Judul: Bioakustik Stridulatory Gerak Ikan Guppy (Poecilia reticulata) Saat Proses Aklimatisasi Kadar Garam
Abstrak: Bioacoustic learn the sound frequency range of fish, the intensity of the sound amplitude, sound fluctuations, and shape the sound patterns of the fish. Acclimatization is a physiological adjustment efforts or adaptation of an organism to a new environment that will be entered, this study looked at the process of acclimation salinity on Guppy fish (Poecilia reticulata). This analyze its voice of Guppy (Poecilia reticulata) study process using the bioacoustic method during acclimatization, and looking at the behaviour of Guppy fish by doing addition salts of 2 g/mol to salinity of 30% . Initial value of the highest intensity at which the fish Guppy after the addition of salt at day 3 and 7 have a higher intensity, with an average intensity that is at -44 dB in the time range 40-50 seconds. This study shows that Guppy fish can survive at a salinity of 30 ‰ with a value of -48 dB intensity and frequency from 0 until 19.6 kHz
Keyword: Study Bioacoustic, Salinity, Sound characteristic, salt levels, The guppy (Poecilia reticulata)

Judul: Karakteristik Bioakustik dan Tingkah Laku Ikan Mujair (Oreochromis mossambicus) terhadap Perubahan Salinitas
Abstrak: Swim bladder of fish body part that serves to amplify the voice and breathing apparatus in fish. Tilapia fish is one type of vertebrate fish that have swim bladder that is used as a resonance chamber that produces sound to communicate. Tilapia fish is one type of vertebrate fish that have swim bladder that is used as a resonance chamber that produces sound to communicate. Physiologically, fish behavior can be shown with the character of the sound produced. Bioakustik research can analyze the behavior and characteristics of the sound produced bubbles tilapia fish swimming in waters with different salinity. The study was conducted in June 2013 at the Laboratory of Acoustics and Marine Instrumentation, Bogor Agricultural University with stage includes the preparation of the aquarium , the selection of fish , adding salt , visual observations in the aquarium , visual observations in open water , voice recording and data analysis . The results showed on day 1 to day 6, the frequency and frequency operculum tilapia fish mouth opening increased. Day 7 to day 15, the frequency and the frequency of mouth opening operculum tilapia fish slowed. The intensity of the sound produced tilapia fish is influenced by the behavior due to the effect of the contraction of the muscles of the swim bladder in fish tilapia.
Keyword: behavior, sound, tilapia fish, swim bladder, bioacoustics

Judul: Solusi Geometri Schwarzschild untuk Dimensi 4+1 dengan Invarian Rotasi Isotropik
Abstrak: Metrik Schwarzschild merupakan solusi eksak pertama dari persamaan medan Einstein dengan mangasumsikan metrik statik dan simetris. Metrik Schwarzschild yang ditemukan oleh Karl Schwarzschild masih dalam dimensi 3+1, namun seiring dengan teori-teori terbaru yang menunjukkan bahwa alam semesta tidak hanya di dimensi 3+1. Maka melalui penambahan dimensi, tujuan penelitian ini memperoleh solusi pada geometri Schwarzschild untuk dimensi 4+1 dengan memodifikasi koordinat bola yang invarian rotasi isotropik dan melalui penurunan rumus seperti koordinat bola, simbol Christoffel, dan tensor Ricci. Selain mendapatkan solusi ini, metrik Schwarzschild dimensi 4+1 dapat digunakan sebagai metrik dasar untuk memperoleh solusi blackhole dan wormhole pada dimensi 4+1. Hasil akhirnya, dengan memanfaatkan modifikasi koordinat bola, metrik Schwarzschild dapat dibentuk sehingga diperoleh solusi geometri Schwarzschild untuk dimensi 4+1.
Keyword: metrik Schwarzschild, persamaan medan Einstein, modifikasi koordinat bola, penambahan dimensi, invarian rotasi isotropik