PURPOSE A primary task of the eye care professional is determining the refraction, or optical correction, of a patient. The duochrome red-green test is a standard tool for verification of the final refraction. Traditionally, it is recommended for use both prior to and subsequent to determining the cylindrical or astigmatic component of the refraction. In order for it to be effective when used b...

Abstract In this study, the optical diagnostics techniques of infrared (IR) absorption and chemiluminescence were applied to a racing engine. A small M5 IR sensor and Cassegrain optics sensors were developed to measure in-cylinder fuel concentrations and local chemiluminescence intensities. The small IR sensor was able to withstand racing engine operating conditions up to 16,000 rpm and exhibit...

INTRODUCTION In scuba-diving practice, instantaneous gas consumption is generally calculated from the fall in cylinder pressure without considering the effects of water temperature (heat transfer) and adiabatic processes. We aimed to develop a simple but precise method for calculating the instantaneous gas consumption during a dive. METHODS With gas thermodynamics and water/gas heat transfer,...

Due to the complex geometry and thermos-mechanical loading, cylinder heads are the most challenging parts among all parts engines. They must endure cyclic thermal and mechanical loading throughout their lifetime. Cast aluminum alloys are normally quenched after solution treatment process to improve aging responses. Rapid quenching can lead to high residual stress. Residual stress is one of the ...

BACKGROUND For many long standing practices, the rationale for them is often lost as time passes. This is the situation with respect to the storage and handling of equimolar 50% nitrous oxide and 50% oxygen volume/volume (v/v) mixtures. METHODS A review was undertaken of existing literature to examine the developmental history of nitrous oxide and oxygen mixtures for anesthesia and analgesia ...

The gripper cylinder that provides braced force for Tunnel Boring Machine (TBM) might fail due to severe vibration when the TBM excavates in the tunnel. Early fault diagnosis of the gripper cylinder is important for the safety and efficiency of the whole tunneling project. In this paper, an online condition monitoring system based on the Empirical Mode Decomposition (EMD) method is established ...

The flow interception efficiency, which provides a measure of the fraction of streamlines that intercept a porous collector, is an important parameter in applications such as particle capture, filtration, and sedimentation. In this work, flow permeation through a porous circular cylinder located symmetrically between two impermeable parallel plates is investigated numerically under different fl...

The rich variety of densest columnar structures of identical hard spheres inside a cylinder can surprisingly be constructed from a simple and computationally fast sequential deposition of cylinder-touching spheres, if the cylinder-to-sphere diameter ratio is D is an element of [1,2.7013]. This provides a direction for theoretically deriving all these densest structures and for constructing such...

Backscattering enhancement phenomenon in a random medium is studied by numerically analyzing a bistatic radar cross-section of a circular cylinder, under the condition that the spatial coherence length of the incident waves around the cylinder is larger enough than the size of the cylinder. The numerical analysis shows that the phenomenon may occur not only in the backward direction but also in...

The scattering enhancement phenomenon is studied by numerically analyzing a bistatic radar cross-section (RCS) of a circular cylinder in a strong continuous random medium, under the condition that the spatial coherence length of the incident waves around the cylinder is larger enough than the size of the cylinder. The numerical analysis shows such a new result that the scattering is not enhance...