Abstract: Polyaniline-zinc oxide composite on Kapok paper were fabricated for methylene blue dye removal in aqueous solution. Kapok fibers were fabricated into papers. The fabricate paper served as substrate for the zinc oxide-polyaniline composite. Zinc oxide particles were deposited on the Kapok paper using an in-situ method while polyaniline molecules are deposited on paper using Successive Ionic Layer Adsorption and Reaction (SILAR) method. The polyaniline molecules were deprotonated using sodium hydroxide (NaOH) to be able adsorb cationic dyes in aqueous solution. The samples were characterized using scanning electron microscope (SEM), energy dispersive X-ray (EDX) spectroscopy and Fourier transform infrared (FTIR) spectroscopy. Results show that the deprotonated polyaniline nanocomposite was able to remove at about 75% more dye compared to the as-synthesized polyaniline nanocomposite.
Abstract: Based on the special designed fluorinated hollow polymeric spheres, the practical research of their evaporation control is studied in a horizontal oil tank. The hollow spheres could float on the surface of fuel oil, which is proved as an effective method to resolve the evaporation loss problem. Compared with the oil tank without hollow spheres, the evaporation control method would reduce as much as about 73.1% fuel evaporation loss in practical experiments. The results suggest a potential significant application of the evaporation control method in the fields of the fuel storage and transport.
Abstract: Titanium alloy, Ti-6Al-4V is a popular alloy used in wide range of design applications mostly in aerospace and biomedical industry due to its advantageous material properties. This research is based on threading operation in a cylindrical workpiece of Ti-6Al-4V additive manufactured by Selective Laser Melting (SLM) technique. Secondary machining is described as the operations that are performed on the workpiece after a primary machining in order to achieve a required finish and form. Common secondary operations after drilling includes threading, reaming and knurling. Threading is a significant machining process in almost all applications of Titanium alloys. The development of an efficient threading process for Titanium alloys and enhancing existing methods may lead to a wider application of additive manufactured Titanium alloys. The aim of this research is to find out favorable threading conditions for Titanium alloy Ti-6Al-4V to obtain better machinability. Threads are tapped into the workpiece using variable machining parameters such as spindle speed and depth of cut. Statistical data are collected and analyzed by qualitative and quantitative evaluation of the threads. The outputs under consideration to evaluate efficiency of the secondary machining include surface texture (roughness (Ra)), dimensional accuracy (thread geometry) and power required (cutting force).
Abstract: This work investigated the influences of cutting speed and feed rate on surface roughness in hard turning of AISI 4140 chromium molybdenum steel bar using mixed ceramic inserts Al2O3+TiC under dry condition for automotive industry applications. Turning experiments were conducted by varying cutting speed ranging from 150 to 220 m/min and feed rate ranging from 0.06 to 1 mm/rev. General factorial design was used to analyze the data set of surface roughness and determine statistically significant process factors based on analysis of variance results. The results showed that average surface roughness was significantly affected by feed rate and interaction between cutting speed and feed rate at the level of significance of 0.05. An optimal operating condition for hard turning of AISI 4140 with the ceramic cutting tool that produced a minimum machined surface roughness was obtained at cutting speed of 220 m/min and 0.06 mm/rev.
Abstract: In this article, a study is presented of the effect of the focusing ratio (FR) on the line geometry in aerosol printing process. The FR was defined as the ratio of sheath flow to aerosol flow. The FR was varied from 1 to 20. In the experiment, different nozzles were used, with outlet diameter of 100, 150 and 300 μm. It was established that in increasing FR from 1 to 20 by reducing the aerosol flow with constant sheath flow rate, line width and thickness are reduced in more than 40 and 10 times respectively. It is also found that by increasing the FR from 2 to 8 by changing only sheath flow with constant aerosol flow rate, line width is reduced from 125 to 75 μm, while line thickness is increased from 7.1 to 10.3 μm. It is shown that this feature is related to the quantity of the matter deposited on the substrate, which is directly related to aerosol flow. The achieved result is important for designing current-carrying lines of electronic circuits which require a specific aspect ratio and high circuit element density
Abstract: This paper shows part orientation issue in the process of Selective Laser Melting (SLM) at four examples of metallic materials (Fe, stainless steel 316L, TiAl6V4 alloy and AlSi11Mg alloy). Horizontally and vertically oriented samples differ in their mechanical properties, especially in plasticity. The causes of these differences are related to a thermal history, microstructural features and porosity. Depending on a particular material, individual effects are manifested under different extents.
Abstract: Powder rolling is used for manufacturing long-length strip. For obtaining the product with high green density it is necessary to ensure shear strain in the deformation zone. Based on the principles of technologic adaptation the dual roll closed caliber with adaptively changed rigidity was constructed. It consists of upper bandage with shoulder, bottom bandage with groove in which the set of three rings (two aside and one central) is located. The pass is arranged by aside rings and outside surface of the central ring forming closed caliber while interacting with the shoulder of the upper bandage. The caliber output is equal to zero and the broadening at rolling is fully excluded. Such construction of the tool makes it possible to achieve high level of hydrostatic stress of tensor simultaneously with intensification of shear strains resulting in practically nonporous rolled strip. Taking into consideration peculiarities of calibre rolling the new criterion was proposed. This criterion enables to characterize roll system for each material, incompact materials in particular, considering retraction ability, to assess and identify the final square of the rolled material at different caliber configuration. Dependence of maximum value of powdered rolled strip thickness on dual roll closed caliber retraction surface value at different rolled strip width is presented.