Results 271 to 280 of about 1,360,531 (316)

The positivity ratio and functioning under stress

Stress and Health, 2010
AbstractThe positivity ratio reflects the ratio of positive affect to negative affect. In two studies, the authors investigated the relationship between positivity ratio and functioning under stress. Study 1 examined gastric cancer patients (N = 123) and Study 2 explored hospital personnel exposed to missile attacks (N = 84). In both studies, there was
Amit Shrira, Yuval Palgi, Jonathan Jacob Wolf, Yeela Haber, Orit Goldray, Einat Shacham‐Shmueli, Menachem Ben‐Ezra   +6 more
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Privation, stress, and human sex ratio at birth

Early Human Development, 2015
This article reviews the growing interdisciplinary literature on the effect of privation and stress on human sex ratio at birth. Borrowing strength from the potential outcomes causal analysis framework, the discussion focuses on the issues of study design and identification strategy and how they have influenced the current state of the field.
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The effect of Poisson's ratio on stress concentrations

The Journal of Strain Analysis for Engineering Design, 2007
In design, it is common to use values for stress concentration factors (SCFs) obtained from textbooks. These textbook values have generally been obtained from photoelastic experiments for which Poisson's ratio will probably have a value greater than 0.3 and for frozen stress analysis a value approaching 0.5.
R J Grant, M Lorenzo, J Smart
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Significance of the taurine-glycine ratio as an indicator of stress

Bulletin of Environmental Contamination and Toxicology, 1987
For the quantification of stress effects, several methods and systems have been developed. Among others, biochemical techniques seem to be very promising. The following paper deals with the applicability of the taurine-glycine ratio as a biochemical stress index.
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Probabilistic Horizontal Stress Ratios in Rock

Mathematical Geology, 2002
Prior to excavation, any point in a rock mass is subjected to stress, which has to be considered in the overall stress distribution after the excavation work is completed. Over the past three decades, empirical, analytical, and field studies have shown that the ratio of average horizontal stress to vertical stress plays a dominant role in engineering ...
Zekai Şen, Bahaaeldin H. Sadagah
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Stress Ratio and Stress Trajectory Simulations for Devonian Gas Shales

SPE Unconventional Gas Recovery Symposium, 1984
ABSTRACT A brief review of selected in situ stress studies is presented. Pertinent geomechanical factors and rationale for stress trajectory characterizations are discussed in the context of natural fracturing in geological formations. Examples with structural cross sections incorporating the influence of the Rome Trough are identified ...
S.H. Advani, Anthony Andrews, J.K. Lee, C.A. Komar   +3 more
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The effects of stress ratio on fatigue threshold

International Journal of Fatigue, 1990
Abstract Arising from the fact that there is a reverse compression stress around a fatigue crack, it is supposed that there is an equivalent compressive high-strain area. Based upon the eigenequation of crack growth, the critical value, K th c , of the compressive stress intensity factor is derived.
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Effect of stress ratio on the fatigue behaviour of compact bone

Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 2005
During the fatigue process of bone, cracks generally initiate from the inherent defects existing in the bone. The fatigue lives of bone specimens at different stress levels as well as at different stress ratios R were evaluated using a computer simulation in which the crack propagation behaviour initiated from the inherent defects ...
M, Ota, S, Ishihara, C, Fleck, T, Goshima, D, Eifler   +4 more
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Stress ratio contributes to fatigue crack growth in dentin

Journal of Biomedical Materials Research Part A, 2005
AbstractAn experimental study of fatigue crack growth in dentin was conducted, and the influence of stress ratio (R) on the crack growth rate and mechanisms of cyclic extension were examined. Double Cantilever Beam (DCB) fatigue specimens were sectioned from bovine molars and then subjected to high cycle fatigue loading (105 < N < 106) under ...
D, Arola, W, Zheng, N, Sundaram, J A, Rouland   +3 more
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Stress Ratio Effects on Collapse of Compacted Clayey Sand

Journal of Geotechnical Engineering, 1991
A“double‐triaxial” test procedure similar to the double‐oedometer test was developed to determine the wetting‐induced collapse potential of soils subjected to anisotropic stress states. Based on a series of double‐triaxial tests performed on a slightly expansive clayey sand, it was established that the magnitude of volumetric strain resulting from a ...
E.C. Lawton, R.J. Fragaszy, J.H. Hardcastle   +2 more
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