Judul: Uji Performansi Alat Pengering Tipe Rak dan Pengaruh Perlakuan Awal terhadap Mutu Jahe Kering (Zingiber officinale Rosc.)
Abstrak: Ginger (Zingiber officinale Rosc.) is one of spices and medicinal plant which has high economic value and have been widely recognized by the Indonesian people. Fresh ginger has moisture content between 85-91% wet basis causes reduction quality of ginger if it is not eventually to be processed or dried. Generally, farmers and traders dried the ginger by using sun drying which require a lot of time, so that the artificial drying is needed to produce dried ginger with better quality and can shorten the drying time. The objectives of the research are to conduct the performance assessment of Sunbeam Food Dehydrator, which is rack-type dryer that using electrical energy as heat source; to assess the effect of immersion in lime solution (Ca(OH)2) at concentration of 2%, 4% and 6% to the quality of dried ginger; as well as studying the temperature distribution and air flow patterns in the dryer using Computational Fluid Dynamics (CFD). The results of the research showed that the dryer has capacity about 1kg of ginger slice and drying efficiency of 25.09%. It also shown that the immersion in lime solution gave a significant effect on increasing ash content and lightness of dried ginger, but it gave no significant effect on essential oil content of dried ginger. The treatment of immersion in 6% concentration of lime solution produce dry ginger with ash content that beyond of quality standard limit. The simulation of temperature and air flow patterns inside the dryer showed the accuracy of 97.09% and resulting linear regression of the relationship between measurement temperature and simulation temperature of 0.943. This shows that the CFD simulation gives good results in predicting the distribution of air temperature and air flow patterns inside the dryer.
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Judul: Mempelajari karakteristik pengeringan jahe (Zingiber officinale Rosc.) dengan alat pengering tipe rak
Abstrak: Permintaan komoditi jahe di dalam negeri yang meningkat dan makin berkembangnya industri tradisional menunjukkan industri jahe mempunyai prospek yang cerah. Sementara itu, ekspor jahe kering Indonesia belum bisa memenuhi permintaan negara konsumen. Karena itu perlu terus diadakan penelitian proses pengeringan jahe untuk meningkatkan hasil dan mutu jahe kering. Penelitian ini bertujuan mempelajari karakteristik pengeringan jahe yang meliputi perubahan kadar air terhadap waktu pengeringan, perubahan laju pengeringan terhadap waktu pengeringan, penentuan nilai kadar air kesetimbangan dan konstanta pengeringan pada proses pengeringan jahe dengan empat tingkat suhu yaitu 40°C, 45°C. 50°C dan 55°C serta dua tingkat kecepatan aliran udara yaitu 1.0 m/dt dan 2.0 m/dt, penentuan model persamaan pengeringan lapisan tipis jahe berdasarkan model persamaan pengeringan Nishiyama (1982), perlakuan uji organoleptik yang meliputi penampakan produk, tekstur, warna dan bau jahe kering. penghitungan koefisien rehidrasi, tegangan tarik statik dan rendemen jahe kering. Peralatan penelitian yang digunakan adalah Tray Dryer, Chromameter, force gauge, timbangan, desikator, alat pengukur kecepatan aliran udara, oven dan termometer. ...
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Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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