Judul: Response of growth and productivity on red lettuce (lactuca sativa var. Crispa) to irrigation volume and fertilizer frequency with sandphonics
Abstrak: Penelitian ini dilakukan untuk mempelajari adanya pengaruh volume irigasi dan frekuensi pemupukan terhadap pertumbuhan produksi selada merah (Lactuca Sativa Var. Crispa), dengan media hidroponik pasir. Percobaan menggunakan rancangan kelompok lengkap teracak (RKLT) terdiri dari dua faktor tiga ulangan. Faktor pertama adalah volume irigasi terdiri atas 4 taraf yaitu, I1(1xEo), I2(2xEo), I3(3xEo), I4(4xEo). Faktor kedua adalah frekuensi pemupukan yang terdiri atas 4 taraf yaitu, F1: 4 hari sekali, F2: 6 hari sekali, F3: 8 hari sekali, F4:12 hari sekali, dengan konsentrasi yang sama disetiap perlakuannya yaitu 1.5 g/l. Volume irigasi 4Eo memberikan pengaruh yang sangat nyata pada tinggi tanaman dan jumlah daun berumur 2, 3, dan 4 MST (Minggu Setelah Tanam), bobot total basah, bobot tajuk atau bobot pasar tanaman, bobot kering total tanaman, ratarata panjang dan lebar daun tanaman saat panen. Frekuensi pemupukan 4 hari sekali memberikan pengaruh yang sangat nyata pada tinggi tanaman dan jumlah daun berumur 2, 3, dan 4 MST, bobot total basah, bobot tajuk atau bobot pasar tanaman, bobot kering total tanaman, rata-rata panjang dan lebar daun tanaman saat panen. Pengaruh interaksi antara frekuensi pemupukan dengan volume irigasi yang dihasilkan pada tanaman selada merah berbeda nyata terhadap jumlah daun pada 2, 3, dan 4 MST, bobot total basah tanaman, bobot tajuk atau bobot pasar tanaman, serta bobot kering total tanaman dengan nilai tertinggi pada perlakuan frekuensi pemupukan 4 hari sekali dan volume irigasi 4Eo, This research was conducted to study about effect of irrigation volume and fertilization frequency on Red Lettuce (Lactuca Sativa Var. Crispa) growth and production with sandphonics. The research was arranged in randomized completely block design, consisting of two factors with three replications. The first factor was irrigation volume consisted on four levels: I1(1xEo), I2(2xEo), I3(3xEo), I4(4xEo). The second factor was fertilization frequency consisted of four levels: F1: every 4 day, F2: every 6 day, F3: every 8 day, F4: every 12 day, with the same concentrate in every treatment is 1.5 g/l. The volume of irrigation 4Eo provide a significant influence on height of plant and amount of leaves was 2, 3, and 4 WAP (Weeks After Planting), wet weight, the weight of the plant canopy or marketable weight, total dry weight, average length and width of leaves at harvest. The frequency of fertilization 4 days gave a significant influence on height of plant and amount of leaves was 2, 3, and 4 WAP, total weight, the weight of the plant canopy or marketable weight, total dry weight, average length and width of leaves at harvest. Effect of the interaction between the frequency of fertilization with irrigation volume generated on the red lettuce plants was significantly different to the amount of leaves at 2, 3, and 4 WAP, the total wet weight of the plant, the weight of the plant canopy or market weight, and total plant dry weight with the highest value at the treatment of the frequency of fertilization every 4 days and the volume of irrigation 4Eo.
Keyword: hidroponik, hidroponik pasir, irigasi, selada merah, pemupukan

Judul: Pengaruh Volume Irigasi dan Frekuensi Pemupukan terhadap Pertumbuhan Produksi Pak Choi (Brassica rapa gp. Chinensis) dengan Hidroponik Pasir
Abstrak: This research was conducted to study about effect of irrigation volume and fertilization frequency on Pak Choi (Brassica rapa gp. Chinensis) growth and production with sandphonics. The experiment was arranged in randomized completely block design, consisting of two factors with three replications. The first factor was irrigation volume consisted on four levels: I1(1xEo), I2(2xEo), I3(3xEo), I4(4xEo). The second factor was fertilization frequency consisted of four levels: F1: every 4 day, F2: every 6 day, F3: every 8 day, F4: every 12 day, with the same concentrate in every treatment is 1.5 g hidroponic fertilizer/l. Irrigation volume cause plant high is 3 Eo and 4 Eo, total of fresh wight on each pot is 2 Eo, and total of dry root weight is 4 Eo. Fertilization frequency cause the highest leaf number for the ages of plant is 4 weeks after planting, the average of leaf width, total of fresh weight, and total of dry weight is 4 day. The highest production resulted by irrigation volume treatment in the amount of 2 Eo and fertilization frequency in every 6 day.
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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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