Natural & Applied Sciences

Research Papers/Topics Natural & Applied Sciences

Genetic Diversity Of Faidherbia Albida (Del.) A. Chev Collections Held At The World Agroforestry Centre (Icraf) Nairobi, Kenya

ABSTRACT Faidherbia albida (Del.) A. Chev is a tree species native to Africa and the Middle East. It is an important agro-silvo pastural species owing to its morphological and physiological dynamics that mediate improvement of soil structure and fertility while offering several other benefits to farmers and the environment. Key among these is its reverse phenology, a phenomenon that allows the tree to compete minimally with crops while providing a favorable microclimate for their growth. It ...

Simulating Natural Turbulent Convection Fluid Flow In An Enclosure Using The Two-Equation Turbulent Models

  ABSTRACT This study assesses the performance of three numerical turbulence models; k -e , k -w and k -w - SST in predicting heat transfer due to natural convection inside an air filled cavity. The heat transfer due to natural convection inside a rectangular closed cavity should be modeled to include the effect of turbulence for Rayleigh number greater than or equal to 9 10 .The non-linear terms i j u u and qi u in the averaged momentum and energy equations respectively were modeled using...

SSA Research 135 PAGES (28050 WORDS) Mathematics Thesis
Functionalized Geopolymers Derived From Clay And Rice Husk Ash For Removal Of Selected Heavy Metals And Methylene Blue From Aqueous Solution

ABSTRACT With the onset of industrialization, humanity has witnessed various ecological issues in the society and disturbance of ecosystem. Heavy metals and methylene blue are very toxic substances known to cause detrimental effects to human health when ingested even at low concentrations. Several techniques are available for removal of heavy metals, and dyes from the wastewater such as chemical precipitation, ion exchange, adsorption, membrane among others. Among these technologies adsorptio...

SSA Research 202 PAGES (52731 WORDS) Chemistry Thesis
Evaluation Of Antioxidant And Anti-Inflammatory Activities, Total Phenolic And Flavonoid Content In Selected Medicinal Plants, Non-Edible Medicinal Mushrooms And Seaweed

ABSTRACT Medicinal plants play a major role for sources of lead compounds in drug discovery. Studies done have shown that plants, fungi such as mushrooms and seaweeds are a good source of bioactive compounds with anti-inflammatory, antioxidant, anti-cancer and antimicrobial activities. Antioxidants play main role by hindering oxidation by protecting cells from damage by free radicals. This protects the body from cancer and other chronic ailments like heart diseases. Anti-inflammatory effect i...

SSA Research 74 PAGES (14394 WORDS) Chemistry Thesis
Assessment Of Levels Of Some Active Skin Lightening Compounds In Selected Facial Creams And Soaps In The Kenyan Market

ABSTRACT Cosmetics are generally used to improve the appearance by the removal or correction of blemishes and to treat diseases of the human skin and hair. Skin-lighteners which include hydroquinone, mercury, arbutin, kojic acid, ascorbyl glucoside, magnesium ascorbyl phosphate have been frequently used in skin lightening creams and soaps. However chronic exposure to mercury compounds in skin lightening creams and soaps may lead to various disorders such as nephritic, peripheral neuropathy, a...

A Numerical Study Of Turbulent Natural Convection In A Rectangular Enclosure With Localised Heating And Cooling.

ABSTRACT This study models natural turbulent convection in a rectangular enclosure with localized heating and cooling. The equations used in modeling the flow are the equation of continuity, momentum equation and the energy equation. These equations are decomposed using the Reynolds decomposition then the decomposed equations are non – dimensionalised and reduced using the Boussinesq assumptions. The model that is considered is a rectangular enclosure with one side wall being heated and the...

Determination Of Lead, Cadmium And Nickel In Henna Leaves And Cosmetic Henna Products Within Lamu County, Kenya

ABSTRACT Lawsonia inermis Linn, commonly known as henna, is an ethno botanical plant which has been used since antiquity for cosmetic and medicinal purposes. Henna painting is an art of beautification which is commonly practised by the people of Lamu County. Heavy metals such as Pb, Cd and Ni are toxic and commonly found in cosmetic products such as henna. The level of these metals in henna leaves and henna products from Lamu is not known. The aim of the study was to determine the level of Pb...

SSA Research 82 PAGES (17938 WORDS) Chemistry Thesis
Analysis Of Essential Trace Elements In Selected Medicinal Plants Used In Kenya

ABSTRACT Kenya is endowed with nature where hundreds of medicinal plants are available. During photosynthesis and respiration process in plants, animals and other organisms, ions of metal elements play a major role with a few of the elements being essential to the body as nutrients. Trace elements Zn, Cr, V and Se with known immunological response and healing properties were analysed from selected medicinal plants available in Kenya. These plants were; Prunus africana, Urtica massaica, Mayten...

The Study of Ethnobotanical Uses by Local Healers in Taktse Chiwog from Central Bhutan

Aim: To document the ethnobotanical uses in Taktse Chiwog (Village blocks) by local healers Study Design: Semi-structured interview and direct interview was conducted with the prior approval from the Chiwog official. Two local healers/informants were contacted for interview before field visits based on their popularity and experience of using medicinal plants in their locality. Place and Duration of Study: The study was conducted at Taktse Chiwog, Trongsa Dzongkhag, Bhutan between July and O...

Ethnobotanical Study on Wealth of Homegardens in Gosiling Gewog of Tsirang District

Aim: To document the medicinal uses of homegarden plants by local healers. Study Design: Semi-structured interview was conducted with the prior approval from the gewog official. Five local healers were contacted for interview before field visits based on their popularity and experience of using medicinal plants in their locality. Place and Duration of Study: The study was conducted at Gosiling gewog, Tsirang District, Bhutan between May and June 2016. The homegarden and agricultural pract...

Dorji Penjor 11 PAGES (4653 WORDS) Botany Paper
Calcium Chloride Supported On Purified Spent Bleaching Earth As Potential Adsorptive Material For Air Dehumidification Application

ABSTRACT The cosmic limitation of high humid environment in tropic regions spurs a lot of interest to the development of low cost desiccants. Calcium chloride has been indicated as the oldest adsorbent desiccant among chemicals and gas dehydration industries. However, calcium chloride dissolution behaviour makes it difficult to be utilized well as desiccant. The first attempt to suppress deliquescence behavior for dehumidification purpose was in 1976 where silt loam was used as the host mater...

In Vitro Response Of Phomopsis Theae To The Products Of Azadirachta Indica And Extracts Of Warburgia Ugandensis

ABSTRACT Tea is one of the major cash crops in Kenya and a means of livelihood to people living around the region where it is grown. Branch and collar canker disease is among the many diseases which affect the crop hence reducing its production. Methods used to control the disease mainly involve the use of chemical fungicides which are toxic and not environmentally friendly. This study was therefore done to determine the use of plant products and extracts to manage the disease. Among the prod...

Flow Of Contaminants In Urban Ground Water

Groundwater contamination occurs when man-made products such as gasoline, oil, road salts and chemicals get into the groundwater and cause it to become unsafe and unfit for human use. Drinking contaminated groundwater can have serious health effects. Diseases such as hepatitis and dysentery may be caused by contamination from septic tank waste. Poisoning may be caused by toxins that have leached into well water supplies. Wildlife can also be harmed by contaminated groundwater. Other long...

Determination Of Lead And Cadmium Levels In Decorative Paints Sold In Nairobi, Kenya

ABSTRACT  Lead and cadmium which are heavy metals may be used as paint pigments as they speed drying, increase durability, retain a fresh appearance and resist moisture that causes corrosion. Both lead and cadmium metals are toxic, poisonous and are carcinogen, lower IQ, cause hyper activity among other effect. Their presence in decorative paints can produce toxic effect to both painters and those who live in painted houses or painted product especially children who use painted toys can be i...

Mathematical Modelling Of Variable Viscosity Hydromagnetic Boundary Layer Flow With Thermal Radiation And Newtonian Heating

ABSTRACT Magnetohydrodynamic boundary layer flow involving a fluid of varying viscosity subject to thermal radiation and Newtonian heating has various applications in industry and engineering some of the applications include designing of cooling systems used in electronic devices, cooling of nuclear reactors, harvesting of solar energy, thermal insulation, heat exchangers and in geothermal reservoirs. Heat transfer by thermal radiation is of significance to engineering processes that occurs ...


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