National Bureau of Standards Gaithersburg, MD 20899 Studies of transient wave propagation in plates were carried out to establish a basis for the impact-echo technique as a nondestructive test for flaw detection in concrete. The surface displacements caused by stress waves generated by point impact on a plate were calculated using both the Green's function solution and the finite element method...

Wedge-shaped defects are frequently observed on the cervical region of the human tooth. Previously, most studies explained that improper tooth-brushing causes such defects. However, recent clinical observation suggested that the repeated stress due to occlusal force may induce the formation of these wedge-shaped defects. In this study, therefore, two-dimensional human tooth models are considere...

Presently, most microelectronic devices are fabricated using top-down approaches. According to Moore’s law, with the predicted ultimate reduction in size over the next years, these processes will reach the limits of technological instrument resolution. In addition, a major bottleneck in top-down approaches is the prohibitive cost due to the large number of technological steps required to reduce...

Injection of biomaterials into diseased myocardium has been associated with decreased myofiber stress, restored left ventricular (LV) geometry and improved LV function. However, its exact mechanism(s) of action remained unclear. In this work, we present the first patient-specific computational model of biomaterial injection that accounts for the possibility of residual strain and stress introdu...

We present a novel physically-based method to visualize stress tensor fields. By incorporating photoelasticity into traditional raycasting and extending it with reflection and refraction, taking into account polarization, we obtain the virtual counterpart to traditional experimental polariscopes. This allows us to provide photoelastic analysis of stress tensor fields in arbitrary domains. In ou...

There has been an exponential increase in the use of electronic devices over the past few decades. This has led to increased exposure to electromagnetic fields (EMF). Electric fields result from differences in voltage, whereas magnetic fields result from the flow of electric current. Higher-frequency waves of EMF have more energy than lower-frequency waves, and thus generally tend to be more ha...

background: induction of cellular response after exposure to electromagnetic fields is limited to coherent fields. an incoherent noise field is supposed to suppress the bioeffects of regular rf electromagnetic fields. the purpose of this study was to investigate the effect of gsm mobile phone-induced radiofrequency (rf) on the induction of oxidative stress in sp2/0 cell line. materials and meth...

despite a lot of efforts and investigations worldwide, dnr is still a controversial issue in many countries. in iran although significant achievements are reached in different fields; end of life care is hardly considered as a scientific necessity. development and implementation of clear policies for dnr orders is required to prevent futile prolongation of death, psychological stress to the pat...

Nanoindentation of treated surfaces, thin films, and coatings is often used as a simple method to measure their hardness stiffness. These quantities are technologically highly relevant allow qualitatively compare different material surface treatments but fail capture the entire extent complex mechanical interaction between indenter tip tested surface. Many studies have addressed this question b...