Recent trend in residual palm oil recovery in a solid state fermentation

Production of palm oil from palm oil mill industries has been facing a serious challenge of overcoming the oil loss as a result of the mechanical extraction process limitations, consequently, leading to economic and environmental impacts. Efforts were made to overcome this impasse by mechanical process, dissolve air flotation, solvent extraction and enzymatic treatment. Most of these methods applied are faced with a somewhat drawbacks. In this review, the various methods of residual palm oil recovery were discussed, while presenting a better method that could allow for optimum recovery with less or no environmental impact via microbial means in a solid state process. Biological process in a solid state condition with fungi such as the white rot basidiomycetes is considered the best for future application, due to the natural availability of the fungi and high degrading capability of lignocellulose biomass. This would significantly be of benefit in terms of abating the huge oil palm mesocarp fiber deposition and aid in meeting the environmental requirement of waste consumption from the source

Gasification of empty fruit bunch for hydrogen rich fuel gas production

A study on gasification of Empty Fruit Bunch (EFB), a waste of the palm oil industry is investigated. The composition and particle size distribution of feedstock are determined and the thermal degradation behaviour is analysed by a thermogravimetric analysis (TGA). Then 300 g h-1 fluidized bed bench scale gasification unit is used to investigate the effect of the operating parameters on biomass gasification namely reactor temperature in the range of 700-1000°C and feedstock particle size in the range of 0.3-1.0 mm. The main gas species generated, as identified by a Gas Chromatography (GC), are H2, CO, CO2 and CH4. With temperature increasing from 700 to 1000°C, the total gas yield is enhanced greatly and has reached the maximum value (~ 92 wt. %, on the raw biomass sample basis) at 1000°C with big portions of H2 (38.02 vol.%) and CO (36.36 vol.%). Feedstock particle size shows some influence on the H2, CO and CH4 yields. The feedstock particle size of 0.3 to 0.5 mm, is found to generate a higher H2 yield (33.12 vol.%) and higher LHV of gas product (17.19 MJ m-3)

The influences of melt-compounding parameters on the tensile properties of low filler loading of untreated-MWCNTs polypropylene (PP) nanocomposites.

This study is to investigate the effects of addition self synthesised multi-walled carbon nanotubes (MWCNTs), to the final properties of polypropylene (PP) matrix nanocomposites. The influences of melt blending parameters were evaluated, where the interrelationship between the temperatures of compounding and roller rotor speed of sh earing blade parameter, to the tensile properties of fabricated composites were studied. MWCNT was synthesised in the laboratory scale; by using the floating catalyst chemical vapour deposition(FC-CVD) method. Pre-compounding work is begun with de-agglomeration of MWCNT which carried out by combining the ultrasonication and mechanical stirrer means simultaneously. Carbon nanotubes produced was first verified by using SEM and TEM imaging microscopy t echniques. It was later integrated with the thermoplastic PP matrix, via melt blending process through internally mixing approach. Very low weight percentage of chemically untreated MWCNT (0, 0.25, 0.50, 0.75 & 1.00 wt. %) was added into PP and later was compression moulded to the thin sheet of composites film. Composites were prepared by varying the compounding temperature into three processing temperature namely 165, 175 & 185°C and also into three shearing speed of roller rotor blade, 40, 60 & 80 rpm respectively. Later, it was mechanically tested via tensile testing following the ASTM D-638 standard method. The interrelationship between each parameter of compounding to the mechanical tensile properties was tested. It was shown that, the additional of very low loading of untreated-MWCNT filler content, does give moderate effects on reinforcement to the tensile properties of composite. Different compounding parameter gives significant difference to the pattern of plot which was comparable between each other

Effects of Ni and TiO2 additions in as-reflowed and annealed Sn0.7Cu solders on Cu substrates

The growth of CuSn and CuSn interfacial layers after isothermal annealing and the resultant effect on the solder joint strength are studied in TiO and Ni containing Sn0.7Cu solders. These composite solders were fabricated using a powder metallurgy method and reflow soldered on a Cu substrate printed circuit board (PCB) with an organic soldering preservative (OSP) surface finish. With TiO additions, a more planar scalloped CuSn morphology was observed with reduced interfacial boundary grooves while a fine scallop-shaped interfacial (Cu,Ni)Sn layer was observed in Ni containing solder joints. The interfacial layer was further suppressed with a combination of Ni and TiO even after annealing which resulted in superior shear strength and fracture energy

Effect of fibre coating and geometry on the tensile properties of hybrid carbon nanotube coated carbon fibre reinforced composite

Hierarchically structured hybrid composites are ideal engineered materials to carry loads and stresses due to their high in-plane specific mechanical properties. Growing carbon nanotubes (CNTs) on the surface of high performance carbon fibres (CFs) provides a means to tailor the mechanical properties of the fibre-resin interface of a composite. The growth of CNT on CF was conducted via floating catalyst chemical vapor deposition (CVD). The mechanical properties of the resultant fibres, carbon nanotube (CNT) density and alignment morphology were shown to depend on the CNT growth temperature, growth time, carrier gas flow rate, catalyst amount, and atmospheric conditions within the CVD chamber. Carbon nanotube coated carbon fibre reinforced polypropylene (CNT-CF/PP) composites were fabricated and characterized. A combination of Halpin-Tsai equations, Voigt-Reuss model, rule of mixture and Krenchel approach were used in hierarchy to predict the mechanical properties of randomly oriented short fibre reinforced composite. A fractographic analysis was carried out in which the fibre orientation distribution has been analyzed on the composite fracture surfaces with Scanning Electron Microscope (SEM) and image processing software. Finally, the discrepancies between the predicted and experimental values are explained. (C) 2013 Elsevier Ltd. All rights reserved

Numerical Study for MHD Stagnation-Point Flow of a Micropolar Nanofluid Towards a Stretching Sheet

In this paper, we investigated the magnetohydrodynamic (MHD) stagnation-point flow of micropolar nanofluid over a stretching sheet. A uniform magnetic field is applied normal to the flow. Nonlinear micropolar nanofluid problem in the presence of the strong concentration of microelements is modeled and then solved by numerical techniques. A parametric study of the involved parameters in the presence of spin gradient viscosity is conducted, and representative set of numerical results is illustrated in the graphical and tabular forms. The complete formulation of the Keller-box method for the considered flow problem is given, and a comparison of the obtained results is performed with the previous published results. The comparison shows that our present results have an excellent match with the previous results in a limiting case. We found that the non-dimensional temperature and its associated thermal boundary layer thickness are enhanced when we use the larger values of thermophoresis and Brownian motion parameter. The non-dimensional concentration is higher for larger thermophoresis parameter but smaller for higher Brownian motion parameter. It is also observed that the smaller values of Lewis number correspond to higher non-dimensional concentration and its associated boundary layer thickness

In vitro antiproliferative and antioxidant activities of the extracts of Muntingia calabura leaves.

The in vitro antiproliferative and antioxidant activities of the aqueous, chloroform and methanol extracts of Muntingia calabura leaves were determined in the present study. Assessed using the 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay, the aqueous and methanol extracts of M. calabura inhibited the proliferation of MCF-7, HeLa, HT-29, HL-60 and K-562 cancer cells while the chloroform extract only inhibited the proliferation of MCF-7, HeLa, HL-60 and K-562 cancer cells. Interestingly, all extracts of M. calabura, which failed to inhibit the MDA-MB-231 cells proliferation, did not inhibit the proliferation of 3T3 (normal) cells, indicating its safety. All extracts (20, 100 and 500 μg/ml) were found to possess antioxidant activity when tested using the DPPH radical scavenging and superoxide scavenging assays with the methanol, followed by the aqueous and chloroform, extract exhibiting the highest antioxidant activity in both assays. The total phenolic content for the aqueous, methanol and chloroform extracts were 2970.4 ± 6.6, 1279.9 ± 6.1 and 2978.1 ± 4.3 mg/100 g gallic acid, respectively. In conclusion, the M. calabura leaves possess potential antiproliferative and antioxidant activities that could be attributed to its high content of phenolic compounds, and thus, needs to be further explored