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UPV Theses and Dissertations

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Committee Chair: search.filters.chair.Janagap, Steve P.SDG: search.filters.sdg.SDG 6 - Clean water and sanitation

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    Physico-chemical assessment of the groundwater in Barangay Mohon, Arevalo District, Iloilo City
    Adenix, Kimberly V. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2017-06)
    Water analysis determines the stability and reliability of natural water sources. Determining the physical and chemical compositions of water would indicate its safety for use and consumption. In this scientific study, water analysis was conducted to evaluate the quality of potable water from eight water pumps, commonly used for drinking, in Brgy. Mohon, Arevalo District, Iloilo City. Aside from drinking, most residents also used these groundwater sources for cooking, bathing, washing, and laundry purposes. The parameters tested were pH, temperature, alkalinity, phosphate, nitrite, dissolved oxygen, and heavy metals (e.g., lead, copper, and cadmium) content. The analyses were conducted from February to April with same time of collection (9:00 am-12:00 nn) and the samples were stored under dark and cold conditions (4 °C). During the analyses, the following methods were used: titrimetric for alkalinity and dissolved oxygen content, colorimetric and UV/Vis spectrophotometry for phosphate and nitrite-nitrogen, and atomic absorption spectroscopy (AAS) for heavy metals. Results showed that all sampling sites were determined to have alkaline waters (7.29- 7.77), because of the high pH and alkalinity values. Also, it was found that the water sources contained very high phosphate levels (0.54-1.29 mg/L PO4-P) that contributed to very low DO levels (0.12-0.14 mg/L DO). Other parameters, such as nitrite-nitrogen and heavy metal determinations showed no significant difference based on the standard limits set by different environmental institutions.
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    Antibacterial agent-loaded water-in-oil-water (W/O/W) emulsion
    Aguilar, Ma. Arianne Lou C. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2018-06)
    In this study, a water-in-oil-in-water (W/O/W) emulsion incorporated with an antibacterial agent using polyglycerol polyricinoleate (PGPR), whey protein isolate (WPI) and lecithin as emulsifying agents under ultrasonication was prepared. Micrographs of the emulsions formed showed small droplet sizes with an average range of 0.07 — 8.7 μm which indicates that the emulsification process was effective. However, the emulsion was only stable for 7 days. Natural and synthetic antibacterial agents were then loaded into the W/O/W emulsion. A solution of chlorhexidine gluconate (CHG) was chosen as the synthetic antibacterial agent to be loaded into the W/O/W emulsion because of its established stability and antibacterial efficacy against Gram—positive and Gram—negative bacteria. On the other hand, Psidium guajava (guava) was chosen as the natural antibacterial agent to be loaded because of its abundance and folkloric use to treat wounds. The CHG—loaded emulsion showed a mean zone of inhibition equal to 11.3 ± 2.1 mm against Staphylococcus aureus and 12.0 ±1.0 mm against Escherichia coli. The Psidium guajava (guava) — loaded emulsion on the other hand showed no inhibitory activity which suggests that the bioactive component of the guava may have been destroyed during sonication process. The results of this study showed that a synthetic antibacterial agent loaded - W/O/W emulsion was more effective than the natural antibacterial agent loaded — W/O/W emulsion.
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    Optimization of extraction Conditions of water-soluble phenolics from tawa-tawa (Euphorbia hirta L.) based on Densitometric TLC using gallic acid as marker compound
    Aborka, Ma. Ayanne B. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2015-06)
    The present study aimed to optimize the extraction conditions of water-soluble phenolics for tawa-tawa (Euphorbia hirta L.) with gallic acid as the compound of interest. Water was used as extraction solvent. The effect of the interactions of different extraction temperature (50°C, 60°C and 70°C) and extraction time (20 min, 40 min and 60 min) were investigated. To evaluate the importance of the parameters on the extraction efficiency of gallic acid, a factorial design was used. The normal probability plot and estimates of standard error showed that time and temperature were both significant parameters. It further showed that time was a more significant contributor than temperature to the extraction efficiency of gallic acid. The results revealed that interaction of time and temperature did not have significant effects. The ANOVA results showed that only extraction parameter with significant effect was time (p < 0.05). Temperature and its interaction with time did not have significant effects. Based on the desirability values generated by Design-Expert 9.0.4, the optimal conditions in extracting gallic acid were the following: extraction time of 60 minutes and extraction temperature of 70°C. Results of FTIR analysis confirmed the presence of the following functional groups: O-H, C=O, C-O, C-H (aromatic), C=C (benzene) and out-of-plane bending or oops. Gallic acid in tawa-tawa is present in esterified form and exists as part of hydrolysable tannins.