Abstract

In this paper, we initiate the study of trigeneralized topological spaces. More particularly, we investigate some types of continuous functions defined between trigeneralized topological spaces.

Index Terms

trigeneralized topological space, closed set, open set, continuous function

Abstract

A fully sequential procedure is considered in the point estimation of the powers of the ratio of two exponential scale parameters. Formulation of the stopping rule is developed with the aim of minimizing the risk involved in the estimation of the parameter . Results of this paper show that the sampling scheme developed will eventually stop. In addition, first-order properties of the proposed sequential procedure are derived and simulations using Scilab are provided to give illustration of the performance of the proposed procedure.

Index Terms

Exponential, sequential, SciLab

Abstract

The study establishes the toxicities, antioxidant properties and antimicrobial activities of the hexane (LcH), chloroform (LcC) and aqueous (LcA) fractions of the ethanol extract of Leucosyke capitellata leaves. Assessment of the toxicity of the fractions of L.capitellata done using the brine shrimp lethality test showed that all fractions were considered inactive since not one of the fractions was able to kill half of the population of the brine shrimp. Meanwhile, amont the three fraction, the LcA fraction consistently exhibited the highest antioxidant properties: radical-scavenging activity 75.28 % at 500 ppm, a total antioxidant capacity of 77.94 ascorbic acid equivalents (AAE) and 84.31 butylated hydroxytoluene equivalence (BHTE) and a total phenolics content value of 92.87 mg gallic acid/ g sample. The antimicrobial assay showed that fractions LcA and LcC exhibited partial antibacterial activity against B. subtilis and S. aureus, respectively. For the antifungal activities, both fractions LcH and LcA were active against C. albicans.

Index Terms

Leucosyke capitellata, toxicity, antioxidant,

antimicrobial, antiradical activity, total phenolics

Abstract

Crude ethanol extract and chlorofom-soluble extract and its fractions of the aerial parts of Cyperus brevifolius Rottb. were in vitro investigated against Eudrilus eugeniae earthworms. To obtain crude ethanol extract, chloroform-soluble and its fractions, serial solvent extraction and gravity column chromatography with thin-layer chromatography were employed, respectively. From the results obtained, chloroform-soluble extract showed noteworthy anthelmintic activity relative to crude ethanol extract as exhibited by faster mean time of paralysis and death of the test organisms in all prepared concentrations. Meanwhile, of the three fractions of chloroform-soluble extract, only one fraction (coded CBC5) showed better anthelmintic activity than the mother extract. Furthermore, CBC5 results are comparable and better than the positive control mebendazole.

Index Terms

anthelmintic activity, helminthiases, Cyperus

brevifolius Rottb., Eudrilus eugeniae

Abstract

The bioactivities and potential medicinal properties of the leaves of Derris elliptica Benth were investigated by evaluating the toxicity, antioxidant and antimicrobial activities of its hexane (DeH), chloroform (DeC) and aqueous (DeA) fractions. Results show that the DeA fraction exhibited chronic toxicity against the brine shrimp A. salina Leach with an LC50 = 501 ppm which indicates that the fraction is active. The DeC fraction was shown to have the highest antioxidant potentials in terms of total antioxidant activity and total phenolics content. In terms of radical-scavenging activity, both DeC and DeA exhibited similar activities. The toxicity and antioxidant assay results also demonstrated that the DeC fraction exhibited antioxidant activities but it was not toxic. For antimicrobial activities, DeH, DeC and DeA fractions were partially active towards S. aureus, A. niger and B. subtilis Furthermore, DeA fraction was very active against S. aureus.

Index Terms

Derris elliptica, toxicity, total antioxidant, radical

scavenging activity, total phenolics, antimicrobial

Abstract

The present study was designed to evaluate the phytochemicals, cytotoxicity and antioxidant activities of Nypa fruticans extracts. Phytochemical screening revealed the presence of flavonoids (23.61%), alkaloids (2.64%), phlobatannins, saponins, and steroids. The ethyl acetate extract at 1000 ppm showed bioactivity (92% mortality) against nauplii Artemia salina. The extracts showed no inhibition against B. subtilis and E. coli. Furthermore, the antioxidant activity of the extracts were tested by its ability to reduce Mo (VI) to Mo (V) through subsequent formation of green phosphate Mo(V)-complex at acidic pH and positive results were observed in ethyl acetate extracts and fractions as indicated by their ascorbic acid equivalents.

Index Terms

antioxidant, antibacterial, cytotoxic, phytochemicals, Nypa fruticans

Abstract

Two medicinal flavone aglycones, the widespread ACACETIN and the non-widespread DIOSMETIN, were earlier reported as having been isolated from the dichloromethane fraction of the leaves of Premna odorata Blanco (Lamiaceae), a native tree of the Philippines and locally known as “alagaw”. This current study reports on the investigation on the hexane fraction. By MS and NMR analyses, several saturated fatty acids were determined to be present in the hexane fraction of the leaves of P. odorata.

Index Terms

Premna odorata Blanco (Lamiaceae), alagaw,

diosmetin, acacetin, saturated fatty acids

Abstract

Boron, in the form of borates and boric acid, is a substance with a much checkered history in terms of its being beneficial element to humankind due to its ability to preserve foods without any apparent harmful effect to human health. However, after sometime, reports from the results of studies that started in the 1980s revealed that boron is beneficial to plants and animals but might be a factor to some human disorders. Boron might be a factor in some human disorders such as disturbed macromineral metabolism, e.g., osteoporosis. When present in excess amounts e body, it may pose adverse effects to health such as illness in the stomach, kidney, liver and etc. Previous studies showed that most instant foods like fish balls, noodles contain different levels of boric acid among factories and production periods due to the lack of the standard measurement during the processing. The mean boric acid content of representative samples of four brands (coded) of instant noodles commonly available in local grocery stores was assessed by spectroscopic method. The results were: brand A= 35.67 mg/kg; B = 36.98 mg/kg; C = 33.12 mg/kg; D = 172.16 mg/kg. The values exceeded the allowed daily intake (ADI) value set by the European Food Safety Authority (EFSA) which is 10 mg/per day.

Abstract

This work investigated the bioactivities of the hexane (IcH), chloroform (IcC) and aqueous (IcA) fractions obtained by sequential partitioning of the ethanolic leaf extract of the plant Ixora chinensis. The fractions were evaluated for toxicity using the Brine Shrimp Lethality Test (BSLT) against Artemia salina Leach; for antioxidant porperty using DPPH- radical scavenging test, total antioxidant activity by phosphomolybdenum method and total phenolics content by Folin- Ciocalteu method and for antimicrobial activities using the paper disc diffusion method. In the toxicity test, only the IcH fraction showed activity against A. salina Leach. In the antioxidant activity screening, all fractions exhibited low antiradical activities, fraction IcC showed the relative highest total antioxidant potential and fraction IcH demonstrated the highest total phenolics content. In the antimicrobial assay, IcC was active against A. niger and partially active towards C. albicans, IcA was partially active towards B. subtilis while IcH was inactive against all the test microorganisms.

Index Terms

Ixora chinensis, brine shrimp lethality test, DPPH radical assay, phosphomolybdenum method. Folin-Ciocalteu, antimicrobial

Abstract

The rising incidence on incessant agricultural pest’s infestation is still and will continue to be man’s problem. Such prevalence has long been causing hazards to food consumption and safety, detriments to health and environmental concerns. This occurrence has aroused scientists to continually search for alternatives to address the abovementioned issue. In the light of plant-based pesticide development, the present study was conducted to evaluate the insecticidal properties of the decoctions and crude ethanol extracts of three medicinal plants of folkloric value, namely: Annona squamosa Linn. (Atis), Jatropha curcas Linn. (Tuba-tuba) and Lantana camara Linn. (Baho-baho), against common agricultural pests, Sitophilus zeamais Motschulsky (maize weevil) and Tribolium castaneum Herbst. (Red-flour beetle). Contact bioassay method was employed at various concentrations in which the activity of the test samples was significantly correlated with contact time. Results showed fairly high mortality rates incurred in all test organisms used on crude ethanol extracts as compared to its decoction counterparts at the same concentration. Moreover, concentration-dependent toxicity relationship was also observed during the conduct of the bioassay on crude ethanol extracts. Generally, among all crude ethanol extracts used, Jatropha curcas L. (JCE) exhibited highest toxicity against maize weevil, while Lantana camara L. (LCE) exhibited highest toxicity against red-flour beetle. Thus, both JCE and LCE, among the plant samples, notably showed great potential of being botanical pesticides.

Index Terms

bioassay, insecticidal, Sitophilus zeamais, Tribolium castaneum

Abstract

Zinc sulphide (ZnS) nanostructures were grown using chemical bath deposition technique. Scanning electron microscopy - energy dispersive x-ray was used to characterize the surface morphology and composition; ultraviolet visible spectroscopy was used to approximate the band gap energy and two-probe method to determine the resistance of the grown ZnS nanostructures. Using these techniques, we have specified the effects of ZnCl2 concentration and heat treatment on the growth of ZnS. Denser and smaller nanostructures were grown at higher ZnCl2 concentration while thermal annealing triggers an increase in nanostructures size. The band gap energy decreased with increasing thermal annealing temperature. ZnCl2 concentration and thermal annealing greatly affected the morphological, optical and electrical properties of ZnS nanostructures.

Index Terms

thermal annealing, zinc sulphide, nanostructures, surface morphology and optical characteristics

Abstract

The design of minichannel heat exchangers has attracted lots of attention in its application to localized heating and cooling system for miniature devices. The purpose of this study is to compare the temperature profile, measure the pressure drop, to calculate the heat flux and the heat transfer coefficient of the three (3) minichannel copper blocks used as evaporator with R-134a as the refrigerant. Experiments were conducted using three evaporator specimens of different channel hydraulic diameters (1.0mm, 2.0mm, 3.0mm). The total length for each channel is 640.0mm. The dimension of each is 100mm.x50mm.x20mm. and the outside surfaces were machined to have fins. They were connected to a standard vapor compression refrigeration system. During each run of the experiment, the copper block evaporator was placed inside a small wind tunnel where controlled flow of air from a forced draft fan was introduced for the cooling process. The experimental set-up used data acquisition software and computer-aided simulation software was used to simulate the temperature profiles of the evaporator during the experimental run. The trend of the temperature distribution of R-134a inside the minichannel is increasing with 3mm minichannel resulted a high temperature drop inside the wind tunnel with an average of 4.45 Co. The pressure drop is highest for 1mm minichannel at 1.34 bar, 0.63 bar for 2mm minichannel and 0.29 bar for 1mm minichannel. The calculated heat flux for 3mm minichannel is 1414.31 kW/m2, for 2mm minichannel is 224.63 kW/m2 and for 1mm minichannel is 157.68 kW/m2. The heat transfer coefficients were calculated for 3mm at 7,688.95 kW/m2-K, 2mm at 205.73 kW/m2-K and for 1mm at 34.94 kW/m2-K.

Index Terms

minichannel heat exchanger; heat transfer coefficient; vapour compression cycle

Abstract

In a nationwide effort to provide long-term solution to Mindanao’s Power Crisis, there is a call for additional sources of energy. In order not to increase the country’s carbon footprints in effect, additional sources of energy in renewable forms are the most viable option. With Mindanao’s estimated hydropower potential of over 1,000 MW, identifying potential hydropower sites is the primary step towards harnessing these undeveloped potentials. However, in situ streamflow measurements for this purpose are costly, time-consuming, risky, and impractical when employed at a large scale. An alternative method of Flow estimation is employed in this study using remotely-sensed data and Geographic Information System (GIS) technology. Auto-delineation of watersheds and stream networks in Iligan are carried out with the use of a 10-m resolution Synthetic Aperture Radar – derived Digital Elevation Model, precipitation, landuse, hydrologic soils, and other datasets. GIS-based simulation and models provide a fast, scalable, practical, risk-free, and efficient estimation of Flow at any portion of the stream networks. Information derived from this study is useful to policy makers and concerned agencies involved in hydro resource management, planning and development.

Index Terms

Geographic Information System (GIS), Hydropower, Streamflow, Watershed delineation