Vacuum physics is the necessary condition for scientific research and modern high technology. In this introduction to the physics and technology of vacuum the basic concepts of a gas composed of atoms and molecules are presented. These gas particles are contained in a partially empty volume forming the vacuum. The fundamentals of vacuum, molecular density, pressure, velocity distribution, mean ...

BACKGROUND : Immobilization of the spine in patients with trauma at risk of spinal damage is performed using a rigid long spineboard or vacuum mattress both during prehospital and in-hospital care. However, disadvantages of these immobilization devices in terms of discomfort and tissue-interface pressures have guided the development of a new soft-layered long spineboard. We compared tissue-inte...

With the aim of optimization, numerical simulations of the cooling and vacuum systems of a compact 12 MeV race-track microtron (RTM) which is under construction at the Technical University of Catalonia have been carried out. The hydraulic and thermal performance of the cooling system for various flow rates has been studied using the Computational Fluid Dynamics (CFD) software. A CFD model, prev...

home uterine activity monitoring (huam) has demonstrated to be of great value for preventing preterm labor in recent years. in this research, a low cost monitoring device for non-invasive monitoring of the uterine activity in pregnant women is presented. the new device has been designed based on an inductive colpitz oscillator and vertical displacement of a ferrite core in a coil. the resulting...

A vacuum system with pressure in the low ultra-high vacuum (UHV) range is essential for long photocathode lifetimes in DC high voltage GaAs photoguns. A discrepancy between predicted and measured base pressure in the CEBAF photoguns motivated this study of outgassing rates of three 304 stainless steel chambers with different pretreatments and pump speed measurements of non-evaporable getter (NE...

An ion beam has quite different vacuum requirements in different sections of an accelerator. Behind a stripper gas or after interaction with a gas target the vacuum conditions are poor, whereas in an accelerator module or especially in a storage ring the residual gas pressure has to be orders of magnitude better. As a new device to allow an ion beam to enter sections of different pressure we in...

A simulation program is developed which is capable of calculating the output responses of piezoresistive pressure sensors as a function of pressure and temperature. Analytical models based on small and large deflection theories have been applied to predict the sensitivity and linearity of pressure sensors. Surfacemicromachined diaphragms with square or circular shapes, fabricated by a low press...

The lateral Casimir-Polder force between an atom and a corrugated surface should allow one to study experimentally nontrivial geometrical effects in the electromagnetic quantum vacuum. Here, we derive the theoretical expression of this force in the scattering approach. We show that large corrections to the "proximity force approximation" could be measured using present-day technology with a Bos...

Microwave (MW) vacuum dehydration using temperature to control the level of MW power demonstrated potential in improving the performance of the process. Product surface temperature measured by an infrared temperature sensor was used to control MW power at any level between 0 and 3 kW. Multiple linear regression analysis indicated an r2 = 0.942 for prediction of final moisture content and r2 = 0...

Vacuum force (suction) is commonly used in wound management strategies. Topical negative pressure wound therapy and closed surgical wound drainage both use vacuum force but each have different modus operandi.