Search results for "Environmental Biotechnology"
showing 10 items of 568 documents
Testing a new rill flow resistance approach using the Water Erosion Prediction Project experimental database
2018
In this paper, a recently theoretically deduced rill flow resistance equation, based on a power‐velocity profile, was tested using the Water Erosion Prediction Project database. This database includes measurements of flow velocity, water depth, cross section area, wetted perimeter, and bed slope that were made in rills shaped on experimental sites distributed across the continental United States. In particular, three different experimental conditions (only rainfall, only flow, and rain with flow) were examined, and for each condition, the theoretically based relationship for estimating the Γ function of the power velocity profile was calibrated. The results established that (a) the Darcy‐We…
Testing slope effect on flow resistance equation for mobile bed rills
2018
In this paper, a recently theoretically deduced rill flow resistance equation, based on a power-velocity profile, is tested experimentally on plots of varying slopes in which mobile bed rills are incised. Initially, measurements of flow velocity, water depth, cross-sectional area, wetted perimeter and bed slope conducted in 106 reaches of rills incised on an experimental plot having a slope of 14% were used to calibrate the flow resistance equation. Then, the relationship between the velocity profile parameter Î, the channel slope, and the flow Froude number, which was calibrated using the 106 rill reach data, was tested using measurements carried out in plots having slopes of 22% and 9%. …
Rainfall timing and runoff: The influence of the criterion for rain event separation
2016
Abstract Rain is not uniform in time and space in semiarid areas and its distribution is very important for the runoff process. Hydrological studies usually divide rainfall into events. However, defining rain events is complicated, and rain characteristics vary depending on how the events are delimited. Choosing a minimum inter-event time (MIT) is a commonly used criterion. Our hypothesis is that there will be an optimal MIT that explains the maximum part of the variance of the runoff, with time to runoff used as a surrogate. The objective is to establish a procedure in order to decide upon this optimal MIT. We developed regressions between time to runoff (T0) and three descriptive variable…
Thematic Issue on Soil Water Infiltration
2017
Interpretive Summary: When water is applied to the land surface through irrigation or rainfall, it infiltrates into the soil surface and percolates deeper through the soil profile under the influence of gravity and capillary forces. Soil infiltration is one of the most complex processes within the terrestrial hydrologic cycle, yet the process is only partially understood. Infiltration is affected by the physical, chemical and biological properties of the soil, vegetation cover, rainfall, irrigation properties, and management practices. Measurement of infiltration rate is essential in studies concerning water budget, hydrology, runoff, erosion, irrigation, drainage and water conservation. Ho…
Exploring the spatial relationship between airborne-derived red and far-red sun-induced fluorescence and process-based GPP estimates in a forest ecos…
2019
International audience; Terrestrial gross primary productivity (GPP) plays an essential role in the global carbon cycle, but the quantification of the spatial and temporal variations in photosynthesis is still largely uncertain. Our work aimed to investigate the potential of remote sensing to provide new insights into plant photosynthesis at a fine spatial resolution. This goal was achieved by exploiting high-resolution images acquired with the FLuorescence EXplorer (FLEX) airborne demonstrator HyPlant. The sensor was flown over a mixed forest, and the images collected were elaborated to obtain two independent indicators of plant photosynthesis. First, maps of sun-induced chlorophyll fluore…
Flood frequency analysis for an urban watershed: comparison between several statistical methodologies simulating synthetic rainfall events
2016
To obtain the flooding frequency distribution for an urban watershed, different methods based on simulations of synthetic rainfall events were compared with an empirical analysis of the flooding data and with the results of long-term simulations. A copula-based multivariate statistical analysis of the main hydrological variables was proposed to generate synthetic hyetographs. Two different approaches were adopted to assess a temporal pattern to the synthetic rainfall: one analyses all available historical rainfall patterns, and another adopts the cluster analysis in three different variants to reduce the computational effort of the analysis. To test the methodology reliability, the analysis…
Analysis of Geometrical Relationships and Friction Losses in Small-Diameter Lay-Flat Polyethylene Pipes
2016
[EN] The use of lay-flat polyethylene pipes to irrigate horticultural crops has been receiving widespread attention in the last decade, due to the significant improvements in their hydraulic performance, their potentially high application efficiency, and their limited installation costs. However, even if hydraulic design procedures for conventional microirrigation systems are fairly well established, there is still the need to know how different pipe-wall thicknesses of lay-flat pipes can affect the pipe geometry under different operating pressures as well as the related consequences on friction losses. This paper, after comparing two different procedures (caliper and photographic) to asses…
N-(2-PIRYDYLAMINO) METHYLENEBISPHOSPHONIC ACID AS A SOLE SOURCE OF A FUNGI FUSARIUM STRAINS GROWING
2016
The active substance of new herbicide generation is N-(2-pirydyloamino) methylenobisphosphonic acid. Two strains Fusarium culmorum CB3 and Fusarium oxysporum XVI, isolated from soil treated with examined substance, were chosen to investigation of using it as a sole source of phosphorus, nitrogen or carbon in the concentrations at 1.0 mM. Interactions between the dominating strains of fungi and N-(2-pirydyloamino) methylenobisphosphonic acid, mycelium growth rate, the spore germinate index, the level chemical changes of N-(2-pirydyloamino) methylenobisphosphonic acid and pH were investigated after cultivation in mineral medium and its modifications. The results of growth kinetics of the stud…
A new plant wide modelling approach for the reduction of greenhouse Gas emission from wastewater treatment plants
2017
Recent studies about greenhouse gas (GHG) emissions show that sewer collection systems and wastewater treatment plants (WWTPs) are anthropogenic GHG potential sources. Therefore, they contribute to the climate change and air pollution. This increasing interest towards climate change has led to the development of new tools for WWTP design and management. This paper presents the first results of a research project aiming at setting-up an innovative mathematical model platform for the design and management of WWTPs. More specifically, the study presents the project’s strategy aimed at setting-up a plant-wide mathematical model which can be used as a tool for reducing/controlling GHG from WWTP.…
Chromatography-mass spectrometry: Recent evolution and current trends in environmental science
2020
The coupling of chromatography to mass spectrometry has been a very important step in environmental science that has changed routine workflows opening a horizon of new and impressive possibilities. This hyphenated technique benefits from coupling as chromatography offers great separation power and comprises various techniques and mechanisms. In turn, chromatography exploits the identification capability of mass spectrometry and is able to provide nominal or exact mass charge ration (m/z) not only of the intact molecule but also of several characteristic fragments. The sensitivity, selectivity, specificity, and rapidity in chromatography–mass spectrometry make this technology highly powerful…