Judul: Performance of Electric Sprayer and Air Blower for Liquid Fertilizing on Water Spinach Cultivation System Based on The Different of Nozzle Types
Abstrak: The use of different nozzles on the sprayer for liquid fertilizing can affect plant growth and crop production. The purpose of this study was to analyze performance of an electric sprayer and an air blower for liquid fertilization on the growth and yield of water spinach based on the different types of nozzles. The main parameters of sprayer testing in the laboratory are droplet diameter, droplet density, effective spraying width and effective spraying rate. The performance of liquid fertilization is determined by the parameters of plant height, number of leaves, and fresh weight. The results showed that the use of an electric sprayer with four holes solid cone nozzle resulted in a minimum droplet diameter and a maximum droplet density of 208.01 µm and 130.62 droplets/cm2, respectively. This resulted in maximum yield of kale with plant height, number of leaves, and fresh weight of 29.14 cm, 17.2 strands, and 15.34 grams, respectively. The use of an electric sprayer and an air blower that produces a minimum droplet diameter and a maximum droplet density of 246.14 µm and 117.15 droplet/cm2 are five holes nozzle. This resulted in maximum yield of water spinach with plant height, number of leaves, and fresh weight of 27.29 cm, 13.9 strands, and 13.37 grams. The lowest application cost for electric sprayer was obtained in the double flat fan nozzle treatment of Rp 562 558.07/ha, while the electric sprayer and air blower on the six holes nozzle amounted to Rp 724 685.21/ha. Keywords: air blower, droplet, electric sprayer, liquid fertilizing, performance, Penggunaan perbedaan nosel pada sprayer untuk pemupukan cairan dapat mempengaruhi pertumbuhan serta hasil produksi (yield) tanaman. Tujuan penelitian ini adalah menganalisis kinerja sprayer elektrik dan air blower untuk pemupukan cairan terhadap pertumbuhan serta yield kangkung berdasarkan perbedaan jenis nosel. Parameter utama pengujian sprayer di laboratorium, yaitu diameter droplet, kerapatan droplet, lebar penyemprotan efektif dan debit penyemprotan efektif. Kinerja pemupukan cairan ditentukan oleh parameter tinggi tanaman, jumlah daun, dan bobot segar. Hasil penelitian menunjukkan penggunaan sprayer elektrik dengan four holes solid cone nozzle menghasilkan diameter droplet minimum dan kerapatan droplet maksimum berturut-turut sebesar 208.01 µm dan 130.62 droplet/cm2 . Hal tersebut menghasilkan yield maksimum kangkung dengan tinggi tanaman, jumlah daun, dan bobot segar berturut-turut sebesar 29.14 cm, 17.2 helai, dan 15.34 gram. Penggunaan sprayer elektrik dan air blower yang menghasilkan diameter droplet minimum dan kerapatan droplet maksimum berturut-turut sebesar 246.14 µm dan 117.15 droplet/cm2 adalah five holes nozzle. Hal tersebut menghasilkan yield maksimum kangkung dengan tinggi tanaman, jumlah daun, dan bobot segar sebesar 27.29 cm, 13.9 helai, dan 13.37 gram. Biaya aplikasi pupuk terendah sprayer elektrik diperoleh pada perlakuan double flat fan nozzle sebesar Rp562 558.07/ha, sedangkan sprayer elektrik dan air blower pada six holes nozzle sebesar Rp724 685.21/ha.
Keyword: air blower, droplet, electric sprayer, liquid fertilizing, performance

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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