Judul: Hidrogenasi CO2 Menjadi Asam Format di Atas Permukaan Katalis Grafena Terdoping N dan Cu
Abstrak: Peningkatan emisi global CO2 telah memberikan pengaruh yang signifikan terhadap kondisi lingkungan. Salah satu upaya yang dilakukan untuk mengurangi emisi CO2 adalah mereduksi CO2 melalui reaksi hidrogenasi menjadi asam format di atas permukaan N3Cu-G. Penelitian ini berfokus pada studi Density Fuctional Theory (DFT) untuk menjelaskan peranan permukaan N3Cu-G dalam mengadsopsi molekul adsorbat serta melemahkan ikatannya yang mampu mendorong terjadinya reaksi hidrogenasi CO2 menjadi asam format. Hasil dari perhitungan menunjukkan bahwa molekul CO2 adalah molekul yang stabil selama proses adsorpsi. Pada sistem piridinik, hidrogenasi CO2 pertama untuk pembentukan intermediat format lebih disukai daripada pembentukan karboksil dengan energi aktivasi sebesar 0,89 eV. Hidrogenasi lebih lanjut dari bentuk format menjadi asam format memiliki energi aktivasi sebesar 0,12 eV dimana asam format terikat kuat di atas permukaan. Pada sistem grafitik, hidrogenasi CO2 untuk pembentukan senyawa intermediat format lebih disukai daripada pembentukan karboksil dengan energi aktivasi bernilai nol. Hidrogenasi lebih lanjut dari bentuk format menjadi asam format juga memiliki energi aktivasi bernilai nol. Baik hidrogenasi CO2 untuk pembentukan format dan asam format pada masing-masing sistem merupakan reaksi eksotermik.
Keyword: asam format, DFT, energi aktivasi, hidrogenasi CO2, N3Cu-G

Judul: Studi Komputasi pada Carbon Dots Terfungsionalisasi Gugus Amina untuk Pengindraan Hidrogen Peroksida
Abstrak: Dalam penelitian ini, penginderaan hidrogen peroksida (H2O2) diselidiki pada carbon dots yang terfungsionalisasi gugus amina (NH2-Cdots) pada tiga posisi -NH2 yang berbeda, dan atom N berperan sebagai situs aktif menggunakan pendekatan komputasi kuantum. B3LYP dan 6-31G (d,p) sebagai metode fungsional dan basis set yang digunakan dalam teori fungsional kerapatan (TFK) untuk perhitungan keadaan dasar. Sedangkan, CAM-B3LYP dan basis set yang sama digunakan dalam teori fungsional kerapatan-dependen waktu (TFK-DW) untuk perhitungan keadaan tereksitasi. Struktur teroptimasi menunjukkan bahwa H2O2 diadsorpsi secara kimia pada 1-sim lebih baik dibandingkan dengan 2-sim dan 3-sim melalui interaksi ikatan hidrogen C–N⋯H dengan energi adsorpsi -10,61 kcal/mol. Distribusi muatan atom Mulliken dan potensial elektrostatik keduanya digunakan untuk menentukan reaktivitas molekul pada tingkat atom. Orbital molekul Frontier digunakan untuk memahami mekanisme transfer elektron. Selain itu, energi interaksi ikatan hydrogen dan juga klasifikasi tipe interaksinya pada 1-com adalah -6,8067 kcal/mol dan dikategorikan sebagai interaksi ikatan hidrogen. Pada Analisa TFK-DW, spektrum absorpsi UV-Vis dan panjang transfer muatan untuk memahami mekanisme penginderaan H2O2 dalam keadaan tereksitasi pada semua struktur adalah hipokromik dan photo-induced charge difference. Semua analisis menunjukkan 1-sim lebih menguntungkan berinteraksi dengan H2O2 daripada 2-sim dan 3-sim; dan, diyakini bahwa NH2-Cdots mungkin menjadi kandidat potensial untuk merasakan keberadaan H2O2 pada aplikasi kemosensor., In this study, hydrogen peroxide (H2O2) sensing investigated on amine groupfunctionalized carbon dots (NH2-Cdots) at three different -NH2 positions, and the N atom is role-playing as an active site using a quantum computational approach. B3LYP and 6-31G (d,p) as functional methods and basis sets used in density functional theory (DFT) for ground state calculations. Meanwhile, CAM-B3LYP and the same base set were used in the time-dependent density functional theory (TD-DFT) for excited state calculations. The optimized structure showed that H2O2 was chemically adsorbed on 1-sim better than 2-sim and 3-sim through the interaction of C–N⋯H hydrogen bonds with adsorption energy of -10.61 kcal/mol. Mulliken atomic charge distribution and electrostatic potential are both used to determine reactivity molecules at the atomic level. Frontier molecular orbitals are used to understand electron transfer mechanisms. In addition, the hydrogen bond interaction energy and also the classification of the interaction type at 1-com is - 6.8067 kcal/mol and is categorized as a hydrogen bond interaction. In TD-DFT analysis, UV-Vis absorption spectrum and charge transfer length to understand the sensing mechanism of H2O2 in an excited state in all structures are hypochromic and photo-induced charge difference. All analysis shows 1-sim more favorable interacted with H2O2 than 2-sim and 3-sim; and, it is believed that NH2-Cdots may be a potential candidate for sensing the presence of H2O2 to chemosensor applications.
Keyword: carbon dots, gugus amina, hidrogen peroksida, teori fungsional kerapatan, teori fungsional kerapatan-dependen waktu

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