In this paper the effect of random geometric imperfections on the critical load of isotropic, thin-walled, cylindrical shells under axial compression with rectangular cutouts is presented. Second moment characteristics of geometric imperfections are estimated by data of available measurements, a simulation procedure based on the Karhunen-Loève expansion is applied for generating realizations of...

In this work, we subject bi- and terpyrenyls to selective fusion for formation of extended polycyclic aromatic hydrocarbons (PAHs). Connecting the pyrene units at 4-4'- or 1-4'-positions led to smooth formation of extended PAHs, achieved via cyclodehydrogenation. This is far more difficult if pyrene is coupled in the 1,1'-position.

Objective: To determine whether the use of a gel pillow with side cutouts designed to accommodate a continuous positive airway pressure (CPAP) mask and reduce head temperature improves the efficacy of and adherence to auto-CPAP therapy. Methods: Twenty-three consecutive CPAP-naïve patients with obstructive sleep apnea were enrolled in the study. Patients were given an auto-CPAP machine with a...

ABSTRACT Defeaturing is a popular CAD/ CAE simplification technique where ‘small or irrelevant features’ are suppressed within a CAD model for speeding-up downstream processes, especially finite element analysis. Unfortunately, defeaturing also results in analysis errors that are not easily quantifiable within the current theoretical framework. In this paper, we provide a rigorous theory for sw...

OBJECTIVE This clinical study investigated the effects of an individually fabricated prone positioner on heart rate, respiratory rate, and scapular position of premature infants in the neonatal intensive care unit. The prone positioner consisted of dense foam with cutouts to position the shoulders forward and toward midline. METHOD Six measurements of scapular rotation, respiratory rate, hear...