Judul: Sintesis Paduan Ti-6Al-4Nb sebagai Matrial Implan Pengganti Komponen Tibial
Abstrak: Synthesis of Ti-6Al-4Nb alloy was done by melting using Tri Arc Melting Furnace. Each sample was remelted five times to ensure the homogenity. Aluminum and niobium addition were expected to stabilize α phase and β phase until the αβ-titanium alloy was resulted. Yet based on the experiment, it was α-titanium alloy resulted. α-titanium alloy was a Hexagonal Close Packed (HCP) crystalline structure which would be cracked if deformation non-uniaxial happens. The presence of oxygen in pure titanium significantly increased the hardness of titanium. The addition of aluminum was also able to increase the hardness of titanium alloy because aluminum more stabilize the α phase in the α-titanium alloy. The corrosion ressistance of titanium could be increased by adding aluminum and niobium. Titanium coating with HA/chitosan composite was also proved in decreasing the corrosion rate because it barried direct interaction between titanium alloy and corrotion solution.
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Judul: Penyalutan Nanotube Paduan Logam Ti-6Al-4V dengan Komposit Hidroksiapatit-Kitosan Menggunakan Metode Elektroforesis Deposisi
Abstrak: Paduan logam Ti-6Al-4V digunakan sebagai bahan implan tulang karena sifatnya yang biokompatibel dan tahan korosi. Akan tetapi, kelemahan paduan logam ini tidak bersifat bioaktif dan mudah melepas kation Al dan V ketika diimplankan ke dalam tubuh manusia. Untuk itu, tujuan penelitian ini ialah membentuk struktur nanotube pada permukaan paduan logam Ti-6Al-4V serta menyalutkan komposit hidroksiapatit(HAp)-kitosan pada nanotube paduan logam Ti-6Al-4V. Nanotube dibentuk melalui metode anodisasi dalam larutan NH4F 5% pada tegangan 20 V selama 1 jam. Hasil pencirian dengan mikroskop elektron payaran menunjukkan nanotube terbentuk secara heterogen dan tidak seragam dengan diameter lubang 2‒3 μm. Komposit HAp-kitosan disalutkan pada nanotube tersebut dengan metode elektroforesis deposisi pada tegangan 100 V selama 1 jam. Hasil penyalutan merata, tidak ada perbedaan yang cukup jelas antara penyalutan komposit HAp-kitosan pada bagian nanotube dan bagian tanpa nanotube. Hasil pencirian difraksi sinar-X dan inframerah transformasi Fourier menunjukkan komposit HAp-kitosan telah menyalut paduan logam Ti-6Al-4V.
Keyword: anodisasi, hidroksiapatit, kitosan, nanotube, Ti-6Al-4V

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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