Papers by Keyword: Spherical

Abstract: The present study explores the green conflation of manganese dioxide (MnO₂) nanoparticles through a simple, Eco-friendly, and cost-effective system. This conflation process involves the response of potassium permanganate with an waterless splint excerpt of Hibiscus rosa- sinensis, serving as both a reducing and stabilizing agent. The green conflation system is profitable as it avoids poisonous chemicals, making it safer for both the terrain and implicit operations. The synthesized MnO₂ nanoparticles were considerably characterized using colorful logical ways. X-ray diffraction (XRD) analysis was used to confirm the liquid structure, while Fourier- transfigure infrared (FT- IR) spectroscopy handed sapience into the functional groups present in the material. UV-Visible spectroscopy was employed to study the optic parcels and band gap of the synthesized nanoparticles. Morphological details were observed through Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), which revealed the nanoparticles in globular shape and nanoscale size. One of the notable findings of this study is the photocatalytic effectiveness of the synthesized MnO₂ nanoparticles. Under visible light irradiation, these nanoparticles effectively degraded methyl orange color in waterless results, showcasing their eventuality as an effective photocatalyst. also, the synthesized MnO₂ nanoparticles demonstrated promising operations in the junking of organic adulterants from water, emphasizing their environmental significance. Overall, this study contributes to the development of sustainable nanomaterials for environmental remediation, particularly for wastewater treatment operations. The green conflation approach, combined with the excellent catalytic parcels of MnO₂ nanoparticles, underscores the material's eventuality for practical and large- scale operations.

Abstract: The performance of bracket component is low with uneven micro-structure, internal porosity and shrinkage defects produced by traditional liquid die casting process which cannot be strengthened by T6 heat treatment. In this paper, the aluminum alloy bracket with high-performance and light weight was prepared by a novel semi-solid slurry preparation technique that included chilling rod stirring and funnel-shaped cylinder device, which rapidly reducing the liquid temperature to near liquidus and realizing explosive nucleation. The effects of pouring temperature and CRS process on the microstructure and mechanical property of bracket were studied by optical microscopy (OM) equipped with polarizing mode and bench failure test. The results show that the as-cast microstructure mainly consists of near-spherical α-Al. And the semi-solid micro-structure was affected by these two critical parameters, the pouring temperature and CRS process. Without the condition of stirring, the micro-structure is typical dendritic with a certain proportion of fine spherical crystals, which was mainly generated during the filling of die casting process. And with the addition of the chilling rod, the finer and more uniform spherical semi-solid micro-structure was obtained with the lower pouring temperature. Based on the above semi-solid process and flow controlling through the mould design and vertical die casting process optimization, the high-performance bracket component without shrinkage can be prepared. Additionally, compared with the liquid die casting process, the internal quality and bench testing force of bracket prepared by CRS vertical die casting process are significantly improved.

Abstract: The method for the formation of a spatial construction of a hemispherical dome in the form of an icosahedral-type 320-gon is considered. The description of pentagonal pyramidal fragments, included in the structure of the dome frame, is described. Constructive solutions of nodal connections of the dome core rods are presented. The results of the design are shown in the illustrations.

Abstract: Highly stable silver nanoparticles synthesized in single-step green method by mixing silver nitrate and aqueous extract of Almond (Prunus amygdalus). Experiments were conducted to influence the change in the silver nitrate concentration and time on the synthesis of silver nanoparticles at room temperature under dispersed sun light. The almond extract acted both as the reducing and stabilizing agent for the synthesis of silver nanoparticles. The change in the color of the reaction mixture was monitored using UV-Visible spectrometry whereas particles synthesized were characterized using Scanning Electron Microscopy, Dynamic Light Scattering and Fourier Transform Infrared Spectroscopy. The synthesized nanoparticles were almost spherical in shape with an average size about 20 nm and they exhibited bacteriostatic property against E. coli.

Abstract: The precursor Ni (OH)₂ was synthesized by a simple hydrothermal method with hexamethylenetetramine ((CH₂)₆N₄) as precipitant and template, and then NiO was gained after calcination. The phase and morphology of the synthesized product were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), and the electrochemical capacitive characterization was performed using cyclic voltammetry (CV), chronopotentiometry and electrochemical impedance spectroscopy (EIS) in a 6mol/L KOH aqueous solution electrolyte. The result shows that spherical NiO without impurity was synthesized, the average diameter of the spheres is 5 um and these spheres were constructed by the interactive arrangement of many nanoflakes in three dimensions. This kind of NiO shows the typical electrochemical characteristics of pseudo capacitance with high specific capacity and excellent rate capability. The specific capacity can reach 515F/g at the current density of 1A/g

Abstract: With the requirements of machining develop towards high precision, high efficiency, intelligentization, combination and greenization, in this paper we develop a NC spherical turning and grinding machine tool with high precision and combination to meet the brisk demand of market for spherical workpieces with large diameter and high precision. According to the enterprises’ practice results ,our machine tool can finish machining of large diameter and high precision sphere quickly, with high quality and low cost, and it has a high practical value.

Abstract: An investigation of the drying of spherical food particles was performed, using peas as the model material. In the development of a mathematical model for drying curves, moisture diffusion was modelled using Fick’s second law for mass transfer. The resulting partial differential equation was solved using a forward-time central-space finite difference approximation, with the assumption of variable effective diffusivity. In order to test the model, experimental data was collected for the drying of green peas in a fluidised bed at three drying temperatures. Through fitting three equation types for effective diffusivity to the data, it was found that a linear equation form, in which diffusivity increased with decreasing moisture content, was most appropriate. The final model accurately described the drying curves of the three experimental temperatures, with an R² value greater than 98.6% for all temperatures.

Abstract: Spherical bismuth titanate (Bi₄Ti₃O₁₂) particles were synthesized by hydrothermal method using Bi(OH)₃, Ti(SO₄)₂ and KOH as raw materials, using polyvinylpyrrolidone (PVP) as the surfactant. The effects of concentration of the alkali solution, the reaction temperature and soaking time on the bismuth titanate crystal structure and morphology have been analyzed. XRD, SEM were used to characterize the crystal structure and microstructure of the as-prepared Bi₄Ti₃O₁₂.The results show that the temperature plays an important role on the morphology of the Bi₄Ti₃O₁₂.As the increase of the hydrothermal temperature, the Bi₄Ti₃O₁₂ has been transformed from the spherical morphology to fibrous morphology. The spherical Bi₄Ti₃O₁₂ powders with uniform distribution can be obtained when the concentration of KOH is from 1mol/L to 2 mol/L,the reaction temperature and hydrothermal time are 160°C and 24h respectively. SEM observation showed that the diameter of spherical Bi₄Ti₃O₁₂ is about 500 nm.

Abstract: Due to the practical problems nowadays that the duty cycle is small and the utility rate of solar energy is low of photoelectric sensor light sensitive array, and having analyzed the advantages on solar energy utilization of square aperture spherical micro-lens than traditional circular aperture micro-lens array, we conduct a research on the fabricating of square aperture spherical micro-lens and testing technology. With the help of light spread theory, we analyses the relationship between light amplitude distributing rules, exposure length and exposure energy, establish a mathematical model of light distributing rules and use computer software to emulate the model. The results indicate solar energy distributes regularly in adhesive film. If the energy is fixed, exposure length will gradually become saturated following time. At the same time, we fabricate infrared quartz micro-lens array with array 256×256, single element lens 40×40μm, spherical radius 60μm, single element spacing 1μm.The experiment data are the same as emulation results.

Abstract: The expression for the elastic field of an expanding spherical inclusion in an infinite isotropic elastic medium is presented. The influence area of a supersonically expanding spherical inclusion is given in the form of expressions and graphs. And the difference of the influence area between supersonic expansion and subsonic expansion of a spherical inclusion is discussed.