Environmental & Physical Sciences

Environmental & Physical Sciences Research Papers/Topics

IMPACT OF AGRO-FORESTRY PRACTICES ON RESILIENCE TO CLIMATE VARIABILITY AMONG FARMERS IN VIHIGA SUB-COUNTY, KENYA

Abstract Climate variability which is a reality in Kenya is manifested by fluctuations in climatic parameters, low agricultural production, land fragmentation, soil degradation, and loss of biodiversity. Addressing climate variability requires the use of ecologically based traditional climate smart agriculture systems such as agro forestry. In the past decade human lives, crops and livestock worth millions of shillings have been destroyed by increased intensity of extreme weather events in K...

Intensity of farmland cultivated and soil bulk density in different physiographic units in Nyakach district

Abstract/Overview A number of scholars agree that frequent cultivation raises soil bulk density through compaction and destruction of soil structure. However, no research has been conducted to establish how the intensity of farmland cultivated varies with soil bulk density in different physiographic units. High soil bulk density lowers root penetration and seed germination and therefore can be used as a measure of land degradation. Likewise the intensity of farmland cultivated can be used...

Effect of flooding on socio-economic livelihood of the farmers in lower Kano plain, Kisumu County, Kenya

Abstract/Overview Periodic flooding is a menace to agricultural activities in such regions due to disruptions on farmlands, grazing grounds, sweeping of human beings and animals, and socio-economic livelihood and infrastructure of the residents. The purpose of this study was to determine the effects of flooding on socio-economic livelihood of the households living in Lower Kano plain, Kisumu County. The study was conducted at Lower Kano plain for a period of three months and targeted 950 ...

RESTORATION STRATEGIES AND COMMUNITY ATTITUDES TOWARDS MINE PIT HAZARDS IN KAKAMEGA COUNTY, KENYA

Abstract Mining is an economic activity that has been practiced for time immemorial. Land degradation from old mines operations is known in almost all the countries but they have been few systematic surveys to quantify the nature of associated problems so as to prioritize remediation action. There is knowledge in the techniques of rehabilitating both operational and abandoned sites yet there is still delay in remediation action. The enforcement of the Environmental Management and Co-ordinati...

Variation in Total Electron Content Over Ethiopia During the Solar Eclipse Events

Abstract his work studies variations of ionospheric total electron content (TEC) during four distinct solar eclipse events over the Ethiopia region. Dual-frequency global positioning system (GPS) data obtained from UNAVCO over Addis Ababa (9.036°N, 38.76°E) and Bahir Dar (11.6°N, 37.34°E) stations are used to examine the ionospheric variability during two annular solar eclipses on 15 January 2010 and 1 September 2016, a partial solar eclipse on 4 January 2011, and a hybrid solar eclipse ...

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...


31 - 45 Of 2183 Results