Judul: Pemanfaatan Frekuensi Bunyi untuk Menduga Kadar Air dan Vigor Benih Jagung (Zea mays L.)
Abstrak: Seed lots in different condition were needed as material of this sound detection research. The goal of this research is learning about utilization of sound frequency to expect moisture content and vigour of the corn seed. This research was conducted at Seed Science and Technology Laboratory, Bogor Agricultural University and Spectroschopy Laboratory, Bogor Agricultural University from February 2013 to June 2013. The experiment was arranged in complete randomized design with two factors and three replications. This research divided in two experiments, (1) correlation between variety and seed moisture content and (2) correlation between variety and seed vigour about its frequencies output. Seed size definited by its 1 000 granule mass, Srikandi Putih variety is used for big size, Bisma is used for medium size and SD-III is used for small size. Several moisture content levels are got by closed moisturizing process. Seed lots with three different vigor levels are got by physical accelerating method, used oven in 40-45 °C and high moisture condition. After gave the preface treatment, the seed lots got the sound detection testing. The result showed in the first experiment, variety could give effect to the frequency output. The second experiment gave result that variety, vigour level and interaction of both didn’t give effect to the frequency output. Sound frequency cannot be used to expect moisture content and vigour of corn seed, but sound frequency can be used as variety marker.
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Judul: Pemanfaatan Alat Deteksi Bunyi untuk Menduga Kadar Air dan Viabilitas Benih Kedelai (Glycine max L. Merrill)
Abstrak: Quick detection of moisture content and seed viability is very important in seed technology. The use of sound frequency that produced by seed if that seed reflected with another material is one method that haven’t yet researched. The purpose of this research is sound detection to determine moisture content and viability of soybean seeds by looking the sound waves frequency produced. This research consisted of two experiments, the first experiment the effect size of seed and moisture content of the sound frequency. The second experiment the effect size of seed and viability of the frequency. This research was arranged in the randomized completely design was used with twofactorsis size of seed and moisture content (first experiment) and size of seed and viability (second experiment). The results showed that sound detection can used to estimate the moisture content of seed but can’t used to estimate viability of seed. Results showed that sound detection devices can be used to estimate the water content of seeds without seeing the size of the seed, but can’t used to estimate viability of seed. The first experiment had a negative correlation between the frequency and moisture content has a value of correlation (r) 0.95 approach 1 (≈ 1), it meansthe higher water content, the frequencies lower sound produced.
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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