Browsing by Author "Ochieng, Ombaka"

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Analyses of geophagic materials consumed by pregnant women in Embu, Meru and Chuka towns in eastern province, Kenya
(2011) Mwangi, Gichumbi J.; Ochieng, Ombaka; Mwangi, Gichumbi, J.; Ombaka, Ochieng
Geophagy is the deliberate consumption of soil and clay deposits by animals, including man. During pregnancy all the nourishment needed by the developing fetus comes from the mother, either the food she eats or the supplement she may take. The geochemical and mineralogical composition of the materials which are consumed by pregnant women from Meru, Embu and Chuka open air markets were studied. The geophagic materials were subjected to standard digestion procedures and analyzed for full assay and elemental analysis for Co, Zn, Mg, Cu, Pb and Cd using Atomic absorption spectrometry and Energy-dispersive x-ray fluorescence spectrometry in 30 geophagic samples. The mineralogical composition was investigated using X-ray diffractometry (XRD). The geochemical analysis revealed that the geophagic materials contain high levels of silica from 48.59 to 60.27%. Geophagic materials from Embu showed the highest concentration of Pb at 0.96 ppm. The levels of Pb in all samples exceeded the levels recommended by WHO/FAO limits of 0.01 ppm. The levels obtained for Cd in all the samples did not exceed the WHO/FAO limits of 0.003 ppm. The XRD data showed that the geophagic materials of the area consisted mainly of silica.
Application of Banach space ideal properties in image transmission over wireless network
(2014-04) Musundi, Sammy Wabomba; Ochieng, Ombaka; Njogu, Muriuki; Kinyua, Charles
The Banach space operator ideals and nuclear maps have a large class of morphisms which behave as if they were part of a compact closed category, that is, they allow one to transfer variables between the domain and the codomain. We use the concept of nuclearity in functional analysis to establish application aspect of Banach space ideal properties in the transmission of image over wireless network based on the embedded system.
Concentration of Inorganic Contaminants in Shallow Borehole Water in Chuka Sub-County, Kenya
(Journal of Chemical, Biological and Physical Sciences, 2020-11-24) Edith. M., Rugendo; Eric C., Njagi; Ochieng, Ombaka
Groundwater from shallow aquifers is an important source of portable water in Chuka Sub-County. However, most shallow boreholes in Chuka Sub-County are undocumented and susceptible to contamination by both geogenic and anthropogenic activities. This study was conducted to evaluate the quality of shallow boreholes water in Chuka Sub-County. Samples were collected from twenty boreholes in Chuka Sub County during the dry and wet seasons. The temperature, pH and conductivity were determined in situ using a meter. The concentration of cations was determined using ICP-MS. The concentrations of anions were determined using standard APHA analytical methods. The temperatures and conductivities of borehole waters were within the limits set by KEBS and WHO. The pH of water in most boreholes during the wet season was within the limits set by KEBS and WHO for portable water. However, borehole water at Karandini (T15) was highly acidic (pH of 3.95) during the wet season. During the dry season, borehole waters were slightly acidic (4.42 - 6.44) except for the borehole at Ndagani market (T11), whose water was alkaline (pH = 8.75). The concentrations of trace and toxic cations and anions (NO3 - , SO4 2- , Cl and PO4 3- ) were within the limits set by KEBS and WHO. However, the concentration of nitrate in several boreholes during the dry season was within the range that cause chronic health effects. Groundwater from most boreholes in Chuka Sub-County is generally safe for domestic uses but require regular monitoring for quality.
Rapid, Economical and selective Compexometric Determination of Iron (III) in its synthetic alloys using 3 hydroxy-3- phynyl-1-(2,4,6-tribromophynyl)
(2013-09) Ochieng, Ombaka; Musundi, Sammy Wabomba; Gitonga, L. K .; Kibara, D.
The present study describes a simple, selective, rapid and economical method for the determination of iron (III) in its synthetic alloys using 3-hydroxy -3- phenyl-1- (2,4,6- tribro mophenyl) triazene as metallochromic indicator in the 𝑃𝐻 and temperature range of 2.5-3.0 and 20 −600𝑐 respectively. The colour and shape of the synthesized indicator was light yellow shinning needles having melting point of 590𝑐. It was crystallized from ethanol. The results of elemental study showed that, the values of C, H, N obtained experimentally agrees very well with those obtained theoretically. The colour at the end point changes from violet to light yellow using EDTA as a titrant. There is no interference in either determination from common metal and anion ions other than Pb(II), Cr(II), Mo(VI), Mn(II), U(vI), Cu(II), Cd(II), 𝐹−, 𝑃𝑂43−, 𝐶2𝑂42−, 𝐻𝑃𝑂42−. Reproducible and accurate results are obtained for 5.59 - 1.12mg of Iron with relative error less than ±1.79% and standard deviation not more than 0.10%. The results of the test method and reference method (Atomic absorption spectrophotometric) showed that, there is no statistical difference in the results by the two methods.
Synergistic Evaluation of Selected Plant Extracts on Potency of Pyrethrins against the Maize Weevil, Sitophilus zea-mais (MOTSCH.)
(Merit Res. J. Agric. Sci. Soil Sci., 2020) Michura, Anne Jerotich Garry; Magana, Adiel; Ochieng, Ombaka; Gachoka, Kennedy
The interest in utilization of botanical insecticides, particularly essential oils have become increasingly relevant in the control of insect pests. Many plant products and their bioactive compounds with repellent, antifeeding or insecticidal activity against stored product insect pests have been reported however, their levels of control are still wanting. The major issue is that the oil yields obtained are low, unstable and high costs involved in production to use on a commercial scale. Use of these oils in combinations or in formulations with botanical actives as synergists or stabilizers, may make them economically viable insecticides. The present study focussed on evaluating plant extracts (Black pepper seeds, Nutmeg seeds, coriander leaves and roots) as potential synergists in formulations with pyrethrins for possible use in protection of stored grains against Sitophilus zea-mais. Full dose response and synergism experiments were carried out on S. zea-mais at four concentrations of synergists at ratio 1:1 (synergist: pyrethrins) Topical application of synergist/ formulation on S. zea-mais was done in triplicate using Factorial Design in a completely Randomized Design layout. Experiments were conducted under controlled laboratory conditions of 27 ± 2OC and 60 ± 5%RH with normal day light hours. Probit analysis was used to determine the lethal concentration (LC) of pyrethrins and ANOVA was used to obtain the mean mortality differences of S. zea-mais at P ≤ 0.05. LC20 value for pyrethrins was found to be 2,200 ppm. In formulations of synergist: pyrethrins, coriander leaves extract (CLHE), Nutmeg seed extract (NMHE) and Black pepper seed methanol extract (BPSME) were statistically significant (P ≤ 0.05) 24 h after exposure. PBO registered higher percentage (83.33 ± 12.02%) mortality followed by CLHE (46.67 ± 3.33%), BPSME (43.33 ± 6.67%). BPSME and NMHE co-toxicity values were below 20 and -20 respectively while in PBO, BPSHE and CLHE values were above 20. Plant extracts BPSHE and CLHE and PBO synergized the toxicity of pyrethrins in all concentrations over 72 h exposure duration with co-toxicity factors above 100. BPSME was shown to be an additive in the formulation and only a synergist at 20,000ppm while NMHE was antagonistic to pyrethrins. Increasing the concentration of a plant extract did not correspond to increased efficacy of the formulation. Efficacy of the synergist- pyrethrins formulations at lower concentrations can be economically viable since average percentage mortalities will not be different from that of higher concentrations when time of interaction is prolonged. It is recommended that BPSHE and CLHE can be synergists to pyrethrins when formulations are exposed to insects for 72 h duration