The use of riverine dissolved organic matter by the heterotrophic bacteria associated with a culture of the cyanobacterium Microcystis aeruginosa and release of simple nitrogen compounds were studied in an experimental series. Bacteria reduced the bulk of dissolved organic nitrogen (DON) by half, but when associated with M. aeruginosa, DON was excreted and its concentration rose by 13%. During ...

A LC/MS/MS method was developed for determining florfenicol and chloramphenicol in animal feed. The analytes were extracted with ethyl acetate, and the extracts were evaporated to dryness. The residue was dissolved in acetone-hexane mixture and passed through a silica cartridge and a SPE cartridge. The collected eluant was evaporated and the residue was dissolved in acetonitrile-water mixture f...

The paper presents the design of the integrated control system applied to Sequencing Batch Reactor (SBR) in a biological Wastewater Treatment Plant (WWTP) in Swarzewo, which operates under activated sludge technology. Based on the real data records, ASM2d biological processes model and aeration system model, hierarchical control system for dissolved oxygen tracking and cycle management is desig...

mobile carrier properties of two schiff base ligands, named bis(2-hydroxypropiophenone)-1,2-propanediimine (n2o2) and bis(1'-hydroxy-2'-acetonaphthone)-2,2'-diiminodiethylamine (n3o2), dissolved in dichloromethane for the extraction of copper(ii) ions from an ammonium buffer feed phase into a nitric acid solution (receiving phase) were investigated and compared. the parameters influencing the t...

Bubble nucleation phenomenon in presence of gas impurities is studied by microcanonical molecular dynamics simulation for Lennard-Jones fluid. First, we investigate effect of molecular diameter of dissolved gas on the nucleation rate with pressure change. As a result, we find increase of the nucleation rate with increase of the pressure, which we call "inverse" pressure phenomenon, when interac...

A method for determination of juglone in leaves and hulls of Pterocarya fraxinifolia was developed, based on RP-HPLC. This compound was extracted from leaves and hulls by chloroform refluxing about 2 hours. The chloroform was evaporated under low pressure at   50 ºC to produce a dry residue. The remained materials were dissolved in acetonitrile to be used for determination of this compound....

In this work, mechanical alloying was employed to produce Ti-50Al and Ti-45Al-5Cr (at%) alloys. Alloying was performed in a planetary mill and the alloying time varying from 5 to 70h. Characterization of the powder mixture was performed by X-ray diffraction (XRD), SEM analyses and DTA test, during mechanical alloying and after annealing at 1100°c in vacuum oven. The results showed, after 50h of...

During surface Fadlelmawla', K.J. Reddf, and G.F. Vance3 coal mining, rock material overlying the coal is redistsibuted with respect to its original stratigraphic position. Oxidation of the redistributed backfill material may release dissolved selenium (Se) to groundwater in backfill systems. This study was initiated to examine the chemistry of Se in the groundwater backfill environment. Both b...

The super-saturation condition has to be provided to form gas hydrates. Consequently, the prediction of the guest molecule fraction in the aqueous phase is crucial in the study of the gas hydrate kinetics. In the present work, several experiments were carried out in a semi-batch reactor in order to determine the mole fraction of methane and ethane during gas hydrates formation (growth stage...