bluuebunny/crossref_metadata_2025 huggingface dataset:
Low Concentrations of Gold Nanoparticles as Electric Charge Carriers in Piezoelectric Cement-Based Materials
Authors: Triana-Camacho Daniel A. , Mendoza Reales Oscar A. , Quintero-Orozco Jorge H.
Published: January 2024

Piezoelectric cement-based composites could serve to monitor the strain state of structural elements or act as self-powered materials in structural health monitoring (SHM) applications. The incorporation of piezoelectric materials as an active phase within cement matrices has presented a highly attractive avenue until today. However, their application is challenged by the low electrical conductivity of the hydrated cement matrix. Gold nanoparticles (Au NPs) possess substantial potential for elevating the free electrical charge within the matrix, increasing its electrical conductivity between the Au NPs and the cement matrix, thereby enhancing the piezoelectric response of the composite. In this sense, the objective of this study is to investigate the effects of incorporating low concentrations of gold nanoparticles (Au NPs) (442 and 658 ppm) on the electrical and piezoelectric properties of cement-based composites. Additionally, this study considers the effects of such properties when the material is cured under a constant electric field. Electrical impedance spectroscopy was used to evaluate the polarization resistance and piezoresistive properties of the material. Additionally, open-circuit potential measurements were taken alongside the application of mechanical loads to assess the piezoelectric activity of the composites. The findings revealed a notable decrease in the composite’s total electrical resistance, reaching a value of 1.5 ± 0.2 kΩ, almost four times lower than the reference specimens. In the realm of piezoelectricity, the piezoelectric voltage parameter g33 exhibited a remarkable advancement, improving by a factor of 57 when compared to reference specimens. This significant enhancement can be attributed to both the concentration of Au NPs and the electrical curing process. In summary, the outcomes of this study underscore the feasibility of creating a highly electrically conductive cement-based matrix, using low concentrations of gold nanoparticles as electric charge carries, and indicate the possible piezoelectric behavior of the studied compposite.
The Use of Solid Sodium Silicate as Activator for an Amorphous Wollastonitic Hydraulic Binder
Authors: Antunes Mónica , Santos Rodrigo Lino , Pereira João , Horta Ricardo Bayão , Colaço Rogério
Published: January 2024

To ensure the acceptable mechanical strength of amorphous wollastonitic hydraulic binders (AWHs), activation with a sodium silicate solution is necessary. However, the use of this type of activator increases the final cost and the complexity of the product’s overall use. In this work, we focus on enhancing the manufacturing of the alkaline activator by producing three Na2SiO3 powders using cost-effective raw materials. The procedure consisted of heating a mixture of NaOH pebbles with either sand, glass, or diatomite to a temperature of 330 °C for 2 h. After synthesis, the powders were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD) techniques. Finally, mortars made with AWHs were activated using the synthesized powders that were added either as a solid or dissolved in an aqueous solution. The compressive strength results in these mortars show that the lab-made activators are competitive with the traditional sodium silicate activators. Furthermore, the synthetized activators can be added in either solid form or pre-dissolved in a solution. This innovative approach represents a more economical, sustainable and easy-to-use approach to enhancing the competitiveness of AWHs.
Demonstration of 10 nm Ferroelectric Al0.7Sc0.3N-Based Capacitors for Enabling Selector-Free Memory Array
Authors: Chen Li , Liu Chen , Lee Hock Koon , Varghese Binni , Ip Ronald Wing Fai , Li Minghua , Quek Zhan Jiang , Hong Yan , Wang Weijie , Song Wendong , Lin Huamao , Zhu Yao
Published: January 2024

In this work, 10 nm scandium-doped aluminum nitride (AlScN) capacitors are demonstrated for the construction of the selector-free memory array application. The 10 nm Al0.7Sc0.3N film deposited on an 8-inch silicon wafer with sputtering technology exhibits a large remnant polarization exceeding 100 µC/cm2 and a tight distribution of the coercive field, which is characterized by the positive-up-negative-down (PUND) method. As a result, the devices with lateral dimension of only 1.5 μm show a large memory window of over 250% and a low power consumption of ~40 pJ while maintaining a low disturbance rate of <2%. Additionally, the devices demonstrate stable multistate memory characteristics with a dedicated operation scheme. The back-end-of-line (BEOL)-compatible fabrication process, along with all these device performances, shows the potential of AlScN-based capacitors for the implementation of the high-density selector-free memory array.
Experimental Study on Liquid Metal Embrittlement of Al-Zn-Mg Aluminum Alloy (7075): From Macromechanical Property Experiment to Microscopic Characterization
Authors: Zhang Daixin , Cai Kaikai , Zheng Jian , Feng Haiyun , Song Pu , Hu Hongwei , Mao Zhiyuan
Published: January 2024

This study is a multiscale experimental investigation into the embrittlement of Al-Zn-Mg aluminum alloy (7075-T6) caused by liquid metal gallium. The results of the experiment demonstrate that the tensile strength of the 7075-T6 aluminum alloy significantly weakens with an increase in the embrittlement temperature and a prolonged embrittlement time, whereas it improves with an increase in the strain rate. On the basis of the analysis of the experimental data, the sensitivity of the embrittlement of 7075-T6 aluminum alloy by liquid gallium to the loading strain rate is significantly higher compared to other environmental factors. In addition, this study also includes several experiments for microscopic observation, such as Scanning Electron Microscope (SEM) observation, Energy-Dispersive Spectrometer (EDS) spectroscopy, and Electron Back Scatter Diffraction (EBSD) analysis. The experimental observations confirmed the following: (1) gallium is enriched in the intergranular space of aluminum; (2) the fracture mode of 7075-T6 aluminum alloy changes from ductile to brittle fracture; and (3) the infiltration of liquid gallium into aluminum alloys and its enrichment in the intergranular space result in the formation of new dislocation nucleation sites, in addition to the original dislocations cutting and entanglement. This reduces the material’s ability to undergo plastic deformation, intensifies stress concentration at the dislocation nucleation point, and, ultimately, leads to the evolution of dislocations into cracks.
The Preparation and Properties of Ti(Nb)-Si-C Coating on the Pre-Oxidized Ferritic Stainless Steel for Solid Oxide Fuel Cell Interconnect
Authors: Li Xichao , Chi Yongchen , Wei Shouli , Sun Xianwei , Zhao Jingxiang , Hou Qiangqiang , Fu Kang , Dai Zuoqiang , Zheng Lili
Published: January 2024

Cr2O3 scale growth and volatilization are the main cause of the performance degradation of solid oxide fuel cells (SOFCs) with an Fe-based ferritic stainless steel (FSS) interconnect. In this work, an amorphous Ti(Nb)-Si-C coating is prepared on the pre-oxidized SUS430 with D.C. magnetron sputtering as the protective coating. The amorphous Ti(Nb)-Si-C coated alloy exhibits significantly enhanced oxidation resistance, and the oxidation kinetics obey the parabolic law with a low parabolic rate of 9.36 × 10−15 g2·cm−4·s−1. A dual-layer oxide scale is formed composed of an inner layer rich in Cr2O3 and an outer layer rich in rutile TiO2 and amorphous SiO2. MnCr2O4 appears at the interface between the inner and outer oxide layers. Meanwhile, the amorphous Ti(Nb)-Si-C coating also effectively blocks the outward diffusion of Cr. In addition, the coated steel presents good electrical properties with an area-specific resistance (ASR) of 13.57 mΩ·cm2 at 800 °C after oxidation at 800 °C in air for 500 h.
Internal Adaptation of Composite Fillings Made Using Universal Adhesives—A Micro-Computed Tomography Analysis
Authors: Kaczor-Wiankowska Kinga , Puszkarz Adam K. , Palczewska-Komsa Mirona , Lipa Sebastian , Krasowski Michał , Sokołowski Jerzy , Lewusz-Butkiewicz Katarzyna , Ulacha Katarzyna , Nowicka Alicja
Published: January 2024

This study aimed to evaluate internal tooth–filling interfaces of composite fillings made using universal adhesives using micro-computed tomography (µCT). Sixty class V cavities were randomly assigned into six groups: Peak Universal etch and rinse (PER), Peak Universal self-etch (PSE), Adhese Universal etch and rinse (AER), and Adhese Universal self-etch (ASE). Two further adhesives considered gold standards were used as control groups: OptiBond FL (OER) for the etch and rinse technique and Clearfil SE for the self-etch technique (CSE). All teeth were subjected to thermomechanical loading and four-year water storage. Next, they were analyzed using µCT to investigate the internal tooth–filling interfaces. The proportions between the gap volume (GV) at the tooth–filling interface and the volume of applied composite filling (FV), between the gap and cavity volumes (CV), and between the gap volumes at the tooth–filling interface of the external (EGV) and internal (IGV) parts were calculated. Adhese Universal achieved the significantly lowest gap-to-filling- and gap-to-cavity-volume ratios for both types of etching techniques comparing to those of the Peak Universal and control groups. Significant differences between the gaps in external and internal parts of the tooth–filling interface were only noted in the control groups. Internal gap formation and development at the tooth–filling interface depend on the material as well as the type of its application.
The Effect of Doping on the Electrical and Dielectric Properties of Hydroxyapatite for Medical Applications: From Powders to Thin Films
Authors: Duta Liviu , Grumezescu Valentina
Published: January 2024

Recently, the favorable electrical properties of biomaterials have been acknowledged as crucial for various medical applications, including both bone healing and growth processes. This review will specifically concentrate on calcium phosphate (CaP)-based bioceramics, with a notable emphasis on hydroxyapatite (HA), among the diverse range of synthetic biomaterials. HA is currently the subject of extensive research in the medical field, particularly in dentistry and orthopedics. The existing literature encompasses numerous studies exploring the physical–chemical, mechanical, and biological properties of HA-based materials produced in various forms (i.e., powders, pellets, and/or thin films) using various physical and chemical vapor deposition techniques. In comparison, there is a relative scarcity of research on the electrical and dielectric properties of HA, which have been demonstrated to be essential for understanding dipole polarization and surface charge. It is noteworthy that these electrical and dielectric properties also offer valuable insights into the structure and functioning of biological tissues and cells. In this respect, electrical impedance studies on living tissues have been performed to assess the condition of cell membranes and estimate cell shape and size. The need to fill the gap and correlate the physical–chemical, mechanical, and biological characteristics with the electrical and dielectric properties could represent a step forward in providing new avenues for the development of the next-generation of high-performance HA-doped biomaterials for future top medical applications. Therefore, this review focuses on the electrical and dielectric properties of HA-based biomaterials, covering a range from powders and pellets to thin films, with a particular emphasis on the impact of the various dopants used. Therefore, it will be revealed that each dopant possesses unique properties capable of enhancing the overall characteristics of the produced structures. Considering that the electrical and dielectric properties of HA-based biomaterials have not been extensively explored thus far, the aim of this review is to compile and thoroughly discuss the latest research findings in the field, with special attention given to biomedical applications.
Investigation on Creep Deformation and Age Strengthening Behavior of 304 Stainless Steel under High Stress Levels
Authors: Zhan Lihua , Xie Hao , Yang Youliang , Zhao Shuai , Chang Zhilong , Xia Yunni , Zheng Zeyu , Zhou Yujie
Published: January 2024

The creep deformation behavior and age strengthening behavior of 304 stainless steel under high stress levels were systematically studied by uniaxial creep test, tensile test, XRD diffraction test and transmission electron microscopy. The results show that the total creep strain and the initial creep strain rate increase with the increase in stress level, and the creep strain in the whole aging process is mainly produced in the initial creep stage. The calculated stress exponent shows that the main mechanism of creep deformation of 304 stainless steel at 453 K is dislocation slip. The strength and plasticity of 304 stainless steel after creep aging are improved simultaneously. Microstructural observations indicate an increase in dislocation density and martensite content, as well as austenite and twins, leading to an improvement in strength and plasticity, respectively. In addition, considering the influence of dislocation density on creep behavior, the relative dislocation density increase is introduced into the hyperbolic sine creep model, and a simple mechanism-based creep aging constitutive model is established. The creep strain predicted by the model is in good agreement with the experimental data of 304 stainless steel. The findings can provide theoretical support for the application of creep age forming in 304 stainless steel parts.
Optimizing the Mechanical Properties of Cement Composite Boards Reinforced with Cellulose Pulp and Bamboo Fibers for Building Applications in Low-Cost Housing Estates
Authors: Taiwo Anuoluwapo S. , Ayre David S. , Khorami Morteza , Rahatekar Sameer S.
Published: January 2024

Africa is the third-richest continent in the world in terms of bamboo species. Despite these laudable natural resources, most African countries still use asbestos cement board as one of their major building materials. This is chiefly due to the high cost of equipment and technologies associated with non-asbestos-fiber cement board production. The current research seeks to underscore the possibility of utilizing these massive continent resources for non-asbestos-fiber cement board production by employing the existing production process in the asbestos cement industries via an innovatively developed laboratory-simulated Hatschek process. Non-asbestos-fiber cement boards incorporating kraft and bamboo fibers were successfully produced in the laboratory using this innovative method based on Hatschek technology, with natural fibre addition in the range of 2–6 wt.%. Experimental results revealed that the Flexural strength and deflection of the board improved significantly, producing optimum values of 10.41 MPa and 2.0 mm, respectively for composite board reinforced with 10 wt.% and 6 wt.% of kraft pulp and bamboo fibers, respectively. The SEM morphology of the fractured surfaces revealed the mode of composite fracture as well as good interaction at the fiber–matrix interface. Overall, the mechanical properties of the developed composite boards satisfy the minimum requirements of relevant standards based on fiber cement flat sheets and can be employed for internal building applications in low-cost housing estates in developing countries. The outcome of this research indicates that the current industrial production process based on Hatschek technology can be employed for non-asbestos-fiber cement board production using the studied natural fiber.
Advanced Ceramics with Dual Functions of Healing and Decomposition
Authors: Sekine Nobuhide , Nakajima Yasushi , Kamo Takahiro , Ito Masahiro , Nakao Wataru
Published: January 2024

This study developed advanced ceramic materials with both healing and decomposition functions using a metastable product generated under superheated steam. The developed composite material comprises ZrC particles dispersed in a yttria-stabilized zirconia (YSZ) matrix. After introducing a surface crack of approximately 120 μm on the composite specimen, it showed a complete strength recovery rate after one hour of heat treatment under superheated steam at 400 °C, while it exhibited a decomposition behavior after one hour of heat treatment in air at 400 °C. The XRD analysis of the heat-treated specimens showed that the final product was monoclinic ZrO2 under both steam and air conditions. In other words, full strength recovery in superheated steam was achieved by a chain reaction involving metastable intermediate products derived from H2O, unlike the reaction in air.
Effect of Nb-Ti Microalloyed Steel Precipitation Behavior on Hot Rolling Strip Shape and FEM Simulation
Authors: Li Kaisheng , Shao Jian , Yao Chihuan , Jia Pan , Xie Shuhao , Chen Desheng , Xiao Min
Published: January 2024

Strip shape control is a hotspot and challenge in strip rolling, where the development trend of rolling technology is towards high strength, high toughness, and a large width-to-thickness ratio. The influence of material microstructure evolution on strip shape control is being increasingly emphasized. In this paper, a Nb-Ti microalloyed steel is taken as the research object. Thermodynamic and kinetic models focusing on the precipitation of the austenite phase are established to quantify the precipitation process. A coupled model of rolls and strips is built using ABAQUS 2022 software, where the precipitation strengthening model and high-temperature constitutive model are embedded into the finite element model (FEM) through subroutines. A two-dimensional alternating differential model is employed to acquire real-time temperature differences in the width direction of the strip. The effects of precipitation inclusion and exclusion on the strip crown under different operating conditions are compared and analyzed. The results indicate that as the temperature decreases, the strengthening effect increases, reaching around 40 MPa at temperatures above 1000 °C and 96.6 MPa at 800 °C. Furthermore, the inclusion of crown in the precipitation consideration is more sensitive to overall temperature changes, but as the strip width decreases, the sensitivity of crown to temperature decreases. The research findings of this paper provide guidance for improving strip shape control and reducing abnormalities during the rolling process.
Mesoporous Silica MCM-41 from Fly Ash as a Support of Bimetallic Cu/Mn Catalysts for Toluene Combustion
Authors: Mokrzycki Jakub , Fedyna Monika , Duraczyńska Dorota , Marzec Mateusz , Panek Rafał , Franus Wojciech , Bajda Tomasz , Karcz Robert
Published: January 2024

The main outcome of this research was to demonstrate the opportunity to obtain a stable and well-ordered structure of MCM-41 synthesized from fly ash. A series of bimetallic (Cu/Mn) catalysts supported at MCM-41 were prepared via grinding method and investigated in catalytic toluene combustion reaction to show the material’s potential application. It was proved, that the Cu/Mn ratio had a crucial effect on the catalytic activity of prepared materials. The best catalytic performance was achieved with sample Cu/Mn(2.5/2.5), for which the temperature of 50% toluene conversion was found to be 300 °C. This value remains in line with the literature reports, for which comparable catalytic activity was attained for 3-fold higher metal loadings. Time-on-stream experiment proved the thermal stability of the investigated catalyst Cu/Mn(2.5/2.5). The obtained results bring a valuable background in the field of fly ash utilization, where fly ash-derived MCM-41 can be considered as efficient and stable support for dispersion of active phase for catalyst preparation.
Corrosion Behavior of As-Cast and Heat-Treated Al–Co Alloys in 3.5 wt% NaCl
Authors: Sfikas Athanasios K. , Lekatou Angeliki G. , Emmanouilidou Sevasti , Tsirka Kyriaki
Published: January 2024

The present work evaluates the effect of Co content on the microstructure and corrosion performance of Al–Co alloys of various compositions (2–32 wt% Co), fabricated by flux-assisted stir casting. A preliminary investigation on the effect of heat treatment (600 °C, up to 72 h) on the microstructure and corrosion behavior of Al–20 wt% Co and Al–32 wt% Co was also conducted. The Al– (2–10) wt% Co alloys were composed of acicular Al9Co2 particles uniformly dispersed in an Al matrix. The Al–20 wt% Co and Al–32 wt% Co alloys additionally contained Al13Co4 blades enveloped in Al9Co2 wedges. Heat treatment of Al–20 wt% Co and Al–32 wt% Co led to a significant reduction in the volume fraction of Al13Co4 and a decrease in hardness. Al–Co alloys with high Co content (10–32 wt% Co) exhibited greater resistance to localized corrosion in 3.5 wt% NaCl, but lower resistance to general corrosion compared to the (0–5 wt% Co) alloys. Heat treatment led to a slight increase in the corrosion resistance of the Al–Co alloys. The microstructure of the produced alloys was analyzed and correlated with the corrosion performance. Finally, corrosion mechanisms were formulated.
Microstructure and Mechanical Properties of Al–Li Alloys with Different Li Contents Prepared by Selective Laser Melting
Authors: Shao Shuobing , Liang Zhuoheng , Yin Peng , Li Xinyuan , Zhang Yongzhong
Published: January 2024

Research on the development of new lightweight Al–Li alloys using a selective laser melting process has great potential for industrial applications. This paper reports on the development of novel aluminum–lithium alloys using selective laser melting technology. Al–Cu–Li–Mg–Ag–Sc–Zr pre-alloyed powders with lithium contents of 1 wt.%, 2 wt.% and 3 wt.%, respectively, were prepared by inert gas atomization. After SLM process optimization, the microstructure and mechanical properties of the as-printed specimens were investigated. The densifications of the three newly developed alloys were 99.51%, 98.96% and 92.01%, respectively. They all had good formability, with the lithium loss rate at about 15%. The as-printed alloy with 1% Li content presented good comprehensive properties, with a yield strength of 413 ± 16 MPa, an ultimate tensile strength of 461 ± 12 MPa, and an elongation of 14 ± 1%. The three alloys exhibited a layered molten pool stacking morphology and had a typical heterostructure. The columnar crystals and equiaxed fine grains were alternately arranged, and most of the precipitated phases were enriched at the grain boundaries. The change in Li content mainly affected the precipitation of the Cu-containing phase. When the Li content was 1 wt.%, the following occured: θ phase, T1 phase and TB phase. When Li increased to 2 wt.%, T1 and T2 phases precipitated together. When Li reaches 3 wt.%, δ’ phase precipitated with T2 phase. This study provides useful guidance for the future SLM forming of new crack-free and high-strength Al–Li alloys.
Microhardness and Microstructure Analysis of the LPBF Additively Manufactured 18Ni300
Authors: Cerezo Pablo M. , Aguilera Jose A. , Garcia-Gonzalez Antonio , Lopez-Crespo Pablo
Published: January 2024

This research focuses on analysing the 18Ni300 maraging steel produced through laser powder bed fusion. Specifically, it aims to examine the phase components using X-ray diffraction, the microstructure through scanning electron microscopy, and the hardness of the different structures present in the manufactured material. The primary goal is to meticulously analyse the material and its microstructures. By doing so, a correlation between the hardness and each structure type, be it cellular or columnar, can be established. This will allow us to pinpoint any defects in the material before any surface chemical treatment is carried out and facilitate a thorough examination of its microstructure. A consistent pattern emerges across the samples through systematic measurement of microhardness distribution in various locations and detailed examination of the structure. The findings of the study reveal that the hardness of cellular and columnar structures exhibits a significant variation based on the location of the measurement about cell boundaries. The hardness value is notably higher in the combination of cellular and multiple layers, as the data indicate.
Effects of Polybutylene Succinate Content on the Rheological Properties of Polylactic Acid/Polybutylene Succinate Blends and the Characteristics of Their Fibers
Authors: Choi Ik Sung , Kim Young Kwang , Hong Seong Hui , Seo Hye-Jin , Hwang Sung-Ho , Kim Jongwon , Lim Sang Kyoo
Published: January 2024

Polylactic acid (PLA) and polybutylene succinate (PBS) are gaining prominence as environmentally friendly alternatives to petroleum-based polymers due to their inherent biodegradability. For their textile applications, this research is focused on exploring the effects of PBS content on the rheological properties of PLA/PBS blends and the characteristics of PLA/PBS blend fibers. PLA/PBS blends and fibers with varying PBS contents (0 to 10 wt.%) were prepared using melt-blending and spinning methods. Uniform morphologies of the PLA/PBS blends indicated that PBS was compatible with PLA, except at 10% PBS content, where phase separation occurred. The introduction of PBS reduced the complex viscosity of the blends, influencing fiber properties. Notably, PLA/PBS fibers with 7% PBS exhibited improved crystallinity, orientation factor, and elasticity (~16.58%), with a similar tensile strength to PLA fiber (~3.58 MPa). The results suggest that an optimal amount of PBS enhances alignment along the drawing direction and improves the molecular motion in PLA/PBS blend fiber. This study highlights the potential of strategically blending PBS to improve PLA fiber characteristics, promising advancement in textile applications.
Alkaline Activation of Binders: A Comparative Study
Authors: Alves Bianca Ignacio Almeida , Marvila Markssuel Teixeira , Linhares Júnior José Alexandre Tostes , Vieira Carlos Maurício Fontes , Alexandre Jonas , de Azevedo Afonso Rangel Garcez
Published: January 2024

Binders formulated with activated alkali materials to replace Portland cement, which has high polluting potential due to CO2 emissions in its manufacture, have increasingly been developed. The objective of this study is to evaluate the main properties of activated alkali materials (AAM) produced by blast furnace slag, fly ash, and metakaolin. Initially, binders were characterized by their chemical, mineralogical and granulometric composition. Later, specimens were produced, with molarity variation between 4.00 and 5.50, using the binders involved in the research. In preparing the activating solution, sodium hydroxide and silicate were used. The evaluated properties of AAM were consistency, viscosity, water absorption, density, compressive strength (7 days of cure), calorimetry, mineralogical analysis by X-ray diffraction, and morphological analysis by scanning electron microscopy. The results of evaluation in the fresh state demonstrate that metakaolin has the lowest workability indices of the studied AAM. The results observed in the hardened state indicate that the metakaolin activation process is optimized with normal cure and molarity of 4.0 and 4.5 mol/L, obtaining compressive strength results after 7 days of curing of approximately 30 MPa. The fly ash activation process is the least intense among the evaluated binders. This can be seen from the absence of phases formed in the XRD in the compositions containing fly ash as binder. Unlike blast furnace slag and metakaolin, the formation of sodalite, faujasite or tobermorite is not observed. Finally, the blast furnace slag displays more intense reactivity during thermal curing, obtaining compressive strength results after 7 days of curing of around 25 MPa. This is because the material’s reaction kinetics are low but can be increased in an alkaline environment, and by the effect of temperature. From these results, it is concluded that each precursor has its own activation mechanism, observed by the techniques used in this research. From the results obtained in this study, it is expected that the alkaline activation process of the types of binders evaluated herein will become a viable alternative for replacing Portland cement, thus contributing to cement technology and other cementitious materials.
Dynamic Mechanical Properties and Modified Johnson-Cook Model Considering Recrystallization Softening for Nickel-Based Powder Metallurgy Superalloys
Authors: Ling Chen , Ren Xiaoping , Wang Xuepeng , Li Yinghao , Liu Zhanqiang , Wang Bing , Zhao Jinfu
Published: January 2024

The material undergoes high temperature and high strain rate deformation process during the cutting process, which may induce the dynamic recrystallization behavior and result in the evolution of dynamic mechanical properties of the material to be machined. In this paper, the modified Johnson-Cook (J-C) model for nickel-based powder metallurgy superalloy considering dynamic recrystallization behavior in high strain rate and temperature is proposed. The dynamic mechanical properties of the material under different strain rates and temperature conditions are obtained by quasi-static compression test and split Hopkinson pressure bar (SHPB) test. The coefficients of the modified J-C model are obtained by the linear regression method. The modified model is verified by comparison with experimental and model prediction results. The results show that the modified J-C model proposed in this paper can accurately describe the mechanical properties of nickel-based powder metallurgy superalloys at high temperatures and high strain rates. This provides help for studying the cutting mechanism and finite element simulation of nickel-based powder metallurgy superalloy.
Green- and Blue-Emitting Tb3+-Activated Linde Type A Zeolite-Derived Boro-Aluminosilicate Glass for Deep UV Detection/Imaging
Authors: Xiao Yongneng , Hou Shaoyi , Yang Zhenhuai , Huang Xingxing , Guo Yuanjun , Ji Siyu , Huang Xiaochan , Wang Fengshuang , Hu Qiang , Guo Xiaodong
Published: January 2024

Tb3+-activated LTA zeolite-derived boro-aluminosilicate glass samples with a composition of xTb2O3-68(Na2O-Al2O3-SiO2)–32B2O3 (x = 0.2, 1.0 and 10 extra wt%) were prepared using the melt-quenching method. The emission spectra recorded upon ultraviolet (UV) excitation with two different wavelengths of 193 and 378 nm showed blue light (5D3 to 7FJ=6,5,4 and 5D4 to 7F6 transitions of Tb3+) and green light (5D4 to 7F5 transition of Tb3+) emissions with comparable intensities up to a Tb3+ concentration of 10 extra wt%. Of note, the mean decay times of the green luminescence of the glass samples were relatively fast (<20 μs). The synthesized glass has potential in applications concerning UV imaging, UV detection, and plasma display panels.
Lipidome Plasticity Enables Unusual Photosynthetic Flexibility in Arctic vs. Temperate Diatoms
Authors: Svenning Jon Brage , Vasskog Terje , Campbell Karley , Bæverud Agnethe Hansen , Myhre Torbjørn Norberg , Dalheim Lars , Forgereau Zoé Lulu , Osanen Janina Emilia , Hansen Espen Holst , Bernstein Hans C.
Published: January 2024

The diatom lipidome actively regulates photosynthesis and displays a high degree of plasticity in response to a light environment, either directly as structural modifications of thylakoid membranes and protein–pigment complexes, or indirectly via photoprotection mechanisms that dissipate excess light energy. This acclimation is crucial to maintaining primary production in marine systems, particularly in polar environments, due to the large temporal variations in both the intensity and wavelength distributions of downwelling solar irradiance. This study investigated the hypothesis that Arctic marine diatoms uniquely modify their lipidome, including their concentration and type of pigments, in response to wavelength-specific light quality in their environment. We postulate that Arctic-adapted diatoms can adapt to regulate their lipidome to maintain growth in response to the extreme variability in photosynthetically active radiation. This was tested by comparing the untargeted lipidomic profiles, pigmentation, specific growth rates and carbon assimilation of the Arctic diatom Porosira glacialis vs. the temperate species Coscinodiscus radiatus during exponential growth under red, blue and white light. Here, we found that the chromatic wavelength influenced lipidome remodeling and growth in each strain, with P. glacialis showing effective utilization of red light coupled with increased inclusion of primary light-harvesting pigments and polar lipid classes. These results indicate a unique photoadaptation strategy that enables Arctic diatoms like P. glacialis to capitalize on a wide chromatic growth range and demonstrates the importance of active lipid regulation in the Arctic light environment.
Purification and Properties of a Plasmin-like Marine Protease from Clamworm (Perinereis aibuhitensis)
Authors: Jiang Tingting , Zhang Bing , Zhang Haixing , Wei Mingjun , Su Yue , Song Tuo , Ye Shijia , Zhu Yuping , Wu Wenhui
Published: January 2024

Marine organisms are a rich source of enzymes that exhibit excellent biological activity and a wide range of applications. However, there has been limited research on the proteases found in marine mudflat organisms. Based on this background, the marine fibrinolytic enzyme FELP, which was isolated and purified from clamworm (Perinereis aibuhitensis), has exhibited excellent fibrinolytic activity. We demonstrated the FELP with a purification of 10.61-fold by precipitation with ammonium sulfate, ion-exchange chromatography, and gel-filtration chromatography. SDS-PAGE, fibrin plate method, and LC–MS/MS indicated that the molecular weight of FELP is 28.9 kDa and identified FELP as a fibrinolytic enzyme-like protease. FELP displayed the maximum fibrinolytic activity at pH 9 (407 ± 16 mm2) and 50 °C (724 ± 27 mm2) and had excellent stability at pH 7–11 (50%) or 30–60 °C (60%), respectively. The three-dimensional structure of some amino acid residues of FELP was predicted with the SWISS-MODEL. The fibrinolytic and fibrinogenolytic assays showed that the enzyme possessed direct fibrinolytic activity and indirect fibrinolysis via the activation of plasminogen; it could preferentially degrade Aα-chains of fibrinogen, followed by Bβ- and γ-chains. Overall, the fibrinolytic enzyme was successfully purified from Perinereis aibuhitensis, a marine Annelida (phylum), with favorable stability that has strong fibrinolysis activity in vitro. Therefore, FELP appears to be a potent fibrinolytic enzyme with an application that deserves further investigation.
Venomics Reveals the Venom Complexity of Sea Anemone Heteractis magnifica
Authors: Li Ming , Mao Kailin , Huang Meiling , Liao Yanling , Fu Jinxing , Pan Kun , Shi Qiong , Gao Bingmiao
Published: January 2024

The venoms of various sea anemones are rich in diverse toxins, which usually play a dual role in capturing prey and deterring predators. However, the complex components of such venoms have not been well known yet. Here, venomics of integrating transcriptomic and proteomic technologies was applied for the first time to identify putative protein and peptide toxins from different tissues of the representative sea anemone, Heteractis magnifica. The transcriptomic analysis of H. magnifica identified 728 putative toxin sequences, including 442 and 381 from the tentacles and the column, respectively, and they were assigned to 68 gene superfamilies. The proteomic analysis confirmed 101 protein and peptide toxins in the venom, including 91 in the tentacles and 39 in the column. The integrated venomics also confirmed that some toxins such as the ShK-like peptides and defensins are co-expressed in both the tentacles and the column. Meanwhile, a homology analysis was conducted to predict the three-dimensional structures and potential activity of seven representative toxins. Altogether, this venomics study revealed the venom complexity of H. magnifica, which will help deepen our understanding of cnidarian toxins, thereby supporting the in-depth development of valuable marine drugs.
Numerical Simulation of Squeeze-Casting SiC3D/Al Ceramic Matrix Composites
Authors: Wang Yangwei , Zhang Fangzhou , Feng Sijia , Bao Jiawei , Gong Yanni , Yuan Chunyuan , Zhao Denghui
Published: January 2024

In this study, the filling and solidification processes of squeeze-casting SiC3D/Al composites were analyzed by the ProCAST simulation software (ver. 2018.0). A practical squeeze-casting experiment was conducted to verify the accuracy of the simulation results. A series of orthogonal experiments were conducted on the initial preheating temperature of various components to identify the optimal parameters in order to achieve better porosity and stress concentration values. According to the results and analyses, the preheating temperature of the mold was the most important determining factor. Under a pouring temperature of 700 °C, mold preheating temperature of 200 °C, and SiC skeleton preheating temperature of 600 °C, the maximum principal stress at the bottom of the products was decreased by about 41.9%, and the shrinkage volume inside the composite was decreased about by about 61.6%. Thus, by adjusting the initial preheating temperature of various components, the squeeze-casting SiC3D/Al composites could achieve better performance and fewer internal defects.
Roles of Myokines and Muscle-Derived Extracellular Vesicles in Musculoskeletal Deterioration under Disuse Conditions
Authors: Zhang Jie , Gao Yunfang , Yan Jiangwei
Published: January 2024

Prolonged inactivity and disuse conditions, such as those experienced during spaceflight and prolonged bedrest, are frequently accompanied by detrimental effects on the motor system, including skeletal muscle atrophy and bone loss, which greatly increase the risk of osteoporosis and fractures. Moreover, the decrease in glucose and lipid utilization in skeletal muscles, a consequence of muscle atrophy, also contributes to the development of metabolic syndrome. Clarifying the mechanisms involved in disuse-induced musculoskeletal deterioration is important, providing therapeutic targets and a scientific foundation for the treatment of musculoskeletal disorders under disuse conditions. Skeletal muscle, as a powerful endocrine organ, participates in the regulation of physiological and biochemical functions of local or distal tissues and organs, including itself, in endocrine, autocrine, or paracrine manners. As a motor organ adjacent to muscle, bone tissue exhibits a relative lag in degenerative changes compared to skeletal muscle under disuse conditions. Based on this phenomenon, roles and mechanisms involved in the communication between skeletal muscle and bone, especially from muscle to bone, under disuse conditions have attracted widespread attention. In this review, we summarize the roles and regulatory mechanisms of muscle-derived myokines and extracellular vesicles (EVs) in the occurrence of muscle atrophy and bone loss under disuse conditions, as well as discuss future perspectives based on existing research.
Temperature Dependence of Platelet Metabolism
Authors: Jóhannsson Freyr , Yurkovich James T. , Guðmundsson Steinn , Sigurjónsson Ólafur E. , Rolfsson Óttar
Published: January 2024

Temperature plays a fundamental role in biology, influencing cellular function, chemical reaction rates, molecular structures, and interactions. While the temperature dependence of many biochemical reactions is well defined in vitro, the effect of temperature on metabolic function at the network level is poorly understood, and it remains an important challenge in optimizing the storage of cells and tissues at lower temperatures. Here, we used time-course metabolomic data and systems biology approaches to characterize the effects of storage temperature on human platelets (PLTs) in a platelet additive solution. We observed that changes to the metabolome with storage time do not simply scale with temperature but instead display complex temperature dependence, with only a small subset of metabolites following an Arrhenius-type relationship. Investigation of PLT energy metabolism through integration with computational modeling revealed that oxidative metabolism is more sensitive to temperature changes than glycolysis. The increased contribution of glycolysis to ATP turnover at lower temperatures indicates a stronger glycolytic phenotype with decreasing storage temperature. More broadly, these results demonstrate that the temperature dependence of the PLT metabolic network is not uniform, suggesting that efforts to improve the health of stored PLTs could be targeted at specific pathways.
A New Model for Predicting Drag Coefficient and Settling Velocity of Coarse Mineral Particles in Newtonian Fluid
Authors: Xu Zhenqiang , Shen Kaixiang , Zhang Kewei , Guo Nana , Li Zijian
Published: January 2024

Efficient transport in vertical pipeline hydraulic lifting systems is vital for coarse-grained ore, necessitating a deep comprehension of the settling traits of coarse mineral particles. In this study, we conducted a series of settling experiments on individual coarse particles in Newtonian fluids with varying viscosities, employing a self-designed and manufactured settling apparatus. A total of 133 sets of experimental data on the free settling of coarse particles in Newtonian fluids were obtained by recording the particle settling process with a high-speed camera and applying image processing techniques. A mechanical model was employed to perform statistical analysis on the experimental data and establish a predictive model for the drag coefficient and an explicit predictive model for the settling terminal velocity of coarse-grained ore in Newtonian fluids. The average relative errors between the predicted values and experimental values of the drag coefficient and settling terminal velocity models are 4.26% and 7.34%, respectively. This confirms the reliability of the provided predicted model, providing a theoretical foundation for determining the hydraulic lifting speed of coarse mineral particles in vertical pipelines for deep mining.
Natural Deep Eutectic Solvents for the Extraction of Spilanthol from Acmella oleracea (L.) R.K.Jansen
Authors: Alperth Fabian , Feistritzer Theresa , Huber Melanie , Kunert Olaf , Bucar Franz
Published: January 2024

With a growing focus on green chemistry, the extraction of natural products with natural deep eutectic solvents (NADES), which are eutectic mixtures of hydrogen bond donors and acceptors, has become an ever-expanding field of research. However, the use of NADES for the extraction of spilanthol from Acmella oleracea (L.) R.K.Jansen has not yet been investigated. Therefore, in this study, 20 choline chloride-based NADES, and for comparison, ethanol, were used as green extraction agents for spilanthol from Acmella oleracea flower heads. The effects of time, water addition, and temperature on NADES extractions were investigated and analysed by HPLC-DAD quantification. Additionally, UHPLC-DAD-ESI-MSn results for dichloromethane extracts, as well as the isolation of spilanthol and other main constituents as reference compounds, are reported. The best green extraction results were achieved by choline chloride (ChCl) with 1,2-propanediol (P, 1:2 molar ratio, +20% water) at 244.58 µg/mL, comparable to yields with ethanol (245.93 µg/mL). Methylurea (MeU, 1:2, +20% water) also showed promising results as a hydrogen bond donor in combination with choline chloride (208.12 µg/mL). In further experiments with NADES ChCl/P (1:2) and ChCl/MeU (1:2), extraction time had the least effect on spilanthol extraction with NADES, while yield decreased with water addition over 20% and increased with extraction temperature up to 80 °C. NADES are promising extraction agents for the extraction of spilanthol, and these findings could lead to applicable extracts for medicinal purposes, due to their non-toxic constituents.
Study on the Catalytic Oxidation of Toluene Using CeO2@S-AZMB Prepared from Spent Zn-Mn Batteries
Authors: Zou Yu , Du Huan , Zhao Zhong , Wang Zhuozhi
Published: January 2024

The recycling and utilization of waste alkaline zinc manganese batteries (S-AZMB) has always been a focus of attention in the fields of environment and energy. However, current research mostly focuses on the recycling of purified materials, while neglecting the direct reuse of waste batteries. Here, we propose a new concept of preparing thermal catalysts by combining unpurified S-AZMB with CeO2 by means of ball milling. A series of characterizations and experiments have confirmed that the combination with S-AZMB not only enhances the thermal catalytic activity of CeO2 but also significantly enhances the concentration of surface oxygen vacancies. In the toluene removal experiment, the temperature (T90) at 90% toluene conversions of CeO2@S-AZMB was 180 °C, lower than the 220 °C for CeO2. More noteworthy is that this S-AZMB-based thermal catalyst can maintain a good structure and thermal catalytic stability in cyclic catalysis.
Preparation, Characterization, and Antioxidant Activities of Extracts from Amygdalus persica L. Flowers
Authors: Yu Qingtao , Li Wenzhi , Liang Ming , Li Guohu , Wu Zhuoyan , Long Jieyi , Yuan Chanling , Mei Wenjie , Xia Xiaole
Published: January 2024

A novel water-soluble Amygdalus persica L. flowers polysaccharide (APL) was successfully isolated and purified from Amygdalus persica L. flowers by hot water extraction. Its chemical components and structure were analyzed by IR, GC-MS, and HPLC. APL consisted of rhamnose, arabinose, mannose and glucose in a molar ratio of 0.17:0.034:1.0:0.17 with an average molecular weight of approximately 208.53 kDa and 15.19 kDa. The antioxidant activity of APL was evaluated through radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 3-ethylbenzthiazoline-6-sulfonic acid (ABTS), Hydroxyl radical scavenging, Superoxide radical scavenging, and the reducing power activity was also determined in vitro. Besides, in vivo antioxidant experiment, zebrafish (Danio rerio) embryos were treated with different concentrations of APL and then exposed to LPS to induce oxidative stress. Treatment with APL at 50 or 100 µg/mL significantly reduced LPS-induced oxidative stress in the zebrafish, demonstrating the strong antioxidant activity of APL. Moreover, the effect of APL on zebrafish depigmentation was tested by analyzing the tyrosinase activity and melanin content of zebrafish embryos. APL showed a potential reduction in the total melanin content and tyrosinase activity after treatment. This work provided important information for developing a potential natural antioxidant in the field of cosmetics and food.
Biochemical Assessments of Six Species of Edible Coastal Algae Collected from Tabuk Region in Saudi Arabia
Authors: Bayomy Hala M. , Alamri Eman S.
Published: January 2024

In the first study focusing on the Red Sea’s Tabuk coast, six edible species of the most common algae were collected to evaluate their approximate composition using AOAC methods, amino acids using ion-exchange chromatography, minerals using atomic absorption spectroscopy, phenolic compounds using the Folin–Ciocalteu method, and ferric-reducing antioxidant power. All the data were significantly (p < 0.05) different among all the studied species. The data indicated that the protein content ranged from 9.25% for A. nodosum to 20.06% for H. musciformis. C. racemosa had the highest lipid content of 7.57%. Phosphors varied from 68.2 mg/100 g for A. nodosum to 406 mg/100 g for D. simplex. The largest amounts of calcium (2458 mg/100 g) and iron (29.79 mg/100 g) were found in C. racemosa. The total essential amino acids ranged between 38.16 and 46.82% for A. nodosum and D. simplex, respectively. F. vesiculosus had the maximum content of phenolic compounds (11.06 mg GAE/g). A. nodosum had the highest antioxidant capacity (1.78 mg TE/g). The research concluded that algae are the main effort toward sustainable agriculture to meet the world’s food needs. that algae may be used to improve food naturally. To satisfy the criteria for sustainable food, which is one of the pillars of NEOM, numerous studies are required to investigate the natural products available in the Red Sea.