Loading of nutrients from terrestrial ecosystems strongly influences the productivity and biogeochemistry of aquatic ecosystems. Human activities can supplement and even dominate nutrient loading to many lakes, particularly in agricultural and urbanized settings. For lakes in more remote regions such as the Adirondack Mountains of New York, N deposition represents the primary potential anthropo...

This paper analyses the relationship between net farm incomes and market values of cane land within the South African sugar industry. A comparison is drawn between market values represented by actual sales, and productive land values, which relate more specifically to net farm incomes. The aim of the paper is therefore to estimate the degree of correlation between net farm incomes and land mark...

Trace gas exchange of N2O, NO/NO2 and CH4 between soil and the atmosphere was measured in a typical Mediterranean pine (Pinus pinaster) forest during two intensive field campaigns in spring and autumn 2003. Furthermore, gross and net turnover rates of N mineralization and nitrification as well as soil profiles of N2O and CH4 concentrations were determined. For both seasons a weak but significan...

Biological system modelling is used to guide experimental work, therefore reducing the time and cost of in vivo implementation of newly designed systems. We introduce an improved modelling method, based on fuzzy logic and Petri nets. By using fuzzy logic to linguistically describe a biological process, we avoid the necessity to use kinetic rates, which are often unknown. We introduce a new set ...

The course of sugar fluxes into and out of protoplasts isolated from the mesophyll of Pisum sativum L. has been followed over brief time intervals (minutes). Light strongly stimulated net sugar influx at pH 8 as well as at pH 5.5. The proton conductor carbonyl cyanide m-chlorophenylhydrazone (CCCP) inhibited initial influx in the light, both at pH 8.0 and at pH 5.5. CCCP was without effect in t...

Concurrent changes in climate, atmospheric nitrogen (N) deposition, and increasing levels of atmospheric carbon dioxide (CO2) affect ecosystems in complex ways. The DayCent-Chem model was used to investigate the combined effects of these human-caused drivers of change over the period 1980–2075 at seven forested montane and two alpine watersheds in the United States. Net ecosystem production (NE...

This study has been investigated, the effects of three different polar polyacrylamides (anionic, cationic, and nonionic) on asphaltene deposition in porous media. All experiments were carried out in various dead oil flow rates (0.2, 0.1 and 0.02 cc/min) and different polymer concentrations (500, 2500, 4000 ppm). The results indicated that asphaltene precipitation was affected by the presence of...

The chance of developing lung cancer is increased through being exposed to cigarette smoke illustrated by studies. It is vital to understand the development of particular histologic-type cancers regarding the deposition of carcinogenic particles, which are present in human airway. In this paper, the mass transfer and deposition of cigarette smoke, inside the human airway, are investigated apply...

Gross and net erosion of tungsten (W) other plasma-facing materials in the divertor region have been investigated deuterium (D) helium (He) plasmas during dedicated experiments L- H-mode on ASDEX Upgrade after full-length experimental campaigns WEST tokamak. Net was determined via post-exposure analyses plasma-exposed samples full-size wall components, we conclude that same approach is applicab...