High stalk

Because of its low melting point and high chemical stability, HDPE is easily processed by most conventional techniques (injection molding, blow molding, rotational molding, and extrusion). Blown HDPE film is manufactured orr high stalk film lines specialized techniques have also been described. 

An unusual feature of fabricating HMW-HDPE into film is the length the molten polyethylene travels during the film-forming process before the bubble is inflated. The bubble shape is illustrated in Figure 6.17 and is referred to as high-stalk extrusion. This extrusion shape is used in order to produce film with more balanced orientation (more balanced properties in the MD and TD direction). After the melt exits the die, the melt is drawn down by about a factor of 20 in the machine direction before the bubble is inflated with a blow-up ratio of 4, i.e., the diameter of the bubble is four times the diameter of the die. Hence, the melt is drawn down by a factor of 80. Consequently, a final film thickness of 0.5 mils is obtained with a die... 

Figure 6.17 Illustration of high-stalk extrusion of HMW-HDPE polyethylene.

MODELING OF NON-ISOTHERMAL HIGH STALK FILM BLOWING PROCESS BY USING VARIATIONAL PRINCIPLES FOR NON-NEWTONIAN FLUIDS... 

Determination of the temperature profile from the measured high stalk bubble shape... 

Effect of molecular weight and long chain branching on the high stalk film blowing process... 

Table 2 Expression for the temperature profile in the first (T1) and second (T2) part of the high stalk bubble.

Figure 1 HDPE high stalk bubble. Mass flow rate 0.038432 kg/hour, 0.06 die gap, 100 mm die radius, 204°C die temperature. Final film thickness equal to 13 oon (vl=1.30048 m/s). TUR=25.6, Ap=69. la) Low cooling rate conditions b) High cooling rate conditions...

Figure 4 Theoretical investigation of the molecular weight (4a) and long chain branching (4b) on the high stalk bubble formation by the help of the Zatloukal-Vlcek film blowing model and generalized Newtonian model.

The posterior lobe of the pituitary, ie, the neurohypophysis, is under direct nervous control (1), unlike most other endocrine organs. The hormones stored in this gland are formed in hypothalamic nerve cells but pass through nerve stalks into the posterior pituitary. As early as 1895 it was found that pituitrin [50-57-7] an extract of the posterior lobe, raises blood pressure when injected (2), and that Pitocin [50-56-6] (Parke-Davis) causes contractions of smooth muscle, especially in the utems (3). Isolation of the active materials involved in these extracts is the result of work from several laboratories. Several highly active posterior pituitary extracts have been discovered (4), and it has been deterrnined that their biological activities result from peptide hormones, ie, low molecular weight substances not covalendy linked to proteins (qv) (5). 

Figure 6.19 Small organisms found inside a tubercle. Each is about 0.05 in. (0.13 cm) high. The organisms have segmented, fibrous stalks and bivariate heads.

The frequency of microwave radiation lies between that of IR radiation and high frequency radio waves and the boundaries between these regions are not fixed [221]. The microwaves are generated in a transmitter (magnetron) which possesses a stalk which penetrates Uke a radio antenna into a hollow energy guide (Fig. 48). This leads the electromagnetic waves into the reaction chamber (power about... 

Summing up these results, it is clear that beating and swelling of cotton stalk pulp have important effects on graftability. At high-monomer concentrations, the graftability is higher in the swollen samples than in the beaten samples. 

Figure 9. Proposed cyclic mechanism for ATP synthesis by complex V involving all three catalytic sites of F,. In this scheme only the a and p subunits of F, are shown these are connected by a short stalk to F, in the inner membrane. Proton translocation through Fq driven by the proton motive force (AP) causes sequential conformational changes in each of the p-subunits and ATP synthesis as described in the text hexagons, high-affinity sites semicircles, low affinity sites parallelepipeds, intermediate-affinity sites (with no movement of F,).

Lamina II is also known as the substantia gelatinosa (SG) and can be divided into two layers, the outer layer (IIo) and the inner layer (Ili). This layer is densely packed with small neurons and lacks myelinated axons. Neurons with cell bodies in Hi receive inputs from low-threshold mechanoreceptive primary afferents, while those in IIo respond to inputs from high-threshold and thermoreceptive afferents. The intrinsic cells which comprise the SG are predominantly stalk and islet cells. Stalk cells are found located in lamina IIo, particularly on the border of lamina I, and most of their axons have ramifications in lamina I although some also project to deeper layers. These cells are thought to predominantly relay excitatory transmission. Islet cells, on the other hand, are located in Hi and have been demonstrated to contain the inhibitory neurotransmitters, y-aminobutyric acid (GABA), glycine and enkephalins in their dendrites. Hence these cells have been proposed to be inhibitory interneurons. 

The flowers are small, about 1/5 of an inch long with five lobed corollas with five stamens and short filaments. The flowers are fragrant and form a flat-topped cluster (known as a corymbose cyme) with stalks of different lengths all growing to the same level. They bloom from the center outward. The flowers are often pollinated by flies and other insects. The purplish black berries, which ripen in September in the Northern Hemisphere, contain ovate greenish brown seeds. The berries are actually black, but have a powdery blush on them which makes them appear blue. There are often three seeds in each berry. Red berries, which should not be eaten, have too high a saponin content which even keeps animals from consuming them. Plants can usually reproduce by the time they are three to five years old. 

The Hg concentration variations within fungal tissues (Fig. 1) also follow a rather complex pattern (Table 3). For example, Cortinarius, Bankera, Cantharelius and Lactarius accumulate more Hg than what can be accounted for by variables such as (1) the systematic stalk versus cap differences, (2) the reductions of the Hg concentrations from the emerging to the over-mature mushroom stage, (3) the C, Hg and S contents in the L, F, H, A layers, (4) the reduction of Hg uptake from soils with high S levels, (5) the increased Hg uptake from soils with high Hg concentrations,tempered by increased C concentrations. 

Going in the opposite direction, i.e. when we consider the membrane stability with increasing ionic strength, we notice the approach of k towards zero. Going towards this value, the tendency of the bilayers to form saddle-shaped connections (also called stalks ) between bilayers increases. Saddle-shaped membrane structures also occur in processes like vesicle fusion, endo and exocytosis. The SCF predictions thus indicate that these events will occur with more ease at high ionic strength than at very low ionic strength. 

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