Environmental & Physical Sciences

Environmental & Physical Sciences Research Papers/Topics

The Role of Bio-Extracted Reduced Graphene Oxide in the Crystallization Kinetics of Chitosan Bio-Polymer

Abstract/Overview Carbon nanomaterials have recently attracted wide scientific applications due to their tunable properties. These novel materials act as best fillers that can provide substantial benefits due to their high strength, thermal conductivity, and electrical conductivities. With their huge applications as bulk materials, when implemented in polymer matrix as fillers, they give rise to new promising materials with which their properties can be tuned to suit a particular applicat...

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...

Gametocytemia and Attractiveness of Plasmodium falciparum–Infected Kenyan Children to Anopheles gambiae Mosquitoes

Abstract/Overview It has been suggested that Plasmodia manipulate their vertebrate hosts to enhance parasite transmission. Using a dual-choice olfactometer, we investigated the attraction of Anopheles gambiae to 50 Kenyan children (aged 5–12 years) who were naturally infected with Plasmodium falciparum or non-infected controls. Microscopic gametocyte carriers attracted almost 2 times more mosquitoes than children who were parasite free, harboured asexual stages, or had gametocytes at su...

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...

Socio-economic factors influencing the spread of drinking water diseases in rural Africa: case study of Bondo sub-county, Kenya

Abstract/Overview Socio-economic and medical information on Bondo sub-county community was studied to help establish the relationship between the water quality challenges, community health and water rights conditions. Health challenges have been linked to water quality and household income. A total of 1,510 households/respondents were studied by means of a questionnaire. About 69% of the households have no access to treated water. Although 92% of the respondents appear to be aware that tr...

Environmental controls on growing-season sap flow density of Quercus serrata Thunb in a temperate deciduous forest of Korea

Abstract/Overview Sap flux density (SFD) measurements were used, in combination with morphological characteristics of trees and forest structure, to calculate whole-tree transpiration, stand transpiration (St) and mean canopy stomatal conductance (Gs). Analysis based on the relationships between the morphological characteristics of trees and whole tree water use, and on the responses of SFD and Gs to short wave radiation (RR), vapor pressure deficit (VPD) and soil water content (SWC) duri...

Socioeconomic factors influencing dependence of households on non-timber forest products in South Nandi Forest, Kenya

Abstract/Overview Forests are some of the key natural assets that provide a wide range of goods and services to forest adjacent communities. However, there is inadequate information on the factors that influence community members’ level of dependence on forest resources. This study examined and analyzed factors that influence dependence of households on non-timber forest products from South Nandi forest, Kenya. 431 household heads from 9 villages were interviewed using proportional rand...

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...

Morphometric study of Senna didymobotrya (Fresen.) H. S. Irwin and Barneby in Kenya

Abstract/Overview Herbal medicine has been used for many years and it remains widespread in developing countries while the use of complementary alternative medicine is increasing rapidly in developed countries. Senna didymobotrya is important for its medicinal use among many communities to treat a wide range of ailments. The study examines the patterns of morphological variation and phenetic relationships among 39 populations of S.didymobotrya in Kenya using17 quantitative and 17 qualitat...

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...

International Journal of Environment and Climate Change

Abstract Africa is under pressure from climate stresses and is highly vulnerable to the impacts of climate change. In Kenya, agriculture is the backbone of the economy making it an important contributor to food security of rural households. Currently crop productivity is being affected by continued climate variations and decline in soil fertility. Adaptation to climate change requires to be given high and urgent priority for sustainable crop production. A study was conducted in Mavuria ward,...

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. ...


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