In this paper, a low cost, real-time water quality monitoring system which can be applied in remote rivers, lakes, coastal areas and other water bodies is presented. The main hardware of the system consists of off-the-shelf electrochemical sensors, a microcontroller, a wireless communication system and the customized buoy. It detects water temperature, dissolved oxygen and pH in a pre-programmed time interval. The developed prototype disseminates the gathered information in graphical and tabular formats through a customized web-based portal and preregistered mobile phones to better serve relevant end-users. To check the system effectivity, the buoy's stability in harsh environmental conditions, system energy consumption, data transmission efficiency and webbased display of information were carefully evaluated. The experimental results prove that the system has great prospect and can be practically used for environmental monitoring by providing stakeholders with relevant and timely information for sound decision making.

Mango seed kernel, a by-product of the processing industry, can be valorized as a potential source of bioactive compounds. Binary mixtures of ethanol and water, used in solid-liquid extraction (SLE), have drawn interest as an effective means of recovering phytochemicals from plant materials because these solvents can be used in food applications and their synergistic effect makes them a superior solvent over their pure counterparts. Total phenolic content (TPC) and HPLC chromatograms of each ethanolic extract revealed that ethanol concentration had a significant effect on phenolic compound recovery, wherein, TPC of mango kernel varied from 18.19 to 101.68 mg gallic acid equivalence (GAE) per gram of sample. Subsequently, the antioxidant activities (AOAc) of the extracts, measured by scavenging activities with the DPPH ? (1,1diphenyl-2-picrylhydrazyl) radical and ferric reducing antioxidant power (FRAP) assay, ranged from 8.19 to 85.45 mmol/L and 3.82-55.61 mmol/L Trolox equivalence, respectively. The solvent containing 50% (w/w) ethanol-water had the highest TPC and exhibited the most potent reducing and radical scavenging activities. With the use of an HPLC-UV/Vis, gallic acid, caffeic acid, rutin and penta-O-galloyl-b-D-glucose were identified to be present in the mango seed kernel. Results show that the mango seed kernel is a viable source of bioactive compounds which can be recovered with water-ethanol binary solvent systems.

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This article investigates changes in travel behavior from selected urban cities in Metro Cebu, Philippines during the COVID-19 pandemic a year after the first lockdown. Different categories of community quarantine and granular lockdowns have since been imposed to curb the spread of the virus. An online survey was distributed to analyze socio-demographic characteristics and reasons for traveling in relation to weekly trip frequency before and during pandemic. These are presented and analyzed through data visualization and multinomial logistic regression. Results show that the major reason for traveling before pandemic was work-related but has since shifted to buying essentials or for leisure or recreation. Weekly trip frequencies were lesser when compared before pandemic, but several socio-demographic groups have shown otherwise. There is statistical significance for those less likely to travel when commuters are employed, self-employed or students compared to unemployed, earning PHP 10,000 or less compared to those earning above PHP 50,000, in a household size of 10 compared to all other household sizes, and those with college degree against elementary or no formal education. By determining the travel behavior of commuters when they have ample time to adjust to the new normal, their mobility needs can be best understood and consequently satisfied. Interventions in fulfilling the travel needs for those belonging to socio-demographic groups that are highly affected by the pandemic, such as the working class, blue-collar workers, and have limited financial capabilities, can also be developed when a similar outbreak in the future is imminent.

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This study implements remote sensing (RS) and geographic information system techniques in deriving physical and spectral characteristics of a catchment to aid in water quality monitoring. This approach is conducted by utilizing RS datasets like digital elevation model (DEM), satellite images, and on-site spectral measurements. A Shuttle Radar Topography Mission DEM was used for extracting physical profiles while Landsat Operational Land Imager was utilized to extract land cover information. This method was tested in a 22,000-ha catchment with dominant agricultural lands where large-scale mining companies are also operating actively. The land cover classification has an overall accuracy of 97.66%. Forest (50%) and cropland (32%) are the most dominant land cover within the catchment. The spectral signature of waters at designated sampling points was measured to evaluate its correlation to water quality data like pH and dissolved oxygen (DO). The correlation between the level of pH and reflectance implies a positive relationship (R 2 of 0.548) while that of DO and reflectance gives a negative correlation (R 2 of 0. 634). Results of this study demonstrate the practical advantage of exploiting remotely-sensed data in profiling and characterizing a catchment as it provides valuable information in understanding and mitigating contamination in an area. Through these RS-derived catchment profiles, insights on the contaminant's concentration and possible sources can be identified. The graphical and statistical analysis of the spectral data prove its potential in developing water quality models and maps.

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