Degradation in soils is the result of a combination of chemical and, predominantly, biological events (Bollag and Liu, 1990; Wu and Nofziger, 1999). A first-order degradation model is often used to simulate the decrease of residual mass of a chemical compound in a soil system after its application (Dykaar and Kitanidis, 1996; Walker, 1974). If the first-order rate constant or half-life remains ...

This study investigated the optimum conditions for the leaching of manganese-rich iron ore for subsequent beneficiation studies in laboratory scale. The experiments were carried out by varying the concentration of H2 SO4 solution and the leaching temperature. The properties of the iron ore was characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM)...

Four common techniques for the removal of dissolved oxygen from water have been examined: boiling at 1 atm, boiling under reduced pressure, purging with N(2) and sonication under reduced pressure. After treatment, the residual oxygen in solution was analysed by the Winkler method. Nitrogen purging for 20-40 min at flow rate of 25 mL/s was found to be the most effective oxygen removal method. Bo...

The seismic performance of hybrid braces composed of steel and shape memory alloy (SMA) was investigated in this paper. Six types of hybrid braces were used, constituted by SMA content of 0, 20, 40, 60, 80, and 100%. A nonlinear dynamic analysis was performed under El Centro earthquake records, with the maximum acceleration of 0.6g and 0.9g. Our results showed that the seismic performance, i.e....

The goal of the study was to investigate the effects of zinc ions of various concentrations on the nanostructure of membrane of red blood cells in in vitro experiment. The suspension of red blood cells extracted from whole human blood was used. The calibrated electroporation and the atomic force microscopy (AFM) were used to analyse damage to membrane nanostructure. We studied the haemolysis af...

In order to achieve integrated condition in the girth welding of high pressure natural gas transmission pipelines, the weld zones and its surrounding area should have good mechanical properties. Residual stresses are an important defect especially in the girth welding of the pipeline. In this study, two API X70 steel pipes (with spiral seam weld) of 56 inches outside diameter and 0.780 inch wal...

Removal of protein dissolved in water by batch foam separation was conducted with using ovalbumin (OA) as a model protein in the light of wastewater treatment reducing organic loading. The removal efficiency had a maximum value near the i.e.p. of OA (pH 4.6); thus, most experiments were conducted at pH 4.6. Typical experimental conditions; superficial gas velocity, U(g): 1.97 x 10(-2)-5.37 x 10...

background and aims: the safe, potent and effective live vaccines against measles, mumps and rubella as important childhood diseases have been available for several decades. several factors can affect the thermal stability of lyophilized vaccine. methods: in this study, the effect of residual moisture on thermal stability of 61 batches of mmr vaccine was investigated using an accelerated method...

In this paper we study some monotone behavior of the residual (past) entropy of order . We prove that, under some relation between the hazard rates (reversed hazard rates) of two distributions functions F and G, when the residual (past) entropy of order of F is decreasing (increasing) then the residual (past) entropy of G is decreasing (increasing). Using this, several conclusions regarding mo...