Quick flow

How far can smart materials go Futuristic depictions such as in the 1991 film Terminator 2 have androids made of shape-changing metal that can quickly flow and set into any desired form. A more realistic vision for the future of smart materials and systems can be viewed by observing nature. Organisms move, adapt, and evolve, and they are made of materials that are complex but have been studied by biologists for decades. 

A commonly known example of stable dissipative structures is the tur bulence (the generation of internal vortices) in quickly flowing gas or fluid. The stream, which is laminar at low velocities, jumps to the turbu lent state when passing through the bifurcation point, which is determined by the Reynolds number dependent on a combination of kinetic and vis cous parameters of the fluid medium. Tornadoes and storms that can be seen from space are amphtudinous phenomena of dissipative structures that can arise in the strongly non equflibrium atmosphere. 

High conversions and molecular weights are obtained because reversible reactions and side-product removal is not an issue. In RIM processes, liquid monomers are mixed using impinging jets and must quickly flow into the mold before the reacting mixture becomes too viscous. The complete cycle time for injection, reaction and umnolding (so that the mold can be used to make the next product) is often only 30-60 s. RIM is used to produce rigid molded polyurethane automobile parts and polyurethane foam seat cushions [3j. 

The European equivalent of C-TPAT is the Authorised Economic Operator (AEO) initiative. There are three types of AEO status AEOC, AEOS, AEOF. They differ from each other in privileges. Through the application of the security requirements a credible company operating on an international scale may gain an efficient and quick flow of goods, thanks to time saved and the reduction of red tape related to international trade and transport. These benefits result from less frequent controls of cargo and documents, easier access to customs simplifications, a reduced amount of data to be included in summary declarations, the possibility of companies receiving earlier notification of delivery controls, priority treatment of the company s shipment in the event of a check, and the possibility for the company to request that a shipment be checked in any location. 

Shell and tube exchangers seldom have pressure-relief valves for fire exposure because vapors will quickly flow to the next pressure vessel from which they can be discharged. The two-thirds rule from API RP 521 states ... 

In installations where gaseous or LP fuels are used, keep all floor drains and service trenches out of the engine enclosure. LP and some constituents of natural gas can be heavier than air and wiU quickly flow into snch low spots, creating a fire hazard. 

Greek turpentine oil is a commercial article in the South of Europe and is obtained from the Aleppo pine Pinus hcdepensis). It is produced in nearly all the provinces of Greece. It is usual either to make deep incisions in the trunks through which the resin quickly flows away, or in the French manner to cut rather shallow notches and place a wooden receptacle below these, in which the oleo-resin is collect. Pinus haie-pensis is the only tree in Greece which is used for the production of turpentine. 

In a completely automated factory environment, where the components are being moved piece by piece rather than in batches, the effect of the transporter on delay time (the non value adding time) and machine block time is important. A balance between the number of transporters on one hand and the delay and block time on the other, has to be struck for economic viability or increase the profitability of the factory. Increasing the AGVs increase the capital investment while increase in delay time and block time adds to the cost of the product without adding any value to the product. A completely automated factory is capital intensive. Therefore all effort should be directed to keep the utilization at a higher level and at the same time ensure quick flow of jobs with minimal delay time. There should also be a built-in production expansion capability for an anticipated increase in demand. This necessitates the need to identify the potential bottleneck areas. Simulation plays an important role in this identification. 

---