Judul: Pelapisan Hidroksiapatit pada Paduan Logam CoCrMo Terlapis Titanium Nitrida Menggunakan Metode Biomimetik
Abstrak: Bone implants is a way to cure broken bones which is being developed. The implants can be made of metals, ceramics and polymers. Metallic materials commonly used are titanium (Ti), stainless steel, and metal alloys. This study used Co-based alloys, i.e. CoCrMo coated with titanium nitride (TiN) which was then coated on hidroxyapatite (HAp). The HAp coating on the surface of CoCrMo alloy was done by biomimetic methods, first by soaking the metal alloys in simulated body fluid (SBF) solution for 18, 24, and 36 hours. The immersion in the SBF solution produced white coat on the surface of the metal alloy. The layers formed were analyzed by scanning electron microscope (SEM) and characterized by x-ray diffractometer (XRD). Based on the SEM results of 36 hours treatment, the morphology of apatite crystal formed fine grains. According to XRD result, there were HAp peaks at angles 2θ 31.86, 32.25, dan 39.48. However, there were also CaCO3 peaks at angles 2θ 29.46, 36.04, and 46.79. It indicated the pure HAp is not yet formed.
Keyword: hydroxyapatite, Bogor Agricultural University (IPB), CoCrMo-TiN, biomimetic

Judul: Optimisasi Penyalutan Hidroksiapatit pada Paduan CoCrMo denganMetode Elektroforesis Deposisi
Abstrak: CoCrMo alloy has good biocompatibility and so it can be used as a substitute for bone damage (implant). However, other material isneeded to improve the biocompatibility of the CoCrMo. Hydroxyapatite can be used to coat the CoCrMo alloys to improve the biocompatibility of the CoCrMo. Hydroxyapatite can stimulate the growth of bone tissue surrounding the implant. Coating hydroxyapatite on the CoCrMo alloys was carried out using electrophoreticdeposition method by varying a number of variables, i.e. ratio of solution volume (ethanol-triethanolamine), pH, voltage, and time. The use of such variables was intended to get an optimum condition of the CoCrMo alloy coating. Test on the strength of hydroxyapatite layer in NaCl 0.9% infusion solutionshowed an optimum coating at pH 7, voltage 120V, for 30 minutes with a ratio of ethanol:TEA (50:2) mL.The test was done by soaking the hydroxyapatite-coated metal in 0.9% NaCl for 5 hours.Identification in phase diffraction conformedthe diffraction pattern as JCPDS hydroxyapatite.
Keyword: hydroxyapatite., CoCrMo alloy, electrophoretic deposition

Judul: Klasifikasi genre musik menggunakan Learning Vector Quantization (LVQ)
Abstrak: Radio stations and music television have a milion of music tapes. A lot of musical genres create a problem when people wants to determine the right genre of a new kind of music. To classify the musical genre is not an easy task, because the musical genre is really difficult to standardization. Automatic musical genre classification can assist the human role in that process and help people to searching for the song acording to the genre that people want. This research using Mel Frequency Coefficient Cepstrum (MFCC) to obtain feature extraction. Learning Vector Quantization (LVQ), one kind of artificial neural network used for classification method. The number of genres that are used were four kind of musical genre, that is rock, classic, keroncong, and jazz with four different duration that is 5 second, 10 second, 20 second and 25 second. This research using k- fold cross validation to distribute dataset for training and testing set with the number of folds as much as 2 until 10 fold. This research succesfully implemented MFCC feature exraction and classification using LVQ. Based on this research, the accuracy of the classification using Learning Vector Quantization reaches 93,75% for the four type musical genre. The highest accuracy value was obtain from the experiments with a duration of 10 second and the number of fold 4. Training time for each duration is 30 minute for 5 second music duration, 45 minute for 10 second music duration 120 minute for 20 second music duration and 150 minute for 25 second music duration.
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