Judul: Variabilitas Arus di Sekitar Selat Sunda Tahun 2007-2010 dari Hasil Model INDESO
Abstrak: Model output of high-resolution (1/12°) ocean general circulation model from INDESO project between 2007-2012 were used to investigate the structure and variability of currents at two locations around the Sunda Srait, one location is in Java Sea (JS) and the other is in Indian Ocean (IO) side. Model sea surface height (SSH) is validated with altimetry data, which shows a high correlation coefficient of 0.90 in the IO and 0.76 in JS. In general, both model and altimetry data indicate that SSH in JS is always higher that found in IO. However, between November-January each year, there exists a reversal flow northward in Sunda Strait, which may be related to arrival of coastally trapped Kelvin waves. An intensification of current appears near surface layer both in JS and IO. Analysis of power spectral density energy exhibits a wide range of current variability from intra-seasonal, semi-annual and annual time-scales. Power density energy of zonal current component is much stronger that that meridional component, and amplitude of energy is much stronger in IO it show that current in IO is stronger than JS. Cross correlation analysis show that there is strong relation between between JS and IO currents fluctuation which showed by coherence value between two areas of 0,99.
Keyword: Sunda Strait., Power spectral density analysis, Ocean general circulation model 1/12, Current vertical structure, Current Variability

Judul: Struktur dan Variabilitas Arus di Laut Sulawesi
Abstrak: Laut Sulawesi merupakan salah satu pintu masuk Arus Lintas Indonesia (Arlindo) yang membawa 15 juta meter kubik per detik massa air hangat dari Samudra Pasifik ke Samudra Hindia melalui berbagai laut dan selat Indonesia. Pola sirkulasi di basin Sulawesi masih belum dipahami secara baik. Penelitian ini bertujuan mendeskripsikan pola sirkulasi, struktur menegak arus, serta variabilitas arus dan koherensi antara fluktuasi arus-masuk dengan arus-keluar. Metode analisis data deret waktu digunakan untuk menganalisis data keluaran model sirkluasi laut dari konfigurasi INDESO tahun 2007-2012. Hasil penelitian menunjukkan pola arus di Laut Sulawesi dicirikan oleh suatu lintasan sumbu utama arus kuat yang mengalir dari pintu masuk sisi timur laut ke arah barat daya, yang membentur sisi Kalimantan, kemudian berbelok ke arah tenggara dan masuk ke Selat Makassar. Lintasan arus utama ini sebagai pangkal dari Arlindo. Di sisi utara dan selatan dari lintasan arus utama terbentuk pusaran siklonik (wilayah utara) dan pusaran anti-siklonik (wilayah selatan). Struktur vertikal arus dicirikan oleh intensifikasi arus maksimum sekitar 60 cm/detik pada kedalaman 75 m – 300 m (kedalaman termoklin). Fluktuasi arus bervariasi dalam rentang periode skala intra-musiman, tahunan, dan antar-tahunan. Spektrum densitas energi signifikan terdapat variasi intra-musiman. Terdapat koherensi yang signifikan antara arusmasuk (komponen zonal) dengan arus-keluar (meridional) pada skala-waktu intramusiman
Keyword: Sulawesi Sea, NEMO Model Output, INDESO Configuration, Time Series Analysis

Judul: Synthesis of Chicken Eggshells-Based β-Tricalcium Phosphate Bioceramics and Their Biocompatibility Test as A Tooth Filler
Abstrak: Preservation of alveolar bone following tooth extraction is an important step in dental practices before dental implant placement. This study reported synthesis of β-Tricalcium Phosphate (β-TCP) bioceramics and its biocompatibility test as a tooth filler to maintain the desired alveolar ridge dimension and stimulate the bone healing processes in the area of tooth loss. β-TCP bioceramics was resulted directly from precipitation of calcinated chicken eggshells as calcium source and phosphoric acid. The corresponding β-TCP was mixed with chitosan 2% to get β-TCP pellet for biocompatibility testing. Biocompatibility testing of β-TCP on lower incisor was performed in rabbits and sheep as animal model. In this study, the x-ray diffraction (XRD) profiles showed that 1000 oC calcinated chicken eggshells correspond to calcium oxide (CaO). There was also transformation phase of CaO into Ca(OH)2 observed after more than three months stored. The XRD profiles proved that obtained β-TCP bioceramics by precipitation has the same pattern with that of reference data base and commercial β-TCP. Fourier transform infrared (FTIR) spectra were completely consistent with the result of crystallization processes observed by XRD measurements. Moreover, the purity of the product shown by the atomic absorption spectroscopy (AAS) resulted in Ca/P ratio of 1.48 which was closed to that of standard β-TCP ceramics. The repeatable XRD peaks patterns and FTIR spectra obviously showed the sample reproducibility. Sheep’s alveolar socket that is filled with the corresponding β-TCP demonstrated the expected results. The x-ray radiograph of sheep’s jaw indicated no change on mesio-distal of the edentulous area. Moreover, the histological results were completely consistent with the x-ray radiograph and macroscopic result which is proved by the formation of new bone. In the contrary with sheep’s result, histological results showed no tooth growth on rabbit proved by the presence of lipid and collagen on the extraction site. This result did not correspond to the x-ray radiograph and macroscopic results that demonstrated the tooth growth and erupted tooth. It is clear that the corresponding β-TCP could minimize the bone loss and maintain the dimension of alveolar ridge.
Keyword: β-tricalcium phosphate, chicken eggshells, rabbit, sheep, tooth filler