Judul: Model Matematika untuk Perubahan Suhu dan Konsentrasi Dopant pada Pembentukan Serat Optik
Abstrak: Serat optik merupakan serat yang terbuat dari bahan bening (transparan) yang terdiri atas teras dan selubung. Teras adalah bagian sebelah dalam dan selubung adalah lapisan di luarnya yang memiliki indeks bias, yang dapat memandu perambatan cahaya dengan pemantulan internal pada antarmuka teras-selubungnya. Indeks bias ini diperoleh dengan menambahkan sesuatu yang bersifat penghalus (dopant) di dalam teras. Masalah dalam peneitian ini adalah bagaimana menentukan hubungan antara konsentrasi dopant, suhu, dan jari-jari turbulen pada tungku pembakaran. Tujuan penelitian ini adalah mengkaji model matematika untuk suhu, jari-jari turbulen, dan konsentrasi dopant selama pembentukan serat optik dengan menggunakan asumsi gelombang panjang. Berdasarkan solusi yang diperoleh akan ditentukan keterkaitan suhu, jari-jari turbulen dan konsentrasi dopant terhadap jarak dari input nozzle sepanjang sumbu fiber. Hasilnya disajikan dalam suatu simulasi numerik.
Keyword: Perubahan Suhu, Konsentrasi Dopant, Pembentukan Serat Optik, Serat optik, bahan bening, Teras, indeks bias, perambatan cahaya, pemantulan internal

Judul: Analisis Sifat Isotropik dan Anisotropik Tensor Suseptibilitas Semikonduktor Diamond dan Zincblende Berbasis Teori Grup dan SBHM
Abstrak: Optika nonlinier menjadi metode favorit dalam menginvestigasi permukaan semikonduktor yang mungkin digunakan sebagai piranti optik pada suhu ruang. Material yang dianalisis adalah Si(001) struktur diamond dan GaAs(001) struktur zincblende yang masing-masing memiliki point group octahedral (Oh) dan tetrahedral (Td). Penelitian ini memisahkan tensor suseptibilitas isotropik dan anisotropik pada kasus SHG dan THG serta menganalisis kontribusinya terhadap polarisasi total. Analisis dilakukan menggunakan teori grup dan model ikat hiperpolarisabilitas. Terdapat 6 dan 21 komponen independen tensor isotropik rank-3 dan rank-4 untuk kedua struktur. Pada tensor anisotropik rank-3 terdapat 10 dan 9 komponen tensor untuk struktur diamond dan zincblende. Lalu, terdapat 16 komponen independen tensor rank-4 untuk kedua struktur. Polarisasi total orde ke-2, kontribusi hanya terjadi oleh bagian anisotropik sedangkan bagian isotropik bernilai nol. Polarisasi orde ke-3 bagian isotropik berkontribusi terhadap polarisasi total dan intensitas. Namun kontribusi tersebut hanya vektor konstan. Sedangkan bagian anisotropik memiliki kebergantungan terhadap sudut azimuth.
Keyword: optik nonlinier, generasi harmonik, tensor isotropik

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