Judul: Pengembangan biosensor glukosa menggunakan metode screen printing untuk deteksi kadar glukosa dalam darah
Abstrak: Telah dilakukan pengembangan disposable biosensor (biosensor sekali pakai) untuk deteksi glukosa dalam darah menggunakan metode screen printing. Biosensor dibuat dengan sistem tiga elektroda yaitu elektroda kerja, elektroda pendukung, dan elektroda pembanding. Uji EIS (Electrochemical Impedance Spectroscopy) dilakukan dengan alat LCR meter tipe HIOKI 3522-50 LCR HiTESTER untuk mengetahui konduktivitas dan impedansi elektroda kerja pada frekuensi antara 42 Hz sampai 100 kHz. Proses immobilisasi enzim dilakukan dengan metode drop coating pada permukaan elektroda kerja menggunakan mediator 1,1’-Dimethylferrocene dimana enzim yang digunakan adalah glukosa oksidase (GOD). Uji sensitivitas dilakukan dengan tekhnik cyclic voltammetry dengan memvariasikan konsentrasi glukosa yakni 25 mg/dl, 50 mg/dl, 75 mg/dl, 100 mg/dl, 125 mg/dl, 150 mg/dl, dan 200 mg/dl. Stabilitas biosensor diuji dengan memvariasikan lama penyimpanan strip biosensor yang sudah diimmobilisasi selama 1 minggu dan 2 minggu dengan variasi konsentrasi glukosa 50 mg/dl, 100 mg/dl, dan 150 mg/dl. Hasil uji EIS menunjukkan bahwa konduktivitas elektroda kerja biosensor sebesar 7.8 x 10-4 Siemens.m-1 dan memiliki impedansi yang kecil dibandingkan dengan penelitian sebelumnya.
Keyword: Cyclic voltammetry, Reaksi analit-receptor, Penicillium notatum

Judul: Pengembangan Biosensor dengan Menggunakan Teknik Screen Printing untuk Deteksi Kadar Kolesterol
Abstrak: Telah dilakukan pengembangan biosensor kolesterol dengan metode screen printing. Desain elektroda dengan konfigurasi tiga elektroda kemudian dikarakterisasi konduktifitas AC dan impedansi AC elektroda kerja dengan variasi frekuensi 42 Hz sampai dengan 100 kHz. Proses imobilisasi enzim kolesterol oksidase dengan mediator 1,1’-Dimethylferrocene dilakukan pada suhu ruangan dengan cara drop coating pada permukaan elektroda kerja. Setelah itu pengujian strip biosensor kolesterol dilakukan dengan teknik cyclic voltammetry. Sampel kolesterol yang digunakan 100 mg/dl, 125 mg/dl, 150 mg/dl, 175 mg/dl, 200 mg/dl, 250 mg/dl, 300 mg/dl. Pengujian stabilitas strip biosensor dilakukan dengan menyimpan strip biosensor yang telah diimobilisasi enzim ke dalam refrigerator selama delapan hari dengan suhu -150C. Hasil penelitian didapat konduktifitas AC dan impedansi AC elektroda kerja sebesar 4,8 x 10-4 Siemens.m-1 dan 9,039 KΩ. Sensitifitas biosensor kolesterol diperoleh sebesar 3x10-7 μA.mg-1dl dan sensitifitas biosensor kolesterol hari ke-8 menurun 97% dari nilai sensitifitas hari ke-0 menjadi 9x10-9μA.mg-1dl sehingga stabilitas penyimpanan strip biosensor sangat tidak stabil dan memuaskan. Akurabilitas strip biosensor kolesterol diperoleh sangat rendah.
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Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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