Seasonal variation in bacterial heavy metal biosorption in water samples from Eziama river near soap and brewery industries and the environmental health implications

Seasonal variation in bacterial heavy metals biosorption from soap and brewery industrial effluent samples from Eziama River in Abia State were analyzed for Pb, Hg, Fe, Zn, As, and Mn, using atomic absorption spectrophotometry. Bioaccumulation of the metals by bacteria showed the following trend > Fe >Zn >As > Pb > Mn (Rainy Season) and Zn > Fe > Mn > As > Hg > Pb (Dry season). Statistical analysis using of variance (ANOVA) showed significant differences in concentrations of Pb, Hg, Fe, Zn, As, and Mn level between the sampling zones at Eziama River. Seasonal changes in heavy metal concentrations, showed increases in Pb, Fe, and As from 1.32 x 10⁵ mg/L in the rainy season to 1.42 x 10⁵ mg/L in the dry season. Fe increased from 40.35 x 10⁵ mg/L to 42.1 x 10⁵ mg/L, while As increased from 2.32 to 2.48 x 10⁵ mg/L with a net increases of+56 and + 69 x 10⁵ mg/L respectively. However, Hg, Zn, and Mn concentrations decreased in the rainy season from 40.54 x 10⁵ mg/L to 39.24 x 10⁵ mg/L, 1.65 to 0.62 x 10⁵ mg/L respectively.     

Time variation of the X-ray spectrum and optical luminosity of SCO X-1

Results of rocket observations of SCO X-1 over the spectral range of 220 keV are presented. The observations have been performed partly in India and partly in Japan under the collaboration of the three groups. The present results are compared with results of similar observations carried out by the LRL (Lawrence Radiation Laboratory) group. Some of these X-ray observations were accompanied by simultaneous optical observations. Relationships between the hardness of the X-ray spectrum and the X-ray intensity and between the hardness and the optical luminosity are compiled. The relationships among the parameters (temperature, density and size) which characterize the postulated isothermal cloud model of SCO X-1 are given. They indicate that SCO X-1 is characterized by a temperature of about 10⁷–10⁸K, a density of about 10¹⁶–10¹⁷ cm^–3 and a radius of about 10⁸–10⁹ cm respectively. We further show that the temperature is inversely correlated with the size of the source; an increase in temperature corresponds to a decrease in the radius and an increase in density.     

Comment on “Origin of a late Eocene to pre‐Miocene buried crater and breccia lens at Fohn‐1, North Bonaparte Basin,Timor Sea: A probable extraterrestrial connection” by J. D. Gorter and A. Y. Glikson

Abstract— Gorter and Glikson (2000) proposed that the Fohn‐1 structure in the Timor Sea north of Australia probably is an impact structure. Examination of their evidence reveals that it is almost impossible to confirm any of their conclusions, as the authors do not provide sufficient detail of their experimental methods. Problems with the presentation of both seismic and geochemical data cast further doubt on their conclusions. Absence of evidence for shock metamorphism and non‐chondritic siderophile element patterns in the few samples analysed make it likely that Fohn‐1 is neither a probable, nor even a possible, impact structure.     

A TEST OF THREE FITTING CRITERIA FOR MULTIRESPONSE NON-LINEAR MODELING

This work evaluates objective functions for multiresponse non-linear modeling using computersimulations.Tests are performed under a variety of signal-to-noise ratios and noise variance-covariancestructures.The standard error of prediction for the model parameters,computed from 50 trials,is usedfor performance comparisons.The full rank and rank-deficient problems are considered.For the fullrank problem one model was investigated,a first-order two-step consecutive reaction model,and twoobjective functions were considered,the total sum of squares and the determinant criterion.Nodistinction could be made between the two objective functions for this model.For the rank-deficient case two models were investigated,a first-order two-step consecutive reactionas in the full rank case,and a pH titration model described by the Henderson-Hasselbalch equation.Three objective functions were investigated for the rank-deficient case,the total sum of squares,aweighted total sum of squares and the determinant criterion.The total sum of squares was found toperform poorly under all conditions tested compared to the weighted total sum of squares and thedeterminant criterion.The determinant criterion was found to perform much better than the other twocriteria when the data have a combination of a low signal-to-noise ratio and high variance-covariancenoise structure.