Judul: Isolasi dan Karakterisasi Kolagen dari Kulit Ikan Buntal Pisang (Tetraodon lunaris)
Abstrak: Kolagen merupakan salah satu jenis protein yang banyak terkandung dalam tubuh hewan dengan proporsi sekitar 30% dari total protein dalam tubuh secara keseluruhan. Pemanfaatan limbah kulit ikan buntal pisang menjadi kolagen adalah salah satu alternatif untuk meningkatkan nilai jual limbah. Tujuan penelitian ini adalah untuk mengisolasi dan mengkarakterisasi kolagen yang berasal dari kulit ikan buntal pisang. Pretreatment yang digunakan yaitu perbedaan konsentrasi NaOH (0,05; 0,1; dan 0,2 M) dan lama waktu perendaman (2, 4, 6, dan 8 jam). Pretreatment terbaik yang didapatkan yaitu konsentrasi NaOH sebesar 0,1 M dengan lama peredaman 6 jam karena dapat menghilangkan protein non-kolagen secara maksimum dengan nilai protein terlarut paling kecil yaitu 0,142 mg/ml. Rendemen kolagen yang dihasilkan yaitu 8,65%. Kolagen memiliki nilai pH 5,49 dan kelarutan 79%. Analisis spektra Fourier transform infrared (FTIR) menunjukkan wilayah penyerapan utama amida A, B, I, II, dan III masing-masing pada 3310, 2935, 1651, 1551, dan 1242 cm-1. Spektroskopi FTIR menunjukkan bahwa molekul kolagen memiliki struktur heliks tiga yang kompak stabil oleh ikatan hidrogen.
Keyword: FTIR, ikan buntal, kolagen, NaOH, rendemen

Judul: Ekstraksi dan Karakterisasi Kolagen dari Kulit Ikan Tongkol (Euthynnus affinis)
Abstrak: Collagen is the most abundant protein in the living body and comprising approximately 30% of the total protein content. Utilization of waste from the skin of eastern little tuna to produce collagen is one alternative to increase the economic value of its waste. Pretreatment process in extracting collagen affects the quality of collagen that obtained. The different concentration of NaOH (0.05; 0.1; and 0.2 M) and soaking time (2, 4, 6, 8, 10, and 12 hours) were used as the pretreatment step. The best result of pretreatment was obtained from soaking the skin in a solution of 0.05 M NaOH for 12 hours with the lowest of soluble non-collagen protein concentration was 0.140 mg/mL. The yield and pH of the best collagen were 7.459% and 5.29, respectively. The highest solubility of collagen was 90.80% at pH 3. Amino acid analysis showed that the collagen has a glycine, proline, arginine, and alanine were dominant. FTIR analysis showed the major absorption bands of amide A, B, I, II, and III were at wavenumber 3395 cm-1, 2929 cm-1, 1652 cm-1, 1543 cm-1, and 1237 cm-1, respectively.
Keyword: amino acid, collagen, eastern little tuna, FTIR, yield

Judul: Tinjauan Matematis pada Model Makroskopik dan Mikroskopik Arus Lalu-lintas
Abstrak: Traffic flow phenomenon can be described through mathematical model such as continuous dynamic model with an ordinary differential equation so that it can be solved with integral factors. In this paper three simple models of traffic flow are discussed, i.e, two macroscopic and one microscopic models. Macroscopic model formulates dynamics of the traffic flow that occurs on a large number of vehicles on a road. While the microscopic model explains drivers’ behavior in their interaction with other vehicles ahead, i.e, car-following model. This paper shows the existence of ordinary differential equation found in the traffic flow model and indicates some different representations in the context of the same model. It also reviews a simple model of traffic flow along a single link, which leads to some unexpected results, i.e, it can express the solution model in term of link outflows as well as trip time. In the microscopic model, simulation is done to illustrate the behavior of the drivers with a sensitivity coefficient as a benchmark parameter.
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