Judul: Optimasi Pengeringan Benih Jagung dengan Perlakuan Prapengeringan dan Suhu Udara Pengeringan
Abstrak: Drying is an important operation in corn seed processing. Long duration of seed drying can reduce seed viability. The high moisture content causes the initiation of seed germination and increase fungal attacks, thus it will loss seed viability. Long duration of seed drying also decreases production capacity and will increase production cost. One of the efforts to increase drying rate is increase air drying temperature. But, the high temperature in seed drying will give risk. It will give effect on chemical composition destruction so it could be decline seed viability. Maintaining seed viability could be done by using predrying treatment. Predrying was done by blowing air using blower machine and it applied before ear corn dried with heated air. Combination between predrying and air drying temperature were the effective treatment to increase drying rate and maintain corn seed viability. The objectives of the research were to increase corn seed drying efficency by develop design of drying system and combine between predrying treatment with air drying temperature to get maximum seed quality. This research was conducted at PT BISI International, Tbk. on June till October 2012. This research consisted of three phases, 1. Drying system design, 2. Corn seed drying optimization, and 3. Economic analysis. The first research consisted of two phases, 1. Mini box dryer assembling, and 2. Mini box dryer testing. Corn seed drying optimization consisted of periods of predrying (0, 12, 24, and 36 hours) and temperature level factor (40, 45, 50, and 55 °C), used randomized complete block design with three replications. Physical and physiological quality were analyzed to find treatment which produced good seeds. Economic analysis were used to find treatment which give highest of B/C Ratio. The result showed that predrying during 36 hours on temperature setting 50 °C was the optimum treatment for corn seed drying, because it had good germination and had highest B/C Ratio.
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Judul: Strategi Pengendalian Pengeringan Jagung Pipil dengan Kadar Air Tinggi yang memanfaatkan Udara Lingkungan
Abstrak: A bed dryer model has been designed and constructed to study control stategy of ambient drying for high moisture content shelled corn. The control strategy developed in this research was based on the diference of moisture content and the moisture content equivalent of ambient air. The action of the control system was the rotational speed of fan regularity to control the air flow rate. The result showed that with at initial moisture content of corn 20% w.b to the final moisture content of 13.61% w.b. drying were accomplided in 69.5 hours and fan turn on for 20.5 hours with the condition rated highest temperature recorded during the drying process is 37.5oC, and thelowest temperature was 28.5C. Average temperature was 29.15oC, and also was obtained that the highest environtmental RH recorded was 94.8% and the lowest RH was 52.4% RH environmental so that the average was 82.83%, and consumed electrical energy around 4.25 kWh or 15.3 Megajoules. From that equation, assumed energy consumption per kilograms of water evaporated was 4.37 MJ. From the above result the controller system in this dryer is working properly as per design.
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Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology