×
The submission system is temporarily under maintenance. Please send your manuscripts to
Go to Editorial ManagerMagnesium oxide nanoparticles were deposited by laser pyrolysis process. Three types of lasers were employed CW CO2, Q-switched Nd-YAG (short pulses) and long pulses Nd-YAG lasers. The size and density of nanoparticles vary with laser energy, power, pulse duration and the scanning speed of the laser. In this method, MgO nanoparticles were deposited by a laser beam on a quartz substrate from aqueous solution of magnesium nitrate. AFM images reveal formation of small nanoparticle size of 24.5 nm with surface roughness 6.97nm by Q-switched Nd-YAG laser (10 ns) when the energy was 1J. While for CO2 laser, the smallest size was 18.8 nm at 0.4mm/s scanning speed with surface roughness 5.21nm at the same scanning speed. Moreover, long Nd-YAG pulses laser produces relatively larger average size of 37.5nm at 0.8ms pulse duration. The absorption spectra from UV-Visible spectroscopy were also conducted. The best absorption intensity was obtained at a wavelength ranging between 420-430 nm for both lasers. Finally, Thermal analysis using COMSOL Multiphysics software for the deposition process reveals that maximum temperature about 440Kfor Q-Switched Nd-YAG laser at 1J laser energy. While for RF CO2 laser, the maximum temperature obtained at 0.4mm/s scanning speed is 850K.This work provides a good knowledge for the deposition of nanoparticles using laser beams.
Improvements in the thermo-physical properties of Phase Change Materials (PCM) caused by nanoparticle dissipation are critical for a wide range of technologies. The current study describes numerically the investigation of the charging and discharging process of paraffin wax dispersed with different concentrations (1%, 3%, 5%, 7%, and 10% ) of Alumina nanoparticles (Al2O3), in a Single Thermal Energy Storage (STES) system. For this study, a time-dependent, two-dimensional simulation of the solidification and melting process was performed numerically for different velocities. The study is realized using the CFD ANSYS FLUENT software package (Version 18) that employs the phase-change phenomenon using the enthalpy technique. The results show that adding alumina nanoparticles to paraffin wax reduces the melting and solidification process, and raising nanoparticle concentration accelerated the melting and solidification process even more when compared to pure paraffin wax. The greatest improvement was obtained with the maximum concentration of nanoparticles with total time saving between (12% - 11.76% ) in the charging process and between ( 15.71% - 19.60% ) in the discharging process depending on velocity. Furthermore, other important findings were that the presence of nanoparticles makes a little effect in the early stages of the solidification and melting processes, but as time passes, the rate of solidification and melting rises. Comparison with previous works gave good agreement of about 34%.
The effect of metal nanoparticles (MNPs) on the electric field strength and distribution for improvement solar cell performance is investigated and simulated. By manipulating the properties of nanoparticles, distribution of the electric field was altered. In this paper, classical solar cell (p-n junction) and improved structure (add an extra layer of SiO2 and gold nanoparticles on the top of p-n junction) is simulated. Different sizes of NPs, thickness of SiO2 sublayer, and spacing distance between NPs is done to improving the electric field and showing plamonic effect. Gold NPs deposition on single crystalline silicon solar cell is modelled by COMSOL 5.2 2D, Electromagnetic wave propagation in the frequency domain with periodic boundary conditions. The best wavelength found in our work is 550 nm. The electric field enhances when the size of NPs increases but it must be limited. When gold NPs are deposited on the SiO2 sublayer, the plasmonic effect appears due to decreasing the refractive index. Moreover, separation distance between NPs affect the electric field enhancement by manipulating the number of NPs, the distance decreases and the plasmonic interaction appears.
In this work, environmentally friendly zinc oxide nanoparticles was produced using sustainable green technology. With several loading amounts, such as 5%, 10%, 50%, and 100%, the banana peel extract was utilized as a capping agent. This was followed by calcinations at 400 ºC for 3 h in a muffle furnace. To evaluate the physical and chemical change of the synthesized nanoparticles, XRD, FTIR, UV-VIS and SEM/EDAX was used. The characterization results reveald that the all the green synthesized ZnO NPs samples strongly supports the well-crystallinity with high phase purity. The average crystallite size of the prepared samples was calculated using Debye-Scherer's formula and the results shows that with an increase in extract amount, the average crystallite size was shrinking. The FTIR result verified the successful chemical reaction between zinc salt and banana peel extract. The UV-VIS results showed the effect of size quantisization phenomena at 100% extract adding. Finally, the SEM images for all the prepared samples confirm the spherical shape.
The mixing technique was applied in this study to enhance the strength performance of the cement. The addition of 3% by weight of hydroxyapatite (HA) nanoparticles were mixed with 97% polymethyl methacrylate (PMMA) acrylic polymer, which has a nano size to serve as the matrix material. The surface roughness and continuous porosity of the bone cement were found to be slightly increased by the incorporation of nanoparticles, which enhanced bone-implant osseointegration and ingrowth. Atomic force microscopy (AFM) analysis revealed that the addition of hydroxyapatite (HAp) nanoparticles resulted in a surface roughness value (Sa) of 16.25 nm, which is similar to that of natural bone. The energy-dispersive X-ray spectroscopy (EDS) mapping results discover precentor material and uniform distribution. The Sample exhibited promising results in the antibacterial test, showing efficacy against bacteria both with and without sterilization, confirming its antibacterial properties. The mechanical tests conducted on the sample, including tensile, compression, bending and Vickers hardness tests, yielded favorable results and indicated that the sample is suitable for its intended application. In the theoretical works the design of the bone, screw, and bone plate was conducted using SolidWorks, followed by an analysis using ANSYS under both axial and bending load conditions. The theoretical analysis revealed that the safety factor was less than 1 when an axial load of 13 N was applied and a bending load of 2 N was applied, indicating that the structure may not be able to withstand these loads safely. Under both ambient and physiologically relevant conditions in the human body, HA and PMMA have demonstrated to be excellent choices for enhancing the clinical performance of bone cement. This, in turn, can lead to increased longevity of implants, decreased patient risk, and lower healthcare costs
In recent years, nanoparticles have gained significant attention in the field of cancer treatment due to their extensive potential and wide range of uses. The research mostly focuses on the inorganic chemicals, with a specific emphasis on metals, in order to enhance the comprehension of functional nanoparticles synthesis. This undertaking is motivated by the distinctive characteristics exhibited by these materials, which provide significant advantages for both fundamental scientific inquiry and practical implementations, notably those focused on cancer. The objective of this review is to conduct a comprehensive analysis of the diverse applications of nanocomposites, with a specific focus on their utilization in medication delivery.
Surface reconstruction of silicon using lasers could be utilized to produce silicon nanostructures of various features. Electrochemical and photoelectrochemical etching processes of silicon were employed to synthesize nanostructured surface. Effects of current densities 5, 10 and 20 mA/cm2 on the surface features were examined. It is found that the surface porosity and layer thickness increase with the current density. Moreover, large surface area of 410 m2/cm3 can be achieved when laser power density 0f 0.6 W/cm2 was used during the etching process. Optimum operating conditions were found to achieve better silicon nanostructured surface features. The surface roughness can be reduced to 8.3 nm using laser beam of 650 nm irradiated the silicon surface during the photoelectrochemical etching process. The surface morphology of the nanostructured silicon surface using SEM and AFM could give rich details about the surface. Silver nanoparticles of 10 – 20 nm was embedded at the nanostructured silicon surface by LIFT process to reduce the surface resistance and maintain the large surface area. This technique enables silicon nanostructures to be efficiently used in many optoelectronic applications.
Orthoses and prostheses were Chosen and laminated based on their high Yield, ultimate stresses, bending stresses, and fatigue limit. Response Surface Methodology (RSM) was utilized to find the best values for two parameters reinforcement perlon fiber and percent of Titanium Nanoparticle coupled with the matrix resin during optimization. The response surface methodology combined the expertise of mathematicians and statisticians to construct and analyze experimental models. Using this method, we identified 13 different lamination samples comprising a wide range of perlon number and Ti nano Wt% in their Perlon layer composition. All lamination materials defined by RSM methods and produced by a vacuum system were subjected to a battery of tests, with fatigue tests performed on the ideal laminating material in contrast to laminations created in the first study (Tensile test, Bending test, and Fatigue tests according to the ASTM D638 and D790 respectively). In comparison to the other 12 laminations tested using Design Expert version 10.0.2, the lamination with ten perlon layers and 0.75 percent Ti nano proved to be the strongest overall in terms of Yield, ultimate, and bending loads. This study used composite materials and titanium nanoparticles to characterize and fabricate ankle foot orthoses. Strength in bending should amount to about 70 MPa, around 85 MPa in tensile tension. Two empirical quadratic equations for the models of peak bending strength and maximum tensile stress with 95% confidence were created using the response surface approach and analysis of variance within the design of experiments software.
Enhanced signal emission from nano (ESEN) coated titanium target over than that from normal untreated one was investigated. Four samples of Ti alloy were adjusted, the first sample was left untreated, the second and third samples were coated with plasma sputter at thicknesses of 35nm and 70nm, and the last sample was treated with a drop of colloidal Au nanoparticle solution prepared by laser ablation. The (ESEN) was monitored with Ti at 413.7 and 393.3 nm. It was obtained that the spectral emission from the nano-laser ablation had a greater improvement than that from the plasma sputter coating or bulk target. Enhancement factors were found up to ten folds, and show the spectroscopic line induced patterns by laser energies (100,150, and 200mJ) from the alloy with and without gold.