Judul: Study on recirculation dryer of rough rice using Pneumatic Conveyor and blanded kerosene and jatropha curcas oil
Abstrak: Post harvest losses of rice in Indonesia was estimated to reach 20 % in which drying alone accounted for 2.3%. Most farmers in this country use the traditional direct sun drying, although cheap in cost it has the demerit of being dependent on weather conditions, susceptible to damage by rodent and easy being contaminated with dusts and foreign materials which can reduce the quality of products. Any delay in drying due to bad weather conditions will lead to excess in respiration and fungal growth, and sprouting due to re-wetting of products causing great losses in rice quality. The effect of global warming, due to accumulated green house gas (GHG) emissions in our atmosphere has created global climate change and uncertainty in weather conditions. Rainy days may occur during golden harvest making sun drying impossible and consequently drying should be delayed. The use of artificial dryer is facing another problem where fossil fuel as source of hot air generation is becoming scarce and high price. The aim of this study was to design a recirculation dryer of rough rice using pneumatic conveyor and blended fuel between kerosene and jatropha curcas oil to generate hot air for drying. This study comprises of five major components. First, is the study about the feasibility of using jatropha curcas oil as an energy source to produce drying air, second, experiments related to the influence of drying time and tempering durations on head rice yield (HRY) under non-flow static grain conditions, third, performance test of the proposed recirculation dryer, fourth computer simulation on recirculation dryer of rough rice using pneumatic conveyor and lastly, economic benefit of the proposed drying system.
Keyword: Recirculation dryer, Pneumatik conveyor, Head rice yield

Judul: Performance of Rotary Bed Dryer for Paddy in Several Configured Rotations
Abstrak: Mesin pengeringan tipe rotari tumpukan merupakan jenis pengeringan tipe mekanis untuk biji-bijian yang menggunakan prinsip putaran saat mengaduk bahan. Jenis biji-bijian yang digunakan pada penelitian ini adalah gabah. Penelitian ini bertujuan utuk mengetahui pengaruh perlakuan jeda dan lama waktu pengadukan dengan suhu tetap 45°C dalam meningkatkan keseragaman kadar air gabah menggunakan pengering tipe rotari tumpukan. Metode pengujian beda kadar air pada titik A dan B adalah pengukuran kadar air dengan prinsip gravimetri (oven) dan pengukuran keseragaman dengan prinsip t-test dengan P(t>T) dan faktor kesalahan α=0,05 pada dua sisi (two-tail). Hasil pengujian mesin pengering tipe rotari tumpukan menunjukkan bahwa seluruh perlakuan memberikan kadar air yang tidak berbeda (beda 0 %bb.) antar lapisan dalam dan luar pada akhir pengeringan. Konsumsi energi spesifik yang dibutuhkan sebesar 2684,7-4144,8 kJ/kg uap air sehingga menunjukkan bahwa konsumsi energi spesifik pengering tipe rotari tumpukan pada pengeringan gabah lebih kecil dibandingkan KES pengeringan biji-bijian konvensional (4260 kJ/kg uap air). Energi pengadukan hanya 2 % sedangkan energi pemanasan sebesar 89 % dari konsumsi energi total pengeringan dan biaya kebutuhan listrik. Hasil pengujian yang telah dilakukan menunjukkan adanya pengaruh besar proses pengadukan bahan yang dikeringkan untuk memperkecil nilai beda kadar air di lapisan luar dan lapisan dalam. Proses pengadukan tidak berpengaruh besar terhadap konsumsi energi spesifik dan biaya kebutuhan listrik., Rotary bed dryer is mechanical dryer for grains with rotary system for mixing grains. The grains that used in this study is paddy. The aim of this study is determine the impact of interval and duration of rotations with a fixed temperature in 45°C to increase the uniformity of the paddy with rotary bed dryer. Different moisture content test method for A and B point with gravimetric method (oven) and define uniformity using is used t-test statistic method in P(t>T) and failure factor (α) is 0,05 with two-tails test. The result of this rotary bed dryer show that all treatment was uniform (difference 0 %bb.) between inner and outer layer at the end of the drying process. The specific energy consumption required is 2684,7-4144,8 kJ/kg, it shows that the specific energy consumption of rotary bed dryer to reduce moisture content is smaller than the specific energy consumption of conventional grain drying (4260 kJ/kg). The mechanical energy was 2 % and the heated energy was 89 % of the total energy consumption and the cost of electricity. The results of the tests showed that the stirring process has to influence to decrease the different moisture content in outer later and inner layer. The stirring process does not effect the total energy consumption and the cost of electricity.
Keyword: drying, paddy, rotary bed dryer, uniformity

Judul: Pelabelan Super Vertex Magic
Abstrak: Super vertex magic labeling is labeling on graph with is a set of edges mapped into and is a set of vertices mapped into . It has a vertex magic labeling in which and represents the size and order of the graph respectively. This manuscript proves that paths, cyclics, and disjoint union of cyclics have a super vertex magic labeling. There are four theorems to be discussed. The first theorem proves that path is super vertex magic if and only if is odd and . The second theorem proves that cyclic is super vertex magic if and only if is odd. The third theorem proves that bijection function from an edge set onto of graph can be extended to a super vertex magic labeling if and only if the set amount of edge label that incidents with a vertex in the graph, consists of sequential integers as many as vertices in the graph. The fourth theorem proves that disjoint union of the cyclics consists of cyclics with each cyclic has vertices is super vertex magic if and only if and are odd.
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