Strain Energy and Behaviour of Overconsolidated Soils

1967 ◽  
Vol 4 (3) ◽  
pp. 326-333 ◽  
Author(s):  
Elmer W Brooker

Bjerrum recently presented a strain energy hypothesis which explains qualitatively the behaviour of overconsolidated clays and the phenomena of long-term slope failures in these soils. Quantitative evidence, gathered from a series of large-scale consolidation tests, is presented here which supports the strain energy hypothesis. The coefficient of earth pressure at rest was found to be a function of strain energy at a given value of OCR. It is also shown that the degree of disintegration of overconsolidated soils during a slaking test is related to strain energy. It is inferred from the results that mineralogy and the capacity of a soil to adsorb strain energy are related. The evidence suggests that certain physico-chemical properties may be quantitatively related to mechanical properties through the concept of strain energy.

2013 ◽  
Vol 688 ◽  
pp. 123-129 ◽  
Author(s):  
Grigorii Vozniuk ◽  
Еlena Kаvalerova ◽  
Pavel Vasiljevich Krivenko ◽  
Оleg Petropavlovsky

This paper covers the results of study of physico-chemical and mechanical properties of the adhesives based on geocements which have a number of advantageous properties, among them: high compressive and bond strength in the conditions of long-term exposure of various factors, excellent durability, etc. These adhesives are environmentally and user-friendly and safety, their cost is compatible to the known-in-the-art analogs. The results of study suggested to draw a conclusion that they could be successfully used for rehabilitation and restoration of the building materials such as concrete, ceramics, natural stone.


1987 ◽  
Vol 35 (2) ◽  
pp. 135 ◽  
Author(s):  
RB Hacker

Species responses to grazing and environmental factors were studied in an arid halophytic shrubland community in Western Australia. The grazing responses of major shrub species were defined by using reciprocal averaging ordination of botanical data, interpreted in conjunction with a similar ordination of soil chemical properties and measures of soil erosion derived from large-scale aerial photographs. An apparent small-scale interaction between grazing and soil salinity was also defined. Long-term grazing pressure is apparently reduced on localised areas of high salinity. Environmental factors affecting species distribution are complex and appear to include soil salinity, soil cationic balance, geomorphological variation and the influence of cryptogamic crusts on seedling establishment.


Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2215 ◽  
Author(s):  
Ruiwen Li ◽  
Chuan Mo ◽  
Yichuan Liao

The physico-chemical properties of the Uranium intermetallic compound are of technological importance for improvement of the safety and compatibility of nuclear engineering systems. Diffusion couple samples with U and Cu were assembled and U-Cu intermetallic compounds were fabricated at interface by hot pressure diffusion method at a treatment temperature of 350 °C to 650 °C and at a pressure of 168 MPa in a vacuum furnace. The microstructure and element distribution of the compound phase have been studied by means of SEM, EDS, and XRD. The result showed that a new phase was developed to a thickness of approximately 10 μm with a ration of U:Cu with 1:5. Mechanical properties such as elastic moduli and hardness of the compound have been studied by means of nanoindentation. The nanoindentation testing on sample indicated that hardness of Uranium intermetallic compound are higher than that of metal U and Cu. Uranium intermetallic compound and U have a Young’s moduli with 121 GPa, 160 GPa respectively. The elastic/plastic responses of U-Cu intermetallic compound and U under nanoindentation tests were also discussed in detail.


Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Shin Min Kang ◽  
Muhammad Yousaf ◽  
Manzoor Ahmad Zahid ◽  
Muhammad Younas ◽  
Waqas Nazeer

Abstract Dendrimers are profoundly extended natural macromolecules with successive layers of branch units encompassing a central core. Topological indicess are numbers related with graph of a compound to allow quantitative structureactivity/property/lethality connections. These topological indices relate certain physico-chemical properties like stability, boiling point, strain energy and so forth of a compound. In this report, there have been computed redefined first, second and third Zagreb indices of Nanostar dendrimers. The authors also analyzed some Zagreb polynomials of understudy dendrimers.


2008 ◽  
Vol 4 (S254) ◽  
pp. 133-138
Author(s):  
G. M. De Silva ◽  
K. C. Freeman ◽  
J. Bland-Hawthorn

AbstractThe long term goal of large-scale chemical tagging is to use stellar elemental abundances as a tracer of dispersed substructures of the Galactic disk. The identification of such lost stellar aggregates and exploring their chemical properties will be key in understanding the formation and evolution of the disk. Present day stellar structures such as open clusters and moving groups are the ideal testing grounds for the viability of chemical tagging, as they are believed to be the remnants of the original larger star-forming aggregates. We examine recent high resolution abundance studies of open clusters to explore the various abundance trends and reassess the prospects of large-scale chemical tagging.


2017 ◽  
Vol 284 (1858) ◽  
pp. 20170722 ◽  
Author(s):  
Bjarte Hannisdal ◽  
Kristian Agasøster Haaga ◽  
Trond Reitan ◽  
David Diego ◽  
Lee Hsiang Liow

Common species shape the world around us, and changes in their commonness signify large-scale shifts in ecosystem structure and function. However, our understanding of long-term ecosystem response to environmental forcing in the deep past is centred on species richness, neglecting the disproportional impact of common species. Here, we use common and widespread species of planktonic foraminifera in deep-sea sediments to track changes in observed global occupancy (proportion of sampled sites at which a species is present and observed) through the turbulent climatic history of the last 65 Myr. Our approach is sensitive to relative changes in global abundance of the species set and robust to factors that bias richness estimators. Using three independent methods for detecting causality, we show that the observed global occupancy of planktonic foraminifera has been dynamically coupled to past oceanographic changes captured in deep-ocean temperature reconstructions. The causal inference does not imply a direct mechanism, but is consistent with an indirect, time-delayed causal linkage. Given the strong quantitative evidence that a dynamical coupling exists, we hypothesize that mixotrophy (symbiont hosting) may be an ecological factor linking the global abundance of planktonic foraminifera to long-term climate changes via the relative extent of oligotrophic oceans.


2018 ◽  
Author(s):  
Jayalakshmi Mitnala

Sorghum and wheat are the premier food grain crops of the peninsular central India and in particular of Maharashtra. There has been a phenomenal increase in its production after mid sixties with the introduction of high yielding varieties. Increase in production was achieved through increase in area as well as productivity. Inputs like improved seeds, irrigation, fertilizers etc. has given a boost to productivity. Continuous addition of chemical fertilizers poses problems like toxicity due to high amounts of salts as residues of fertilizer and deterioration of the physico-chemical properties. Organic manure ameliorates this problem as organic matter helps in increasing adsorptive power of soil for cations and anions particularly phosphate and nitrate. Long term manuring and fertilizer experiments conducted in India showed declining trend in productivity even with the application of NPK fertilizers under modern intensive farming. Neither organic source alone nor inorganic fertilizers can achieve sustainability in crop production under intensive agriculture, where nutrient turnover in soil-plant system is much higher. However, their combined use appeared promising in enhanced crop productivity besides improving soil fertility.


Author(s):  
Amol M. Jadhav ◽  
Pravin U. Singare

Ulhas River which is one of the most polluted rivers of Mumbai receives heavy pollution load from the nearby Dombivali industrial belt. Previous studies reported along the Dombivali industrial belt has indicated that the pollution level is so much alarming that it has created threat to nearby residential areas and also to the Ulhas River flowing in the outskirts of the Dombivali City. It is feared that the toxic chemicals present in the industrial waste might affect the sediment ecosystem of the river. Hence this has provoked us to carry the systematic and detailed study of physico chemical properties of the sediment samples collected along the Ulhas River. The study was done during the year 2012 and 2013, at the sites where the industrial discharge from Dombivli industrial belt Phase I and Phase II joins the Ulhas River. The study was performed to understand the physico chemical properties such as pH, alkalinity, chloride and phosphates. Results of the study reveal that there is an urgent requirement for systematic and regular monitoring of pollution level along the Ulhas River which will further help in improving the industrial waste treatment procedure adopted, along the Dombivli industrial belt. It is expected that such scientific studies will be useful to determine the extent of pollution control measures required in order to avoid long term irreparable damage to the Ulhas River ecosystem.


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