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: Pelapisan hidroksiapatit pada logam CoCrMo dengan metode biomimetik
Abstrak: Coating of hydroxyapatite (HAp) is an attempt to improve biocompatibility and prevent the cytotoxic properties of CoCrMo metal commonly used as an implant material . HAp coating was carried out by using a biomimetic method by immersing the metal in a simulated body fluid (SBF) solution. The SBF concentration was varied into 4 types, SBF A (SBF without NaHCO3 and MgCl2.6H20), SBF B (2.5× SBF), SBF C (5× SBF), and SBF D (7.5× SBF). After 48 hours soaked in SBF B, C, and D solutions, the HAp was uniformly spreaded on the surface. The thicknesses were 50, 100 and 200 μm, respectively for SBF B, C and D as measured by SEM. The apatite from each coated metal characterize by using XRD. The results indicated the presence of HAp coating by immersion in SBF C. This best coating condition (5xSBF) was performed on the nitridated CoCrMo metal to increase its biocompatibility, however the HAp was not formed.
Keyword: SBF, hydroxyapatite, CoCrMo, biomimetic

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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