scholarly journals A Note on One- and Three-Dimensional Infiltration Analysis from a Mini Disc Infiltrometer

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1783 ◽  
Author(s):  
George Kargas ◽  
Paraskevi Londra ◽  
Konstantinos Anastasiou ◽  
Petros Kerkides
Keyword(s):  
Shape Parameter ◽  
Sandy Loam ◽  
Three Dimensional ◽  
Silty Clay ◽  
Soil Hydraulic Properties ◽  
One Dimensional ◽  
Cumulative Infiltration ◽  
The Difference ◽  
Infiltration Tests ◽  
Disc Infiltrometer

Disc infiltrometers are used to characterize soil hydraulic properties. The purpose of this study was to determine the difference between three- and one-dimensional infiltration and to calculate the infiltration shape parameter γ from a proposed analytical infiltration equation. One- and three-dimensional infiltration tests were done on three repacked soils (loam, sandy loam, and silty clay loam) for two negative pressure heads. A mini disc infiltrometer of a radius of 22.5 mm with suction that ranged from −5 mm to −70 mm was used. The difference between experimental three- and one-dimensional cumulative infiltration was linear with time, which confirmed the proposed equation. In this study, the shape parameter γ seems not to be seriously affected by the soil type and acquires values from 0.561 to 0.615, i.e., smaller than the value γ = 0.75, which is widely used. With these values, the criteria proposed for calculating hydraulic conductivity using three-dimensional infiltration data may be fulfilled in most soils.

scholarly journals Investigation of the Relationship between Three- and One-Dimensional Infiltration Using a Mini Disc Infiltrometer

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 660
Author(s):  
George Kargas ◽  
Paraskevi Londra ◽  
Konstantinos Anastasiou
Keyword(s):  
Soil Analysis ◽  
Silty Clay ◽  
Clay Loam ◽  
Clay Loam Soil ◽  
Silty Clay Loam ◽  
One Dimensional ◽  
Loam Soil ◽  
The Difference ◽  
Disc Infiltrometer ◽  
The Relationship

Disc infiltrometer experiments were conducted in the laboratory on two disturbed soils, a loam and a silty clay loam soil, in order to investigate the relationship between three- and one-dimensional infiltration using the proposed equation of Smettem et al. A mini disc infiltrometer of a radius of 45 mm with suction ranged from −5 mm to −70 mm was used. Three- and one-dimensional infiltration tests were performed on repacked cores by applying pressure heads −70, −40 and −10 mm for loam soil, and −30 and −10 mm for silty clay loam soil. Analysis of the results showed that the difference between the three- and one-dimensional infiltration is linear with time confirming the equation of Smettem et al. [1]. Also, this difference is used to calculate the value of an additional infiltration parameter.

Theory of ultrasonic attenuation in one and two dimensional metals

1976 ◽  
Vol 54 (14) ◽  
pp. 1454-1460 ◽  
Author(s):  
T. Tiedje ◽  
R. R. Haering
Keyword(s):  
Ultrasonic Attenuation ◽  
Three Dimensional ◽  
Electronic Systems ◽  
Two Dimensional ◽  
Temperature Dependent ◽  
One Dimensional ◽  
The Difference

The theory of ultrasonic attenuation in metals is extended so that it applies to quasi one and two dimensional electronic systems. It is shown that the attenuation in such systems differs significantly from the well-known results for three dimensional systems. The difference is particularly marked for one dimensional systems, for which the attenuation is shown to be strongly temperature dependent.

Difference Solution to Chloride Diffusion in Concrete

2011 ◽  
Vol 99-100 ◽  
pp. 754-757
Author(s):  
Ai Ping Yu ◽  
Hai Bo Lu ◽  
Yan Lin Zhao ◽  
Ke Yu Wei
Keyword(s):  
Differential Equation ◽  
Discrete Model ◽  
Three Dimensional ◽  
Chloride Diffusion ◽  
Second Law ◽  
Continuous Variables ◽  
Convergence Conditions ◽  
One Dimensional ◽  
The Difference ◽  
2D And 3D

Fick’s second law and its analytical solution were usually used for analysis of chloride diffusion in concrete. But discretization of the continuous variables is more appropriate in modeling and discrete model is more suitable for engineering applications. In this paper, Difference Equation equivalent to partial differential equation was established with the difference method, and three-dimensional differential equation of Fick's second law was resolved. Based on this study，the convergence conditions of difference Equations for one-dimensional, 2D and 3D diffusion was given.

Numerical Project for the Undergraduate Heat Transfer Course

2017 ◽  
Author(s):  
Dani Fadda
Keyword(s):  
Heat Transfer ◽  
Solid Body ◽  
Three Dimensional ◽  
Engineering Curriculum ◽  
One Dimensional ◽  
Conduction Heat Transfer ◽  
Heat Transfer Simulation ◽  
The Difference ◽  
Dimensional Simulation ◽  
Classroom Time

A numerical simulation project, described in this paper, was assigned in an undergraduate heat transfer course in the mechanical engineering curriculum. This project complemented the heat transfer lecture course and its corresponding heat transfer lab. It was used to help students visualize and better understand the difference between conduction heat transfer which occurs within a three-dimensional solid body and the convection and/or radiation which occur at the surface of the solid body. It also allowed the students to generate and compare results of one dimensional heat transfer calculations to three dimensional simulation results. The project contained well defined deliverables and an open-ended deliverable which allowed students to be creative. It gave the students reason to discuss the course outside the classroom. It allowed students to use SolidWorks heat transfer simulation and manage a MATLAB script without taking classroom time. It was appreciated and enjoyed by the students.

Conductivity relaxation in the interfacial phase of iron core–iron oxide shell nanocomposites

2006 ◽  
Vol 21 (7) ◽  
pp. 1704-1711 ◽  
Author(s):  
S. Basu ◽  
J.R. Macdonald ◽  
D. Chakravorty
Keyword(s):  
Dielectric Constant ◽  
Shape Parameter ◽  
Three Dimensional ◽  
Oxide Shell ◽  
Iron Core ◽  
Parameter Estimates ◽  
Two Dimensional ◽  
Charge Motion ◽  
Electrical Measurements ◽  
One Dimensional

The alternating current electrical conductivity of a gel-derived glass of composition 55Fe2O3⋅45SiO2 (mol%) was measured over a frequency range of 100 Hz to 6 MHz. The gel was subjected to a reduction treatment at 923 K for ½ h and subsequently heated in ordinary atmosphere at a temperature 773 K for ½ h to grow a Fe-core Fe3O4 shell nanostructure with a median diameter of 6.2 nm. This formed a percolative network within the silica gel. Mossbauer spectra confirmed the presence of Fe3O4 in the nanoshell. Electrical measurements were also carried out on these nanocomposites at different frequencies and temperatures. Isothermal electrical modulus data for both reference and treated glass systems were analyzed using both the CK0 and CK1 Kohlrausch-related frequency response models. Reference-glass shape parameter values, estimated by fitting the experimental data to the K0 model at several temperatures, were found to be ∼0.32. Here, the K0 model led to much better fits than the K1 did. However, for the treated core–shell-structured nanocomposite material, both models yielded good fits with consistent but different shape parameter estimates: very close to ½ for the K0 model and ⅓ for the K1 model. In accordance with the structural measurements and with axiomatic topological considerations that predict a shape-parameter value of ⅓ for one-dimensional motion and ½ for two-dimensional motion, it appears that the ∼0.32 value is consistent with one-dimensional motion of charge carriers along the narrow channels of the interconnected iron-rich three-dimensional phase of the reference glass. Further, although the K1-model ⅓ estimates for the treated material also indicate the presence of one-dimensional charge motion at the two-dimensional interface between the two interconnected phases of the reference glass, the ½ K0 estimates for the same material suggest an effective charge-motion dimension of 2. Importantly, comparison of the high-frequency dielectric constant estimates for the K0 reference glass and the K1 treated one clearly leads to the new but physically plausible conclusion that the bulk frequency-independent dielectric constant of about 30 is independent of the treatment.

scholarly journals The Influence of Different Technologies of Soil Processing on Infiltration Properties of Soil in the Cambisols Area of the Opava District

2016 ◽  
Vol 64 (5) ◽  
pp. 1495-1505
Author(s):  
Miroslav Dumbrovský ◽  
Lucie Larišová
Keyword(s):  
Hydraulic Conductivity ◽  
Clayey Soil ◽  
Spring Barley ◽  
Arable Land ◽  
Conventional Tillage ◽  
Reduced Tillage ◽  
Unsaturated Hydraulic Conductivity ◽  
Cumulative Infiltration ◽  
Infiltration Tests ◽  
Disc Infiltrometer

The subject of the contribution is the evaluation of the influence of the conventional tillage and reduced tillage technology of soil processing on the infiltration properties of the soil in the Větřkovice area. Field experimental work at the area was carried out in the years 2013–2015 on Cambisol district medium-heavy clayey soil. The research was conducted on sloping erosion-endangered blocks of arable land sown with spring barley. The areas were chosen each year in the way that one of the experimental areas was handled by conventional tillage technologies and the other by reduced tillage technologies. Intact soil samples were taken into Kopecký’s cylinders in the three landscape positions, at a depth of 10 cm (representing topsoil) and 30 cm (representing subsoil). The cumulative infiltration was measured using a mini-disc infiltrometer near the consumption points. The Zhang method (1997), which provides an estimate of the unsaturated hydraulic conductivity K(h), was used for the evaluation of the infiltration tests of the mini-disc infiltrometer. The soil profile processed by conventional tillage showed a higher degree of compaction. The bulk density was between 1.10–1.67 g.cm-3, compared to the land processed by the reduced tillage technology, where the values were between 0.80–1.29 g.cm-3. Unsaturated hydraulic conductivity values were about one‑third higher within the reduced tillage technology soil processing.

EFFECTS OF pH AND NITRIFIER POPULATION ON NITRIFICATION OF BAND-APPLIED AND HOMOGENEOUSLY MIXED UREA NITROGEN IN SOILS

1975 ◽  
Vol 55 (1) ◽  
pp. 15-21 ◽  
Author(s):  
P. C. PANG ◽  
C. M. CHO ◽  
R. A. HEDLIN
Keyword(s):  
Soil Ph ◽  
Sandy Loam ◽  
Silty Clay ◽  
Clay Loam ◽  
Nitrate Accumulation ◽  
Soil Suspension ◽  
Soil Nitrification ◽  
Ph Values ◽  
Effects Of Ph ◽  
The Difference

Two soils, Keld silty clay loam (pH 5.4) and Wellwood clay loam (pH 6.6), were used to investigate the effects of modifying soil pH upon the nitrification of band-applied urea at 20 C. The pH of the Keld soil was adjusted to 6.5 and 7.3 with Ca (OH)2, whereas the Wellwood soil was adjusted to 5.6 with H2SO4. In addition, nitrification of nitrogen in a homogeneously mixed soil–urea suspension at 20 C was studied using the two soils mentioned and also Morton very fine sandy loam (pH 8.2). There were marked differences in the rate of oxidation of NH4 between the natural Keld and acidified Wellwood soils at comparable soil pH values. The oxidation was found to be very slow in the Keld soil at all pH values and no appreciable nitrite was formed. In the Wellwood soil, nitrification was more rapid and was accompanied by nitrite formation. However, the rate of oxidation was temporarily retarded by decreasing the pH of the Wellwood soil, but the oxidation of band-applied urea in the Keld soil remained unchanged with modified pH of 6.5 and 7.3. Increase in nitrification and nitrate accumulation occurred when the limed Keld soils (pH 7.3) was inoculated with Nitrosomonas europaea. Soil suspension studies confirmed that the difference in nitrifying capacity among the soils was related to the initial nitrifier numbers whose activities were affected by the initial soil pH.

The coordination chemistry of two symmetric fluorene-based organic ligands with cuprous chloride

2013 ◽  
Vol 69 (12) ◽  
pp. 1488-1493 ◽  
Author(s):  
Yan-Fei Liu ◽  
Chao-Wei Zhao ◽  
Jian-Ping Ma ◽  
Qi-Kui Liu ◽  
Yu-Bin Dong
Keyword(s):  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Helical Chain ◽  
Cuprous Chloride ◽  
Dimensional Chain ◽  
Two Dimensional ◽  
One Dimensional ◽  
Dimensional Network ◽  
The Difference ◽  
The One

Two novel symmetric fluorene-based ligands, namely, 2,7-bis(1H-imidazol-1-yl)-9,9-dimethyl-9H-fluorene [L1 or (I), C21H18N4] and 2,7-bis(1H-imidazol-1-yl)-9,9-dipropyl-9H-fluorene (L2), have been used to construct the coordination polymerscatena-poly[[dichloridodicopper(I)(Cu—Cu)]-μ-2,7-bis(1H-imidazol-1-yl)-9,9-dimethyl-9H-fluorene], [Cu2Cl2(C21H18N4)]n, (II), andcatena-poly[[tetra-μ2-chlorido-tetracopper(I)]-bis[μ-2,7-bis(1H-imidazol-1-yl)-9,9-dipropyl-9H-fluorene]], [Cu4Cl4(C25H26N4)2]n, (III). There are three types of C—H...N hydrogen bonds in (I), resulting a two-dimensional network in theabplane, including a chiral helical chain along thebaxis. Compounds (II) and (III) are related one-dimensional polymers. In both, CuIatoms connect the symmetric ligands (L1 orL2) into a one-dimensional chain. In (II), the {[CuICl2]−} unit, acting as a co-anion, adheres to the one-dimensional chain through a weak Cu...Cu interaction. However, in (III), the {[CuI2Cl4]2−} unit links two different chains into a one-dimensional rope-ladder-type chain. In addition, there are C—H...Cl hydrogen bonds and π–π interactions in the extended structures of (II) and (III), the difference is that the chains in (II) are linked into a two-dimensional network while the chains in (III) are stacked into a three-dimensional framework.

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