W. B. Wan Nik

Friction Characteristics of RBD Palm Olein Using Four-Ball Tribotester

In this study, the effect of load on the tribological performance of RBD palm olein is investigated using a four-ball wear tester according to the standard test of ASTM D4172. Tests were conducted with 40, 60, 80, 100 and 120 kg normal loads. The experimental temperature and rotational speed were held constant at 75 °C and 1200 rpm, respectively. The test duration was 60 minutes in all cases. For each load, the tribological properties of RBD palm olein were compared with the properties of additive-free paraffinic mineral oil. The results focused on the frictional torque, wear scar diameter, friction coefficient and the flash temperature. Following the completion of the wear test experiments, the ball wear condition and lubricant properties were observed. These results show that RBD palm olein has a lower coefficient of friction than paraffinic mineral oil; however showed a high oxidation effect under high temperature work conditions.

Study of Henna (Lawsonia inermis) as Natural Corrosion Inhibitor for Aluminum Alloy in Seawater

Commercial henna (Lawsonia inermis) was investigated to inhibit the corrosion of aluminum alloy through immersion in seawater. The aluminum alloy (5083) was prepared in size of 25mm × 25mm × 3mm. The immersion test was conducted in seawater with different concentration of henna, 100ppm, 300ppm, 500ppm for duration of 60 days. Four characterizations were performed in this study which was weight loss study, Fourier Transform Infrared (FTIR), Electrochemical Impedance Spectroscopy (EIS) and adsorption isotherm. The results indicated that henna has major constituents of lawsone which contributed to the chemisorptions or adsorption process by forming an isolation layers on the aluminum alloy surface which follows the Langmuir adsorption isotherm. It was found that the protection layer attached on metal was not permanent and precipitation occurred as the time increases. The highest inhibition efficiency was found at 88% (500ppm). This research found that henna is an excellent natural inhibitor for aluminum alloy in seawater.

Efficiency Comparison of some Natural Products on Corrosion Inhibition of Al-Mg-Si Alloy

The comparison of the efficiency of some natural products (natural honey, vanillin and tapioca starch) on corrosion inhibition of Al-Mg-Si alloy is investigated in seawater solution at room temperature, using potentiodynamic polarization (PP), linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) measurements. The evolution of the corrosion potential (Ecorr) and corrosion current density (icorr) obtained from Tafel extrapolation of polarization curves, and the polarization resistance (Rp) values determined from LPR and EIS measurements indicate that the corrosion rates of Al-Mg-Si alloy decrease with the increasing the natural products concentration. In all cases, the increasing order of inhibition efficiency is: Natural honey < Vanillin < Tapioca starch.

The Effect of Concentration of Lawsonia inermis as a Corrosion Inhibitor for Aluminum Alloy in Seawater

Lawsonia inermis also known as henna was studied as a corrosion inhibitor for aluminum alloy in seawater. The inhibitor has been characterized by optical study via Fourier transform infrared spectroscopy (FTIR). The FTIR proves the existence of hydroxyl and carbonyl functional groups in Lawsonia inermis. Aluminum alloy 5083 immersed in seawater in the absence and presence of Lawsonia inermis was tested using electrochemistry method, namely, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP). EIS and PP measurements suggest that the addition of Lawsonia inermis has caused the adsorption of inhibitor on the aluminum surface. The adsorption behavior of the inhibitor follow Langmuir adsorption model where the value of free energy of adsorption, , is less than 40 kJ/mol indicates that it is a physical adsorption. Finally, it was inferred that Lawsonia inermis has a real potential to act as a corrosion inhibitor for aluminum alloy in seawater.

Review on potential for waste recycled based bioenergy for marine system

Human status today can best be defined as an age of knowledge, efficiency and sustainable developments towards fulfilling significant part of human existence in this beautiful planet we all share. Previous time in human history has been dominated with various experimentation, knowledge acquisition which has resulted to new discovery and new philosophy of doing things in efficient, sensitive, cooperative and above all sustainable manner (maintaining quarto bottom balance, i.e. economic, technical, environmental and social, between man technosphere and environsphere world in order to sustain continuous healthy existence of our planet and the right of future generation). New knowledge and technology have emerged, since there is no drain in this planet, the greatest challenge for humanity lies in recycling our waste to the lowest level of usage. This paper will discuss the need to choose waste derived biofuel above all other food sources. This paper also discusses risk and abatement required for choice of best practice sustainable bioenergy generation for marine system.

Laboratory tests on heat treatment of ballast water using engine waste heat

ABSTRACT Waste heat recovery from shipboard machineries could be a potential source for heat treatment of ballast water. Similar to a shipboard schematic arrangement, a laboratory-scale engine-heat exchanger set-up harvesting waste heat from jacket water and exhaust gases was erected to test the level of species’ mortalities. Mortalities were also assessed under experimental conditions for cultured and natural plankton communities at laboratory level. Effect of pump impellers on species’ mortalities were also tested. Exposures between 60°C and 70°C for 60 sec resulted in 80–100% mortalities. Mortalities due to pump impeller effects were observed in the range of 70–100% for zooplankton. On the laboratory-scale arrangement, >95% mortalities of phytoplankton, zooplankton and bacteria were recorded. It was demonstrated that the temperature of tropical sea waters used as secondary coolant can be raised to cause species’ mortalities, employing engine exhaust gases. The results also indicated that pump impeller effects will enhance species’ mortalities. The limitations of the shipboard application of this method would be the large ballast volumes, flow rates and time for treatment. GRAPHICAL ABSTRACT

Controlled Release of Lysozyme from Double-Walled Poly(Lactide-Co-Glycolide) (PLGA) Microspheres

Double-walled microspheres based on poly(lactide-co-glycolide) (PLGA) are potential delivery systems for reducing a very high initial burst release of encapsulated protein and peptide drugs. In this study, double-walled microspheres made of glucose core, hydroxyl-terminated poly(lactide-co-glycolide) (Glu-PLGA), and carboxyl-terminated PLGA were fabricated using a modified water-in-oil-in-oil-in-water (w1/o/o/w2) emulsion solvent evaporation technique for the controlled release of a model protein, lysozyme. Microspheres size, morphology, encapsulation efficiency, lysozyme in vitro release profiles, bioactivity, and structural integrity, were evaluated. Scanning electron microscopy (SEM) images revealed that double-walled microspheres comprising of Glu-PLGA and PLGA with a mass ratio of 1:1 have a spherical shape and smooth surfaces. A statistically significant increase in the encapsulation efficiency (82.52 ± 3.28%) was achieved when 1% (w/v) polyvinyl alcohol (PVA) and 2.5% (w/v) trehalose were incorporated in the internal and external aqueous phase, respectively, during emulsification. Double-walled microspheres prepared together with excipients (PVA and trehalose) showed a better control release of lysozyme. The released lysozyme was fully bioactive, and its structural integrity was slightly affected during microspheres fabrication and in vitro release studies. Therefore, double-walled microspheres made of Glu-PLGA and PLGA together with excipients (PVA and trehalose) provide a controlled and sustained release for lysozyme.

The Effect of Sliding Speed on Friction and Wear of RBD Palm Olein

In this paper, the effect of sliding speed on the anti-friction of RBD palm olein was investigated using four-ball tribotester. The speeds were varied from 800 to 1400 rpm. The normal load was set to 40 kg and the test oil was heated up to 75 °C before the experiments. The result showed that palm olein has low friction coefficient compared to additive-free paraffinic mineral oil.

Potential of waste based biomass cogeneration for Malaysia energy sector.

Reuse of waste as source energy remains sustainable energy source for humanity. The processing of waste provide fuels for electricity, heat generation, and transportation fuels environmental advantages in term of energy production that lead to vast reduction in the waste stream, production of valuable byproducts, wasteland reduction and the killing of the pathogens and bacteria that cause disease as well as provision of reliability for food safety and mitigation go Green House Gas release.. The process calorific content of biomass is considered less than fossil fuel, but can be more sustainable by using hybrid cogeneration biomass system for marine system. Recent global political will has provided spill in Malaysia policy to pursue production of renewable energy of modest percentage increase of 20 percent by 2020. This paper present the status of biomass, constrain and the way forward in Malaysia.

Effects of Low Proportion Palm Fatty Acids Methyl Ester Blends on the Performance and Combustion of Marine Diesel Engine

Shipping activities are major contributors to air pollution at sea which mostly occur as a result of ships exhaust emissions. Stringent emission limits imposed by the International Maritime Organization (IMO) and concerns about the depletion of fossil fuel reserves have hastened the need to find new alternative fuels for marine engines. This study investigates the effects of a low proportion of palm fatty acid methyl ester (PFAME) biodiesel which is renewable and environmentally friendly fuel on marine diesel engines performance and combustion characteristics. The results revealed the use of PFAME biodiesel blends reduces the harmful gases emission CO2 and NOX emission up to 9.1% and 7.8%, respectively. Oxygen elements in biodiesel has contributed to increase peak in-cylinder pressure and heat release rate up to 2.7% and 4.5% respectively, thereby promoting complete combustion. Besides that, the brake specific fuel consumption raised by 18.8% at higher engine speeds. This finding suggests that a low concentration of PFAME biodiesel is suitable for use in marine diesel engines without engine modification, thereby providing a positive benefit to the environment in terms of lower emission of toxic gases.