Positive pressure

A homogenize is a high pressure positive pump with three, five, or seven pistons, that is driven by a motor and equipped with an adjustable homogenizing valve. Smoother flow and greater capacity are obtained with more pistons, which force the product iato a chamber that feeds the valve. In design and operation, it is desirable to minimize the power requirements for obtaining an acceptable level of homogenization. At 17.2 MPa (2500 psi) and a volume of 0.91 t/h (2000 lb/h), a 56-kW (75-hp) motor is required. 

There are problems to be considered and avoided when using Hquid-in-glass thermometers. One type of these is pressure errors. The change in height of the mercury column is a function of the volume of the bulb compared to the volume of the capillary. An external pressure (positive or negative) which tends to alter the bulb volume causes an error of indication, which may be small for normal barometric pressure variations but large when, for example, using the thermometer in an autoclave or pressure vessel. 

Design flexible connections and their attachment methods to accommodate expected process pressures (positive and negative), system movements and vibrations... 

Matter may also have other forms of energy, potential or kinetic, depending on pressure, position and movement. Enthalpy is the sum of its internal energy and flow work and is given by ... 

Negative duct pressure Positive duct pressure... 

The most common control functions in these early appliances are the control of temperature, pressure, position or distance. Mechanical sensing devices were introduced for these purposes, such as bimetal temperature switches or liquid expansion temperature switches for ovens, washing machines, dishwashers, refrigerators, etc. Electromechanical pressure switches and potentiometric level sensors have also been introduced quite early. 

The pressure acting on a surface in a static fluid is the normal force per unit area, ie the normal stress. The pressure of the surrounding fluid acts inwards on each face of a fluid element. Consequently, with the negative sign convention the normal stress components may be identified with the pressure. With the positive sign convention, the normal stress components may be identified with the negative of the pressure positive normal stresses correspond to tension with this convention. 

Maintain higher air pressures (positive pressure) within the critical areas to minimize infiltration of airborne contaminants from outside air... 

Tip 2 View laughter as therapeutic. Just as negative emotions can produce ulcers, headaches, and high blood pressure, positive emotions such as laughter can relax nerves, improve digestion, and help blood circulation. 

Hultman et al. [130] developed a LC/MS/MS method for the quantitative determination of esomeprazole and its two main metabolites 5-hydro-xyesomeprazole and omeprazole sulfone in 25 /il human, rat, or dog plasma. The analytes and their internal standards were extracted from plasma into methyl ferf-butyl ether-dichloromethane (3 2). After evaporation and reconstitution of the organic extract, the analytes were separated on a reversed-phase liquid chromatography column and measured by atmospheric-pressure positive ionization mass spectrometry. 

If operation above design flux is required for short periods of time, pressurized systems are preferred, as they operate under a positive trans-membrane pressure positive pressure can always be increased, while vaccum is limited. 

As a point of reference, typical healthy human lungs can develop 50 or more inches (12.5 kPa gauge) of water pressure. Compare the pressure that lungs can supply to the typical 10-inch (2.5 kPa gauge) water pressure positive design pressure of low-pressure... 

Depending on the designed maximum product pressure of the downstream scraped-surface heat exchanger and the various types of margarine produced, high-pressure positive-displacement pumps with maximum discharge pressures of 40 bars (about 600 psi), 70 bars (about 1030 psi), or 120 bars (about ISOOpsi) are normally installed in the process hne. 

In the feed section, the mainly l--hexene reactant (98.60% 1-hexene, 0.95% cis-3 hexene, 0.25% trans-2 hexene and 0.15% cis-2 hexene, supplied by Ethyl corporation) is introduced from an Instrumentation Specialties Company (ISCO) model 314 metering pump into a flowing stream of liquefied COo. The l-hexene/C02 mixture is then fed to a high pressure positive displacement pump contained in the SCESS. In this pump, fluids can be pressurized up to 6,000 psig and total flow rate can be adjusted between 46 ml/hr and 460 ml/hr. Since feed to the pump must be in a liquid state, both the l-hexene/C02 mixture and the pump head are sufficiently cooled by circulating chilled water at 5 C. The system pressure is controlled by means of an adjustable back pressure regulator. 

Negative heats of solution form stronger bonds and lower vapor pressure positive heats of solution form weaker bonds and raise vapor pressure. 

Acrylate grout pumping units shall consist of two, parallel high pressure, positive displacement pumps with parallel hoses leading to a mixing chamber or Y at the packer. Pumps shall be equipped with check valves to prevent the back-flow of one grout component into the lines of the other component. 

Normal expiration is a passive process, and when the inspiratory muscles end their contraction, the elastic recoil of the lung pulls the lung back to its original size and shape. This process makes the alveolar pressure positive relative to the pressure at the mouth, and air flows out of the lung. During inspiration, the respiratory muscles must overcome the elastic properties of the lung (elastic recoil) and the resistance to airflow by the airways. During expiration, the flow of air is determined primarily by the elastic recoil and airway resistance. 

PEEP Positive end-expiratory pressure positive pressure at the end of exhalation designed to prevent alveoli from collapsing during expiration. 

In this paper, the results of mass spectrometric investigations on low pressure positive corona discharges established between two coaxially placed electrodes will be discussed. This form of discharge has been chosen primarily because its electrical properties are relatively simple and better understood. Further, the ion-sheath effects at the point of sampling are minimized because of the low level of ionization in these systems. 

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