Judul: Studi Aplikasi Knapsack Sprayer, Knapsack Power Sprayer, dan Boom Sprayer di PT Laju Perdana Indah, Palembang, Sumatera Selatan
Abstrak: The purpose of the research was to determine effectiveness, herbiciding cost, and performance of weed control using knapsack sprayer (KS), knapsack power sprayer (KPS), and boom sprayer (BS) in dry land sugar cane area at Laju Perdana Indah Company, Palembang, South Sumatera. Three kind of sprayers were applied for herbiciding on March 2012. Knapsack sprayer and knapsack power sprayer were manually operated by operator, were as boom sprayer was mechanically operated by 75 hp (56 kW) tractor. Active substances were use for herbiciding are 2,4 D-amina, ametryn, paraquat, sticker, glyphosate, and diuron with dosage range of (0.5-2.5) litre/ha. Research showed that herbiciding effectiveness and efficiency using three kind of sprayers gave different results. KPS was more effective than KS because percentage killed weeds after herbiciding using KPS is 77.0%, however using KS is (53.6-59.5)%. Average operational speed when at herbiciding using KS, KPS, and BS were 0.56 m/sec, 0.59 m/sec, and 2.00 m/sec respectively, so that it gave big influence for effective field capacity were (0.10-0.11) ha/hour, 0.20 ha/hour, and 2.66 ha/hour respectively. Herbicide Solutions discharge using KS, KPS, and BS were (60.69-65.40) litre/hour, 85.30 litre/hour, and 1206.00 litre/hour respectively, so that it gave result for throwput capacity are (588.64-617.01) litre/ha, 418.94 litre/ha, and 453.87 litre/ha. Difference in kind of sprayers would gave different performance. Herbiciding inefficiency using KS and KPS were (47.2- 54.3)% and 4.7%, so that it dissipation (188.64-217.01) litre/ha and 18.94 litre/ha, therefore using BS was most economically because it could economize hebicide solutions consumption of 24.4% or 146.13 litre/ha. Herbiciding cost using KS, KPS, and BS were Rp (294,925.75-303,230.95)/ha, Rp 317,575.82/ha, Rp 127,712.46/ha respectively. Herbiciding time using KS, KPS, and BS were (9- 10.17) hour/ha, 4.91 hour/ha, and 0.38 hour/ha respectively. The herbiciding effectiveness on the field for KS was (82.6-82.8)% with killed weeds percentage was (53.6-59.5)% and KPS was 93.7% with killed weeds percentage was 77%. KPS was more effective in hebiciding than KS and BS was the most efficient sprayer for herbiciding in dry land sugar cane area.
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Judul: Performance of  Knapsack Sprayer, Knapsack Power Sprayer, and Mist Blower in Pesticides Application on Corn Plants
Abstrak: Jenis sprayer tipe gendong yang dijual di pasaran sangat beragam dan masing-masing jenis sprayer memiliki keunikannya tersendiri. Tiga jenis sprayer tipe gendong yang umum digunakan, yaitu knapsack sprayer, knapsack power sprayer, dan mist blower, yang perlu dievaluasi kinerjanya penyemprotan pestisida pada tanaman jagung. Penelitian bertujuan untuk menentukan dan membandingkan kinerja knapsack sprayer, knapsack power sprayer, dan mist blower dalam penyemprotan pestisida pada tanaman jagung. Pengukuran lebar penyemprotan efektif, debit, dan diameter droplet dilakukan di laboratorium sprayer. Pengujian kinerja lapangan dilakukan melalui aplikasi sprayer pada penyemprotan pestisida pada tanaman jagung. Parameter yang diukur adalah kapasitas lapangan efektif dan penutupan daun untuk selanjutnya menghitung efisiensi lapangan penyemprotan dan biaya aplikasinya. Parameter-parameter tersebut dibandingkan antara masing-masing sprayer dengan metode pengambilan keputusan Comparative Performance Index (CPI). Menurut metode pengambilan keputusan CPI, sprayer terbaik dalam penyemprotan adalah mist blower dengan penutupan daun sebesar 22,17%, biaya aplikasi sebesar Rp 885.922,29/ha, dan efisiensi lapangan penyemprotan sebesar 76,97%. Kapasitas lapangan efektif mist blower sebesar 0,29 ha/jam., The types of sprayers sold in the market are very diverse and each type has its own uniqueness. Three types of carrying type sprayers are commonly used, namely knapsack sprayers, knapsack power sprayers, and mist blowers, which need to be evaluated for the performance of spraying pesticides on corn plants. The aim of this study was to determine and compare the performance of knapsack sprayers, knapsack power sprayers, and mist blowers in spraying pesticides on corn plants. Measurement of the effective spraying width, discharge, and droplet diameter was carried out in the sprayer laboratory. Field performance testing was carried out through the application of a sprayer on pesticide spraying on corn plants. The parameters measured were effective field capacity and leaf surface coverage to further calculate field efficiency and application costs. These parameters were compared between each sprayer using the Comparative Performance Index (CPI) decision-making method. According to the CPI decision-making method, the best sprayer for spraying is a mist blower with a leaf cover of 22.17%, an application cost of Rp. 885,922.29/ha, and a spraying efficiency of 76.97%. The effective field capacity of the mist blower is 0.29 ha/hour.
Keyword: biaya aplikasi, jagung, kapasitas lapangan efektif, penutupan daun, performa

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