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: Kinerja Sprayer Elektrik Pompa Ganda Menggunakan Mobile Sprayer Machine untuk Pemupukan Cairan pada Budidaya Bawang Daun
Abstrak: Penyemprotan pupuk cair menggunakan sprayer elektrik pompa ganda mampu menghasilkan droplet nutrisi untuk dapat diserap oleh stomata bawang daun sehingga dapat meningkatkan produktivitas tanaman. Tujuan dari penelitian ini adalah menganalisis dan menentukan kinerja sprayer elektrik pompa ganda dengan kombinasi pengaturan tipe nosel untuk pemupukan cair pada budidaya tanaman bawang daun menggunakan mobile sprayer machine. Penyemprotan dilakukan dengan menggunakan 4 perlakuan tipe nosel yaitu nosel kipas pipih, kerucut, shower 8 lubang, dan shower 5 lubang. Penelitian dilakukan dengan dua tahapan yaitu penelitian sprayer di laboratorium dan di lahan. Penelitian di laboratorium dilakukan untuk menentukan parameter penyemprotan meliputi Diameter dan kerapatan droplet, debit penyemprotan efektif, dan lebar penyemprotan efektif. Penelitian di lahan dilakukan untuk mengukur parameter keberhasilan pemupukan meliputi tinggi tanaman, jumlah anakan per rumpun, dan bobot tanaman. Berdasarkan pengukuran parameter pembobotan hasil uji kinerja, penyemprotan yang optimum dihasilkan saat menggunakan nosel kerucut yang mampu menghasilkan diameter droplet sebesar 107.05 μm, kerapatan droplet sebesar 319.36 droplet/cm2 , debit penyemprotan efektif sebesar 0.71 liter/menit, dan lebar penyemprotan efektif sebesar 0.96 m. Keberhasilan pemupukan yang optimum ditunjukkan pada perlakuan T3N2 dengan rata-rata tinggi tanaman dan jumlah anakan per rumpun sebesar 37.06 cm dan 14.30 anakan pada umur 56 HST, serta bobot tanaman sebesar 37.98 gram., Spraying liquid fertilizer using a double pump electric sprayer is able to produce nutrient droplets to be absorbed by the stomata of spring onion so that can increase plant productivity. The purpose of this study was to analyze and determine the performance of a double pump electric sprayer with a combination of nozzle type settings for liquid fertilization in spring onion cultivation using a mobile sprayer machine. Spraying was carried out using 4 types of nozzle treatments, that is flat fan, cone, shower with 8 holes, and shower with 5 holes nozzle. The research was carried out in two stages, that is sprayer research in the laboratory and in the field. Research in the laboratory was conducted to determine spraying parameters including droplet diameter and density, effective spraying discharge, and effective spraying width. Field research was conducted to measure the success of fertilization parameters including plant height, number of tillers per clump, and plant weight. Based on the measurement of the weighting parameters of the performance test results, the most optimum spraying is produced when using a cone nozzle which is capable of producing a droplet diameter of 107.05 μm, a droplet density of 319.36 droplet/cm2 , 0.71 liter/minute of effective spraying discharge, and 0.96 m of effective spraying width. The optimum fertilization success shown in the T3N2 treatment with an average plant height and number of tillers per clump of 37.06 cm and 14.30 tillers at the age of 56 DAP, and a plant weight of 37.98 grams.
Keyword: double pump electric sprayer, spring onion, liquid fertilizer, droplet

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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