Faculty of Sciencehttp://41.89.96.81:8080/xmlui/handle/123456789/6582024-03-28T15:48:52Z2024-03-28T15:48:52ZEvaluation of concentration of mineral ions in water after defluoridation with bone charKariuki, Samuel Mwangihttp://41.89.96.81:8080/xmlui/handle/123456789/33312024-03-08T13:21:43Z2012-02-01T00:00:00ZEvaluation of concentration of mineral ions in water after defluoridation with bone char
Kariuki, Samuel Mwangi
Fluoride is an essential mineral that is present in trace amounts in the human tissue but is concentrated in bones and in teeth where it forms part of the bone and teeth crystalline structure. Ingestion of levels of fluoride greater than 1.5 mg/L during the period of tooth formation causes dental fluorosis while individuals depending on water supplies with fluoride levels greater than 3-6 mg/L or ingesting more than 10-20 mg of fluoride daily are likely to develop skeletal fluorosis after lO—2O years of exposure. Several defluoridation agents have been employed to remove fluoride from water. Bone char is the most widely used defluoridating agent in developing countries Kenya being one of them. Bone char is obtained by heating bones in a kiln at temperatures of 40()—500°C in a controlled flow of air. The chaired bones are packed in specially constructed defluoridating buckets. Apparently, due to the enormity of the fluoride problem, little attention seems to have been given to the effect the defluoridation agent may have on other essential mineral ions in water. Fluoride is believed to be removed from water by either the process of ion exchange with the hydroxyl ion of the bone hydroxyapatite or by adsorption. The metals which have long accumulated in the bone during the process of growth and metabolism could leach into water, or those in water could be captured just like fluoride during defluoridation. This study sought to find out whether when bone char is used as a defluoridating agent affects the concentration of some essential mineral ions in drinking water. Columns simulating defluoridation buckets were packed with bone char and water samples to be defluoridated collected after a resident time of 30 minutes. The water samples collected were analysed for changes in K+, Na+, Mg2+, Fey, Ca2+, Cl’, C032’, HCO3’, SO42’ and PO43" concentrations. Flame photometric method was used to determine the concentrations of KT and Na+ while Mg“, Fe2+ and Ca2+ were analysed using an Atomic Absorption spectrophotometer. The concentrations of chlorides, carbonates and bicarbonates were determined titrimetrically while that of phosphates was done colorimetrically. The concentration of Ki, Nal, Cl‘, C0321 HCO3‘, Ca2+ and Fe” decreased on defluoridation. The concentration of Mgr’, SO42’ and PO43’ increased on defluoridation but not above the WHO recommended levels. The pH also increased and in some cases above the WHO recommended range. However, defluoridation was not found to affect the quality of drinking water.
2012-02-01T00:00:00ZPredictive models for Nairobi stock exchange share priceMunyao, Joseph Kalusihttp://41.89.96.81:8080/xmlui/handle/123456789/33022024-02-28T08:28:06Z1998-04-01T00:00:00ZPredictive models for Nairobi stock exchange share price
Munyao, Joseph Kalusi
The Nairobi Stock Exchange (NSE) founded in 1954, as a Tcluntary organisation of the stockbrokers is now one of the most active capital markets in African where investors buy and sell snares and other securities. The share prices in the stock market ;sually vary with time and this can be attributed to factors such as changes in the economic growth of the region, threat of war or szrikes, government policies or political changes. These factors are non deterministic in nature and highly autocorrelated. Share prices movements in the NSE market are measured by an index based on 20 representative companies and is calculated on a iaily basis. The index is a general price movement indicator based on a sample or upon all the stock market companies and the sale and purchase decisions are based on its movements. The forecasts of future trends of share prices are often based an subjective factors, thus in this study appropriate forecasting models for determining the future share prices trends on the market are developed. The models are based on the stock market index as well as the share prices for Barclays Bank of Kenya Ltd, ICDC investment Company Ltd, Kenya Commercial Bank Ltd, Standard Chartered Bank Kenya Ltd, BAT Kenya Ltd and Kenya Breweries Ltd.
1998-04-01T00:00:00ZEffectiveness of selected mass extension methods on access to agricultural technologies among smallholder farmers in Laikipia West Sub County, KenyaKioko, Emily Ndanuhttp://41.89.96.81:8080/xmlui/handle/123456789/32692024-02-15T12:43:03Z2023-09-01T00:00:00ZEffectiveness of selected mass extension methods on access to agricultural technologies among smallholder farmers in Laikipia West Sub County, Kenya
Kioko, Emily Ndanu
Agricultural extension services play an important role in boosting agricultural productivity worldwide. Mass extension service delivery methods have been used to inform farmers about agricultural technologies by the government both at National and County level. Despite the investment in selected Mass extension methods, access to agricultural technologies by farmers remains limited. The purpose of this study was to establish the effectiveness of selected mass extension -methods which included Agricultural Exhibition, Road Extension Campaign and FM Radio on smallholder farmers’ access to agricultural technologies. The study was carried out in Laikipia West Sub County. The study employed descriptive survey research design. The target population constituted all the 35,220 households in Laikipia West and an accessible population of 32,400 smallholder households who own farm size of 0.4- 2.5 hectares. Multistage sampling procedure was used to obtain a sample size of 128 respondents comprising of 120 smallholder households and eight senior representatives of the eight major groups of agricultural stakeholders. The study used questionnaire for both the smallholder farmers and the agricultural stakeholders. The validity of the instruments was enhanced by seeking expert guidance of lecturers from the Department of Agricultural Education and Extension of Egerton University. The reliability of the instrument was estimated after pilot testing. Reliability coefficient of 0.74 was obtained. Data was analyzed with the help of Statistical Package for the Social Science (SPSS) version 24. Among Agricultural Exhibitions, Road Extension Campaigns and FM Radio, Mass extension methods, FM Radio was the most preferred effective method by smallholder farmers. The study concluded that FM Radio extension method was the most effective in promoting access to agricultural technologies among smallholder farmers in Laikipia West Sub County. The researcher recommended that County governments in collaboration with agricultural stakeholders develop policies to support FM Radio Mass extension method and to improve the exhibition and road extension methods so as to have diverse methods of extension service delivery.
2023-09-01T00:00:00ZAnalysis of wheat importation and its associated effects on domestic wheat production in KenyaToo, Henry Kipsanghttp://41.89.96.81:8080/xmlui/handle/123456789/32672024-02-15T09:07:08Z2022-09-01T00:00:00ZAnalysis of wheat importation and its associated effects on domestic wheat production in Kenya
Too, Henry Kipsang
Grains are presently the foremost necessary contributor to human food provided globally. In Africa, wheat economies are often characterized by a growing gap between domestic wheat supply and consumption. This is clearly indicated by the increase in wheat import bills in Africa. According to New trade theory imports are imperfect substitutes for domestic goods and services. As a result, changes in import dynamics are associated with changes in relative prices and income. In Kenya, government policy on wheat has been inadequate by focusing on production rather than being cognizant of the fact that Kenya has a structural deficit and will rely on wheat imports to fulfil its wheat requirements. Therefore, this study seeks to contribute towards a policy formulation framework for food security through analysis of wheat importation in Kenya. To achieve the objective, secondary time-series data from 2000 to 2019 was analyzed using the Auto-Regressive Distribution Lag-Error Correction Model (ARDL-ECM), Generalized Least Squares (GLS) method and Granger causality model. After data transformation, all variables were normally distributed indicated by the Jarque Bera test statistics. Unit root tests show with robustness that all variables tested were stationary either at level or first difference. The results of the bound test show that there is long run cointegration because the F-test statistic (10.596) was greater than the I (1) upper bound (3.990). The results of Granger causality exhibited three types of causality bidirectional, unidirectional, and independent. This reinforced the finding of existence of cointegration in wheat imports. The estimated import demand function captures 98.2% of total wheat imports in Kenya and this can be used to forecast and estimate the quantity of wheat imports in Kenya. In the ARDL-ECM model, the adjustment coefficient of 1.59 indicates how wheat imports are over-adjusted in Kenya. The findings of the study further reveal an inelastic response for relative prices, ending stock of wheat and government tariff on wheat, which have long run effects on wheat importation in Kenya. In the short run relative price was inelastic and the only variable that affects wheat importation in Kenya. To ensure that Kenya can feed its population wheat imports are only necessary for the short term but leads to growing import bills in the long run. Hence, the government should strive to come up with policies that promote competitive wheat production as it will create a multiplier effect on the economy in the long run. For instance, planting varieties that are in high demand in the Kenyan market.
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