Closed system isolation

Any chemical, biological, or mechanical system in which both heat and matter within the system can be transferred to and from its surrounding environment. Thus, a change in the immediate environment can result in a change in the system under consideration. See also Closed System Isolated System... 

A term used in thermodynamics to designate a region separated from the rest of the universe by definite boundaries. The system is considered to be isolated if any change in the surroundings the portion of the universe outside of the boundaries of the system) does not cause any changes within the system. See Closed System Isolated System Open System... 

Explain the following terms thermochemistry, system, surroundings, open system, closed system, isolated system, exothermic process, endothermic process. 

Reactor coolant pressure boundary penetrat i ng conta i nment Primary containment isolation Closed system isolation valves... 

Criterion 57 - Closed system isolation valves. Each line that penetrates primary reactor containment and is neither part of the reactor coolant pressure boundary nor connected directly to the containment atmosphere shall have at least one containment isolation valve which shall be either automatic, or locked closed, or capable of remote manual operation. This valve shall be outside containment and located as close to the containment as practical. A simple check valve may not be used as the automatic isolation valve. 

The whole sample, consisting of crystals and melt, is enclosed in the sample holder of the calorimeter (see Sects. 4.2-4.4), making it the overall closed system, isolated from the surroundings. As melting progresses, mass is transferred in Fig. 2.82 from the left to the right. On crystallization, the mass transport goes in the opposite direction. The heat transport across the open boundary is minimal since it is assumed that the calorimeter remains at constant temperature. 

Closed system isolation These are the lines that penetrate the containment. However, they are neither part of fhe reactor coolant pressure boundary nor are they connected directly to the containment atmosphere. 

Open system Closed system Isolated system ... 

An explicit example of an equilibrium ensemble is the microcanonical ensemble, which describes closed systems with adiabatic walls. Such systems have constraints of fixed N, V and E < W< E + E. E is very small compared to E, and corresponds to the assumed very weak interaction of the isolated system with the surroundings. E has to be chosen such that it is larger than (Si )... 

As soon as the wort is cooled to <50° C it becomes an excellent culture medium for microorganisms. Therefore, the modem apparatus, in which the wort is cleared and cooled, is a closed system, completely isolated from the influence of microorganisms in the air, and is much safer in contrast to the old open coolships and open cooler. 

Generally, in a system that is energetically and materially isolated from the environment without a change in volume (a closed system), the entropy of the system tends to take on a maximum value, so that any macroscopic structures, except for the arrangement of atoms, cannot survive. On the other hand, in a system exchanging energy and mass with the environment (an open system), it is possible to decrease the entropy more than in a closed system. That is, a macroscopic structure can be maintained. Usually such a system is far from thermodynamic equilibrium, so that it also has nonlinearity. 

Identify the following systems as open, closed, or isolated (a) coffee in a very high quality thermos bottle (b) coolant in a refrigerator coil (c) a bomb calorimeter in which benzene is burned (d) gasoline burning in an automobile engine ... 

Self-organization seems to be counterintuitive, since the order that is generated challenges the paradigm of increasing disorder based on the second law of thermodynamics. In statistical thermodynamics, entropy is the number of possible microstates for a macroscopic state. Since, in an ordered state, the number of possible microstates is smaller than for a more disordered state, it follows that a self-organized system has a lower entropy. However, the two need not contradict each other it is possible to reduce the entropy in a part of a system while it increases in another. A few of the system s macroscopic degrees of freedom can become more ordered at the expense of microscopic disorder. This is valid even for isolated, closed systems. Eurthermore, in an open system, the entropy production can be transferred to the environment, so that here even the overall entropy in the entire system can be reduced. 

Figure 3.1 Schematic representations of thermodynamic systems a) isolated system, b) closed system and c) open system...

Most individual biochemical reactions are reversible and are therefore quite correctly considered to be chemical equilibria, but cells are not closed systems fuel (e.g. a source of carbon and, in aerobic cells, oxygen) and other resources (e.g. a source of nitrogen and phosphorus) are continually being added and waste products removed, but their relative concentrations within the cell are fairly constant being subject to only moderate fluctuation. Moreover, no biochemical reaction exists in isolation, but each is part of the overall flow of substrate through the pathway as a whole. 

Figure 8. Example of apparent closed-system equilibrium fractionation, where Mo in solution is sorbed to Mn oxides (Barling and Anbar 2004). The 6 Mo values of the Mo remaining in solution during sorption follow die linear trends that are consistent widi closed-system equilibrium fractionation where isotopic equilibrium is continuously maintained between Mo in solution and diat sorbed to die Mn oxides. Three aqueous-solid pairs (shown widi tie lines) are consistent with this interpretation. The isotopic data cannot be ejqilained dirough a Rayleigh process, where die product of die reaction (sorbed Mo) is isolated from isotopic exchange widi aqueous Mo.

If such a reaction is isolated from its surroundings, so that A and B neither enter nor leave the system, creating a closed system, these reactants will eventually reach equilibrium, i.e. the forward and reverse rates are the same. For a closed system, equilibrium is the only state in which the concentrations of A and B do not vary with time. Since AG = 0, the reaction can do no useful work and has no direction. Hence a closed system is not a useful model of a living cell or, indeed, a living animal. 

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