Judul: Sintesis Dan Karakterisasi Suspensi Injectable Bone Substitute Hidroksiapatit Dari Cangkang Keong Bakau (Telescopium sp)- Gelatin.
Abstrak: Telah dilakukan sintesis dan karakterisasi suspensi Injectable Bone Substitute (IBS) berbahan hidroksiapatit-gelatin. Sintesis suspensi IBS dilakukan dengan mencampurkan hidroksiapatit (HAp) dan gelatin dengan rasio komposisi HAp/gelatin sebesar 100/0, 70/30, 30/70, 0/100 dan dilakukan penambahan hydroxyprophyl methylcellulose (HPMC) dengan rasio HPMC:HAp/gelatin sebesar 3:1. Adapun pembuatan HAp berasal dari cangkang keong bakau sebagai sumber kalsium. Berdasarkan hasil analisis XRD dan FTIR terlihat bahwa HAp telah berhasil disintesis. Hal ini ditunjukkan oleh ketepatan parameter kisi lebih dari 99% dan munculnya gugus fungsi fosfat, karbonat dan hidroksil pada spektra FTIR. Penambahan larutan HPMC dalam suspensi IBS mengakibatkan adanya penurunan kristalinitas sampel HAp. Disamping itu, penambahan konsentrasi gelatin dalam suspensi IBS juga menyebabkan penurunan kristalinitas HAp. Dalam penelitian ini, suspensi IBS berhasil disintesis yang ditunjukkan oleh persen injektabilitas yang tinggi pada sampel HAp/gelatin sebesar 70/30 dan 30/70.
Keyword: FTIR, HPMC, uji injektabilitas, XRD

Judul: Synthesis of Injectable Bone Substitute Made from Nanohydroxyapatite/ Chitosan/ Alginate
Abstrak: Tulang merupakan jaringan tubuh yang penting dalam kehidupan manusia. Kerusakan tulang dapat diakibatkan kecelakaan seperti patah tulang atau penyakit seperti osteodegeneratif, tumor dan keropos. Cara untuk memperbaiki kerusakan tulang yaitu dengan implantasi tulang seperti autograf atau allograf. Namun, pengadaan yang terbatas dan resiko penularan penyakit menyebabkan pengganti tulang sintesis banyak dikembangkan. Biomaterial yang sering digunakan yaitu hidroksiapatit, karena memiliki kesamaan dengan mineral alami tulang dan mempercepat regenerasi tulang baru. Kerusakan tulang pada area yang sulit dijangkau dan berbentuk tidak teratur menyebabkan implantasi tulang sulit dilakukan, sehingga dibuat pengganti tulang suntik (injectable bone substitute). IBS merupakan brushite atau mineral apatit yang diperoleh dengan mencampurkan serbuk prekursor kalsium fosfat dengan larutan cair (polimer kitosan-alginat) yang dapat membentuk gel. Komposisi anorganik/organik dan variasi konsentrasi polimer kitosan-alginat berpengaruh terhadap nilai viskositas, injektabilitas, ketahanan dan setting time. Pasta IBS yang memiliki viskositas dan kemapampuan injeksi yang baik serta dapat bertahan saat berada didalam larutan ringer laktat menunjukkan suspensi yang baik untuk pasta IBS. Berdasarkan hasil penelitian sintesis IBS berbahan nanohidroksiapatit/kitosan/alginat berhasil dibuat dengan komposisi terbaik pada perbandingan anorganik/organik 50/50 dan konsentrasi polimer kitosan-alginat 1%. Sampel menunjukkan persen injektabilitas yang tinggi, tidak cepat mengering serta kemampuan mempertahankan posisinya saat berada didalam larutan ringer laktat., Bone is an important body tissue in human life. Bone defect can be caused by accidents such as fractures or diseases such as osteodegenerative, tumor and porous. The way to repair bone defect is by bone implantation such as autographs or allografts. However, limited procurement and the risk of disease transmission have led to the development of synthetic bone substitutes. A frequently used biomaterial is hydroxyapatite, because it has similarities with natural bone minerals and accelerates the regeneration of new bone. Bone defect in hard-to-reach and irregularly shaped areas makes bone implantation difficult, so injectable bone substitutes are made. IBS is a brushite or apatite mineral obtained by mixing calcium phosphate precursor powder with a liquid solution (chitosan-alginate polymer) that can form a gel. Inorganic/organic composition and variation of chitosan-alginate polymer concentration affect viscosity, injectability, durability and setting time. IBS paste that has good viscosity and injectability and can survive while in lactated ringer solution shows a good suspension for IBS paste. Based on the results of the research, the synthesis of IBS made from nanohydroxyapatite/chitosan/alginate was successfully made with the best composition at an inorganic/organic ratio of 50/50 and a chitosan-alginate polymer concentration of 1%. The sample showed a high percentage of injectability, did not dry out quickly and the ability to maintain its position while in lactated ringer solution.
Keyword: bone defect, injectability, polymer complex, setting time, lactated ringers

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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