Judul: Propagasi suara di luar dan dalam ruangan pada berbagai suhu dan jenis permukaan
Abstrak: Propagasi suara dapat terjadi di dalam dan luar ruangan. Tentu saja pola propagasi suara yang terjadi di dalam dan luar ruangan berbeda akibat adanya komponen-komponen berbeda di dalamnya. Diantaranya adalah kondisi meteorologi seperti variasi suhu dan angin, penyerapan suara oleh atmosfer, kontur dan jenis permukaan, serta penghalang seperti bangunan dan tanaman. Berdasarkan penjelasan tersebut, terdapat komponen jenis permukaan dan variasi suhu udara yang dapat mempengaruhi pola propagasi suara. Maka dari itu, dilakukan penelitian yang melibatkan kedua komponen itu. Adapun tujuan dari penelitian ini adalah menentukan keterkaitan sebaran kebisingan akibat jenis permukaan dan perbedaan suhu udara dan mendeskripsikan sebaran kebisingan pada skala model (dalam ruangan) dan pada kondisi nyata (luar ruangan) dengan perbedaan suhu udara dan jenis permukaan yang ada. Berdasarkan tujuan penelitian ini, parameter yang digunakan adalah suhu udara dan jenis permukaan. Adapun metode yang digunakan dalma penelitian ini adalah metode Inverse Square Law. Selain itu juga digunakan penyaringan frekuensi 1/3 oktaf. Berdasarkan pengukuran yang dilakukan, didapat hasil bahwa faktor suhu udara ternyata tidak semuanya berpengaruh nyata terhadap tingkat tekanan suara di luar ruangan. Hanya pada beberapa frekuensi, yaitu pada frekuensi 63, 80, 100, 160, 315, 630, 800, 1000 (Hz). Akan tetapi, untuk faktor jenis permukaan, semua frekuensi yang telah diklasifikasikan berpengaruh nyata terhadap tingkat tekanan suara. Maka dengan kata lain, tingkat tekanan suara yang diterima pada kondisi luar ruangan bergantung pada jenis permukaan tempat dimana sumber bising itu berada. Lain halnya hasil yang didapat dari pengukuran pada kondisi dalam ruangan. Setelah pengukuran didapatkan hasil bahwa faktor suhu udara berpengaruh nyata terhadap tingkat suara pada semua frekuensi hasil klasifikasi.
Keyword: Propagation of sound, Air temperature, Surface type, Frequency, Sound pressure level, Bogor Agricultural University, Institut Pertanian Bogor, IPB

Judul: Propagasi Suara di Luar dan Dalam Ruangan pada Berbagai Suhu dan Jenis Permukaan
Abstrak: Sound propagation can occur in the indoor and outdoor. The sound propagation patterns that occurring inside and outside the room is different because of different components in it. Among them are variations of meteorological conditions such as temperature and wind, the sound absorption by the topography, climate and type of surface, and obstructions such as buildings and crops. Based on these explanations, there are components of the type of surface and air temperature variations that can affect the sound propagation patterns. So, the research which involving both components was done. The purpose of this study is to determine the relevance of the distribution of votes because of differences in surface temperature and air and noise in the model describes the distribution of scale (indoor) and the actual conditions (outdoor) with differences in air temperature and type of existing surface. Based on the purpose of this study, the parameters used are air temperature and type of surface. The method used in this research is Inverse Square Law. Beside that, it is also the filtering frequency was done using 1/3 octave. Based on the measurements, the result is not all the factors of air temperature significantly affects the sound pressure level outside the room. Only in a few frequencies, that is at a frequency of 63, 80, 100, 160, 315, 630, 800, 1000 (Hz). However, for all type of surfaces factors in all the frequency that have been classified was significantly affects the sound pressure level. So in other words, the sound pressure level received at the outdoor conditions depending on the type of surface where the sound source is located. Another case of the measurement results obtained in the room. After the measurement the result showed that the factor temperature significantly affect the sound level at all frequencies results classification.
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Judul: Peptides Hydrolysate Derived from Collagen of Snakehead Murrel (Channa striata) Skin Demonstrate Anti-oxidant and Anti-cholesterol Activities.
Abstrak: Anti-cholesterol and anti-oxidant play crucial role to combat cardiovascular disease (CVD) related to formation of arterial plagues from oxidation of cholesterol. In the past decades, research on bioactive peptides demonstrating anti-cholesterol and anti-oxidant activities have been reported as the alternative drugs. In this study, acid soluble collagen was extracted from the skin of snakehead murrel and employed to induce production of collagenase by Bacillus licheniformis F11.4. The collagenases secreted were in turn purified through AKTA Purifier (ion exchange, DEAE column) and used to produce peptides hydrolysate. The purified enzymes were grouped in two distinct collagenase fractions, designated as fraction D and F. Peptides hydrolysate produced by the fraction D was found to demonstrate HMG-CoA inhibitor activity comparable to pravastatin and limited anti-oxidant activity. Meanwhile, peptides hydrolysate generated using the fraction F demonstrated anti-oxidant activity comparable to BHT (2mM), vitamin C (2mM) and vitamin E (2mM), but limited HMG-CoA activity. Combination of the fraction D and F resulted in substantial HMG-CoA inhibition and anti-oxidant activities.
Keyword: Anti-cholesterol, anti-oxidant, bioactive peptide, collagen, collagenase, snakehead murrel