Judul: Study of Biphasic Calcium Phosphate Ceramics and HA-Chitosan Composite Implanted into Sheep’s Bone
Abstrak: Biphasic Calcium Phosphate (BCP) biomaterials are recognized as biodegradable, bioresorbable, and osteoconductive material and, therefore, it is suitable for filling bone defects to aid regeneration process of new bone tissue. This study aimed to synthesize BCP ceramics by precipitation method and observe bone growth using BCP ceramics and HA-Chitosan composite implanted into sheep’s bone. BCP ceramics was prepared by precipitation of Na2HPO4.2H2O which was dropped by CaCl2.2H2O at temperature 700C with various molar ratios and various volume of solution. Molar ratio of Ca and P was variated approximately 0.2M:0.2M and 0.334M:0.2M while various volume of solution was 50 ml and 100 ml. BCP ceramics was formed which was indicated by mass of precipitate and the result showed that sample with greater molarity of Ca was resulting in bigger mass precipitate. It showed that higher molarity of Ca/P tends to be more mass precipitate. The X-Ray Diffraction results showed that BCP 100 ml with molar ratio Ca/P about 0.334M:0.2M had the expected characteristics of implant material for in vivo experiment into sheep’s bone. Moreover, it showed the consistency of sample which indicates that it was a reproducible biomaterial. This result was also supported by Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) characterization. In vivo study of BCP ceramics and HA-Chitosan composite showed that bone recovery without bone graft (control) was more complete than that with BCP and HA-Chitosan bone grafts. Based on pathological evaluation, the results indicated that BCP ceramics was biodegradable and bioresorbable but less osteoconductive. In the contrary, HA-chitosan composite was not biodegradable and bioresorbable but more osteoconductive. Moreover, BCP bone graft was more readily resorbed by the body than HAChitosan. Resorption of HA-Chitosan bone graft was very slow but new tissue growth was faster than that of BCP bone graft. In contrary, resorption of BCP bone graft was very fast but new tissue growth was very slow.
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Judul: Characterization of Biphasic Calcium Phosphate with Ratio of 70/30 Before and After Implanted into Sheep’s Bone
Abstrak: Nowadays, biphasic calcium phosphate is used for biomaterial to cure bone damage. This study focuses only on mixing ratio of 70% mass of hydroxyapatite and 30% mass of tricalcium phosphate with chitosan and acetic acid as the hardening. Pure HA had done by wet precipitation in sintering process at temperature of 900 oC while β-TCP is at temperature of 1000 oC. Mechanical method of BCP is proven to be a non toxic material and could absorb by the mineral body. Implanted BCP was characterized with XRD, FTIR, SEM-EDS and bone characterization with Vickers Hardness. In XRD analysis, the result is adding chitosan makes BCP less accuracy of pure HA and β-TCP. FTIR shows composition of BCP sample with HA, TCP, H2O, AKB, and N-H bending. SEMEDS releases ratio Ca/P of implant in post operation has irregularity caused by interaction with bone that supported by Vickers Hardness number. HV for 1 month of post operation have larger number for both implanted and control bone.
Keyword: β-TCP, HA, BCP

Judul: Variabilitas Transpor Arlindo Laut Flores dan Kaitannya dengan ENSO
Abstrak: Air Arlindo yang masuk ke Indonesia sebagian besarnya dilewatkan Laut Flores. Variasi volume transport Arlindo dipengaruhi oleh fenomena anomali iklim interannual seperti El Nino Southern Oscillation (ENSO). Hasil studi terdahulu menyimpulkan terjadinya La Nina meningkatan jumlah transport Arlindo, sedangkan El Nino melemahkan transport Arlindo. Untuk memahami lebih lanjut keterkaitan ENSO dengan variabilitas transport Arlindo dilakukanlah penelitian menggunakan data hasil model INDESO dan hasil observasi satelit dengan rentang waktu 2008 hingga 2015. Penelitian dilakukan di Laut Flores dengan mengkaji bagian barat (119.5oBT) dan bagian timur (123oBT) untuk melihat volume Arlindo yang masuk ke dan keluar dari Laut Flores. Analisis sirkulasi dilakukan dengan menghitung rataan komponen arus dan suhu permukaan laut secara tahunan dan pada rentang tahun ENSO untuk melihat pola sirkulasi perairan. Estimasi volume transpor dihitung dari transek di pintu barat dan pintu timur. Deret waktu volume transpor Arlindo Flores kemudian dianalisis variabilitasnya dengan analisis penapisan lolos-pita(band-pass filter) dan transformasi wavelet sinambung (Continous Wavelet Transform). Hasil penting studi ini menunjukkan bahwa sumber utama Arlindo Flores berasal dari pembelokan Arlindo Makassar dan Arlindo pintu timur Indonesia yang masuk melalui terusan Lifamatola. Kecepatan Arlindo Flores di lapisan tercampur menguat pada musim barat sebaliknya di lapisan termoklin Arlindo Flores menguat pada musim timur. Sumbu utama Arlindo Flores didominasi oleh komponen arus zonal serta mengalami intensifikasi dan bergerak menyusur bagian utara Kepulauan Nusa Tenggara. Fluktuasi Arlindo Flores pada skala-waktu interannual menunjukkan volume transport maksimum terjadi pada tahun La Nina (November 2008-Maret 2009), sedangkan volume transpor minimum terjadi pada tahun El Nino (November 2014-Desember 2015). Struktur menegak Arlindo lebih kuat di kedalaman antara permukaan sampai 400 m. Variabilitas Arlindo Flores menandakan adanya fluktuasi pada periode intraseasonal, semi-annual, dan annual. Fluktuasi Arlindo skala interannual muncul jelas dari hasil penapisan lolos-pita, dimana fluktuasinya terlihat signifikan di kedalaman termoklin.
Keyword: Arus Lintas Indonesia, Laut Flores, ENSO, INDESO model, variabilitas volume transpor