نتایج جستجو برای: water bodies

تعداد نتایج: 627025  

Journal: :Acta biochimica Polonica 2011
Joanna Głowacka Magdalena Szefel-Markowska Małgorzata Waleron Ewa Łojkowska Krzysztof Waleron

The main goal of this study was to determine the distribution of potentially toxic cyanobacteria in 39 selected Polish water bodies. From the water bodies with blooms and also from those in which blooms were not visible 87 samples were investigated. For the first time samples from ponds localized in villages with high agricultural activities were included. Lakes for which microcystin concentrat...

2014
Arturo Sousa Leoncio García-Barrón Mark Vetter Julia Morales

The possible connectivity between the spatial distribution of water bodies suitable for vectors of malaria and endemic malaria foci in Southern Europe is still not well known. Spain was one of the last countries in Western Europe to be declared free of malaria by the World Health Organization (WHO) in 1964. This study combines, by means of a spatial-temporal analysis, the historical data of pat...

2007
MATTHEW E. POACH

Wind-driven surficial oxygen transfer into stationary water bodies has become increasingly important because the fate of many pollutants in these water bodies is strongly influenced by oxygen mass transfer. There are many existing correlations that can be used for predicting wind-driven surficial oxygen transfer; however, the actual prediction has been difficult because there are large variatio...

2017
Eshetu Yirsaw Wei Wu Xiaoping Shi Habtamu Temesgen

Monitoring the impact of current Land Use/Land Cover (LULC) management practices on future Ecosystem Services (ESs) provisioning has been emphasized because of the effect of such practices on ecological sustainability. We sought to model and predict the impacts of future LULC changes on subsequent changes in Ecosystem Service Value (ESV) in fragile environments undergoing complex LULC changes, ...

Journal: :The Journal of Experimental Medicine 1938
Edward G. Pickels Joseph E. Smadel

ULTRACENTRIFUGAL STUDIES OF THE CL DERMAL STRAIN OF VACCINE VIRUS WARRANT THE FOLLOWING CONCLUSIONS: 1. When suspended in increasing concentrations of sucrose, glycerol, or urea solutions, elementary bodies of vaccinia show variations in sedimentation rate which indicate changes in the density or size of the particles. For a given change in the density of the medium these changes are smallest w...

2010
Julie C. Brown Sidrah Rizvi Eileen J. Klein Rachel Bittner

BACKGROUND Organic foreign bodies swell when irrigated with water, potentially making extraction more difficult. As the degree and rate of swelling of different types of organic foreign bodies has not been established, we aimed to analyze the hydroscopic properties of different organic foreign bodies in body temperature water. METHODS Dry kidney beans, brown beans, peas, popcorn kernels, and ...

2012
Mario V. Balzan

Relatively little information is available on environmental associations and the conservation of Odonata in the Maltese Islands. Aquatic habitats are normally spatio-temporally restricted, often located within predominantly rural landscapes, and are thereby susceptible to farmland water management practices, which may create additional pressure on water resources. This study investigates how od...

2014
John A. Mischler Philip G. Taylor Alan R. Townsend

Primary production in freshwater ecosystems is often limited by the availability of phosphorus (P), nitrogen (N), or a combination of both (NP co-limitation). While N fixation via heterocystous cyanobacteria can supply additional N, no comparable mechanism for P exists; hence P is commonly considered to be the predominant and ultimate limiting nutrient in freshwater ecosystems. However, N limit...

Journal: :Environmental toxicology and chemistry 2005
Vincent Pettigrove Ary Hoffmann

High-molecular weight (> C16) hydrocarbons (HMWHs) are common pollutants in sediments of freshwater systems, particularly urban water bodies. No sediment quality guidelines exist for total hydrocarbons; more emphasis is placed on polyaromatic hydrocarbons, the most toxic component of hydrocarbons. A field-based microcosm experiment was conducted to determine whether unpolluted sediments spiked ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - پژوهشکده مهندسی فرایند 1395

abstract: mineral scaling in oil and gas production equipment is one of the most important problem that occurs while water injection and it has been recognized to be a major operational problem. the incompatibility between injected and formation waters may result in inorganic scale precipitation in the equipment and reservoir and then reduction of oil production rate and water injection rate. ...

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