Judul: Penerapan bandpass filter dan Automatic Gain Control (AGC) pada data seismik laut (2D) di Laut Flores
Abstrak: Metode seismik sering digunakan untuk mengetahui geologi dasar laut dalam kegiatan eksplorasi laut. Penelitian ini bertujuan menghasilkan penampang seismik resolusi tinggi untuk memudahkan proses interpretasi data seismik, menganalisis jenis sedimen dasar laut dan menghitung nilai koefisien refleksi sedimen. Penelitian ini menggunakan data lintasan 5, 8, dan 10 di Laut Flores berekstensi SEG-Y. Metode pengolahan data yang digunakan yaitu bandpass filter dan Automatic Gain Control (AGC). Frekuensi bandpass filter didapat setelah dilakukan proses FFT. Hasil penelitian menunjukkan bahwa penampang seismik dengan frekuensi bandpass filter 45-60 Hz dan AGC 1000 menunjukan hasil yang paling jelas sehingga mudah diinterpretasikan. Koefisien refleksi sedimen stasiun 1 yaitu 0.2462 dan stasiun 4 bernilai 0.1936. Stasiun 5 dan 6 memiliki sedimen yang homogen berupa lumpur sehingga koefisien refleksinya bernilai 0. Ketebalan minimal yang dapat ditembus gelombang seismik dengan frekuensi 40 Hz adalah 9.2812 m sedangkan frekuensi 50 Hz adalah 8.6250 m. Echo yang terbentuk yaitu distinct echoes dengan tipe IB.
Keyword: Echo character, Automatic Gain Control, Bandpass filter, Seismic

Judul: Application of Bandpass Filter Method on Single Channel 2D Seismic data in Krakatoa Waters
Abstrak: Seismic menjadi salah satu metode yang menggunakan akustik kelautan untuk mengetahui struktur di bawah permukaan laut. Penampang seismik hasil akuisisi data biasanya terdapat noise yang merupakan gelombang atau sinyal yang tidak dikehendaki dan harus dibuang dari data utama. Untuk mengidentifikasi noise pada data seismic tersebut, dalam penelitian ini digunakan fungsi FFT atau Fast Fourier Transform. Penelitian ini bertujuan untuk memisahkan sinyal akustik objek dan noise pada data seismic dengan menggunakan fungsi FFT dan metode Bandpass Filter pada data Seismic Single Channel 2D di Perairan Krakatau. Akuisisi data seismic yang digunakan pada penelitian ini menggunakan peralatan single-channel high resolution seismic berupa EG&G Multi Electrode Sparker dan hidrofon 16 elemen merek EG&G sebagai receiver. Pengolahan data seismic dalam bentuk *segy pada penelitian ini menggunakan perangkat lunak Seisee dan Matlab. Frekuensi tepi optimal pada penelitian ini berkisar antara 7 Hz hingga 29 Hz, dan frekuensi 2400 Hz untuk tepi atas. Frekuensi cut-off optimal bergantung pada nilai frekuensi pada tiap Trace dengan nilai frekuensi cut-off bawah menggunakan frekuensi pada kisaran 200 Hz hingga 400 Hz dan nilai frekuensi cut-off atas menggunakan frekuensi 1500 Hz. Kata kunci: Bandpass Filter, FFT, Frekuensi, Noise, Seismic., Seismic is one method that uses marine acoustics to determine the structure below the sea surface. Seismic cross-sections resulting from data acquisition usually contain noise which is an unwanted wave or signal and must be removed from the main data. To identify noise in the Seismic data, this study used the FFT function or Fast Fourier Transform. This study aims to separate the object’s acoustic signal and noise in Seismic data by using the FFT function and Bandpass Filter method onSingle Channel 2D Seismic data in Krakatau waters. Seismic data acquisition used in this study used a single-channel high resolution Seismic form of EG&G Multi Electrode Sparker brand EG&G as receiver. Seismic data processing in the form of *segy in this study used Seisee and Matlab software. The optimal edge frequency in this study ranges from 7 Hz to 29 Hz, and the frequency is 2400 Hz for the top edge. The optimal cut-off frequency depends on the frequency value in each Trace with the lower cut-off frequency value using a frequency in the range of 200 Hz to 400 Hz and the upper cut-off frequency value using a frequency of 1500 Hz.
Keyword: Bandpass Filter, FFT, Frequency, Noise, Seismic

Judul: Peran nikotin dosis rendah terhadap profil glukosa darah dan insulin serta perubahan jaringan pankreas dan hati monyet ekor panjang (Macaca fascicularis) obes
Abstrak: Study of low dose nicotine intervention and its effect on blood and cellular level of obese cynomolgus monkeys has never been reported. The aims of this study were to evaluate the role of low dose nicotine on the profile of blood glucose, insulin level and cellular level alteration of pancreatic and hepatic tissue of obese cynomolgus monkey. Fourteen adult (aged 6–8 years) males cynomolgus monkeys grouped based on their Body Mass Index (BMI) into preobese (BMI=23.65–25.00) and obese (BMI ≥ 26.00) were used. Animals were grouped into four groups subsequently preobese with nicotine (pOb+), obese with nicotine (Ob+), preobese without nicotine (pOb-) and obese without nicotine (Ob-). Nicotine groups were fed with high fat diet mixed with nicotine dose 0.75 mg/kg body weight/day for three months and other groups without nicotine were fed monkey chow as control. Blood samples were collected every month for glucose analysis and insulin analysis at the end of study before necropsy was performed. Pancreatic and hepatic tissues were processed histologically and stained with hematoxylin-eosin and immunohistochemical method. The results showed that blood glucose significantly decreased (P<0.05) on the nicotine group, 28.37% (preobes) and 33.72% (obes) based on treatment duration compared to control group. Based on color intensity of granules cytoplasm of insulin producing cells or immunoreactive β-cells showed that non nicotine group were more reactive than those with nicotine group. As a conclusion, there was positive effect of low dose nicotine in maintaining the blood glucose level in normal range by stimulation of islet cells proliferation to maintain the production of insulin in the pancreatic islet. Nicotine low dose also affect to the hepatic parenchymal tissue that showed moderate level of hydrophic and fat degeneration, and necrosis. However, there were found hepatic cell regeneration.
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