Effect of thermal ageing on the scratch resistance of natural-fibre-reinforced epoxy composites

In this study, the effects of thermal ageing on the scratch‐resistance properties of natural‐fibre‐reinforced epoxy composites were investigated. Jute, kenaf and hemp‐fibre‐reinforced epoxy composites were fabricated using the vacuum infusion method. The natural‐fibre‐reinforced composites were exposed to thermal ageing for 7, 15, and 30 d at 90 °C temperature. Scratch tests were carried out using a CSM Revetest Xpress machine. The scratch resistance properties, such as the critical normal load, coefficient of friction, penetration depth, fracture toughness, scratch hardness, and scratch tearing were determined after thermal ageing. The results demonstrate that the scratch resistance of the composites decreased as the thermal ageing time increased. However, the jute‐fibre‐reinforced epoxy composites had the highest critical normal load, fracture toughness and scratch hardness compared to those of kenaf and hemp‐fibre‐reinforced epoxy composites after 30 d of thermal ageing

Compressive and flexural strength of concrete containing palm oil biomass clinker and polypropylene fibres

This paper presents the effects of using palm oil biomass (POB) clinker with polypropylene (PP) fibres in concrete on its compressive and flexural strength performances. Due to infrastructural development works, the use of concrete in the construction industry has been increased. Simultaneously, it raises the demand natural sand, which causes depletion of natural resources. While considering the environmental and economic benefits, the utilization of industrial waste by-products in concrete will be the alternative solution of the problem. Among the waste products, one of such waste by-product is the palm oil biomass clinker, which is a waste product from burning processes of palm oil fibres. Therefore, it is important to utilize palm oil biomass clinker as partial replacement of fine aggregates in concrete. Considering the facts, an experimental study was conducted to find out the potential usage of palm oil fibres in concrete. In this study, total 48 number of specimens were cast to evaluate the compressive and flexural strength performances. Polypropylene fibre was added in concrete at the rate of 0.2%, 0.4% and 0.6%, and sand was replaced at a constant rate of 10% with palm oil biomass clinker. The flexural strength of concrete was noticed in the range of 2.25 MPa and 2.29 MPa, whereas, the higher value of flexural strength was recorded with 0.4% polypropylene fibre addition. Hence, these results show that the strength performances of concrete containing POB clinker could be improved with the addition of polypropylene fibre

Subcellular Location, Phosphorylation and Assembly into the Motor Complex of GAP45 during Plasmodium falciparum Schizont Development

An actomyosin motor complex assembled below the parasite's plasma membrane drives erythrocyte invasion by Plasmodium falciparum merozoites. The complex is comprised of several proteins including myosin (MyoA), myosin tail domain interacting protein (MTIP) and glideosome associated proteins (GAP) 45 and 50, and is anchored on the inner membrane complex (IMC), which underlies the plasmalemma. A ternary complex of MyoA, MTIP and GAP45 is formed that then associates with GAP50. We show that full length GAP45 labelled internally with GFP is assembled into the motor complex and transported to the developing IMC in early schizogony, where it accumulates during intracellular development until merozoite release. We show that GAP45 is phosphorylated by calcium dependent protein kinase 1 (CDPK1), and identify the modified serine residues. Replacing these serine residues with alanine or aspartate has no apparent effect on GAP45 assembly into the motor protein complex or its subcellular location in the parasite. The early assembly of the motor complex suggests that it has functions in addition to its role in erythrocyte invasion

Effect of extrusion ratio on paraffinic mineral oil lubricant in cold forward extrusion

A finite element (FE) analysis is made for steady-state two-dimensional forward extrusion with three different extrusion ratio values. Predicting extrusion force of aluminum billet extruded with palm oil lubricant will definitely be helpful in deciding the right extrusion ratio. Hence, the finite element method was applied to investigate the influence of extrusion ratio on palm oil lubricant. The extrusion ratios evaluated were 1.5, 2, and 3. The reference of the study was in accordance to the experiment results of 0.1 mg paraffinic mineral oil grade 95 (Pr95) with kinematic viscosity of 90.12 mm(2)/s at 40 degrees C for the extrusion ratio of 3. The result was found to be reliable once the FE model was validated by the established work. The extrusion force for each extrusion ratio was described and evaluated. The FE analysis also accounts for plasticity material flow and equivalent plastic strains in the deformation region. The analysis agreed that the extrusion ratio of 1.5 reduced the extrusion force compared to the extrusion ratio of 2 and 3. This was confirmed by the plotted equivalent plastic strain deformation which shows that the high value of equivalent plastic strain near the extrusion die surface was decreased. As a result, the extrusion force becomes greater with the increasing of extrusion ratio

Biodegradability of bioplastic film using different regions of Pennisetum purpureum incorporated with gelatine and chitosan

The accumulation of plastic waste and rapid reduction of fossil reserves have pushed the development of packaging towards eco-friendly materials, such as bioplastics. However, most bioplastics are manufactured with chemical additives that are inorganic and entirely nondegradable. Therefore, bioplastics from renewable and biodegradable sources have been developed by incorporating cellulose, gelatine, and chitosan. This paper presents the optical properties, moisture content, swelling behaviour, assessment as packaging materials, and biodegradability tests of bioplastics. The considered bioplastics consisted of raw and cellulose from the whole, fibre, and bark of Pennisetum purpureum, with gelatine and chitosan fabricated using the solution-casting method. Cellulose was isolated using 8 wt% concentration of sodium hydroxide followed by 1.7 wt% concentration of sodium chlorite. The compatibility of fibre-matrix adhesion was improved by including cellulose from WPP, FPP, and BPP into the incorporation of chitosan and gelatine in bioplastics. Nevertheless, improving their optical properties, moisture content, and swelling behaviour had caused bioplastics to be more resistant to microbial activity and have the slower degradation rate

The effect of lubricant viscosity in cold forward plane strain extrusion test

The effect of lubricant with three different viscosities was investigated by plane strain extrusion experiments and visioplasticity analyses. The lubricant is additive free paraffinic mineral oil. VG30 is a low viscosity lubricant with kinematic viscosity of 32 mm 2 /s at 40ºC. VG95 is a medium viscosity with kinematic viscosity of 92 mm 2 /s at 40ºC. VG460 is a high viscosity with kinematic viscosity of 462 mm 2 /s at 40ºC. The experiment used a cold work plane strain extrusion apparatus consist of a pair of taper die and a symmetrical workpiece (billet). The billet material was annealed pure aluminum A1100. The experiments were conducted at room temperature. The experimental results are focusing on the extrusion load, billet surface roughness, billet surface and grid pattern observation. The distribution of velocities and effective strain on the sliding plane of taper die were analyzed quantitatively, by using the visioplasticity method. From the results, low viscosity lubricant would give high extrusion load, however, low viscosity lubricant could produce product surface with low surface roughnes