Polyethylene tubing

A squeeze bottle can be simply made from a 500-ml. narrowmouthed polyethylene bottle and polyethylene tubing. Holes in the bottle cap and shoulder are made with a sharp cork borer of the appropriate size to ensure a tight fit with the inserted tubing. 

The concrete block walls of the cell housing the generator tube and associated components are 1.7 meters thick. The facility also includes a Kaman Nuclear dual-axis rotator assembly for simultaneous transfer and irradiation of reference and unknown sample, and a dual Na iodide (Nal) scintillation detector system designed for simultaneous counting of activated samples. Automatic transfer of samples between load station to the rotator assembly in front of the target, and back to the count station, is accomplished pneumatically by means of two 1.2cm (i.d.) polyethylene tubes which loop down at both ends of the system and pass underneath the concrete shielding thru a pipe duct. Total one-way traverse distance for the samples is approx 9 meters. In performing quantitative analysis for a particular element by neutron activation, the usual approach is to compare the count rates of an unknown sample with that of a reference standard of known compn irradiated under identical conditions... 

Adventitious surfactants also have a marked effect on the mechanism of coalescence. In studying the coalescence of curved water surfaces, Lindblad (L8) used aged distilled water that was stored for about 30 h in a polyethylene bottle opened to the air through a narrow polyethylene tube inserted in the water. He found that if fresh distilled water (water exposed not longer than 1 h to the air) was used, the delay time in coalescence was approximately half as long. Consequently, he concluded that this difference is due to some form of contamination which settled into the water or onto the water surface. 

A field trial during the winter of 1981-1982 employed a fully automated enclosed design. It utilized fans to deliver cold outside air onto the water surface. The air is conducted to the water surface within polyethylene tubes sewn from sheeting. The outside temperature controls the frequency of water spraying. 

A 5-1. three-necked flask is fitted with a stirrer (which may be of the glass-sleeve type lubricated with paraffin oil, or a mercury-sealed Hirshberg stirrer), an efficient condenser fitted with a calcium chloride drying tube, and a gas inlet tube. The gas inlet tube is connected with polyethylene tubing through a small bubble counter containing a nonvolatile hydrocarbon to the cylinder of boron trichloride. 

In neutron activation analysis, the sample in a suitable container, often a pure polyethylene tube, is bombarded with slow neutrons for a fixed time together with standards. Transmutations convert analyte elements into radioactive elements, which are either different elements or isotopes of the original analyte. 

Silica or copper gives much better heat transfer than do plastic tubes. The checkers found, however, that the use of a condenser was superfluous and that substitution of a simple polyethylene tube long enough to vent the off-gas away from the operator and apparatus was quite satisfactory. 

NOTES Figures in parentheses are flowrates In ml min- Denotes 0.034 in ID polyethylene tubing. 

Fig. 16.1 Equipment for solvent-assisted flavour evaporation. 1 addition funnel, 2 cooling trap, 3 central head with thermostated water jacket, 4 distillation flask, 5 flask cooled with liquid nitrogen for distillate, 6, 7 legs connected to funnel 1 and cooling trap 2, 8 water inlet, 9 connection to the pump system. To ensure constant temperature during distillation, head 3 and legs 6 and 7 are connected by flexible polyethylene tubes that guide the water flask. [15]...

FIGURE 8.9 The process of producing heat-shrinkable polyethylene tubing and the use of the tubing to cover a wire joint Two-sided irradiation of a wire by electron beam. (Singh, A. and Silverman, 1, Eds., Radiation Processing of Polymers, Hanser, Munich, 1992. With permission.)... 

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