Enhancement of electrochemical properties of micro/nano electrodes based on TiO2 nanotube arrays

Titanium oxide nanotube (TiO2 nanotube) arrays were produced by anodizing titanium foils in two different electrolytes. The first electrolyte consisted of ethylene glycol containing 0.5 wt% NH4F and 4 vol% of distilled water to produce pure TiO2 nanotube arrays and the second consisted of HF aqueous solution (0.5 wt%) containing 0.5% polyvinylalcohol to produce carbon doped TiO2 nanotube arrays. The fabricated TiO2 nanotube arrays were subsequently annealed in the atmosphere of nitrogen. The morphology and crystal structure of fabricated arrays were characterized by means of scanning electron microscopy and X-ray diffraction. The electrical conductivity and capacitance of TiO2 nanotube arrays were investigated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Water contact angle and biocompatibility of fabricated nanotube arrays were investigated. The results showed that carbon doped TiO2 nanotube arrays annealed in the atmosphere of nitrogen have higher conductivity and capacitance than those of pure arrays annealed in the same atmosphere. Doping with carbon enhances the biocompatibility and wettability of TiO2 nanotube arrays. It has also noted that electrical conductivity and capacitance of TiO2 nanotube arrays were directly proportional to the tube wall thickness

Prevalence of Child Malnutrition in North Kivu, DRC: Evidence from Bunyuka Parish

Sub-Saharan Africa is the second most undernourished region in the world, with an estimated 265 million people in 2009. The Democratic Republic of the Congo (DRC) has the highest percentage of undernourished people in the region, 75% from 2004 to 2006. The Kivu region in Eastern DRC, in particular, has suffered through decades of conflict and lack of security and infrastructure obstruct data collection in this region. The main contribution of this paper is to present primary survey evidence on the prevalence of malnutrition in the village of Bunyuka in North Kivu. From a sample of over 700 mothers and 1400 children, we find significant prevalence of malnutrition and high dependence on nutritionally deficient food sources