts, Antioxidant and Healing Properties of Henna Pre-Treated by Moist Heat and Molecular Docking of Its Major Constituents, Chlorogenic and Ellagic Acids, with Candida albicans and Geotrichum candidum Proteins
Authors: Alsalamah Sulaiman A. , Alghonaim Mohammed Ibrahim , Jusstaniah Mohammed , Abdelghany Tarek M.
Published: August 2023

Lawsonia inermis, known as henna, has traditionally been utilized in cosmetics and folk medicine because of their valuable health effects. A lack of information about the processes that increase or decrease release, as well as the biological activities of constituents of natural origin, is an important pharmacological problem. This investigation evaluates the influence of moist heat on the flavonoid and phenolic contents of henna powder and their biological activities. HPLC analysis reflected the existence of 20 and 19 compounds of flavonoids and phenolics in the extract of unpre-treated henna by moist heat (UPMH) and pre-treated henna by moist heat (PMH). Several compounds such as chlorogenic acid, ellagic acid, rutin, rosmarinic acid, kaempferol, and pyrocatechol occurred with high concentrations of 57,017.33, 25,821.09, 15,059.88, 6345.08, 1248.42, and 819.19 µg/mL UPMH while occurred with low concentrations of 44,286.51, 17,914.26, 3809.85, 5760.05, 49.01, and 0.0 µg/mL, respectively in PMH. C. albicans, C. tropicalis, and G. candidum were more affected by UPMH with inhibition zones of 30.17 ± 0.29, 27 ± 0.5, and 29 ± 1.5 mm than PMH with inhibition zones of 29 ± 0.5, 25.33 ± 0.58, and 24.17 ± 0.29 mm, respectively. UPMH henna exhibited less MIC and MFC against the tested yeasts than PMH. Moreover, UPMH henna showed good wound healing, where the rat of migration, wound closure %, and area difference % were 14.806 um, 74.938 um2, and 710.667% compared with PMH henna 11.360 um, 59.083 um2, 545.333%, respectively. Antioxidant activity of UPMH and PMH henna. Promising antioxidant activity was recorded for both UPMH or PMH henna with IC50 5.46 µg/mL and 7.46 µg/mL, respectively. The docking interaction of chlorogenic acid and ellagic acid with the crystal structures of G. candidum (4ZZT) and C. albicans (4YDE) was examined. The biological screening demonstrated that the compounds had favorable docking results with particular proteins. Chlorogenic acid had robust behavior in the G. candidum (4ZZT) active pocket and displayed a docking score of −7.84379 Kcal/mol, higher than ellagic acid’s −6.18615 Kcal/mol.
Research Progress on Cu–15Ni–8Sn Alloys: The Effect of Microalloying and Heat Treatment on Microstructure and Properties
Authors: Yang Shaodan , Song Kexing , Zhou Yanjun , Yang Ran , Yu Yan , Liu Lele , Chen Jidong , Zhou Fei , Yang Wenhao , Zhang Guoshang , Du Juan
Published: August 2023

Cu–15Ni–8Sn alloy is the best choice to replace beryllium bronze alloy. This alloy has unparalleled application value in aerospace, ocean engineering, electronic information, equipment manufacturing, and other fields. However, the application of Cu–15Ni–8Sn alloy is challenged and limited because of a series of problems in its preparation and processing, such as easy segregation, difficult deformation, and discontinuous precipitation. It is an effective way to improve the comprehensive properties of Cu–15Ni–8Sn alloy using alloying design and process optimization to control the as-cast, deformed, and heat-treated microstructures. At present, it is a hot spot for scholars to study. In this paper, the grade generation, system evolution, and preparation technology development of Cu–15Ni–8Sn alloy are comprehensively reviewed. The phase transformation sequence of the Cu–15Ni–8Sn alloy is discussed. The influence of the type, amount, and existing form of alloying elements on the strength of Cu–15Ni–8Sn alloy and its mechanism are systematically summarized. Furthermore, the latest research progress on the effects of solid solution, cold deformation, and aging on the phase structure transformation and mechanical properties of Cu–15Ni–8Sn alloy is summarized. Finally, the future development trend of the Cu–15Ni–8Sn alloy is projected. The research results of this paper can provide a reference for the control of the microstructure and properties of high-performance Cu–15Ni–8Sn alloys used in key fields, as well as the optimization of the preparation process and alloy composition.
Sintering Temperature Effect of Near-Zero Thermal Expansion Mn3Zn0.8Sn0.2N/Ti Composites
Authors: Zhou Yongxiao , Zhang Lianyu , Qian Jinrui , Qian Zhiying , Hao Baoxin , Cong Qiang , Zhou Chang
Published: August 2023

Metal matrix composites with near-zero thermal expansion (NZTE) have gained significant popularity in high-precision industries due to their excellent thermal stability and mechanical properties. The incorporation of Mn3Zn0.8Sn0.2N, which possesses outstanding negative thermal expansion properties, effectively suppressed the thermal expansion of titanium. Highly dense Mn3Zn0.8Sn0.2N/Ti composites were obtained by adjusting the fabrication temperature. Both composites fabricated at 650 °C and 700 °C exhibited NZTE. Furthermore, finite element analysis was employed to investigate the effects of thermal stress within the composites on their thermal expansion performance.
Comparison of TiO2 and ZnO for Heterogeneous Photocatalytic Activation of the Peroxydisulfate Ion in Trimethoprim Degradation
Authors: Náfrádi Máté , Alapi Tünde , Veres Bence , Farkas Luca , Bencsik Gábor , Janáky Csaba
Published: August 2023

The persulfate-based advanced oxidation process is a promising method for degrading organic pollutants. Herein, TiO2 and ZnO photocatalysts were combined with the peroxydisulfate ion (PDS) to enhance the efficiency. ZnO was significantly more efficient in PDS conversion and SO4•− generation than TiO2. For ZnO, the PDS increased the transformation rate of the trimethoprim antibiotic from 1.58 × 10−7 M s−1 to 6.83 × 10−7 M s−1. However, in the case of TiO2, the moderated positive effect was manifested mainly in O2-free suspensions. The impact of dissolved O2 and trimethoprim on PDS transformation was also studied. The results reflected that the interaction of O2, PDS, and TRIM with the surface of the photocatalyst and their competition for photogenerated charges must be considered. The effect of radical scavengers confirmed that in addition to SO4•−, •OH plays an essential role even in O2-free suspensions, and the contribution of SO4•− to the transformation is much more significant for ZnO than for TiO2. The negative impact of biologically treated domestic wastewater as a matrix was manifested, most probably because of the radical scavenging capacity of Cl− and HCO3−. Nevertheless, in the case of ZnO, the positive effect of PDS successfully overcompensates that, due to the efficient SO4•− generation. Reusability tests were performed in Milli-Q water and biologically treated domestic wastewater, and only a slight decrease in the reactivity of ZnO photocatalysts was observed.
Experimental Study on Long-Term Mechanical Properties and Durability of Waste Glass Added to OPC Concrete
Authors: Zhu Jichao , Meng Xinyu , Wang Baoyuan , Tong Qianhao
Published: August 2023

This study aims to achieve the sustainable utilization of waste glass resources through an investigation into the influence of three types of admixtures, namely waste glass powder (WGP) (G), waste glass powder–slag (G-S), and waste glass powder–fly ash (G-F), on the mechanical properties and durability performance of waste glass concrete. The experimental results demonstrate that the exclusive use of WGP as an admixture led to the relatively poor early compressive strength of the concrete, which decreased with an increase in dosage. However, at medium to long curing ages, the strength of the waste glass concrete could equal or even surpass that of ordinary concrete. When dual admixtures were employed, the G-S group exhibited higher compressive strength compared to the G-F group. Specifically, within the G-S group, a glass powder dosage of 15% yielded higher compressive strength, and after 180 days, the dual admixture groups exhibited greater strength than ordinary concrete (G0); the compressive strength of the tG1S1 group was 44.57 MPa, and that of the G0 group was 40.07 MPa. The chloride ion diffusion coefficient showed a varying trend with an increase in WGP dosage, initially decreasing and then increasing. The concrete’s resistance to erosion was maximized when the glass powder dosage reached 30%. As the WGP dosage increased, the overall frost resistance decreased. For a total dosage of 30%, the optimal glass powder dosage in both G-S and G-F groups was found to be 15%.
The Effects of the Pre-Anodized Film Thickness on Growth Mechanism of Plasma Electrolytic Oxidation Coatings on the 1060 Al Substrate
Authors: Gong Wanting , Ma Ruina , Du An , Zhao Xue , Fan Yongzhe
Published: August 2023

To increase the density of the micro-arc oxide coating, AA 1060 samples were pretreated with an anodic oxide film in an oxalic acid solution. Plasma electrolytic oxidation (PEO) was performed to investigate the effect of the thickness of the pre-anodic oxide film on the soft-sparking mechanism. The experimental results revealed that the PEO coating phases with different thicknesses of the pre-anodized films contained both Al and gamma–alumina (γ-Al2O3). The pre-anodized film changes the final morphology of the coating, accelerating the soft sparking transition and retaining the soft sparking. At a pre-anodized film thickness of ≤7.7 μm, the anodized films thickened before being broken through. When the pre-anodized film thickness was ≥13.1 μm, partial dissolution of the anodized films occurred before they were struck through. Two growth mechanisms for PEO coatings with different pre-anodized film thicknesses were proposed.
Investigation of Hydrogen and Oxygen Evolution on Cobalt-Nanoparticles-Supported Graphitic Carbon Nitride
Authors: Zabielaite Ausrine , Balciunaite Aldona , Upskuviene Daina , Simkunaite Dijana , Levinas Ramunas , Niaura Gediminas , Vaiciuniene Jurate , Jasulaitiene Vitalija , Tamasauskaite-Tamasiunaite Loreta , Norkus Eugenijus
Published: August 2023

This study focuses on fabricating cobalt particles deposited on graphitic carbon nitride (Co/gCN) using annealing, microwave-assisted and hydrothermal syntheses, and their employment in hydrogen and oxygen evolution (HER and OER) reactions. Composition, surface morphology, and structure were examined using inductively coupled plasma optical emission spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The performance of Co-modified gCN composites for the HER and OER were investigated in an alkaline media (1 M KOH). Compared to the metal-free gCN, the modification of gCN with Co enhances the electrocatalytic activity towards the HER and OER. Additionally, thermal annealing of both Co(NO3)2 and melamine at 520 °C for 4 h results in the preparation of an effective bifunctional Co3O4/gCN catalyst for the HER with the lower Eonset of −0.24 V, a small overpotential of −294.1 mV at 10 mA cm−2, and a low Tafel slope of −29.6 mV dec−1 in a 1.0 M KOH solution and for the OER with the onset overpotential of 286.2 mV and overpotential of 422.3 mV to achieve a current density of 10 mA cm−2 with the Tafel slope of 72.8 mV dec−1.
Study on the Deterioration Mechanism of Magnesium Oxychloride Cement under an Alkaline Environment
Authors: An Lingyun , Chang Chenggong , Yan Fengyun , Peng Jianhong
Published: August 2023

The deterioration process and deterioration mechanism of magnesium oxychloride cement (MOC) in an alkaline environment were studied using a scanning electron microscope (SEM), an X-ray diffractometer (XRD), a Fourier transform infrared spectrometer (FT-IR) and a micro-electro-hydraulic servo pressure testing machine to investigate the effects of soaking time in 10 wt.% NaOH solution on the macro- and micro-morphology, phase composition and compressive strength of MOC samples. The results show that the deterioration of MOC samples under an alkaline environment is mainly caused by the alkaline environment providing more OH− ions, which can react with 5Mg(OH)2·MgCl2·8H2O (P 5) in the sample. The resulting reaction gives rise to a faster decomposition of 5Mg(OH)2·MgCl2·8H2O (P 5) and a substantial reduction in the strength of the sample, and finally leads to a gradual deterioration of MOC samples. Meanwhile, immersion time exhibits a significant effect on MOC samples. The extension of immersion time coincides with more OH− ions entering the sample, and the greater presence of OH ions increases the likelihood that more P 5 will produce a hydrolysis reaction, further resulting in the increased deterioration of the sample. After soaking for 6 h in alkaline media, the main phase composition of the surface layer of an MOC sample changes to MgO and Mg(OH)2, and its microscopic morphology is also dominated by round sheets, giving rise to a sharp decrease in its compressive strength (52.2%). When the immersion time is prolonged to 72 h, OH− ions have already immersed into the inner core of the sample, causing the disappearance of P 5 from the whole sample. At the same time, both the surface and inner core of the sample exhibit a disc-shaped morphology, and chalking phenomena also appear on the surface of the sample. This reduces the compressive strength of the sample to 13.5 MPa, only 20% of its compressive strength in water. The compressive strength of the sample after 120 h of immersion is as low as 8.6 MPa, which is lower than that of the sample dipped in water for 21 days (9.5 MPa). As a result, the MOC samples studied in alkaline environments exhibit a faster deterioration rate, mainly because of a faster hydrolysis reaction by P 5, caused by more OH− ions.
Influence of Undergarments on the Comfort Level of Scoliosis Brace Wearers
Authors: Nagy Szabó Orsolya , Geršak Jelka , Koleszár András , Halász Marianna
Published: August 2023

Bracing has proven to be an effective method for the conventional treatment of scoliosis in young people. A brace, a therapeutic device, covers the upper body and promotes healing by applying pressure to specific areas. However, wearing a scoliosis brace negatively affects the user’s thermo-physiological well-being and often leads to discomfort. In this study, we investigated the influence of T-shirts as an undergarment on the thermo-physiological well-being of the brace wearer. For this purpose, we performed a comparative analysis of six T-shirts made from different special knitted fabrics. We carried out wearing tests in a computer-controlled climate chamber according to a predetermined protocol. The test subject wore the orthopedic brace over the different T-shirts at three different temperatures. The results indicate that the knitted fabrics of undergarments and environmental conditions considerably impact the wearer’s thermo-physiological comfort. In the tests, the T-shirts made from the selected functional fabrics performed very well. The T-shirt made from the classic cotton fabric containing elastane yarn also performed well and was the most environmentally friendly. Currently, due to its lower price and easier availability, this cotton T-shirt can be recommended for wearing under a scoliosis brace.
Quantification of Thread Engagement in Screw-Plate Interface of Polyaxial Locking System Using X-ray Computed Tomography
Authors: Bartkowiak Tomasz , Madalińska Daria , Mietliński Patryk , Kaczmarek Jakub , Gapiński Bartosz , Pelic Marcin , Paczos Piotr
Published: August 2023

This study demonstrates a new method for quantifying thread engagement in mechanical connections and verifies its applicability using biomedical implants under push-out tests. The focus is on orthopedic plate implants employed for bone fracture fixation, which, by design, allow off-axis screw insertion to accommodate different contact conditions. Thread engagement is crucial in determining connection strength and stability. In medical practice, off-axis screw placement is usually necessary due to bone geometries and implant plate rigidity. To address this, the study proposes a quantification method using non-destructive testing with X-ray micro-computed tomography and automated image processing, although tuning the image processing parameters is vital for accurate and reliable results. This enables detailed 3D models of screw-plate interfaces for precise thread engagement measurement. The results show that thread engagement decreases with both, increased off-axis insertion angles and higher torque during insertion. Correlation analysis reveals a strong relationship (R2 > 0.6) between average thread engagement and push-out strength, underscoring the importance of proper screw placement for stable fixation.
Revealing the Sound Transmission Loss Capacities of Sandwich Metamaterials with Re-Entrant Negative Poisson’s Ratio Configuration
Authors: Li Fangyi , Chen Yuanwen , Zhu Dachang
Published: August 2023

Due to the influence of mass law, traditional lightweight sandwich structures have struggled to surpass solid structures in sound insulation performance. To this end, we propose an acoustic metamaterial structure with a sandwich configuration based on the re-entrant negative Poisson’s ratio (NPR) structure and systematically investigate its sound transmission loss (STL) performance under incident plane wave conditions. We used the acoustic impedance tube method to experimentally study the sound insulation performance of the re-entrant NPR sandwich structure under free boundary conditions, and then established an acoustic analysis simulation model based on COMSOL Multiphysics software, which verified that the results obtained by the experiment and the numerical simulation were in good agreement. The results show that the sandwich structure exhibits excellent sound transmission loss performance in the studied frequency range (250–4000 Hz), and the overall sound insulation performance exceeds the curve of the mass theorem, basically achieving more than 20 dB when the sandwich thickness is 2 cm. Finally, we conduct parametric studies to establish a correlation between the geometric design of NPR sandwich structures and their sound transmission loss performance. The research shows that the changes of the length of the ribs, the distance from the ribs to the center of the unit, and the length of the upper wall and the lower wall have a significant impact on the sound insulation performance of the re-entrant NPR sandwich structure, while the change of the wall thickness basically will not affect the sound insulation performance of the sandwich structure. This research can provide practical ideas for the engineering application of noise suppression designs of lightweight structures.
Methods to Increase or Decrease Resistance to Photodegradation and Biodegradation of Polyurethane/Polyisocyanurate (PU/PIR) Foams
Authors: Liszkowska Joanna , Gozdecka Grażyna , Sitarz Magdalena
Published: August 2023

Two series of rigid polyurethane–polyisocyanurate (PU/PIR) foams were obtained. They were modified using powder fillers, such as industrial food cocoa (K5–K15 foam) and instant freeze-dried coffee (KR-KR15) added in amounts of 5, 10 and 15 wt.%. W foam (reference) was obtained without filler. The foams were degraded in a climate chamber for 1 week, 2 weeks or 3 weeks. Appropriate temperature, humidity and UV radiation were set in the chamber, which did not change throughout the degradation process. The foams were also degraded in an oven for two days at 120 °C. The foam tests carried out indicated, among others, on the decrease in compressive strength along with the increase in the residence time of the samples in the chamber. Degraded foams also changed color. Foams containing 5% and 10% of industrial cocoa or freeze-dried coffee were more susceptible to degradation. The addition of 15% coffee or cocoa slows down the degradation process. In the present study, industrial food cocoa and instant freeze-dried coffee were used as modifiers of rigid PU/PIR foam. These fillers have two functions: they accelerate the biodegradation of foams and have antioxidant properties.
Effect of Grain Structure and Quenching Rate on the Susceptibility to Exfoliation Corrosion in 7085 Alloy
Authors: Cao Puli , Li Chengbo , Zhu Daibo , Zhao Cai , Xiao Bo , Xie Guilan
Published: August 2023

The influence of grain structure and quenching rates on the exfoliation corrosion (EXCO) susceptibility of 7085 alloy was studied using immersion tests, optical microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and scanning transmission electron microscopy (STEM). The results show that as the cooling rate decreases from 1048 °C/min to 129 °C/min; the size of grain boundary precipitates (GBPs); the width of precipitate-free zones (PFZ); and the content of Zn, Mg, and Cu in GBPs rise, leading to an increase in EXCO depth and consequently higher EXCO susceptibility. Meanwhile, there is a linear relationship between the average corrosion depth and the logarithm of the cooling rate. Corrosion cracks initiate at the grain boundaries (GBs) and primarily propagate along the HAGBs. In the bar grain (BG) sample at lower cooling rates, crack propagation along the sub-grain boundaries (SGBs) was observed. Compared to equiaxed grain (EG) samples, the elongated grain samples exhibit larger GBPs, a wider PFZ, and minor compositional differences in the GBPs, resulting in higher EXCO susceptibility.
Development and Fabrication of Biocompatible Ti-Based Bulk Metallic Glass Matrix Composites for Additive Manufacturing
Authors: Chen Po-Sung , Tsai Pei-Hua , Li Tsung-Hsiung , Jang Jason Shian-Ching , Huang Jacob Chih-Ching , Lin Che-Hsin , Pan Cheng-Tang , Lin Hsuan-Kai
Published: August 2023

Ti-based metallic glasses have a high potential for implant applications. The feasibility of a new biocompatible Ti-based bulk metallic glass composite for selective laser melting (SLM) had been examined. Therefore, it is necessary to design a high-glass-forming-ability Ti-based metallic glass (∆Tx = 81 K, γ = 0.427, γm = 0.763), to fabricate a partial glass-formable spherical powder (the volume fraction of the amorphous phase in the atomized Ti-based powders being 73% [size < 25 μm], 61% [25–37 μm], and 50% [37–44 μm]), and establish an SLM parameter (a scan rate of 600 mm/s, a power of 120 W, and an overlap of 10%). The Ti42Zr35Si5Co12.5Sn2.5Ta3 bulk metallic glass composite was successfully fabricated through SLM. This study demonstrates that the TiZrSiCoSnTa system constitutes a promising basis for the additive manufacturing process in terms of preparing biocompatible metallic glass composites into complicated graded foam shapes.
Electrospun Nanofibers for Functional Food Packaging Application
Authors: Zhang Meng , Ahmed Adnan , Xu Lan
Published: August 2023

With the strengthening of the public awareness of food safety and environmental protection, functional food packaging materials have received widespread attention. Nanofibers are considered as promising packaging materials due to their unique one-dimensional structure (high aspect ratio, large specific surface area) and functional advantages. Electrospinning, as a commonly used simple and efficient method for preparing nanofibers, can obtain nanofibers with different structures such as aligned, core-shell, and porous structures by modifying the devices and adjusting the process parameters. The selection of raw materials and structural design of nanofibers can endow food packaging with different functions, including antimicrobial activity, antioxidation, ultraviolet protection, and response to pH. This paper aims to provide a comprehensive review of the application of electrospun nanofibers in functional food packaging. Advances in electrospinning technology and electrospun materials used for food packaging are introduced. Moreover, the progress and development prospects of electrospun nanofibers in functional food packaging are highlighted. Meanwhile, the application of functional packaging based on nanofibers in different foods is discussed in detail.
Operational and Material Causes of High-Pressure Turbine Disc Damage in the RD-33 Engine
Authors: Jóźwiak Stanisław , Kozakiewicz Adam , Kachel Stanisław , Zasada Dariusz
Published: August 2023

This paper presents an analysis of the causes of damage and fragmentation to the high-pressure turbine (HTP) disc of the RD-33 engine mounted in the MIG-29 aircraft. The authors have carried out an analysis of the changes to the structure of the disc material, both in the areas containing cracks and in the undamaged areas. The impact of structural changes on the alterations in the analysed strength properties along the disc radius was assessed. Material tests were correlated with the analysis of the recorded engine parameters, indicating potential causes of the HPT disc fragmentation.
The Synthesis and Thermoelectric Properties of the n-Type Solid Solution Bi2−xSbxTe3 (x < 1)
Authors: Galodé Amélie , Barbier Tristan , Gascoin Franck
Published: August 2023

Commercial Peltier cooling devices and thermoelectric generators mostly use bismuth telluride-based materials, specifically its alloys with Sb2Te3 for the p-type legs and its alloys with Bi2Se3 for the n-type legs. If the p-type materials perform with zT well above the unity around room temperature, the n-type counterpart is lacking efficiency in this temperature range, and has the disadvantage of containing selenium. Indeed, despite the fact that selenium is not environmentally benign and that its handling requires precautions, the use of selenium does not facilitate the optimization of thermoelectric performance at or around room temperature, as the presence of selenium results in a larger band gap. In this study, we investigate the feasibility of a selenium-free n-type (Bi, Sb)2Te3 using a simple two-step process: mechanical alloying synthesis followed by spark plasma sintering. All the members of the solid solution Bi2−xSbxTe3 with x < 1 are n-type materials, with zTs between 0.35 and 0.6. The zT is maximized at lower temperatures with an increasing Sb content, which is proof that the band gap is reduced accordingly. We also show here that an edge-free sintering process considerably improves thermoelectric performance.
Comparison of Thermal Deformation Behavior and Characteristics of Mg-Gd-Y-Zn Alloys with and without Bulk LPSO Phase
Authors: Chen Dongjie , Wang Qi , Zhang Liang , Li Ting , Yuan Jiawei , Shi Guoliang , Wang Xinyu , Zhang Kui , Li Yongjun
Published: August 2023

Alloys Mg-8Gd-4Y-0.6Zn-0.5Zr (referred to as 0.6Zn) without the bulk long-period stacking ordered (LPSO) phase and Mg-8Gd-4Y-1.1Zn-0.5Zr (referred to as 1.1Zn) containing the bulk LPSO phase were prepared and a series of hot compression tests were conducted to examine and evaluate the influence of the bulk LPSO phase on the thermal deformation behavior and characteristics of the Mg-Gd-Y-Zn-Zr alloy. The bulk LPSO phase affects the dynamic recrystallization behavior, resulting in differences in flow stress between two alloys under different conditions. Specifically, in the temperature range of 380~460 °C, compression at lower strain rates is beneficial for the LPSO phase to promote dynamic recrystallization, while compression at a high strain rate inhibits the dynamic recrystallization due to the severe deformation of the bulk LPSO phase to release the stress concentration instead. The increase in temperature helps the LPSO promote dynamic recrystallization. As a result, the LPSO phase promotes dynamic recrystallization at all experimental strain rates at 500 °C. Furthermore, the thermal processing maps of the 0.6Zn and 1.1Zn alloys are established, and their optimal processing windows are located at 500 °C/0.001~0.01 s−1 and 500 °C/0.01 s−1, respectively. In addition, the instability zones for the 1.1Zn alloy are much larger than that for the 0.6Zn alloy, which corresponds to the microcracks generated at the interfaces between α-Mg and bulk LPSO phases.
Dentin Bonding Performance of Universal Adhesives in Primary Teeth In Vitro
Authors: Danevitch Nina , Frankenberger Roland , Lücker Susanne , Gärtner Ulrich , Krämer Norbert
Published: August 2023

(1) Background: The aim of this in vitro study was to evaluate the micro-tensile bond strength (µ-TBS) of universal adhesives to primary tooth dentin after different storage periods. (2) Methods: Dentin of 100 extracted primary molars was exposed. Dentin surfaces were bonded with six universal adhesives (Adhese®Universal [AU], All-Bond Universal® [ABU], G-Premio Bond [GPB], iBond®Universal [IBU], Prime&Bond active™ [PBa], and Prime&Bond®NT as control [PBN]) and restored with a resin composite build-up (Filtek™ Z250). After 24 h, 6 months, and 12 months of water storage, specimens were cut into sticks, and µ-TBS was measured and analyzed using one-way ANOVA (p < 0.05) for normal distributions and the Mann–Whitney U-test (p < 0.05) for non-normal distribution. Pretesting failures were recorded as 0 MPa. Fracture modes were analyzed under a fluorescence microscope; interfaces were visualized with SEM/TEM. (3) Results: Compared with the reference group (PBN: 32.5/31.2 MPa after 6/12 months), two adhesives showed a significantly higher bond strength after 6 months (AU: 44.1 MPa, ABU: 40.9 MPa; p < 0.05) and one adhesive after 12 months (AU: 42.9 MPa, p < 0.05). GPB revealed significantly lower bond strengths in all storage groups (16.9/15.5/10.9 MPa after 24 h/6 months/12 months; p < 0.05). AU and IBU did not suffer pre-test-failures [PTF]. (4) Conclusions: After 12 months, PBN, IBU, AU, and GPB showed significantly lower results compared ithw initial µ-TBS, whereas AU revealed the highest µ-TBS and no PTF.
Effects of Material Structure on Stress Relaxation Characteristics of Rapidly Solidified Al-Fe Alloy
Authors: Kobayashi Ryohei , Funazuka Tatsuya , Maeda Toru , Shiratori Tomomi
Published: August 2023

An Al-Fe alloy which was produced by hot extrusion of rapidly solidified powder is a possible solution to substitute copper-based electrical conductor material due to its high strength and high electrical conductivity. However, the stress relaxation characteristic—an essential parameter as a conductor material—and the effect of the material structure have not been reported, which was the aim of the present paper. An Al-5%Fe alloy was selected as the test material. The material structures were controlled by hot extrusion practice, annealing, and cold rolling. The Al-Fe intermetallic compound particles controlled the residual stress after the stress relaxation test via the Orowan mechanism. Decreasing the mean inter-particle distance reduces the electrical conductivity. The increase in the number of dislocations by the cold rolling increased strength at room temperature without changing electrical conductivity; however, it did not have a positive effect on the stress relaxation characteristics. The stress relaxation characteristics and the electrical conductivity of the Al-Fe alloy were superior to conventional C52100 H04 phosphor bronze when compared with the case of the same mass.