Results 271 to 280 of about 760,552 (308)

Oxidative stress assessment by a spectroscopic approach in pomegranate plants under a gradient of ozone concentrations

Environmental and Experimental Botany, 2021
Abstract Techniques to monitor oxidative stress pre-visually are essential to optimize plant management. Here, we investigated the capability of hyperspectral reflectance (350−2500 nm) to characterize responses of two pomegranate cultivars (Parfianka and Wonderful) under ozone (O3) episodes at a gradient of concentrations (50, 100 and 200 ppb for 5 h)
Calzone A., Cotrozzi L., Remorini D., Lorenzini G., Nali C., Pellegrini E.   +5 more
openaire   +1 more source

Non-local stress approach to fracture initiation in laboratory experiments with a tensile stress gradient

Mechanics of Materials, 2001
The paper discusses the stress distribution and the fracturing in diametrically loaded discs in which a hole has been drilled at some distance from the loaded diameter. A linear elastic analysis of the problem indicates that the maximum tensile stress at the hole is up to four times the tensile stress along the loaded diameter.
B. Van de Steen, A. Vervoort
openaire   +1 more source

A New Approach to Evaluate Steep Stress Gradients Principally Using Layer Removal

Materials Science Forum, 2000
A new method is, reported to determine a triaxial residual stress (RS) profile as a function of the distance z from the surface from experimental X-ray data for several penetration depths T without using a Laplace transformation explicitly. The method is based on the fact, that if stress states in a thin layer vary linearly over the depth of the ...
V. Hauk, B. Krüger
openaire   +1 more source

Consideration of stress gradient effects for complex structures in local fatigue approaches

2015
The assessment of the fatigue strength by means of local approaches is very conservative compared with experiments of complex plated structures connected by welded joints. Here, relatively long crack propagation phases were observed. At first, this paper deals with numerical crack propagation simulations which were performed for different geometrical ...
Fischer, Claas, Fricke, Wolfgang
openaire   +2 more sources

Stress and stress gradient evaluation — a BEM approach

Advances in Engineering Software, 1994
This paper reviews the current methods for boundary stress evaluation by the boundary element method, and derives a formula for the stress gradient on the boundary. A simple post processing scheme is presented, which uses stress continuity and stress gradient continuity along a traction boundary as two extra conditions, so that a high order shape ...
openaire   +1 more source

A Direct Micromechanical Approach toward the Development of Quadratic Stress Gradient Failure Criteria for Textile Composites

Journal of Composite Materials, 2006
Based upon previous results of direct micromechanical method (DMM) analysis of the representative volume element (RVE) of a plain-weave textile composite, two methods for predicting failure envelopes are presented: a parametric ellipse-fitting scheme, and a 27-term quadratic stress-gradient failure criterion.
Ryan L. Karkkainen, Bhavani V. Sankar, Jerome T. Tzeng   +2 more
openaire   +1 more source

Practical approach to gradient direction sensor method in very large scale integration thermomechanical stress analysis

Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2006
Silicon integrated sensors for thermomechanical stress measurement in very large scale integration (VLSI) has been studied extensively in recent years due to the increasing complexity of modern semiconductor devices. As the chip size has increased continuously to accommodate more functions in modern integrated circuits (IC) technology, the stress ...
Ahmed Lakhsasi, Mohammed Bougataya, Daniel Massicotte   +2 more
openaire   +1 more source

A new approaching method to estimate fracture gradient by correcting Matthew–Kelly and Eaton's stress ratio

Journal of Petroleum Science and Engineering, 2015
Abstract Fracture pressure is one of the most important parameters in wellbore stability. Fracture pressure shows the ability of rock to hold vertical stress before starts to fracture. The application of fracture gradient (FG) affects the well design, such as mud weight profile, casing setting depth, and cementing operation.
Bonar Tua Halomoan Marbun, Anisa Noor Corina, Gde Valdy Arimbawa, Ramadhana Aristya, Sigit Purwito, Aldiano Falah Hardama   +5 more
openaire   +1 more source

Fatigue from defect under multiaxial loading: Defect Stress Gradient (DSG) approach using ellipsoidal Equivalent Inclusion Method

International Journal of Fatigue, 2014
Abstract The fatigue design of metallic parts depends on the casting process. It requires a compromise between the fatigue resistance of the component and the allowable defect size due to the process. The research team has proposed, in previous work [Leopold G, Nadot Y.
M. Vincent, C. Nadot-Martin, Y. Nadot, A. Dragon   +3 more
openaire   +1 more source

A Novel Semi-Analytical Approach for Micro Beams Subjected to Electrostatic Loads and Residual Stress Gradients

Volume 6: ASME Power Transmission and Gearing Conference; 3rd International Conference on Micro- and Nanosystems; 11th International Conference on Advanced Vehicle and Tire Technologies, 2009
Beam structures are widely used in MEMS sensors and actuators. MEMS micro beams are usually curled due to residual stresses and the characteristics of micro beams subjected to both residual stress gradients and electrostatic forces must be investigated for providing accuracy information for designing sensors and actuators.
Kuang-Shun Ou, Kuo-Shen Chen, Tian-Shiang Yang, Sen-Yung Lee   +3 more
openaire   +1 more source