Changes in Predicted Peak Discharges in Pennsylvania as a Result of Using the Proposed Cerrelli Curves for the Shallow Concentrated Flow Portion in the NRCS Velocity Based Time of Concentration Method

2009 ◽  
Author(s):  
Geoffrey A Cerrelli
Keyword(s):  
Time Of Concentration ◽  
Concentrated Flow ◽  
Concentration Method ◽  
Peak Discharges

scholarly journals Calculation of time of concentration for hydrologic design and analysis using geographic information system vector objects

2002 ◽  
Vol 4 (2) ◽  
pp. 75-81 ◽  
Author(s):  
Jonathan I. Green ◽  
E. James Nelson
Keyword(s):  
Lag Time ◽  
Flow Path ◽  
Specific Flow ◽  
Analysis And Design ◽  
Time Of Concentration ◽  
Concentrated Flow ◽  
Hydrologic Analysis ◽  
Two Parameters ◽  
Unit Hydrographs ◽  
Hydrologic Design

Synthetic unit hydrographs are commonly used to estimate runoff from rainfall events in a hydrologic analysis. A key parameter required as part of any hydrologic analysis using a synthetic unit hydrograph is time of concentration or lag time. Generally, equations used to compute time of concentration or lag time are empirically derived from basin parameters such as area, slope, and a specific flow path length. A more realistic method for determination of flow path travel time is to divide the flow path according to different hydraulic conditions such as sheet flow, shallow concentrated flow and open channel flow as specified in the NRCS method using TR55. Such equations are all based on flow length and the slope of the flow path, two parameters that are easily calculated from GIS vector objects. A method is presented that uses GIS vector objects with equations assigned for the calculation of time of concentration or lag time for use in hydrologic analysis and design.

Cytochemical Specializations on the Luminal Surface of Blood Vessels in the Developing Rat Central Nervous System

1975 ◽  
Vol 33 ◽  
pp. 462-463
Author(s):  
R. S. Hannah ◽  
T. H. Rosenquist
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Blood Vessels ◽  
Alcian Blue ◽  
Luminal Surface ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Concentration Method ◽  
Endothelial Surface ◽  
Cacodylate Buffer

Developing blood vessels in the rat central nervous system exhibit several unusual luminal features. Hannah (1975) used high voltage electron microscopy to demonstrate numerous ridges of endothelium, some near junctional complexes. The ridges produced troughs (which may appear as depressions) in the endothelial surface. In some areas ridges extended over the troughs, removing them from direct contact with the luminal surface. At no time were the troughs observed to penetrate the basal laminae. Fingerlike projections also extended into the lumina.To determine whether any chemical specializations accompanied the unusual morphological features of the luminal surface, we added 0.1% Alcian blue (Behnke and Zelander, 1970) to the 3% glutaraldehyde perfusate (cacodylate buffer, pH 7.4). After Alcian blue had reacted with the luminal glycocalyces, the dye was dissociated with MgCl2 via critical electrolyte concentration method of Scott and Dorling (1965). When these methods are applied together, it is possible to differentiate mucopolysaccharides (glycosaminoglycans or GAG) with the electron microscope.

Formation of water chemistry in the Modonkul river under the action of mine drainage effluent

2020 ◽  
pp. 56-66
Author(s):  
Z. I. Khazheeva ◽  
S. S. Sanzhanova
Keyword(s):  
Water Chemistry ◽  
Mine Drainage ◽  
High Concentration ◽  
Catchment Basin ◽  
Sulfate Anion ◽  
Concentrated Flow ◽  
Sodium Calcium ◽  
Calcium Cation ◽  
Calcium Magnesium ◽  
The Town

The Dzhida ore field in the Zakamensk district of Buryatia features high concentration of mineralization within a small area. The Dzhida deposit is composed of complex ore. The ore field contains commercial-value primary deposits: Pervomai stockwork of molybdenum, Kholtoson tungsten lode and Inkur stockwork of tungsten. The Modonkul river catchment basin lies inside the Dzhida ore field. A real threat to the town of Zakamensk is created by manmade sand-bulk (old) tailings and slurry dump. By now, the concentrated flow of natural and man-made sand enters the low terrace and floodplain of the Modonkul river in the form of a talus train. This study is focused on the influence of the mine drainage effluent and the Inkur tributary on the water chemistry in the Modonkul river. 80 water samples were taken from the surface layer 0-0.5 m thick at five stations. Physicochemical indices of water were measured at the water sampling points, and the water chemistry was analyzed in a laboratory. In the background conditions, cations and anions in the Modonkul water chemistry range in decreasing order as follows: Са2+ > Mg2+ > Na++К+ и HCO - > SO 2- > Cl-. In the zone of mixture of natural and mine process water, the chemistry changes: from hydrocarbonate to sulfate (anion), from calcium-magnesium to sodium-calcium (cation). Downstream the natural chemistry changes to the hydrocabonate-sulfate composition, with prevailing content of calcium in cations. Iron content of water lowers 3-4 times after influx of mine effluents, while the contents of Mn, Zn, Co and Cd grow and then decrease downstream.

INVESTIGATIONOF CONCENTRATION METHOD OF SCANDIUM-CONTAINING SOLUTIONS

2019 ◽  
Vol 6 (438) ◽  
pp. 12-20
Author(s):  
Nikolai Sergeevich Ivanov ◽  
◽  
Nurlan Maratovich Shokobayev ◽  
Iskander Yersayanovich Adelbayev ◽  
Arlan Zainutallaevich Abilmagzhanov ◽  
...  
Keyword(s):  
Concentration Method

Simultaneous and Sensitive Determination of Amphetamine, Codeine and Morphine in Exhaled Breath Condensate, Using Capillary Electrophoresis Coupled with On-line and Off-line Enhancing Methods

2020 ◽  
Vol 16 (7) ◽  
pp. 872-879
Author(s):  
Samin Hamidi
Keyword(s):  
Drugs Of Abuse ◽  
Exhaled Breath Condensate ◽  
Direct Injection ◽  
Forensic Toxicology ◽  
Analytical Signal ◽  
Exhaled Breath ◽  
Concentration Method ◽  
Validation Parameters ◽  
Breath Condensate

Background: Abuse of drugs is associated with several medical, forensic, toxicology and social challenges. “Drugs of abuse” testing is therefore an important issue. Objective: We propose a simple CE-based method for the quantification of amphetamine, codeine and morphine after direct injection of Exhaled Breath Condensate (EBC) by the aid of simple stacking mode and an off-line pre-concentration method. Methods: Using graphene oxide adsorbents, amphetamine, codeine and morphine were extracted from EBC in order to eliminate the proteins and other interferences. In addition to off-line method, an online stacking mode was applied to improve the analytical signal obtained from the instrument. Results: The validation parameters were experimented on the developed method based on the FDA guideline over concentration ranges of 12.5-100, 30-500 and 10-1250 ng/mL associated with amphetamine, codeine and morphine, respectively. Small volumes (around 100 μL) of EBC were collected using a lab-made setup and successfully analyzed using the proposed method where precisions and accuracies (within day and between days) were in accordance with the guideline (recommended less than 15 % for biological samples). The recovery tests were used to evaluate the matrix effect and data (94 to 105 %) showed that the proposed method can be applied in different EBC matrix samplings of subjects. Conclusion: The proposed method is superior for simultaneous determination of amphetamine, codeine and morphine over chromatographic analyses because it is fast and consumes fewer chemicals, with no derivatization step.

Effects of grass roots on the erodibility of topsoils during concentrated flow

Geomorphology ◽  
2006 ◽  
Vol 76 (1-2) ◽  
pp. 54-67 ◽  
Author(s):  
S. De Baets ◽  
J. Poesen ◽  
G. Gyssels ◽  
A. Knapen
Keyword(s):  
Concentrated Flow ◽  
Grass Roots
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