Judul: Pemetaan shadow zone akustik dengan metode parabolic equation di wilayah perairan Selat Lombok
Abstrak: Dalam melakukan perambatan di dalam air, gelombang suara dipengaruhi oleh karakteristik oseanografi seperti salinitas, suhu, dan tekanan dimana ketiga hal ini mempengaruhi kecepatan gelombang suara dalam air. Saat melakukan perambatan, gelombang suara membentuk suatu pola tertentu yang dapat dipengaruhi oleh frekuensi, posisi sumber suara dan posisi penerima. Dalam melakukan penyusupan, kapal selam kerap kali menggunakan shadow zone yang merupakan zona dimana hampir tidak terjadi perambatan gelombang suara, sehingga kapal selam tersebut dapat terhindar dari SONAR (Sound Navigation and Ranging) pihak lawan.
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Judul: Pemetaan Shadow Zone Akustik dengan Metode Parabolic Equation di Wilayah Perairan Selat Bali
Abstrak: Shadow Zone adalah suatu wilayah dimana gelombang bunyi tidak dapat menembus suatu kolom perairan akibat pembelokkan. Penelitian ini bertujuan memetakan shadow zone berdasarkan parameter oseanografi di Perairan Selat Bali. Data yang digunakan adalah suhu, salinitas, dan kedalaman selama 31 hari pada Musim Timur (Juli) di Selat Bali pada dua stasiun yang merupakan hasil pemodelan numerik yang diunduh dari situs https://marine.copernicus.eu/. Simulasi shadow zone menggunakan metode parabolic equation dengan batasan parameter tertentu. Profil vertikal suhu menunjukkan bahwa, semakin dalam perairan, suhu akan semakin berkurang, sedangkan salinitas berlaku sebaliknya. Kecepatan suara dipengaruhi oleh parameter suhu dan salinitas. Pada letak tranduser 25 m, medium yang tidak terkena pancaran lebih sempit dibandingkan dengan letak tranduser 110 m sehingga area shadow zone dengan posisi tranduser 110 m memiliki area lebih luas. Shadow zone pada bagian Utara Selat Bali efektif dideteksi menggunakan frekuensi 100 Hz, sedangkan pada bagian Selatan Selat Bali efektif dideteksi pada frekuensi 38 Hz, dengan posisi tranduser masing – masing yang digunakan pada kedalaman adalah 25 dan 110 m. Kata kunci : Kecepatan suara, Parabolic Equation, Selat Bali, Shadow zone, Acoustic Shadow Zone Mapping Using Parabolic Equation in the Bali Strait Waters. Supervised by SRI PUJIYATI and AYI RAHMAT. Shadow Zone is an area where sound waves cannot penetrate a water column due to deflection. This study aims to map the shadow zone based on oceanographic parameters in the Bali Strait. The data used are temperature, salinity, and depth for 31 days in the East Season (July) in the Bali Strait at two stations which are the results of numerical modeling that downloaded from the website https://marine.copernicus.eu/. shadow zone simulation uses the parabolic equation metode with certain parameter limits. The vertical temperature profile shows that the deeper the water is, the lower the temperature will be, whereas salinity is the opposite. The sound velocity is affected by the parameters of temperature and salinity. At the location of the 25 m transducers, the medium that is not exposed to the beam is narrower than the location of the 110 m transducers so that the shadow zone with a 110 m transducer position has a wider area. Shadow zone area in the northern Bali Strait is effectively detected using a frequency of 100 Hz, while in the southern part of the Bali Strait it is effectively detected at a frequency of 38 Hz, with the respective transducer positions used at a depth of 25 and 110 m. Keywords: Bali Strait, Parabolic Equation, Shadow zone, Sound Velocity
Keyword: Bali Strait, Parabolic Equation, Shadow zone, Sound Velocity

Judul: Biological Characteristics of Jatropha curcas Trimonoecious
Abstrak: Physic nut (Jatropha curcas L.) is an original plant from tropical America belonging to the family of Euphorbiaceae and an annual plant of monoecious. Commonly J.curcas have male and female flowers on the same plant. There are currently some J. curcas which have hermaphrodite flowers from monoecious plants, but very rarely. J. curcas with hermaphrodite flowers are classified as andromonoecious type (having hermaphrodite and male in the same plant) and trimonoecious type (having male, female, and hermaphrodite flowers in the plant). Trimonoecious plants with hermaphrodite flowers were tend to perform self-pollination (geitonogamy) and produce a homogenous and high-productivity in next generation. J. curcas plants is difficult in differentiating between monoecious and trimonoecious plants when it seedling, and this is a limiting factor to know development of trimonoecious J. curcas. Trimonoecious J.curcas can be identified after six months of planting, and when it have started flowering. Therefore, the trimonoecious J. curcas biological characteristics needs to be an observation. The trimonoecious trait in J. curcas plants can be identified through several analyses, i.e. the analysis of agronomical characteristics, the chromosomes analysis, the isozyme analysis, and the analysis of pollen viability. The study was conducted in December 2011 - February 2013. The experiments were conducted using the Randomized Complete Block Design for one factor, the J. curcas genotype with 5 replicates. Each unit of the experiment consisted of 5 plants. Aagronomics characteristic analyses were conducted using analysis of variance (ANOVA) followed by the Duncan Multiple Range Test (DMRT) at 5% level. The classification of heritability and Genetic Variation Coefficient (GVC) criteria and relative Phenotypic Variation Coefficient (PVC). The analysis of genetic distance clustering was done using the Minitab 1.5 program clustering method. J. curcas stem trimonoecious characters is the primary branches angle, stem diameter, number of primary and secondary branches have a higher size than monoecious plants. Diameter and thickness fruit flesh origins from monoecious plants larger than fruit from plants trimonoecious. Characteristics of the trimonoecious plants in this study were almost the same with their mother plant. Number chromosomes number of J. curcas plant genotypes have 2n = 22 chromosomes The average length of the trimonoecious plant’s chromosome was longer than the average for monoecious plants. The length of chromosomes can differ among one family, even though the numbers of the chromosomes are similar. Isozymes peroxidase (Rf 0.83) and esterase (Rf 0.20) could be used as markers to differentiate between trimonoecious and monoecious plants. Male flower pollen viability of plant origin trimonoecious have a slower rate of decrease than male flowers monoecious plants. The dendrogram from the cluster analysis results could differentiate between trimonoecious and monoecious plants with a variation coefficient of 27.25.
Keyword: Esterase, peroxidase, pollen viability, trimonoecious