Judul: Pengaruh Pendadah La2O3 pada Sifat Optik dan Struktur Kristal Ba0.55Sr0.45TiO3
Abstrak: Film tipis Ba0.55Sr0.45TiO3 (BST) murni dan BST yang didadah La2O3 (BSLT) dengan variasi pendadah 2%, 4%, dan 6% telah berhasil ditumbuhkan di atas substrat Si (111) tipe-p dengan menggunakan metode Chemical Solution Deposition (CSD). Film BST dan BSLT dibuat dalam konsentrasi 1 M. Film tersebut ditumbuhkan dengan tiga kali pelapisan menggunakan teknik spin coating pada kecepatan putar 3000 rpm selama 30 detik. Film kemudian diannealing pada suhu 850 0C selama 15 jam. Film dikarakterisasi menggunakan spektrofotometer Vis-NIR untuk mengetahui sifat optik berupa analisis nilai absorbansi, reflektansi, indeks bias dan energy gap. Penambahan bahan pendadah pada film BST menyebabkan nilai absorbansi, indeks bias dan energy gap meningkat. Semua film tipis ini mengabsorbsi dan mereflektansikan cahaya di daerah cahaya tampak. Instrumentasi XRD digunakan untuk mengetahui struktur kristal film. Hasil menunjukkan bahwa penambahan pendadah lantanum oksida mengakibatkan nilai parameter kisi menjadi lebih kecil dan terbentuk kristal kubus.
Keyword: barium strontium titanat, lantanum oksida, sifat optik, struktur kristal

Judul: Struktur kristal dan sifat listrik film Ba0.55Sr0.45TiO3 dengan variasi pendadahan La2O3
Abstrak: Telah dibuat film Ba0.55Sr0.45 TiO3 di atas substrat Silikon (1 1 1) tipe-n dengan menggunakan metode Chemical Solution Deposition dan spin coating berkecepatan 3000 rpm selama 30 detik dalam kelarutan 1 M dengan variasi pendadahan La2O3 sebesar 0%, 1%, 3%, dan 5%. Annealing dilakukan pada suhu 850 °C selama 15 jam dengan laju kenaikan 1.67 °C/menit. Karakterisasi struktur berupa pengujian XRD dilakukan pada sampel pendadahan 3%. Puncak-puncak difraksi sinar-X menunjukkan partikel film memiliki distribusi orientasi kristal. Struktur kristal BST berbentuk tetragonal. Sedangkan hasil uji sifat listrik menunjukkan karakteristik film tipis BST termasuk material semikonduktor yang memiliki sifat kapasitor. Pendadahan La2O3 menaikkan konstanta dielektrik film.
Keyword: annealing, BST, La2O3, sifat listrik, struktur kristal, Hasil annealing, Konduktivitas likstrik, Konstanta dielektrik

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