bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of the Clinical Utility of Two Insulin Resistance Indices: IRI-HOMA and IRI-Belfiore in Diagnosing Insulin Resistance and Metabolic Complications in Children Based on the Results Obtained for the Polish Population
Authors: Łupińska Anna , Aszkiełowicz Sara , Kowalik Dorota , Jeziorny Krzysztof , Kolasa-Kicińska Marzena , Smalczewska Paula , Zygmunt Arkadiusz , Lewiński Andrzej , Stawerska Renata
Published: May 2024

Background: Recognizing insulin resistance (IR) in children remains challenging due to uncertain IRI-HOMA cut-offs and unclear recommendations for evaluating IR based on OGTT. In our study, we compare the effectiveness of IRI-HOMA and IRI-Belfiore (OGTT-based) in detecting IR and its metabolic complications in children. Methods: The analysis included 553 children who were hospitalized at the Department of Endocrinology and Metabolic Diseases of the Polish Mother’s Memorial Hospital Research Institute (PMMH-RI) in Lodz, Poland, between 2002 and 2018 due to various reasons—of these, 67.5% were girls. All underwent OGTT for glucose and insulin assessment. IR diagnosis relied on IRI-HOMA and IRI-Belfiore. IR based on IRI-HOMA was evaluated using three criteria: (A) >2.5; (B) >2.67 in boys and >2.22 in girls before puberty and >5.22 and >3.82 during puberty, respectively; (C) >95th percentile according to charts for IRI-HOMA in children. Results: Prepubertal children exhibited significantly lower IRI-HOMA and IRI-Belfiore than their pubertal counterparts (p < 0.00005). IRI-HOMA and IRI-Belfiore values positively correlated with age and BMI SDS value (p < 0.000001 for all calculations). As many as 26% to 46.9% of children with normal IRI-HOMA showed elevated IRI-Belfiore, with notably higher levels of triglycerides, a lower HDL cholesterol fraction, and a lower HDL/total cholesterol ratio in this subgroup. Conclusions: A notable proportion of children exhibited elevated IRI-Belfiore levels despite having normal IRI-HOMA values. This suggests the possibility of peripheral IR preceding hepatic IR in children—omitting an OGTT may therefore lead to overlooking cases of IR. Children diagnosed with IR via OGTT displayed significantly poorer lipid profiles compared to those without IR (characterized by normal values in both IRI-HOMA and IRI-Belfiore). This underscores the ability of OGTT-derived IR indices to identify individuals at risk of developing complications associated with obesity and IR before the onset of metabolic syndrome (MS) symptoms. If IR is already detected in children based on fasting glucose and insulin levels (IRI-HOMA), further evaluation may not be warranted, as OGTT results often simply confirm the diagnosis.
Combination of Supramicrosurgical Lymphatico-Venular Anastomosis (sLVA) and Lymph-Sparing Liposuction in Treating Cancer-Related Lymphedema: Rationale for a Regional One-Stage Approach
Authors: Gabriele Guido , Nigri Andrea , Chisci Glauco , Massarelli Olindo , Cascino Flavia , Komorowska-Timek Ewa , Kazuki Kikuchi , Hara Hisako , Mihara Makoto , Gennaro Paolo
Published: May 2024

Objective: Cancer-related lymphedema represents a potential complication of cancer treatment. The aim of this study is to evaluate the effectiveness of the combination of lymphatico-venular anastomosis and liposuction in the treatment of secondary lymphedema. Methods: We present a retrospective analysis of patients affected by cancer-related unilateral limb lymphedema. Inclusion criteria included previous neoplastic pathology with the consequent development of unilateral limb lymphedema, while the exclusion criteria included the presence of comorbidities and the persistence of cancer, as well as previous lymphatic surgery. The outcomes to be included were a reduction in the limb volume and lymphangitis rate, and an improvement in the quality of life. Patients’ data were assessed before surgery and 1 year after surgery. Perioperative management included clinical and ultrasonographical evaluations. Under local anesthesia, lymphatico-venular anastomosis with the supramicrosurgical technique and the liposuction of the affected limb was performed in the same surgical session. Results: A total of 24 patients were enrolled in the study. One year after the surgery, an average volume reduction of 37.9% was registered (p = 0.0000000596). The lymphangitis rate decreased after surgery from 4.67 to 0.95 per year (p = 0.000007899). The quality-of-life score improved from 68.7 to 16 according to the LLIS scale. Conclusions: The combination of LVA and liposuction represents a valid strategy for treating cancer-related lymphedema, ensuring stable results over time. In addition, it can be performed under local anesthesia, resulting in being minimally invasive and well-tolerated by patients. This paper reports on the short-term efficacy of this combined technique.
Reliability and Validity of the Spanish Version of the Brief-BESTest in Stroke Patients
Authors: Hernández-Moreda Beatriz , Llamas-Ramos Inés , Llamas-Ramos Rocío , Sánchez-González Juan Luis , Bermejo-Gil Beatriz María , Pérez-Robledo Fátima , Frutos-Bernal Elisa , Martín-Nogueras Ana María
Published: May 2024

Background: Balance disorders and postural control treatments play an important role in fall prevention. The Brief-BESTest is a short-scale employed to evaluate balance and fall risk in different populations. Balance assessment is a fundamental element in patients with Acquired Brain Injury rehabilitation since postural alteration is one of the most frequent sequelae. The objective was to validate the Spanish version of the Brief-BESTest questionnaire in the stroke population. Methods: Subjects of both sexes aged over 18 years with a diagnosis of acute/chronic stroke were included. The BESTest, Mini-BESTest, Brief-BESTest, Berg Balance Scale, and Timed Up & Go Test were used to assess balance. The scales were implemented once. Cronbach’s alpha coefficient was used to assess the internal consistency and confirmatory factorial analysis was employed to assess validity. Results: A total of 44 patients with a mean age of 65.35 years (SD = 10.665) participated. Cronbach’s alpha coefficient showed a high internal consistency with a value of 0.839. In the criterion validity, there was a high positive correlation between the Brief-BESTest and BESTest (r = 0.879), Mini-BESTest (r = 0.808), and Berg Balance Scale (r = 0.711). Conclusion: The Spanish version of the Brief-BESTest scale is valid and reliable, showing adequate psychometric properties for balance assessment in patients with acute or chronic stroke.
Contemporary Abdominal Wall Reconstruction: Emerging Techniques and Trends
Authors: Pogson-Morowitz Kaylyn , Porras Fimbres Denisse , Barrow Brooke E. , Oleck Nicholas C. , Patel Ash
Published: May 2024

Abdominal wall reconstruction is a common and necessary surgery, two factors that drive innovation. This review article examines recent developments in ventral hernia repair including primary fascial closure, mesh selection between biologic, permanent synthetic, and biosynthetic meshes, component separation, and functional abdominal wall reconstruction from a plastic surgery perspective, exploring the full range of hernia repair’s own reconstructive ladder. New materials and techniques are examined to explore the ever-increasing options available to surgeons who work within the sphere of ventral hernia repair and provide updates for evolving trends in the field.
Can ESG Integration Enhance the Stability of Disruptive Technology Stock Investments? Evidence from Copula-Based Approaches
Authors: Yu Poshan , Xu Haoran , Chen Jianing
Published: May 2024

This paper provides an investigation into the dependence structure among different disruptive technology sectors driving the Fourth Industrial Revolution and scrutinizes the impact of ESG integration on shaping investments in different tech stock sectors in the presence of ESG consideration, represented by the ESG stock index, versus without specific ESG consideration, represented by the general stock index. The results show that (i) C-vine outperforms R-vine and D-vine when modeling the dependence structure of tech sectors. Intelligent infrastructure is the most crucial sector, with substantial reliance on smart transportation and advanced manufacturing. (ii) ESG integration reduces dependence, especially tail dependence, between tech sectors and the stock market, which benefits the future security sector the most and future communication the least. (iii) ESG integration mitigates risk spillover between tech sectors and the stock market, particularly benefiting final frontiers and intelligent infrastructure. The decrease in downside spillover is more significant compared to upside scenarios. For downside risk, spillover from tech sectors to stock indices is more reduced than the reverse, while the opposite holds for upside risk. These sectoral findings offer insights for market participants in financial market investments, financial regulators in risk management, and listed companies in ESG disclosure.
Navigating Real Estate Investment Trust Performance Dynamics: The Role of Style (Equity vs. Mortgage Real Estate Investment Trusts) and Diversification Amidst the COVID-19 Pandemic
Authors: Damani Ankita , Nguyen Anh Tuan , Pratima FNU
Published: May 2024

In this paper, we investigate the impact of COVID-19 on different performance measures and the risk of US Real Estate Investment Trusts (REITs) with different styles. Our findings suggest a phenomenon with compelling evidence of reduced performance without any significant changes in risk profile amidst the COVID-19 pandemic. Particularly, mortgage REITs (MREITs) appear to be more adversely affected compared to equity REITs (EREITs). We further explore and analyze the performance of specialized REITs in contrast to diversified REITs in the distinctive conditions presented by COVID-19. We find that diversification creates value for the entire sample period, whereas, during the COVID-19 pandemic, property type specialization helps, although the results are weakly significant. The findings on risk suggest investors’ short-run outlook on market reaction. These results remain robust to additional tests. The implications provide insight for investors as a reference to reallocate assets in their portfolios during uncertain times.
Fostes tu?: Analogical Change in European Portuguese and the Case of the Second Person Singular in the Simple Past (Indicative)
Authors: Guilherme Ana
Published: May 2024

This paper sets out to study the second person–number marking in the (indicative) simple past in the history of European Portuguese, with a particular focus on morphological innovations such as fostes tu, which are considered deviant. These innovations, according to some brief descriptions in the literature (cf. Piel 1989; Williams 1994), are considered a case of morphological change by analogy; however, it remains to be determined whether it is a case of analogical extension or, possibly, leveling that would have resulted in syncretism. Based on data retrieved from private letters from the 16th to the 20th century by almost illiterate authors, we will argue that this innovation results from an analogical extension, motivated by morphological and pragmatic factors.
Phase Composition of HiVac-VPE Lithium Niobate Optical Waveguides Identified by Spectroscopic Investigations
Authors: Rambu Alicia Petronela , Kostritskii Sergey , Fedorov Vyacheslav , Sevostyanov Oleg , Chirkova Irina , Tascu Sorin
Published: May 2024

High-index contrast lithium niobate waveguides, fabricated by the High Vacuum Vapor-phase Proton Exchange (HiVac-VPE) technique, are very promising for increasing both the optical nonlinear and electro-optical efficiencies of photonic integrated devices. So as to play this role effectively, it is mandatory to know the crystallographic phase composition of waveguides and the position of protonated layers for appropriate tailoring and optimization based on the intended applications. In addition, the estimation of structural disorder and electro-optical properties of the waveguides are also of high interest. Benefiting from Raman spectroscopy, IR reflection, IR absorption, and UV-VIS absorption, the HxLi1−xNbO3 phase compositions, as well as the structural disorder in waveguides, were determined. Based on experimental data on the shift of the fundamental absorption edge, we have quantitatively estimated the electro-optic coefficient r13 in as-exchanged waveguides. The electro-optical properties of the waveguides have been found to be depending on the phase composition. The obtained results allow for reconsidering the proton exchange fabricating process of photonic nonlinear devices and electro-optic modulators based on high-index contrast channel waveguides on the LiNbO3 platform.
Sideritis raeseri—Modified Coatings on Ti-6Al-4V as a Carrier for Controlled Delivery Systems of Active Substances
Authors: Niziołek Karina , Słota Dagmara , Sadlik Julia , Kosińska Edyta , Korzeń Klaudia , Jampilek Josef , Sobczak-Kupiec Agnieszka
Published: May 2024

The search for the ideal metallic material for an implant is still a difficult challenge for scientists due to the phenomenon of corrosion and the consequent disruption of the implant structure. Prevention is the application of coatings that protect the implant, activate the tissues for faster regeneration, and also prevent inflammation through antibacterial and antiviral effects. The present study focuses on the selection of components for a Ti-6Al-4V alloy coating. These days, researchers are taking an intense interest in extracts of natural origin. It was decided to take a look at Sideritis raeseri, which contains vitamins and valuable elements and is rich in polyphenols, as well as antioxidants. The composition of coatings based on a PEG polymer reinforced with brushite and the S. raeseri extract with the proteins L-carnosine, fibroin, or sericin was developed. The samples were subjected to detailed physiochemical analysis, including potentiometry and electrical conductivity analysis, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and UV-VIS spectroscopy. The study demonstrated that polyphenols were successfully released from the coatings during incubation in vitro. The osteointegration process can be supported by a number of factors, such as the release of polyphenols from implant coatings to prevent bacterial, viral, and fungal infections. Subjecting the samples to 14 days of incubation demonstrated their interactions with the incubation fluids, an ion exchange between the medium and the materials. An analysis of the surface morphology exhibited the presence of brushite crystals and their increased number after incubation, indicating the bioactivity of the formed coatings.
Effect of a Hybrid Pumice–Portland Cement Extract on Corrosion Activity of Stainless Steel SS304 and Carbon Mild Steel A36
Authors: Bonfil David , Veleva Lucien , Escalante-Garcia Jose Ivan
Published: May 2024

The change in the corrosion activities of SS304 and the carbon steel A36 were studied during their exposure for 30 days to hybrid pumice-Portland cement extract (CE), to simulate the concrete–pore environment. The ionic composition and the initial pH (12.99) of the CE were influenced by the reduction of Portland cement (PC) content, volcanic pumice oxides and alkaline activators. Because of the air CO2  dissolution, the pH decreased and maintained a constant value ≈ 9.10 (established dynamic ionic equilibrium). The CE promoted the passivation of both steels and their free corrosion potential (OCP) reached positive values. On the surfaces, Fe and Cr oxides were formed, according to the nature of the steel. Over the time of exposure, the presence of chloride ions in the pumice caused a localized pitting attack, and for carbon steel, this fact may indicate an intermediate risk of corrosion. The chloride effect was retarded by the accumulation of SO42− ions at the steel surfaces. Based on electrochemical impedance (EIS), the polarization resistance (Rp) and the thickness of the passive layers were calculated. Their values were compared with those previously reported for the steels exposed to CEs of Portland and supersulfated cements, and the hybrid cement was considered as a PC “green” alternative.
Experimental Investigation on the Impact of Graphite Electrodes Grain Size on Technological Parameters and Surface Texture of Hastelloy C-22 after Electrical Discharge Machining with Negative Polarity
Authors: Nowicki Rafał , Oniszczuk-Świercz Dorota , Świercz Rafał
Published: May 2024

Electrical discharge machining (EDM) is a rapidly evolving method in modern industry that manufactures highly complex components. The physical properties of a tool electrode material are significant factors in determining the effectiveness of the process, as well as the characteristics of the machined surfaces. The current trend of implementing graphite tool electrodes in manufacturing processes is observed. Innovative material engineering solutions enable graphite production with miniaturized grain size. However, the correlation between the graphite electrode grain size and the mechanism of the process removal in the EDM is a challenge for its widespread implementation in the industry. This research introduces a new method to evaluate the impact of the graphite electrode grain size and machining parameters on the material removal effectiveness, relative tool wear rate, and surface roughness (Ra) of Hastelloy C-22 following EDM with negative polarity. The study utilized new graphite materials with a grain size of 1 µm (POCO AF-5) and 10 µm (POCO EDM-180). An assessment of the impact of the EDM process parameters on the technological parameters and the development of the surface roughness was carried out. Electrical discharge machining with fine-grained graphite electrodes increases process efficiency and reduces tool wear. Graphite grains detached from the tool electrode affect the stability of electrical discharges and the efficiency of the process. Based on the experimental results, mathematical models were developed, enabling the prediction of machining effects to advance state-of-the-art manufacturing processes. The obtained mathematical models can be implemented in modern industrial EDM machines as guidelines for selecting adequate machining parameters depending on the desired process efficiency, tool wear rate, and surface roughness for advanced materials.
The Influence of Cyclic Thermal Shocks at High Temperatures on the Microstructure, Hardness and Thermal Diffusivity of the Rene 41 Alloy
Authors: Ungureanu Arva Elisabeta Roxana , Negrea Denis Aurelian , Galatanu Andrei , Galatanu Magdalena , Moga Sorin Georgian , Anghel Daniel-Constantin , Branzei Mihai , Stoica Livia , Jinga Alexandra Ion , Petrescu Mircea Ionut , Munteanu Corneliu , Abrudeanu Marioara
Published: May 2024

The precipitation-hardenable nickel-based superalloy Rene 41 exhibits remarkable mechanical characteristics and high corrosion resistance at high temperatures, properties that allow it to be used in high-end applications. This research paper presents findings on the influence of thermal shocks on its microstructure, hardness, and thermal diffusivity at temperatures between 700 and 1000 °C. Solar energy was used for cyclic thermal shock tests. The samples were characterized using microhardness measurements, optical microscopic analysis, scanning electron microscopy coupled with EDS elemental chemical analysis, X-ray diffraction, and flash thermal diffusivity measurements. Structural transformations and the variation of properties were observed with an increase in the number of shocks applied at the same temperature and with temperature variation for the same number of thermal shocks.
Chloride Corrosion Process of Concrete with Different Water–Binder Ratios under Variable Temperature Drying–Wetting Cycles
Authors: Wang Lei , Chen Chunhong , Liu Ronggui , Zhu Pinghua , Liu Hui , Jiang Hongwei , Yu Jiang
Published: May 2024

In this paper, four water–binder ratios (w/b) of 0.29, 0.33, 0.39, and 0.46 were designed. A variable test temperature was implemented in the drying–wetting cycle test according to the temperature fluctuations in the actual service environment, and the constant temperature test was established as the control group. The mechanical properties and chloride corrosion resistance of concrete with different w/b ratios under variable temperature drying–wetting cycles, as well as the microstructure changes, phase composition, and damage mechanism inside the concrete, were investigated. The results showed that the mechanical properties of concrete increased first and then decreased with drying–wetting cycles increasing, whereas the chloride corrosion resistance continued to decline. A higher w/b exacerbated the deterioration of the concrete performance. A higher w/b increased the porosity, chloride diffusion depth, and chloride content, thus reducing the resistance of chloride corrosion. Compared with w/b = 0.29, the compressive strength, splitting tensile strength, mass, and relative dynamic elasticity modulus of w/b = 0.46 exposed to 60 drying–wetting cycles decreased by 54.50%, 52.44%, 0.96%, and 6.50%, respectively, while the porosity, peak chloride content, and erosion depth increased by 45.12%, 70.45%, and 45.00%. Compared with the drying–wetting cycle with a constant temperature, the cumulative damage caused by the drying–wetting cycle with a variable temperature was greater, resulting in more severe deterioration of concrete performance. The increase in the test temperature significantly accelerated the diffusion rate, penetration depth, and chemical binding capacity of chloride ions. After 60 drying–wetting cycles, the peak chlorine content and erosion depth of w/b = 0.46 under variable temperature cycles were 15.38% and 10.32% higher than those under a constant temperature, while the compressive strength, splitting tensile strength, mass, and relative dynamic elastic modulus were reduced by 7.76%, 14.81%, 0.33%, and 2.40%, respectively. Microscopic analysis confirmed that higher w/b and variable temperature cycles accelerated the decay of mechanical properties and the decline of chloride corrosion resistance. According to the numerical fitting analysis, the w/b should be 0.29~0.39 under the condition that the mechanical properties and chloride corrosion resistance of concrete are met.
Conductive Gels for Energy Storage, Conversion, and Generation: Materials Design Strategies, Properties, and Applications
Authors: Bari Gazi A. K. M. Rafiqul , Jeong Jae-Ho , Barai Hasi Rani
Published: May 2024

Gel-based materials have garnered significant interest in recent years, primarily due to their remarkable structural flexibility, ease of modulation, and cost-effective synthesis methodologies. Specifically, polymer-based conductive gels, characterized by their unique conjugated structures incorporating both localized sigma and pi bonds, have emerged as materials of choice for a wide range of applications. These gels demonstrate an exceptional integration of solid and liquid phases within a three-dimensional matrix, further enhanced by the incorporation of conductive nanofillers. This unique composition endows them with a versatility that finds application across a diverse array of fields, including wearable energy devices, health monitoring systems, robotics, and devices designed for interactive human-body integration. The multifunctional nature of gel materials is evidenced by their inherent stretchability, self-healing capabilities, and conductivity (both ionic and electrical), alongside their multidimensional properties. However, the integration of these multidimensional properties into a single gel material, tailored to meet specific mechanical and chemical requirements across various applications, presents a significant challenge. This review aims to shed light on the current advancements in gel materials, with a particular focus on their application in various devices. Additionally, it critically assesses the limitations inherent in current material design strategies and proposes potential avenues for future research, particularly in the realm of conductive gels for energy applications.
Comparison of MAF-32 and a One-Pot Synthesized Superparamagnetic Iron Oxide/MAF-32 Composite for the Adsorption of Diclofenac
Authors: Ramírez Erick , Carmona-Pérez Daniela , Marco J. F. , Sanchez-Lievanos Karla R. , Sabinas-Hernández Sergio A. , Knowles Kathryn E. , Elizalde-González María P.
Published: May 2024

The global presence of pharmaceutical pollutants in water sources represents a burgeoning public health concern. Recent studies underscore the urgency of addressing this class of emerging contaminants. In this context, our work focuses on synthesizing a composite material, FexOy/MAF-32, through a streamlined one-pot reaction process, as an adsorbent for diclofenac, an emerging environmental contaminant frequently found in freshwater environments and linked to potential toxicity towards several organisms such as fish and mussels. A thorough characterization was performed to elucidate the structural composition of the composite. The material presents magnetic properties attributed to its superparamagnetic behavior, which facilitates the recovery efficiency of the composite post-diclofenac adsorption. Our study further involves a comparative analysis between the FexOy/MAF-32 and a non-magnetic counterpart, comprised solely of 2-ethylimidazolate zinc polymer. This comparison aims to discern the relative advantages and disadvantages of incorporating magnetic iron oxide nanoparticles in the contaminant removal process facilitated by a coordination polymer. Our findings reveal that even a minimal incorporation of iron oxide nanoparticles substantially enhanced the composite’s overall performance in pollutant adsorption.
Residual Stress Evaluation in L-PBF-Produced SS 316L Specimens
Authors: Geľatko Matúš , Hatala Michal , Botko František , Vandžura Radoslav
Published: May 2024

The identification of residual stresses (RS) in components made by selective laser melting (SLM) is necessary for subsequent technological optimization. The presented research is devoted to evaluating the influence of the combination of laser power (P), scanning velocity (v) and the rarely considered number of layers (nL) on surface residual stresses in SLM stainless steel SS 316L. Experimental parameters were set based on the Design of Experiment (DoE) method, with follow-up X-ray diffraction (XRD) measurements and data processing using analysis of variance (ANOVA) and regression analysis. The obtained data are a valuable stepping-stone for the subsequent design of research focused on the application of sustainable eco-friendly Abrasive Water Jet (AWJ) peening for RS modification in the evaluated material.
Additively Manufactured Bionic Corrugated Lightweight Honeycomb Structures with Controlled Deformation Load-Bearing Properties
Authors: Li Jie , Wang Han , Kong Xianghao , Jiao Zhiwei , Yang Weimin
Published: May 2024

The rapid development of additive manufacturing (AM) has facilitated the creation of bionic lightweight, energy-absorbing structures, enabling the implementation of more sophisticated internal structural designs. For protective structures, the utilization of artificially controlled deformation patterns can effectively reduce uncertainties arising from random structural damage and enhance deformation stability. This paper proposed a bionic corrugated lightweight honeycomb structure with controllable deformation. The force on the onset state of deformation of the overall structure was investigated, and the possibility of controlled deformation in the homogeneous structure was compared with that in the corrugated structure. The corrugated structures exhibited a second load-bearing capacity wave peak, with the load-bearing capacity reaching 60.7% to 117.29% of the first load-bearing peak. The damage morphology of the corrugated structure still maintained relative integrity. In terms of energy absorption capacity, the corrugated lightweight structure has a much stronger energy absorption capacity than the homogeneous structure due to the second peak of the load carrying capacity. The findings of this study suggested that the combination of geometric customization and longitudinal corrugation through additive manufacturing offers a promising approach for the development of high-performance energy-absorbing structures.
Effect of Alloying Elements on the High-Temperature Yielding Behavior of Multicomponent γ′-L12 Alloys
Authors: Wang Chen-Yuan , Matsunaga Sae , Toda Yoshiaki , Murakami Hideyuki , Yeh An-Chou , Yamabe-Mitarai Yoko
Published: May 2024

The exceptional mechanical properties of Ni-based high entropy alloys are due to the presence of ordered L12 (γ′) precipitates embedded within a disordered matrix phase. While the strengthening contribution of the γ′ phase is generally accepted, there is no consensus on the precise contribution of the individual strengthening mechanisms to the overall strength. In addition, changes in alloy composition influence several different mechanisms, making the assessment of alloying conditions complex. Multicomponent L12-ordered single-phase alloys were systematically developed with the aid of CALPHAD thermodynamic calculations. The alloying elements Co, Cr, Ti, and Nb were chosen to complexify the Ni3Al structure. The existence of the γ′ single phase was validated by microstructure characterization and phase identification. A high-temperature compression test from 500 °C to 1000 °C revealed a positive temperature dependence of strength before reaching the peak strength in the studied alloys NiCoCrAl, NiCoCrAlTi, and NiCoCrAlNb. Ti and Nb alloying addition significantly enhanced the high-temperature yield strengths before the peak temperature. The yield strength was modeled by summing the individual effects of solid solution strengthening, grain boundary strengthening, order strengthening, and cross-slip-induced strengthening. Cross-slip-induced strengthening was shown to be the key contributor to the high-temperature strength enhancement.
Rapid and Comprehensive Analysis of 41 Harmful Substances in Multi-Matrix Products by Gas Chromatography–Mass Spectrometry Using Matrix-Matching Calibration Strategy
Authors: Wang Yue , Xiong Dawei , He Xiangke , Yu Lihua , Li Guixiao , Wang Tian , Liu Chongshu , Liu Zhongxian , Li Zhi , Gao Cuiling
Published: May 2024

Harmful substances in consumer goods pose serious hazards to human health and the environment. However, due to the vast variety of consumer goods and the complexity of their substrates, it is difficult to simultaneously detect multiple harmful substances in different materials. This paper presents a method for the simultaneous determination of 41 harmful substances comprising 17 phthalates (PAEs), 8 organophosphate flame retardants (OPFRs), and 16 polycyclic aromatic hydrocarbons (PAHs) in five types of products using the matrix-matching calibration strategy. The method employs an efficient ultrasonic extraction procedure using a mixture of dichloromethane and methylbenzene, followed by dissolution–precipitation and analysis through gas chromatography–mass spectrometry. Compared with previous experiments, we established a universal pretreatment method suitable for multi-matrix materials to simultaneously determine multiple harmful substances. To evaluate the effects of the matrix on the experimental results, we compared neat standard solutions and matrix-matching standard solutions. The results demonstrated that all compounds were successfully separated within 30 min with excellent separation efficiency. Additionally, the linear relationships of all analytes showed strong correlation coefficients (R2) of at least 0.995, ranging from 0.02 mg/L to 20 mg/L. The average recoveries of the target compounds (spiked at three concentration levels) were between 73.6 and 124.1%, with a relative standard deviation (n = 6) varying from 1.2% to 9.9%. Finally, we tested 40 different materials from consumer products and detected 16 harmful substances in 31 samples. Overall, this method is simple and accurate, and it can be used to simultaneously determine multiple types of hazardous substances in multi-matrix materials by minimizing matrix effects, making it an invaluable tool for ensuring product safety and protecting public health.
Experimental Study on the Comparison between Network Microstructure Titanium Matrix Composites and Ti6Al4V on EDM Milling
Authors: Zhang Leheng , Hu Yizhou , Gong Sirui , Wang Zhenlong
Published: May 2024

Network microstructure titanium matrix composites (NMTMCs), featuring Ti6Al4V as the matrix and network-distributed TiB whiskers (TiBw) as reinforcement, exhibit remarkable potential for diverse applications due to their superior physical properties. Due to the difficulty in machining titanium matrix composites, electrical discharge machining (EDM) stands as one of the preferred machining techniques for NMTMCs. Nevertheless, the compromised surface quality and the recast layer significantly impact the performance of the workpiece machined by EDM. Therefore, for the purpose of enhancing the surface quality and restraining the defects of NMTMCs, this study conducted comparative EDM milling experiments between NMTMCs and Ti6Al4V to analyze the effects of discharge capacitance, charging current, and pulse interval on the surface roughness, recast layer thickness, recast layer uniformity, and surface microcrack density of both materials. The results indicated that machining energy significantly influences workpiece surface quality. Furthermore, comparative experiments exploring the influence of network reinforcement on EDM milling revealed that NMTMCs have a higher melting point, leading to an accumulation phenomenon in low-energy machining where the reinforcement could not be completely removed. The residual reinforcement in the recasting layer had an adsorption effect on molten metal affecting the thermal conductivity and uniformity within the recasting layer. Finally, specific guidelines are put forward for optimizing the material’s surface roughness, recast layer thickness, and uniformity, along with minimizing microcrack density, which attain a processing effect that features a roughness of Ra 0.9 μm, an average recast layer thickness of 6 μm with a range of 8 μm, and a surface microcrack density of 0.08 μm−1.
Photoluminescence Study of Undoped and Eu-Doped Alkali-Niobate Aluminosilicate Glasses and Glass-Ceramics
Authors: Cicconi Maria Rita , Deng Hongyi , Otsuka Takahito , Telakula Mahesh Aadhitya , Khansur Neamul Hayet , Hayakawa Tomokatsu , de Ligny Dominique
Published: May 2024

In this study, the photoluminescence (PL) behavior of two aluminosilicate glass series containing alkali-niobates ranging from 0.4 to 20 mol% was investigated. The glasses exhibit an intense visible emission centered at ~18,400 cm−1 for the peralkaline series and at higher energies (~19,300 cm−1) for the metaluminous glasses. However, the photoluminescence emission intensity varies significantly with the niobate content and the bulk chemistry. PL and fluorescence lifetime measurements indicate that the broad emission bands result from the overlap of different niobate populations, whose distribution changes with niobate content. The distinct PL behavior in the two glass series was related to the structural evolution of the niobate units upon niobium addition. An enhancement of the visible emission was observed for a higher fraction of distorted [NbO6] units. Eu-doping was carried out as a structural probe of the glass network, and also to determine if these glasses could be used as potential rare earth element (REE) activators. The crystal field strength around Eu ions is strongly dependent on the bulk chemistry and the niobate content. Furthermore, the peralkaline series showed energy transfer from the host [NbO6] to Eu3+, confirming the feasibility of exploring niobate glasses and glass-ceramics as lanthanide ion-activated luminescent materials. In addition, glass-ceramics (GCs) containing alkali-niobate phases with a perovskite-like structure were developed and studied to verify the optical performance of these materials. It was verified that the bulk chemistry influences crystallization behavior, and also the photoluminescence response. The transparent GC from the metaluminous series exhibits a quenching of the Eu3+ emission, whereas an enhanced emission intensity is observed for the peralkaline GC. The latter shows a strong excitation-dependent PL emission, suggesting energy transfer and migration of electronic excitation from one Eu population to another. Additionally, Eu3+ emissions arising from the D15 and D25 excited states were observed, highlighting the low phonon energy achievable in niobo-aluminosilicate hosts.
Early-Age Cracking of Fly Ash and GGBFS Concrete Due to Shrinkage, Creep, and Thermal Effects: A Review
Authors: Zhang Yingda , Liu Xinyue , Xu Ziyi , Yuan Weiguang , Xu Yong , Yao Zuobang , Liu Zihao , Si Ruizhe
Published: May 2024

Supplementary cementitious materials (SCMs) are eco-friendly cementitious materials that can partially replace ordinary Portland cement (OPC). The occurrence of early-age cracking in OPC-SCM blended cement is a significant factor impacting the mechanical properties and durability of the concrete. This article presents a comprehensive review of the existing research on cracking in OPC-SCM concrete mix at early ages. To assess the effects of SCMs on the early-age cracking of concrete, the properties of blended cement-based concrete, in terms of its viscoelastic behavior, evolution of mechanical performance, and factors that affect the risk of cracking in concrete at early ages, are reviewed. The use of SCMs in OPC-SCM concrete mix can be an effective method for mitigating early-age cracking while improving the properties and durability of concrete structures. Previous research showed that the shrinkage and creep of OPC-SCM concrete mix are lower than those of conventional concrete. Moreover, the lower cement content of OPC-SCM concrete mix resulted in a better resistance to thermal cracking. Proper selection, proportioning, and implementation of SCMs in concrete can help to optimize the performance and reduce the environmental impact of OPC-SCM concrete mix.
Microwave-Assisted Synthesis of Few-Layer Ti3C2Tx Loaded with Ni0.5Co0.5Se2 Nanospheres for High-Performance Supercapacitors
Authors: Wu Linghong , Shen Juan , Jin Bo
Published: May 2024

Transition metal selenides have high theoretical capacities, making them attractive candidates for energy storage applications. Here, using the microwave-absorbing properties of the materials, we designed a simple and efficient microwave-assisted synthesis method to produce a composite made of nanospheres Ni0.5Co0.5Se2 (NCSe) and highly conductive, stable Ti3C2Tx MXene. The Ni0.5Co0.5Se2/Ti3C2Tx composites are characterized via scanning electron microscopy, X-ray diffraction, cyclic voltammetry, and electrochemical impedance spectroscopy. The findings indicate that 3D Ni0.5Co0.5Se2 bimetallic selenide nanospheres were uniformly loaded within the few-layer Ti3C2Tx MXene wrapper in a short period. The optimal NCSe/Ti3C2Tx−2 electrode can demonstrate a specific capacitance of 752.4 F g–1 at 1 A g–1. Furthermore, the asymmetric supercapacitor combined with activated carbon maintains a capacitance retention of 110% even after 5000 cycles. The method of directly growing active substances on few-layer Ti3C2Tx MXene will provide inspiration for the manufacture of high-pseudocapacitance supercapacitors.
The Effect of Sintering Temperature on the Densification and Magnetic Performance of NiCuZn-Ferrites (CuO: 0–6 wt.%)
Authors: Zaspalis Stefanos , Kogias Georgios , Zaspalis Vassilios
Published: May 2024

This article reported on the effect of Cu-content and sintering temperature on the magnetic permeability and power losses of monolithic iron-deficient NiCuZn-ferrite components with low Cu-contents aimed to be used for power applications at frequencies up to 1 MHz. In particular NiαZnb1−xCuxFe1.9O4 ferrite compositions are investigated with a constant Ni/Zn atomic ratio a/b = 0.9 and 0 < x < 0.017. As found, the addition of Cu enables the achievement of good magnetic performance at lower sintering temperatures and, therefore, lower production cost. At all Cu-contents, the initial permeability as a function of the sintering temperature passes through a maximum above which structural deterioration due to asymmetric grain growth occurs. The temperature at which this maximum permeability occurs depends on the Cu content and coincides with the achievement of the maximum density of 5.1–5.2 g cm−3 (relative density ~97%). At Cu-contents x = 0.006–0.012 and sintering temperatures 1200–1100 °C power losses (tan(δ)/μ at 1 MHz, 25 °C) οf 50 × 10−6 could be achieved and initial permeabilities (10 kHz, 0.1 mT, 25 °C) of around 400 with very good frequency and temperature stability. At CuO content higher than 4 wt.% (i.e., x > 0.012) and sintering temperatures higher than 1150 °C, pronounced microstructural disturbances due to asymmetric grain growth result in low permeabilities and high losses. It is suggested that at low CuO contents and low sintering temperatures, the densification enhancement may not proceed through Cu-rich phase segregation but through the creation of oxygen vacancies.
One-Year Evaluation of High-Power Rapid Curing on Dentin Bond Strength
Authors: Klarić Eva , Bosnić Josipa Vukelja , Par Matej , Tarle Zrinka , Marovic Danijela
Published: May 2024

This study investigated the effect of 3 s light-curing with a high-power LED curing unit on the shear bond strength of bulk-fill composites. Four bulk-fill composites were bonded to dentin with a universal adhesive (Scotchbond Universal Plus): two materials designed for rapid curing (Tetric PowerFill and Tetric PowerFlow) and two controls (Filtek One Bulk Fill Restorative and SDR Plus Bulk Fill Flowable). The 4 mm composite layer was light-cured with Bluephase PowerCure for 20 s at 1000 mW/cm2 (“20 s”) or for 3 s at 3000 mW/cm2 (“3 s”). The samples were stored at 37 °C in distilled water and tested after 1, 6 and 12 months. The samples polymerised in the “3 s” mode had statistically similar or higher bond strength than the samples cured in “20 s” mode, except for the Tetric PowerFlow (1 month) and SDR+ (6 month). The flowable materials Tetric PowerFlow and SDR Plus initially showed the highest values in the “3 s” and “20 s” groups, which decreased after 12 months. The bond strength was statistically similar for all materials and curing protocols after 12 months, except for Tetric PowerFill cured with the “3 s” protocol (21.22 ± 5.0 MPa), which showed the highest value. Tetric PowerFill showed the highest long-term bond strength. While “3 s” curing resulted in equal or better shear bond strength, its use can only be recommended for a material with an AFCT agent such as Tetric PowerFill.
Nickel–Cobalt Bimetal Hierarchical Hollow Nanosheets for Efficient Oxygen Evolution in Seawater
Authors: An Rongzheng , Li Guoling , Liu Zhiliang
Published: May 2024

The electrochemical splitting of seawater is promising but also challenging for sustainable hydrogen gas production. Herein, ZIF-67 nanosheets are grown on nickel foam and then etched by Ni2+ in situ to obtain a hierarchical hollow nanosheets structure, which demonstrates outstanding OER performance in alkaline seawater (355 mV at 100 mA cm−2). Diven by a silicon solar panel, an overall electrolysis energy efficiency of 62% is achieved at a high current of 100 mA cm−2 in seawater electrolytes. This work provides a new design route for improving the catalytic activity of metal organic framework materials.
Enhancing the Mechanical Properties and Water Permeability of Pervious Planting Concrete: A Study on Additives and Plant Growth
Authors: He Juan , Xu Shanhansu , Sang Guochen , Wu Yonghua , Liu Shuang
Published: May 2024

Pervious planting concrete (PPC) is in line with the concept of ecological environmental protection. However, due to its own porous structure, it is difficult to obtain excellent mechanical properties and water permeability at the same time, which hinders its promotion and application. In this paper, natural gravel (NG), ordinary Portland cement (OPC), polyvinyl alcohol latex powder (PVAP) and polycarboxylate superplasticizer (PS) were used to prepare the PPC, and its mechanical properties and water permeability were studied. Three kinds of plants were planted in the PPC and their planting properties were studied. At the same time, the effect of Bacillus on the planting properties was studied. The results show that when the water–binder ratio (W/B) was 0.28 and the PVAP content was 0.8%, both the mechanical properties and water permeability of the PPC were optimal. The compressive strength and permeability coefficient were 14.2 MPa and 14.48 mm/s, respectively. The mechanical properties and water permeability of PPC prepared with 10~20 mm NG were better than those prepared with 5~10 mm NG. Among the three plants, the germination rate and growth of Elymus dahuricus Turcz (EDT) were the best. The incorporation of Bacillus can optimize its planting properties and promote the effective combination between plants and the PPC substrate.
Plant Waste-Based Bioadditive as an Antioxidant Agent and Rheological Modifier of Bitumen
Authors: Loise Valeria , Abe Abraham A. , Porto Michele , Muzzalupo Innocenzo , Madeo Luigi , Colella Maria Francesca , Rossi Cesare Oliviero , Caputo Paolino
Published: May 2024

In recent times, circular economy initiatives in addition to the need for sustainable biomaterials have brought about several attempts at the eco-friendly, eco-sustainable and cost-effective production of asphalt pavements. It is an increasingly common practice in the asphalt industry to improve road pavement performance using additives to enhance the physico-chemical properties of bitumen, which performs the role of the binder in the asphalt mix. This paper evaluated the potential of a bio-based additive derived from olive leaf residue as a modifier and antioxidant agent for bitumen. Samples of neat, aged and doped aged bitumen were analyzed. In this study, the two bio-based additives were characterized in terms of phenol, chlorophyll, lignin and cellulose content, which was correlated with the mechanical properties of the tested samples. The mechanical properties of the neat, modified, aged and unaged samples were evaluated via Dynamic Shear Rheology. The bio-based additives proved to be promising and can improve the properties of bitumen binder and the performance of asphalt pavements in general.