scholarly journals Long-term effect of potassium chloride treatment on improving the soil behavior of highly sensitive clay — Ulvensplitten, Norway

2016 ◽  
Vol 53 (3) ◽  
pp. 410-422 ◽  
Author(s):  
Tonje Eide Helle ◽  
Steinar Nordal ◽  
Per Aagaard ◽  
Ole Kristian Lied

Re-establishing high salt concentration in leached low-saline, highly sensitive clays significantly improves their mechanical properties. Long-term effects on quick clay exposed to diffusion of potassium chloride (KCl) from salt wells installed in 1972 at Ulvensplitten, Oslo, Norway, are investigated. The increased undrained and remolded shear strengths, as well as increased Atterberg limits, remain 30 to 40 years later. The undisturbed shear strength increased from less than 10 to 25–30 kPa, and the remolded shear strength increased from less than 0.5 to more than 6 kPa. The liquid limit increased beyond the natural water content. Adding KCl to quick clay improved the properties to such an extent that it no longer appears as quick. Recent ground investigations in the area suggest a permanent effect on an engineering time scale. Consequently, the method may be suitable to prevent large flow slides in quick clay areas.

2020 ◽  
Vol 29 (1) ◽  
pp. 205-221 ◽  
Author(s):  
David Peter Giles

AbstractThe term quick clay has been used to denote the behaviour of highly sensitive Quaternary marine clays that, due to post depositional processes, have the tendency to change from a relatively stiff condition to a liquid mass when disturbed. On failure these marine clays can rapidly mobilise into high velocity flow slides and spreads often completely liquefying in the process. For a clay to be defined as potentially behaving as a quick clay in terms of its geotechnical parameters it must have a sensitivity (the ratio of undisturbed to remoulded shear strength) of greater than 30 together with a remoulded shear strength of less than 0.5 kPa. The presence of quick clays in the UK is unclear, but the Quaternary history of the British islands suggests that the precursor conditions for their formation could be present and should be considered when undertaking construction in the coastal zone.


Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.


2020 ◽  
Vol 196 ◽  
pp. 104438 ◽  
Author(s):  
Zeli Li ◽  
Zhiguang Liu ◽  
Min Zhang ◽  
Chengliang Li ◽  
Yuncong C. Li ◽  
...  

2020 ◽  
Vol 12 (9) ◽  
pp. 3671 ◽  
Author(s):  
Chia-Lin Chang ◽  
Michael McAleer ◽  
Vicente Ramos

The SARS-CoV-2 virus that causes the COVID-19 disease is highly infectious and contagious. The long-term consequences for individuals are as yet unknown, while the long-term effects on the international community will be dramatic. COVID-19 has changed the world forever in every imaginable respect and has impacted heavily on the international travel, tourism demand, and hospitality industry, which is one of the world’s largest employers and is highly sensitive to significant shocks like the COVID-19 pandemic. It is essential to investigate how the industry will recover after COVID-19 and how the industry can be made sustainable in a dramatically changed world. This paper presents a charter for tourism, travel, and hospitality after COVID-19 as a contribution to the industry.


2016 ◽  
Vol 10 (2) ◽  
pp. 93-104
Author(s):  
Marios Hadjipavlou ◽  
Ali Tasleem ◽  
Francois Dos Santos ◽  
Daron Smith ◽  
Seshadri Sriprasad

Clinicians are faced with multiple diagnostic and treatment challenges when managing pregnant women with urolithiasis. Anatomical and physiological changes during pregnancy have to be taken into account whilst simultaneously considering both the expectant mother and the foetus. Ultrasonography remains the first-choice imaging modality, notwithstanding its potentially poor diagnostic accuracy. There is currently no consensus on second-line investigation for suspected urolithiasis. Low-dose non-contrast CT is highly sensitive, but the long-term effects of ionizing radiation on the foetus remain unknown. As far as treatment is concerned, expectant therapy is the primary option for management in the majority of cases. Percutaneous nephrostomy or ureteric stent placements are safe temporizing measures in relieving an acutely obstructed system and should be expedited in the presence of sepsis. Studies have shown ureteroscopy to be safe and effective during pregnancy with no significant risk to the foetus. It is important for the clinician to explain clearly the risks associated with the investigation and management options to the pregnant patient, including an acknowledgement that some of these remain unquantified, or even unknown.


Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.


2012 ◽  
Vol 43 (3) ◽  
pp. 42
Author(s):  
MITCHEL L. ZOLER
Keyword(s):  

VASA ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 243-249 ◽  
Author(s):  
Drinda ◽  
Neumann ◽  
Pöhlmann ◽  
Vogelsang ◽  
Stein ◽  
...  

Background: Prostanoids are used in the treatment of Raynaud’s phenomenon and acral perfusion disorders secondary to collagenosis. In subjective terms, intravenous administration of these agents produces success in more than 50% of patients. The therapeutic outcome of clinical administration of alprostadil or iloprost may vary from individual to individual. Patients and methods: The following variables were analysed in a cross-over study in 27 patients with collagenosis and Raynaud’s phenomenon: plasma viscosity and erythrocyte aggregation (rheological variables), partial pressure of oxygen and laser Doppler flowmetry in the finger region, and lymphocyte phenotyping and interleukin (IL) determinations (immunological variables). Results: Laser Doppler flowmetry revealed significant differences between patients with secondary Raynaud’s phenomenon and a control group of 25 healthy subjects. Laser Doppler readings did not change significantly as a result of the treatments. Therapy with iloprost produced a reduction in IL-1beta, L-selectin (CD 62 L) and IL-6. Conclusion: The change in immunological variables due to iloprost may explain the long-term effects of prostaglandins in the treatment of Raynaud’s phenomenon. From our results it is not possible to infer any preference for iloprost or alprostadil.


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