Silicon最新文献

The LIGBT is a type of Insulated Gate Bipolar Transistor (IGBT) featuring a lateral structure, which enables easy integration. A reverse conducting LIGBT device with an integrated self-biased punch-through NPN transistor is proposed(NPN-LIGBT). The proposed LIGBT integrates a punch-through NPN transistor in the N-buffer region of the anode on the basis of a conventional LIGBT device. The key point is that the width of the P-Base of the NPN transistor is narrower and the doping concentration is lower, so when a positive voltage is applied to the anode, the depletion region will be extended to the P-Base and penetration occurs, and at this time, the NPN transistor provides a carrier channel to extract electrons from the drift region, which reduces the forward saturation current of the device and can function in both reverse conduction and turn-off states as well as enable the device to operate in forward conduction without the snapback effect. At the same on-state voltage drop of V_on = 1.7 V, compared with traditional LIGBTs and SSA LIGBTs, the turn-off loss E_off of the NPN-LIGBT is reduced by 37% and 8%, respectively.

This study aims to comparatively investigate the structural, mechanical and drilling performances of as-cast AlSi10Mg and AlSi10MgCu alloys manufactured by gravity casting method. The alloys were subjected to microstructure, hardness, tensile and drilling. Microstructural analyses showed that Cu addition caused spheroidization of eutectic Si particles, formation of precipitate phases such as θ-Al₂Cu and Al₅Mg₈Cu₂Si₆ and increased heterogeneity in the matrix structure. According to the mechanical test results, the addition of Cu increased hardness by 6.67%, yield strength by 6.25%, and tensile strength by 20%, while elongation to fracture decreased by 14.28%. Drilling tests revealed that the lowest thrust force (Fz = 72.13 N) and torque (Mz = 32.70 Ncm) were obtained at cutting speed (V) = 155 m/min and feed (f) = 0.04 mm/rev. Furthermore, chip morphology and tool-tip observations indicated that Cu addition reduced built-up edge (BUE) formation and enhanced chip breakability, improving machinability. The Response Surface Methodology (RSM) models exhibited high reliability with R² values above 97%, and Analysis of Variance (ANOVA) confirmed the significant influence of feed rate on both responses. The obtained data provide important insights for optimizing machining parameters and understanding the positive influence of Cu addition on machinability.

This study investigated the potential of Cocoa Pod Ash (CPA) and Rice Husk Ash (RHA), respectively, as sustainable sources of potassium and amorphous silica, in the preparation of activating solutions for geopolymerization. CPA was successfully used to extract K-salt that was found to be a carbonate salt using FTIR analysis. The K-salt was used as a substitute of NaOH, together with RHA as silica source to prepare activating solutions via hydrothermal dissolution. The obtained activating solutions were successfully used in the geopolymerization of both calcined kaolinitic and lateritic clays. The synthesized geopolymers were characterized using X-ray Diffraction (XRD), Fourier transformed infrared (FTIR) and the measurement of some physico-mechanical parameters. Including setting time, compressive strength, density, porosity and water absorption. The results indicate an improved response of the geopolymer products with K-salt addition of 15-20% (w/w), with respect to total alkali. Beyond 20%, there was a lowering of the various responds that were associated with matrix weakening brought by carbonatation. The alkalinity of all the activating solutions was sufficient for geopolymerization without retention of excess alkali ions in the binder system, as indicated by the absence of efflorescence on the geopolymer surfaces. This study demonstrates the potential of using locally sourced agro-wastes materials to produce sustainable activating solutions.

This research investigates the wear and friction behavior, alongside mechanical properties, of Al7475 composites reinforced with SiO₂ derived from palm oil ash and TiO₂ from mining tailings, under both dry and SAE 20 lubricated conditions. Mechanical properties including tensile strength, flexural strength, Charpy impact energy, and hardness were evaluated, complemented by microstructural analysis via SEM. Wear and friction characteristics were assessed by measuring the coefficient of friction (COF) and specific wear rate. The findings reveal that the 3 vol.% TiO₂ reinforced composite (M4) exhibited superior overall mechanical performance, achieving a tensile strength of 550.3 MPa, a flexural strength of 578 MPa, and a Charpy impact energy of 32 J, attributed to optimal particle dispersion and efficient load transfer. Conversely, the 5 vol. % SiO₂ reinforced composite (M2) demonstrated exceptional tribological properties and hardness, reaching a hardness of 202 BHN. Under dry sliding, M2 showed the lowest specific wear rate of 0.0048 mm³/Nm and a COF of 0.45. This excellent wear resistance persisted under wet conditions with SAE 20 lubricant, where M2 recorded an even lower specific wear rate of 0.0042 mm³/Nm and a COF of 0.43, primarily due to the higher volume fraction of hard SiO₂ particles forming a stable tribolayer that synergizes with the lubricant. The results underscore the potential of these sustainable reinforcements for developing high-performance Al7475 composites for tribological applications.

This paper presents a graphene and vanadium dioxide-based planar antenna optimized for THz Defence surveillance and secure communication applications. It is made up of silicon di oxide, graphene, vanadium di oxide, silver feedline, PEC etc. The integration of these materials enhances conductivity, tunability, and efficiency, making the design well-suited for high-frequency operations. The antenna is excited using proximity coupling with a Y-shaped structure, ensures optimized impedance matching and stable radiation characteristics. The proposed antenna resonating at 1.1 THz, 1.9 THz, 2.5 THz, 3.03 THz, 3.1 THz, 3.21 THz respectivelly, it achieves an excellent return loss of -20.1 dB, -12.3 dB, -14.15 dB, -29.90 dB, -18.1 dB, 16.4 dB respectivelly, ensuring minimal reflection and efficient power transfer. The antenna maintains circular polarization, confirmed by an axial ratio below 3 dB, which is further validated through electric and magnetic field distributions, demonstrating polarization stability. It also exhibits a high radiation efficiency of 94.86%, making it a strong candidate for defense and surveillance systems. With a maximum directivity of 11.1 dBi, the antenna ensures robust radiation performance with well-defined circular polarization characteristics. Additionally, 2D and 3D radiation patterns provide a detailed analysis of its radiation behavior, while the nomenclature of field distribution offers insights into near-field characteristics crucial for polarization stability. The findings contribute to next-generation THz communication and surveillance technologies, paving the way for high-performance electronic systems in strategic and military applications.

This study investigates the effect of fine-to-coarse aggregate ratios on the permeability and freeze–thaw behavior of concrete incorporating magnetized water. As a widely used composite material, concrete’s durability against water penetration and freeze–thaw cycles is critical, particularly in harsh environmental conditions. Magnetized water, produced by passing water through a magnetic field to alter its physical properties, represents an innovative approach to enhancing concrete’s mechanical properties and durability. The research evaluated 15 mix designs with fine-to-coarse aggregate ratios (0.5 to 1.5) and cement contents (350, 400 and 450 kg/m³). Results demonstrated that concrete with magnetized water significantly improved compressive strength by up to 38.1% and freeze–thaw resistance, while reducing water permeability by up to 68.8% compared to concrete with ordinary water. An optimal aggregate ratio (0.75 to 1.0) and higher cement content (450 kg/m³) yielded the best performance in minimizing permeability and maximizing compressive strength. Life Cycle Assessment (LCA) revealed that magnetized water concrete reduces environmental impact and production costs by eliminating the need for chemical admixtures. The novelty of this research lies in leveraging magnetized water as a cost-effective and sustainable method to enhance concrete durability, particularly in cold climates. This approach not only complies with international standards (ACI 318 and Eurocode 2) but also offers comparable performance to costly additives like silica fume at a lower cost. By providing a practical and economical solution for producing durable concrete, this study has significant implications for civil engineering projects in challenging environmental conditions, promoting sustainability and cost-efficiency in construction practices.

This study explores the adsorption of Malachite Green (MG) dye from aqueous solution using an Ag@g-C₃N₄-SiO₂ nanocomposite. The g-C₃N₄-SiO₂ composite was first synthesized by the sol–gel method and subsequently modified with silver nanoparticles. The prepared material was characterized using FTIR, XRD, FE-SEM, EDX, and EDS analyses. The formation of layered g-C₃N₄ nanosheets grew uniformly on the surface, cubic Ag and the amorphous nature of the SiO₂ was confirmed by XRD. Different adsorption parameters such as contact time, initial MG dye concentration, adsorbent dosage, and stirring speed were optimized. The adsorption process followed the pseudo-second-order kinetic model. Batch adsorption studies revealed that the optimal conditions were an initial MG dye concentration of 30 mg/L, an adsorbent dosage of 100 mg, a contact time of 30 min, and a stirring speed of 250 rpm. The Langmuir isotherm model best described the adsorption behaviour with a high correlation coefficient (R² = 0.99), and the maximum adsorption capacity was 102.35 mg/g. The initial MG dye concentration ranged from 10 mg/L to 80 mg/L. Furthermore, the nanocomposite showed good reusability, maintaining 62% dye removal efficiency after four cycles. The adsorption mechanism involved hydrogen bonding, electrostatic, and π–π interactions.

This work presents a comprehensive investigation of GaN-based Junctionless Drain Extended Longitudinal FinFET (DELFinFET) using Sentaurus TCAD simulations, targeting thermally robust and energy efficient semiconductor devices as a means to reduce the environmental footprint of electronic devices. Introducing a longitudinal fin achieves superior lateral electric field modulation, improved carrier transport, and enhanced electric control. This helps in improving the key analog performance metrics such as sub-threshold slope, leakage current ((I_{off})), transconductance ((g_m)), and the switching ratio ((I_{on})/(I_{off})). The results obtained highlight the potential of DELFinFET for low-power applications. A comparative evaluation is performed between the designed device and other device configurations to verify the effectiveness of the design.

The mechanical, thermal, and water-absorption characteristics of epoxy composites reinforced with maguey fiber and cellulose treated with silane are examined in this work. The addition of silane-treated cellulose greatly increased the composites’ tensile strength; specimen EMC1, which contained 1 vol.% cellulose, had the maximum tensile strength of 139 MPa and the highest flexural strength of 160 MPa. Because of the silane-treated cellulose’s ideal dispersion, which improved interfacial bonding and stress transfer, EMC1 also showed the maximum impact strength, measuring 6.5 J. On the other hand, specimen EMC2, which included 2 vol.% cellulose, had exceptional water and heat resistance, with the lowest water absorption value of 0.042% and the lowest thermal conductivity of 0.23 W/mK. These characteristics come from EMC2’s greater filler content, which maintains strong mechanical performance while obstructing heat conduction channels and forming hydrophilic spots. With specimen EMC1 exhibiting better filler-matrix bonding and EMC2 exhibiting filler agglomeration at higher concentrations, SEM analysis further validated the function of silane-treated cellulose in improving interfacial adhesion and stress transfer. The study’s overall findings demonstrate the possibility of silane-treated cellulose and maguey fiber as efficient reinforcements for epoxy composites in applications needing improved moisture, heat, and mechanical resistance.

Drought stress, which occurs unpredictably and repeatedly, negatively affects the success of afforestation. This study aimed to investigate the morpho-physiological responses of stone pine (Pinus pinea L.) seedlings treated with silicon-based fertilizer under the impact of drought stress. The main research question was whether silicon-based fertilizers could enhance the drought resistance of seedlings by improving their water content, photosynthetic activity, and growth parameters. A four-week pot experiment was conducted with two main treatment groups: well-watered and drought-stressed. Three different silicon-based fertilizer doses (0 g, 15 g, and 30 g per seedling/pot) were applied to each group. Morphological (height and diameter increment, biomass) and physiological (water potential, relative water content, and chlorophyll fluorescence) parameters of the seedlings were measured. To assess the visual symptoms of tissue damage at the end of the drought experiment, the visual severity of all treated seedlings was also evaluated. The results showed a significant interaction between doses and treatments for height increment (P < 0.05) while no significant effects were observed for diameter increment. Silicon-based fertilization improved drought tolerance in stressed seedlings by enhancing their midday relative water content and photosynthetic activity. Notably, moderate doses (15 g per seedling/pot) was found to be effective in mitigating drought-induced stress and promoting faster recovery after the stress period. The findings demonstrate that silicon-based fertilizers have the potential to enhance the drought resistance of stone pine seedlings, offering a promising strategy for afforestation efforts in drought-prone regions.