Judul: Kajian teknik elektrokoagulasi untuk pemisahan mikroalga
Abstrak: Although microalgae can grow fast in liquid wastes, there was no efficient technique yet for remove them. An electro-coagulation technique was examined to remove microalgae from the liquid wastes. For the batch system electro-coagulation process used in this experiments two aluminum electrode. This type of metal selected because it could introduce the coagulation agent into the liquid, there by microalgae could be removed. The used wastes are wastewater from animal husbandry and synthetic wastewater. The experiment was done by batch method used 1 Liter microalgae for each treatment on direct current variated from 9, 12 and 15 Volt and operation time from 10 to 40 minutes. The result of treatment were remarkably good and the efficiencies to total suspended solid (TSS) as the amount of microalgae removed reached to 51,55% for husbandry wastewater and 28,98% for synthetic on the direct current of 15 Volt and operation time 40 minutes. Beside can removed microalgae from wastewater electro-coagulation give effect for the other parameters of the wastewater like turbidity, color, concentration of COD, concentration of phosphate and pH value. The reduction of those parameters value reached along with the raising direct current voltage and operating time.
Keyword: 

Judul: Kajian Proses Koagulasi Sebagai Perlakuan Pendahuluan Pada Teknik Pemisahan Mikroalga dengan Sedimentasi
Abstrak: Microalgae can grow fast in wastewater. Several techniques have been developed to remove it, but do not provide optimal results. Chemical and electro-coagulation as a pre-treatment of sedimentation technique was examined to remove microalgae from the wastewater. The wastewater used were effluent from animal farm and slaughterhouse. Chemical coagulant used are Poly Aluminium Chloride (PAC) and ferrous sulfate, whereas for electrocoagulation iron electrode was used. The efficiency of Total Suspended Solid (TSS) removal as a measure of microalgae removal reached to 98% for slaughterhouse wastewater at pH 7 with a PAC dose of 100 mg/L, 98% for animal farm wastewater at pH 7.25 with a PAC dose of 200 mg/L, 99% for slaughterhouse wastewater at pH 6.5 with a ferrous sulfate dose of 65 mg/L and 80% for animal farm wastewater at pH 6.75 with a ferrous sulfate dose of 120 mg/L. The efficiency of TSS removal as a measure of microalgae removal reached to 79% and 49% for slaughterhouse and animal farm wastewater on the direct current of 15 volt and operation time 40 minutes. In addition to microalgae removal, chemical and electrocoagulation lead to reduction of the wastewater turbidity, color, Chemical Oxygen Demand (COD) and phosphate.
Keyword: 

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