Flash-flood hazard hydro-geomorphic characterization and mapping: analysis of the 2019 and 1994 Francolí river flood effects.

<p>On October 22, 2019, intense rains took place in Catalonia (292,6 mm in 24 hours at Prades), associated with a meteorological isolated depression at high atmospheric level (DANA in Spanish language). These rains caused a sudden discharge increase and a major flash-flood in the Francolí river (Tarragona, Catalonia, Spain). As a result, the river swept along a large quantity of vegetation, crops and infrastructures, such as bridges, roads, and houses. Unfortunately, the flood caused a considerable economic damage (exceeding 100 million euros), and a loss of six human lives. This area was also affected by the 1994 flood, which produced 10 fatalities and losses worth 17,000 million euros.</p><p>The Francolí river watershed has an area of 853 km<sup>2</sup> and a length of 59 km. The study area stretches for ~20 km along the upper basin, without regulatory infrastructures. It covers the localities of Vimbodí, L´Espluga de Francolí, Montblanc and Vilaverd, with a population of 12,463 people. Downstream Vilaverd, the river crosses the strait of La Riba at the west of the Prades mountains. The Francolí River has low water levels much of the year and a strong seasonal regime. It presents high sediment mobility and large transportation capacity.</p><p>Orthophotographs, LiDAR and field work data, including GNSS-RTK data of river sections, are fundamental for this hydro-geomorphic analysis. It is performed mostly through classical and stereo-anaglyph photo-interpretation and comparison of the 2019 (post-flood event), 2016 (pre-flood event), 1995 (after the 1994 flood) and 1945-56 orthophotographs (provided by the Geological and Cartographic Institute of Catalonia). The main effects considered are: a) channel migration, cuts or changes in the sinuosity of meanders; b) significant bank erosion; c) pull up and dragging of vegetation; d) channel widening and braiding; e) development of secondary active channels during the flood; f) significant erosive and sedimentary morphologies; g) extension of the flooded areas through ephemeral evidence. From the geomorphological effects of the 2019 and 1994 floods, the Active Band is determined and mapped. This characterization highlights that the Francolí river is, geomorphologically, very active. In consequence, when defining flood hazard zones, hydraulic modelling would not be able to capture the complexity of this system and would produce biased results.</p><p>Once the Active Band is determined and with the estimation of peak flows in crucial localities, the Preferential Flow Zone (PFZ) can be defined. PFZ is the envelope of the areas where the flow concentrates during major floods or, also, the most frequently flooded areas in minor floods. This zoning allows us to discriminate areas with high and low flow energies, and to identify the margins most prone to erosion. Accordingly, varying levels of flood hazard can be mapped, and flood areas classified.</p><p>This combined analysis of indicators allows us to characterize the flood hazard more precisely in the studied stretch. The method can serve to better understand and predict the flash-floods associated hydro-geomorphic hazards in these kind of geomorphologically active rivers.</p><p>The authors thank the financial support from PROMONTEC project (CGL2017-84720-R AEI/FEDER, UE), Spanish MINEICO.</p>

Tunable Active Band-Pass RC-Filter

This article provides a technique for design and simulation of an active second order band-pass filter with lineal tuning of Q-factor and independent tuning over a wide range of resonant frequency and transfer coefficient. The tunable band-pass RC-filter is required for selective processing of electric signals in radio engineering systems and devices, as well as in in-formation measuring systems, the acoustic and hydro acoustic equipment, including devices for noise and vibration analysis. The band-pass RC-filter is required in equalizers for allocation of useful signals.It is shown that the filter is constructed on the basis of the active second order correcting link with the use of tunable RCcircuit T-bridge. Calculation formulas for filter parameters are received, i.e. resonant frequency, polar Q-factor and transfer coefficient. It is shown that in the filter circuit these parameters can independently be tunable over a wide range. Resonant frequency of the filter is tuned by means of dual variable resistors with the Q-factor and transfer coefficient remaining constant.Polar Q-factor is regulated by change of resistance of the variable resistor with transfer coefficient and resonant frequency remaining constant. The transfer coefficient changes by means of another variable resistor.The conclusions of expressions for the tuned parameters of the suggested circuit of the active band-pass RC-filter confirming the research are provided, as well as the filter frequency characteristics and tunable parameter diagrams. Filter implementation is supported by simulation with the use of MicroCap10 software.

Exploration of Mango Fruits (Mangifera indica) as α-Glucosidase Inhibitors

<p class="IsiAbstrakIndo"><span lang="EN-GB">Mango fruit (</span><em><span lang="EN-GB">Mangifera indica L.</span></em><span lang="EN-GB">) is the tropical fruit that grows easily in Indonesia with plenty varieties. This study aimed to determine the varieties of mango fruit and the most potent part of mango as antidiabetic agent through </span><span lang="EN-GB">α</span><span lang="EN-GB">-glucosidase inhibitory activities. Four types of mango fruit (</span><em><span lang="EN-GB">indramayu, manalagi, harum manis</span></em><span lang="EN-GB">, and </span><em><span lang="EN-GB">budiraja</span></em><span lang="EN-GB">) were used in this study. Each part of the mango fruit:peel, flesh, endosperm, and endocarp were extracted by maceration process with three different solvents (n-hexane, ethyl acetate (EtOAc), and ethanol (EtOH)). An ability of all 46 extracts in inhibiting the </span><span lang="EN-GB">α</span><span lang="EN-GB">-glucosidase at a concentration of 500 ppm were determined. Then 11 extracts with the high inhibition value were determined their IC50 (concentration to inhibit 50% activity) values. EtOAc extract of </span><em><span lang="EN-GB">manalagi</span></em><span lang="EN-GB">, </span><em><span lang="EN-GB">indramayu</span></em><span lang="EN-GB">, and </span><em><span lang="EN-GB">budi raja</span></em><span lang="EN-GB"> endosperm had the lowest IC50 value which was not statistically significantly different (at 95%) with EtOAc extract of </span><em><span lang="EN-GB">budi raja</span></em><span lang="EN-GB"> peel. The bioautographic Thin Layer Chromatogram showed that the most active band is characterized by white luminescence under UV 366 nm, yellow color under UV 254 and visible light. The band with Rf 0.93 from EtOAc endosperm extract of </span><em><span lang="EN-GB">indramayu</span></em><span lang="EN-GB"> and </span><em><span lang="EN-GB">manalagi</span></em><span lang="EN-GB"> and Rf 0.73 from EtOAc </span><em><span lang="EN-GB">budi raja</span></em><span lang="EN-GB"> peel extract are the most active band which predicted as a flavonoid. The result adds the value of the peel and seed of mango, as well as an alternative in blood sugar control, which is easy to obtain, relatively cheap, and liked by the community. </span></p>