Judul: Katalis Elektrohidrodeklorinasi Tetrakloroetilena Berbasis Barium Heksaferit Terdoping Nikel
Abstrak: Tetrakloroetilena (PCE) adalah salah satu senyawa organoklorin yang dinyatakan sangat berbahaya oleh US EPA (United States Environmental Protection Agency). Penggunaan metode elektrohidrodeklorinasi dengan katode Ba1-xFe12NixO19 dapat menggurangi bahaya tersebut. Ba1-xFe12NixO19 dengan komposisi x = 0.0, x = 0.3, dan x = 0.4 disintesis dengan metode ko-presipitasi menghasilkan serbuk berwarna merah-kecokelatan dan mempunyai sifat magnet. Pencirian dengan Spektroskopi Inframerah Transformasi Fourier (FTIR) menunjukkan spectrum Ba1-xFe12NixO19 dengan gugus Ba-O, Ni-O dan Fe-O pada bilangan gelombang masing-masing 547.78 cm-1, 437.84 cm-1 dan 582.50 cm-1. Informasi yang diperoleh dengan Difraksi Sinar-X (XRD) menunjukkan rumus molekul senyawa Ba1-xFe12NixO19 adalah BaFe12O19 yang didoping dengan NiO pada permukaan. Elektrode dibuat dengan mencampurkan Ba1-xFe12NixO19 dan lem karbon. Nilai konduktivitas elektrode tertinggi didapat dengan nisbah Ba1-xFe12NixO19 dan lem karbon yaitu 1:4. Berdasarkan hasil elektrohidrodeklorinasi PCE dengan elektrode Ba1-xFe12NixO19 dan tegangan (10 V, 14 V) selama 30 menit diketahui bahwa kadar PCE yang terdegradasi, yaitu 51% sampai 100%.
Keyword: magnet, barium heksaferit terdoping nikel, katode, tetrakloroetilena

Judul: Komposit Polianilina/Barium Heksaferit Terdoping Tembaga sebagai Elektrokatalis dalam Medium Alkali
Abstrak: Elektrokatalis berguna dalam mempercepat reaksi reduksi oksidasi melalui transfer elektron langsung. Tujuan penelitian ini adalah memperoleh bahan yang baik sebagai elektrokatalis dalam medium alkali dan menganalisis aktivitas katalitiknya secara elektrokimia. BHF-Cux dengan x = 0, 0.4 dan 4 mol disintesis secara kopresipitasi menggunakan zat pengendap NaOH 1.5 M pada suhu 0-5 °C kemudian dikalsinasi selama 4 jam pada suhu 750 °C. BHF-Cux dikompositkan dengan polianilina secara polimerisasi in situ. Analisis gugus fungsi dengan FTIR dan analisis fase dengan XRD menunjukkan bahwa komposit polianilina/barium heksaferit terdoping tembaga telah berhasil disintesis. Analisis sifat elektrokimia menggunakan potensiostat dengan teknik linear sweep voltammetry menunjukkan aktivitas katalitik. Nilai I0 yang besar dan kemiringan tafel yang kecil menunjukkan sifat katalitik yang baik. Komposit polianilina/barium heksaferit merupakan elektrokatalis yang baik dengan nilai I0 sebesar 0.06 mA, J0 sebesar 0.0182 mA/cm2 , dan kemiringan tafel 141.74 mV/dec.
Keyword: Barium hexaferrite, Electrocatalyst, Polyaniline, Sintesis BHF, Elektrokimia, Penggunaan XRD, Penggunaan FTIR

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