This work focuses on the maize root as a one-membrane osmo-diffusive converter of free energy. Energy expenditures of the root on water transport by radial route as well as on xylem water uptake, occurring according to the principle of osmotic root pressure, are analyzed. The so-called practical method of osmo-diffusive energy conversion (Kargol 1990, 1993) and experimental data taken from the ...

The molecular size distribution and biochemical composition of the dissolved organic carbon released from natural communities of lake phytoplankton (photosynthetically produced dissolved organic carbon [PDOC]) and subsequently used by heterotrophic bacteria were determined in three lakes differing in trophic status and concentration of humic substances. After incubation of epilimnetic lake wate...

In this paper, it is presented a review about applications of biofilms in the degradation of contaminants in industrial effluents. Biofilms are typically comprised of water, microorganisms, extracellular polymeric substances (EPS), retained particles and dissolved and adsorbed substances. Water is the most significant fraction of the total mass of the biofilm, and it can vary from 70 to 95%. Po...

Macrophytes are important sources of dissolved organic carbon (DOC) to littoral zones of lakes, but this DOC is believed to be mostly refractory to bacteria, leading to the hypothesis that bacterial metabolism is different in littoral and pelagic zones of a large subtropical shallow lake. We tested this hypothesis by three approaches: (I) dissolved inorganic carbon (DIC) accumulation in littora...

A dissolved methane sensor based on silicone tube was designed, constructed and optimized.The silicone tube diameter, silicone tube length and helium flow rate (as the carrier gas(were considered as process parameters to be optimized.A continuous stream of helium (50 mL/min) was directed through the tubing, sweeping out the...

  ABSTRACT   Background : Natural uranium exists in earth crust and seawater. The concentration of uranium might increase by human manipulation or geological changes. The aim of this study was to verify susceptibility of laser flourimetry method to determine the uranium concentration in Caspian Sea and Persian Gulf water.   Materials and Methods : Laser flourimetric method was used to determine...

Acids, alkalies, salts, glucosides, and certain toxins diffuse more quickly into 0.9 per cent. salt solution than into agar-agar and gelatin suspensions. The inhibitory effect of the colloids grows with increase in concentration, which increase affects both the velocity and extent of the diffusion. In the case of gelatin the degree of diffusion is approximately in inverse proportion to the squa...

abstract   background : natural uranium exists in earth crust and seawater. the concentration of uranium might increase by human manipulation or geological changes. the aim of this study was to verify susceptibility of laser flourimetry method to determine the uranium concentration in caspian sea and persian gulf water.   materials and methods : laser flourimetric method was used to determine t...