Plastics properties developments

The problem of flow through fittings and annular spaces has dealt only with the laminar region the work on annuli was further restricted to the relatively unimportant case of Bingham-plastic behavior. The annular studies to date were quite well chosen in the sense that assumption of Bingham-plastic properties has led to a well-developed method of attack which may not have been possible if more complex non-Newtonian... 

ERL Polar PE. An American plastic explosive developed by the Explosives Research Laboratory, Bruceton, Pa. It consisted of RDX (50-70% thru 30 retained on 200 US Std Sieve and 30-50% thru a 200 US Std Sieve) 88% and Gulf Crown Oil E or Gulf 300 Process Oil [(95%) + Lecithin (5%)1 12%. Its properties resembled the British PE No 2, but possessed improved low temperature behavior... 

T-type calcium channels play critical roles in shaping the electrical and plastic properties of neurons and are also implicated in hormone secretion, differentiation and muscle development (Huguenard, 1996 Perez-Reyes, 2003). In thalamic reticular and relay neurons, T-type channels contribute to rhythmic rebound burst firing and spindle waves associated with slow-wave sleep. T-type channels also play crucial roles in dendritic integration and calcium-mediated spiking in hippocampal pyramidal cells, and in synaptic release at olfactory dendrodendritic... 

Following the successful development of epoxidized soybean oil( 5), mainly as a stabilizer adjuvant with high permanence but poor low temperature plasticizing properties, the epoxidized fatty acid esters were introduced. These included the C8 mono-hydric alcohol esters — octyl epoxystearate and octyl epoxy-tallate. They also acted as stabilizer adjuvants but with outstanding low temperature plasticizing properties. The epoxy stabilizer/plasticizers have grown to over 50,000 tons/year in the U.S. in 1978, with the epoxidized soybean oil type predominating. 

The profound impact of plastic products to people worldwide and in all industries worldwide includes the intelligent application of processing these plastics. These plastics utilize the versatility and vast array of inherent plastic properties as well as the usual high-speed/relative low-energy processing techniques. The result has been the development of millions of cost-effective products used worldwide that in turn continue to have exceptional benefits for people and industries worldwide. 

It may also be possible to eventually extend this bonding concept to the preparation of flakeboards and other wood-base composite materials. If plastics like polystyrene are incorporated into the composite matrix, and successful bonding between the wood and plastic is developed through the graft polymers, the three-dimensional network of plastic material throughout the composite matrix may lead to enhanced physical and mechanical properties as well as improvements in dimensional stability (Figure 2). 

Shear controlled orientation technology was developed to optimize plastic properties by orientation of filler particles. In this patented technology, the single feed is split into a plurality of feeds which can supply pressure to the mold cavity independent of the feed channel. Figure 7.3 shows feed arrangements. The shear is applied by a controlled movement of pistons which imposes microscopic shear. A perfect alignment of fibers can be obtained. 

Hauser et al. [1993] claim that articles for medical and other uses made from a polymer alloy of a clear styrenic acrylate, a ductile styrene-diene polymer, and a rubbery block styrene-diene copolymer may be sterihzed by gamma irradiation, without significant increase in its yellowness index or significant deterioration of the alloy s mechanical properties (Table 11.9). There are many applications, e.g., urine sample botdes, items in space probes, and cosmetic containers, that are made from transparent plastics and need to be radiation-sterihzed. However, many clear plastics do develop color on irradiation, and their mechanical properties tend to deteriorate, particularly on irradiation in air. Hauser et al. 

The major problem in the reprocessing of commingled plastics, and therefore of utmost importance for PAB s, is the immiscibility of most polymers so that poor mechanical properties develop when they are blended together. Ways to enhance the mechanical behavior of these mixtures include adding a compatibilizer, adding a mbbery phase to impact modify the blend, or adding a reinforcement to restore mechanical properties. 

As the drill bit penetrates, microfissuring occurs, plasticity processes develop, and the intrinsic properties of the shale change. 

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