Judul: Peran Pulau Sangiang terhadap Pola Sirkulasi Laut dan Analisis  Trajektori Larva Karang di Selat Sunda
Abstrak: Pulau Sangiang sebagai kawasan taman wisata alam di kawasan Selat Sunda, sesuai dengan SK Menteri Kehutanan No. 698/Kpts-II/1991 pada tahun 1991, berada di bagian tengah selat dan berbatasan langsung dengan Laut Jawa di sisi utara selat, serta dengan Samudera Hindia di sisi selatannya. Sirkulasi laut di kawasan Sangiang diduga dipengaruhi oleh dinamika kedua perairan tersebut. Faktor oseanografi sangat mempengaruhi lingkungan di perairan Pulau Sangiang. Salah satu faktor fisik yang memengaruhinya adalah arus laut. Tujuan penelitian ini adalah mendeskripsikan pengaruh Pulau Sangiang terhadap pola sirkulasi arus laut di Selat Sunda dan mendeskripsikan prediksi arah sebaran larva karang di Pulau Sangiang dengan metode analisis trajektori. Tool yang digunakan untuk analisis pola arus di Pulau Sangiang adalah Coastal and Regional Ocean Community (CROCO). Hasil model CROCO digunakan dalam analisis trajektori partikel di perairan menggunakan Ichthyop. Hasil eksperimen numerik adanya Pulau Sangiang menyebabkan arus yang masuk dari Laut Jawa bergerak lebih kencang dan terjadi pembelokan ketika melewati pulau. Simulasi trajektori sebaran larva karang menunjukkan larva bergerak mengikuti pola sirkulasi arus yang terbentuk di Selat Sunda. Larva yang terbawa arus diprediksikan akan tumbuh di wilayah pesisir Teluk Lampung dan pesisir pulau-pulau kecil yang ada di Selat Sunda., Sangiang Island as a natural tourist park in the Sunda Strait area, in accordance with the Decree of the Minister of Forestry No. 698/Kpts-II/1991 in 1991, is in the middle of the strait and directly adjacent to the Java Sea on the north side of the strait, and the Indian Ocean on the south side. Ocean circulation in the Sangiang area is thought to be influenced by the dynamics of the two waters. Oceanographic factors greatly affect the environment in the waters of Sangiang Island. One of the physical factors that influence it is ocean currents. The purpose of this study was to describe the effect of Sangiang Island on the circulation pattern of current circulation in the Sunda Strait and to describe the distribution direction of coral larvae on Sangiang Island using the trajectory analysis method. The tool used for analysis of current patterns on Sangiang Island is Coastal and Regional Ocean Community (CROCO). The results of numerical experiments on the existence of Sangiang Island causes the current flow from the Java Sea move faster and there was a deflection when passing through the island. The trajectory simulation of coral larvae distribution shows that the movement of larvae following the current circulation pattern formed in the Sunda Strait. Larvae carried by current are predicted grow in the coastal area of Lampung Bay and the coast of small islands in the Sunda Strait.
Keyword: Current, analysis trajectory, coral larvae, Sangiang island, CROCO model

Judul: Analisis Hubungan Antara Tutupan Karang Keras dan Komunitas Bentik dengan Kelimpahan Ikan di Pulau Sangiang, Provinsi Banten
Abstrak: Pulau Sangiang merupakan pulau konservasi yang memiliki biodiversitas laut yang tinggi pada ekosistem terumbu karang. Variasi karang keras dan ikan karang yang tinggi menjadi daya tarik utama untuk wisata bahari, seperti penyelaman. Namun demikian, Pulau Sangiang rentan terhadap gangguan lingkungan alami seperti tsunami dan antropogenik seperti laju sedimentasi yang tinggi dan pariwisata bahari yang merusak karang. Transplantasi karang dilakukan untuk merehabilitasi dan melindungi ekosistem terumbu karang yang mengalami kerusakan. Tujuan dari penelitian ini adalah menganalisis hubungan karang keras dan komunitas bentik dengan kelimpahan ikan pada wilayah timur Pulau Sangiang. Lima kategori komunitas bentik ditemukan, dengan persentase tutupan tertinggi dimiliki oleh HC (52-90%) dan DCA (6-25%). Ditemukan 11 lifeform HC, dengan persetase tutupan tertinggi dimiliki oleh CF (34-59%) dan ACB (2-47%). Kelimpahan ikan karang yang ditemukan berkisar dari 1.195 individu di Legon Bajo dan 751 individu di Legon Waru. Kelompok trofik ikan dengan kelimpahan tertinggi dimiliki oleh omnivora dan planktivora. Hasil analisis koresponden (CA) memberikan informasi sebesar 78,17% dari sumbu 1 (F1), sumbu 2 (F2), dan sumbu 3 (F3). Pengelompokan menunjukkan ikan koralivora, karnivora, dan omnivora berkaitan erat pada wilayah dengan tutupan HC yang tinggi, sementara ikan herbivora berkaitan erat pada wilayah dengan tutupan karang mati dan alga yang tinggi., Sangiang Island is a conservation island that has high marine biodiversity in coral reef ecosystems. The high variety of hard corals and reef fish is the main attraction for marine tourism, such as diving. However, Sangiang Island is vulnerable to natural environmental disturbances such as tsunamis and anthropogenic disturbances such as high sedimentation rates and marine tourism which damages corals. Coral transplants are carried out to rehabilitate and protect damaged coral reef ecosystems. The purpose of this study was to analyze the relationship between hard corals and benthic communities with fish abundance in the eastern region of Sangiang Island. Five benthic community categories were found, with the highest percentage of cover belonging to HC (52-90%) and DCA (6-25%). 11 HC lifeforms were found, with the highest percentage cover belonging to CF (34-59%) and ACB (2-47%). The abundance of reef fish found ranged from 1,195 individuals in Legon Bajo and 751 individuals in Legon Waru. The trophic group of fish with the highest abundance belongs to omnivores and plankton. Correspondent analysis (CA) results provide information about 78.17% of axis 1 (F1), axis 2 (F2), and axis 3 (F3). Grouping shows that coralivorous, carnivorous, and omnivorous fish are closely related to areas with high HC cover, while herbivorous fish are closely related to areas with high dead coral and algae cover.
Keyword: Benthic Communities, Hard Coral, Fish Tropic Group, Grouping

Judul: Sintesis Paduan Ti-6Al-4Nb sebagai Matrial Implan Pengganti Komponen Tibial
Abstrak: Synthesis of Ti-6Al-4Nb alloy was done by melting using Tri Arc Melting Furnace. Each sample was remelted five times to ensure the homogenity. Aluminum and niobium addition were expected to stabilize α phase and β phase until the αβ-titanium alloy was resulted. Yet based on the experiment, it was α-titanium alloy resulted. α-titanium alloy was a Hexagonal Close Packed (HCP) crystalline structure which would be cracked if deformation non-uniaxial happens. The presence of oxygen in pure titanium significantly increased the hardness of titanium. The addition of aluminum was also able to increase the hardness of titanium alloy because aluminum more stabilize the α phase in the α-titanium alloy. The corrosion ressistance of titanium could be increased by adding aluminum and niobium. Titanium coating with HA/chitosan composite was also proved in decreasing the corrosion rate because it barried direct interaction between titanium alloy and corrotion solution.
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