In the present study, base pressure variations induced by presence of a cavity, known to have strong influence behaviour supersonic projectiles, are investigated through numerical solution balance equations for mass, momentum, and energy. An area ratio four is considered simulations carried out at Mach M = 1.2, 1.4, 1.6, 1.8 assuming no cavity or locations 0.5D, 1D, 1.5D, 2D. The inlet nozzle a...

The local extension of olfactory groove meningioma into the paranasal sinuses and nasal cavity eroding underlying bone in young patients is considered as an unusual and extremely rare event. We report the case of a 25-year-old female of primary growth of olfactory groove meningioma extension to left ethmoidal sinus and nasal cavity, presented with sudden onset of seizure after delivering a baby...

The aim of this study was to assess by means of cone-beam computed tomography (CBCT) scans the transverse effects on the nasomaxillary complex in patients submitted to rapid maxillary expansion (RME) using Haas expander in comparison to untreated individuals. This prospective controlled clinical study assessed 30 subjects (18 boys and 12 girls) with mixed dentition and during pubertal growth. T...

A circular disc hitting a water surface creates an impact crater which after collapse leads to a vigorous jet. Upon impact an axisymmetric air cavity forms and eventually pinches off in a single point halfway down the cavity. Two fast sharp-pointed jets are observed shooting up- and downwards from the closure location, which by then has turned into a stagnation point surrounded by a locally hyp...

ABSTRACT In this study, the effect of cutting the end of a thick airfoil and adding a cavity on its flow pattern is studied experimentally using PIV technique. First, by cutting 30% chord length of the Riso airfoil, a thick blunt trialing-edge airfoil is generated. The velocity field around the original airfoil and the new airfoil is measured by PIV technique and compared with each other. Then,...

Some time ago the author had occasion to prepare a quantity of phenyl thio carbamide, and while placing it in a bottle the dust flew around in the air. Another occupant of the laboratory, Dr. C. R. Noller, complained of the bitter taste of the dust, but the author, who was much closer, observed no taste and so stated. He even tasted some of the crystals and assured Dr. Noller they were tasteles...

Existing theories describe corrosive wear in crosshead diesel engines in terms of acid condensation, when the temperature in the combustion space drops below the dew point. Here a theory is proposed which stresses the role of alkaline cylinder lubricants in protecting the metal surface. Calculated liner wear rates as a function of fuel sulphur content, feed rate and alkalinity of the oil, and a...

Changes in cultivable flora in dentine samples collected before and after hand excavation were examined in association with clinical status of the cavity surface, light microscopy and scanning electron microscopy (SEM). Thirty-five extracted permanent molar teeth with an occlusal caries lesion were excavated with hand instruments according to the atraumatic restorative treatment (ART) approach....

Wake "eld e!ects driven by a coasting relativistic charged particle beam have been studied for various cavity geometries. In the particular case of a cylindrical `pill-boxa cavity, an analytical expression of the (E, B)(x, t) map has been obtained as a development on the complete base cavity normal modes. We extend this method to the case of an accelerated beam, which leaves the downstream face...

Objective. Although several therapeutic strategies have proven to be effective for hydatid cyst of liver, but surgery is still the most common therapy despite its morbidity and mortality. Furthermore, a variety of technique has been recommended for managing the residual cavity after cystectomy. We report here a new technical method for the reconstruction of hydatid cyst residual cavity with usi...