Plug-flow biofilm reactors colonized by microorganisms in streamwater were used to measure the concentration and composition of biodegradable dissolved organic C (BDOC) in White Clay Creek. During the 4-month study period, DOC ranged from 0.8 to 10.4 mg C liter-’ and was, on average, composed of 75% humic substances, 13% carbohydrates, 2% amino acids, and 18% > 100 kDa. The carbohydrates were p...

elevated atmospheric carbon dioxide and other green house gases have increased the earth temperature in recent century, which it affects all biochemistry cycles in soils. to examine the effect of atmospheric co2 concentration and temperature on n forms in soil solution in a calcareous soil, an experiment was conducted in a completely randomized design with factorial arrangement in the laborator...

A mathematical model for nutritional transport in capillary tissues exchange system in thepresence of magnetic field has been studied. In this case, the cell is deformed. Due to concentrationgradients, the dissolved nutrient in substrate diffuses into surrounding tissue. Theanalytical method is based on perturbation technique while the numerical simulation is basedon finite difference scheme. R...

Humic substances (HS) and natural organic matter (NOM) are natural organic compounds ubiquitous in the environment. However, some studies indicate that both HS and NOM can act as xenobiotics, e.g. induce hormone-like effects in fish, amphibians and invertebrates. Molecules of these substances contain a number of aromatic rings and conjugated double bonds--the so called chromophores. Irradiation...

This research based on record and collected data from four stations at Eymir Lake, Turkey, which are monitored daily in seven months. Water quality monitoring using former methods are time-needed and expensive, while the application of gene expression programming is more understandable, rapid, and reliable which is used in this article to provide a prediction for dissolved oxygen. The concentra...

With ultraviolet and visible light exposure, some pharmaceutical substances applied systemically or topically may cause phototoxic skin irritation. The major factor in phototoxicity is the generation of reactive oxygen species (ROS) such as singlet oxygen and superoxide anion that cause oxidative damage to DNA, lipids and proteins. Thus, measuring the generation of ROS can predict the phototoxi...