română FANG HUO
Abstract
Ankle injuries in martial arts arise from high-intensity impacts and complex torsional loads. To overcome the trade-off between biocompatibility and mechanical strength in conventional repair materials, we designed a nanostructured hydroxyapatite (HA)/polylactic acid (PLA) composite scaffold. Nano-HA particles were synthesized via controlled solid-state milling (average diameter ~80 nm) and uniformly dispersed in a PLA matrix, then fabricated by 3D printing. We employed BET surface area analysis, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) to characterize pore size distribution and HA–PLA interfacial structure. In vitro tests showed that at 15 wt% HA loading, mesenchymal stem cell proliferation increased by 25% at 42 h, Runx2 expression was upregulated by 30% at day 15, and compressive strength reached 6.0 MPa—significantly higher than controls. Finite element modeling revealed that the nanoscale porous architecture effectively redistributes stress and mitigates concentration. These results demonstrate a clear design–microstructure–performance relationship for nanostructured bone repair scaffolds, offering new insights for high-performance materials in sports injury treatment.
Keywords
Ankle Injury, Biomechanical Mechanism, Tissue Engineering, Bone Repair Materials, Sports Injury Repair, Biocompatibility, Mechanical Properties
WEI ZHENG
Abstract
This work presents an optoelectronic study of cobalt-doped nano-TiO2 camouflage films prepared via a non-hydrolytic sol–gel route and examines their suitability for device integration. Photoluminescence (PL) and UV–Vis absorption measurements show that the films possess a tunable bandgap (3.12–3.24 eV) and exhibit a rapid photoconductive response under visible illumination, with a rise time of about 15 ms and a decay time of roughly 25 ms. SEM observations indicate a highly uniform film morphology, and UV aging tests verify that the coatings retain their structural and optical stability in ambient conditions. When these materials are incorporated into prototype thin-film photodetectors, the devices achieve an on/off photocurrent ratio exceeding 10³ and a responsivity of 0.15 A/W at 450 nm, pointing to their practical promise for adaptive optical filters and smart window coatings. In addition, assessment of visual performance shows that nanoscale optical camouflage layers deliver an average increase of 0.91 points in visual impact over conventional materials, underscoring the capacity of nanoscale optical and electronic architectures to reshape graphic design by enabling more dynamic and aesthetically compelling visual experiences.
Keywords
Nanoscale Optical Camouflage Materials, Electronic and Optoelectronic Properties, Nano Titanium Dioxide, Graphic Design Enhancement, Sol-Gel Process
CHUFENG TAO
Abstract
A novel nanoscale optoelectronic imaging platform is presented that leverages quantum-dot–sensitized sensors together with a hybrid clustering strategy to realize ultra-high-speed acquisition and analysis of rapid nanoscale phenomena. By embedding CdSe/ZnS quantum dots into a plasmonic imaging circuit and feeding the sensor output into a modified k-means routine steered by an artificial fish swarm algorithm (AFSA), data redundancy is suppressed and representative keyframes are extracted in real time. Experiments tracking plasmonic nanoparticle motion under pulsed excitation show a 9.96 % rise in clustering accuracy and a 7.44 % increase in recall relative to standard k-means, accompanied by a 0.086 improvement in the silhouette coefficient. Collectively, these results demonstrate concurrent gains in spatial resolution (down to 50 nm) and temporal resolution (sub-microsecond). Demonstrations in in-situ nanomanufacturing quality monitoring and single-molecule bioimaging further illustrate the platform’s applicability across nanoelectronics and optoelectronic systems.
Keywords
Nanoscale Optoelectronics, Ultra-High-Speed Optical Imaging, Nanomaterials in Imaging Technology, Image Processing Algorithms, High-Speed Phenomena Analysis
MARIA ELIZA PUSCASU, CRISTINA BUSUIOC
Abstract
In the recent years, bone has become the second most transplanted tissue at the global level as a result of increased number of accidents, pathologies and prolonged lifetime span. Currently, there are significant limitations in the available materials for the bone tissue transplantation and there is a high demand for the research of suitable substituents. Following the bone composition and intricate architecture, a grafting material with high potential in bone tissue engineering may be obtained. Bioceramics from the system CaO‒MgO‒SiO2 (ex. diopside, akermanite and merwinite) have excellent bioactivity and are similar with hydroxyapatite from biological point of view, having improved mechanical resistance. Considering the complex inner architecture of the bone, one of the most suitable fabrication methods in the bone tissue engineering is 3D printing as this technique facilitates manufacturing of intricate inner structures with a high control on the infill parameters. In this work diopside, akermanite and merwinite based powders were obtained using both sol-gel and combustion methods. All obtain powders were characterized using X-ray diffraction, while diopside and merwinite powders were characterized from morphological point of view by scanning electron microscopy. Further on, the obtained powders were mixed with an organic additive in order to obtain a printable paste with characteristic adequate for robocasting process. A comparison between the impact of the synthesis method in the paste formulation was further assessed. The obtained 3D scaffolds were evaluated from morphological point of view using Scanning Electron Microscopy. The results suggested that the synthesis method plays an important role in the paste formulation for the 3D printing process and that diopside, akermanite and merwinite based scaffold can be successfully obtained by robocasting method.
Keywords
Calcium Magnesium Silicates; Sol-Gel; Combustion; Robocasting, Bone Tissue Engineering
ELENA CHIȚANU, MIRELA MARIA CODESCU, VIRGIL MARINESCU, ISTVAN BORBÁTH
Abstract
Nanomaterials have attracted considerable attention due to their flexible synthesis methods and wide-ranging functional applications. Among these, SiO2 nanoparticles have attracted significant attention owing to their controllable physicochemical properties, which can be precisely engineered for specific biomedical applications. Since its introduction in 1968, the Stöber method—despite undergoing only minor refinements—has remained the most widely adopted approach for the synthesis of nanoscale SiO2. Due to their morphology and particle size, SiO2 nanoparticles are particularly suitable for use in advanced manufacturing techniques such as three-dimensional (3D) printing, especially within biomedical engineering applications, including bone tissue regeneration. In such contexts, SiO2 nanoparticles are typically dispersed in suspensions, where knowledge of their surface charge is essential, as it plays a critical role in governing their aggregation and colloidal stability. However, existing measurement techniques do not permit direct and accurate quantification of surface charge; consequently, this parameter is often indirectly estimated through the determination of zeta potential. This study presents the tetraethyl orthosilicate (TEOS) concentrations influence on the stability of the SiO2 suspensions. The SiO2 nanoparticles were prepared by classic Stöber technique, with spherical uniform geometry and average sizes starting from 152 nm up to 681 nm due to increasing concentration of TEOS. To determine the zeta potential, suspensions containing 0.05 wt.% SiO2 were prepared in solutions with pH values ranging from 1 to 12. Under alkaline conditions (pH 12), the smallest SiO2 nanoparticles exhibited zeta potential values of up to −58.4 mV, indicating that the analysed suspensions were stable in this medium.
Keywords
silica 3D printing, Stöber method, suspensions stability, zeta potential
STARLIN DEVA PRINCE JOHN SAHAYAM, ARUL FRANCO PANIMAYAM, NAVANEETHA KRISHNAN MUTHU NADAR, MICHAEL RAJ FRANCIS
Abstract
Making high-performance hybrid composites from discarded fishnets may improve sustainability. Hand-lay-up is used to blend glass fibre and epoxy resin in the study. ASTM standards were followed to quantify tensile, flexural, and impact force. Multiple acid solutions Hydrochloric Acid (HCL), Sulphuric Acid (H2SO4), Acetic Acid (CH3COOH) applied to nylon fishnets destroyed pollutants and strengthened composite assemblies based on Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) analysis results. Treated consequences demonstrated superior material properties because tensile strengths achieved 50.71 MPa and flexural strengths measured 40.5 MPa while possessing strong impact resistance. A distribution of materials across the hybrid composites along with minimal voids and improved durability made these composites suitable for marine applications which include boat hulls and structural components. Water absorption tests proved excellent resistance capabilities because the composites exhibited low levels of moisture absorption thus maintaining stability when immersed in water. This research dual-purpose project tackles marine pollution and promotes a circular economy via sustainable development by integrating recycled materials into sophisticated composite systems. Chemically modified waste polymers in ecologically friendly engineering applications may improve engineering materials and performance.
Keywords
Sustainable composites, Recycled nylon fishnets, Glass fiber reinforcement, Epoxy resin matrix, Marine pollution mitigation, Mechanical property enhancement
SAID MOHAMED ELAMIN, BENOUMANE SALLAI, YASSINE KHALFI, ALAMI AHMED, BACHIR BOUIADJRA BACHIR, BENOUIS KHEDIDJA, GUELLA SOUFIANE, BELHIA SOUAD
Abstract
Utilization of agricultural waste for construction materials is an emerging pathway for sustainable development. This study examines the valorization of the Washingtonia filifera palm fibers, one of the main agricultural by-products in Algeria, as a reinforcing material for concrete. Various concentrations and optimum conditions of sodium hydroxide (NaOH) solutions were used to extract the fibers, and subsequently tensile characterization was carried out. The fiber undergone at 2% NaOH for 96 hours has been found to have a 225.95 MPa tensile strength and a 7.85 GPa Young’s modulus. Concrete mixtures were made with 0.5%, 1%, and 1.75% palm fibers by weight of cement. According to mechanical testing, the incorporation of fibers resulted in a slight loss of early age compressive strength, mainly due to porosity. However, as the curing age progressed, the strength performance gradually recovered. The compressive strength of 1.75% fiber blend at 28 days was a maximum of 26.79 MPa. Similarly, flexural tensile strength was notably increased as it achieved a value of 5.96 MPa which was nearly 22% higher than the control. The results show that palm fibers can be converted to effective and green reinforcements when treated appropriately, offering benefits to both engineering applications and the environment.
Keywords
Natural fibers, Fiber-reinforced concrete, Alkali treatment, Cement hydration chemistry, Sustainable construction
MOHAMED CHAKIB KHERRABI, MOHAMMED SI-AHMED, AMAR BENYAHIA, MESSAOUD SAIDANI, SAID KENAI
Abstract
Carbon dioxide emissions, natural resources consumption, and inert waste production represent significant challenges in the construction industry. The use of recycled aggregates and supplementary cementitious materials in mortar and concrete offer promising solutions to these issues. This study investigates the combined effect of recycled sand from brick waste and calcined clay-based cement on the behavior of self-compacting mortar (SCM). The novelty of this work lies in assessing both the mechanical performance and the carbon footprint of these alternative materials. Natural sand (NS) was substituted with recycled brick sand (BS) at proportions 10, 20, 30, and 40% by volume, while cement was partially replaced with 10 and 15% by mass of calcined clay (CC). A series of laboratory tests were carried out to evaluate workability, compressive strength, shrinkage, and microstructural properties. The results indicate that the combination of CC and BS decreases workability and shrinkage, increases compressive strength by up to 23%, and improves the microstructure of the mixtures. The mixtures based on BS and CC are the most ecological with a reduction in the carbon footprint and with the eco-mechanical index (EMI) reaching 28% compared to the control mortar.
Keywords
Recycled brick sand, calcined clay, Self-compacting mortar, Compressive strength, shrinkage, Carbon footprint
CICI JENNIFER RAJ J, KUMAR G, BASKAR S
Abstract
This experimental study investigates the feasibility and performance characteristics of incorporating treated rubber industrial wastewater as a sustainable alternative to potable water in concrete production. The research systematically evaluates the mechanical properties and microstructural characteristics of M25 grade concrete with and without rubber industrial waste water (RIWW) using Scanning Electron Microscopy. The study is exclusively dealt with the behaviour of RIWW, with and without admixtures. From the study, it is observed that compressive strength of the concrete using RIWW and admixtures is 25% to 30% greater compared to other concrete only with RIWW. Furthermore, higher replacement levels displayed tiny voids and microcracks, suggesting a small slowdown in hydration, while concretewith potable water had a dense and well-hydrated microstructure with consistent C-S-H gel formation, according to SEM images.
Keywords
Rubber Industrial Water, Compressive Strength, SEM Analysis, CSH gel
KARTHIKEYAN SAMBANDHAM, BASKAR NEELAKANDAN, GANESAN MANICKAM, RAMKUMAR KATHALINGAM
Abstract
Friction welding is an efficient and economical process of joining two similar or dissimilar metals among various welding processes. Now-a-days, the automobile and other industries are using dissimilar metals in a same working area to compensate the problems faced due to temperature and working atmosphere to enhance company’s economy. The material AA6351 and EN353 alloy steel have wide applications in aerospace & automobile industries, are joined with different input parameters like Heating Time (HT), Heating Pressure (HP), Upset Time (UT), Upset Pressure (UP) with constant rotation. These input parameters are ordered using L27 Taguchi Orthogonal Array (OA) to experiment the process. Friction welding is done in KUKA friction welding machine. After experimentation, the responses like temperature, hardness and axial shortening are measured. Using these responses, the optimization is carried out through Grey Relational Analysis (GRA) and the rankings are identified and tabulated to obtain the optimal solutions. Based on rankings, the optimal input parameters are concluded as 18 bar of Heating Pressure (HP), 7 sec of Heating Time (HT), 22 bar of Upset Pressure (UP) and 3 sec of Upset Time (UT). The Field Emission Scanning Electron Microscope (FESEM) analysis is also used to study the Inter-metallic compounds (IMCs).
Keywords
Friction Welding, AA6351, EN353, Grey Relational Analysis, FESEM analysis
GUIZHEN WANG, LINGLONG ZHOU
Abstract
This study explores the seismic reinforcement of coastal buildings through the innovative application of Shape Memory Alloys (SMAs). SMAs, a novel class of functional materials, exhibit unique properties like shape memory effect, superelasticity, and high damping performance, making them ideal for seismic applications. Recognizing the critical role of structural design in a buildings earthquake resistance, this research introduces an SMA-based damper specifically tailored for coastal structures, considering their unique stress profiles and disaster vulnerability. Through experimental and simulation methods, including MATLABs Simulink module, the study compares the seismic responses of conventional coastal building designs with those incorporating the SMA damper. The results reveal that the SMA dampers bilinear restoring force mechanism significantly enhances vibration suppression, offering a promising solution for seismic reinforcement in building construction. This investigation not only contributes to the understanding of SMA materials but also underscores their potential in structural earthquake resilience, marking a significant intersection of material science, engineering, and seismic technology.
Keywords
Shape Memory Alloys (SMAs); Seismic Dampers; Coastal Building Reinforcement; Earthquake Resistant Structures; Superelastic Materials
ANCA MIHAELA MOCANU, ANDREEA IOANA SUSANU
Abstract
The paper explores the domain of digitally fabricated dental prostheses, specifically detailing the application of CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) methodologies within the field of restorative dentistry. The research undertakes a thorough examination of the digital fabrication sequence in prosthodontics, which encompasses critical phases such as intraoral/laboratory scanning, CAD modeling, automated milling, and final surface treatment. A significant portion of the work is dedicated to the CEREC system implementation in the chairside clinical environment (i.e., procedures completed within the dental practice). Furthermore, the study includes an assessment of the specialized equipment and the mechanical behavior of three notable restorative biomaterials: Zirconium Dioxide, IPS e.max Ceram Dentin, and Cerasmart. The CEREC system is a computerized system that can be used to design and produce, in a single session, highly accurate, aesthetic, and durable ceramic restorations for small cavities. The dental materials were analyzed both before and after the firing process using infrared absorption spectroscopy (FITR), and the morphology of the samples was highlighted using a high-resolution scanning electron microscope equipped with an EDX detector and thermal analysis (TG-DTG-DTA). The characterization methods were applied to compare the performance of the three materials, with a focus on marginal adaptation, aesthetics, strength, and ease of processing, and to highlight the essential differences between the materials in the context of their use in dental restorations. The results of this study, together with data from the literature, help to understand the interaction of these materials with tissues and also to modify the properties of these materials.
Keywords
ceramic kits, CAD/CAM technique, absorption spectroscopy, scanning electron microscopy, thermal analysis
ANDREI GÎRBOVEANU, ANDREI ZYBACZYNSKI, MUHEEB ALTALEB, DAN PAUL GEORGESCU
Abstract
This article presents arguments that result both from the specialized technical literature but also demonstrated theoretically and through experimental tests by the authors related to the fact that fiber reinforcement also represents a solution to improve the durability of reinforced concrete. Fiber reinforced concrete has particularities that lead to the improvement of transport mechanisms such as permeability or diffusion but also in terms of reducing the level of specific strains as well as the opening of cracks, which influence these transport mechanisms, at the same levels of stress compared to ordinary reinforced concrete. In accordance with research carried out internationally [1] In the case of steel fiber reinforced concrete, corrosion is much less severe compared to continuous steel reinforcement of concrete structures and the degradation of cracked steel fiber reinforced concrete due to fiber corrosion depends on several parameters, such as: crack opening, aggressiveness of environmental conditions and fiber type. The calculations presented in the article indicated that fiber reinforced concrete exhibits a smaller crack opening for the same conditions related to concrete composition or stress level compared to ordinary reinforced concrete. The results of experimental research carried out on prestressed concrete elements in which the transverse reinforcement with stirrups was replaced with fiber reinforcement in the central area of the opening have highlighted a decrease in specific strains for the same stress levels when using fiber reinforcement, which indicates a reduction in microcracking, lower permeability and, implicitly, increased resistance to the penetration of external agents, thus contributing to improved durability.
Keywords
Concrete, fiber reinforcement, environmental conditions, durability, prestressed concrete, stirrups, deformations