Muhammad Zakir

Cerenkov and liquid scintillation analysis of the triple label 86Rb35S33P

Abstract A method was developed for the analysis of 86Rb35S33P as a triple-label. The analysis of the total activity of composite mixtures of the three radionuclides was demonstrated to be quantitative by the liquid scintillation efficiency tracing technique with recoveries between 99.7–100.4%. The activity of 86Rb in the triple label was determined by Cerenkov counting in water with a 52% counting efficiency. The combined activities of 35 S + 33 P were determined by subtracting the activity of 86Rb from the total activity of the triple label. The separate activities of 35S and 33P are obtained by difference after a period of time sufficient for the decay of 33P to negligible levels leaving only residual 35S in the sample. The method described is useful for the analysis of 86Rb35S33P as a triple label for the elements KSP in studies of fertilize use efficiency.

Production of Biodiesel from Lipid of Phytoplankton Chaetoceros calcitrans through Ultrasonic Method

A research on production of biodiesel from lipid of phytoplankton Chaetoceros calcitrans through ultrasonic method has been done. In this research, we carried out a series of phytoplankton cultures to determine the optimum time of growth and biodiesel synthesis process from phytoplankton lipids. Process of biodiesel synthesis consists of two steps, that is, isolation of phytoplankton lipids and biodiesel synthesis from those lipids. Oil isolation process was carried out by ultrasonic extraction method using ethanol 96%, while biodiesel synthesis was carried out by transesterification reaction using methanol and KOH catalyst under sonication. Weight of biodiesel yield per biomass Chaetoceros calcitrans is 35.35%. Characterization of biodiesel was well carried out in terms of physical properties which are density and viscosity and chemical properties which are FFA content, saponification value, and iodine value. These values meet the American Society for Testing and Materials (ASTM D6751) standard levels, except for the viscosity value which was 1.14 g·cm−3.

Pulse height spectral analysis of 3H:14C ratios

Abstract Activity ratios of 3 H: 14 C of isotope-labeled substances are employed commonly in biochemical studies of reaction mechanisms and pathways. The liquid scintillation pulse height spectral index (SIS) of a composite sample of 3 H and 14 C was demonstrated to provide an index to the 3 H: 14 C activity ratio of the sample. Linear and logarithmic relations between the 3 H: 14 C activity ratio and SIS were defined for a given level of quench. When the level of quench is maintained constant, the SIS was demonstrated to be directly correlated to the 3 H: 14 C activity ratios of the sample. A mean recovery of 102.3% was obtained for calculated 3 H: 14 C activity ratios over the range of 0.097:1–9.698:1. The method described provides the 3 H: 14 C activity ratios of samples without the need for determining the separate activities of the individual radionuclides of the dual label.

Production of Biodiesel from Lipid of Porphyridium cruentum through Ultrasonic Method

A research on production of biodiesel from lipid of phytoplankton Porphyridium cruentum through ultrasonic method has been done. In this research, we carried out a series of phytoplankton cultures to determine the optimum time of growth and biodiesel synthesis process from phytoplankton lipids. Process of biodiesel synthesis consists of two steps, that is, isolation of phytoplankton lipids and biodiesel synthesis from those lipids. Oil isolation process was carried out by ultrasonic extraction method using ethanol 96%, while biodiesel synthesis was carried out by transesterification reaction using methanol and KOH catalyst under sonication. Weight of biodiesel yield per biomass Porphyridium cruentum is 40,27%. Characterization of biodiesel was well carried out in terms of physical properties which are density and viscosity and chemical properties which are FFA content, saponification value, and iodine value. These values meet the American Society for Testing and Materials (ASTM D6751) standard levels, except for the density value which was 0.9461 g·cm−3 and the FFA content which was 4.6671%.