scholarly journals The Effects of Seasonal Thermal Loads at Expansion Joints Locations in Arabic Area Buildings

2019 ◽  
Vol 9 (1) ◽  
pp. 1919-1925
Keyword(s):  
Structural Deformation ◽  
Seasonal Temperature ◽  
Thermal Loads ◽  
Long Term Effects ◽  
Expansion Joints ◽  
Thermally Induced ◽  
Structural Engineer ◽  
Temperature Loads ◽  
Concrete Elements

Concrete buildings are subjected to fluctuation in seasonal temperature loads between summer and winter in the Arabic area. The long-term effects on buildings of such temperatures, along with the frequent fluctuation in the seasonal temperatures impose overall structural deformation, displacements, and alteration of stresses in concrete elements. The thermally induced deformations affect the serviceability conditions of buildings with time. Concrete creep and shrinkage will increase the cracks widths and the imposed stresses too. To eliminate this phenomenon effects, expansion joints should be provided. However, as per the buildings functions and trend to develop unique buildings by designers, joint-less buildings are usually the preferred option. When using this option, the structural engineer has to consider the effects of thermal loads changes in the design. Clear rules and standards must be provided to define the maximum joints spacing’s allowed length in addition to thermal study procedures. Different approaches are provided by researchers, each methodology provide different value for required joints spacing considering different aspects in design. In this paper I shall try to present three methods with comparison study for considered aspects and gaps for each method analysis to propose the most appropriate methodology as a tool helps engineers in calculating the maximum allowed spacing between expansion joints

scholarly journals The Effects of Seasonal Thermal Loads at Expansion Joints Locations in Arabic Area Buildings

2019 ◽  
Vol 8 (11S2) ◽  
pp. 406-412
Keyword(s):  
Structural Deformation ◽  
Seasonal Temperature ◽  
Thermal Loads ◽  
Long Term Effects ◽  
Expansion Joints ◽  
Thermally Induced ◽  
Structural Engineer ◽  
Temperature Loads ◽  
Concrete Elements

Concrete buildings are subjected to fluctuation in seasonal temperature loads between summer and winter in the Arabic area. The long-term effects on buildings of such temperatures, along with the frequent fluctuation in the seasonal temperatures impose overall structural deformation, displacements, and alteration of stresses in concrete elements. The thermally induced deformations affect the serviceability conditions of buildings with time. Concrete creep and shrinkage will increase the cracks widths and the imposed stresses too. To eliminate this phenomenon effects, expansion joints should be provided. However, as per the buildings functions and trend to develop unique buildings by designers, joint-less buildings are usually the preferred option. When using this option, the structural engineer has to consider the effects of thermal loads changes in the design. Clear rules and standards must be provided to define the maximum joints spacing’s allowed length in addition to thermal study procedures. Different approaches are provided by researchers, each methodology provide different value for required joints spacing considering different aspects in design. In this paper I shall try to present three methods with comparison study for considered aspects and gaps for each method analysis to propose the most appropriate methodology as a tool helps engineers in calculating the maximum allowed spacing between expansion joints.

scholarly journals The Effect of Temperature Variation on Bridges—A Literature Review

2021 ◽  
pp. 207-212
Author(s):  
Sushmita Borah ◽  
Amin Al-Habaibeh ◽  
Rolands Kromanis
Keyword(s):  
Temperature Variation ◽  
Thermal Load ◽  
Effect Of Temperature ◽  
Seasonal Temperature ◽  
Complex Load ◽  
Thermally Induced ◽  
Seasonal Temperature Variation ◽  
Static And Dynamic Loads ◽  
Temperature Responses

AbstractBridges are commonly subjected to complex load scenarios in their lifetime. Understanding the response of bridges under such load scenarios is important to ensure their safety. While static and dynamic loads from vehicles and pedestrians influence the instantaneous response of bridges, studies show that thermal load from diurnal and seasonal temperature variation influences its long-term response and durability. This study addresses the effects of thermal load variation on bridges and briefly reviews methods of measuring such effects. The findings show that thermally induced deformations in bridges are of magnitude equal or larger than that induced by vehicle induced load. This study highlights the significance of measuring temperature responses of bridges for their robust structural health monitoring.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

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.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

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.

Long-Term Effects of Head Lice Tx Unknown

2012 ◽  
Vol 43 (3) ◽  
pp. 42
Author(s):  
MITCHEL L. ZOLER
Keyword(s):  
Head Lice ◽  
Long Term Effects

The response of skin perfusion and of rheological and immunological variables to intravenous prostanoid administration in Raynaud’s phenomenon secondary to collagenosis

VASA ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 243-249 ◽  
Author(s):  
Drinda ◽  
Neumann ◽  
Pöhlmann ◽  
Vogelsang ◽  
Stein ◽  
...  
Keyword(s):  
Laser Doppler Flowmetry ◽  
Raynaud’S Phenomenon ◽  
Raynaud's Phenomenon ◽  
Plasma Viscosity ◽  
Laser Doppler ◽  
Erythrocyte Aggregation ◽  
Control Group ◽  
Long Term Effects ◽  
Doppler Flowmetry

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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