Physical Sciences Research Papers/Topics

Design and Synthesis of Reusable Nanoparticles for Reversible Chemisorption of Hexavalent Chromium Anions from Aqueous Media and Catalysis

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...

Layered Rare-Earth Hydroxide Unilameller Nanosheets: Synthesis, Characterization, and Adsorption

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...

Aflatoxin B1 Affects Kenyan Markets: How It Can be Managed

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...

Isolation, Characterization and Biological Activities of Phytoconstituents from Lonchocarpus Eriocalyx Harms Leaves

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...

New synthetic pathways for thiocarbohydrazide and salicylaldehyde azine compounds

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...

The inter-play of the opto-electrical properties of cuprite and tenorite semiconductors for solar cell application

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...

Evaluation of CO2 in Saline Aquifers under Deep Ground Water Systems in Urumqi River Basin of Xinjiang, China

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...

Biogenic Synthesis of Gold Nanoparticles from Physalis peruviana and Application in Wound Healing

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. ...

Biogenically Synthesized Silver/Gold Nanoparticles, Mechanism and their Applications: A Review

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...

Electrochemical Study of Conducting Polymer/Lignin Composites

Electropolymerization and redox behavior of lignin composites were characterized by cyclic  voltammetry (CV), electrochemical quartz crystal microbalance (EQCM), and Fourier transform  infrared spectroscopy (FTIR). Oxidation of lignin (LG) composites mixed with different polymers such  as; Poly (o-phenylenediamine) (POPDA), Pyrrole (Py), 4-amino-3-hydroxynaphthalene-sulfonic acid  (AHNSA) on working glassy carbon electrode (GCE) were performed by cyclic voltammetry in a  three-electrode ...