Judul: Study of Hydroxyapatite-ZnO-Chitosan Composite Coating on CoCrMo Metal Alloys with Deposition Electrophoresis Method as Antibacterial Implant.
Abstrak: Kinerja osseointegrasi paduan logam CoCrMo yang relatif rendah sebagai implan dapat menimbulkan adanya infeksi sehingga menunda pemulihan pascaoperasi. Salah satu cara pencegahan infeksi tersebut, yaitu menambahkan komposit HAp-ZnO-kitosan yang memiliki efek antibakteri. Efek antibakteri berasal dari kemampuan kitosan dan ZnO dalam menghambat pertumbuhan bakteri. Selain itu, penambahan HAp-kitosan pada komposit juga dapat meningkatkan ketahanan korosi pada implan karena bersifat biokompatibel. Telaah pustaka ini bertujuan meninjau berbagai kajian pustaka mengenai penyalutan komposit HAp-ZnO-kitosan pada logam CoCrMo dengan metode elektroforesis deposisi (EPD) dalam meningkatkan sifat antibakteri dan ketahanan korosi pada implan. Laju korosi menurun setelah proses penyalutan sebesar 0,0035 mpy karena adanya penambahan jumlah kitosan optimum sehingga hasil deposisi yang terbentuk lebih baik. Bakteri gram positif memiliki zona hambat yang lebih luas dibandingkan gram negatif akibat penambahan kitosan dan ZnO yang dapat merusak dinding sel bakteri dengan berbagai mekanisme penghambatan., The relatively low osseointegration performance of CoCrMo metal alloys as implants can cause infection and delay postoperative recovery. One way to prevent this infection is to add a HAp-ZnO-chitosan composite which has an antibacterial effect. The antibacterial effect comes from the ability of chitosan and ZnO to inhibit bacterial growth. Moreover, the addition of HAp-chitosan to the composite can also increase the corrosion resistance of the implant because of its biocompatibility. This study aims to review various literature studies regarding the coating of HAp-ZnO-chitosan composites on CoCrMo metal by deposition electrophoresis (EPD) method in improving the antibacterial properties and corrosion resistance of implants. The corrosion rate decreased after the coating process up to 0,0035 mpy due to the addition of the optimum amount of chitosan so that the deposition results formed became better. Gram-positive bacteria have a wider inhibition zone than gram-negative bacteria due to the addition of chitosan and ZnO which can damage the bacterial cell wall with various inhibitory mechanisms.
Keyword: antibacterial, chitosan, CoCrMo, hydroxyapatite, ZnO

Judul: Coating of Hydroxyapatite-ZnO-Chitosan Composite on Ti6Al4V Metal with Deposition Electrophoresis Method Based on Literature Study
Abstrak: Logam Ti6Al4V umumnya digunakan untuk implan tulang karena memiliki biokompatibilitas yang baik. Namun, penggunaan implan logam dalam jangka waktu yang lama dapat membahayakan tubuh karena dapat mengalami korosi dan infeksi bakteri. Salah satu upaya untuk mengatasi masalah tersebut, yaitu dengan menambahkan komposit HAp-ZnO-kitosan yang bersifat antibakteri dan biokompatibel. Penyalutan komposit HAp-ZnO-kitosan pada logam Ti6Al4V dapat menggunakan metode elektroforesis deposisi (EPD) karena sederhana, murah, dan ketebalan lapisannya dapat dikontrol. Tujuan dari kajian pustaka ini, yaitu meninjau berbagai literatur mengenai proses dan karakterisasi penyalutan komposit HAp-ZnO-kitosan pada logam Ti6Al4V dengan metode EPD. Hasil analisis FTIR menunjukkan bahwa serapan gugus fosfat, hidroksil, amina, dan ZnO mengalami pergeseran karena terdapat interaksi antara HAp, ZnO, dan kitosan. Hasil analisis SEM menunjukkan bahwa morfologi komposit berbentuk partikel kecil yang tersusun rapat di atas matriks kitosan. Laju korosi logam semakin menurun dengan meningkatnya jumlah kitosan yang ditambahkan pada komposit., Ti6Al4V metal is generally used for bone implants because it has good biocompatibility. However, the use of metal implants in the long term can harm the body because it can experience corrosion and bacterial infection. One of the efforts to overcome this problem is by adding HAp-ZnO-chitosan composite which is antibacterial and biocompatible. The coating of HAp-ZnO-chitosan composites on Ti6Al4V metal can use the deposition electrophoresis (EPD) method because it is simple, inexpensive, and the layer thickness can be controlled. This literature review aims to review various literatures regarding the process and characterization of HAp-ZnO-chitosan composite coating on Ti6Al4V metal using the EPD method. The results of the FTIR analysis showed that the absorption of phosphate, hydroxyl, amine, and ZnO groups shifted due to interactions between HAp, ZnO, and chitosan. The results of SEM analysis showed that the morphology of the composite was in the form of small particles that were tightly packed on a chitosan matrix. The metal corrosion rate decreases with increasing the amount of chitosan added to the composite.
Keyword: chitosan, composites, deposition electrophoresis, hydroxyapatite, ZnO

Judul: Utilization of terra/MODIS L1B data for analysis of horizontal wind profile in the troposphere
Abstrak: This study was concerned with horizontal wind derived from data collected with the Moderate-resolution Imaging Spectroradiometer (MODIS) on board the NASA’s Earth Observation System (EOS)-Terra satellite. The aim of this study is to develop a method for the estimation of horizontal wind movement in the troposphere based on Navier-Stokes equation. The method was applied to a calibrated and geolocated Terra/MODIS L1B 1 km data set. The data inputs to estimate surface temperature are retrieved from TIR (Thermal Infrared) bands 31 (10.780 μm to 11.280 μm) and 32 (11.770 μm to 12.270 μm). The obtained surface temperatures were later used to approximate geopotential height on a constant-pressure surface by using the modified Poisson equation. The main assumptions used are the hydrostatic equilibrium, ideal gas law, constant lapse rate and constant acceleration of gravity. Based on the distribution of geopotential height, the pressure gradient force is measured by the gradient of geopotential on an isobaric coordinate to present the horizontal wind profile. For certain topographic areas especially in the mountain ranges, there was a disadvantage of using pressure as a vertical coordinate which lead to inaccuracy. In spite of that, Terra/MODIS L1B data with 1 km spatial resolution can be used to estimate the horizontal wind movement in the troposphere.
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