Search results for "drain"

The influence of the prior distribution on the uncertainty analysis assessment of an urban drainage stormwater quality model

2009

Dust inputs and bacteria influence dissolved organic matter in clear alpine lakes.

2011

6 páginas, 4 figuras.

2016

Rivers carry large amounts of dissolved organic matter (DOM) to the oceans thereby connecting terrestrial and marine element cycles. Photo-degradation in conjunction with microbial turnover is considered a major pathway by which terrigenous DOM is decomposed. To reveal globally relevant patterns behind this process, we performed photo-degradation experiments and year-long bio-assays on DOM from ten of the largest world rivers that collectively account for more than one-third of the fresh water discharge to the global ocean. We furthermore tested the hypothesis that the terrigenous component in deep ocean DOM may be far higher than biomarker studies suggest, because of the selective photoche…

Cerebrospinal Fluid Glucose and Lactate Levels After Subarachnoid Hemorrhage: A Multicenter Retrospective Study.

2019

BACKGROUND In patients with subarachnoid hemorrhage (SAH), abnormalities in glucose and lactate metabolism have been described using cerebral microdialysis. Glucose and lactate concentrations in cerebrospinal fluid (CSF) are more easily accessible, but scarce data are available in this setting. The aim of this study is to assess the relationship of CSF glucose and lactate with blood concentrations and with unfavorable neurological outcome after SAH. METHODS A retrospective cohort study was conducted in 5 European University intensive care units. Patients aged 18 years and above who were admitted after a nontraumatic SAH over a 4-year period (2011 to 2014) were included if they had an extern…

Assessing sediment connectivity in dendritic and parallel calanchi systems

2019

Abstract Calanchi, a type of Italian badlands created by a combination of water erosion processes and environmental constraints controlling their development, is a striking example of long-term landscape evolution. Sediment connectivity can be defined as the degree to which a system facilitates the fluxes of sediments through itself. The goal of this research is testing the use of simple morphometric variables for assessing sediment connectivity of calanchi landforms distinguishing between dendritic and parallel systems. For detecting the morphological characteristics controlling the sediment connectivity of calanchi basins, literature data (146 calanchi basins) and measurements carried out…

Uncertainty in environmental and hydrological mathematical modelling

2012

The current state of knowledge regarding uncertainties in urban drainage models is poor. This is in part due to the lack of clarity in the way model uncertainty analyses are conducted and how the results are presented and used. There is a need for a common terminology and a conceptual framework for describing and estimating uncertainties in urban drainage models. Practical tools for the assessment of model uncertainties for a range of urban drainage models are also required to be developed. This paper, produced by the International Working Group on Data and Models, which works under the IWA/IAHR Joint Committee on Urban Drainage, is a contribution to the development of a harmonised framewor…

Does Ligasure(TM) Reduce Fluid Drainage in Axillary Dissection? A Randomised Prospective Clinical Trial

2007

Background: Axillary lymph node dissection (ALND) is an integral part of breast cancer treatment. It is required in about 40–50% of patients. The placement of a drain in the axilla after an operation is current surgical practice. Short surgical stay programmes increase operating efficiency and reduce medical care costs, without compromising quality of care. LigaSureTM is a new haemostatic device that uses bipolar energy to seal vessels. The aim of this study is to determine whether axillary dissection with LigaSureTM reduces the time of wound drainage, the duration of surgical intervention and the volume of drainage after treatment. Patients and methods: This study is a prospective randomiz…

Catchment size and contribution of the largest daily events to suspended sediment load on a continental scale

2013

Abstract The classic approach defines an extreme event as a rare event identified by magnitude–frequency analysis and quantified by its deviation from a central value. They are key to understand geomorphological dynamics, since they are responsible for a considerable amount of work and “time compression”. Time compression means that most of the geomorphic work (particularly sediment transport) is produced in very short temporal intervals (i.e. in few events). Moreover, it is well known from magnitude–frequency analyses that events not necessarily extreme by magnitude could be responsible for a large amount of geomorphic work. To analyse the time compression of geomorphological processes, a …

Hydraulic conductivity and strength of pervious concrete for deep trench drains

2019

Abstract Pervious concrete for deep trench drains, used to stabilise slopes, must meet many requirements, namely, adequate hydraulic conductivity, adequate shear strength a few days after pouring, capacity to act as a protective filter for soils in which the drain is installed, good resistance to clogging and adequate residual hydraulic conductivity. In current engineering practice, the composition of pervious concrete for drains is improperly selected according to criteria used for no-fines concrete for road pavements. To detect more suitable and specific criteria, a laboratory investigation has been conducted aimed at identifying the composition and the properties of pervious concrete sat…

Long Term Efficiency Analysis of Infiltration Trenches Subjected to Clogging

2018

Abstract: In recent years, limitations linked to traditional urban drainage schemes have been pointed out and new approaches were developed introducing more natural methods for retaining and/or disposing of stormwater. Such practices include infiltration and storage tanks in order to reduce the peak flow and retain part of the polluting components. The impact of such practices on stormwater quantity and quality is not easily assessable because of the complexity of physical and chemical processes involved. In such cases, integrated urban drainage models may play a relevant role providing tools for long term analysis. In this study, the effect of the clogging phenomenon has been assessed by m…