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[en] Gaseous UF6 is withdrawn from a first system and directed into a second system for converting the gas to liquid UF6 at an elevated temperature. An improved method for withdrawing the liquid UF6 from the second system and storing it as a solid in a plurality of storage vessel is claimed. The method comprises the steps of: (a) directing an increment of liquid UF6 from the second system into a first closed storage vessel; (b) flash-evaporating UF6 from the first vessel into one of the first system and second system to cool and solidify UF6 in the first vessel while directing an increment of liquid UF6 from the second system into a second closed storage vessel; (c) flash-evaporating UF6 from the second vessel into one of the first system and second system to cool and solidify UF6 in the second vessel while directing another increment of liquid UF6 from the second system into the first vessel; and (d) flash-evaporating UF6 from the first vessel into one of the first system and second system to cool and solidify additional UF6 in the first vessel
[en] A cooling tower is described where water runs over packing plates being cooled by steaming air. In the cooling process a combination of wet and dry cooling is applied, namely by special design of the packing plates which are arranged inclined to the vertical. Spraying device and packing plates are shaped in such a way that the plates are wetted almost on one side only. 13 drawings explain the construction of the device described in detail. (UWI)
[de]Es wird ein Kuehlturm beschrieben, bei dem Wasser ueber Rieselplatten laeuft und durch stroemende Luft abgekuehlt wird. Beim Kuehlverfahren wird eine Kombination Nass-Trockenkuehlung angewandt, und zwar durch besondere Ausgestaltung der Rieselplatten, die zur Vertikalen geneigt angeordnet sind. Spruehvorrichtung und Rieselplatten sind so ausgebildet, dass die Rieselplatten fast nur einseitig benetzt werden. 13 Zeichungen verdeutlichen den ausfuehrlich beschriebenen Aufbau der Vorrichtung. (UWI)
[en] An economizer is disclosed having a plurality of stages for flash cooling refrigerant liquid for use in a refrigeration system. The refrigerant liquid is cooled by evaporation of a portion of the liquid as it passes through throttling means into chambers of successively lower pressure. Sump means are provided to collect the refrigerant liquid flowing between the chambers. As the refrigerant enters each chamber, it is deflected by distribution means, thereby effecting more efficient separation of the flashed refrigerant vapor from the resulting liquid spray
[en] Presently, a trapping system for cooling highly-charged ions (HCI) is being set up at AlbaNova at Stockholm University. The experiment aims at production of low temperature (emittance) HCI at very low energy. HCI are extracted from the new Stockholm EBIT (S-EBIT) before evaporative cooling is applied in a Penning trap. In the future the cooled ions will be injected into the precision trap of the high-precision mass spectrometer SMILETRAP II. In first tests the emittance of trapped ions was measured and it was shown that highly and low-charged ions could be simultaneously stored.
[en] Cooling by evaporation from an isolated aggregate can be quite rapid. The possibility of bypassing phase transitions and thus of preparing interesting amorphous materials by this vector must then be considered. Evaporation from binary solutions is identified as an especially attractive mechanism for realizing this prospect
[en] Beam stopping elements using the hypervapotron cooling technique have been tested by JET to evaluate their peak power and total power handling capacities. The results of this evaluation are presented in this paper
[en] We report on the realization of a sodium Bose-Einstein condensate (BEC) in a combined red-detuned optical dipole trap formed by two beams crossing in a horizontal plane and a third, tightly focused dimple trap (dT) propagating vertically. We produce a BEC in three main steps: loading of the crossed dipole trap from laser-cooled atoms, an intermediate evaporative cooling stage that results in efficient loading of the auxiliary dT, and a final evaporative cooling stage in the dT. Our protocol is implemented in a compact setup and allows us to reach quantum degeneracy even with relatively modest initial atom numbers and available laser power.
[en] The Merkel coefficient, or evaporation coefficient, is still being used as a characteristic factor for the cooling tower process. Its dependence on the cooling range or on the warm water temperature of the process is often considered a disadvantage of the theory of evaporation cooling. This is also the reason for the suggestion to change the theory in such a way that the Merkel coefficient becomes independent of the temperature. The present investigation, however, leads to the result that the dependence of the Merkel coefficient on the temperature must be considered as a remarkable confirmation for the evidence of the theory of heat and mass transfer, as the experimental statements agree fully with the results of the theoretical considerations. (orig.)
[de]Als charakteristische Kennzahl fuer den Kuehlturmprozess wird weithin die Merkel-Zahl oder Verdunstungskennzahl benutzt. Ihre Abhaengigkeit von der Kuehlzonenbreite oder von der Warmwassertemperatur des Prozesses wird haeufig als Mangel der Theorie der Verdunstungskuehlung angesehen. Darauf ist auch der Vorschlag zurueckzufuehren, die Theorie so abzuwandeln, dass die Merkel-Zahlen unabhaengig von der Temperatur werden. Die hier vorgenommene Untersuchung fuehrt dagegen zu dem Ergebnis, dass die Temperaturabhaengigkeit der Merkel-Zahl als bemerkenswerte Bestaetigung fuer die Aussagen der Theorie der Waerme- und Stoffuebertragung angesehen werden muss, weil die experimentellen Befunde vollauf mit dem Resultat der theoretischen Ueberlegungen uebereinstimmen. (orig.)
[en] As atoms get colder, they start to behave more like waves and less like particles. Cool a cloud of identical atoms so cold that the wave of each atom starts to overlap with the wave of its neighbor atom, and all of a sudden you wind up with a sort of quantum identity crisis known as Bose-Einstein condensation. How does one get something that cold? And what is the nature of the strange goop that results? These questions were addressed in a colloquium at the National Institute of Standards and Technology in Gaithersburg, Maryland, on February 23, 1996. This paper is an edited transcript of that presentation
[en] Effects of evaporative cooling system on productive performances and reproductive performances of crossbred Holstein Friesian cattle in tropical condition were studied. Twenty primiparous 87.5% crossbred Friesian cattle were used in the experiment. They were divided into two groups of ten animals each. One group was kept in evaporative cooling system (EVAP) that temperature reduced by using air force movement through cooling pad. Another group was kept in the open conventional housing system (NEVAP). Temperature-humidity index (THI) was daily calculated according to NOAA and used to differentiate the severity of heat stress in each housing system. Productive performances and reproductive performances were measured starting from parturition until 10 weeks of lactation Productive performances of experimental animals were shown. Maximum temperature in EVAP and NEVAP during the study was 29.1, 35.8 deg C and minimum temperature was 22.2 and 23.6 deg C respectively. Average THI in EVAP and NEVAP was 77 and 81 respectively. DMI and DMI % BW of cows in EVAP were significant higher (P < 0.05) than cows in NEVAP. Animals in EVAP consumed 19.8% more feed than animals in NEVAP. Cows in EVAP produced significantly more milk than cows in NEVAP (P < 0.01). Milk yield of cows in EVAP and NEVAP were 16.9 kg/d and 12.6 kg/d respectively. 4% FCM production of cows in EVAP was significantly higher (P < 0.01). Cows in EVAP could produce 3.5 kg of 4% FCM more than cows in NEVAP. DMI/4%FCM of cows in EVAP and NEVAP were 0.70 and 0.77 respectively in, which no difference was found. It was found that animals in EVAP consumed 54.4 L of water per day compare to 93.6 L in NEVAP, which was highly significant difference (P < 0.01). When water intake per DMI was compared, less water intake was found in EVAP (P < 0.01). Cows in NEVAP consume 6.1 L of water/kg DMI more than cows in EVAP. Data of milk compositions were shown. No significant differences in milk composition between EVAP and NEVAP were found. No difference was found in eating time and ruminating time. However, cows in EVAP spent more time (P < 0.05) for total chewing time than cows in NEVAP. The concentrations of individual volatile fatty acids (acetate, propionate and butyrate) from both groups of animals were similar. The total concentration of volatile fatty acids and the ratio of acetate to propionate in cows were slightly higher in EVAP but no significant difference was found. Reproductive performances of cows in EVAP and NEVAP were shown. No difference was found in all parameters measured, though better performances were shown in animals kept in NEVAP. (author)