Judul: The Effects of Light Emitting Diode (LED) Spectrum and Hormone Treatment by Cooling the Root Zone on The Growth of Strawberries in The Lowlands
Abstrak: Modifikasi lingkungan tumbuh stroberi yang dapat dilakukan dengan penggunaan LED sebagai cahaya buatan dan aplikasi chiller untuk pendinginan daerah perakaran. Penelitian ini bertujuan mengetahui pengaruh perbedaan spektrum warna LED dan aplikasi hormon terhadap pertumbuhan tanaman stroberi dengan pendinginan daerah perakaran. Penelitian ini menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) dengan dua faktor berupa jenis cahaya LED biru, merah, kombinasi merah-biru (1:1) selama 21 jam dan pemberian hormon metil jasmonat 0,50 mmol l-1 dan metil salisilat 0,25 mmol l-1. Hasil penelitian menunjukkan bahwa pertumbuhan tunas daun baru terbanyak pada perlakuan LED biru-metil jasmonat sebanyak 31 tunas daun. LED biru-metil salisilat memiliki nilai pertumbuhan pucuk tertinggi, yaitu 16 cm. Pengukuran kandungan glukosa yang tertinggi pada perlakuan LED biru-metil Salisilat, yaitu 0,260 µg ml-1, nilai kandungan fruktosa tertinggi terdapat pada perlakuan biru-metil jasmonat yaitu sebesar 0,139 µg ml-1., Environmental modification for strawberry cultivation can be done by using LED as artificial light and chiller application for cooling the root area. This study aims to determine the differences in the LED light spectrum and hormone application on the growth of strawberry plants under cooling the root zone. This study used a Completely Randomized Block Design (CRBD) with two factors, namely the types of LED light blue, red, red-blue combination (1:1) for 21 hours and application of 0.50 mmol l-1 of methyl jasmonate and methyl salicylate 0.25 mmol l-1. The results showed that the highest growth of new leaf shoots in the LED blue-methyl jasmonate treatment was 31 leaf shoots. LED blue-methyl salicylate had the highest shoot growth value, which was 16 cm. The measurement of the highest glucose content in the LED blue-methyl salicylate treatment was 0.260 µg ml-1, the highest fructose content value was found in the blue-methyl jasmonate treatment, was in 0.139 µg ml-1.
Keyword: chlorophyll, fructose, glucose, methyl jasmonate, methyl salicsylate

Judul: Effects of Spectrum and Ilumination Time of Light Emitting Diode (LED) on Physiology and Secondary Metabolite Profiles of Strawberries in Lowlands
Abstrak: Stroberi sebagai buah dengan antioksidan tinggi memiliki perbedaan fisiologi dan metabolit sekunder yang bergantung dengan teknik budidayanya. Salah satu perlakuan modifikasi lingkungan yang dapat dilakukan adalah penggunaan LED sebagai cahaya buatan. Penelitian bertujuan mengetahui jenis cahaya dan waktu penyinaran LED terhadap fisiologi dan metabolomik stroberi. Penelitian menggunakan rancangan acak kelompok (RAK) dengan dua faktor berupa jenis cahaya LED (biru, merah, kombinasi merah-biru dan putih) dan waktu penyinaran (15 jam, 18 jam dan 21 jam). Hasil penelitian menunjukkan bahwa LED biru 18 jam memiliki efektivitas dalam meningkatkan pertumbuhan pucuk. Penggunaan LED kombinasi dengan waktu penyinaran 15 jam dan 21 jam memiliki hasil terbaik dalam akumulasi klorofil, glukosa dan fruktosa. Senyawa metabolit umum yang ditemukan berupa, tyrasol, phytol, asam linoleat, asam palimtat, vitamin E dan clionasterol. Senyawa spesifik banyak ditemukan di perlakuan kontrol dan LED merah., Strawberries are a fruit with high antioxidants, have differences in physiology and secondary metabolite profiles that depend on their cultivation technique. One of the cultivation technique treatments is the use of LEDs as artificial light. This research was aimed to determine the type of light and photoperiod that can optimize the physiology and metabolomics of strawberries using LEDs. The study used a randomized block design (RBD) with two factors, the type of LED light (blue, red, combination of red-light, and White) and photoperiod (15 hours, 18 hours, and 21 hours). The results showed that the 18 hours blue LED was effective in increasing shoot growth. The combination of LED uses with 15 hours and 21 hours has the best results in the accumulation of chlorophyll, glucose, and fructose. Common metabolite compounds found are tyrasol, phytol, linoleic acid, palmitic acid, vitamin E and clionasterol. Specific compounds were found in the control and red LED treatments.
Keyword: chlorophyll, glucose, LEDs, secondary metabolite, strawberry

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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