Sealing time

Physical tests of film impedance using an a.c. bridge have also been recommended, although the correlation with corrosion resistance is necessarily empirical. Film impedance increases at an approximately linear rate with sealing time and film thickness. 

Further improvement of the centroid method came with the introduction of centroid dynamics.Here the fundamental idea is to construct a centroid Hamiltonian in the full phase space of the system and the bath. The Boltzman factor is then the one obtained from this centroid Hamiltonian while seal time dynamics is obtained by running classical trajectories. This method has been applied to realistic systems " and recently derived from first principles.244 The main advantage of the centroid methodology is that thermodynamic quantum effects can be computed numerically exactly as it is not too difficult to converge numerically the computation of the centroid potential. 

Chen, M.Y., Lonser, R.R., Morrison, P.F., Govemale, L.S. and Oldfield, E.H. (1999) Variables affecting convection-enhanced delivery to the striatum a systematic examination of rate of infusion, cannula size, infusate concentration, and tissue-cannula sealing time. J. Neurosurg., 90, 315-320. 

It is a technique suitable for automatic equipment since there is no contact between the heating device and the materials to be sealed, there are none of the problems of sticking that can arise with sealing dies or electrodes. On modern machines, even with relatively thick-walled sections, sealing times can be as little as a fraction of a second. The method is ideal for work in which thermoplastics and metal components have to be joined—as in the assembly of medical syringes and the sealing of tinplate cans. 

Once the process has been optimized, plastic conditions should be recorded such as fill time, peak pressure at fill, cavity pressure,184 melt temperature, mold temperature, melt flow rates, and gate seal time. Record all basic machines setpoints on the setup sheet such as the transfer time (fill time) and weight, overall cycle time, and total shot weight, part weight, % runner, etc. 

Acrylonitrile-butadiene rubber (NBR) may be reduced in [BMIMJfBFJ using the catalyst RuHCl(CO)(PCy3)2 [32] the saturated product is a very useful engineering polymer with applications in oil seals, timing belts, and hoses [33]. An enhanced reaction rate has been observed. The same reaction was reported in a range of haHde-free IL mixtures based on dialkylimidazolium cations and the tetrafluoro-borate anion [34]. 

Techniques should be sought for rapidly sealing matrix cracks once they form. The crack sealing time should be less than the time it takes to oxidize the fiber coating. 

Figure 5.44 Schematic description of the evolution of a porous anodic film on aluminum as a function of the sealing time at 85°C.

Sample name Description Calcination / Curing conditions Seal time ... 

The seal time is how long the sample was sealed in the polypropylene container at room temperature prior to being tested. Analysis... 

The seal time was optimized. An optimum seal time would be 8 min for freshly deionized water, whereas it could be up to 15 min for a one-month-old seal solution. 

A temperature lower than current data base results In changing primary 0-rlng sealing timing function... 

RING PRESSURE LEAR CHECK PUCES SECONDARY SEAL IN OUTBOARD POSITION WHICH MINIMIZES SEALING TIME... 

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