Jurnal ILMU DASAR
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Functionalization of Polyethylene Films With pH-Responsive Acrylic Acid Using Grafting Technique Induced by UV-Ray
Full text linkThis research was carried out to study photografting of acrylic acid onto linear low-density polyethylene (LLDPE) film, induced by UV ray at 60°C, as a function of monomer concentration and irradiation time. This research was conducted since it has been known that hydrogels formed by polyacrylic acid exhibit shrinking and swelling behaviors according to the change in pH of the aqueous medium. Therefore, the acrylic acid-grafted LLDPE film is expected to exhibit a pH-responsive function, in which it swells in alkaline media (pH = 8) and shrinks in acidic media (pH = 4). Xanthone was used as a photoinitiator, which was coated on the film earlier. The samples were characterized using attenuated total reflection infrared spectroscopy and a scanning electron microscope analysis. The pH-responsive experiments revealed that the samples exhibited the pH-responsive characters, as expected, in which they shrank and swelled in acidic and alkaline media, respectively. The pHresponsive character was higher for the samples prepared in the system containing monomer at higher concentration. The different extents of the pH-responsive character of the resulting grafted PE films were discussed in terms of location of grafted chains in the film substrate
Estimating of Survival Function of Hepatitis Virus in Jember
Full text linkStatistical method to analyse data of lifetime is called survival analysis. One problem in survival analysis is estimation of survival function. This function can be estimated by using nonparametric method. One problem in medical is to study the lifetime of hepatitis virus. In this paper the lifetime of hepatitis viruses (A, B, C) are estimated using Nelson’s method. The results show that the three type of viruses have different lifetime and virus type A has the longest lifetime
Growth of Bacteria Isolat Consortium From Benakat on High Salainity Crude Oil Media
Full text linkThe production and cunsumption of oil and petroleum product are increasing worldwide and threat of oil pollution is increasing accordingly. About 10 million tons of oil and petroleum products are used worldwide each day, it will occur 5% of all oil pollution entering the sea. For that reason, needs a treatment to handle and remediate aquatic ecosystem like former. Bioremediation is a process to detocsify dan degrade crude oil. Expected from this process, land and aquatic environment where were polluted by petroleum can be natural. Treatments are divided into three stages, which are (1) isolation of dominant microorganism that degraded petroleum hydrocarbon in 15% salinity and TPH 10%, (2) Identification of bacteria with biochemistry tes and Analytical Profile Index 20 NE test (3)Biodegradation ability test in 15%, 10% salinity and 30‰ (seawater salinity) and TPH (Total Petroleum Hidrocarbon) 1%, 2.5 %, 5 %, and 10 %. The microorganisms that were identified from the isolation crude oil from Benakat are Pseudomonas aeruginosa, Aeromonas hydrophila and Agrobacterium radiobacter. Total sel microorganisms/ml in exponential phase are P. aeruginosa: 2.42E/ml, A. hydrophila: 2.99E+14 /ml, A. radiobacter: 2.42E+14/ml, and mixed culture microorganism: 4.65E/ml. The average percentage sequence degradation from the optimum growth are mixed culture = 92%, P. Aeruginosa = 90%, A. hydrophila = 88%, and A. radiobacter = 79%. The percentage sequence degradation of mixed culture in 15% salinity and 1%, 2,5%, 5%, 10% TPH concentration are 90%, 84%, 97%, 94%. Otherwise, 30‰ salinity and 1%, 5%, 10% TPH concentration, the percentage of biodegradation are 98%, 96%, 84%
Onyx and Marmer Objects Modeling by Joining and Choosing Parametric 2) 1) Modifications of Bezier Revolution Surfaces
Full text linkWe formulate application of Bezier revolution surfaces for modeling onyx and marmer objects in three steps as the following. Firstly, calculating the parametric representation of Bezier revolution surfaces and its shape modification in some different forms is done. Secondly, we formulate parametric continuity for joining the surfaces. Finally, the application of those formulas for modeling onyx and marmer objects of revolution by using computer are simulated
Chromatogram and Spectram Profiles Antimalarial Isolate from Dichloromethane Extract of Artocarpus champeden Spreng. Stem Bark
Full text linkThe isolate which possessed antimalarial activity had been isolated from dichloromethane extract of Artocarpus champeden Spreng. Stem bark. The isolate inhibited Plasmodium falciparum growth in vitro by IC 0.024±0.011 μg/ml. Chromatogram and spectram of isolate analysis showed that it contained flavonol as a major compound
Antioxidant Activity of Polar Fraction of Methanol Extract from Tree Bark Of Shorea acuminatissima with DPPH Method
Full text linkShorea accuminatissima, which is known locally as Meranti kuning, is one species of Dipterocarpaceae family. This plant contains compounds that are expected to have antioxidant activity. This research was carried out to examine the radical scavenger activity of polar fraction of methanolic extract from the tree bark of S. accuminatissima by using DPPH (2,2-difenil- 1-pikrilhidrazil) method with vitamin C as comparator. Powder of tree bark of S. accuminatissima was macerated in methanol. The methanolic extract was then evaporated to obtained dry extract. Extract with concentration of 200, 100, 50, 25 and 10 µg/mL were used to test its radical scavenger activity. The result showed that polar fraction of methanolic extract and vitamin has IC value of 319.83 and 3.72 µg/mL, respectively