Judul: Kajian Pengaruh Iradiasi Sinar Gamma Mortalitas Lalat Buah Dan Mutu Buah Mangga Gedong (Mangifera indica. L) Selama Penyimpanan
Abstrak: Mango cv. gedong is one of the potencial horticultural product to be exported, but mango is a host of fruit flies (Bactrocera dorsalis) that causing constrain with the quarantine regulation. Therefore, it need treatment to kill the fruit flies that invested inside the mango. Irradiaton treatment is one of disinfestation technique to kill the fruit flies add and keep fruit quality during storage. This research objective was to study the effect of irradiation gamma rays on fruit flies mortality and mango quality during storage. The doses at 0.25 kGy, 0.5 kGy, 0.75 kGy were used for mortality test on fruit flies invested mango. To see the effect of respiration and quality, the fruit were stored at 8, 13, 28 ºC (irradiation and control). The result shows that mortality of fruit flies B. papayae with the dose of 0.75 kGy reach 100%. Irradiation on the mango can decrease the growth of fruit fly, while on the control of manggo the fruit fly has been detected on the days 9th. The irradiotion treatment until the dose of 0.75 kGy is ineffective to eradicate the fruit fly that being infestations inside the mango, however, at 21 days of storage the fruit fly is still detected. The irradiation treatment with the dose of 0.75 kGy decrease respiration and postpone the fruit ripening also maintain the fruit quality based on the weight losses, the vitamin C content, total acid, TPT, and water content.
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Judul: Disinfestasi telur dan larva lalat buah pada buah mangga gedong gincu (Mangifera indica) dengan teknik perlakuan uap panas
Abstrak: The presence of fruitfly belongs to genus Bactrocera is the main problem of Indonesia’s program to export fresh mango. Subsequently, vapor heat treatment as one among suitable quarantine treatment methods had been developed to disinfest fruitfly in mango. This research was conducted with certain objectives such as: to observe thermotolerance of fruitfly against high temperature, to evaluate effect of treatment to the gedong gincu mango quality, and to determine the most effective level of vapor heat treatment that can be used to disinfest B. carambolae at laboratory scale. According to hot water dipping test, egg was the most tolerant stage, either on B. carambolae or B. papayae. In addition, eggs and larvae of B. papayae were more tolerant than those of B. carambolae at 46oC. While, increased temperatur comparison test show that mortality rate of B. carambolae larvae reach 100% after 20 minutes at 44ºC to 48ºC. On the other hand, all larvae were killed after 5 minutes treatment at 48ºC. There were no significant differences between treated and untreated gedong gincu mango in term of firmness, weight loss, peel color, sugar content and taste until 5 days after treatment at 45oC to 49oC. In laboratory scale, mortality of B. carambolae reach 100% at 46.5oC vapor heat on various holding time. This result show that vapor heat treatment at 46.5oC effectively killed eggs and larvae of B. carambolae. However, reducing the temperature might be effective if exposure time is prolonged. In the future, it is recommended to conduct large scale test for vapor heat treatment at 46.5o Keywords : fruitfly, gedong gincu mango, vapor heat treatment C as confirmatory test.
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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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