Pressure control valve (PCV) is implemented in internal combustion engine to regulate crankcase pressure. In this study, the performance of a diaphragm PCV valve is investigated numerically and experimentally. Firstly, numerical simulation is carried out using commercial code to predict the flow and pressure distribution inside the valve. Furthermore, downstream and upstream pressure of the val...

This paper presents a failure analysis on a failed intake valve in a gasoline engine. During an endurance test, an intake valve was broken and caused some damages on the piston. Material examinations (by a light microscope and also a scanning electron microscope) were conducted on the fracture surface of the intake valve shaft. Results showed that no pores or defects could be observed and the m...

Mechanical processes underlying pharyngeal closure have not been examined. We hypothesized that the pharyngeal mucosal surface would fold during closure, and lowering the upper airway lining liquid surface tension would unfold areas of mucosal apposition, i.e., folds. We compared baseline pharyngeal fold numbers and response to reduction in upper airway liquid surface tension in healthy and obs...

Velopharyngoplasty (VPP) and tonsillectomy (TE) have been used for the surgical correction of velopharyngeal incompetence (VI) and its associated speech impairments, which include rhinolalia, rhinophonia, and nasal snorting. Performing the procedures together during the same operative session has been shown, on a limited basis, to offer some benefits to the primarily juvenile patient population...

The usefulness of the Coloscreen VPI test kit in occult blood detection has been examined and compared with our current method. The results show the Coloscreen procedure to be a simple, sensitive method that is much less subject to vegetable peroxidase interference than are other available screening procedures.

INTRODUCTION Surgical treatment of velopharyngeal insufficiency (VPI) in 22q11.2 deletion syndrome is often warranted. In this patient population, VPI is characterized by poor palatal elevation and muscular hypotonia with an intact palate. We hypothesize that 22q11.2 deletion patients are at greater risk of obstructive sleep apnea (OSA) after surgical correction of VPI, due, in part, to their f...

BACKGROUND Maxillary hypoplasia refers to a deficiency in the growth of the maxilla commonly seen in patients with a repaired cleft palate. Those who develop maxillary hypoplasia can be offered a repositioning of the maxilla to a functional and esthetic position. Velopharyngeal dysfunction is one of the important problems affecting speech after maxillary advancement surgery. The aim of this stu...

The main purpose of this paper is to study various configurations of a magnetorheological (MR) damper valve and to evaluate their performance indices typically dynamic range, valve ratio, inductive time constant and pressure drop. It is known that these performance indices (PI) of the damper depend upon the magnetic circuit design of the valve. Hence, nine valve configurations are considered fo...