scholarly journals Comment on “Shape factors for constant-head double-packer permeameters” by S. A. Mathias and A. P. Butler

2008 ◽  
Vol 44 (7) ◽  
Author(s):  
Robert P. Chapuis ◽  
Djaouida Chenaf
Keyword(s):  
Shape Factors ◽  
Constant Head

A constant-head well permeameter method for measuring field-saturated hydraulic conductivity above an impermeable layer

2004 ◽  
Vol 84 (3) ◽  
pp. 255-264 ◽  
Author(s):  
Masaki Hayashi ◽  
William L. Quinton
Keyword(s):  
Hydraulic Conductivity ◽  
Weighted Average ◽  
Saturated Hydraulic Conductivity ◽  
Shape Factors ◽  
Promising Tool ◽  
Northern Regions ◽  
Measuring Field ◽  
Impermeable Layer ◽  
Constant Head ◽  
Guelph Permeameter

Hydrologic understanding of mountainous and northern regions of Canada is poor owing to the lack of critical field data such as hydraulic conductivity. A portable field instrument, the Guelph permeameter (GP), is a promising tool for measuring field-saturated hydraulic conductivity in remote watersheds inaccessible by motorized vehicles. In order to extend the applicability of the GP method to relatively thin soils underlain by impermeable bedrock or permafrost, a new set of shape factors was determined by numerical simulation. The new shape factors gave accurate values of field-saturated hydraulic conductivity when tested in the laboratory. The impermeable layer causes flow around the auger hole to be primarily horizontal. Therefore, the GP method measures a predominantly horizontal field-saturated hydraulic conductivity in these thin soils. The measured conductivity represents a weighted average of the soil surrounding the submerged surface of the auger hole. In layered soil, the weight is greater for the layers close to the bottom of the hole than for those close to the top. Key words: Guelph permeameter, hydraulic conductivity, forest hydrology, permafrost, peat

scholarly journals A Preliminary Study on a Pumping Well Capturing Groundwater in an Unconfined Aquifer with Mountain-Front Recharge from Segmental Inflow

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1243
Author(s):  
Haixiang Li ◽  
Xu-sheng Wang
Keyword(s):  
Water Supply ◽  
Unconfined Aquifer ◽  
Shape Factors ◽  
Unconfined Aquifers ◽  
Capture Zones ◽  
Pumping Wells ◽  
Travel Time Distribution ◽  
Mountain Front ◽  
Constant Head ◽  
A Site

Unconfined aquifers beneath piedmont pluvial fans are widely distributed in front of mountains and proper for water supply with pumping wells. However, the catchment zone and capture zones of a pumping well in such an unconfined aquifer is not well known. We develop a preliminary simplified model where groundwater flows between a segmental inflow boundary and a discharge boundary of constant head. The catchment zone is delineated from numerical simulation via MODFLOW and MODPATH. Results are expressed with dimensionless variables and lumped parameters to show general behaviors. Sensitive analyses indicate that there are 4 types of the catchment zone according to different connections to the boundaries. The shape of the catchment zone is quantitatively analyzed with typical shape factors. Capture zones with respect to special travel times are identified from travel time distribution in the catchment zone. The modeling results can be applied in the design of water supply wells and delineation of protection zones at a site with similar hydrogeological conditions.

Effects of Inclination Angle on Archimedes Screw Generator Power Production with Constant Head

2021 ◽  
Vol 147 (3) ◽  
pp. 04021001
Author(s):  
Scott Simmons ◽  
Guilhem Dellinger ◽  
Murray Lyons ◽  
Abdelali Terfous ◽  
Abdellah Ghenaim ◽  
...  
Keyword(s):  
Inclination Angle ◽  
Power Production ◽  
Constant Head

Comparison of copper sulphate pentahydrate growth rates determined by different methods

1990 ◽  
Vol 55 (7) ◽  
pp. 1691-1707 ◽  
Author(s):  
Miloslav Karel ◽  
Jiří Hostomský ◽  
Jaroslav Nývlt ◽  
Axel König
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Fluidized Bed ◽  
Growth Rates ◽  
Copper Sulphate ◽  
Crystal Growth Rate ◽  
Effect Of Temperature ◽  
Rotating Disc ◽  
Shape Factors ◽  
Data Treatment

Crystal growth rates of copper sulphate pentahydrate (CuSO4.5 H2O) determined by different authors and methods are compared. The methods included in this comparison are: (i) Measurement on a fixed crystal suspended in a streaming solution, (ii) measurement on a rotating disc, (iii) measurement in a fluidized bed, (iv) measurement in an agitated suspension. The comparison involves critical estimation of the supersaturation used in measurements, of shape factors used for data treatment and a correction for the effect of temperature. Conclusions are drawn for the choice of values to be specified when data of crystal growth rate measurements are published.

scholarly journals The Impact of Filler Geometry on Polylactic Acid-Based Sustainable Polymer Composites

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 149
Author(s):  
Karol Leluk ◽  
Stanisław Frąckowiak ◽  
Joanna Ludwiczak ◽  
Tomasz Rydzkowski ◽  
Vijay Kumar Thakur
Keyword(s):  
Polymer Composites ◽  
Polylactic Acid ◽  
Matrix Material ◽  
Chemical Properties ◽  
Precipitated Calcium Carbonate ◽  
Cellulose Fibres ◽  
Shape Factors ◽  
Pure Cellulose ◽  
Physico Chemical ◽  
The Impact

Recently, biocomposites have emerged as materials of great interest to the scientists and industry around the globe. Among various polymers, polylactic acid (PLA) is a popular matrix material with high potential for advanced applications. Various particulate materials and nanoparticles have been used as the filler in PLA based matrix. One of the extensively studied filler is cellulose. However, cellulose fibres, due to their hydrophilic nature, are difficult to blend with a hydrophobic polymer matrix. This leads to agglomeration and creates voids, reducing the mechanical strength of the resulting composite. Moreover, the role of the various forms of pure cellulose and its particle shape factors has not been analyzed in most of the current literature. Therefore, in this work, materials of various shapes and shape factors were selected as fillers for the production of polymer composites using Polylactic acid as a matrix to fill this knowledge gap. In particular, pure cellulose fibres (three types with different elongation coefficient) and two mineral nanocomponents: precipitated calcium carbonate and montmorillonite were used. The composites were prepared by a melt blending process using two different levels of fillers: 5% and 30%. Then, the analysis of their thermomechanical and physico-chemical properties was carried out. The obtained results were presented graphically and discussed in terms of their shape and degree of filling.

Virus transport from drywells under constant head conditions: A modeling study

2021 ◽  
Vol 197 ◽  
pp. 117040
Author(s):  
Salini Sasidharan ◽  
Scott A. Bradford ◽  
Jiří Šimůnek ◽  
Stephen R. Kraemer
Keyword(s):  
Virus Transport ◽  
Constant Head ◽  
Modeling Study
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