[en] The output pressure of a plunger pump is studied experimentally as a function of the productivity. The corresponding empirical formula is derived.

[en] In the gas main are placed 2 series of specific gas purifiers in parallel. Pressure is controlled with a buffer tank two three way solenoid value upstream and down stream a compressor and a supercharger. A checking board allows continuous monitoring of circuit tightness

[en] One of the most inventive, sustainable strategies used in engineering field is to improve the quality of material and minimize production cost of material for example in this paper is HDPE material. This is because HDPE is an oil base material. This paper proposes to improve its hydrostatic pressure performance for HDPE pipe. The burst test is the most direct measurement of a pipe materials resistance to hydrostatic pressure. Test will be conducted in accordance with ASTM standard for HDPE pipe that undergo electron beam irradiation cross-linking. Studies show the effect of electron beam irradiation will improve the mechanical properties of HDPE pipe. When cross-linking is induced, the mechanical properties such as tensile strength and young modulus is increase correspond to the radiation dose. This happen because the structure of HDPE, which is thermoplastic change to thermosetting. This will indicate the variability of irradiation dose which regard to the pipe pressure rating. Hence, the thickness ratio of pipe will be re-examining in order to make the production of HDPE pipe become more economical. This research review the effects of electron beam on HDPE pipe, as well as to reduce the cost of its production to improve key properties of selected plastic pipe products. (author)

[en] Effective ventilation and positive or low negative pressure indoors are suggested to achieve low indoor radon levels. The aim of this study was to develop and to test equipment which makes it possible to achieve simultaneously effective ventilation and minimum indoor-outdoor pressure difference. The unit included mechanical supply and exhaust air fans, a heat-exchanger and a pressure control unit in direct digital control (DDC), which continuously adjusted air flows based on the pressure difference transmitter information. Indoor radon level decreased from 501 ± 95 Bq/m³ to 202 ± 54 Bq/m³ after two weeks of the equipment's installation during winter conditions. The arithmetic week average of indoor radon level was 135 Bq/m³ from May to August. When the set value of pressure difference adjustment was slightly positive (0.2 Pa) and in-out temperature difference was small in August, the minimum level (38 ± 28 Bq/m³) was obtained. (author)

[en] The Temperature Buffer Test, TBT, is a heated full-scale field experiment presently carried out jointly by Andra and SKB at the Asp6 Hard Rock Laboratory in Southeast Sweden. An existing 8 m deep, 1.8 m diameter KBS3-type deposition hole located at -420 m level has been selected for the test. The objectives are to improve general understanding of Thermo-Hydro-Mechanical behaviour of buffer materials submitted to severe thermal conditions with temperatures well over 100 C during water uptake of partly saturated bentonite-based buffer materials, and to check, in due time, their properties after water saturation. The test includes two carbon steel heating canisters each 3 m high and 0.6 m in diameter, surrounded by 0.6 m of buffer material. There is a 0.2 m thick sand shield between the upper heater and the surrounding bentonite, while the lower heater is surrounded by bentonite only. On top of the stack of bentonite blocks a confining plug is anchored to the rock. In the slot between buffer and rock there is a sand filter equipped with pipes to control water pressure at the boundary, which is seldom done with an EBS in-situ experiment. Both heater mid-height planes are densely instrumented in order to follow, with direct or indirect methods, buffer THM evolution. Temperature, stress, relative humidity, pore pressure have been monitored since the test start in March 2003. Total water inflow is also monitored. At first, the present paper describes the test design, the instrumentation, the plug anchoring system an d the system for water boundary pressure control. Second, having described the test, the paper shows different measurements that illustrate evolution of temperature, saturation, suction and swelling pressure in the upper and the lower buffer. (authors)

[en] Thermostatic expansion valves (TXVs) have long been used in air-cooled chillers to implement head pressure control under which the condensing temperature is kept high at around 50 ^oC by staging condenser fans as few as possible. This paper considers how TXVs prevent the chillers from operating with an increased COP at lower condensing temperatures when the chiller load or outdoor temperature drops. An analysis on an existing air-cooled reciprocating chiller showed that the range of differential pressures across TXVs restricts the maximum heat rejection airflow required to increase the chiller COP, though the set point of condensing temperature is reduced to 22 ^oC from a high level of 45 ^oC. It is possible to use electronic expansion valves to meet the differential pressure requirements for maximum chiller COP. There is a maximum of 28.7% increase in the chiller COP when the heat rejection airflow is able to be maximized in various operating conditions. The results of this paper emphasize criteria for lowering the condensing temperature to enhance the performance of air-cooled chillers

[en] During the LHC run 2011, a tremendous progress has been made towards the machine operation with design parameters. In the same time, the run confirmed the sensitivity of the beam vacuum system to the machine parameters. As expected, a successful scrubbing period allowed mitigating the effects of the electron cloud giving room to an entire filling of the ring with 50 ns beams. In parallel issues such as the impact of the beam screen regulation, pressures spikes and local outgassing were observed during the year. On-line mitigations and immediate compensatory measures implemented during the winter technical stop are reviewed together with their efficiencies. All unexpected pressure behaviours observed during 2011 are understood. The expected limitations while waiting for LS1 consolidation or when running with 25 ns beams are addressed. Lessons for 2012 are discussed. (authors)

[en] Computer simulations of inhomogeneous soft matter systems often require accurate methods for computing the local pressure. We present a simple derivation, based on the virial relation, of two equivalent expressions for the local (atomistic) pressure in a molecular dynamics simulation. One of these expressions, previously derived by other authors via a different route, involves summation over interactions between particles within the region of interest; the other involves summation over interactions across the boundary of the region of interest. We illustrate our derivation using simulations of a simple osmotic system; both expressions produce accurate results even when the region of interest over which the pressure is measured is very small. (paper)

[en] The Hydride Storage Vessel (HSV) in Materials Test Facility (MTF) has been monitored during FY00, and its overpressure has been sampled and analyzed. This report summarizes the findings

[en] Twenty-one patients with high-grade gliomas were enrolled in a prospective trial of radiotherapy after hyperbaric oxygenation (HBO). Radiotherapy was administered in daily 2-Gy fractions up to a total dose of 60 Gy, and each fraction was delivered immediately after HBO. The current study indicated that radiotherapy immediately after HBO with chemotherapy was feasible for high-grade gliomas