Judul: Penentuan Putaran pada Pengering Surya Tipe Rak Berputar dan Pemodelan Pengering dengan Metode Computational Fluid Dynamics
Abstrak: Greenhouse Effect (GHE) Solar Dryer is a transparent wall structure, consists of an absorber plate as solar collector, product holders (rack, tray or batch) that can be rotated vertically, and fans to discharge vapor evaporated from product The GHE solar dryer uses thermal energy source from the sun and biomass combustion. Un-uniformity of rack temperature problem can be solved by rotate the rack within the dryer. The aim of the study is to determine the properly of rack rotation and the temperature distribution by using Computational Fluid Dynamics (CFD) method. There are six scenarios of rack rotation condition to be simulated. The best result is scenario 5 at 135o with rotation per hour shown by the best uniformity of drying temperature indicated by the lowest temperature standar deviation. Validation of CFD result drying temperature whichis performed at eight and twelve o’clock without product, have shown similar trend to the experiment drying temperature distribution indicated by error value of 10%.
Keyword: Rack Temperature, GHE, CFD

Judul: Analysis of Air Temperature Distribution on  Hybrid Greenhouse Effect Dryer-Rack Type using CFD
Abstrak: Alat Pengering Tipe Rak ERK adalah salah satu tipe alat pengering yang banyak digunakan. Permasalahan pada alat pengering tersebut adalah ketidakseragaman aliran udara panas sehingga kadar air bahan yang sudah dikeringkan tidak seragam dan turunnya mutu bahan. Semakin tidak seragam aliran udara, maka energi pengeringan semakin besar. Tujuan penelitian ini adalah untuk mengetahui pola sebaran aliran udara panas di dalam ruang pengering dalam berbagai kondisi serta memberikan rekomendasi modifikasi desain pengering dan perbesaran kapasitas yang tepat. Simulasi aliran udara metode CFD dengan software Ansys dapat memberikan gambaran pola sebaran suhu dan pola aliran udara pada kondisi validasi dan 6 skenario. Rataan error validasi terbesar sebesar 4.172% dan nilai koefisien keseragaman dan variasi sebesar 98.679% dan 1.533%. Skenario 6 merupakan skenario terbaik dengan nilai koefisien keseragaman dan koefisien variasi masing-masing sebesar 99.965% dan 0.044%. Perbesaran kapasitas alat pengering dilakukan dengan merubah volume ruang pengering dari 4.186 m3 menjadi 7.585 m3. Perbesaran kapasitas ditinjau dari segi ekonomis dan kemampuan penukar panas.
Keyword: Pengering, Keseragaman, CFD, Perbesaran, Dryer, Uniformity, CFD, Scale Up

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