Papers by Keyword: Nano

Abstract: Electrical tree is a topic that has been extensively studied in recent years. Electrical tree is considered a deterioration of the electrical insulator due to the high voltage field's distortion. Solid insulating materials used in high voltage applications, such as epoxy resin are widely employed due to their high dielectric strength and excellent mechanical properties. This research studies the effect of micro and nanoparticles of Al₂O₃ and SiO₂ on electrical tree inhibition in epoxy resin insulators. Electrical tree inhibition is achieved by incorporating micro and nanoparticles into the polymer material, which possess different properties. Following ASTM D 3756-97, the experiment is conducted with a constant 22 kV voltage and frequency of 50 Hz. Both Al₂O₃ and SiO₂ possess the ability to inhibit the growth of the electrical tree. Experimental results revealed that the addition of Al₂O₃ and SiO₂ to the epoxy resin affected the formation of electric trees. As the quantity of filler increases, fewer electric trees are produced. Additionally, It has an effect on the initial formation time of electric trees. The initial time of the electric tree with the addition of micro/nano(1/3) Al₂O₃ additives at a ratio of 0.1 wt% was 3.5 times longer when compare with pure epoxy resin.

Abstract: Polyamide 66 (PA 66) or Nylon 66 is a strong, easily processed polymer with high thermal resistance and excellent mechanical properties. Tungsten carbide (WC/Co-Cr 86/10-4), known for its exceptional hardness and elasticity, is commonly used for coatings in the thermal spraying and coating industry. In this study, we examined the microstructural, mechanical, and thermal properties of composites made from waste micro and nano WC/Co-Cr 86/10-4 powder and a PA66 matrix. PA66 was reinforced with varying ratios of 3, 6, and 10 wt.% WC/Co-Cr 86/10-4. The composite specimens were created by mechanically mixing granular PA66 and micro and nano WC/Co-Cr 86/10-4 powders and molding them under controlled temperature. Mechanical properties were evaluated through ductility and hardness tests, while thermal properties were determined through DSC analysis. The SEM observation revealed the distribution of WC/Co-Cr 86/10-4 within the polymer matrix. The DSC analysis indicated that the composite had a slightly higher melting temperature than pure PA66, and the thermal conductivity also increased slightly. The experimental results demonstrated that the mechanical properties of the composite improved as the WC/Co-Cr 86/10-4 content increased, specifically in terms of tensile strength and hardness. Additionally, the composite exhibited enhanced interfacial adhesion, mechanical behavior, and thermal properties. This composite, utilizing WC/Co-Cr 86/10-4 waste and recycled PA66, allows for the repurposing of industrial waste.

Abstract: The purpose of this study is to develop ZTA-MgO-MWCNT cutting insert with enhanced properties and excellent tool performance that is suitable for high-speed machining. The effects of MWCNT addition on the physical properties of ZTA-MgO composites were investigated. The samples were fabricated using 80:20 composition (80 wt.% of Al2O3: 20 wt.% of YSZ) with fixed amount of MgO at 1.1 wt.% and MWCNT ranging from (0.1 – 0.5 wt.%) as secondary additives. The CNT was pre-treated in ethanol for 1 hour using an ultrasonic homogenizer before mixing and ball milled with Al₂O₃, YSZ and MgO compositions for 24 hours. The mixture is then pressed at 100 MPa into round-shaped cutting inserts mold after being dried at 100°C for 24 hours. The pressed samples were sintered at 1600 oC for 4 hour soaking time. XRD, density, porosity and shrinkage analysis performed on the samples. The XRD analyses indicate the presence of major phases were α-Al₂O₃, ZrO₂, Zr_0.963Y_0.037O_1.982 and MgAl₂O₄. The effect of MWNT addition on density, porosity and shrinkage of ZTA-MgO shows that density (4.210 g/cm3) and percentage of shrinkage (8.05%) obtained the highest value by 0.2 wt.% MWCNT compared with samples without CNT additives which is only 4.020 g/cm3 and 7.05% respectively. High density value indicates that the shrinkage percentage is also high, which corresponds to the densification of the composites. Poor dispersion of MWCNT within the matrix is highly accounted for agglomeration around Al₂O₃ grain boundaries and decreases in densification.

Abstract: Germanium (Ge) is envisioned as a suitable channel candidate for field-effect transistors (FET). Properties of Ge such as high carrier mobility, compatibility with Si and adaptability with high-k materials makes it comparable to silicon. This paper presents a detailed design of a 30 nm Ge based FinFET by parameter optimization using Silvaco software. Poisson and Schrodinger equation is used to come up with an analytical quantum model. The quantum model is developed based on theory of a double gate (DG) FET but the final design is a trigate (TG) device since they are more scalable. The quantum attributes of DG MOSFET are acquired by adopting the coupled Poisson–Schrodinger equation with the aid of the variational approach. The ratio of channel length (L_C) to fin height (H_fin) to fin thickness (t_fin) is 4:2:1. The channel length is taken as the gate length (L_G) although they are slightly differ mathematically due to side diffusion of the implanted ions. Simulation results show that physical parameters such as dimensions influence electrical characteristics of the device such as threshold voltage (V_TH). Much focus is on optimization of the on/off current ratio (I_ON/_OFF) and V_TH performances. I_ON/_OFF ≈ 10⁶ is achieved at carrier concentration in the range 1 × 10¹⁸ ≤ n_d ≤ 1.22 × 10¹⁸ and in this scenario, V_TH = 0.4V . Systematical investigation is presented using IV characteristics to demonstrate the sensitivity or how critical design parameters of Ge FinFET are to the device’s figure of merits. Device performs well at low voltages but breaks down at higher drain voltages (V_DS ≥ 4V). Gate source voltages (V_GS) range between 0.05V≤ V_GS ≤ 1V and conductance is dependent on it. Effects of DIBL, which is around 0.031, and velocity saturation are studied to determine how they can be suppressed during the design process.

Abstract: Most artificial socket prostheses are applied to fatigue load; therefore, more failure of socket prostheses occur due to fatigue loading. Then, it was necessary to improve the fatigue characterizations of composite materials used to manufacture the artificial socket prostheses by using hybrid nanomaterials, with different types and amounts. So, this work suggested mixing two nanomaterials types to improve the mechanical and fatigue properties of composite materials. Therefore, the experimental work used to manufacture tensile and fatigue samples of composite with different nanoweight fraction effects, in addition to calculating the mechanical properties and fatigue behavior for its composite. There, strength and modulus of elasticity, in addition to, fatigue strength and life evaluating of composite with different nanomaterials mixing. Also, the numerical technique by using the finite element method is used to calculate fatigue life and strength of composite materials. Also, comparison fatigue results were calculated by experimental work with fatigue results evaluated by numerical technique to give the discrepancy for results evaluation. Hence, the comparison of results showed good agreement for the technique used to evaluate the fatigue behavior of composite materials with the nanoeffect, where, the maximum error did not exceed (11.86%). Finally, the results have shown that the reinforcement by mixing two Nanomaterial types lead to improvement in the mechanical properties and fatigue behavior to more than (35%) and increasing the mechanical properties and fatigue behavior to (10%) more than the increase of properties and fatigue characterizations reinforcement by one Nanomaterial type.

Abstract: The ultrafine and nano particles compared to larger particles are gaining high importance because of their vulnerable effects to environment and human health causing respiratory problems, cardiovascular disease, and various types of cancers leading to premature death [1]. WHO report points out that approximately, two thirds of the global burden of disease due to urban outdoor air pollution is mostly from the developing countries in Asia (Cohen et al. 2004)[2]. By number, nearly all of the particles emitted by a diesel engine are nanoparticles which are also true for gasoline engines [3]. This is addressed by new UN Regulations by introducing the emission norms for diesel and GDI vehicles for particle number and PM_2.5 as 6 x 10 ¹¹ and 4.5 mg/km respectively [4]. However, other S.I. engines like CNG, even though they look clean as there is no visible smoke but emitting large number of particles is necessary to investigate. This research paper focuses on characterization of ultrafine and nano particle emissions from CNG vehicle on Indian driving cycle and it covers experimental Investigation to identify the significance of different operating phases viz. idling, acceleration, deceleration and cruising for their contributions to particle number and size distribution pattern over urban as well as on extra urban part of the cycle. CNG passenger car shows large peak of PN emissions during cold starting phase at the beginning of the test cycle which is almost twice that of diesel vehicle. However, this concentration peak will decrease near to 25% on light operating loads during urban part of the cycle, but during acceleration and cruising operation on extra urban cycle under heavy load the PN emissions from CNG car are higher in magnitude. The particles emitted from CNG buses are too small to contribute to PM₁₀ as they are of ultrafine and nano size range.

Abstract: Based on nanometer related theory, this paper has used H68 alloy for power plant condensers alloy surface nano mechanical polishing method, combining the related theory of materials research, the use of metallographic microscopic analysis, XRD analysis, hardness test and electrochemical corrosion test method, the correlation properties of nano surface treatment of H68 test, around the related properties of nano surface treatment H68 experiment, theoretical analysis and normative analysis, combining qualitative analysis with quantitative analysis, it has concluded that the surface nano can improve the corrosion resistance of H68 alloy in ammonia solution.

Abstract: Nano HZSM-5 has been tested in the coupling conversion of methanol and 1-butene reaction together with a micro HZSM-5. The catalysts were characterized with X-ray powder diffraction (XRD), scanning electro microscopy (SEM), N2 isothermal adsorption-desorption, temperature-programmed desorption of ammonia (NH3-TPD) and thermal gravity analysis (TGA). Nano sized HZSM-5 showed higher activity and stability compared to the micro sized HZSM-5.

Abstract: This is a comparative experimental study of the micro, nanoand ultranano-crystalline diamond deposition. The Hot Filament Chemical Vapor Deposition (HFCVD) reactor deposits the films using different deposition parameters. Scanning Electron Microscopy and Field Emission Scanning Electron Microscopy let morphology inspection. Visible-Raman scattering loaded to estimating relative induced stress, by the graphite peak shift and associated with the defect incorporation and sp² bond enhancement. The x-ray diffraction confirmed the diamond crystallinity, where Scherrer ́s equations estimate crystallite size and diamond renucleation rates. In this work we propose a defect increasing relative graphite incorporation with the transition of micro, nanoto ultranano-crystalline diamond deposition. Besides this, we propose that this increase defects follows the increase diamond renucleation rates and decreases in the induced stress films. Included is a discussion of the possible reasons for these observations.

Abstract: Effect of nanoparticles to improve the lubrication load capacity and resistance to extreme pressure of water-based rolling liquid was studied by four-ball tester. Compression experiments were conducted in different lubrication conditions with nanoparticles using Gleeble hot compression simulation machine. Then the residual nanoparticles characteristics and the surface morphology of the compressed sample were analyzed by SEM and EDS. The results show that water-based nanoTiO₂ lubricant can efficiently reduce the friction during metal deformation. nanoZnO is preferred to adhere to metal surfaces and employed to isolate the surfaces. A new lubricating mechanism of nanoparticles in metal hot deformation named convex peak extreme pressure buffering mechanism is thereby proposed, which is verified by the surface morphology of compressed sample.