leiomyoma is a rare esophageal tumor that constitutes less than 1% of esophageal malignancies. it should be removed when diagnosed even if asymptomatic. this study presents two cases of esophageal leiomyoma in 38 and 62 years old men who presented with dysphagia and evaluated for diagnosis and location of related tumors. patients were clinically examined and upper gastrointestinal endoscopy, ch...

This paper presents the design optimization of diaphragms for a micro-shock tube-based drug delivery device. The function of the diaphragm is to impart the required velocity and direction to the loosely held drug particles on the diaphragm through van der Waals interaction. The finite element model-based studies involved diaphragms made up of copper, brass and aluminium. The study of the influe...

The extremely rapid reflection of a shock wave from the end wall generated in tube, addition to high-frequency content pressure, inevitably also excites mechanical vibrations. These can potentially produce acceleration-induced spurious signals as part dynamic output pressure measurement system being calibrated. This paper proposes and evaluates method for correcting frequency response obtained ...

Introduction: In radiotherapy treatment planning system (TPS), basic input is the data from computed tomography (CT) scan, which takes into account the effect of inhomogeneities in dose calculations. Measurement of CT numbers may be affected by scanner-specific parameters. Therefore, it is important to verify the effect of different CT scanning protocols on Hounsfield unit (HU) and its impact o...

SUMMARY The free piston compreeslon shock tube provIdea a simple means of obtaining shock Mach numbers of the order of 30. This paper concerns the design and development at Cranfteld of such a shock tube. The problem6 encountered in evolving a pwton capable of withstanding heavy impacts at the completion of 50s stroke are outlined, and some preliminary shock tube perfonnanoe data given.

The end plate mounted at the mouth of the shock tube is a versatile and effective implement to control and mitigate the end effects. We have performed a series of measurements of incident shock wave velocities and overpressures followed by quantification of impulse values (integral of pressure in time domain) for four different end plate configurations (0.625, 2, 4 inches, and an open end). Sho...

A cryogenic shock tube has been developed as a tool for research in fluid mechanics and low-temperature physics. The shock tube was designed to operate with the test section immersed in a cryogenic liquid. A unique diaphragm-changing mechanism makes this shock tube an economical and practical device. There are several advantages in operating a shock tube at cryogenic temperatures. Shock waves o...

Formation of vortex rings at the exit of a shock tube is studied theoretically. A model for predicting the maximum circulation that a vortex ring can attain at the exit of a shock tube is offered. To achieve maximum circulation the initial conditions and the design of the driver and driven sections must be such that the generated shock wave reaches the shock tube exit at least 4Dn/^2 time units...

In this paper, the behavior of shock wave discharged from the pipe end is studied. The shock wave is generated using the shock tube (MO-tube). The flow field while the shock moves downstream is visualized using shadow photography and schlieren photography. The propagation of shock wave and the phenomenon of the occurrence of second vortex ring are examined and discussed.