Jean-Louis BIGOURDAN and James M. REILLY Image Permanence Institute Rochester Institute of Technology Rochester, New York, USA ABSTRACT The effect of changing environments on paper stability was studied using three types of paper (acid-processed 100% cotton, acid-processed groundwood, and buffered groundwood). The study was based upon three cycling situations. The effect of humidity cycling alo...

Refrigerant leakage from failed braze joints is a multi-billion dollar problem for the global HVAC&R industry. Leaks are typically caused due to mechanical fatigue from extreme pressure cycling, temperature cycling including exposure to freeze/thaw cycles, or vibrational wear induced from rotating electrical machinery. Three tests to accelerate mechanical fatigue were devised to simulate real w...

Animals can be important in nutrient cycling in particular ecosystems, but few studies have examined how this importance varies along environmental gradients. In this study we quantified the nutrient cycling role of an abundant detritivorous fish species, the gizzard shad (Dorosoma cepedianum), in reservoir ecosystems along a gradient of ecosystem productivity. Gizzard shad feed mostly on sedim...

Conventional ecological theory predicts that predators affect nutrient cycling by decreasing the abundance or activity of prey. By using a predator-detritivore-detritus food chain in bromeliads, we show that predators can increase nutrient cycling by a previously undescribed, but broadly applicable, mechanism: reducing nutrient export by prey emigration. Contrary to expectations, predation on d...

This paper reports on patterns in plant-mediated processes that determine the rate of nutrient cycling in temperate fens and bogs. We linked leaf-level nutrient dynamics with leaf-litter decomposition and explored how the observed patterns were reflected in nutrient cycling at the ecosystem level. Comparisons were made among growth forms (evergreen and deciduous shrubs and trees, graminoids and...

According to theory, the rate and stoichiometry of microbial mineralization depend, in part, on nutrient availability. For microbes associated with leaves in streams, nutrients are available from both the water column and the leaf. Therefore, microbial nutrient cycling may change with nutrient availability and during leaf decomposition. We explored spatial and temporal patterns of mineralizatio...

to apply scientific and proper management of rangeland ecosystems, having information on health and functions indices of ecosystem is required. using landscape function analysis, the present study deals with assessing and comparing of ecological indices in northern and southern landscapes, darehkonari khashab of gachsaran. length and width for ecological patches in northern landscapes  in speci...

By assessing current leaf litter nutrient dynamics, we may be able to predict responses of nutrient cycling in tropical ecosystems to future environmental change. The goal of this study was to assess whether nutrient cycling is related to seasonal variation in rainfall in a wet tropical forest. We examined leaf litter of an old-growth tropical rain forest in N.E. Costa Rica over a 4-year period...

Major sedimentary nutrient cycles Phosphorus cycle Sulphur cycle Major gaseous cycles Nitrogen Cycle Carbon Cycle Ammonification Nitrification Nitrogen fixation Symbiotic nitrogen fixation Non-symbiotic nitrogen fixation Photosynthesis Light reaction Dark reaction Carbon dioxide cycle Micronutrients Plant uptake of trace elements (essential and non-essential) Factors influencing micronutrient u...