Judul: Pemanfaatan dan strategi pengembangan perikanan demersal di Sibolga Provinsi Sumatera Utara
Abstrak: Demersal fish spend most of their life cycle in deeper sea column down to sea bottom. There were two main fishing gears that employed for demersal fishing in Sibolga namely trap and handline. The objectives of this study are to estimate utilization level of demersal fish resource, to identify the demersal fish size caught by traps and hand lines, to determine growth pattern of fish caught by traps and hand lines and to determine strategy for sustainable management of demersal fisheries in the study area. This study was conducted in Sibolga from December 2011 to May 2012 using survey method. Data were analyzed by means of surplus production model, length-weight relationships, and SWOT (Strengths, Weakness, Opportunities and Threats) to formulate strategies for sustainable demersal fisheries management in Sibolga. There were four dominant and most valuable economic demersal spesies caught in Sibolga: red snapper (Lutjanus malabaricus), white snapper (Lates calcarifer), sunu grouper (Plectropormus leopardus), and trevally (Caranx sexfasciatus). The result showed that catch level of red snapper had reached the optimum sustainable yield. Meanwhile the catch level of white snappers, grouper and trevally were still below their optimum sustainable yield. Traps and hand lines were considerably sustainable fishing gears due to the majority of catches have reached their length at first maturity. SWOT analysis was formulated for demersal fisheries development strategies in Sibolga. The analysis showed that the development should be focused on export markets, minimizing IUU fishing, laboratory quality assurance and enhancing cooperation among stakeholders.
Keyword: 

Judul: Development of traps for sustainable fishing at Sibolga
Abstrak: Rapid population growth in the world will has implication to the increasing demand for protein especially from fish. Traps is one of fishing gears to catch demersal or coral reef fish. Recently trap operation at coast of Western Sumatera has been restricted. The operation of trap is considered destructive for coral reef. The objectives of this research are to evaluate fishing operation technic of demersal fishing using basket traps, to measure technical performance of basket trap modification, to analysis potential fishing ground and catch of basket trap and to arrange development strategy of trap fisheries at coast of Western Sumatera. The research was conducted in coastal area of western Sumatera from March 2011 to February 2012. The methods applied in this research were experimental fishing and survey method. Analysis of data used descriptive analysis, the statictical analysis for significantly test, analysis hierarchy process and SWOT analysis. The result showed that the evaluation of fishing operation technic using basket trap need repair, especially from the way of landing and construction. There were 26 species found in four fishing grounds located around coast of western Sumatera. The 26 species were dominated by three families, for example Serranidae, Carangidae and Lutjanidae. Basket trap modification showed higher productivity compared to the fishers basket trap. The average catch of Sibolga fishermen was 57.66%, which was lower than the average catch of basket trap modification about 75.28%. Based on the factorial analysis, type of traps gave significantly influence to the catch of demersal fish. Analysis of hierarchy process showed that repairing technic operations of trap is the main priorities in improving the sustainable fishing at Sibolga. Development of capture fisheries activities must consider resources sustainability.
Keyword: 

Judul: Transisi Fasa Materi Hadronik ke Materi Kuark pada Inti Bintang Neutron.
Abstrak: Bintang neutron terdiri dari beberapa lapisan yang disusun oleh materi nuklir yang berbeda dengan kerapatan yang semakin tinggi ketika mendekati pusat bintang. Inti luar bintang neutron disusun oleh materi hadronik (nukleon, lepton, dan hyperon), sedangkan inti dalam bintang neutron disusun oleh kuark-kuark bebas (up, down, strange) yang saling berinteraksi. Tujuan penelitian ini adalah mempelajari bagaimana transisi dari inti luar ke inti dalam bintang neutron dengan menggunakan pendekatan RMF (Relativistic Mean Field) untuk materi hadronik dan CIDDM (Confined Isospin Density Dependent Mass) untuk materi kuark. Tekanan transisi diperoleh ketika potensial kimia barion materi hadronik dan materi kuark bernilai sama. Nilai tekanan transisi dengan parameter SU6-TM1 sekitar 87 MeV/fm3 dan diperoleh massa maksimum bintang neutron yaitu 1.92M dengan jari-jari sekitar 8.62 km. Nilai tekanan transisi dengan parameter SU6-G2 sekitar 53 MeV/fm3 dan massa maksimum bintang neutron yaitu 1.88M dengan jari-jari sekitar 8.16 km. Jenis transisi fasa adalah orde satu ditandai dengan diskontinuitas dalam kerapatan energi (adanya mixed phase). Parameter-parameter pada model nuklir yang digunakan menyebabkan perbedaan kekakuan persamaan keadaan (EOS) dari materi hadronik dan materi kuark sehingga nilai tekanan transisi dari fasa hadronik ke fasa kuark juga berbeda.
Keyword: bintang neutron, persamaan keadaan, transisi fasa