Judul: Kajian Pemupukan fosfor Terhadap Pertumbuhan dan Produksi Antosianin Dua Aksesi Rosela (Hibiscus sabdariffa L.).
Abstrak: Roselle (Hibiscus sabdariffa L.) is a common herb plant that contain high anthocyanin. This research on roselle was conducted in 2009 at Cikabayan Research Center, IPB. The purpose of the research was to study the effect of phosphorus fertilizer on anthocyanin content in two lines of roselle. This research used Split Plot Design with two factors and three replications. The main plot was lines of roselle i.e. red and purple.The sub plot was dosage of phosphorus i.e: 0, 18, 36, and 54 kg P2O5/ha. At 16 days after planting, calyx was taken to analyze anthocyanin content with spectrophotometer using Sims and Gamon (2002) method. The result of this study showed that dosage of phosphorus has no significant effect for several vegetative and generative variables on both of red and purple lines, but it has significant effect for the number of secondary branch per plant at 11 week after planting (WAP), the number of leaf per plant at 9 WAP, fresh weight of shoot per plant, and dry weight of fruit. The study also has very significant effect for the number of height per plant at 11 WAP, the number of primary branch per plant at 7 WAP, dry weight of shoot per plant, fresh and dry weight of total shoot per slot (20m2), as well as fresh and dry weight of calyx per slot (20m2). The optimum content of anthocyanin per calyx and production of anthocyanin per plant found on purple lines and 54 kg P2O5/ha that were 3.68 mmol/g and 6.85 mol/plant.
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Judul: Pendugaan Umur Simpan Kelopak Bunga Rosela (Hibiscus sabdariffa L.) Kering.
Abstrak: Roselle is a kind of plant from genus Hibiscus. Calyx of roselle flower from variety of sabdariffa has a lot of uses as a food material. Utilization of roselle (Hibiscus sabdariffa L.) has increased because many researches mentioned that roselle have chemical content which have many functions for human health, especially high content of vitamin C. Prediction of shelf life aims to know shelf life of dry calyx of roselle in certain condition. Determination shelf life product with ASS (Accelerated Storage Studies) method using environmental condition parameter enables to accelerate degradation process of quality of food product. The right packaging and storage is expected to increase shelf life and detain deterioration rate of dry calyx of roselle. The objectives of the research is to know quality changing, to determine shelf life, and to obtain better packaging to defend quality of dry calyx of roselle. The packaging materials which are used in this research were craft paper and plastic PP. Storage temperatures are held at 25°C, 35°C, and 45°C. Storage time in this research is 3 months. The analysis of dry calyx of roselle were water content, total of acid titration, total soluble solid, pH, vitamin C content, total mould, and sensory evaluation analysis. Based on this research, it is showed that dry calyx of roselle quality changed during 3 months of storage. Water content of dry calyx of roselle in craft paper packaging at storage temperature of 25°C increased by 0.12% per day and at temperature of 35oC and 45°C decreased by 0.03% and 0.04% per day respectively. In plastic PP packaging, water content of roselle at storage temperature of 25°C and 35°C increased by 0.06% and 0.04% per day respectively, while at 45°C it decreased by 0.03% per day. Total of acid titration of dry calyx of roselle in craft paper packaging at storage temperature of 25°C, 35°C, and 45°C decreased by 0.0007% per day, while in plastic PP at temperature of 25°C, 35°C, and 45°C decreased by 0.0008%, 0.0009%, and 0.0016% per day respectively. pH of dry calyx of roselle in craft paper packaging at storage temperature of 25°C, 35°C, and 45°C decreased by 0.0004% per day, while in plastic PP packaging at 25°C, 35°C, and 45°C, it decreased by 0.0003%, 0.0004%, and 0.0005% per day respectively. Vitamin C of dry calyx of roselle at storage temperature of 25°C, 35°C, and 45°C in craft paper packaging decreased by 0.0072%, 0.0136%, and 0.0142% per day respectively, while in plastic PP, it decreased by 0.0096%, 0.0161%, and 0.0166% per day respectively. Total soluble solid of dry calyx roselle in craft paper at 25°C, 35°C, and 45°C of storage temperatures increased by 0.0061%, 0.0067%, and 0.0077% per day respectively. In plastic PP, total soluble solid of dry calyx roselle at storage temperature of 25°C, 35°C, and 45°C increased by 0.0060%, 0.0071%, and 0.0076% per day respectively. During 3 months of storage, there was no mould found in dry calyx of roselle. There was no panelists refusal at assessment of common acceptance attribute of dry and extract calyx of roselle until 91 days of
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Judul: igenvalues and Eigenvectors of Tridiagonal Matrix with Non Constant and Recurrent Diagonal Entries.
Abstrak: Matriks tridiagonal adalah suatu matriks yang mempunyai entri-entri bernilai nol kecuali pada diagonal utama, di bawah diagonal utama (subdiagonal) dan di atas diagonal utama (superdiagonal). Entri pada diagonal utama tidak konstan dan berulang. Setiap entri pada matriks tridiagonal ini adalah bilangan kompleks. Dalam karya ilmiah ini, akan dibuktikan 3 teorema untuk menentukan nilai eigen dengan 2 kasus dan 1 teorema untuk menentukan vektor eigen. Teorema pertama menentukan polinomial karakteristik dari matriks tridiagonal. Polinomial karakteristik dari matriks tridiagonal tersebut digunakan untuk menentukan nilai eigen pada teorema kedua dan ketiga serta menentukan vektor eigen pada teorema keempat
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