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Working fluid of R134a is widely used as a refrigerant in automotive air conditioner. This refrigerant has a good performance on the automotive air conditioner. However, because R134a still has a high global warming potential, this refrigerant must be reduced and replaced by environmentally friendly refrigerants. Hydrocarbons of R600a, R290 and their mixtures are widely used as substitute refrigerant. These refrigerants are natural fluids, no effect on the climate, inexpensive and readily available. There are three performances will be discussed in the present study, namely COP, mass flow rate and compression ratio. The present study investigates the effect of three refrigerants, i.e. R134a, R600a and R290 on the performance of automotive air conditioner. The results show that the COP of R600a is higher than those R134a and R290. For the same cooling capacity, the mass flow rate of R600a is approximately 50% of R134a for all ambient temperatures. In addition, the compression ratio of R600a is lower than that of R134a.

Cellulosic material derived from Merbau (Intsia bijuga) was extracted at atmospheric pressure. In the initial stage the sample was delignified using peroxyacetic acid to remove the amorphous. In the second stage the samples were double bleached using hydrogen peroxide (H2O2) and sodium Hydroxide (NaOH). From the X-Ray Diffraction (XRD) data it is evident that both acid and alkali bleached celluloses have rich cellulose I structure. The results are supported by FTIR study in which all samples shown typical spectra of cellulose.

Aluminium (Al) thin films on polyimide (PI) plastic substrates prepared via thermal evaporation technique and annealed in nitrogen (N2) ambient at different temperatures (250 - 400°C, for 30 minutes) have been investigated. Structural properties of the as-evaporated film have been studied by high resolution X-ray diffraction (HR-XRD). The result illustrates crystalline nature of the Al thin film with a dominant Al (111) peak at 2θ = 38.4°. Atomic force microscope (AFM) shows increased surface roughness root mean square (RMS) with increased annealing temperature (with roughness of 11.96 nm at 400°C). Sheet resistance drops with increased temperature and records the lowest reading (64 mΩ/) at 400°C. Besides, increased annealing temperature also results in reduced surface reflectance (with minimum reflectance of 73% reflectance in the visible region at 400°C). The effects of the resulting Al back contact properties towards thin film silicon (Si) solar cells on PI substrates were subsequently discussed.

Zinc oxide (ZnO) nanoparticles with spherical morphologies were successfully produced via precipitation of Zn and I2 with DEA was employed as a chelating agent. The products were further heat treated at four different calcinations temperature commences from 250 ⁰C to 1150 ⁰C. Studies on ZnO structural, morphologies and optical characteristic with respect to calcinations temperatures were conducted using XRD, TEM and PL spectroscopy respectively. The XRD spectra reveal hexagonal wurtzite signature along with preferred orientation growth in (101) plane. Particles size of ~ 60 nm and strong blue-violet emission peak of 417 nm (3.0 eV) has been observed for ZnO calcined at 850 ᵒC. Results reveal a close relationship between the calcinations temperature and ZnO microstructure whereas, its luminescence behaviour showing a strong depending on ZnO microstructure.

This study describes the formation of spherical gold nanoparticles (AuNPs) using a simple seeded-growth technique. The size and surface morphology of AuNPs were investigated using transmission electron microscopy (TEM) and UV-Vis spectrophotometer was used to determine the wavelength and absorption of AuNPs. In the seed stage, the effect of trisodium citrate volume was studied. The size of AuNPs at seed stage was varied from 15 to 40 nm with decreasing volume of trisodium citrate. In the growth stage, the effects of seed solution volume and concentration of hydroxylamine were studied. The size of AuNPs produced became larger when the amount of seed solution was reduced. This approach was beneficial to produce AuNPs with the size range from 15 to 150 nm. The increase of hydroxylamine concentration increased the size of AuNPs. However, after the concentration of hydroxylamine reached supersaturation condition (3 M NH2OH.HCl), the AuNPs formed in a bulk and clusters. Selected sizes of AuNPs were then conjugated to antibody and proved by testing on the immunoassay test strip. The observation using naked eyes for the appearance of red lines on the immunoassay test strip showed that AuNPs were successfully conjugated to antibody and specifically bound to the antigen drawn on the strip assay by tested with positive and negative serum of the disease.