Y. Rizal
Bandung Institute of Technology, Jln. Ganesha 10 Bandung

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Characteristics of Paleotsunami Sediments, A Case Study in Cilacap and Pangandaran Coastal Areas, Jawa, Indonesia Yudhicara, Yudhicara; Zaim, Y.; Rizal, Y.; Aswan, Aswan; Triyono, R.; Setiyono, U.; hartanto, D.
Indonesian Journal on Geoscience Vol 8, No 4 (2013)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2693.2 KB) | DOI: 10.17014/ijog.v8i4.166

Abstract

DOI: 10.17014/ijog.v8i4.166A paleotsunami study having been conducted in 2011 took two study cases in Cilacap and Pangandaran coastal areas. These two regions have been devastated by tsunami in the past and had the most severe damaged on 17 July 2006. Trenching, beach profiling, and sediment sampling had been carried out, and further analysis at the laboratory had been done, such as grain size and fossil analyses and dating. In Cilacap, an iron sand layer was found as a key bed suspected as a paleotsunami deposits due to the content of anthropogenic fragments. In Pangandaran, two layers of tsunami deposit candidates were found having thickness of 5 - 6 cm at the top as a 2006 tsunami deposit candidate, and 5 - 10 cm at the bottom as a paleotsunami deposit candidate. Both grain size and fossil analysis results could explain that Pangandaran’s sediments are tsunami deposits while Cilacap’s ones are assumed to be deposited by another process rather than a tsunami.
Determination of the best method for processing gambier liquid by-product [Uncaria gambir (hunter) roxb] as natural antioxidant sources Ismail, A. S.; Rizal, Y.; Armenia, A.; Kasim, A.
Journal of the Indonesian Tropical Animal Agriculture Vol 46, No 2 (2021): June
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jitaa.46.2.166-172

Abstract

The study was conducted to determine the best gambier liquid by-product (GLB) processing methods based on antioxidant activity as natural antioxidant sources. The processing methods were A (ethyl acetate fractionation), B (oven drying) and C (freeze drying) methods. The observed variables were dry extract (using weighing method), tannin (using hide powder method), catechin (using SNI 01- 339-2000 method), total phenol (using folin ciocalteu reagents) and antioxidant activities (DPPH method) based on ICAO50. These antioxidant activities were compared with vitamin C as a positive control. The results indicated that the different processing methods significantly affected (P<0.05) dry extract, tannin, catechin, total phenol and antioxidant activity of GLB. The highest dry extract, tannin, catechin, total phenol, and antioxidant activity from GLB were at treatment B (10.76%), B (39.69%), A (86.07%), C (80.97 mg GAE/g), and C (ICAO50 2.74 µg/mL), respectively. The antioxidant activity on treatment C was not different from vitamin C antioxidant activity (2.88µg/mL). Thus, the treatment C (freeze drying method) was the best method to process GLB based on antioxidant activity as natural antioxidant sources.