scholarly journals The Capillary Rise in Fine and Coarse-Grained Soils Considering the Matric Suction

2021 ◽  
Author(s):  
Jair Arrieta Baldovino ◽  
Ronaldo Izzo ◽  
Carlos Millan-Paramo
Keyword(s):  
Soil Column ◽  
Capillary Rise ◽  
Experimental Studies ◽  
Matric Suction ◽  
Coarse Grained ◽  
Column Height ◽  
Maximum Height ◽  
Rise Velocity ◽  
Unsaturated Hydraulic Conductivity ◽  
Time Required

Abstract Few pieces of research have been conducted on the phenomenon of capillary rise in the field of soil for agriculture and geotechnical engineering. The rate of capillary rise of water in fine and granular soil is one of the major challenges for rising experiments in vertical open-tubes, as the time required for the water to reach the maximum height of capillary rise (hc) can vary from 50 to 400 days. The control variables during the capillary experiment are mainly: saturated and unsaturated hydraulic conductivity, soil density, water content, soil column height, and velocity of capillary rise. Thus, this paper presents theoretical and experimental studies of capillary rise in several soils based on matric suction models. Results were gathered by comparing the behavior of capillary rise using the analytical solutions developed by Lu (2016), Lu and Likos (2004), and by Terzaghi (1943). On analysis of the results, it was concluded that the equation proposed by Lu and Likos (2004) is the most suitable to predict the capillary rise velocity for the fine-coarse soils and the equation proposed by Lu (2016) is more suitable to predict the matric suction. Other mathematical model developed by Liu et al. (2014) is also suitable to estimate the hc but don’t consider the velocity of the water. The capillary rise method to measure the matric suction must be more applicable in sandy soil than clayey soils.

Preventing surface deposition of chromium with asphalt caps at chromite ore processing residue sites: a case study

2007 ◽  
Vol 44 (7) ◽  
pp. 814-839 ◽  
Author(s):  
Karen S Henry ◽  
John C Petura ◽  
Steven Brooks ◽  
Steven Dentico ◽  
Stephen A Kessel ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Capillary Rise ◽  
Matric Suction ◽  
Upward Movement ◽  
Chromite Ore Processing Residue ◽  
Chromite Ore ◽  
Ore Processing ◽  
Unsaturated Hydraulic Conductivity ◽  
Water Rise

Caps were constructed on chromite ore processing residue (COPR) sites in the Kearny, New Jersey, area between 1989 and 1994 to prevent human exposure to hexavalent chromium (Cr(VI)). The caps comprise geotextile overlain by 100 mm of dense graded aggregate (DGA) and 100 mm of hot mix asphalt (HMA). Prior to constructing these "composite asphalt caps" (CACs), Cr(VI) was sometimes deposited on surface soils as chromate (salts) during evaporative periods. We initially thought the geotextile and DGA acted as a capillary barrier, stopping capillary water rise, but site inspection revealed that the DGA and geotextile were too moist to perform this function. Further study included a literature review, DGA capillary rise estimates, in situ measurement of soil-water content over 7 months at a representative COPR site, and numerical modeling of matric suction gradients induced by evaporation. The collective results reveal that the CACs eliminate upward matric suction gradients from the COPR–soil through the DGA, thereby precluding surface chromate deposition. Even during evaporative periods, the low unsaturated hydraulic conductivity of the HMA restricts upward movement of moisture and soluble chromate from underlying COPR–soil. In contrast, there are almost always upward matric suction gradients in uncapped COPR–soil.Key words: capillary rise, chromite ore processing residue, chromate, hexavalent chromium, composite asphalt cap, evaporation.

Cooling of Fruit with Arbitrary Shape: Simulation Using Galerkin-Based Integral Method

2017 ◽  
Vol 10 ◽  
pp. 1-15
Author(s):  
P. Morais Pessôa ◽  
A.G. Barbosa de Lima ◽  
R. Swarnakar ◽  
J.P. Gomes ◽  
W.M.P. Barbosa de Lima
Keyword(s):  
Integral Method ◽  
Arbitrary Shape ◽  
Heat Conduction Equation ◽  
Low Cost ◽  
Experimental Studies ◽  
Volume Ratio ◽  
Transient Heat Conduction ◽  
Cooling Time ◽  
Time Required ◽  
Kinetics Of

Cooling has been used for the preservation of fresh produce such as fruit and vegetables due to its low cost and high effectiveness in maintaining the product quality. Recently, several researchers have conducted theoretical and experimental studies for obtaining the kinetics of cooling and cooling time for fruits with different geometries. Present work, therefore, aims to simulate the cooling of fruits with particular reference to banana, orange, strawberry and Tahiti lemon. The transient heat conduction equation and its analytical solution using Galerkin based integral method are presented. It has been found that the strawberry has lower dimensionless cooling time compared with time required to cool other fruits, which is due to its higher surface area/volume ratio value. In orange and lemon the temperature distribution was found to be homogeneous in the angular direction, while in banana and strawberry it was two-dimensional due to shape of the fruits.

Pretreatment processes for membrane filtration of raw water containing manganese

2001 ◽  
Vol 1 (5-6) ◽  
pp. 341-348 ◽  
Author(s):  
S. Takizawa ◽  
L. Fu ◽  
N. Pradhan ◽  
T. Ike ◽  
M. Ohtaki ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Manganese Concentration ◽  
Fluidised Bed ◽  
Raw Water ◽  
Biological Pretreatment ◽  
Manganese Removal ◽  
Time Required

Experimental studies on chemical and biological pretreatments in membrane filtration processes were carried out to removal manganese contained in raw water and to prevent membrane fouling due to manganese. Two types of the pretreatment reactors, i.e. the fluidised-bed and fixed-bed configurations, were compared in the biological pretreatment experiments. New synthetic media (tubular polypropylene, I.D. 3 mm, O.D. 4 mm, length 5 mm) were used in all three experiments as a manganese-oxidising catalyst. The chemical pretreatment using sodium hypochlorite was effective in manganese removal and controlling membrane fouling; more than 0.8 mg-Cl2/L of chlorine dose was necessary to bring the manganese concentration from 0.4 mg/L in raw water to less than 0.05 mg/L. The biological pretreatment for manganese removal required a long start-up period of more than 40 days. The fixed-bed biological pretreatment was superior in manganese removal and in control of membrane fouling to the fluidised-bed biological pretreatment, which showed wash-out of the attached bacteria resulting in membrane fouling. The linear velocity and the empty-bed retention time required for the treatment of 0.14 mg-Mn/L in the fixed-bed biological pretreatment was 206 m/d and 8.0 minutes, respectively.

Dynamic Behavior and Design of Offshore Caissons

1978 ◽  
Vol 18 (05) ◽  
pp. 291-299
Author(s):  
S.T. Hong ◽  
J.C. Brooks
Keyword(s):  
Dynamic Behavior ◽  
Experimental Studies ◽  
Design Procedure ◽  
Operational Experience ◽  
Dynamic Effects ◽  
Free Standing ◽  
Well Production ◽  
Single Well ◽  
Time Required ◽  
Short Time

Abstract Free-standing caissons are used for supporting flare pipes and single-well production platforms. However, caissons tend to be flexible and dynamically sensitive, and the static design practice may not be adequate for this type of practice may not be adequate for this type of structure. To assess motion effect on the integrity of the structural system and to quantify the allowable motion for safe operation on board a caisson platform, analytical and experimental studies of platform, analytical and experimental studies of the dynamic behavior of a caisson structure were conducted and are described here. The analytical simulations agree well statistically with The motion measurements. A caisson design procedure considering dynamic effects was developed Design considerations include ultimate strength failure, fatigue failure, excessive motion, and possible damage during installation. A key feature in an effective caisson design is that the upper part of the caisson should be made as small as possible so that wave loading and the caisson period can be minimized The fatigue design procedure was verified with past caisson operational experience. To illustrate past caisson operational experience. To illustrate the procedure, a flare-pipe support caisson in 185 ft of water was designed and analyzed. Introduction Free-standing caissons are used for supporting flare pipes or single-well production platforms. The attractiveness of a caisson structure lies in the potential economy and the short time required for potential economy and the short time required for fabrication and installation. However, a caisson tends to be flexible, and dynamic effects may increase the design requirements from both strength and functional standpoints. To assess the motion effect on the integrity of the structural system and to quantify the allowable motion level for effective operation on board a caisson platform, analytical and experimental studies of the dynamic behavior of a caisson structure were conducted, and a procedure was formulated for designing a caisson considering dynamic effects. Observations from the experimental data and computer simulations of the caisson behavior are described. Verification of the computer simulation and some useful information for developing and using such simulations as well as practical interpretation of the analytical results practical interpretation of the analytical results also are given. Differences between a static design and a dynamic design are illustrated in an example design of a flare-support caisson in 185 ft water. MOTION MEASUREMENT Motion data were taken from a caisson platform offshore Louisiana. General dimensions of the caisson are shown in Fig. 1. SPEJ P. 291

scholarly journals Length of Mucin-Like Domains Enhance Cell-Ebola Virus Adhesion by Increasing Binding Probability

2020 ◽  
Author(s):  
X. Cui ◽  
N. Lapinski ◽  
X. Zhang ◽  
A. Jagota
Keyword(s):  
Ebola Virus ◽  
Molecular Model ◽  
Persistence Length ◽  
Experimental Studies ◽  
Coarse Grained ◽  
Physiological Processes ◽  
Initial Adhesion ◽  
Binding Probability ◽  
A Cell ◽  
Coated Surface

AbstractThe Ebola virus (EBOV) hijacks normal physiological processes by apoptotic mimicry in order to be taken up by the cell it infects. The initial adhesion of the virus to the cell is based on the interaction between T-cell immunoglobulin and mucin domain protein, TIM, on the cell-surface and phosphatidylserine (PS) on the viral outer surface. Therefore, it is important to understand the interaction between EBOV/PS and TIM, with selective blocking of the interaction as a potential therapy. Recent experimental studies have shown that for TIM-dependent EBOV entry, a Mucin-like Domain (MLD) with a length of at least 120 amino acids is required, possibly due to the increase of area of the PS-coated surface sampled. We examine this hypothesis by modeling the process of TIM-PS adhesion using a coarse-grained molecular model. We find that the strength of bound PS−TIM pairs is essentially independent of TIM length. TIMs with longer MLDs have higher average binding strengths because of an increase in the probability of binding between EBOV and TIM proteins. Similarly, we find that for larger persistence length (less flexible) the average binding force decreases, again because of a reduction in the probability of binding.Statement of SignificanceThis work studies the mechanism of TIM-dependent adhesion of the Ebola virus to a cell. Through coarse grained modeling we show that longer TIM stalks adhere more easily as they can sample a larger area, thus offering a mechanistic interpretation of an experimental finding. Better mechanistic understanding can lead to therapeutic ideas for blocking adhesion.

scholarly journals Effects of droplet size and surfactants on anchoring in liquid crystal nanodroplets

Soft Matter ◽  
2019 ◽  
Vol 15 (19) ◽  
pp. 3914-3922 ◽  
Author(s):  
Zeynep Sumer ◽  
Alberto Striolo
Keyword(s):  
Phase Diagram ◽  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Droplet Size ◽  
Experimental Studies ◽  
Coarse Grained ◽  
Coarse Grained Simulations

In an attempt to bridge the gap between computational and experimental studies, coarse-grained simulations are used to study nematic Liquid Crystal (LC) nanodroplets dispersed in water. A LC phase diagram is generated as a function of droplet size and temperature, and the effect of adding surfactants is quantified.

scholarly journals Study on the Microscopic Characteristics of Ferruginous cement of Banguo Earth Forest in Yuan mou area, Yunnan, China

2019 ◽  
Vol 23 (3) ◽  
pp. 191-198
Author(s):  
Penghui Luo ◽  
Shitao Zhang ◽  
Yimin Tian ◽  
Fei Ding ◽  
Zongming Xu
Keyword(s):  
Spatial Structure ◽  
Clay Minerals ◽  
Yunnan Province ◽  
Soil Column ◽  
Mechanical Tests ◽  
The Self ◽  
Column Height ◽  
Curing Agent ◽  
Iron Compounds ◽  
Dispersed Particles

The column height of earth forest is generally 8~30m in yuanmou county of yunnan province, which is far higher than the self-supporting height of general soil column. Ferruginous cement is an important reason for formation of the tall and erect columnar soil. Macroscopic physical and mechanical tests confirmed that the strength of the stratum containing ferruginous cement was much higher than that of the formation without ferruginous cement. The microstructure and morphology of ferruginous cement were analyzed by SEM and EDS. It is found that ferruginous cement is mainly composed of iron compounds and clay minerals, which only exists in certain stratum. In the process of growth, Iron compounds chemically bond with clay minerals during growth to form ferruginous cements, which first form unique sphere on the surface of particles or clay minerals. It then clumps together and fills the spaces between the particles. Finally, the dispersed particles are connected together to form a stable lamellar spatial structure, which greatly improves the strength of the soil. Through the study of ferruginous cement, the mechanism of this natural curing agent is understood, which enriches the research content in this field.

Experimental studies of the influence of technological heredity on the damage to wheels of high hardness

2020 ◽  
pp. 12-14
Author(s):  
M.I. Biserikan ◽  
S.V. Petrochenko ◽  
K.V. Averkov ◽  
A.A. Rauba
Keyword(s):  
Experimental Data ◽  
Experimental Studies ◽  
Contact Fatigue ◽  
High Hardness ◽  
The State ◽  
Maximum Height ◽  
Technological Heredity ◽  
Fatigue Defect

The influence of technological heredity on the interaction of the wheel and rail is considered. The state of the surface of the samples for the presence of contactfatigue defects is estimated. A relationship is established between the maximum height of waviness on the surface of the roller and the rate of damage to its surface. The dependence of the number of loading cycles of the rollers on the height of the waviness and the distribution of the run of the wheels of increased hardness between the turnings are constructed, which is consistent with experimental data. Keywords wheel, rails, contact-fatigue processes, technological heredity, wear, fatigue defect, wheel of increased hardness. [email protected]

IV.—The Carrara, Massa, and Versilia Marble District

1915 ◽  
Vol 2 (12) ◽  
pp. 554-565
Author(s):  
C. S. Du Riche Preller
Keyword(s):  
Sea Level ◽  
Coarse Grained ◽  
Maximum Height ◽  
The South ◽  
The North ◽  
The Mediterranean ◽  
Apuan Alps ◽  
Marble Industry

The range of the Apuan Alps, commonly called the Carrara Mountains, is an offshoot of the Apennines, trending N.N.W. to S.S.E., parallel to the Mediterranean littoral, from which it rises within a distance of barely four miles to a maximum height of 6,000 feet above sea-level. Exclusive of the outer belt of the more recent strata, the Triassic formation, within which the saccharoidal marble beds are situated, covers about 25 by 13 kilometres or about 130 square miles, of which the marble zone proper represents 64 square miles or about half. The range is bounded on the north by the Aullela valley in the Lunigiana district; on the east by the Serchio valley in the Garfagnana district; and on the south by the Serchio valley in the Province of Lucca. The marble district, whose western part faces the Mediterranean, comprises the three divisions of Carrara, Massa, and the Versilia in the corresponding parallel valleys of the Carrione, Frigido, and Serravezza Rivers. The Versilia division, which forms part of the Province of Lucca, is composed of the Seravezza, Stazzema, and Arni subdivisions, of which the last-named lies on the eastern watershed of the Apuan range. The Versilia division also includes Pietrasanta, Camajore, Massarosa, and the wellknown watering-place of Viareggio, near the last-named of which are situated extensive subaqueous deposits of a peculiarly coarse-grained, sharp macigno sand. These deposits, formed as a delta in a lacustrine expanse by the River Serchio, constitute an important and indispensable adjunct of the marble industry as grinding material for the numerous marble saw-mills in the three parallel valleys already referred to.

Sign in / Sign up

Export Citation Format

Share Document