Kenya Bureau of Standards

Nairobi, Kenya

Kenya Bureau of Standards

Nairobi, Kenya
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Ren X.-P.,China Institute of Metrology | Wang J.,China Institute of Metrology | Zhang Y.,China Institute of Metrology | Ombati W.,Kenya Bureau of Standards
Key Engineering Materials | Year: 2014

The growing and evolving dynamics in mass and force measurements has inevitably necessitated the need for high precision and accurate results. As a result, measurements in micro-gram(s) and nano-Newtons levels have increasingly attracted potential research interests. In an effort to develop such solutions, the National Institute of Metrology (NIM) has set up a new robot system CCR10 (readability 0.1μg) for accurate measurements of weight(s) (< 1 mg). This system is based on computer controls and linear-drive trains, and is used for calibration/verification of weight(s) below 10 g. A detailed description of the robot's metrological parameters and calibration results thereof is presented in the current paper. © (2014) Trans Tech Publications.


Ren X.P.,China Institute of Metrology | Wang J.,China Institute of Metrology | Dong L.,China Institute of Metrology | Wilson O.,Kenya Bureau of Standards
Key Engineering Materials | Year: 2015

Microgram weights have a wide range of applications in the mechanical testing of bio-material sensors and nanotechnology market which typically involves the manufacture of objects with dimensions of less than 100 nanometers. Now it is available with a calibration certificate in National Institute of Metrology (China) that customers can be assured of full traceability to the national primary standard of mass, NO.60, which make allow customers with specialized nanotechnology applications to use the weight values range from 0.05 mg to 0.5 mg with standard uncertainty of just 0.3 μg to 0.08μg. © (2015) Trans Tech Publications, Switzerland.


Maobe M.A.G.,Jomo Kenyatta University of Agriculture and Technology | Gitu L.,Jomo Kenyatta University of Agriculture and Technology | Gatebe E.,Jomo Kenyatta University of Agriculture and Technology | Rotich H.,Kenya Bureau of Standards | And 4 more authors.
World Journal of Medical Sciences | Year: 2013

A diploid fungus, Candida albicans, is a form of yeast that is a casual agent of opportunistic oral and genital infections in humans and is traditionally treated using herbs. Amongst the indigenous herbs used for the purpose in Kisii region, southwest Kenya are: Carissa spinarum, Urtica dioica, Warburgia ugandensis, Senna didymobotrya, Physalis Peruviana, Bidens pilosa, Leonotis nepetifolia and Toddalia sciatica. A study was carried out on these herbal plants in the year 2011and 2012. The objective was to determine the antifungal activity of these herbs that are also used for the treatment of diabetes, malaria and pneumonia. In the study, leaf samples of these plants were obtained from Kisii region, washed, air-dried and milled. The samples were extracted with four solvents namely hexane, dichloromethane, ethyl acetate and ethanol. Portions of the crude extracts were screened against Candida albicans, by the well diffusion method. Results showed that the standard antibiotics namely chloramphenicol, minocycline, erythromycin and cotrimoazol had diameters of the inhibition zones measuring (mm), 33, 32, 31 and 25, respectively which indicated inhibition of microbial growth. However, the extracts of hexane and solvents had no antifungal activity against the Candida albicans as they had diameters of the inhibition zones of 12 mm. The dichloromethane extracts of Leonotis nepetifolia and Bidens pilosa showed antifungal activity of diameters of the inhibition zones measuring 19 mm and 16 mm respectively. The ethyl acetate extracts of Leonotis nepetifolia, Bidens Pilosa, Senna didymobotrya, Toddalia asiatica and Physalis Peruviana recorded antifungal activity with diameters of the inhibition zones measuring (mm) 24, 18, 18, 17 and 15 respectively. The ethanol extracts of Leonotis nepetifolia and Physalis Peruviana displayed antifungal activity with diameters of the inhibition zones 27 mm and 19 mm, respectively. The dichloromethane, ethyl acetate and ethanol extracts of Leonotis nepetifolia recorded maximum antifungal activity against Candida albicans. The findings suggest that the herbal extracts of Leonotis nepetifolia, Bidens Pilosa, Senna didymobotrya, Toddalia asiatica and Physalis Peruviana have a potential to control Candida albicans as they have diameter zone of inhibition above 12 mm. © IDOSI Publications, 2013.


Papas R.K.,Yale University | Sidle J.E.,Moi University | Wamalwa E.S.,P.O. Box 5550 | Okumu T.O.,Kenya Bureau of Standards | And 5 more authors.
AIDS and Behavior | Year: 2010

Traditional homemade brew is believed to represent the highest proportion of alcohol use in sub-Saharan Africa. In Eldoret, Kenya, two types of brew are common: chang'aa, spirits, and busaa, maize beer. Local residents refer to the amount of brew consumed by the amount of money spent, suggesting a culturally relevant estimation method. The purposes of this study were to analyze ethanol content of chang'aa and busaa; and to compare two methods of alcohol estimation: use by cost, and use by volume, the latter the current international standard. Laboratory results showed mean ethanol content was 34% (SD = 14%) for chang'aa and 4% (SD = 1%) for busaa. Standard drink unit equivalents for chang'aa and busaa, respectively, were 2 and 1.3 (US) and 3.5 and 2.3 (Great Britain). Using a computational approach, both methods demonstrated comparable results. We conclude that cost estimation of alcohol content is more culturally relevant and does not differ in accuracy from the international standard. © 2010 Springer Science+Business Media, LLC.


Karau M.G.,Kenya Bureau of Standards | Kihunyu J.N.,University of Nairobi | Kathenya N.M.,Kenya Bureau of Standards | Wangai L.N.,Jomo Kenyatta University of Agriculture and Technology | And 2 more authors.
African Journal of Drug and Alcohol Studies | Year: 2010

The purpose of this study was to determine the amount of caffeine in non-alcoholic energy drinks and prepared teas using reverse phase HPLC. Caffeine was extracted from 19 different types of non-alcoholic beverages and prepared teas sampled from supermarkets in Nairobi Central Business District, Kenya. These were analyzed alongside a caffeine standard of 99 % purity by use of HPLC-UV detector at the wavelength of 272nm, Supelco HS C18 column 25 cm x 4.6 cm x 5 μm, oven temperature of 40 oC, mobile phase 80:20 (v/v) of methanol: water and mobile phase flow rate of 1.5mL/min. For quantitation purposes, serial dilution of the caffeine standard gave correlation coefficient (r) of 0.9993 and the retention time of 2.11±0.03 minute. Percentage recovery of caffeine from the column ranged from 89.78 to 105.59%. Limits of detection and quantitation were found to be 0.279 and 0.931 μg/mL respectively. It was found that Burn®, XL energy drink® and Red Bull® had the highest amount of caffeine. It was however noted that though most of the non-alcoholic beverages had high caffeine content they had no label claim. Copyright © 2010, CRISA Publications.


Wangai L.N.,Institute of Tropical Medicine | Wangai L.N.,Jomo Kenyatta University of Agriculture and Technology | Karau M.G.,Kenya Bureau of Standards | Njiruh P.N.,University of Nairobi | And 4 more authors.
African Journal of Infectious Diseases | Year: 2011

Detection of Plasmodium species by microscopy has been the gold standard for diagnosis of malaria for more than a century. Despite the fact that there is a significant decline in the number of positive cases reported from microscopy, antimalarial drugs prescriptions are on continuous increase as patients present with symptoms of malaria. This makes it difficult to establish accuracy, sensitivity and specificity of light microscopy in diagnosis of malaria in epidemic areas. This study was designed to compare microscopy with polymerase chain reaction as diagnostic methods for malaria in three epidemic areas in Kenya. A total of 356 patients presenting with malaria symptoms were diagnosed by microscopy and dried blood filter paper spots were collected from patient in Kisii, West Pokot and Narok districts. Plasmodium falciparum DNA was extracted from the dried blood filter samples. Primers specific for the Plasmodium Species were designed and used in a two step amplification of the Pfmdr gene. The PCR products were analyzed in ethidium bromide stained 1.5% agarose gel. It was found that 72 out of 350 specimens diagnosed as negative were positive for P. falciparum by nested PCR, while 6 which were microscopy positive were confirmed so by nested PCR. This study demonstrates that there is a high level of misdiagnosis which may either lead to denial for deserved treatment or undeserved treatment. Nested PCR detection of malaria parasites is a very useful complement to microscopy although it is expensive and takes long time. Additionally, smear negative patients suspected to have malaria should be subjected to PCR diagnosis to improve rational drug use. The economic burden of misdiagnosis and mistreatment of malaria outweighs that of PCR diagnosis, hence this diagnostic mode could be tenable in the long run even in rural areas.


Labite H.,Office of Hygiene and Basic Sanitation of Health Ministry | Lunani I.,Kenya Bureau of Standards | Van Der Steen P.,UNESCO-IHE Institute for Water Education | Vairavamoorthy K.,UNESCO-IHE Institute for Water Education | And 2 more authors.
Journal of Water and Health | Year: 2010

A quantitative microbial risk assessment was applied to evaluate the microbial risks of the Accra Urban Water System (AUWS). The exposure assessment was based on the count of indicator organisms in waste water from open roadside drains and in water and sand samples from the beach. The predicted total disease burden generated in a representative catchment of the AUWS (Odaw Catchment) was 36,329 Disability Adjusted Life Years (DALYs) per year, of which 12 and 88% are caused by, respectively, shortcomings in the water supply system and inappropriate sanitation. The DALYs per person per year were above the WHO reference value. The open roadside drain had the highest contribution to the disease burden. Of four possible interventions evaluated for health risk reduction, the highest efficiency in terms of DALYs averted per euro invested would be achieved by providing covers for the open roadside drains. © IWA Publishing 2010.

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