Expansion and contraction dynamics

Nanometer Expansion and Contraction Dynamics of Polymer Films Induced by Nanosecond Laser... 

Figure 3. Expansion and contraction dynamics of PMMA film at the fluence of 700 mJ/cm (A) and 540 mJ/crn (O) below the swelling threshold. A solid curve represents an excimer laser pulse, and an error bar is included.

At 248 nm excitation, expansion and contraction dynamics of polyimide film is given in Figure 6 at the fluence of 20 mJ/cm. The irradiated film began to expand during the excimer laser pulse and contracted rapidly, ose rate was about 1 nm/ns and 0.1 nm/ns, respectively. The maximum expansion amplitude was attained when the excitation pulse ends, and the expansion disappeared completely after a few ms. 

First we consider that the different expansion behavior at 248 nm aiul 351 nm excitation is due to the different etching mechanism discussed above. In the case of 351 nm excitation, multiphoton photochemical and photothermal processes are involved and the latter may be more important at lower fluence. The contraction behavior at 80 mJ/cm may reflect slow heat dissipation in polyimide, which behavior is actually consistent with photothermal expansion and contraction dynamics of PMMA film (21). On the other hand, toe thin surface layer is excited at 248 nm, so that heat dissipation to quartz substrate should be slower than that at 351 nm. More quantitative analysis of cooling processes by the simulation was conducted to understand the expansion and contraction dynamics. 

Figure 6, Expansion and contraction dynamics of polyimide film at the fiuence of 20 mJ/cm below the ablation. The solid and dashed curves represent the time profiles of the excimer laser pulse and time-integration of the laser pulse, respectively, while the dotted and dash-dotted curves are simulated surface temperature rise at the fiuence of 20 mJ/crn and 30 mJ/cm, respectively. Excitation wavelength is 248 nm. An error bar is included.

Figure 7. Expansion and contraction dynamics of polyimide film at the fiuence of 80 mJ/cm (O) and 130 mJ/cm (A) below the ablation threshold.

Also in the long term, the equipment loses its eflicieney, and replacement parts are substituted in a maintenance function. Also, the plant goes through production expansions and contractions new equipment is added into the pipes. In short, the system and its elevations and pressures, its resistances and velocities, are very dynamic. The BEP of the pump is static. 

In Briah, polar opposition first appears as cosmic day and night, expansion and contraction, force and form, and a whole host of opposing yet complementary aspects. All are necessary for dynamic existence, for movement, alternation, and progression. These principles embody and express the spiritual laws of rhythm and polarity. 

As we shall have occasion to note in dealing with solutions, the composition of the surface phase is very different from that of the bulk liquid. When a liquid interface is newly formed the system is unstable until the surface phase has acquired its correct excess or deficit of solute by diffusion from or into the bulk of the solution. This process of diffusion is by no means instantaneous and, as has been observed in discussing the drop weight method, several minutes may elapse before equilibrium is established. In the ripple method the surfece is not renewed instantaneously but may be regarded as undergoing a series of expansions and contractions, thus we should anticipate that the value of the surface tension of a solution determined by this method would lie between those determined by the static and an ideal dynamic method respectively. 

In the catalyst reoxidation step, contrary to the electron-transfer step, the polymer ligand should shrink because of the formation of the Cu(II) complex. Therefore, the polymer chain may partially repeat are expansion and contraction occurring during the catalytic cycle. When one has a view of the polymer-Cu catalyst as a whole, each part of the polymer catalyst domain, which is drifted in solution, is seen to be fluctuating during the catalytic process [Fig. 32(b)]. The fluctuating shape of biopolymers in enzymic reactions has been pointed out, and the dynamically conformational change of a flexible polymer chain is considered to be one of the effects of the polymer catalyst. 

Kyvik, S. (2009). The dynamics of change in higher education Expansion and contraction in an organisational field. Springer Science-H Business Media B.V. 

Wilhelm W, Han X, Lee C (2013) Computational comparison of two formulations for dynamic supply chain reconfiguration with capacity expansion and contraction. Comput Oper Res 40 2340-2356... 

During dynamic tests with thermal, load, and shutdown-start-up cycling, the amount and the vapor pressure of the water product varies and formation of liquid water might be involved. In addition, the shutdown-start-up or/and temperature cycling cause thermal and mechanical stresses to the membranes and cell components as well as volume expansions and contractions of the acid in the MEAs. Another important mechanism of the cell degradation involved in these dynamic tests is the corrosion of carbon supports and growth of noble metal catalysts [10]. Some dynamic test results are summarized in Table 22.10. 

TABLE 2-14 Dynamic Loss Factor K for Expansions and Contractions, where Loss KV 2g ... 

The sealant in the joint must accommodate these movements considering the actual joint width when the sealant is inserted and cured or set. The necessary joint widths to accommodate joint expansion and contraction are easily calculated from the elongation capabilities of the sealant in tensile and compression. These values are standard information in the technical data sheets of sealants, often using the term dynamic movement capability and expressed as a percentage. Where only one value is given, it should be used for both tension and compression. Calculation of these minimum widths is accomplished using the following relationships ... 

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