Judul: Kinerja Sprayer Gendong Bermotor untuk Pemupukan Cair pada Budidaya Jagung
Abstrak: Pemupukan cair menggunakan sprayer gendong bermotor mampu menghasilkan droplet nutrisi yang diserap stomata tanaman jagung sehingga dapat meningkatkan produktivitas jagung. Penelitian ini bertujuan menentukan dan menganalisis kinerja sprayer gendong bermotor untuk pemupukan cair tanaman jagung pada beberapa pengaturan jumlah dan tipe nosel. Pengaturan jumlah nosel yang digunakan adalah 1 nosel, 2 nosel, dan 4 nosel yang dikombinasikan menggunakan nosel tipe kipas dan tipe kerucut. Penelitian di laboratorium (indoor testing) dilakukan untuk mengukur parameter utama penyemprotan meliputi debit penyemprotan efektif, lebar penyemprotan efektif, diameter dan kerapatan droplet. Penelitian di lapangan (outdoor testing) dilakukan untuk mengukur parameter keberhasilan pemupukan cair meliputi tinggi tanaman, hari pemunculan bunga, diameter dan bobot tongkol berkelobot. Hasil penelitian menunjukkan bahwa kinerja sprayer gendong bermotor optimum pada bukaan throttle 50% menggunakan 4 nosel kerucut dengan diameter droplet 167.37 μm, kerapatan droplet 352.56 droplet cm-2, lebar penyemprotan efektif 160 cm, tinggi penyemprotan efektif 67.19 cm, dan debit penyemprotan efektif 5.22 liter menit-1. Keberhasilan pemupukan cair ditunjukkan dengan pemunculan bunga betina dan jantan pada umur tanaman 40 HST (hari setelah tanam) dan 47 HST, rata-rata tinggi tanaman 210.93 cm pada umur 57 HST, diameter tongkol berkelobot 6.2 cm buah-1, serta bobot tongkol berkelobot 406.5 gram buah-1., Liquid fertilization using a motorized carrying sprayer is able to produce a nutrient droplet absorbed by the stomata of corn plants so that it can increase corn productivity. This study aims to determine and analyze the performance of a motorized carrying sprayer for liquid fertilization of corn plants in several regulation of the number and type of nozzle. The number of nozzles used is 1 nozzle, 2 nozzles, and 4 nosels combined using fan type nozzles and cone types. Research in the laboratory (indoor testing) is carried out to measure the main parameters of spraying including effective spraying discharge, effective spraying width, diameter and droplet density. Research in the field (outdoor testing) is carried out to measure the success of the success of liquid fertilization covers the height of the plant, the day of the flower appearance, diameter and weight of the cob. The results of the study showed that the optimum motorized driving sprayer performance on 50% throttle openings used 4 cone nozzles with a diameter of droplet 167.37 μm, droplet density 352.56 droplet cm-2, effective spraying width 160 cm, high spraying effective 67.19 cm, and effective spraying discharge of 5.22 liters minute-1. The success of liquid fertilization is indicated by the appearance of female and male flowers at the age of 40 HST plant (day after planting) and 47 HST, the average plant height is 210.93 cm at the age of 57 HST, the diameter of the cob batches 6.2 cm fruit-1, and cob weight weights 406.5 gram fruit-1.
Keyword: droplet, optimum, penyemprotan, produktivitas, throttle

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: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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