Screws plastication

Procedure. Weigh 10 g air-dry soil, sieved to 2 mm (10 mesh) using a stainless steel sieve into a 175-ml square HDPE (e.g. Nalgene) plastic screw-cap... 

Prepare Hybridization Mix containing 500 ng/ml of DIG-labeled RNA probe in a plastic screw-cap tube, and transfer the embryos. 

Adding or changing a child-resistant closure, changing from a metal to plastic screw cap, or changing from a plastic to metal screw cap. 

N. S. Rao, Computer Aided Design of Plasticating Screws, Hanser Publishers, Munich, Germany, 1986. 

Prepare neat (solvent-free) trans calibration standards by weighing accurately, on an analytical balance (to the nearest 0.0001 g), 0.3 -x g of a trans-free reference fat and x g of trielaidin (TE) into each of a series of 10-mL beakers, where x equals 0.0015, 0.0030, 0.0150, 0.0300, 0.0600, 0.0900, 0.1200, and 0.1500 g. Store calibration standards in plastic screw-cap vials. 

The dried acid chloride is conveniently stored in about 25 bottles with tightly fitting plastic screw caps which are kept in a desiccator over phosphorus pentoxide. In this manner the acid chloride is exposed to a minimum of atmospheric moisture when reactions arc run which require only part of the preparation. 

Contact of the perfluoroalkanesulfonic acids with cork, mbber, cellulose, and plasticized materials will cause discoloration and deterioration of these materials. Samples are best stored in glass ampoules or glass bottles with Kel-For Teflon plastic screw-cap linings. 

Fig. 34.5. Capillary electrophoretic system with electrochemical detection. (A) Glass microchip, (B) separation channel, (C) injection channel, (D) pipette tip for buffer reservoir, (E) pipette tip for sample reservoir, (F) pipette tip for reservoir not used, (G) Plexiglass body, (H) buffer reservoir, (I) sample reservoir, (J) blocked (unused) reservoir, (K) detection reservoir, (L) screen-printed working-electrode strip, (M) screen-printed working electrode, (N) silver ink contact, (0) insulator, (P) tape (spacer), (Q) channel outlet, (R) counter electrode, (S) reference electrode, (T) high-voltage power electrodes, (U) plastic screw. For clarity, the chip, its holder, and the screen-printed electrode strip are separated, and dimensions are not in scale. Reprinted with permission from Ref. [112]. Copyright (1999) American Chemical Society.

Screw-cap containers of fuming nitric acid may develop pressure on storage, owing to attack on the plastic screw cap if the inert protective cap liner fails. Regular pressure release is recommended by one laboratory supplier. For a discussion of the hazards of mixtures of many organic compounds with HN03, see Andrussow.2... 

Z. Tadmor and I. Klein, Engineering Principles of Plasticating Screw Extrusion, Van Nostrand Reinhold, New York, 1970. 

G. Lidor and Z. Tadmor, Theoretical Analysis of Residence Time Distribution Functions in Plasticating Screw Extruders," Polym. Eng. Sci., 16, 450-462, (1976). 

Fig. 9.12 Experimental verification of the RTD function in extruder by radioactive tracer techniques with a 44.2-mm-diameter, 24 1 L/D extruder, liquid polyester resin, and a radioactive manganese dioxide tracer Asterisk, Experiment 1 , Experiment 2 smooth curve indicates theoretical prediction. [Reprinted by permission from D. Wolf and D. H. White, Experimental Study of the Residence Time Distribution in Plasticating Screw Extruders, AIChE J., 22, 122-131 (1976).]...

Fig. 9.18 Schematic representation of a plasticating screw extruder. The barrel is cooled in the hopper region and heated downstream. Typical plasticating SSE have length-to-diameter ratios of 24—26.

The theoretical analysis of the injection unit involves all the facets of steady, continuous, plasticating screw extrusion, with the added complication of a transient... 

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