A combined experimental and computational fluid dynamics analysis of the dynamics of drop formation

This article presents a complementary experimental and computational investigation of the effect of viscosity and flowrate on the dynamics of drop formation in the dripping mode. In contrast to previous studies, numerical simulations are performed with two popular commercial computational fluid dynamics (CFD) packages, CFX and FLOW-3D, both of which employ the volume of fluid (VOF) method. Comparison with previously published experimental and computational data and new experimental results reported here highlight the capabilities and limitations of the aforementioned packages

Bioassay of herbal mosquito repellant formulated from the essential oil of plants

ABSTRACT Malaria, Dengue fever and Filariasis, are serious public health problem in tropical regions, especially in Africa and Asia and are transmitted through mosquito bites. For effective control of these diseases, therefore, there is need to prevent individual from mosquito bites. The effective and safe method is the use of mosquito repellent naturally obtained from medicinal plants instead of commonly available synthetic insecticides and repellents such as Organo Phosphorus Carbamate, N, N-Diethyl-3-methylbenzamide (DEET), and Dichloro Diphenyl Trichloroethane (DDT) which are carcinogenic and non eco-friendly. In this study, the repellency activities of four formulated herbal mosquito repellents from the essential oils of some selected MAPPs of Nigeria were evaluated. The essential oils were extracted by hyrodistillation method at 50°C using all glass Clevenger apparatus. These were then stored at 4 o c in the refrigerator pending further studies.Graded concentrations (6%, 8%, 10% and 12%) of the essential oils in a complex solution of polyethylene glycol, ethanol and water were prepared and their mosquito repellency activities was carried out in the laboratory against Standard Kisumu Strains of Anopheles gambiae. The result showed that both 8% and 10% formulations have the most promising activity exhibiting 68-95% repellency activities lasting for 2hours. The standard (odomos ® mosquito repellent cream) exhibited 75-100% repellency activities which also lasted for 2hours as compared to 8% and 10% formulations. The present study demonstrates the potential for using essential oils from medicinal plants as mosquito repellent

Food quality profile of pounded yam and implications for yam breeding

Open Access ArticleBACKGROUND Assessment of the key preferred quality traits in pounded yam, a popularly consumed yam food product in West Africa, is often done through sensory evaluation. Such assessment is time-consuming and results may be biased. Therefore, there is a need to develop objective, high-throughput methods to predict the quality of consumer-preferred traits in pounded yam. This study focused on how key quality traits in pounded yam proposed to yam breeders were determined, measured by biophysical and biochemical methods, in order to shorten the breeding selection cycle through adoption of these methods by breeders. RESULTS Consumer tests and sensory quantitative descriptive analysis (QDA) validated that preferred priority quality traits in pounded yam were related to textural quality (smooth, stretchable, moldable, slightly sticky and moderately hard) and color (white, cream or light yellow). There were significant correlations between sensory textural quality attributes cohesiveness/moldability, hardness, and adhesiveness/stickiness, with textural quality measurements from instrumental texture profile analysis (TPA). Color measurement parameters (L*, a*, and b*) with chromameter agreed with that of sensory evaluation and can replace the sensory panel approach. The smoothness (R2 = 1.00), stickiness (R2 = 1.00), stretchability (R2 = 1.00), hardness (R2 = 0.99), and moldability (R2 = 0.53) of pounded yam samples can be predicted by the starch, amylose, and protein contents of yam tubers estimated by near-infrared spectroscopy. CONCLUSION TPA and Hunter colorimeter can be used as medium-high throughput methods to evaluate the textural quality and color of pounded yam in place of the sensory panelists

A combined experimental and computational fluid dynamics analysis of the dynamics

of drop formatio