Pore distribution and classification of loess

The micro-pore characteristics in undisturbed loess have a profound influence on the permeability characteristics. Based on the results of permeability test, it is proved that the permeability coefficient of soil samples with the same porosity ratio is different and the internal characteristics are diversified. The internal pores of undisturbed loess were studied by scanning electron microscopy (SEM). The results show that there are obvious differences in the internal microstructure of the original loess with the same porosity ratio. There are root holes in undisturbed loess, the number and size of which directly affect the value of permeability coefficient. With the increase of pore diameter, the pore size distribution changes gradually, and the influence of small pores is gradually weakened, while the influence of large pores is more obvious. Therefore, only the pore ratio parameter used in engineering can not completely describe the pore characteristics of soil, it is necessary to introduce other microscopic parameters to describe.

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Study on Crack Development and Micro-Pore Mechanism of Expansive Soil Improved by Coal Gangue under Drying–Wetting Cycles

Materials ◽

10.3390/ma14216546 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6546

Author(s):

Hongxing Zhu ◽

Yan Zhang ◽

Zhuhan Li ◽

Xiaoyu Xue

Keyword(s):

Soil Sample ◽

Pore Volume ◽

Pore Diameter ◽

Expansive Soil ◽

Soil Samples ◽

Coal Gangue ◽

Pore Density ◽

Pore Characteristics ◽

Average Pore ◽

Road Engineering

Expansive soil is prone to cracks under a drying–wetting cycle environment, which brings many disasters to road engineering. The main purpose of this study is use coal gangue powder to improve expansive soil, in order to reduce its cracks and further explore its micro-pore mechanism. The drying–wetting cycles test is carried out on the soil sample, and the crack parameters of the soil sample are obtained by Matlab and Image J software. The roughness and micro-pore characteristics of the soil samples are revealed by means of the Laser confocal 3D microscope and Mercury intrusion meter. The results show that coal gangue powder reduces the crack area ratio of expansive soil by 48.9%, and the crack initiation time is delayed by at least 60 min. Coal gangue powder can increase the internal roughness of expansive soil. The greater the roughness of the soil, the less cracks in the soil. After six drying–wetting cycles, the porosity and average pore diameter of the improved and expanded soil are reduced by 37% and 30%, respectively, as compared to the plain expansive soil. By analyzing the cumulative pore volume and cumulative pore density parameters of soil samples, it is found that the macro-cracks are caused by the continuous connection and fusion of micro-voids in soil. Coal gangue powder can significantly reduce the proportion of micro-voids, cumulative pore volume, and cumulative pore density in expansive soil, so as to reduce the macro-cracks.

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Experimental Study on the Saturated Compacted Loess Permeability under K0 Consolidation

Advances in Civil Engineering ◽

10.1155/2020/1426485 ◽

2020 ◽

Vol 2020 ◽

pp. 1-16

Author(s):

Yan-zhou Hao ◽

Tie-hang Wang ◽

Xin Jin ◽

Lei Cheng ◽

Jiang-le Li

Keyword(s):

Permeability Coefficient ◽

Vertical Direction ◽

Confining Pressure ◽

Field Analysis ◽

Dry Density ◽

Anisotropy Ratio ◽

Permeability Test ◽

Permeability Characteristics ◽

Permeability Anisotropy ◽

Compacted Loess

This paper investigates the permeability characteristics of compacted loess by focusing on the anisotropy parallel and perpendicular to the compaction. Three tests are conducted on compacted loess: triaxial permeability test under confining pressure consolidation, triaxial permeability test under K0 consolidation, and SEM test. Samples are maintained and tested at different dry densities under saturated conditions. The test results show that the saturated permeability coefficient of compacted loess is exponentially related to the initial dry density under both confining pressure consolidation and K0 consolidation. The fitting equation can estimate the saturated permeability coefficient of compacted loess at different depths. The horizontal saturated permeability coefficient of compacted loess is larger than that in the vertical direction, showing obvious anisotropy. The saturated permeability anisotropy ratio is linearly related to the initial dry density. Comparing and analysing the saturated permeability coefficient, the saturated permeability coefficient of compacted loess under the K0 consolidation condition is smaller than that under the confining pressure consolidation condition. Under the condition of K0 consolidation, the connectivity of vertical and horizontal pores of compacted loess is weakened, the tortuosity is strengthened, and the void ratio is decreased. K0 consolidation makes the flake-, plate-, and needle-like particles in compacted loess rotate continuously parallel to the compaction surface, which enhances the orientation of particles and leads to the saturated permeability anisotropy increase. The research results provide the basis for water field analysis in loess filling engineering.

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Permeability Characteristics and Classification of Coal Seams in Nigeria

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.62-64.357 ◽

2009 ◽

Vol 62-64 ◽

pp. 357-367

Author(s):

B.M. Olaleye ◽

O.O. Onyemaobi ◽

J.M. Akande

Keyword(s):

Coal Seam ◽

Triaxial Compression ◽

Pressure Gauge ◽

Water Tank ◽

Permeability Test ◽

Coal Seams ◽

Permeability Characteristics ◽

Water Infusion ◽

The Difference

In this work, the permeability characteristics of Nigerian coal seams were determined and these properties were used to investigation the applicability of water infusion in the coal seams to solve coal-mining problems. The experimental work was conducted with Triaxial Compression Machine adapted for the permeability test comprising of Hoek cell, a self- developed water piston, pressure gauge and an overhead water tank. The results of the investigation showed that the permeability measurements of the coals were consistent at the different sites and locations of the coalmines. It also revealed that the difference in coal seam permeability was relatively small in Nigeria.

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K-MEANS CLUSTERING ALGORITHM BASED CLASSIFICATION OF SOIL FERTILITY IN NORTH WEST NIGERIA

FUDMA Journal of Sciences ◽

10.33003/fjs-2020-0402-363 ◽

2020 ◽

Vol 4 (2) ◽

pp. 780-787

Author(s):

Ibrahim Hassan Hayatu ◽

Abdullahi Mohammed ◽

Barroon Ahmad Isma’eel ◽

Sahabi Yusuf Ali

Keyword(s):

Soil Fertility ◽

Crop Yield ◽

Clustering Algorithm ◽

Soil Samples ◽

North West ◽

R Programming ◽

Available Information ◽

Northwest Region ◽

The Relationship

Soil fertility determines a plant's development process that guarantees food sufficiency and the security of lives and properties through bumper harvests. The fertility of soil varies according to regions, thereby determining the type of crops to be planted. However, there is no repository or any source of information about the fertility of the soil in any region in Nigeria especially the Northwest of the country. The only available information is soil samples with their attributes which gives little or no information to the average farmer. This has affected crop yield in all the regions, more particularly the Northwest region, thus resulting in lower food production. Therefore, this study is aimed at classifying soil data based on their fertility in the Northwest region of Nigeria using R programming. Data were obtained from the department of soil science from Ahmadu Bello University, Zaria. The data contain 400 soil samples containing 13 attributes. The relationship between soil attributes was observed based on the data. K-means clustering algorithm was employed in analyzing soil fertility clusters. Four clusters were identified with cluster 1 having the highest fertility, followed by 2 and the fertility decreases with an increasing number of clusters. The identification of the most fertile clusters will guide farmers on where best to concentrate on when planting their crops in order to improve productivity and crop yield.

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Study on the influence on the formation of highly ordered porous anodic aluminia membrane

10.26434/chemrxiv.5743170.v1 ◽

2017 ◽

Author(s):

O Pong-Sik ◽

Ryang Se-Hun ◽

Sin Gum-Chol ◽

Hwang Guk-Nam ◽

yongson hong

Keyword(s):

Pore Diameter ◽

Electrolyte Concentration ◽

Aao Template ◽

Alumina Template ◽

Wide Range ◽

Electrochemical Mechanism ◽

Porous Anodic Alumina Template ◽

Ordered Porous ◽

Anodic Alumina Template ◽

Scanning Electron

We have studied porous anodic alumina template through the second anodic oxidation of preparation. Observing the morphology of nanoscale AAO template using scanning electron microscope (SEM), the results indicate that the pores are orderly paralleled arranged with uniform pore diameter, perpendicular to the template surface. A detailed study of the influence of different oxidation conditions, such as different type of electrolyte, concentration, voltage and temperature on the template of alumina and its electrochemical mechanism were performed. By changing the oxidation voltage, electrolyte type, concentration, pore diameter and template thickness can be altered in a wide range such that we can obtain the desired aspect ratio. <br>

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Pollen morphology of Iranian Dracocephalum L. (Lamiaceae) and its taxonomic significance

Bangladesh Journal of Plant Taxonomy ◽

10.3329/bjpt.v22i2.26071 ◽

2015 ◽

Vol 22 (2) ◽

pp. 99-110 ◽

Cited By ~ 3

Author(s):

Maryam Naderifar ◽

Ali Sonboli ◽

Abbas Gholipour

Keyword(s):

Electron Microscopy ◽

Pollen Morphology ◽

Pollen Grains ◽

Polar View ◽

Taxonomic Significance ◽

Infrageneric Classification ◽

Exine Ornamentation ◽

Plant Taxon ◽

Scanning Electron

Pollen morphology of 11 Iranian Dracocephalum L. species was investigated using light and scanning electron microscopy to evaluate their taxonomic significance for the infrageneric classification of the genus. Pollen grains of all examined taxa were isopolar, hexacolpate, circular in polar view and spheroidal to prolate in equatorial view (P/E = 1.0?2.0). The smallest pollen grains were observed in D. aucheri (P = 29.7 ?m, E = 22.6 ?m), while the largest pollen was found in D. lindbergii (P = 45.1 ?m, E = 33.7 ?m). The highest and lowest apocolpium index (AI) were measured in D. aucheri (AI = 0.27) and D. surmandinum (AI = 0.08), respectively. Colpus membrane was egranulate in all examined species except for D. multicaule and D. ghahremanii. The main exine ornamentation type was characterized as bireticulate including five different subtypes. The results revealed that the exine ornamentation is a diagnostic character useful for the classification of Dracocephalum.Bangladesh J. Plant Taxon. 22(2): 99-110, 2015 (December)

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Bacteriophages LIMElight and LIMEzero of Pantoea agglomerans, Belonging to the “phiKMV-Like Viruses”

Applied and Environmental Microbiology ◽

10.1128/aem.00128-11 ◽

2011 ◽

Vol 77 (10) ◽

pp. 3443-3450 ◽

Cited By ~ 35

Author(s):

Evelien M. Adriaenssens ◽

Pieter-Jan Ceyssens ◽

Vincent Dunon ◽

Hans-Wolfgang Ackermann ◽

Johan Van Vaerenbergh ◽

...

Keyword(s):

Soil Samples ◽

Pantoea Agglomerans ◽

Open Reading Frames ◽

Human Pathogen ◽

Content Type ◽

Host Diversity ◽

Double Stranded Dna ◽

Opportunistic Human Pathogen ◽

Reading Frames

ABSTRACTPantoea agglomeransis a common soil bacterium used in the biocontrol of fungi and bacteria but is also an opportunistic human pathogen. It has been described extensively in this context, but knowledge of bacteriophages infecting this species is limited. Bacteriophages LIMEzero and LIMElight ofP. agglomeransare lytic phages, isolated from soil samples, belonging to thePodoviridaeand are the firstPantoeaphages of this family to be described. The double-stranded DNA (dsDNA) genomes (43,032 bp and 44,546 bp, respectively) encode 57 and 55 open reading frames (ORFs). Based on the presence of an RNA polymerase in their genomes and their overall genome architecture, these phages should be classified in the subfamily of theAutographivirinae, within the genus of the “phiKMV-like viruses.” Phylogenetic analysis of all the sequenced members of theAutographivirinaesupports the classification of phages LIMElight and LIMEzero as members of the “phiKMV-like viruses” and corroborates the subdivision into the different genera. These data expand the knowledge ofPantoeaphages and illustrate the wide host diversity of phages within the “phiKMV-like viruses.”

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An analysis of Apollo lunar soil samples 12070,889, 12030,187, and 12070,891: Basaltic diversity at the Apollo 12 landing site and implications for classification of small-sized lunar samples

Meteoritics and Planetary Science ◽

10.1111/maps.12689 ◽

2016 ◽

Vol 51 (9) ◽

pp. 1654-1677 ◽

Cited By ~ 2

Author(s):

Louise Alexander ◽

Joshua F. Snape ◽

Katherine H. Joy ◽

Hilary Downes ◽

Ian A. Crawford

Keyword(s):

Landing Site ◽

Lunar Soil ◽

Soil Samples ◽

Lunar Samples

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Permeability of Concrete and Correlation with Microstructure Parameters Determined by 1H NMR

Advances in Materials Science and Engineering ◽

10.1155/2020/4969680 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11

Author(s):

Yurong Zhang ◽

Shengxuan Xu ◽

Zhaofeng Fang ◽

Junzhi Zhang ◽

Chaojun Mao

Keyword(s):

Water Permeability ◽

Permeability Coefficient ◽

Pore Diameter ◽

Gas Permeability ◽

Steady State Flow ◽

Test Device ◽

Water Permeability Coefficient ◽

Microstructure Parameters ◽

The Relationship ◽

Better Than

Water and gas permeability coefficients of concrete with different water-binder (w/b) ratios and admixtures were measured by a self-designed test device based on the steady-state flow method for liquid and the method of differential pressure in stability for gas, respectively. In addition, the micropore structure of concrete was determined by 1H nuclear magnetic resonance (NMR). Results indicated that there are good correlations between water and gas permeability of concrete with different w/b ratios, with correlation coefficient greater than 0.90. Better correlations between water permeability and segmental contributive porosity ranged from 10 to 100 nm and 100 to 1000 nm can be identified, but the gas permeability is more relevant to the segmental contributive porosity ranging from 100 to 1000 nm. Moreover, the correlation between water permeability and contributive porosity for each pore diameter is always better than that of gas permeability. The influence of admixtures on the relationship between permeability and pore size distribution of concrete is significant. Moreover, water permeability coefficient is one or two orders of magnitude lower than the gas permeability coefficient.

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