Kola nuts are usually eaten fresh and represent a substantial source of income for many households and certain public authorities. Their importance lies in their content of some secondary metabolites of interest used in industries for the production of energy drinks and pharmaceuticals. The aim of this study is to reveal and determine the content of polyphenols (flavonoids in particular) and caffeine in nuts from Côte d’Ivoire. According to their phenotypical characteristics, four lots of nuts were collected (Red Cola nitida (RCN); White Cola nitida (WCN); Purple Cola nitida (PCN) and Garcinia kola (WGK)). After drying, different extractions were carried out using several solvents: water, acidified water (0.01N citric acid), methanol, ethanol, acetone 60% and methanol/acetic acid 1% solution. Phytochemical screening showed that kola nuts contain antioxidants such as flavonoids, tannins and alkaloids in varying proportions according to the species. Spectrophotometric analysis revealed that total polyphenols and flavonoids are important in C. nitida nuts compared to those of G. kola. Phenolic contents are 26.76±0.54; 23.08±1.06; 17.06±1.03 and 14.90±0.64 mg/g FW for WCN, RCN, PCN and WGK respectively. As for flavonoids, levels are 803.03±14.48, 697.13±12.76, 647.76±21.16 and 355.74±17.03 mg/kg FW for WCN, RCN, PCN and WGK respectively. It noted that acetone 60% is the efficient solvent for extraction. Statistical analyzes indicate the significant influence at P=.05 of solvent and nuts morphotype on the level of extractable for total polyphenols (P=.000000) and flavonoids (P=.000000) respectively. Concerning caffeine, reversed-phase HPLC analysis indicates that concentrations are higher in C. nitida extracts with a slight predominance for RCN (10812.5±6.27 mg/kg FW). We note a small amount of this metabolite (80.08 ±2.91 mg/kg) in G. kola. The mean intakes of nutrients are 3.99 and 1217.13 mg of polyphenol/day for an equivalent daily intake of 0.6 g (cola amount consumed per day in West Africa) and 183 g (amount of fruit consumed per day). About caffeine, intakes are 4.31 and 1313.05 mg/day for 0.6 and 183 g respectively. These findings indicate that kola seeds are enriched in important compound and can be used as a possible source of antioxidant for African population’s customs and European industries.
Cucumis melo, a plant found in Cameroon, is being used at the artisanal scale as vegetable in some Cameroon local dishes. These extracts are still to be exploited at the industrial level. In order to add more value to the Cameroon vegetative potential in general, the optimisation of pectin extraction from this plant was studied. Pectin was extracted from the fruits of C. M. by solubilisation in aqueous media followed by ethanol purification. A centred composite experimental design with three factors: temperature, pH and alcohol/water ratio was used to this effect. Responses considered were, water absorption capacity, solubility index and the emulsifying activity. The results obtained were analysed with the Statistica Centurion Software and the validation criteria for the obtained models where: the AMDA1 , the determination coefficient R2 and the sum of residuals. Sigma plot-11 software was used to plot surface response curves so as to better visualise the results. From this work, it follows that the optimum conditions for the extraction of pectin from Cucumis melo, was attained at pH 2.4, alcohol/water ratio of 1.5 and a temperature of 74°C.
Aims: To characterize the shale samples from Agbada formation and to develop an inhibitive water-based mud for the shale types. Study Design: Experimental. Place and Duration of Study: Department of Petroleum, University of Port Harcourt Rivers State, Agbada Formation Niger-Delta Region, between March 2011 and August 2012. Methodology: This study includes the determination of shale properties such as mineralogy, cation exchange capacity, native moisture content and total organic carbon content of the shale samples collected from two wells in Agbada Field. It also involves the establishment of an adsorption isotherm for the shale and the modeling of these isotherms using the Guggenheim, Anderson and Deboer model. Results: Based on the results of the dispersion and swelling tests, 3% Bentonite + 1% Potassium Chloride (KCl) were selected as the promising fluid. Well A exhibited the Type II isotherm which is common to most shale while Well B showed the Type V isotherm. Adsorption isotherm model predictions were in agreement with experimental observations. The samples from the wells exhibited dispersion after testing with deionized water. For Well A and B, 3% Bentonite + 1% Potassium Chloride (KCl) inhibits and yielded higher shale percent recovery values from dispersion tests. Conclusion: It was observed from adsorption isotherm models that the total organic carbon content is not a significant factor in the adsorptive and dispersive behaviors exhibited by the shale samples.
The objectives of this study were compare an alternative method for cocoa beans sampling with the standard method proposed by the European Union (EC 401/2006) and validate a method of Ochratoxin A determination. The alternative method applies to samples of 5 kg of cocoa beans while the standard method applies to samples of 10 kg. quality characteristics and validation parameters were determined according to Ivorian Coffee and Cocoa stock exchange and French (NFV03-110-1998) standards. Concerning quality characteristics, no significant difference at 5% risk was revealed in the values of the three parameters considered when assessing marketability quality requirements (moisture, graining and grades). As regards the validation of OTA determination method, the limits of detections and quantifications were 0.05 µg/kg and 0.20 µg/kg. The coefficients of variation for the tests of repeatability and reproducibility were respectively 0.26% and 5.67%. As for the extraction yield, it was equal to 86%. Furthermore, no significant difference (5% risk) was observed between the concentrations of OTA measured by the standard and alternative methods. Hence, although the alternative method goes with a mass reduction of samples analyzed, it did not alter significantly the results of the marketability as well as the concentrations of OTA.
Light Emitting Diode (LED) phototherapy (SEDRA 811) luminaire from Medical Engineering Group (MEG) was improved after the collaboration between the R&D group of MEG and National Institute for Standards (NIS). The initial LED luminaire consists of 10 Blue super LEDs which provide irradiance levels of 332 to 5719 µW/cm2±4.5% distributed over the effective surface area (treatment bed). The uniformity of these irradiance levels were 0.06 at the total effective area and 0.2 at central area. A new design of the LEDs position over the luminaire using elliptical lenses improves the irradiance uniformity to 3.7 times. At the new design the overall irradiance distribution was improved, the high irradiance levels areas shared their intensities with their neighbors of low irradiance levels. So while the high areas were reduced by 42%, the low ones were increased by 54%. As a result the new design provides more homogenous irradiance levels lying in the intensive levels. Also it provides the uniformity to reach 0.4 (the accepted border) at the central area (20 X 40 cm).
Pressure traverse in multiphase flow differs from single phase flow due to the differential flow rates of the different phases. Correlations developed to predict multiphase flow pressure traverse are mostly for vertical wells but Beggs and Brill model is one of the few models that is used for inclined pipes. The work seeks to show the improvement in the modification of the model. This project is based on studies carried out on multiphase fluid flow in pipes of any inclination using the Beggs and Brill flow model as the focus. Two cases were considered, the liquid holdup correction and Gas Liquid Ratio (GLR) variations in which the Beggs and Brill and Beggs and Brill Traverse models were compared. Due to the empirical nature of the Beggs and Brill model, pressure gradient predictions are far from accurate when compared with measured data in the field. This project seeks to reduce the error margin between predicted pressure gradient values and measured data. It was observed that for the same reservoir, fluid, and pipe properties, the Beggs and Brill Traverse Model is a better prediction tool than the Beggs and Brill model. Prediction errors were seen to increase with increase in length for GLR above 400 scf/stb while they were more accurate for pipes between 12,000 and 17,000 ft and pressures between 3,000 and 4,500 psi. However, the Beggs and Brill Traverse Model, is limited by the choice of correlations used in the computation of fluid properties.
In the present study, structural modification of mangiferin was carried out for structure activity relationship studies. One new compound and three known derivatives were prepared from mangiferin. All these compounds were synthesized and purified by standard procedures, identified by using physical and spectral (IR, 1H NMR, 13C NMR and MS) properties. The synthesized mangiferin derivatives were tested for In vitro antioxidant properties. Benzyl and methyl substituted mangiferin showed poor antioxidant activity than mangiferin. However, mangiferin derivatives substituted with acetyl and benzoyl groups were showed potent antioxidant activity than mangiferin in lipid peroxidation, p-NDA, deoxyribose and alkaline DMSO methods. But both the compounds failed to show potent analgesic and anti-inflammatory activities. In all these methods, standard drugs showed better activity than mangiferin and its derivatives.
Fingerprint has continued to enjoy dominance over other biometrics like face, iris, nose, signature among others in human verification and authentication. This is promoted by its major characteristics which include availability, uniqueness, consistency and reliability. Fingerprint verification and authentication involves the serial stages of enrolment, processing and matching. Enrolment through a number of fingerprint capturing devices helps to read the fingerprint into a target location from where processing takes place. Processing of a fingerprint image involves enhancement, feature extraction and singular point detection. Matching of fingerprint is performed based on the extraction results to establish its source or similarity level. The extraction of true singular (core and delta) and feature points is paramount for a true fingerprint matching and a number of algorithms had been formulated to accomplish it. This paper presents a review and evaluation of commonly known fingerprint singular point detection algorithms with emphasis on methodologies, strengths and weaknesses.