Judul: Aktivitas Antioksidan Zeolit Alam Terpilar-TiO2
Abstrak: Utilization of zeolite in Indonesia is still limited. However, in the field of agriculture and environmental processing technology, zeolites are widely known as reliable adsorbent materials. This study aimed to determine the antioxidant activity of TiO2-pillared zeolite by using 1,1-diphenyl-2-picrylhidrazyl. The natural zeolites were activated with variation of acid concentration and heating temperature. The pillarization product of the best activated zeolite were characterized by X-ray diffractometer (XRD) and scanning electron microscope (SEM-EDX). The antioxidant activity of natural zeolite increased after being pillared with TiO2. XRD diffractogram showed that Sukabumi’s natural zeolite was a mixture of clinoptilolite and mordenite types with 53.03% crystallinity, whereas the SEM-EDX result showed that the composition of TiO2 increased 13.82% in zeolite activated at 400 oC and 4.34% in zeolite activated with 2.0 M acid concentration. These increase promoted the antioxidant activity of 14.80% and 6.17%, respectively.
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Judul: Aktivitas Antioksidan Zeolit Alam Terpilar-Fe2O3
Abstrak: Pillarization of zeolite with iron oxide has been carried out in order to increase the adsorption ability and its characteristics. Generally, natural zeolite have poor crystallinity and low catalytic activity, heterogenous pore size, and high impurities, so it needs to be activated and modified. The aims of this research were to study the effect of activation of Sukabumi’s natural zeolite with calcination and acidification as well as the effect of modification of activated zeolite with pillarization technique by using Fe2O3. The property of Fe2O3 semiconductor was expected to increase the antioxidant activity of the natural zeolite through 1,1-diphenyl-2-picrylhydrazyl method. The characterization showed that Sukabumi’s natural zeolite was clinoptilolite type and its antioxidant activity was increased after being pillared with Fe2O3, 17.73% and 27.29%, respectively for zeolite activated with calcination at 400 °C and with HCl 2.0 M.
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Judul: Pemodelan chord pada piano menggunakan metode fuzzy learning vector quantization
Abstrak: Seorang pemain piano pemula maupun autodidak umumnya belum melalui tahap latihan yang baik sehingga kemampuan untuk mengenali chord yang dimiliki masih kurang. Oleh karena itu, suatu sistem yang dapat mengenali chord untuk membantu proses pemahaman chord yang dimainkan dibutuhkan. Penelitian ini memodelkan chord yang terdiri atas 3 nada (triad) ke dalam beberapa kelas. Data yang digunakan dalam penelitian ini adalah 24 chord mayor dan minor. Data training dan data testing divariasikan dalam 4 model menggunakan 5-fold crossvalidation. Ekstraksi ciri akan dilakukan dengan metode Mel Frequency Cepstrum Coefficients, dan klasifikasi akan dilakukan dengan metode Fuzzy Learning Vector Quantization (FLVQ). Pemodelan FLVQ dilakukan dengan melakukan variasi pada learning rate serta koefisien fuzzyness. Penelitian ini telah berhasil membentuk model FLVQ dengan akurasi rata-rata 79.38% serta akurasi maksimum 100%. Akurasi maksimum dicapai dengan nilai learning rate α sebesar 0.05 dan koefisien fuzzyness β sebesar 0.05 menggunakan epoch sebanyak 20 pada FLVQ model 2.
Keyword: chord, FLVQ, MFCCs, modeling, note.