Judul: Pembuatan Film Tipis Barium Stronsium Titanat Didadah dengan Cerium dan Analisis Rietveld Menggunakan MAUD
Abstrak: Film tipis Barium Stronsium Titanat (BaSrTiO3/BST) dengan larutan 1 M telah berhasil di sintesis di atas substrat Si (100) tipe p dengan metode Chemical Solution Deposition (CSD) melalui spin coating dengan kecepatan putar 8000 rpm. Film BST di annealing pada suhu 8500C selama 8 jam. Karakterisasi sifat optik dilakukan terhadap film BST murni dan dengan konsentrasi pendadah Cerium Oksida (CeO2) sebesar 0%, 2%, 6%. Hasil penelitian menunjukan bahwa nilai bandgap tidak cukup baik namun film BST murni dengan konsentrasi pendadah Cerium Oksida (CeO2) 4% menghasilkan nilai bandgap yang mendekati nilai literatur sebesar 3.10 eV. Berdasarkan analisis Rietveld dengan menggunakan Material Analysis Using Diffraction (MAUD) didapatkan bahwa BST murni dan pendadah memiliki struktur kristal berbentuk kubus dengan parameter kisi berturut-turut sebesar 4.05437 Å; 4.059837 Å ; 4.06175 Å ;4.065212 Å, dan rata-rata ukuran kristalnya sebesar 588.7530, 588.5976, 475.4838, 843.7147 dalam satuan Å.
Keyword: annealing, bandgap, BaSrTiO3, CSD, CeO2

Judul: Pembuatan dan Karakterisasi Film Barium Stronsium Titanat Didadah dengan Carbon Dot
Abstrak: Film Barium Stronsium Titanat (BaSrTiO3) yang didadah carbon dot dengan variasi pendadah 0%, 2%, 4%, 6% menggunakan metode CSD dengan bantuan spin coating dengan kecepatan putar 8000 rpm telah berhasil dibuat diatas substrat silikon tipe-p 100. Film ini di annealing dengan suhu 850 °C dan ditahan selama 8 jam. Film BaSrTiO3 pada konsentrasi pendadah 0%, 2%, 4%, 6% carbon dot dikarakterisasi UV-VIS, XRD, SEM-EDX sehingga menghasilkan energi bandgap secara berurutan sebesar 2.72 eV; 2.85 eV; 3.7 eV dan 3.8 eV. Hasil karakterisasi XRD menunjukkan bahwa struktur kisi BaSrTiO3 adalah kubus dengan parameter kisi a=b=c secara berurutan sebesar 4.066945 Å ; 4.06868 Å ; 4.072155 Å dan 4.077379 Å. Hasil karakterisasi SEM-EDX menunjukkan bahwa pada morfologi permukaan film BaSrTiO3 ukuran butirnya cukup homogen dan didapatkan komposisi atom yang sesuai yaitu Ba, Sr, Ti, O, dan C.
Keyword: annealing, bandgap, BaSrTiO3, carbon dot, spin coating

Judul: Phylogeography and Species Limits in the Papuan White Snake (Micropechis ikaheka) (Reptilia: Serpentes: Elapidae)
Abstrak: Papua white snake, Micropechis ikaheka, has been distingushed into two subspecies M.i. ikaheka and M.i. fasciatus. However, due to lack of data on their morphology, distribution and ecology, both subspecies often ignored in scintific discussions and refers only byas , Micropechis ikaheka. This study was designed to document the differences between M.i. ikaheka and M.i fasciatus by using scales characteristics and reproductive organ or hemipenes. The study also examine, zoogeography, habitat, diet and cannibalism of both subspecies to better understanding the the ecology of one of the most venomous snakes in the world. This study consists of three topics with method and also different in the size samples, respectively. The first study is the histology and microtopography of the skin were studied using paraffin method and Scanning Electron Microscope (SEM). The second is the hemipenis were examined by following Myers and Cadle (2003), and Zaher and Prudente (2003). The third is the abdominal surgery was carried out to document diet type and the investigate phenomenon of cannibalism in the snake. Specimens for this study came from the collection from Museum Zoologicum Bogoriense (MZB) and Universitas Negeri Papua’s Laboratory (LZU). The research result also indicated that the markers of skin and hemipenis described the same structure and microornamentation in all M. ikaheka groups being compared. Based specimens examined morphological descriptions do not s support the further differentiation in Micropechis. In short, two markers that used in this study could not sufficiently indicate the differences in the level of species and subspecies of M. ikaheka. The study, however, were able to delineate zoogeography and skin color patterns, which fall into four groups: M. i. ikaheka; M. i. fasciatus. M. i. ssp. “intermediate”; and M. i. ssp “black”. This study also revealed that color variations did not overlap in their geographic distribution. It is therefore, it suggested that environmental factors may contribute to the skin color variations. It also assumed that habitat discontinuous and biogeography factors may also cause the loss of the connection between the original populations (vicarians) or follow colonization events (dispersal). The examined of 22 stomach contents of M. ikaheka shows this species is carnivorous, and prey on vertebrates such as amphibians, fish, reptiles, and Mammals. These snakes are opportunistic predators since they prey on all that can be captured, but mainly reptiles (61.5%), followed by mammals and fish (both 15.4%), and amphibians (7.7%). Although categorized as terrestrial animal, the diet study showed that M. ikaheka snakes often go into the water to hunt for fish (the sample from Yapen island), including eel (the sample from Aru island). Based on prey items indentified, there is evidence that M. ikaheka is cannibal. At this time, there still no record on reason for cannibalism, but it is assumed that cannibalism was due to competition between populations and means to control population.
Keyword: geographic variation, white snake, papua