scholarly journals Rheological Properties of Argillaceous Intercalation under the Combination of Static and Intermittent Dynamic Shear Loads

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xin Zhang ◽  
Qian Dong ◽  
Xiangping Zhang ◽  
Ming Lang ◽  
Suzhi Zhao ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Rock Slope ◽  
Soil Samples ◽  
Dynamic Loads ◽  
Shearing Stress ◽  
Dynamic Shear ◽  
Shear Loads ◽  
Dynamic Shearing ◽  
Static Shear

The construction and long-term operation stage of the rock slope with argillaceous interlayer will be subjected to intermittent dynamic loads, such as blasting and earthquake. For the argillaceous interlayer in the rock slope, its rheological properties are not only related to the initial stress state caused by the gravity of the overlying rock mass but also affected by intermittent dynamic loads. In order to investigate the rheological properties of argillaceous intercalation under the combination of static and intermittent dynamic shear loads, the rheological tests of argillic intercalated soil samples under static shear, static and cyclic dynamic shear, and static and intermittent dynamic shear were carried out, and the rheological deformation characteristics of soil samples under different shear conditions were analyzed. The results show that when the soil specimens in the static shear rheological process are disturbed by intermittent dynamic shearing load, the intermittent dynamic disturbances might have no remarkable influence on the rheological deformation of the specimens if the initial static shearing stress and intermittent dynamic shearing stress were comparatively low. However, low-intensity intermittent dynamic disturbances might accelerate the rheological deformation process of the specimens remarkably if the initial static shearing stress state was close to their shearing strength. There was a stress threshold when the soil specimens failed under the static and cycling dynamic shear and static and intermittent dynamic shear, which is determined by the sum of static shear stress and dynamic shear stress peak. For rock slopes controlled by rheological weak structural planes and influenced by long-term blasting vibrations, the transient and long-term dynamic stability should be comprehensively analyzed.

scholarly journals Effect of Photoinitiator on Precursory Stability and Curing Depth of Thiol-Ene Clickable Gelatin

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1877
Author(s):  
Kai-Hung Yang ◽  
Gabriella Lindberg ◽  
Bram Soliman ◽  
Khoon Lim ◽  
Tim Woodfield ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Visible Light ◽  
Rheological Properties ◽  
Swelling Ratio ◽  
Sodium Persulfate ◽  
Photo Polymerization ◽  
Gelation Kinetics ◽  
The Stability ◽  
Over Time

Recent advances highlight the potential of photopolymerizable allylated gelatin (GelAGE) as a versatile hydrogel with highly tailorable properties. It is, however, unknown how different photoinitiating system affects the stability, gelation kinetics and curing depth of GelAGE. In this study, sol fraction, mass swelling ratio, mechanical properties, rheological properties, and curing depth were evaluated as a function of time with three photo-initiating systems: Irgacure 2959 (Ig2959; 320–500 nm), lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP; 320–500 nm), and ruthenium/sodium persulfate (Ru/SPS; 400–500 nm). Results demonstrated that GelAGE precursory solutions mixed with either Ig2959 or LAP remained stable over time while the Ru/SPS system enabled the onset of controllable redox polymerization without irradiation during pre-incubation. Photo-polymerization using the Ru/SPS system was significantly faster (<5 s) compared to both Ig2959 (70 s) and LAP (50 s). Plus, The Ru/SPS system was capable of polymerizing a thick construct (8.88 ± 0.94 mm), while Ig2959 (1.62 ± 0.49 mm) initiated hydrogels displayed poor penetration depth with LAP (7.38 ± 2.13 mm) in between. These results thus support the use of the visible light based Ru/SPS photo-initiator for constructs requiring rapid gelation and a good curing depth while Ig2959 or LAP can be applied for photo-polymerization of GelAGE materials requiring long-term incubation prior to application if UV is not a concern.

Hydromechanical modeling of a large moving rock slope inferred from slope levelling coupled to spring long-term hydrochemical monitoring: example of the La Clapière landslide (Southern Alps, France)

2004 ◽  
Vol 291 (1-2) ◽  
pp. 67-90 ◽  
Author(s):  
F Cappa ◽  
Y Guglielmi ◽  
V.M Soukatchoff ◽  
J Mudry ◽  
C Bertrand ◽  
...  
Keyword(s):  
Rock Slope ◽  
Southern Alps ◽  
Hydrochemical Monitoring

Use of local crumb rubber as modifier, to improve the rutting resistance of bitumen

2021 ◽  
Author(s):  
Muhammad Saad Waheed ◽  
Muhammad Jamal ◽  
Manzoor Elahi
Keyword(s):  
Rheological Properties ◽  
Crumb Rubber ◽  
Critical Component ◽  
Dynamic Shear ◽  
Dynamic Shear Rheometer ◽  
Rutting Resistance

Abstract Bitumen is a critical component in asphaltic pavements and is often the cause of many road failures. The commercial modifiers that are being used to enhance the properties of bitumen are quite expensive; therefore, this article is dedicated to explore the potential of local crumb rubber as bitumen modifier. Two grades of bitumen pen grade (60/70 and 80/100) were modified with local crumb rubber. Rheological properties of modified and unmodified bitumen were evaluated using Dynamic Shear Rheometer. The results indicated an increase in the rutting resistance of bitumen. This indicates that Local crumb rubber can be used to enhance the properties of bitumen.

A Laboratory Study of Rheological Properties of Soft Mud Using a Dynamic Shear-controlled Oscillatory Viscometer

2018 ◽  
Vol 85 ◽  
pp. 1226-1230 ◽  
Author(s):  
Sihang Nie ◽  
Qin Jiang ◽  
Lizhu Wang ◽  
Jun Zhang ◽  
Peng Liu
Keyword(s):  
Rheological Properties ◽  
Laboratory Study ◽  
Dynamic Shear

scholarly journals Influence of long-term mineral fertilization on metal contents and properties of soil samples taken from different locations in Hesse, Germany

SOIL ◽  
2015 ◽  
Vol 1 (1) ◽  
pp. 23-33 ◽  
Author(s):  
S. Czarnecki ◽  
R.-A. Düring
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Agricultural Soils ◽  
Mineral Fertilizer ◽  
Fertilizer Application ◽  
Exchange Capacity ◽  
Soil Samples ◽  
Residual Effects ◽  
Metal Contents

Abstract. Essential and non-essential metals occur in soils as a result of weathering, industrial processes, fertilization, and atmospheric deposition. Badly adapted cultivation of agricultural soils (declining pH value, application of unsuitable fertilizers) can enhance the mobility of metals and thereby increase their concentrations in agricultural products. As the enrichment of metals in soils occurs over long time periods, monitoring of the long-term impact of fertilization is necessary to assess metal accumulation in agricultural soils. The main objective of this study was to test the effects of different mineral fertilizer variations on soil properties (pH, Corg, and cation exchange capacity (CEC)) and pseudo-total and mobile metal contents of soils after 14 years of fertilizer application and to determine residual effects of the fertilization 8 years after cessation of fertilizer treatment. Soil samples were taken from a field experiment which was carried out at four different locations (210, 260, 360, and 620 m above sea level) in Hesse, Germany. During the study, a significant decrease in soil pH and an evident increase in soil carbon content and cation exchange capacity with fertilization were determined. The CEC of the soils was closely related to their organic C contents. Moreover, pseudo- and mobile metal (Cd, Cu, Mn, Pb, Zn) contents in the soils increased due to application of 14 years of mineral fertilizer treatments (N, P, NP, and NPK) when compared to control plots. Eight years after termination of the fertilization in the soil samples taken from soil profiles of the fertilized plots (NPK) for monitoring the residual effects of the fertilizer application, a decrease of 82.6, 54.2, 48.5, 74.4, and 56.9% in pseudo-total Cd, Cu, Mn, Pb, and Zn contents, respectively, was determined.

Steady and dynamic shear rheological properties of açai pulp (Euterpe oleraceae Mart.)

2009 ◽  
Vol 92 (4) ◽  
pp. 425-431 ◽  
Author(s):  
R.V. Tonon ◽  
D. Alexandre ◽  
M.D. Hubinger ◽  
R.L. Cunha
Keyword(s):  
Rheological Properties ◽  
Dynamic Shear

scholarly journals ANALISIS GAYA GEMPA PADA BANGUNAN RUMAH TINGGAL DI WILAYAH GEMPA TINGGI

2018 ◽  
Vol 7 (2) ◽  
pp. 57-64
Author(s):  
Alfian Wiranata Zebua
Keyword(s):  
Structural Analysis ◽  
Shear Force ◽  
Structure Model ◽  
Dynamic Shear ◽  
Earthquake Loads ◽  
Story Drift ◽  
Loads Analysis ◽  
Support Reactions ◽  
Static Shear

Abstract : Four stories building was used as structure model. Static earthquake loads distribution were determined according to SNI 1726:2012. The effect of dynamic earthquake loads also considered. The result of structural analysis determined using ETABS. It were static shear force 1.082,64 KN and dynamic shear force, Fx = 1.057 KN and Fy = 983,5 KN. Colomn and beam forces were also determined. Support reactions and joint displacements were determined through structural analysis. Mass modal participation has been reached over 90% at mode 5. Story drift was still smaller than the allowable story drift.Keywords : earthquake loads analysis, residential building.Abstrak:Model struktur yang dianalisis yaitu gedung beraturan lantai 4 untuk rumah tinggal. Distribusi beban gempa statik diperoleh sesuai dengan SNI 1726:2012. Pengaruh beban gempa dinamik juga diperhitungkan. Hasil analisis struktur diperoleh antara lain besaran gaya geser statik 1.082,64 KN dan gaya geser dinamik, Fx = 1.057 KN dan Fy = 983,5 KN. Besaran gaya elemen kolom dan balok juga diperoleh. Reaksi tumpuan serta perpindahan titik buhul dapat diketahui dari hasil analisis yang dilakukan. Pada mode 5, partisipasi massa model yang dianalisis sudah mencapai 90%.Simpangan antar lantai yang terjadi pada model struktur tidak melebihi simpangan yang diijinkan.Kata kunci : analisis gaya gempa, bangunan rumah tinggal.

scholarly journals Long-term Effects of Mixed Planting on Arbuscular Mycorrhizal Fungal Communities in the Roots and Soils of Juglans mandshurica Plantations

2020 ◽  
Author(s):  
Li Ji ◽  
Yan Zhang ◽  
Yuchun Yang ◽  
Lixue Yang ◽  
Na Yang ◽  
...  
Keyword(s):  
Fungal Community ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Soil Samples ◽  
Fungal Communities ◽  
Juglans Mandshurica ◽  
Mixed Plantations ◽  
Mixed Plantation ◽  
Unique Otus

Abstract Background: Establishing mixed plantations is an effective way to improve soil fertility and increase forest productivity. Arbuscular mycorrhizal (AM) fungi are obligate symbiotic fungi that can promote mineral nutrient absorption and regulate intraspecific and interspecific competition in plants. However, the effects of mixed plantations on the community structure and abundance of AM fungi are still unclear. Illumina MiSeq sequencing was used to investigate the AM fungal community in the roots and soils of pure and mixed plantations (Juglans mandshurica × Larix gmelinii). The objective of this study is to compare the differential responses of the root and rhizosphere soil AM fungal communities of Juglans mandshurica to long-term mixed plantation management.Results: Glomus and Paraglomus were the dominant genera in the root samples, accounting for more than 80% of the sequences. Compared with that in the pure plantation, the relative abundance of Glomus was higher in the mixed plantation. Glomus, Diversispora and Paraglomus accounted for more than 85% of the sequences in the soil samples. The relative abundances of Diversispora and an unidentified genus of Glomeromycetes were higher and lower in the pure plantation, respectively. The Root_P samples (the roots in the pure plantation) had the highest number of unique OTUs (operational taxonomic units), which belonged mainly to an unidentified genus of Glomeromycetes, Paraglomus, Glomus and Acaulospora. The number of unique OTUs detected in the soil was lower than that in the roots. In both the root and soil samples, the forest type did not have a significant effect on AM fungal diversity, but the Sobs value and the Shannon, Chao1 and Ace indices of AM fungi in the roots were significantly higher than those in the soil.Conclusions: Mixed forest management had little effect on the AM fungal community of Juglans mandshurica roots and significantly changed the community composition of the soil AM fungi, but not the diversity.

scholarly journals Observation of the rock slope thermal regime, coupled with crack meter stability monitoring

2021 ◽  
Author(s):  
Ondřej Racek ◽  
Jan Blahůt ◽  
Filip Hartvich
Keyword(s):  
Rock Mass ◽  
Monitoring System ◽  
Rock Slope ◽  
Global Radiation ◽  
Environmental Parameters ◽  
Radiation Balance ◽  
Rock Types ◽  
Novel Approach ◽  
First Results

Abstract. This article describes an innovative, complex and affordable monitoring system designed for joint observation of environmental parameters, rock block dilatations and temperature distribution inside the rock mass with a newly designed 3-meter borehole temperature sensor. Global radiation balance data are provided by pyranometers. The system introduces a novel approach for internal rock mass temperature measurement, which is crucial for the assessment of the changes in the stress field inside the rock slope influencing its stability. The innovative approach uses an almost identical monitoring system at different sites allowing easy setup, modularity and comparison of results. The components of the monitoring system are cheap, off-the-shelf and easy to replace. Using this newly designed system, we are currently monitoring three different sites, where the potential rock fall may endanger society assets below. The first results show differences between instrumented sites, although data time-series are relatively short. Temperature run inside the rock mass differs for each site significantly. This is very likely caused by different aspects of the rock slopes and different rock types. By further monitoring and data processing, using advanced modelling approaches, we expect to explain the differences among the sites, the influence of rock type, aspect and environmental variables on the long-term slope stability.

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