ALBERT

Description: Regional disaster data are important for understanding the characteristics of disasters and for identifying potential mitigation measures. However, many countries have no official disaster database that includes information such as numbers of deaths or damaged buildings for each disaster event. The Global Centre for Disaster Statistics (GCDS) was established to assist countries and organizations in the collection of disaster data. At present, a significant amount of tsunami disaster data are available from Indonesia, which will be used to demonstrate its application for analyzing vulnerability characteristics of historical tsunamis. There are 53 data points covering 13 tsunami events between the year 1861 and 2014. Based on data availability, five tsunami events, namely the 1977 Sumba, the 2004 Indian Ocean, the 2006 Java, the 2010 Mentawai, and the 2011 Great East Japan, were selected. Numbers of deaths and damaged buildings were used in combination with hazard data to estimate vulnerability, defined as the ratio between maximum flow depth against death and building damage ratios. Numbers of evacuees were initially used to estimate actual numbers of exposed population but it was later discovered that this parameter overestimated the exposed population in certain cases. As a result, this study presents the vulnerability characteristics of people and buildings in Indonesia, exposed to unusual or extreme tsunamis, mostly in a condition without or with limited access to official warnings. In brief, a maximum flow depth of 5 m caused an approximate 100% death ratio in the majority of Indonesian tsunamis in this study. On the other hand, death ratio in the 2011 Japan tsunami was limited to 10% because of the early warning and high disaster awareness. Effective disaster risk reduction activities such as official warnings, evacuations, and tsunami education were observed for certain locations. Lastly, adding hazard and population data at the village level is recommended for improving the collection of future tsunami disaster data for the GCDS database.

Description: An X-band radar was installed in 2014 at Merapi Museum, Yogyakarta, Indonesia, to monitor pyroclastic and rainfall events around Mt. Merapi. This research aims to perform a reliability analysis of the point extracted rainfall data from the aforementioned newly installed radar to improve the performance of the warning system in the future. The radar data was compared with the monitored rain gauge data from Balai Sabo and the IMERG satellite data from NASA and JAXA (The Integrated Multi-satellitE Retrievals for GPM), which had not been done before. All of the rainfall data was compared on an hourly interval. The comparisons were conducted based on 11 locations that correspond to the ground rainfall measurement stations. The locations of the rain gauges are spread around Mt. Merapi area. The point rainfall information was extracted from the radar data grid and the satellite data grid, which were compared with the rain gauge data. The data were then calibrated and adjusted up to the optimum state. Based on January 2017–March 2018 data, it was obtained that the optimum state has a NSF value of 0.41 and R2value of 0.56. As a result, it was determined that the radar can capture around 79% of the hourly rainfall occurrence around Mt. Merapi area during the chosen calibration period, in comparison with the rain gauge data. The radar was also able to capture nearby 40–50% of the heavy rainfall events that pose risks of lahar. In contrast, the radar data performance in detecting drizzling and light rain types were quite precise (55% of cases), although the satellite data could detect slightly better (60% of cases). These results indicate that the radar sensitivity in detecting the extreme rainfall events must receive higher priority in future developments, especially for applications to the existing Mt. Merapi lahar early warning systems.

Description: Watermelons(Citrullus lanatus)are known to have sufficient amino acid content. In this study, watermelons grown and consumed in Malaysia were investigated for their amino acid content, L-citrulline and L-arginine, by the isocratic RP-HPLC method. Flesh and rind watermelons were juiced, and freeze-dried samples were used for separation and quantification of L-citrulline and L-arginine. Three different mobile phases, 0.7% H3P04, 0.1% H3P04, and 0.7% H3P04 : ACN (90 : 10), were tested on two different columns using Zorbax Eclipse XDB-C18and Gemini C18with a flow rate of 0.5 mL/min and a detection wavelength at 195 nm. Efficient separation with reproducible resolution of L-citrulline and L-arginine was achieved using 0.1% H3P04on the Gemini C18column. The method was validated and good linearity of L-citrulline and L-arginine was obtained withR2= 0.9956,y=0.1664x+2.4142andR2=0.9912,y=0.4100x+3.4850, respectively. L-citrulline content showed the highest concentration in red watermelon of flesh and rind juice extract (43.81 mg/g and 45.02 mg/g), whereas L-arginine concentration was lower than L-citrulline, ranging from 3.39 to 11.14 mg/g. The isocratic RP-HPLC method with 0.1% H3P04on the Gemini C18column proved to be efficient for separation and quantification of L-citrulline and L-arginine in watermelons.

Description: Bricks of low elastic modulus are occasionally used in some developing countries, such as Indonesia and India. Most of the previous research efforts focused on masonry structures built with bricks of considerably high elastic modulus. The objective of this study is to quantify the equivalent elastic modulus of lower-stiffness masonry structures, when the mortar has a higher modulus of elasticity than the bricks, by employing finite element (FE) simulations and adopting the homogenization technique. The reported numerical simulations adopted the two-dimensional representative volume elements (RVEs) using quadrilateral elements with four nodes. The equivalent elastic moduli of composite elements with various bricks and mortar were quantified. The numerically estimated equivalent elastic moduli from the FE simulations were verified using previously established test data. Hence, a new simplified formula for the calculation of the equivalent modulus of elasticity of such masonry structures is proposed in the present study.