Partial draining

The ideal recommended cyanuric acid concentration is 30—50 ppm (Table 2). Although this range can be readily maintained when using hypochlorite sanitizers, it cannot be maintained when using chloroisocyanurates since they increase the cyanuric acid concentration. The NSPI recommends a maximum of 150 ppm cyanuric acid. Many health departments limit cyanuric acid to 100 ppm. No significant increase in stabilization occurs beyond 50—100 ppm, and since high levels of cyanuric acid slow down the rate of disinfection, the pool water should be partially drained and replaced with fresh water to reduce the cyanuric acid to below recommended maximum levels. Cyanuric acid is determined turbidimetricaHy after precipitation as melamine cyanurate. 

The pressure in the vapour space of an incompletely full, sealed vessel containing liquid cannot be reduced by partially draining off liquid. 

Closed-loop systems should lose very little water, perhaps only 5 to 10% of the system volume per year. In practice, however, losses often tend to be much higher than this, perhaps due to unforeseen maintenance work that necessitates a system to be partially drained. A typical loss is more likely to be 50% of the system volume per season. This obviously causes problems with regard to maintaining adequate chemical treatment reserves for effective deposit and corrosion control. In fact, often the first sign that a closed-loop system is losing water is when a periodic test is undertaken and the result indicates a reduced level or complete lack of treatment reserve. 

Three of five men, who lost consciousness within a few minutes of entering a partially drained underground liquid manure storage tank, died before reaching the hospital autopsy showed that two had massive liquid manure pulmonary aspiration, while the third had fulminant pulmonary edema without manure aspiration (Osbem and Crapo 1981). Markedly elevated heart-blood sulfide-ion levels indicated significant hydrogen sulfide exposure. Air samples analyzed about a week after the accident detected only 76 ppm of hydrogen sulfide, but the study authors noted that the environmental conditions were probably different (e g., warmer weather, less-concentrated manure). 

Note A freely draining macromolecule and a non-draining macromolecule are two extremes of the concept of a partially draining macromolecule. 

In the manufacture of Labneh and other Middle Eastern fermented milks, the fermented product is concentrated by removing part of the serum (whey). This was done traditionally by stirring the yoghurt and transferring it to muslin bags to partially drain. Concentration can now be achieved by ultrafiltration, before, but preferably after, fermentation. 

The lamp is mounted securely at its ends and connected to a source of direct current preferably 220 volts or 500 volts through suitable resistances and a switch. The switch is closed and a small Bunsen flame is played on the capillary between A and B. The mercury vaporizes and the arc strikes and is localized between the two bulbs. As soon as the lamp starts, water is turned on so that it flows down around the lamp in a large stream. The cold water keeps the cement intact and preserves the lamp. The energy is so intense that without water-cooling the quartz would be melted immediately. Hard water may be used provided that it passes over the lamp so rapidly that there is not time to heat up the water and deposit lime. The mounting of the lamp may be varied for different purposes. The lamp may be placed in front of a quartz window in a copper tank which is partially drained until the lamp is started. After starting, the tank is allowed to fill to an outlet near the top thus covering the lamp. 

Meyerhoff (182)] but also in the short-chain region [Marzolph and Schulz (176)]. The decrease in the slope of the double-logarithmic plot at low molecular weights is naturally and faithfully reproduced. This would be equally true of the Flory-Fox theory, as represented by Eqs. (5) to (8). There seems to be absolutely no evidence for partial draining of the solvent through the polymer coils, such as would be predicted by the theories of Brinkman (45 ), Debye and Bueche (79), Kirkwood and... 

Fig. 12. Viscosity-molecular weight relations in polystyrene. The three dotted curves show the effect of partial draining according to the Kirkwood-Riseman theory, Eqs. (50), (51) and (62), with three different choices of drainage parameter...

It is an easy matter also to investigate the effects of partial draining on the Mandelkem-Flory number ft. From Eqs. (72), (74), and (74 ) we have... 

The BBB coil is so highly expanded that it behaves as a partially draining or free draining coil, in which case d In 0/d In M is very large. For a free draining coil we should put... 

As an example of the use of Eq. (28) (p. 114), the data for fractions of cellulose carbanilate, the molecule of which can be represented by a partially drained worm-like coil, are plotted in Fig. 64. The dependence of the expression of the left-hand side of Eq. (28) on is approximated by a straight line the slope of whidi yields the length of the Kuhn segment A and the intercept the hydrodynamic diameter of the chain d. The curves in Fig. 64 provide the values of A = 160 A and d = 6 A for the cellulose carbanUate chain. 

It should be pointed out that in the Zimm, or impermeable coil, limit the specific value of R ff is uninfluential since the friction coefficient C( ) = C/v( ) is independent of R ff, see Eqs. (3.1.7 ) and (3.1.9), v( ) > 1. This is not true in the partial-draining case, in which v(q) is of order unity although larger than the Rouse free-draining limit v(q) = 1, and its full expression must be considered. 

Peitzsch RM, Burt MJ, Reed WF. Evidence of partial draining for linear polyelectrolytes heparin, chondroitin 6-sulfate, and poly(styrenesulfonate). Macromolecules 1992 25 806-815. 

The crucible containing the zirconium sponge and MgClj is transferred to the vacuum distillation retort, shown in Fig. 7.13, where it is supported, upside down, over a perforated, stainless steel funnel. The air in the retort is evacuated, and the crucible is heated to 900 to 920°C to melt the MgGj. which partially drains off the sponge. Salt still wetting the sponge is distilled at this temperature to a water-cooled jacket inside the retort. 

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