Abstracts:This research presents two type of cactus (Opuntia ficus-indica) (natural cactus (NC) and dried cactus (DC)) as a biological adsorbent, evaluated for the effectiveness of hexavalent chromium Cr(VI) removal from artificially contaminated aqueous solutions. The characterization of the biosorbents were made using different techniques such as X-ray Fluorescence (XRF), Fourier transform infrared (FTIR) and Scanning Electron Microscope (SEM) to better understand the adsorption mechanism-property relationship. Adsorption kinetics showed that the adsorption behavior followed the pseudo-second-order kinetic model. The adsorption isotherms fitted by the Langmuir model showed that the highest Cr(VI) adsorption capacities using natural cactus and dried cactus are 21.19 and 2.63mg/g respectively. Additionally, various physiochemical parameters such as contact time, adsorbent dosage, pH and temperature were investigated in a batch-adsorption technique. The results illustrated that the cactus have significant potential as economic, safe and effective adsorbent materials for the Cr(VI) adsorption from the aqueous solution.

Abstracts:Recent interest by automotive manufacturing company is to develop a component, capable of enhancing safety features associated with lightweight materials such as using aluminum and composites. The use of aluminum metal matrix composites (MMC) and composite materials improve the performance of an automotive crash box due to their lightweight. Automotive crash box is a component, equipped at the front end of a car, and is one of the most important devices for crash energy absorption. The review is mainly divided by two topics, i.e. design of geometry profiles and the crash box material advancements, both geometry and material properties would influence the efficiency of kinetic energy absorption during collision. This review benefits both academics and corporate sector as it outlines major lines of research in the crash box design. It discusses the results from 3D simulations up to laboratory experiments of crash box specimen and the effect of material selection to the characteristic of crash box device. The information from this paper should stimulate more research and more crash box design solutions to reduce fatal damage during collision in automotive industry.

Abstracts:Natural fibres, nowadays; have become the matter of discussion in the research field amongst various scientists to inculcate it in the formation of composites instead of production of composites using synthetic fibres like glass, carbon and aramid. This is due to various advantages associated with natural fibres like eco-friendly, low cost, availability in abundance and its bio-degradability. Lots of work has been carried out in the production of natural fibre reinforced polymer composites, using natural fibres like jute, hemp, cotton, sisal, kenaf, bagasse, areca, abaca, bamboo etc. and their properties have been studied. Here is an attempt made on the literature survey of areca fibre reinforced polymer composites where different properties of areca fibres, its maturity level, surface treatment effect on properties of fibres, composite formation with different matrices, its mechanical properties, thermal and acoustic properties related to different composites has been highlighted.

Abstracts:Medium density fiberboard (MDF) is one of the wood composites which are used widely in the furniture industry. Therefore, its strengthening is required. Sandwiched material is manufactured by inserting sugarcane bagasse medium density fiberboard between the glass fiber reinforced laminates in just the same fashion as a sandwich. A hand lay-up technique is used to prepare the sandwiched specimen, in which the medium density fiberboard plate is put in between two woven layers of glass fiber epoxy laminates. Tensile and bending tests are done to investigate efficiently the tensile and flexural behaviors for the MDF strengthening process. In addition, compact tension and center notch specimen tests are carried out to obtain the effect of the modification performed for the MDF main material on fracture toughness. Moreover, a water soaking test is held out, and fungal bioassay resistance is investigated to obtain some of the novel material environments. The results illustrate that both tensile and flexural strength are extremely modified and increased. Besides, the results show compatibility and bonding between layered material and medium density fiberboard plate. The fracture toughness is greatly increased, and both tests can be met as regards fracture toughness tests for such novel composite material. The novel material has high resistance to fungal creation, which helps it to be utilized in medical furniture. Finally, it is found that only a very little percentage of absorption is established for the novel produced material.

Abstracts:Geopolymers were synthesized using metakaolin obtained from the waste of white paper pulping process. The waste is mainly composed by cellulose, calcium carbonate and kaolin. Chemical and physical procedures were conducted aiming to separate its components and obtain metakaolin. The cellulose was eliminated by burning the waste at 450°C. The CaCO3 was removed by reacting the material with a 1.8M HCl solution. The purified kaolin went through heat treatment 850°C for 2h, in order to be transformed into metakaolin by dehydroxylation. Geopolymers were produced to assess the performance of the resulting metakaolin. The aluminosilicate alkaline activation was executed using four solutions - composed of 8M and 12M of KOH and NaOH, each combined with Na2SiO3 in a 2:1 fixed ratio. The results pointed out that the metakaolin obtained from the waste treatment was a quality one, enabling it to be applied in the development of geopolymers.

Abstracts:The aim of this work was the development (design, construction and tests) of a Three-phase Synchronous Machine with permanent magnets and four poles to be used in small wind turbines, where the rotor and stator cores, usually constructed from laminated steel sheets, were replaced for massive blocks obtained from the Powder Metallurgy (PM) process. The other parts of the machine, such as housing, shaft, bearings and covers, were obtained from conventional three-phase induction motor of 10 HP. Initially, it was studied sintered alloys from pure iron, Fe-Si, Fe-P and Fe-Ni; eventually these alloys were analyzed in terms of magnetic and mechanical properties as well as electrical resistivity. From this study, it was chosen the use of sintered pure iron for the construction of the rotor and Fe1%P for the construction of the stator. The permanent magnets used were Nd-Fe-B, and the windings calculation was based on the coiling of the three-phase induction motor. According to the tests performed, it was observed the generation of a three-phase sinusoidal wave voltage of 242 VRMS, and the yield of 40.8%.