Abstract/Overview A magnetically active nanocomposite material has been synthesized from the reaction mixture of magnetite core iron nano-particles electrostatically coated with SiO2, hydrotalcite nanosheets ([Eu8 (OH) 20 (H2O)n] 4+), and decatungstophosphate anion ([α-PW10O367−]). The resulting nanocomposite material, denoted as Fe34@SiO2@LEuH@PW10, is demonstrated to effectively adsorb chromate anions from aqueous solutions, the adsorption isotherms fit the Langmuir model with a capa...
Abstract/Overview Unilameller nanosheets with a lateral dimension of one nanometer have been isolated from a colloidal solution of europium-containing layered rare-earth hydroxide (LRH) material by the flocculation method. The nanosheets were achieved by changing pH of the colloidal solution from 6.7 to 11.5. The resultant flocculated nanosheets show high efficiency in sorption of fluoride anions from aqueous media (40 mmol/g), providing a potentially useful sorbent material for water p...
Abstract/Overview Aflatoxin B1 is a toxin produced as secondary fungal metabolites by the fungus Aspergillus, particularly A. flavus. The toxin has significantly contaminated the food supply chain especially cereals in Kenya. Kenya Bureau of Standards (KEBS) has recently banned five maize flour brands, citing high aflatoxin levels. They also suspended seven peanut butter products and the permits of their parent companies over aflatoxin contamination. The huge losses encountered by these c...
Abstract/Overview The plant species Lonchocarpus eriocalyx Harms (Fabaceae) is a deciduous slender tree or shrub which grows up to 15 m tall. It is an important medicinal plant in Kenya used to treat a wide range of ailments including eye infection, wound and ulcer. However, little is known about its chemical constituents. The present study aims to isolate secondary metabolites from the plant leaves along with their various biological activities. Eight compounds, namely friedelin (1), lup...
Abstract/Overview Thiocarbohydrazide synthesis is an important intermediate step for many hydrazine organic synthetic reactions. Synthesis of thiocarbohydrazide can be done by reaction of carbon disulfide with hydrazine (hydrazinolysis) in water at 0°C giving 25% yield (based on [hydrazine]). However, in this article, we achieve a 96% yield (based on [hydrazine]) by carrying out the reaction in methanol at 24°C. The thiocarbohydrazide is then used to synthesize 1,5-bis (2-hydroxybenzald...
Abstract/Overview The electrical and optical properties of cuprous oxide (Cu2O) thin films prepared by D.C. reactive magnetron sputtering technique have been systematically studied. The influence of the film deposition conditions on the opto-electrical properties has been investigated and has helped to solve the puzzles of difficulties associated with preparation of high quality Cu2O films. This is because there is usually co-deposition of phases of Cu, Cu2O and CuO during the preparation...
Abstract/Overview The future emissions of carbon dioxide (CO2) are likely to increase beyond the current levels due to rapid industrialization in China. Several methods have been proposed as possible mitigation strategies to reduce the anthropogenically emitted CO2 from the atmosphere and water. This study provided the description of stratigraphic structure of the basin through analysis between the regional groundwater flow and the injection of carbon dioxide. The geological and geomechan...
Abstract/Overview Wound management is key to healing. Poorly managed wounds lead to abnormal biological reactions and complications. Microorganisms, bacteria or fungi, infect such wounds leading to their chronic nature. Gold nanoparticles (Au NPs) show wound healing properties. In addition, ethnobotanical information from Siaya County in Kenya shows the leaves of Physalis peruviana L. to be effective in wound management. A combination of Au NPs and leave extracts of Physalis peruviana L. ...
Abstract In this work, zero-valent iron nanoparticles (nZVI NPs) were synthesized in (EW-Fe0) ethanol -water mixed system and have been evaluated for degradation in aqueous solution of metribuzin. The batch experiments at varying solution pH showed the degradation efficiency of 93.22%, 83.74% and 70.09% for the pH value 10, 7 and 4 respectively. Application of the varying dosage; (2% Feo w/v, 4% Feo w/v, 6% Feo w/v) reflected an increasing trend as per the recorded degradation efficiency of ...
Abstract/Overview As a result of climate change and rapid urbanization, attention increasingly turns to the management of water resources. Proper management of water resources has become a core concern for development practitioners and national governments, especially in the developing world. Accordingly, Community Participation (CP) has been touted as a viable model for managing water in resource scarce regions. This paper synthesizes literature written both from practice-focused and cri...
Abstract Proper characterization of total electron content (TEC) and scintillation is very important to global positioning system (GPS) users in communication, navigation, ionospheric or atmospheric studies. Quiet time variation of TEC is useful in the estimation and removal of ionospheric delay for global navigation satellite systems single-frequency positioning. During geomagnetic storms, the variations of ionosphere deviate from their quiet day pattern and can cause significant effects on...
Abstract Thin films of Tin Oxide co-doped with 28 atomic percentages of Aluminium (i.e. 28 at% Al) and varied concentration of Sulphur were prepared on 1mm thick, 1cm by 1cm glass substrates at 470 0C by Spray Pyrolysis technique. Films were produced from 2.0M solution of hydrous Tin Chloride dissolved in Ethanol with 38% Hydrochloric acid concentration, 1.5M aqueous Aluminium chloride and 2.0M aqueous solution of Ammonium Sulphide. The effects of Sulphur concentration on structural and elec...
Abstract Substitution behavior of the labile aqua ligand in four mononuclear ruthenium(II) terpyridyl complexes with different auxiliary N (pyridine) (Ru1), N^N (2,2′-bipyridyl (Ru2), 2′-(2-pyridyl)quinoline (Ru3), 2,2′-biqunoline (Ru4) ligands was investigated using three nucleophiles; thiourea, 1,1-dimethylthiourea and 1,1,3,3-tetramethylthiourea. The effect of concentration and temperature on the substitution behavior of the complexes were studied under pseudo-first order conditions...
Abstract A new 3,8′′-flavanone-flavonol dimer gnidiflavanone-flavonol (1) and 10 known compounds (2–11), including four rare primula-type flavones 2–5, were isolated from the roots of Gnidia apiculata. Compounds 2–5 and 7 were reported for the first time from the plant family Thymelaeceae. Structures of the isolated compounds were established by spectroscopic data, including 1D and 2D NMR (COSY, HMBC, HSQC and ROESY) and mass spectrometry, as well as by the comparison with literatu...
Abstract Paraoxon is an emerging organophosphate pollutant that is commonly used as a pesticide and a drug, hence increasing the risk of contamination of water supplies. Its intensive use for vector control has led to pollutions in soil and water. Paraoxon is very toxic, with an LD50 of 2 to 30 mg/kg in rats. It can be metabolized in the body from parathion; thus, exposure can lead to serious health effects. In this study, zero valent iron (Fe°/ZVI NPs) nanoparticles were synthesized and in...