Judul: Sistem Kontrol Kendali Berbasis GPS dan Mikrokontroler Arduino Mega untuk Alat Penyemprot Padi Tipe Balon
Abstrak: Penyemprotan pupuk dan pestisida merupakan kegiatan pemeliharaan padi yang sangat memengaruhi produktivitas tanaman padi. Kegiatan ini umumnya menggunakan alat penyemprot tipe gendong. Mekanisme penyemprotan dilakukan oleh petani dengan berjalan diantara alur tanam padi. Hal ini akan merusak alur tanam dan petani akan mengalami kesulitan berjalan di lahan persawahan. Hal tesebut dapat diatasi dengan menggunakan sistem penyemprot melalui udara (aerial sprying). Penyemprotan ini sudah dilakukan dengan menggunakan pewasat terbang. Akan tetapi penggunaan pesawat memiliki kelemahan yaitu kebisingan, biaya yang mahal, dan adanya aturan untuk pesawat tidak terbang rendah di pulau jawa karena banyak kabel bertegangan tinggi. Solusi lain yang mungkin dilakukan yaitu dengan menggunakan balon yang dilengkapi sistem kontrol kendali. Pada penelitian ini gas hidrogen dipilih karena memiliki daya angkat yang lebih besar dibandingkan dengan gas helium atau balon udara panas. Sistem kontrol balon mengadopsi sistem kontrol multikopter (quad copter). Sistem kontrol tersebut dilengkapi dengan GPS sebagai modul pada flying control (Dji Naza). Pengendalian ini dilengkapi indikator ketinggian yaitu Arduino yang dihubungkan dengan sensor ultrasonik. Penelitian ini menggunakan balon dengan volume 221 m3 dengan daya angkat 14.2 kg pada ketinggian 1.5 meter. Sistem kontrol kendali mampu mengendalikan alat penyemprot tipe balon dengan kecepatan maju 1.16 m/s dan waktu berbelok 20 s pada kecepatan angin 1.13 m/s.
Keyword: arduino, dji naza, sistem kontrol kendali, dan quadcopter

Judul: Rancang Bangun dan Pengujian Unit Penyemprot pada Alat : Penyemprot Padi Tipe Balon
Abstrak: Spraying of fertilizers and pesticides on rice field is one of important maintenance activities for rice crop cultivation. Usually this activity is done in the morning because the wind conditions which allow the fertilizers or pesticides to be uniformly spread to field and to avoid drift. The activity is generally carried out manually by farmers using knapsack sprayer and the farmer had to walk between rice plant, which is laborious and can damage the planting furrow. Spraying application using tractor could not be done because of the condition of rice field, where almost field haven’t hardpan. These problems can be overcome by aerial spraying using air planes. The use of plane for spraying has some drawback such as high cost and safety related to ground condition. Another possible solution is to use a balloon equipped by control system and sprayer system for liquid fertilizer or pesticide application. Control system adopted the multi copter with flying board and for spraying systems adopted the electric sprayer. Spraying system used an electric pump for distribute the fertilizer or pesticide. Washer pump used for this prototype, the washer pump can produce a debit 1.20 l/min. The system created can do the spraying area 2.52 m2 per second equal to 0.91 ha/hour when the velocity 4.17 km/hour.
Keyword: Bogor Agricultural University (IPB), paddy sprayer, electric sprayer, balloon type sprayer, aerial spraying

Judul: Characterizations of low alloy steel sae 4422  plated with chromic acid (Cro3)
Abstrak: Characterizations of low alloy steel SAE 4422 plated with chromic acid (CrOrO3) was use Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), RD),Energy Dispersive Analysis of X-Ray (EDAX), Hardness Test and Roughness Test. Microstructures analysis exhibits cracks and grain boundaries microcracks as a characteristics of chrome metal found at plating metal. Perlite and Ferrite as grains of steel found at base metal with grain boundaries around it. Phase analysis of plating metal appropriate to chrome metal with lattice constant (a) is 2.559 Å and phase analysis of base metal appropriate to iron ferrite with lattice constant (a) is 3.318 Å. Both plating and base metal have cubic system. Chemical analysis of plating metal at surface section exhibits that cracks area have highest value of carbon element compare with grains and grains boundaries area. While chemical analysis of base metal at cross section exhibits that perlite have highest value of carbon element compare with ferrite and grain boundaries. The hardness value of plating metal at surface section and cross section are 753 and 637 VHN. While, the hardness value of base metal and interface area at cross section are 205 and 373 VHN. The roughness value at measurement points of chrome surface for as received sample are 0.445 μm. Observation used Optical Microscopy and Scanning Electron Microscopy exhibits surface irregularities combine to form surface texture of plating metal at surface section.
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