Judul: Aplikasi coating kitosan untuk memperpanjang umur simpan buah salak pondoh (Salacca edulis Reinw.)
Abstrak: Pondoh snake fruit is a tropical commodity which rapidly damaged during storage. The rain causes of damage due to respiration and fungal infection. Chitosan can be a coating material and inhibit the growth of fungal. Plastic has a permeabilities for O2, CO2, and H₂O ansfer. The purpose of this research is to know influences of chitosan coating and plastics packaging for shelf-life and qualities of pondoh snake fruit in some maturities level (80%, 90%, hatch) during storage. There are three steps of the methods, that was preparation chitosan coating Chitosan:acetic acid 1%) (b/v) 0.3:100; 0.5:100; 0.7:100, spray chitosan coating, and type of packaging material i.e. polypropyhlene without holes, polypropyhlene holes, polyetyhlene without oles, polyetyhlene holes and no packaging) then storage at temperature 16°C. The results howed that 80% maturity of pondoh snake fruit which coated by chitosan 0.5:100 chitosan:acetic acid 1%) (b/v) and packaged by polypropylene without holes have shelf-life until days, 90% maturity of pondoh snake fruit which coated by chitosan 0.7:100 (chitosan:acetic id 1%) (b/v) and packaged by polypropylene without holes have shelf-life until 12 days, batch maturity of pondoh snake fruit which coated by chitosan 0.5:100 (chitosan:acetic acid 1%) (b/v) and packaged by polypropylene without holes have shelf-life until 12 days. Pondoh snake fruit without treatment in room temperature was damaged until 100% in 6 days of storage. Qualities of pondoh snake fruit was decrease as storage in level of damage, weight loss, vitamin C, total acid, otal soluble solids, and organoleptic.
Keyword: Pondoh snake fruit, Chitosan coating, Polyethylene, Polyprophylene, cold storage

Judul: Aplikasi Teknik Pengemasan dan Coating Khitosan untuk Memperpanjang Umur Simpan Buah Salak Pondoh (Salacca edulis Reinw)
Abstrak: During the storage, performance of snake fruit will be spoiled quickly. Due to enzimatic reaction, chemical reaction, and microorganism activity. The purpose of this research was to determine the shelf life of snake fruit with chitosan coating packed in PP and PE bag. Snake fruit was cleaned and sprayed with 0.7% Chitosan water solution. Water used in this research was distilled water, bottled drinking water and tap water. Coated snake fruit the was packed in PP and PE bag in normal and vacuum condition. Once packed, snake fruit was stored at 16-17°C then it was analysed in every of 2-5 days. The parameters observed was Vitamin C, total acid, percentage of weights loss, total dissolved solid, and panels preference. snake fruit that coated with chitosan distilled water packed in PP bag gave the longest shelf life ie. 31 days, performance of snake fruit with best treatment was vitamin C of 1.37 mg/100g, total acid content of 0.003%, the percentage of weights loss of 0.01%, TSS of 14 °brix and the percentage of spoiled of 43% and by panels preference test samples are preferred PPTB (PP bag normal with bottled drinking water solution).
Keyword: Snake Fruit, Chitosan, Coating

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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