Judul: Kajian pengaruh jenis kemasan polietilen dan polipropilen terhadap umur simpan buah Belimbing manis (Averrhoa carambola L.)
Abstrak: Star fruit is a fruit that spread out in Southeast Asia, including Indonesia. The shelf life of star fruit after postharvest are very short, so it is necessary to maintain the treatment method of star fruit quality to extend the shelf life of the fruit. One way to extend the star fruit shelf life is by package the fruit by choosing the right type of plastic. The type plastics that used in these experiments are low density polyethylene, high density polyethylene, and polypropylene. To find the right type of packaging in maintaining the quality of star fruit take several tests and storage at different temperatures in order to know the physical and chemical changes of the star fruit. Star fruit that has been packaged are stored in different temperatures (5 ° C, 10 °C, room temperature). The test that have been conducted is to determine the best packaging of respiration and the permeability test of plastic packaging color, hardness, soluble solids content, weights loss, and organoleptic. The results of several trials of star fruit during storage at 5 °C, 10 °C, and room temperature refers to the polypropylene plastic packaging that can maintain the quality of star fruit with a longer storage at optimum temperature of 10 °C.
Keyword: 

Judul: Kajian Teknik Pengemasan Buah Pepaya Dan Semangka Terolah Minimal Selama Penyimpanan Dingin
Abstrak: Papaya and Watermelon are one of the famous agriculture commodity. As a agriculture products, they are perishables. This is because papaya and watermelon are still doing metabolitic activity (respiration). The effect of papaya and watermelon respiration is chemical changing so that caused physical changing. The physical changing as a result of chemical changing could be perceived directly as a color, aroma, texture and flavour changing. People generally prefer to consumed them in cold condition. Before they are ready to consume, papaya and watermelon are processed minimally, including fruits cleaning, paring, and cutting into a smaller size so that make them more interesting and easier to consume. They also has a big size so they havenot finished consumed in once time. So, usually people cut them several time during consumption. Minimally processed cause injury in the fruits so that make it shorter in storage life. The way that we can do to prolong the storage life of the minimally processed of papaya and watermelon is a proper packaging and cold storage. The aim of the research is to get characteristic of packaging, physical, chemical, microbiology’s characteristic of fruits, and quality parameter changing and organoleptic assesment for cold storage according to the technique packaging. It also determine the suitable packaging for the fruits during cold storage. Storage were conducted at five treatment that is using polypropylene packaging with two opened circulation holes (B1), polypropylene packaging with one opened circulation hole (B2), polypropylene packaging with two closed circulation holes (B3), plate with cling film plastic cover (B4), plate with no cover (B5) and conducted in the chiller refrigator with 5 - 100C temperature. The parameter which were tested are proximate test (including water content, ash content, protein content, faty content and fiber content) and quality analysis including physical parameter (texture and color), chemical parameter (water content, total acid content, pH, total sugar content, Aw, vitamin C), microbiological test (TPC) and organoleptic test. The parameter were tested during 14 days storage. The result of research showed that thickness, gramature and density of polypropylene packaging is higher and transmission rate (O2, CO2, H2O) is lower than cling film plastic packaging. Characteristic of papaya and watermelon showed that both of them had a relatively high water content (> 80%), watermelon’s texture was lower than papaya’s, neutral’s pH (6.10 for papaya and 5.60 for watermelon), papaya and watermelon’s Aw were 0.82 dan 0.80. They also has a relatively low carbohydrates, protein, and fat. The result also showed that during storage was occurred the increasing microbiological test (TPC). It cause the increasing of water content (except in B5), decreasing of total sugar content, increasing of total acid and decreasing of pH, increasing of color brightness (except in B5), and 0Hue (except in B5 of watermelon) and also increasing of texture content. Organoleptic test showed that fruits that in plate with no cover (B5) had the highest decreasing than the other. Panelists still like the fruits that packed in all of polypropylene packaging (B1, B2, B3) until nine to twelve days, fruits in plate with cling film cover (B4) until eight
Keyword: 

Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix