Judul: Penggunaan Naungan yang Berbeda pada Pendederan Benih Ikan Lele di Bak Terpal
Abstrak: Catfish fry rearing is usually done in the pond of land in open space. Fish fry mortality because of high fluctuations in water quality to be very high, especially in the rainy season. Shade usage on fish rearing was expected to reduce the changes of water quality parameters from heat and rain. This research uses terpaulin container with a (300X400X50) cm dimension, each were given shades from different materials as given, transparent plastic (treatment 1), shading net (treatment 2), and dark plastic (treatment 3), while control container were not given any shade. This research resulted in a very low survival rate 13.82±8,77% on treatment 1, 1.08±1,87% on treatment 2, 0.12±0,2% on treatment 3, and 13.65±4,17% on control. Highest weight daily growth rate were acquired by treatment 1, namely 1,094±0,0186%, and the lowest were in control fish 1,079±0,0096%. Highest increase the absolute length were acquired by treatment 1, namely 3,53±0,602 cm, and the lowest were in control fish 2,79±0,185 cm. Based on variance analysis, the usage of shades on catfish rearing did not gave a significant effect on increase the absolute length and weight daily growth rate (p>0,05), but it affects the survival rate significantly (p<0,05). The usage of transparent plastic is suggested for catfish fry rearing in tarpaulin container.
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Judul: Performance of Production and Bussiness on Catfish (Clarias sp.) Grow-out in Different Container Forms at Trio Raja Mandiri Farm, Bogor
Abstrak: Ikan lele banyak digemari masyarakat karena harga terjangkau dan memiliki kandungan protein yang tinggi. Permintaan pasar terhadap ikan lele terus meningkat sehingga memacu pembudidaya ikan lele guna memenuhi permintaan pasar tersebut. Bentuk wadah yang banyak digunakan dalam budidaya ikan lele, yaitu bulat dan persegi. Penggunaan wadah terpal dengan bentuk bulat dan persegi memiliki kelebihan dan kekurangannya masing-masing. Hasil budidaya nantinya akan mempengaruhi produktivitas dan nilai keuntungan yang didapatkan. Penelitian ini bertujuan menganalisis kinerja produksi dan kinerja usaha pembesaran ikan lele pada bentuk wadah yang berbeda, yaitu bulat dan persegi panjang. Penelitian ini menggunakan metode studi kasus dengan melakukan pengamatan data secara langsung selama budidaya, wawancara, serta pengumpulan data yang berkaitan dengan usaha budidaya. Hasil penelitian menunjukkan bahwa kinerja produksi pada pembesaran ikan lele menghasilkan produktivitas rata-rata pada wadah bulat sebesar 19,76±1,35 kg/m2 dan pada pada wadah persegi panjang sebesar 9,57±1,85 kg/m2. Kinerja usaha yang didapatkan pada wadah A dengan nilai payback period (PP) 0,73 tahun dan revenue cost ratio (R/C) 1,35, untuk wadah B didapatkan nilai PP 1,45 tahun dan R/C 1,12. Kinerja produksi dan kinerja usaha pembesaran ikan lele dengan penggunaan wadah bulat didapatkan nilai lebih tinggi daripada wadah persegi panjang., Catfish is highly favored by the community due to its affordable price and high protein content. The market demand for catfish continues to increase, driving catfish farmers to meet the market demand. The commonly used forms of containers in catfish farming are round and rectangular. The use of tarpaulin containers in round and square shapes has their respective advantages and disadvantages. The cultivation results will ultimately affect the productivity and profitability. This research aims to analyze the production performance and business performance of catfish farming in different container shapes, namely round and rectangular. This study employs a case study method, which involves observation, interviews, and direct participation in the activities to collect data. The research findings indicate that the production performance of catfish farming yields an average productivity of 19,76±1,35 kg/m2 in round containers and an average productivity of 9,57±1,85 kg/m2 in rectangular containers. The business performance obtained in container A shows a PP (payback period) value of 0,73 years and an R/C (return on capital) ratio of 1,35, while in container B, the PP value is 1,45 years and the R/C ratio is 1,12. The production performance and business performance in catfish farming using round containers yield higher values compared to rectangular containers.
Keyword: catfish, business performance, production performance, round container, square container

Judul: Kruskal Coordinates in 4+1 Dimensional Schwarzschild  Spacetime Geometry
Abstrak: Koordinat Kruskal adalah hasil ekstensi maksimal dari koordinatSchwarzschild yang menimbulkan interpretasi baru tentang keberadaan wormhole. Secara teori, wormhole adalah struktur yang menghubungkan dua titik berbeda dalam ruangwaktu. Namun, ukuran wormhole terlalu kecil untuk dapat dilalui dan tidak stabil sehingga mudah runtuh. Penelitian ini bertujuan mendapatkan solusi koordinat Kruskal untuk geometri Scwarzschild pada dimensi yang lebih tinggi yang dapat berguna untuk menganalisis kestabilan wormhole. Penelitian ini dilakukan melalui penambahan dimensi ruang dari 3+1 dimensi menjadi 4+1 dimensi untuk mendapatkan geometri Schwarzschild, koordinat Eddington-Finkelstein, dan koordinat Kruskal dengan memanfaatkan gerak radial foton. Hasil akhirnya, solusi geometri ruangwaktu Schwarzschild dalam koordinat Kruskal dapat dibentuk dan diilustrasikan dalam diagram Kruskal. Diagram tersebut menunjukan sebuah black hole, white hole, dan dua alam semesta yang dihubungkan oleh wormhole., The Kruskal coordinates are the maximal extension of the Schwarzschild coordinates which give rise to new interpretations of the existence of wormholes. In theory, a wormhole is a structure that connects two different points in spacetime. However, the size of the wormhole is too small to pass through and is unstable so that it collapses easily. This study aims to obtain Kruskal coordinate solutions for the Scwarzschild geometry in higher dimensions which can be useful for analyzing wormhole stability. This research was carried out by adding space from 3+1 dimensions to 4+1 dimensions to obtain Schwarzschild geometry, Eddington Finkelstein coordinates, and Kruskal coordinates by utilizing the radial motion of photons. The final result, the solution of the Schwarzschild spacetime geometry in Kruskal coordinates can be formed and illustrated in a Kruskal diagram. The diagram shows a black hole, a white hole, and the two universes connected by a wormhole.
Keyword: Schwarzschild geometry, Eddington-Finkelstein coordinates, Kruskal coordinates, radial motion of photons, wormhole