Due to a distinct nature of thermomechanical smart materials' reaction to applied loads, a revolutionary approach is needed to measure the hardness and to understand its size effect for pseudoelastic NiTi shape memory alloys (SMAs) during the solid-state phase transition. Spherical hardness is increased with depths during the phase transition in NiTi SMAs. This behaviour is contrary to the decr...

We have investigated the effect of pressure and thermal ageing on transformation behavior of Ni-%45.16Ti shape memory alloy. 70-320 MPa pressure was applied and annealed at 500 o C for 2 hour to see the effect of applied pressure on transformation temperature. It was observed that the starting and final temperature of austenit increased, the martensite start temperature almost remain constant a...

The non-linear nature of the superelastic phase transformation in NiTi means that conventional fatigue life theory is difficult to apply. The volume fraction of martensite/parent phase and its role in the fatigue mechanism is not understood. This paper considers the fatigue life of superelastic NiTi alloys when tested at 2Hz in Ringers solution. In agreement with other researchers [1] [2] it wa...

BACKGROUND/AIM The aim of this study was to evaluate the transesophageal echocardiography (TEE) findings of pediatric patients in a tertiary center where complex congenital heart surgery and interventional procedures have been performed. MATERIALS AND METHODS All TEE studies performed between December 2009 and December 2014 were reviewed retrospectively. Patients were divided into 3 groups: p...

ba ckground: although it is widely accepted that the pre-school age is a critical period  in  the  development of  obesity,  there  are  few  published data  on  factors contributing to variation of total energy expenditure in this age group.to investigate the contribution of body composition, gender and activity on total energy expenditure (tee) in pre-school children. m ethods: the total ener...

Background. During the past few years, transesophageal echocardiography (TEE) has been increasingly used in clinical cardiology; data concerning the practicability and safety of the technique, however, are rare. Methods and Results. This report analyzes the experience of 15 European centers performing TEE studies for at least 1 year. At the time of this survey, 10,419 TEE examinations had been ...

Transesophageal echocardiography (TEE) is not only an invaluable diagnostic tool for cardiac patients, but also is essential for cardiac monitoring in critically ill patients in cardiac and non-cardiac surgery settings and in the differential diagnosis of unexplained hemodynamic collapse. The advantage of TEE over transthoracic echocardiography (TTE) is usually clearer images, especially when v...

Phase shift versus control voltage for bridged-tee phase modulator {f—7}250 he). work during modulation is not generally serious, since the input reactance of the network decreases to only — j4:Xc/S ohms when R2 becomes zero. Another application of the bridged-tee of figure 3 is suggested by the previously mentioned property of this network of giving constant attenuation with variation in frequ...

Since the introduction of engine-driven nickel-titanium (NiTi) instruments, attempts have been made to minimize or eliminate their inherent defects, increase their surface hardness/flexibility and also improve their resistance to cyclic fatigue and cutting efficiency. The various strategies of enhancing instrument surface include ion implantation, thermal nitridation, cryogenic treatment and el...