The Eucalyptus grandis logs temperatures were determined and correlated with the board's cracks during steaming. Thermocouples were inserted in the logs center, registering their temperatures during steaming at 90°C. The logs were sawed and the board's cracks measured. It was concluded that: (1) the logistic S-shaped curve explains the logs temperature variation; (2) the logs with diameter of 2...

The paper reviews the potential of the ultrasonic small incidence method of testing, which enables us to characterize smaller tight cracks quantitatively under load-free conditions. Recently, an important characteristic of the method of being capable of evaluating the cracks from both the accessible and inaccessible sides of material structures with almost similar level of sensitivity, has been...

this paper identifies eleven types of asphalt pavement distress types, commonly occuring in tehran metropolitan area. of these, five distresses namely: corrugation; utility cut depression ;pot holes; alligator cracking; and loss of bridge deck surfacing are rather common. however, others namely: shear failure; shrinkage cracks; lane joint cracks; bleeding; and shoulder distress are less prevail...

Usually ultrasonic techniques tend to evaluate the closed cracks as smaller than the actual size. In this paper, we describe two strategic techniques for accurately evaluating the closed cracks by means of ultrasound. First, we show the advanced technique utilizing the thermal stress induced by cooling a cracked part. It is shown that a small amount of temperature decrease is effective to open ...

The boundary value problem for the Laplace equation outside several cracks in a plane is studied. The jump of the solution of the Laplace equation and the boundary condition containing the jump of its normal derivative are specified on the cracks. The problem has unique classical solution under certain conditions. The new integral representation for the unique solution of this problem is obtain...

Visual inspection by a human operator has been mostly used up till now to detect cracks in sewer pipes. In this paper, we address the problem of automated detection of such cracks. We propose a model which detects crack fractures that may occur in weak areas of a network of pipes. The model also predicts the level of dangerousness of the detected cracks among five crack levels. We evaluate our ...

We investigate the weakening of elastic materials through randomly distributed circles and cracks numerically and compare the results to predictions from homogenization theories. We find a good agreement for the case of randomly oriented cracks of equal length in an isotropic plane-strain medium for lower crack densities; for higher densities the material is weaker than predicted due to precurs...

A computer vision system was used to evaluate seed coat and cotyledon cracks in soybeans. White light in the front-lighting mode with a black background for the soybeans was the best condition for acquiring video images of soybeans suitable for subsequent processing. Image processing algorithms were developed using the software supplied with the vision system computer. Crack detection was most ...

Topological rigidity is an analogue of the Baum-Connes conjecture, and is motivated by Mostow rigidity and Margulis superrigidity. I will discuss some of the places where this heuristic reasoning fails, and the rigidity shows some cracks – that are rather different than the places where strong forms of the Baum-Connes conjecture fails.