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.
Keyword: 

Judul: Analisis Propagasi Akustik Bawah Air di Selat Sunda
Abstrak: Selat Sunda terletak di antara Pulau Jawa dan Sumatera yang menjadi salah satu Alur Laut Kepulauan Indonesia (ALKI 1). Penelitian ini bertujuan untuk menganalisis propagasi akustik bawah air di perairan Selat Sunda bagian selatan pada Musim Peralihan 1 tahun 2020. Data diakses dari laman marine.copernicus.eu berupa data arus, suhu, salinitas, dan kedalaman di 4 stasiun yang berbeda dan diproses menjadi data lingkungan. Kecepatan suara akan diproses menggunakan formula Mackenzie menggunakan data suhu, salinitas, dan kedalaman. Model bellhop merupakan suatu metode beam tracing yang ditransmisikan melalui medium air laut menggunakan data lingkungan. Hasil simulasi menunjukkan adanya bermacam-macam propagasi suara yang terjadi pada setiap stasiun yang diamati akibat adanya faktor kedalaman transduser dan kedalaman perairan. Sudut half bim 5° dan 10° lebih merambat di dasar perairan karena gradien kecepatan suara negatif sedangkan pada pancaran half bim 15° menunjukkan adanya pancaran di permukaan dan dasar perairan. Semakin besar sudut beam maka jarak pancaran suara akan semakin menjauh, begitu juga sebaliknya., Sunda Strait located between Java and Sumatera and being one Indonesian Archipelagic Sea Lanes part. This study aimed to analyzing underwater acoustic propagation in the southern Sunda Strait waters during Transition Season 1 of 2020. Data was taken from marine.copernicus.eu website which were sea current, temperature, salinity, and depth in 4 different stations which will be processed into environment data. Speed of sound will be processed with MacKenzie formula using temperature, salinity, and depth data. Bellhop modelling is a beam tracing method which transmitted through sea water medium using environment data. At the study area found the presence of thermocline, halocline, and mixed layer. The simulation shows that there are various kinds of sound propagation occurred at each observed stations due to the transducer’s depth and water depth factor. At 5° and 10° half beam angle propagates more at the bottom because of negative speed of sound gradien whereas at 15° shows there is a propagation at the bottom and surface of waters. Greater the beam angle, the distance of the sound propagation will be further away and vice versa.
Keyword: bim, kecepatan suara, kedalaman, suhu, salinitas

Judul: Embriogenesis ikan buta (Astyanax fasciatus)
Abstrak: Ikan buta Astyanax fasciatus adalah spesies ikan unik dari famili Characidae yang menempati perairan dalam gua di Wilayah La Cueva Chica-San Luis Potasi-Mexico. Ikan ini memiliki mata yang tereduksi (Blind Cavefish) dan warna kulit merah muda, pucat serta mengkilap.
Keyword: