Judul: Iklim nusa tenggara hubungannya dengan southern oscillation (SO)
Abstrak: Bertitik tolak dari keadaan iklim Nusa Tenggara yang selalu diidentikan dengan keadaan yang kering maka perlu adanya suatu gambaran keadaan iklim Nusa Tenggara yang berdasarkan variasi unsur dan faktor pembentuk. iklimnya. Keadaan kering di Indonesia sering dihubungkan dengan El Nino dan suatu embutan perbedaan tekanan di permukaan laut di Pasifik Selatan bagian Timur dengan daerah Indonesia-Australia (Southern Oscillation) fase negatif. Deskripsi iklim Nusa Tenggara digunakan nilai rata-rata, simpangan baku, dan koefisien keragaman. Sedangkan hubungan antara iklim Nusa Tenggara dengan Southern Oscillation digunakan korelasi silang lag k musim (cross-correlation lag k). Untuk menggambarkan Southern Oscillation (SO) digunakan SOI (Southern Oscillation Index). Nilai SOI dibentuk dari selisih tekanan di permukaan laut antara tiga tempat di Pasifik Timur dengan Jakarta (musiman). Variasi unsur iklim Nusa Tenggara menunjukkan nilai yang tinggi untuk unsur iklim curah hujan, dimana koefisien keragamannya mencapai 316%. Sedangkan unsur iklim lainnya relatif rendah berkisar dari 0.06% hingga 29.7%. Tipe iklim Nusa Tenggara menurut klasifikasi Koppen adalah Aw dan menurut Schmidt-Ferguson adalah Tipe D, E dan F. Hubungan antara iklim Nusa Tenggara (curah hujan) dengan SO nyata pada lag 1 dan 2 musim, dimana pengaruh SO nyata terhadap curah hujan 1 hingga 2 musim sesudah- nya. Kekeringan yang terjadi di Nusa Tenggara tidak selalu diakibatkan oleh El Nino dan SO fase negatif, tetapi ditentukan oleh perbedaan tekanan antara benua Asia dan benua Australia…
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Judul: Keterkaitan fase Indeks Osilasi Selatan (SOI) terhadap curah hujan di Das Citarum
Abstrak: Indeks Osilasi Selatan (SOI) adalah anomali perbedaan tekanan udara permukaan antara Tahiti di kepulauan Polinesia-Perancis, dengan tekanan udara permukaan di Darwin, Australia. SOI yang positif besar (tekanan udara di Tahiti jauh lebih tinggi dari pada tekanan udara di Darwin) berkaitan dengan kondisi La Nina, SOI yang negatif besar (tekanan udara di Tahiti jauh lebih rendah dari pada tekanan udara di Darwin) berkaitan dengan kondisi El Nino.
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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