Simulation models for unitary air conditioners and heat pumps usually can not provide accurate predictions in the case of two-phase refrigerant entering the compressor or fixed-area expansion device. This paper focuses on improving modeling methods in these situations. The study utilized extensive laboratory tests and detailed modeling of two unitary air conditioners, one using R-410A and the o...

A fundamental problem with measurements of alpha activity on air filters from the nuclear workplace is that the calibration sources used with radioactivity-in-air monitors are not in the same physical form as actual samples. The samples suffer from alpha absorption due to effects such as self-attenuation within the radioactive particle, entrapment of the particle within the filter, and the accu...

This work evaluates proposed methods to correct engine power output as a function of atmospheric conditions. The analysis was made through experiments carried out in a vehicle on the road, under different temperature, pressure and air humidity conditions. The vehicle had a four-cylinder gasoline-fuelled engine, with multi-point fuel injection system, variable intake pipe length and variable int...

In air traffic management (ATM) all necessary operations (tactical planing, sector configuration, required staffing, runway configuration, routing of approaching aircrafts) rely on accurate measurements and predictions of the current weather situation. An essential basis of information is delivered by weather radar images (WXR), which, unfortunately, exhibit a vast amount of disturbances. Thus,...

The spherical aberration generated when focusing from air into another medium limits the depth at which ultrafast laser machining can be accurately maintained. We investigate how the depth range may be extended using aberration correction via a liquid crystal spatial light modulator (SLM), in both single point and parallel multi-point fabrication in fused silica. At a moderate numerical apertur...

A method to determine the economic cost of gas turbine compressor fouling was developed. The method is based on the calculation of the influence of the drop of compressor performances (isentropic efficiency, pressure ratio and air mass flow) on Heat Rate and full load power of the gas turbine. A statistical procedure to quantify the drop of compressor performances with fouling and to obtain amb...

THE REPAIR of atrial septal defects was first undertaken over a decade ago.1'Although secundum-type defects could be closed adequately without the use of cardiopulmonary bypass, it soon became apparent that defects of the endocardial cushion type were not am-enable to correction by indirect technies.5 Accordingly, the need arose to differentiate these two lesions; the clinical, electrocardiogra...

The aim of the present study was to estimate the wall effect of the self-made spherical graphite-walled cavity chamber with the Monte Carlo method for establishing the air-kerma primary standard of high-dose-rate (HDR) ¹⁹²Ir brachytherapy sources at the Institute of Nuclear Energy Research (INER, Taiwan). The Monte Carlo method established in this paper was also employed to respectively simulat...

The current standard procedure for aligning thermal imagery with structure-from-motion (SfM) software uses GPS logger data for the initial image location. As input data, all thermal images of the flight are rescaled to cover the same dynamic scale range, but they are not corrected for changes in meteorological conditions during the flight. This standard procedure can give poor results, particul...

A IR or atmospheric pollution problems have increased many fold during the past few decades. Air pollution and its control have grown t o become factors of tremendous importance to the economy and health of many industrialized and urbanized communities. Air pollution has been defined as the excessive concentration of foreign matter in the air which adversely affects the well being of the indivi...