The enhancement of the thermal performance of Vacuum Tube Solar Collectors (VTSC) was studied by using alumina nanofluid as working fluid. VTSC is a simple and commonly utilized type of collector. This study established the heat transfer experimental model of all glass VTSCs used in a forced-circulation solar water heating system using alumina nanofluid as base fluid. Al2O3 (with an average par...

We present the growth of single wall carbon nanotubes (SWCNTs) from organic solvents such as benzene and toluene inside a host SWCNT. The solvents encapsulated in SWCNTs are transformed to an inner tube when subject to a heat treatment under dynamic vacuum at 1270 C. We used isotope labeling of the different carbon sources to prove that the source of the inner tubes is indeed the solvent. Our r...

The basic AB problem is to determine how an unshielded tube of magnetic flux Φ affects arbitrarily long-wavelength charged particles impinging on it. For spin-1 at almost all Φ the particles do not penetrate the tube, so the interaction essentially is periodic in Φ (AB effect). Below-threshold bound states move freely only along the tube axis, and consequent induced vacuum currents supplement r...

FrOR direct measurement of small amounts of power, or for measurement of power over a wide range of frequencies, dynamometer wattmeters are unsatisfactory, and vacuum tube wattmeters are often resorted to. Hitherto vacuum tube wattmeters have depended for their operation on the use of tubes having a square-law characteristic, connected in a push-pull circuit so as to avoid indications caused by...

While vacuum tubes have been almost completely replaced by solid state electronic devices, there are still a few applications where vacuum tubes are used. One of these is in guitar amplifiers. As there are few companies still producing new vacuum tubes, most of the tubes used in amplifiers are old. The electric guitar was invented in the early twentieth century after the advent of the vacuum tu...

BACKGROUND In vitro hemolysis can be induced by several biological and technical sources, and may be worsened by forced aspiration of blood in vacuum tubes. This study was aimed to compare the probability of hemolysis by drawing blood with a commercial evacuated blood collection tube, and S-Monovette used either in the "vacuum" or "aspiration" mode. MATERIALS AND METHODS The study population ...

Two modifications of Malmstrom's cup were used in a study of the position of the cup in 500 vacuum extractor deliveries. The incidence of completely flexing applications varied from 0 to 92 per cent according to the level of the head and the position of the occiput when the cup was applied and, in occipito-posterior positions, the type of cup that was used. With mid-cavity occipito-posterior po...

This audio quality measurement Application Note is geared towards describing the methods for measurement of key audio specifications. Each analysis technique described here in, can be applied to audio ADCs, DACs, Analog Mixers, or any signal within the audio band. Audio quality is typically gauged by three main components. They are Signal to Noise Ratio, Total Harmonic Distortion, and Frequency...

The increased interest in vacuum tube audio amplifiers led to an increased interest in mathematical modelling of such kind of amplifiers. The main purpose of this paper is to develop a novel global numerical approach in calculation of the harmonic distortion (HD) and intermodulation distortion (IM) of vacuum-triode audio amplifiers, suitable for applications using brute-force of modern computer...

An image ultraviolet, visible light, or near infrared is projected onto the transparent window of the vacuum tube as shown in Fig. 1. The vacuum side of this window carries a sensitive layer called the photocathode. Light radiation causes the emission of electrons from the photocathode into the vacuum which are then accelerated by an applied DC voltage towards a luminescent screen (phosphor scr...