Judul: Growth of Potato Plants (Solanum tuberosum L.) var. Atlantic and Super John in Response to Lighting Period of Fluorescent Lamp in Aeroponic System.
Abstrak: This study was conducted to find out responses of growth of seed potato (Solanum tuberosum L. var. Atlantic and Super John) to different lighting period of fluorescent lamp in an aeroponic system. The light source was provided by 40 W fluorescent lamps under 12 and 24 hours lighting. The total power was 320 W (8x 40 W) for 2.4 m2 with the distance between the light sources (lamps) and the plants was 30 cm. In this aeroponic system, the environmental condition which had low light intensity (average of 1149 lux or 9 W/m2.) and low humidity (48-53%) resulted a negative impact to the plant growth. The range of diurnal room temperature was 20.0 . 26.5 ¢ªC. Water was automatically sprayed for 13 seconds at 7 minutes interval to ensure the plant has sufficient water and nutrients. Plant growth was measured from total number of leaves. The study resulted that 24 hours lighting period had better effect on growth than 12 hours lighting period. The growth of Atlantic variety was better than Super John in response to the low intensity of light shown by higher leaf number both in 12 hours and 24 hours lighting period.
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Judul: Pakcoy Plant Growth (Brassica rapa L. subsp. chinensis (L.) Hanelt) under some Artificial Lighting in a Wick Hydroponic System
Abstrak: Cahaya merupakan faktor yang sangat penting bagi pertumbuhan tanaman, namun cuaca yang fluktuatif di Indonesia mempengaruhi penerimaan sinar matahari oleh tanaman. Pencahayaan buatan, seperti light emitting diode (LED) surface mounted device (SMD), dapat berfungsi sebagai sumber cahaya alternatif. Penelitian ini bertujuan untuk melihat pengaruh jenis pencahayaan buatan yaitu pencahayaan alami (sinar matahari), LED SMD 5050, LED SMD 5730 dengan lama waktu pencahayaan buatan tunggal yaitu 20 jam, serta lama waktu pencahayaan buatan tambahan yaitu 8 jam pada tanaman pakcoy. Pakcoy dibudidayakan dengan sistem hidroponik sumbu (wick). Parameter tanaman yang dievaluasi meliputi jumlah daun, tinggi tanaman, luas kanopi tanaman, dan berat total biomassa selain akar. Hasil penelitian menunjukkan bahwa tanaman yang dipapar LED SMD 5730 selama 20 jam menunjukkan rata-rata tinggi tanaman, jumlah daun, berat biomassa selain akar, dan luas kanopi tertinggi. Namun hasil ini tidak lebih baik dari tanaman yang diberikan pencahayaan matahari saja (kontrol). Hasil tanaman yang paling buruk merupakan tanaman yang diberikan perlakuan pencahayaan buatan dengan LED SMD 5050 selama 20 jam. Sehingga, berdasarkan hasil penelitian yang dilakukan LED SMD 5730 merupakan sumber pencahayaan buatan yang lebih baik daripada LED SMD 5050., Light is a crucial factor for plant growth, but the fluctuating weather in Indonesia affects the reception of sunlight by plants. Artificial lighting, such as SMD LEDs, can serve as an alternative light source. This study aims to assess the effects of different artificial lighting types, including natural lighting (sunlight), LED SMD 5050, and LED SMD 5730. The lighting durations tested were twenty hours of continuous artificial lighting and eight hours of supplementary artificial lighting on pakcoy plants grown using a wick hydroponic system. Several plant parameters were evaluated, including the number of leaves, plant height, plant canopy area, and total biomass weight excluding roots. Results showed that the plants exposed to SMD 5730 LEDs for twenty hours exhibited the highest average plant height, number of leaves, total biomass weight excluding roots, and canopy area. However, these outcomes did not surpass the control group exposed only to sunlight. Conversely, the plants treated with 5050 SMD LED for twenty hours demonstrated the lowest yields. Consequently, the research findings suggest that SMD 5730 LEDs are a superior artificial lighting source compared to 5050 SMD LEDs.
Keyword: artificial lighting, LED SMD, pakcoy, wick hydroponic

Judul: Dekomposisi Nilai Singular pada Matriks Kompleks Toeplitz Bidiagonal Atas.
Abstrak: Dekomposisi nilai singular merupakan salah satu metode faktorisasi matriks berdasarkan nilai singular dan vektor singularnya. Dekomposisi nilai singular bertujuan untuk memfaktorisasi suatu matriks �������� berukuran �������� × �������� menjadi bentuk �������������������������������� dengan �������� merupakan matriks berukuran �������� × �������� , �������� merupakan matriks berukuran �������� × �������� dan �������� merupakan matriks berukuran �������� × ��������. Pada karya ilmiah ini, dibahas dekomposisi nilai singular pada matriks kompleks Toeplitz bidiagonal atas berukuran �������� × (�������� + 1).
Keyword: dekomposisi nilai singular, matriks Toeplitz, matriks bidiagonal atas, matriks kompleks