Search of Noise Source of Spiral Vacuum Pump

Emergency power source for an ion vacuum pump.

This note describes a simple high-voltage dc generator which serves as an emergency power source for an ion vacuum pump during power interruptions, or failure of the main supply.

Vacuum Gauge to Vacuum Pump Valve

Noise reduction of spiral ducts.

The paper presents noise reduction (NR) of spiral ducts as a result of computational modeling of acoustic wave propagation. Three-dimensional models were created with the finite element method in COMSOL Multiphysics version 3.3. Nine models of spiral ducts with 1-9 spiral leads were considered. Time-harmonic analysis was used to predict NR, which was shown in spectral and interval frequency ban...

Noise-induced Brownian motion of spiral waves.

We study the erratic displacement of spiral waves forced to move in a medium with random spatiotemporal excitability. Analytical work and numerical simulations are performed in relation to a kinematic scheme, assumed to describe the autowave dynamics for weakly excitable systems. Under such an approach, the Brownian character of this motion is proved and the corresponding dispersion coefficient...

Assessment and Deployment of Ground Source Heat Pump for Air Pollution Reduction in Tehran, Iran

The use of renewable energies, especially in metropolises has led to a reduction in environmental pollution and greater access to clean, renewable and sustainable energy. This paper evaluates the effectiveness of a national plan adopted by the Tehran city council for reducing air pollutions. This plan is designed to increase the share of renewable energies in residential buildings. This study a...