The performance, including deterioration resistant coefficient of compressive strength, relative dynamic elastic modulus (RDEM) and microstructure, of concretes were evaluated after being subjected to certain freezing-thawing cycles in sodium sulfate solution.
For some of the considered heat transfer modes, heat transfer coefficient deterioration or no effect were also recorded; however, these occurrences were low.
Das et al. [15] reported that nanofluids that exhibit nucleate boiling heat transfer coefficient deterioration typically have high particle concentrations (4% to 16% by weight), while enhancement is typically found at relatively low particle concentrations (<1.25% by weight).
Thus, the change in contact angle can explain a significant portion of the deterioration of heat transfer coefficient in nanofluids.
However, they also noted a deterioration in the BHT coefficient, which could have been an unfortunate result of the nanoparticle-fouled surface.
Oppositely, the FQ process with the slowest cooling rate leads to decreasing of friction coefficient and deterioration of wear resistance of PDC.
While in application, MFCs are subjected to continuous cyclic mechanical load which may lead to the deterioration of piezoelectric coupling coefficient, thereby affecting its sensing performance.
However, this nanoparticle layer is also considered by some researchers to be also responsible for the deterioration found in the BHT coefficient.
There is also weak statistical indication of nanofluids causing deterioration of the heat transfer coefficient (11% of the sample) and an even smaller percentage of the sample indicating no enhancement at all (3% of the sample).
Firstly, the effect of fundamental-frequency estimation error on direct TDA is investigated, and it indicates that minor error of estimation can cause severe deterioration in curve of attenuation coefficient.
