scholarly journals Laboratory testing on compacted, partially saturated silty and sandy soils

2017 ◽  
Vol 1 (2) ◽  
pp. 13-27
Author(s):  
G. E. Scarcella ◽  
◽  
I. Giusti ◽  
S. Giusti ◽  
D. Lo Presti ◽  
...  
Keyword(s):  
Laboratory Testing ◽  
Sandy Soils ◽  
Partially Saturated

Mechanical model for partially saturated sandy soils

2010 ◽  
pp. 763-769
Author(s):  
H Bian ◽  
T Nishimura ◽  
I Shahrour
Keyword(s):  
Mechanical Model ◽  
Sandy Soils ◽  
Partially Saturated

scholarly journals Enhancement of the thermal conductivity of sands via microbially-induced calcite precipitation

2020 ◽  
Vol 205 ◽  
pp. 09011
Author(s):  
Alejandro Martinez ◽  
Lin Huang ◽  
Michael G. Gomez
Keyword(s):  
Thermal Conductivity ◽  
Ground Improvement ◽  
Soil Column ◽  
Sandy Soils ◽  
Shear Stiffness ◽  
Degree Of Saturation ◽  
Engineering Properties ◽  
Calcite Precipitation ◽  
Microbially Induced Calcite Precipitation ◽  
Partially Saturated

Energy piles and ground source heat pump systems have been shown to provide sustainable alternatives for temperature regulation in buildings and other applications such as road de-icing. However, their efficiency can be undermined in partially-saturated and dry sandy soils due to the relatively low thermal conductivity (kt) of these materials. Microbially-Induced Calcite Precipitation (MICP) has been demonstrated to be an environmentally-conscious ground improvement technology capable of modifying the engineering properties of sandy soils including increases in shear stiffness and strength and decreases in hydraulic conductivity. These improvements result from the precipitation of calcium carbonate crystals at inter-particle contacts and on particle surfaces. This paper presents results from a soil column study aimed at investigating changes in soil kt during MICP treatments and subsequent desaturation using a poorly- graded sand. The results indicate that while bio-cementation can increase soil kt, the level of enhancement depends on the degree of saturation. For instance, increases of up to 330% were measured under dry conditions while only modest increases of about 15% were measured under saturated conditions. MICP treatment may therefore be most effective at enhancing the kt of partially-saturated and dry sands. In addition, the similarity between the evolution of kt and shear wave velocity (Vs) during MICP treatment suggests that kt may provide a new method to assess cementation level and contact quality.

On the Important Mechanical Properties of Rubber-Sand

2013 ◽  
Vol 685 ◽  
pp. 8-14 ◽  
Author(s):  
Korhan Adalier ◽  
Ahmet Pamuk
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Laboratory Testing ◽  
Road Construction ◽  
Sandy Soils ◽  
Environmental Hazards ◽  
High Tensile Strength ◽  
Scrap Tires ◽  
The World ◽  
Disposal Problem

More than a billion rubber tires are discarded annually around the world. Growing piles of discarded tires create fire and environmental hazards. Current disposal methods are mostly wasteful and costly. Tires possess high tensile strength, are chemically very stable, practically non-destructible and light in weight. All of these properties make tires a potentially useful geo-material. This paper presents the results of an extensive laboratory testing study investigating the potential of using shredded tires mixed with sandy soils (rubber-sand) as lightweight fill and backfill material in road construction. The results show that rubber-sand has significant promise for use as an earthwork fill material. In addition to its engineering benefits, such use of scrap tires would significantly contribute to solving the ever-growing tire disposal problem.

Influence of the Particle Size on the Flow Potential and Friction Index of Partially Saturated Sandy Soils

2021 ◽  
Author(s):  
Khayreddine Doumi ◽  
Youcef Mahmoudi ◽  
Abdellah Cherif Taiba ◽  
Wiebke Baille ◽  
Mostefa Belkhatir
Keyword(s):  
Particle Size ◽  
Sandy Soils ◽  
Partially Saturated ◽  
Flow Potential

Environmental microscopy of capillary stress-induced strain behavior in ambient-pressure aerogels

1996 ◽  
Vol 54 ◽  
pp. 850-851
Author(s):  
Sudeep M. Rao ◽  
Joshua Samuel ◽  
Sai S. Prakash ◽  
C. Jeffrey Brinker
Keyword(s):  
Silica Aerogel ◽  
Ambient Pressure ◽  
Drying Shrinkage ◽  
Pore Filling ◽  
Silica Network ◽  
Strain Behavior ◽  
Partially Saturated ◽  
Capillary Stress ◽  
Wetting Liquid ◽  
Aerogel Films

Ambient pressure silica aerogel thin films have recently been prepared by exploiting reversible drying shrinkage caused by derivatization of the internal gel surface. Aerogels have porosities of upto 99.9% and due to the small size of the pores (few nanometers), large capillary stresses are produced in gels that are partially saturated with a wetting liquid. As a result of these capillary stresses, the flexible silica network undergoes strain which has been observed using environmental microscopy. This technique allows variation of the equilibrium vapor pressure and temperature, and a simultaneous monitoring of the deformation of the unconstrained film thickness. We have observed >600% deformation during the pore-filling and pore-emptying cycles. In this presentation, we discuss the unique stress-strain behavior of these films.Ref.: Sai S. Prakash, C. Jeffrey Brinker, Alan J. Hurd & Sudeep M. Rao, "Silica aerogel films prepared at ambient pressure by using surface derivatization to induce reversible drying shrinkage", Nature. Vol. 374, 30 March, 1995, 439-443.

Assessing Sexual Dysfunction, Part 1: Male Sexual Dysfunction

2016 ◽  
Vol 21 (2) ◽  
pp. 3-8
Author(s):  
Seth D. Cohen ◽  
Steven Mandel ◽  
David B. Samadi
Keyword(s):  
Sexual Dysfunction ◽  
Health Care Professionals ◽  
Laboratory Testing ◽  
Aging Male ◽  
Testosterone Deficiency ◽  
Subjective Complaint ◽  
Validated Questionnaire ◽  
Male Sexual Dysfunction ◽  
Multiple Health

Abstract To properly assess men and women with sexual dysfunction, evaluators should take a biopsychosocial approach that may require consultation with multiple health care professionals from various fields in order to get to the root of the sexual dysfunction; this multidisciplinary methodology offers the best chance of successful treatment. For males, this article focuses on erectile dysfunction (ED) and hypogonadism. The initial evaluation of ED involves a thorough case history, preferably taken from the patient and partner, physical examination, and proper laboratory and diagnostic tests, including an acknowledgment of the subjective complaint. The diagnosis is established on the basis of an individual's report of the consistent inability to attain and maintain an erection sufficient to permit satisfactory sexual intercourse. Initial workups for ED should entail a detailed history that can be obtained from a validated questionnaire such as the International Index of Erectile Function and the Sexual Health Inventory for Men. Hypogonadism is evaluated using the validated Androgen Deficiency in the Aging Male questionnaire and laboratory testing for testosterone deficiency. Treatments logically can begin with the least invasive and then progress to more invasive strategies after appropriate counseling. The last and most important treatment component when caring for men with sexual dysfunction—and, arguably, the least practiced—is close follow-up.

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