Dilatational characteristics

Soft solids, most of which are biological waste such as sewage, are difficult to convey up the beach. Annular baffles or dams have been commonly used to provide a pool-level difference wherein the pool is deeper upstream of the baffle toward the clarifier and lower downstream of the baffle toward the beach. The pool-level difference across the baffle, together with the differential speed, provide the driving force to convey the compressible sludge up the beach. This has been used effectively in thickening of waste-activated sludge and in some cases of fine clay with dilatant characteristics. 

Dilatational Characteristics of Protein-LMWE Mixed Films.267... 

Surface dilatational rheology is a very sensitive technique to analyze the competitive adsorption/displacement of protein and LMWE emulsifier at the air-water interface (Patino et al., 2003). A common trend is that the surface dilatational modulus increases as the monolayer is compressed and is a maximum at the highest surface pressures, at the collapse point of the mixed film, and as the content of LMWE in the mixture increases. At higher TT, the collapsed protein residues displaced from the interface by LMWE molecules have important influence on the dilatational characteristics of the mixed films. The mechanical properties of the mixed films also demonstrate that, even at the highest tt, the LMWE is unable to displace completely protein molecules from the air-water interface. 

In 2009, Rawlings, Inc. introduced a football helmet with a TPU cushioning system that comprised pressured gas chambers (Rawlings, 2014a). The pneumatic liner system included a network of interconnected chambers containing a spacer fabric composed of poly(hexamethylene adipamide), commonly known as nylon, to maintain the pad design. The comfort liner included a new urethane foam material that is engineered to respond with dilatant characteristics upon impact. The newly available Tachyon helmet contains individual gas chambers placed within multiimpact foam. 

The only small-scale methods that have stood the test of time and have been accepted as standard plasticity tests are the crucible swelling number, Gray-King coke type, dilatation characteristics, Gieseler plasticity, and, in some countries, the Rogas index. All of these are essentially empirical in nature and many are subjective, at least to some degree. 

Table I. shows the calculated results of dilate limit. It is obvious that the nea.rest-neighlror interactions are of major importance. The fundamental characteristic features of ordering systems such as PdV, NiV, and NiAl are explained by the large positive value of the NN IE s positive means repulsion between the two impurity atoms. The continuous solid solubilities of CuNi a.nd AgPd correspond to the small values of the IE s. ...

Dilatant Basically a material with the ability to increase the volume when its shape is changed. A rheological flow characteristic evidenced by an increase in viscosity with increasing rate of shear. The dilatant fluid, or inverted pseudoplastic, is one whose apparent viscosity increases simultaneously with increasing rate of shear for example, the act of stirring creates instantly an increase in resistance to stirring. 

The concepts of interface rheology are derived from the rheology of three-dimensional phases. Characteristic for the interface rheology is the coupling of the motions of an interface with the flow processes in the bulk close to the interface. Thus, in interface rheology the shear and dilatational stresses of the interface are in equilibrium with the corresponding shear stress in the bulk. An important feature is the compressibility of the adsorption layer of an interface in contrast, the flow elements of the bulk are incompressible. As a result, compression or dilatation of the adsorption layer of a soluble surfactant is associated with desorption and adsorption processes by which the interface tends to reinstate the adsorption equilibrium with the bulk phase. 

Ed is the dilatational elasticity, and rid is the dilatational viscosity. It is characteristic for a stable foam to exhibit a high surface dilatational elasticity and a high dilatational viscosity. Therefore effective defoamers should reduce these properties of the foam. 

The shape of the curves for the dilational modulus (Figures 7 and 8) suggests a single relaxation mechanism, probably the unfolding of the demulsifier molecules at the interface. The frequency peak in the e"(f) plot is a measure of the characteristic relaxation time. A shorter relaxation time, by inducing faster film drainage, increases demulsification efficiency. 

Renal Effects. The characteristics of early or acute lead-induced nephropathy in humans include nuclear inclusion bodies, mitochondrial changes, and cytomegaly of the proximal tubular epithelial cells dysfunction of the proximal tubules (Fanconi s syndrome) manifested as aminoaciduria, glucosuria, and phosphaturia with hypophosphatemia and increased sodium and decreased uric acid excretion. These effects appear to be reversible. Characteristics of chronic lead nephropathy include progressive interstitial fibrosis, dilation of tubules and atrophy or hyperplasia of the tubular epithelial cells, and few or no nuclear inclusion bodies, reduction in glomerular filtration rate, and azotemia. These effects are irreversible. The acute form is reported in lead-intoxicated children, whose primary exposure is via the oral route, and sometimes in lead workers. The chronic form is reported mainly in lead workers, whose primary exposure is via inhalation. Animal studies provide evidence of nephropathy similar to that which occurs in humans, particularly the acute form (see Section 2.2.3.2). 

Muscle tremors and convulsions are characteristic effects of acute dermal phenol toxicity in laboratory animals. Tremors that developed into convulsions and prostration were reported in rats exposed to 107.1 mg/kg liquid phenol application surface areas were not reported (Conning and Hayes 1970). In pigs, application of 500 mg/kg over 35-40% of the body surface (0.44 mg/cm2/kg) resulted in muscular tremors in the head region within 3-5 minutes of exposure (Pullin et al. 1978). This was followed by dilation of the pupils, loss of coordination, and excess salivation and nasal discharge within 5 minutes of exposure. It was followed by convulsions, coma, and death 5-7 minutes after exposure in two of three pigs. Direct application of a dose of 37.5 mg/kg phenol to the inner ear resulted in a reduced threshold for auditory brainstem response (Schmidt et al. 1990). 

A characteristic TNT cataract is reportedly produced with exposures regularly exceeding l.Omg/m for more than 5 years. In one study, 6 of 12 workers had bilateral peripheral cataracts, visible only with maximum dilation. The opacities did not interfere with visual acuity or visual fields. The induced cataracts may not regress once exposure ceases, although progression is arrested. 

Ibopamine (2% eye drop) is recently introduced newer compound, producing dose dependent mydriasis endowed with very interesting characteristics rapid onset, marked pupil dilatation and rapid return to normal pupillary diameter. This rapid return to normal pupillary diameter after its diagnostic application in eye offers significant advantages compared to other currently available mydriatics. Ibopamine is well absorbed through the cornea, it is rapidly hydrolyzed by esterases to epinine and the mydriatic effect is correlated with the concentration of epinine in the aqueous humor. 

Intradermal injection of histamine causes a characteristic red spot, edema, and flare response that was first described many years ago. The effect involves three separate cell types smooth muscle in the microcirculation, capillary or venular endothelium, and sensory nerve endings. At the site of injection, a reddening appears owing to dilation of small vessels, followed soon by an edematous wheal at the injection site and a red irregular flare surrounding the wheal. The flare is said to be caused by an axon reflex. A sensation of itching may accompany these effects. 

Prostaglandins have been implicated both in the induction of inflammation and in its relief. In inflammation small blood vessels become dilated, and fluid and proteins leak into the interstitial spaces to produce the characteristic swelling (edema). Many polymorphonuclear leukocytes attracted by chemotactic factors that include LTB4309 (Chapter 19) migrate into the inflamed area, engulfing dead tissue and bacteria. In this process lysosomes of the leukocytes release phospholipase A, which hydrolyzes phospholipids and initiates the arachidonate cascade. The leukotrienes that are formed promote the inflammatory response. However, cAMP can suppress inflammation, and PGE2 has a similar effect. Indeed, E prostaglandins, when inhaled in small amounts, relieve asthma. 

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