THE PRINCIPLE of maximum energy dissipation rate is introduced as an energy criterion for crack dynamics. That allows us to explain observed limiting crack speeds in brittle materials, and to complete the crack dynamics formulation. The upper limits of the crack speed in perfectly elastic and elastic-plastic bodies are obtained. It is found that the theoretical maximum crack speed in an isotrop...

Mechanical stresses from wind, current or wave action can strongly affect plant growth and survival. Survival and distribution of species often depend on the plant's capacity to adapt to such stresses, particularly when amplified by climatic variations. Few studies have dealt with plastic adjustments in response to mechanical stress compared to resource stress. We hypothesized that mechanical s...

INTRODUCTION Relative value units (RVUs) were developed as a quantifier of requisite training, knowledge, and technical expertise for performing various procedures. In select procedures, increasing RVUs have been shown to substitute well for increasing surgical complexity and have been linked to greater risk of complications. The relationship of RVU to outcomes has yet to be examined in the pla...

Background. The goals of this project were to evaluate the current perspective on letters of recommendation and to assess the need for, and acceptance of, a more standardized letter of recommendation (LOR). Methods. An eight-question survey was distributed to plastic surgery program directors. A five-point Likert scale was selected as a means of quantifying the participants' responses to the su...

Many beginning writers, especially medical residents, feel difficulties in writing journal articles. However, illogical and un-scientific papers are not accepted for publication even if their topics are creative and interesting. The authors should do their best to convince reviewers and readers of their opinions using evidence through reasoning, explanation, and data interpretation. The aim of ...

BACKGROUND Various studies have been conducted in many countries to determine the perception/awareness about plastic surgery. The present study assessed the views of college students about plastic surgery. METHODS A questionnaire consisted of nine questions regarding the basic knowledge about plastic surgery was randomly distributed among college students. The students were given 20 minutes t...

s. We have studied phonon hole burning phenomenon. According to the plastic deformation model proposed by us, some characteristics of holes depend on the amplitude of resonant oscillation exited and the crystal condition of specimen. We studied the effect of heat treatment for the particles on holes. In NH4HZP04 specimen, the increase of decay time for oscillation and larger holes were found. N...

Background A pulse oximeter is one of the most important monitors to save patients undergoing anesthesia and monitored sedation. The authors report a case of orthopedic surgery, in which interference of pulse oximetry occurred when using a Stealth Station™ navigation system (Medtronic Sofamor Danek, Memphis, TN). Applying a black plastic shield (Masimo Ambient Shield: Masimo Corporation, Irvine...

The impedance mismatch technique has been used for shock pressure amplification in two and three layer thin planar foil targets. Numerical simulation results using one dimensional radiation hydrocode MULTI in two layer targets consisting of Al-Au & Al-Cu and three layer target consisting of Plastic Al -Au & Foam-Al-Au respectively are presented. These results show a pressure enhancement up to 2...

Recently, there has been increasing interest in object imaging and detection behind obscuring layers because of applications in detection of improvised explosive devices (IEDs) and suspicious materials. Millimeter (MMW) and terahertz waves show promise in detecting and imaging objects through clothing or packaging materials. In this paper, we discuss an electromagnetic model based on a multi-la...