The effect of Elymus nutans sowing density on soil reinforcement and slope stabilization properties of vegetation–concrete structures

AbstractElymus nutans is an herbaceous plant that can be used to restore degraded alpine and subalpine ecosystems. Here, we evaluated how sowing density affects soil reinforcement and slope stabilization properties of vegetation–concrete structures. To investigate the optimal sowing density of E. nutans in vegetation–concrete applications for slope protection, six experimental treatments were established with different plant densities: control, I (1100 seeds/m2), II (2200 seeds/m2), III (3300 seeds/m2), IV (4400 seeds/m2), and V (5500 seeds/m2). Several parameters of plant growth in addition to soil reinforcement and slope stabilization properties were measured in each treatment, as well as the associations among parameters. As density increased, aboveground biomass continually increased, and plant heights, root surface areas, root lengths, and underground biomass all first increased and then decreased. In contrast, tiller numbers and the average root diameter gradually decreased with increasing density. Increased density also resulted in increased maximum water interception levels by aboveground stems and leaves. The maximum water interception by the aboveground stems and leaves was 41.75% greater in the highest density treatment (V) compared to the lowest density treatment (I). However, the enhancement of erosion resistance and soil shear strength first increased and then decreased as density increased, with maximal values observed in the medium-high density treatment (IV). Sowing density was highly correlated with aboveground biomass, plant heights, tiller numbers, and the maximum level of water interception by stems and leaves. Thus, sowing density directly influenced soil reinforcement and slope stabilization properties of aboveground plant components. However, density was not significantly correlated with belowground biomass, root lengths, root surface areas, the enhancement of erosion resistance, and soil shear strengths. Therefore, sowing density indirectly influenced soil reinforcement and slope stabilization of belowground plant components. Following from these results, we suggest that the optimal sowing density of E. nutans is approximately 4400 plants/m2 in their application within vegetation–concrete structures used for slope protection.

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Investigation on the arc erosion behavior of new silver matrix composites: Part I. Reinforced by particles

Journal of Materials Research ◽

10.1557/jmr.2003.0111 ◽

2003 ◽

Vol 18 (4) ◽

pp. 804-816 ◽

Cited By ~ 9

Author(s):

Shou-Yi Chang ◽

Chia-Jung Hsu ◽

Cher-Hao Hsu ◽

Su-Jien Lin

Keyword(s):

Particle Size ◽

Erosion Resistance ◽

High Viscosity ◽

Matrix Composites ◽

Particle Content ◽

Arc Erosion ◽

Erosion Behavior ◽

Surface Areas ◽

Large Particles ◽

Silver Matrix

Static-gap, single-spark tests were used to investigate the arc erosion behavior of newly developed silicon carbide and alumina particle reinforced silver matrix composites (SiCp/Ag, Al2O3p/Ag). Craters and hills exist on the surfaces of eroded silver matrix composites, and their depths and sizes decrease as the particle content increases and the particle size decreases. Obvious melting, flow, severe splash of molten silver, and the segregation of particles are present on the surfaces of eroded composites containing low volume percents of large particles. Easier silver flow results in smooth surfaces and reduces the total surface areas of the eroded composites containing large particles. The flow and splash of silver decreased with increasing particle content and decreasing particle size, exhibiting a better erosion resistance to single-spark tests. The static-gap, single-spark erosion behavior of silver matrix composites is dominated by the flow and splash of molten composites. A high viscosity of the liquids provides the composites a good arc erosion resistance.

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Effect of Initial Surface Roughness on Water Erosion Resistance of Last Stage Blade Substrate of Steam Turbine

Volume 2B: Turbomachinery ◽

10.1115/gt2020-16262 ◽

2020 ◽

Author(s):

Fang Li ◽

Shunsen Wang ◽

Juan Di ◽

Zhenping Feng

Keyword(s):

Numerical Simulation ◽

Surface Roughness ◽

Steam Turbine ◽

Water Droplet ◽

Erosion Resistance ◽

Water Erosion ◽

Experimental Results ◽

Initial Surface ◽

Maximum Water ◽

Last Stage

Abstract In order to study the effect of initial surface roughness on water droplet erosion resistance of last stage blade substrate of steam turbine, eight 17-4PH samples were grounded and velvet polished by different mesh metallographic sandpaper to establish sample with different initial surface roughness. The water droplet erosion experiments were carried out in the highspeed jet water erosion experiment system, and the mass and micro-morphology of each sample were measured by using precision electronic balance and ultra-depth of field microscope respectively at each experimental stage, and the measurement of water erosion trace width and maximum water erosion depth were also completed at the same time. On the basis of experiments, LS-DYNA was used for numerical simulation to verify the reliability of experimental results again. Results show that the smoother the initial surface of sample, then the smaller the mass loss, the stronger its water erosion resistance. On the contrary, the rougher the initial surface of sample, the more severe the surface irregularity, the more times the water droplets concentrated at the lowest point of pit when water droplets flow laterally after impact is completed, thus accelerating the formation of initial crack and lateral expansion, the poorer the water erosion resistance of sample. At same water erosion time, the smoother the sample surface, the later the complete erosion trace appear, the narrower the water erosion trace width. However, the maximum water erosion depth of sample is not affected by the initial surface roughness. The numerical simulation results are in good agreement with the experimental results.

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Root surface areas of maxillary permanent teeth in anterior normal overbite and anterior open bite assessed using cone-beam computed tomography

Imaging Science in Dentistry ◽

10.5624/isd.2017.47.4.241 ◽

2017 ◽

Vol 47 (4) ◽

pp. 241 ◽

Cited By ~ 1

Author(s):

Piyadanai Suteerapongpun ◽

Supassara Sirabanchongkran ◽

Tanapan Wattanachai ◽

Patiyut Sriwilas ◽

Dhirawat Jotikasthira

Keyword(s):

Computed Tomography ◽

Cone Beam Computed Tomography ◽

Root Surface ◽

Open Bite ◽

Cone Beam ◽

Permanent Teeth ◽

Anterior Open Bite ◽

Surface Areas

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Initiation of root growth stimulation by Azospirillum lipoferum CRT1 during maize seed germination

Canadian Journal of Microbiology ◽

10.1139/w99-023 ◽

1999 ◽

Vol 45 (4) ◽

pp. 339-342 ◽

Cited By ~ 24

Author(s):

Colette Jacoud ◽

Dominique Job ◽

Patrick Wadoux ◽

René Bally

Keyword(s):

Root Growth ◽

Growth Stimulation ◽

Root Surface ◽

Growth Surface ◽

Azospirillum Lipoferum ◽

Optimal Density ◽

Continuous Contact ◽

Surface Areas ◽

Maize Seeds ◽

Commercial Inoculant

Maize seeds were inoculated with a commercial inoculant containing 1.3 × 107 Azospirillum lipoferum CRT1 cells. After 24 or 48 h, bacteria were washed from the seed surface. Washed and unwashed seeds were then planted in pots containing perlite and grown for 28 days under greenhouse conditions. Whatever the density of Azospirillum at planting, the number of these bacteria at the end of the experiment was similar (1.9-8.0 × 107 bacteria·plant-1). However, comparison of root surface areas of the plants were different depending on the period of contact between seeds and the density of the inoculum. Twenty-four hours of contact was not sufficient to increase root growth surface areas. Contact for 48 h permitted us to obtain root surface areas comparable with those measured after a continuous contact. These results showed that in order to promote maize root surface areas, an optimal density of Azospirillum is not required during the whole cultural cycle. This optimal density is indispensable only up to the emergence of the radicle.Key words: Azospirillum, maize, inoculation, PGPR.

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Biochar amendment increases maize root surface areas and branching: a shovelomics study in Zambia

Plant and Soil ◽

10.1007/s11104-015-2533-2 ◽

2015 ◽

Vol 395 (1-2) ◽

pp. 45-55 ◽

Cited By ~ 69

Author(s):

Samuel Abiven ◽

Andreas Hund ◽

Vegard Martinsen ◽

Gerard Cornelissen

Keyword(s):

Root Surface ◽

Maize Root ◽

Surface Areas ◽

Biochar Amendment

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Studies on root surface areas of the extracted teeth with periodontal problems.

Nihon Shishubyo Gakkai Kaishi (Journal of the Japanese Society of Periodontology) ◽

10.2329/perio.29.579 ◽

1987 ◽

Vol 29 (2) ◽

pp. 579-585

Author(s):

Hidetada ISHIKAWA ◽

Naomi UCHIDA ◽

Harumi OONISHI ◽

Junko NAKAJIMA ◽

Atsushi FUJII ◽

...

Keyword(s):

Root Surface ◽

Surface Areas

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Effect of elevated Al and pH on the growth and root morphology of Al-tolerant and Al-sensitive wheat seedlings in an acid soil .

Spanish Journal of Soil Science ◽

10.3232/sjss.2014.v4.n1.04 ◽

2014 ◽

Vol 4 ◽

Author(s):

Md. Toufiq Iqbal

Keyword(s):

Soil Ph ◽

Root Morphology ◽

Acid Soil ◽

Root Surface ◽

Root Tip ◽

Al Tolerance ◽

Wheat Seedlings ◽

Surface Areas ◽

Organic Acid Exudation ◽

Extractable Al

Aluminium ion (Al3+) toxicity and hydrogen ion (H+) activity are the major constraints for plant growth in acid soil. This study was undertaken to determine the effect of pH and Al on the growth response and changes in root morphology of Al-tolerant (ET8) and Al-sensitive (ES8) wheat seedlings. Different levels of AlCl3 and CaCO3 were added to the soils to manipulate soil pH and extractable Al. The results showed that the bulk soil pH remained constant at pH 4.1 with further applications of AlCl3, and that the seedlings died at the 200 mg AlCl3/kg treatments. The ET8 seedlings responded better than the ES8 seedlings in both low and high Al and pH. The ET8 seedlings had higher root surface areas and root tip numbers than the ES8 seedlings in the Al treatment. In contrast, the ES8 had higher root diameters than the ET8 seedlings due to the elevated Al supply. Apoplast Al increased with the increase of soil available extractable Al, and declined with the decrease of soil extractable Al. The ET8 seedlings accumulated more Al in their apoplast than the ES8 seedlings. This study concluded that accumulation of Al in the apoplast is also involved in Al tolerance mechanism with the addition of organic acid exudation.

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