Undergraduate Theses
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Item Geochemical association of Cr, Cu, Ni, and Pb in the sediments of Iloilo River estuaryArban, John Paul B. (Division of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Visayas, 2005-04)The geochemical association of Cr, Cu, Ni, and Pb in the sediments of Iloilo River Estuary has been studied using a modified Tessier’s sequential extraction procedure. The results obtained show that most of the metals studied are mostly associated in the residual and organic matter fractions of the sediment samples (Cr: 66.26% - 74.36% in the residual,15.43% - 24.08% in the Fe-Mn oxide fraction, 8.14% - 12.71% in organic matter fraction, and 0.000% - 2.996% in the exchangeable/carbonate fraction; Cu: 39.30% - 46.73% in the residual, 12.00% - 52.18% in the organic fraction, 3.227% - 11.41% in the Fe-Mn fraction, and 0.000% - 17.43% in the exchangeable/carbonate fractions; Ni: 42.75% - 57.02% in the organic matter fraction, 24.93% - 39.33% in the residual, 5.814% - 14.15% in the Fe-Mn fraction, and 5.504% - 13.12% exchangeable/carbonate fraction; and Pb in sample AAA-21: 48.02% in the residual, 38.55% in the organic matter fraction, and 7.33% in the Fe-Mn fraction, and 6.078% in the exchangeable/carbonate fraction). The analysis of the total metal concentrations of the sediment samples taken from Iloilo River are found to be above the reported concentration of uncontaminated sediment except for Pb in sediment sample AAA-21 (Chromium: 102.1 ug/g - 150.5 pg/g; Copper: 62.56 pg/g - 111.7 pg/g; Nickel: 53.40 pg/g - 75.44 pg/g; and Lead in sample AAA-21: 22.21 pg/g). The study shows that about 50% of the total metal concentration in the sediment samples are bioavailable to the aquatic organisms.Item Chromatographic analysis and antibacterial assay of Avicennia officinalis bark extractsJanagap, Steve P. (Division of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Visayas, 2003-04)In this study, the antibacterial activity and the chemical constituents of Avicennia officinalis bark were determined. The antibacterial assay showed that the dichloromethane (DCM) fraction at 1000 ug/mL was most effective against the tested bacteria especially to Staphylococcus aureus. It had a microbial index of 0.97 while the positive control, amoxicillin had 1.00. The aqueous fraction did not show antibacterial activity to the organisms tested. A number of chemical constituents were found to be present in the different fractions obtained from Avicennia officinalis bark: alkaloids, cardiac glycosides, flavonoids, phenolic compounds, saponins and terpenes. These constituents were determined using thin layer chromatography. The DCM fraction which showed the highest bioactivity, had the most number of components while the aqueous fraction had the least number of components. The DCM fraction was subjected to two-dimensional thin layer chromatography. Nine spots were observed with the first solvent system (ethyl acetate-DCM; 5:3) while eleven spots were observed with the second solvent system (ethyl acetate-n-hexane-DCM; 2:1:1).Item Proximate analysis and fatty acid profile of Hyopila rosea Williams and Vesicularia reticulataAnuevo, Gwen M. (Division of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Visayas, 2000-07)Philippine mosses number about 506 species. Hyophila rosea Williams and Vesicularia reticulata are the two species that are found abundantly in Panay area. Hyophila rosea Williams are medium-sized plants in thin clusters with stems from 1-1.5 cm high. Proximately characterized to contain 17.82% moisture, 5.99% crude protein, 7.69% crude ether extract, 21.42% crude fiber, 18.21% ash, and 46.69% nitrogen-free extract. Fatty acid profiles are composed of twenty-nine (29) analytes, from which twenty (20) were not identified while nine (9) are known, starting from Caproic acid (C1o) to Arachidic (C20). Linoleic, palmitic, and oleic acids are the first three analytes comprising higher percentages. Vesicularia reticulata, on the other hand, are dull, yellowish green, and the main stem is about 5 cm long. Proximately characterized to contain 12.73% moisture, 5.96% crude protein, 9.45% crude ether extract, 21.95% crude fiber, 32.67% ash, and 29.96% nitrogen-free extract. Fatty acid profiles are composed of forty-one (41) analytes, from which thirty-two (32) analytes were not identified, while nine (9) analytes are known starting from C1o to C2o.Linoleic, palmitic and linolenic acids are the first three analytes comprising higher percentages.Item Toyang Ermitanya and the consumption of Iloilo City proper-based listeners vis a vis Miagao-based listenersAbenes, Darren Al B.; Concepcion, Ma. Emilee Anne R.; Paren, Ryan M. (Division of Social Sciences , College of Arts and Sciences, University of the Philippines Visayas, 2008-10)This study sought to study the following: 1) the consumption of listeners from the two groups of respondents from the urban community which is Iloilo City Proper vis a vis the rural community of Miagao, and 2) the way the listeners perceive such radio drama whether as something which convey issues in the society or as something which is purely entertaining. The researchers used two major steps in data gathering: survey and indepth interviews. One hundred respondents who were listeners of such drama participated, half of which came from both groups of respondents who were Iloilo City Proper-based and Miagao-based. The survey revealed that Iloilo City Proper-based respondents have a higher frequency of exposure to such drama compared Miagao-based respondents. It was also revealed that majority of the respondents from each group of respondents perceived Toyang Ermitanya as entertaining however, majority also claimed that they were also learning lessons and insights from it. Moreover, with the results and data collected and analyzed, the research itself revealed three prevailing forms in the consumption of such radio drama by both groups of listeners. First, Toyang Ermitanya as a medium for emotional release. Second, as a form of enjoyment. And third, Toyang Ermitanya as a medium where one could obtain pieces of information and advice from listening to it.Item Fecundity and egg quality in two species of siganids (Siganus canaliculatus and Siganus fuscescens) from Lanuza Bay, Surigao del Sur, PhilippinesAnore, Gaguis Anito II T. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2019-06)Siganus canaliculatus and Siganus fuscescens are two of the important yet highly exploited siganid aquatic resources in the Philippines. Only few studies for both species, especially for S. fuscescens, are available in the Philippine setting regarding its fecundity and egg quality. This study was conducted to provide information on the fecundity and egg quality of S. canaliculatus and S. fuscescens from Lanuza Bay, Surigao del Sur, Philippines. Fecundity was determined through gravimetric method in individual gonads. Fecundity range was determined to be 54,856 — 279,957 individual oocytes for S. canaliculatus and 7,397 — 563,722 for S. fuscescens. Fecundities of both species exhibited a weak to strong positive correlation to size, with higher correlation coefficient to standard length for S. canaliculatus and body weight for S. fuscescens. On the other hand, egg quality was determined through mean oocyte diameter, with diameters ranging from 176 — 426 ųm for S. canaliculatus and 171 — 500 pm for S. fuscescens. Mean oocyte diameters of both species exhibited weak positive correlation to size, but with a higher correlation coefficient on standard length. Regulating the capture of smaller-sized fishes and allowing them to grow would promote the increase in fecundity and egg quality of the species.Item Optimization of pH, sorbent dose, and contact time in biosorption of Cu, Cd and Pb in sugarcane bagasse in a tri-metal aqueous systemAbetria, Pauline Grace R. (Department of Chemistry, College of Arts and Sciences, Univsersity of the Philippines Visayas, 2013-04)Adsorption is one of the physicochemical treatment processes found to be effective in removing heavy metals from aqueous solutions. The biosorption of Cu, Cd, and Pb in sugarcane bagasse in a tri-metal aqueous system was optimized for pH, sorbent dose, and contact time using Doehlert design and it was found that the optimal values are pH 5, a sorbent dose of 1.33g sorbent/mg metal, a contact time of 4 hours, and the available sites on the sorbent for metal binding were influenced by pH. Furthermore, the effect of initial metal concentration on the metal uptake of the sorbent was also studied and it was found that at increasing metal concentrations the metal uptake also increased at a fixed (optimum) sorbent dose. The sorbent affinity was observed to be increasing in favor of increasing ionic radius, Cu < Cd < Pb, at relatively low metal concentrations and Cd < Cu < Pb at relatively high metal concentrations. Each metal behaved differently on the sorbent. Copper obeyed the Langmuir isotherm whereas cadmium and lead both obeyed the Freundlich isotherm. Finally, the IR spectrum of the sorbent was elucidated and -OH and -COOH groups were present but complexation was absent. Hence, in a tri-metal aqueous system containing Cu, Cd and Pb, the biosorption process in bagasse is proposed to be by physical adsorption.Item Determination of the anthocyanin content in Hibiscus sabdariffa L. (Roselle) calyses from fresh to spray-dried formArganioza, Hannah Mae C. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2015-06)Hibiscus sabdariffa L. is an agricultural herb with calyces as the commercially important part this plant. The calyces is a good source of anthocyanin (pigments) with several potential applications in the food, pharmaceutical and cosmetic industries. These pigments are used worldwide in the production of drinks and as a source of natural food coloring. However, these pigments are very unstable due to processing and storage conditions. Thus, this present study investigated the amount of anthocyanin as it is processed into a commercial product in the form of spray-dried powder. The Roselle plant samples were obtained from Herbanext Laboratories farm. The fresh extract has 493.45 mg/L total monomeric anthocyanin. Compared to the fresh extract, concentrated aqueous spray-dried extract (261.06 mg/L) contains lower anthocyanin content, however, this is significantly higher than aqueous concentrate (124.41 mg/L). Both the aqueous extract and ethanolic extract contains the smallest amount of anthocyanin for each sets. Spray drying techniques increases the amount of anthocyanin which helps to prevent further degradation of the compound due to the influences of the storage environment and processing conditions.Item Optimization of extraction Conditions of water-soluble phenolics from tawa-tawa (Euphorbia hirta L.) based on Densitometric TLC using gallic acid as marker compoundAborka, 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.Item A survey of the catch composition of fyke nets in the Iloilo riverAndrada, Kristina Abelaine D. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2000-04)A survey of the catch composition of fyke nets in the Iloilo River Estuary during the months of August 1999 and February 2000 show that catches are dominated by Metapenaens crisis and (ilossygobius sp. The 18 species caught are : 9 fish species, 5 shrimp species, and 4 crab species. The index of similarity 0.3 between the monthly samples is low which means that there is minimal degree of similarity between the species composition of the catches. There is no significant difference between the total catch volumes per day for the months of August 1999 and February 2000 which means that the seasons do not affect the volume of the catch.Item Optimization of lead (II) adsorption of EDTA-functionalized magnetic graphene oxide using response surface methodologyAngeles, Christine Debbie Shanne V. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2017-06)Chronic intake of lead-contaminated water, even at low concentrations, can cause damage to the digestive, reproductive, and nervous systems. To effectively remove lead in water, solid phase extraction or adsorption is being used. In this study, EDTA-functionalized magnetic graphene oxide (EmGO) adsorbent was fabricated using a stepwise modification of graphene oxide (GO). It was characterized using SEM, FTIR, and XRD. EmGO was shown to have improved adsorption capacity towards Pb(II) in natural water. Also, the magnetic property of the adsorbent allowed an easier and more convenient mean of retrieval. The generated response surface model from Box- Behnken design (BBD) approximated the optimum condition for maximum removal efficiency of EmGO. Based on the results, the model had a 0.9113 (±0.0001) overall desirability, optimum values for pH, adsorbent dosage, and contact time were 5.99 (±0.01), 12.2135 (±0.0001), and 48.39 (±0.01), respectively. The highest percent removal efficiency of EmGO in the experiment was determined to be 73.41 (±0.01)%.