Judul: Pengaruh metode netralisasi dan kecepatan pengadukan terhadap mutu faktis gelap dari minyak jarak (Castor oil)
Abstrak: Faktis merupakan material padat, agak elastis yang terbuat dari minyak nabati melalui vulkanisasi dengan sulfur atau sulfur klorida. Aplikasi faktis cukup luas karena meliputi penggunaan dalam pengolahan karet alam maupun sintetis. Faktis gelap diperoleh melalui reaksi antara minyak dengan sulfur pada suhu tinggi dan umumnya digunakan untuk barang jadi karet yang berwarna gelap, seperti selang air, kawat, kabel, peralatan rumah tangga, penghapus, spons, gasket untuk lemari pendingin dan automotif, dan lain-lain. Tujuan dari penelitian ini adalah: 1) Mengetahui pengaruh metode netralisasi dan kecepatan pengadukan terhadap mutu faktis gelap; 2) Mendapatkan kombinasi perlakuan terbaik untuk menghasilkan faktis gelap dengan menggunakan bahan baku minyak jarak (castor oil).
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Judul: Pengaruh Suhu dan Konsentrasi Sulfur Terhadap Mutu Faktis Gelap Berbahan Baku Minyak Jarak (Castor Oil)
Abstrak: Dark factice is one of the rubber processing aids obtained by vulcanization/reaction of fatty oil with sulphur at high temperature. Factice serve as mixing materials in the rubber industry and are used for various purposes such as in the manufacture of rubber, cable coatings, cellular rubber goods, rubber goods from latex, and in the manufacture of rubber goods using the calendar tool, extruder, and injection molding equipment. Factice wide application because the processing involves the use of natural or synthetic rubber. The purpose of this research are: 1.) Knowing the influence of temperature and sulfur concentration toward dark factice quality; 2.) Obtain the best treatment combination to produce a dark factice using raw material of castor oil. Factice manufacture begins with the neutralization of oil, by adding 1 ppho (parts per hundred weight of oil) Na2CO3 to the oil while stirring (145 rpm) and heated until a temperature treatment has achieved. After the treatment temperature has reached, respectively 5 ppho ZnO and sulfur (the amount in accordance with the treatment) is inserted into the oil while continuing the stirring. The reaction is continued until dark factice is formed, that is the mixture returned into a solid. The Design experiment in this research was completely randomized factorial design with two treatments, that are temperatures on the level of 140, 150, 160 and 170oC and sulfur concentrations on the level of 25, 30 and 35 ppho. Castor oil which is used has an average value of iodine number of 86.15 (g iod/100 g oil) and the average value of acid number of 1.02 (mg KOH/ g oil). Based on the analysis of variance, treatment of temperatures have real impact on dark factice’s acetone extract content and free sulfur content, and the treatment of sulfur concentrations gave a significant effect on dark factice’s free sulfur content and ash content. Dark factice which has the best chemical parameter based on acetone extract content, resulting in treatment of 170oC temperature and sulfur concentration of 35 ppho, but is still classified as third quality (> 35%) with average value of 86.12% acetone extracts. Dark factice has been obtained with treatment of 170oC temperature and sulphur concentration of 25 ppho has the lowest free sulphur content with average value of 1,24% free sulphur contents. The pH value of dark factices have average of 10 and the average of ash content about 5%.
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Judul: Studies on growth spurt and aging in higher primates
Abstrak: single measurement that best defines the health and nutritional status of children, just as it provides an indirect measurement of the quality of life of an entire population. The pattern of human growth reflects the biocultural evolution of our species. The human pattern of growth and development (ontogeny) appears to differ markedly from patterns of ontogeny in other primate species. Three studies are reported here which deal to the growth and development of human and chimpanzee (Pan troglodytes). These three studies allow us to contrast the phenomena of adolescence growth spurt and female elderly bone loss in chimpanzee and human as chimpanzee is the closest species to humans within extant nonhuman primates. In the first, a cross-sectional study of growth of the body size and somatotype of 363 Javanese girls and 299 Javanese boys aged 4 to 20 years from Magelang Regency, Indonesia was described. In the second, cross-sectional and longitudinal studies in the growth of chimpanzee second metacarpal bone linear dimensions from individuals aged 0 to 43.6 years were used for comparison. While in the third, cross-sectional and longitudinal studies in the growth of chimpanzee body size (body mass and anterior trunk length) and second metacarpal bone mineral content were derived. In measuring the second metacarpal dimensions and mineral content, a total of 568 radiographs of chimpanzee's proximodistal left hands were used. They were taken from 68 females and 49 males aged 0 to 43.62 years old. We applied an image analysis system, Scion Image Release Alpha 4.0.3.2 software for Windows to measure bone linear dimensions and bone mineral content. Humans present complex and sinuous growth curves for both body weight and height. A clear growth spurt could be demonstrated by cross-sectional analysis in our girl subjects at around aged 11.5 years and in our boy subjects at around aged 12.5 years. In longitudinal series, not in cross-sectional, several representative chimpanzees of both sexes showed a pre-adult growth spurt on the body sizes, bone dimensions and bone mineral content. They ranged at age 4.5 to 8.5 years. This underscore the fact that adolescent growth spurt in linear dimension was not a universal feature of anthropoid primate ontogeny. Bone loss is a well established characteristic of human female aging. Based on crosssectional analyses the sequential decline of bone mass in female chimpanzee may be said to be genuine. On the other hand, we found in adulthood through elderly, male chimpanzees show a longer plateau than female chimpanzee, that is, bone mineral content is maintained in male.
Keyword: Javanese children, growth spurt, chimpanzee, second metacarpal bone, bone loss, Higher Primates