Analyses of the physicochemical and microbiological qualities of selected sachet water brands in Awka, Anambra State, Nigeria

This study analyzed the physicochemical and microbiological qualities of five sachet water brands that are mostly consumed in Awka. The researchers used respective meters for determination of physical parameters, an atomic absorption spectrophotometer machine for heavy metals determination and streak-plate method for the determination of microbiological parameters. The five sachet water brands that were used for the study were elicited from the respondents in Awka using a questionnaire. Averaged results of the physicochemical parameters of the selected sachet water brands showed that pH yielded 6.86, electrical conductivity yielded 0.2304μS/m, turbidity yielded 0.0082NTU, total dissolved solids yielded 55.62mg/l, and total suspended solids yielded 42.98mg/l. In addition, averaged results of the heavy metal parameters for the selected sachet water brands showed that lead yielded 0.0178mg/l, cadmium yielded 0.0088mg/l, copper yielded 0.0146mg/l, iron yielded 2.28mg/l, zinc yielded 1.044mg/l, chromium yielded 0.0298mg/l and cobolt yielded 1.0366mg/l. Results of the microbiological parameters showed that for total count, Aqua-Rapha yielded 11 x 105MPN/100ml, Ben-Lovers yielded 46 x 103MPN/100ml, Rock-Tama yielded 48 x 103MPN/100ml, Ice-Pack yielded 99 x 102MPN/100ml and Marvel yielded 84 x 103MPN/100ml. The study recommended that sachet water vending machines should be properly disinfected to guard against indicator organisms entraining into them which can serve as sources of sachet water contamination. Keywords: analyses, microbiological, physicochemical, quality, sachet water, Awka

Analyses of the physicochemical and microbiological qualities of selected sachet water brands in Onitsha, Anambra State, Nigeria

This study analyzed the physicochemical and microbiological qualities of five sachet water brands that aremostly consumed in Onitsha. The researchers used respective meters for the physical parameters, an atomicabsorption spectrophotometer machine for the heavy metal determinations and streak-plate method for thedetermination of microbiological parameters. The five sachet water brands that were used for the study wereelicited from the respondents in Onitsha using a questionnaire. Averaged results of the physicochemicalparameters showed that pH yielded 5.56, electrical conductivity yielded 0.2286μS/m, turbidity yielded0.0058NTU, total dissolved solids yielded 54.28mg/l and total suspended solids yielded 35.3mg/l. In addition,averaged results of the heavy metal parameters showed that lead yielded 0.0108mg/l, cadmium yielded0.0284mg/l, copper yielded 0.0386mg/l, iron yielded 2.15mg/l, zinc yielded 0.738mg/l, chromium yielded0.0412mg/l and cobolt yielded 0.0902mg/l. Results of the microbiological parameters showed that for totalcount, Olek yielded 79 x 103MPN/100ml, Nation yielded 48 x 103MPN/100ml, De-beste yielded 19 x104MPN/100ml, Jemok yielded 66 x 103MPN/100ml and Aqua-Rapha yielded 98 x 102MPN/100ml. Thestudy recommended that the qualities of sachet water brands should be in line with NSDWQ standards with aview to raising standard in the industry and reassuring the public of the safety of these products for publicconsumption. Keywords: analyses, microbiological, Onitsha, physicochemical, quality, sachet water

Precipitation pathways a channel of nutrient cycling in an Entandrophragma cylindricum (sprague) Sprague plantation in Onne, rivers state, Nigeria

Field experiment was conducted in 2011 at Forestry Research Institute of Nigeria (FRIN), Swamp Forest Research Station, Onne, Rivers State Nigeria, to study nutrient cycling through precipitation pathways in Entandrophragma cylindricum plantation. The experiment was 3 x 12 factorial in a Randomized Complete Block Design (RCBD) with three replications. The treatments were Time in 12 levels (months of the year) and Precipitation pathways in 3 levels (stemflow, throughfall and rainfall). In the precipitation pathways, results of throughfall, stemflow and rainfall were 7.31, 7.38 and 6.56 for pH; 56.00, 88.67 and 39.67 mg L-1 for Nitrogen; 7.93, 8.34 and 7.70 mg L-1 for Phosphorus; 6.51, 2.59 and 0.92 mg L-1 for Potassium; 19.10, 22.93 and 14.45 mg L-1 for Magnesium; 63.02, 75.34 and 49.49 mg L-1 for Chlorine; 0.58, 0.88 and 0.48 mg L-1 for Lead; 0.07, 0.12 and 0.05 mg L-1 for Cadmium respectively. Stemflow and rainfall gave significantly the highest and the least nutrient contents. Nutrient released in the precipitation pathways were in the following significant order: stemflow > throughfall > rainfall. The study showed that precipitation pathways can be channels through which nutrients are released into the soil. Keywords: Precipitation pathways, stemflow, throughfall, rainfall, nutrient element

Precision Electroweak Measurements on the Z resonance.

We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron–positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLD experiment using a polarised beam at SLC. The measurements include cross-sections, forward–backward asymmetries and polarised asymmetries. The mass and width of the Z boson, mZ and ΓZ, and its couplings to fermions, for example the ρ parameter and the effective electroweak mixing angle for leptons, are precisely measured: The number of light neutrino species is determined to be 2.9840±0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward–backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, , and the mass of the W boson, . These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of mt and mW, the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than at 95% confidence level