Papers by Keyword: Seed

Abstract: This study aimed to determine the effect of concentration and immersion time of Salak (Salacca zalacca) Seed extract as a green inhibitor on the corrosion inhibition efficiency and corrosion rate of AISI 1040 steel in a 1M HCl environment. The chemical composition of AISI 1040 steel was confirmed using OES testing to verify its compliance with AISI 1040 chemical standards. The antioxidant activity of the salak (Salacca zalacca) seed extract was determined through the 1,1-Diphenyl-2-Picrylhydrazyl (DPPH) test yielding an IC50 value of 192.55 ppm, indicating weak antioxidant activity. Qualitative phytochemical analysis confirmed the presence of flavonoids and tannins in the extract, as verified by Fourier Transform Infrared (FTIR) testing. The study explored concentration variations ranging from 100 to 500 ppm and immersion time variations of 10 to 30 days were used. The highest inhibition efficiency was obtained at 500 ppm concentration, while the lowest was at 100 ppm, with values of 40.26% and 18.90% respectively. Additionally, the corrosion rate was reduced to 0.035 mm/year at the highest concentration of 500 ppm. These findings demonstrated the potential of salak (Salacca zalacca) seed extract as an eco-friendly, effective corrosion inhibitor for AISI 1040 steel.

Abstract: Polishing of Silicon Carbide (SiC) seed crystals and substrates to achieve an extremely smooth, level surface, and an optically clear finish takes many surface finishing steps with very long processing times producing a significant amount of slurry waste and utilizing numerous lapping and polishing machines. This paper presents a newly developed cost-efficient SiC polishing process which reduces these operations to two surface finishing steps for achieving an optically clear finish on monocrystalline SiC material where the same size of diamond abrasives for lapping and polishing steps allows to carry out stock removal lapping and polishing processes on a single platform (machine) without concern of cross-contamination and making it as a very cost-efficient and high-throughput polishing process for SiC seed crystals and substrates.

Abstract: The SEED (Swirled Enthalpy Equilibrium Device) process was used to produce semi-solid slurries. One of the factors that controls whether or not a slug can be used to produce high quality castings is the solid fraction distribution within the slug, and the solid fraction distribution is strongly dependent upon the temperature distribution. In this study, a model has been developed using ProCAST to investigate the relationship between process parameters and the temperature distribution within slugs. The parameters examined included the heat transfer coefficient between the crucible and slug, the heat transfer coefficient between the crucible and air, the slug diameter, and the initial melt temperature (pouring temperature). It was found that the most important parameters controlling the temperature distribution within slugs were the crucible size and the heat transfer coefficient between crucible and air. Adjustment of other parameters had little influence on the temperature distribution. Processing parameters will be discussed in order to allow the SEED process to be used for the production of large diameter slugs (>100 mm), and for narrow freezing range (0.3<fs<0.5, fs is fraction solid) alloys such as 6063.

Abstract: ZSM-5 has been successfully synthesized by seeding method using coal bottom ash and rice husk as the sources of silica and alumina.Synthesis ZSM-5 were performed by the hydrothermal method in autoclave autogenous at 180 °C for 36 h with molar ratio 10Na : 50SiO : 2Al2O3 : 500H2O with the addition of ZSM-5 commercial as seed. In this experiments, investigated variations seed amounts of 5, 10, 15, and 20% of weight silica. The product was characterized using X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM), and Brunauer-Emmet-Teller (BET). Resulted showed that ZSM-5 succeed formed in all variation of seed contain. At variation seed amount 5%, crystallinity obtained still low in which content of quartz phase still be high. Percent crystallinity highest obtained at the variation of seed amount 20% with the result percent crystallinity relative 106%. The experimental results revealed that phase transformation has occurred, in which an amorphous phase of coal bottom ash and rice husk has been transformed to the ZSM-5 crystal with addition seed as substitution organic template.

Abstract: The known designs of tank for precipitation of aluminum hydroxide from sodium aluminate solution, used in the production of alumina are considered, and the improvement of the design of the precipitator with mechanical mixing is proposed, which allows to intensify the process of precipitation and to avoid strong caustic module of the solution changes.

Abstract: A201 alloy is the strongest cast aluminum alloy, but it is considered one of the most difficult aluminum alloys to cast due to its susceptibility to hot tearing during solidification. Semi-solid casting, which characterizes fine near-globular or non-dendritic grains and relatively narrow solidification range, is potential to reduce hot cracking tendency of alloys. In this present work, semi-solid slurries of A201 alloy were prepared using Swirled Enthalpy Equilibrium Device (SEED) technique and then injected into a self-designed high pressure hot tearing mold. The microstructures of A201 semi-solid slurries with different pouring temperatures were examined. Effects of different casting pressures on the hot tearing sensitivity of A201 have been investigated. This study finds that SEED is capable of producing satisfying A201 semi-solid slurries. Lower pouring temperatures produce A201 semi-solid slurries with finer and rounder grains as well as more uniform microstructure distribution. Increasing the intensification pressure significantly decreases the hot treating tendency of A201 alloy. When the pressure reaches to 90 MPa and the mold temperature of about 250 °C, the hot tearing susceptibility (HTS) index value is nearly zero, which means almost no surface cracks are found in the semi-solid A201 die casting parts.

Abstract: Zeolites posses a high stability, high specific surface area and pores tridimensional system that make them useful to formation of inorganic membranes. During membranes synthesis different parameters should be considered such as nature substrate and the method used in order to obtain a membrane according to its application field. In the present work the formation of a zeolitic layer on the functionalized surface of zirconia substrates was studied. Zirconia disks of ten millimeters of diameter were prepared. They were submitted a chemical functionalization with three different chemical linkers: polyethylenimine (PEI), polydialildimethylamine chloride (PDDA) and 3-aminopropyltriethoxysilane (γ-APS). Subsequently the substrates were submitted to a seeding process, where their surface was grafted with zeolitic crystals corresponding to W zeolite. In order to promote the formation of zeolitic layer the substrates were submitted a hydrothermal treatment with a batch composition similar to that used in the W zeolite synthesis, at 150°C for 48 h. The crystallization products were characterized by XRD and SEM techniques. The results indicated that the chemical linker enhances the formation of a homogeneous zeolitic layer on the substrate and besides acts as structural directing agent allowing to crystallization of a different zeolitic phase to that used in the seeding process, the merlinoite. The morphology, crystalline phase and thickness of zeolitic layer formed on the surface of the substrate depend of the nature of chemical linker used and its interaction with the substrate.

Abstract: A chemical bath deposition (CBD) method was applied to grow zinc oxide nanorod arrays on transparent conductive oxides acting as templates for the synthesis of TiO₂/ZnO nanostructures (TiO₂/ZNR) followed by HCl etching, and then these nanostructures were assembled as anodes in dye-sensitized solar cells. The ZnO nanorods, predominantly grew with good crystallinity along c-axis, exhibit wurtzite structure with smooth surface. Etching of the TiO₂/ZNR by HCl changes the most preferential crystal plane of ZnO from (002) to (100) and significantly increases the atomic ratio of Ti/Zn. Optical absorption measurements indicate a band gap energy of 3.1 eV for ZNR and TiO₂/ZNR. Increasing the spin coating time (SCT) of TiO₂ on ZNR increases the PL intensity. The seed layer number (SLN) of ZnO exerts moderate influence on the photo-to-electricity conversion and an optimum SLN was observed for this study.

Abstract: In flow visualization, the streamline has always been used to display the vector fields, but only using streamlines cannot reveal the nature of flowing intuitively. The dynamic glyphs technology is an important method to show flowing 3D vector fields. However, existing methods of dynamic glyphs are hard to convey the global patterns and local entities at the same time. In this paper, we present a practical method for dynamic visualization of 3D vector fields which combine dynamic glyphs and streamlines, which are rendered respectively according to the information of 3D vector fields. Our method integrates virtues of these two usual techniques, and provides high performance visualization of flowing 3D vector fields directly. Experiments with practical datasets certify that our method could not only depict the local and the global patterns, but more importantly reveal the dynamic nature of flowing 3D vector data.

Abstract: Metal toxicity is an important factor governing germination and growth of plants. We have investigated how Co²⁺ and Ni²⁺ treatment affected germination and early growth stage of oilseed rape (Brassica napus L.). The results showed that the single pollution of Co2+was capable to stimulate the seed germination and seedling growth of oilseed rape at lower concentration, but the phenomena did not exist by the single pollution of Ni2+. Not only polluted by Co2+ but also by Ni2+, all indexes of germination and growth reduced gradually at higher concentration among examined concentration of heavy metals. Meanwhile, effects of Ni2+single pollution were stronger than that of Co2+single pollution.