Apart from being the primary source of food to other living things, plants also have medicinal value to treat various kinds of diseases. In recent years, it has been proposed that the extract from plants may be used as natural antioxidants which can help to prevent the generation of carcinogens in human body. In addition, plants also have antimicrobial agents to inhibit the growth of pathogenic microbes. This study was intended to investigate the antioxidant properties and antimicrobial activity of methanolic extract of Tinospora crispa stems extracted using soxhlet extraction method. The antimicrobial properties of T. crispa stems extract were tested using disc diffusion method against Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 11778, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Candida albicans IMR C S23/11 A and Saccharomyces cerevisiae IMR S 617/068. The antioxidant properties of the extract were investigated by using Total Phenolics Content (TPC), Total Flavonoids Content (TFC), DPPH free radical scavenging and b–carotene bleaching assays.  The TPC value was 6.12 g GAE/100 g of dried extract while the TFC value was 55.58 g QE/100 g of dried extract. The IC50 of DPPH scavenging assay for the extract and ascorbic acid were 0.21 and 0.04 mg/mL, respectively. The average percentage of b–carotene bleaching assay was 38.3 % as compared to BHT, which was 45.1%.  The disc diffusion method showed no inhibition zone against all the strains of microorganisms at all concentrations of the extracts (0.5, 1.0, 2.5 and 5.0 mg/disc).

This paper presents the optimal approach to mitigate scintillation effects caused by ionosphere irregularities, principally plasma bubbles that occur mostly in ionosphere in low latitude. The mitigation is made by figuring out the scintillation index for the chosen geographic location, extracted from the received real-time RINEX data. Various simulators and programs are used, mainly MATLAB, such as Transionospheric Simulator, Scintillation Index Simulation Program, Power Spectral Density Program, Read RINEX Observation Program and Bubble Scintillation Simulation Program. Based on the detrend signal, MATLAB function that is polyfit will be used to find the phase and amplitude spectra. Comparison simulations result with Bubble ScintillationSimulation Program, which is programmed to detect plasma bubbles in certain geographical area under observations, is executed. The result of this study will provide information for ionospheric activity and also enable GPS system to make predictions and necessary adjustments to maximize its navigations.