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Thermal conditions with step changes and ramps in air temperature (T a) are universal in buildings. However, a comprehensive understanding of the influences of these dynamic thermal factors on thermal comfort remains elusive. This study investigated the physiological and psychological responses 16 healthy college students, including thermal sensation vote (TSV), thermal pleasure (TP), positive and negative affect schedule (PANAS), skin temperature, blood pressure, wrist pulse, and electroencephalography (EEG). The experimental procedure included step-changes from an office room (26 °C) to a meeting room under five different T a (22/24/26/28/30 °C) and subsequent ramping (down/up/cycles) back to 26 °C. After these different warm/cool thermal experiences, TSVs (−0.2 to 0.2) were insignificantly different and TPs (0.2–1.6) were significantly different (P = 0.006) at neutral condition of 26 °C. Specifically, TPs under neutral conditions were higher after a warmer thermal experience than after a cooler thermal experience. Under the same T a , TSVs were significantly lower (P = 0.031) by approximately 0.5, when T a ramping down compared to ramping up and stable warm conditions. The cheek temperature showed stronger correlations with TP and PANAS scores than with other body parts. The blood pressure was weakly correlated with TSV but exhibited a strong relationship with TP. Moreover, the TP and positive emotions exhibited strong negative correlations with wrist pulses and EEG at Theta (4–8 Hz). These findings offer insights into refining the prevailing thermal comfort models when considering dynamic thermal factors in shaping thermal perceptions. • TPs at neutral condition were significantly better after warm thermal experience in summer. • TSVs were 0.5 scale higher when T a ramp up than down (P = 0.031) in warm environments. • Cheek temperature has strongest correlations with TP and PANAS than other body parts. • The blood pressures have weak relationships with TSV but strong relationships with TP. • Positive emotions have strong correlations with wrist pulse and EEG at Theta (4–8 Hz). [ABSTRACT FROM AUTHOR]

In this work, the competitive relationship between the double amorphous phases is systematically investigated to increase the high-temperature wear resistance of the self-lubricating TiAlSiCN coating. These double amorphous phases combine the SiN x phase with high-temperature resistance and the C-related phase with a low friction coefficient. An increase in the Si content facilitates the change in the phase composition. The resultant coating exhibits an adhesion strength of 153 N, a friction coefficient of 0.24 and a hardness of 25.24 GPa upon generation of the TiAlN(C), the SiN x and the C-related phase. In this case, the TiAlSiCN coating achieves long-term self-lubrication at high temperatures with the titanium alloy friction pair. This mechanism stems from the SiN x phase replacing the portion of the easily oxidized amorphous C-related phase, which yields an enhanced high-temperature wear resistance. The cutting distance of this TiAlSiCN is 120% higher than that of the TiAlCN during the high-speed cutting of the titanium alloy. This outcome provides an effective solution for high-temperature applications of self-lubricating coatings. • Long-term self-lubricating is remained in TiAlSiCN coating by optimal Si content. • Synergistic effect of amorphous SiN x and C-related phase is solved in TiAlSiCN. • Tool life of TiAlSiCN improved 225% by comparing with that of TiAlN. [ABSTRACT FROM AUTHOR]

In this study, we explored the role of the intrinsic defects on the tuning thermoelectric (TE) performance of Al-doped ZnO (ZnO:Al) films. The intrinsic defects of the Zn interstitial (Zn i) and the oxygen vacancy (V O) were controlled by varying the Zn content by using the radio frequency atomic source vacuum evaporation method. In the Zn-rich case, the excessive Zn formed Zn i to provide most of the carriers. V O became the main origin of the carriers with a decreasing Zn content. When the Zn content was 55.2% and 52.5%, the segregation of Zn i decreased the carrier concentration and subsequently, enhanced the resistivity and the Seebeck coefficient. The ZnO:Al film with a Zn content of 52.5% had the highest power factor of 274.03 μW·m−1·K−2 at 819 K. In addition, the higher Zn i concentration had a more prominent effect on thermal conductivity. The thermal conductivity increased to 1.756 W·m−1·K−1 from 0.608 W·m−1·K−1 with the Zn content decreasing from 55.2% to 50.6%. The ZT value reached the highest of 0.121 when the film had the optimum Zn concentration of 51.5%. This study concluded that the tuning of the intrinsic defects was an effective method to enhance the TE performance. [ABSTRACT FROM AUTHOR]

The self-lubricating TiAlTaCN coating with high-temperature resistance above 800 °C is developed using magnetron sputtering. This mechanism stems from the TaN phase is easily oxidized to form a protective Ta 2 O 5 that compensates for the insufficient antioxidant capacity of Al 2 O 3. Moreover, the TaC phase, being resistant to oxidation, contributes to achieving the self-lubrication effect with amorphous C-related phases. The cutting distance of the TiAlTaCN is 250% greater than that of the TiAlCN during the high-speed cutting of titanium alloy. These results reveal the oxidation mechanism of different carbon nitrides and provide a new solution for the self-lubricating coatings applied at high temperatures. • A new high-temperature resistant (800 °C) self-lubricating (COF=0.27) TiAlTaCN nanocomposite coating was prepared. • The Ta addition inhibits the phase transition and increases the high thermal stability from 600 °C to 1000 °C. • The wear rate of the TiAlTaCN is 38.7% lower than that of the TiAlCN at 600 °C. • The cutting distance of the TiAlTaCN is 250% higher than the TiAlCN during the high-speed cutting of titanium alloy. [ABSTRACT FROM AUTHOR]

Abstract Coating oxidation performance is a major concern in modern machining and other high temperature applications. This study presents TiAlCrN composite coatings with different Cr content prepared on a magnetron sputtering device. SEM, AFM and XRD were used to determine the structure of the coatings. It was found that the coatings show a solid solution of B1-NaCl face-centered cubic structure with [200] preferential orientation. As the Cr content increases, the particle size and roughness of the coating increase slightly, while the hardness of the coating decreases. Oxidation tests revealed that no significant oxidation occurs in all coatings below 800 °C. However, as the oxidation temperature increases to 1000 °C, the Ti 0.32 Al 0.38 Cr 0.30 N coating undergoes severe oxidation and the Ti 0.17 Al 0.19 Cr 0.64 N coating remains good. The oxide scale of the coatings after oxidation test is analysis by XPS depth profiling in details. XPS results revealed that the oxide scale of the Ti 0.32 Al 0.38 Cr 0.30 N coating changes from a dense Al rich oxide layer (800 °C) to a loose and discontinuous Ti Al rich oxide layer (1000 °C), which is the main reason for its poor oxidation resistance. However, the Ti 0.17 Al 0.19 Cr 0.64 N coating shows a top loose Ti Al rich oxide layer and a dense bottom Cr Al rich oxide layer. The presence of this dense and continuous Cr Al rich oxide layer can limit the rapid diffusion of Ti atoms to the surface while preventing the oxygen atoms from diffusing into the interior, which is the key to excellent oxidation resistance of the Ti 0.17 Al 0.19 Cr 0.64 N coatings. Highlights • The oxide scale of TiAlCrN coating was characterized by XPS depth profiling. • As the chromium content increases, the oxidation resistance of the TiAlCrN coating increases. • The excellent oxidation resistance strongly depended on the compact Cr Al rich oxide layer. • The presence of the Cr Al rich oxide layer can limit the rapid diffusion of Ti atoms to the surface. [ABSTRACT FROM AUTHOR]

Abstract Al-doped ZnO films (Zn 0.94 Al 0.06 O x) can be fabricated by thermal oxidation of evaporated metallic Zn-Al film. Oxygen defects were strongly related to oxygen pressure at a given temperature (500 °C) and duration (3 h). Under oxygen pressure of 0.021 MPa (O 2 -0.021 MPa), the main component was the Zn phase. Zn 0.94 Al 0.06 O x films were formed under oxygen pressure of 0.1 MPa and 0.12 MPa, with the conductivity and Seebeck coefficient improving simultaneously with increased oxygen pressure. The flat particles of the O 2 -0.12 MPa film weakened the electron scattering, leading to increased conductivity. Furthermore, the decrease in oxygen vacancies caused by the higher oxygen pressure increased the Seebeck coefficient. As a result, the power factor of the O 2 -0.12 MPa film was about 30 times greater than that of the O 2 -0.1 MPa film, characterized by an increasing content of singly ionised oxygen. Highlights • Carrier concentration was changed by oxygen pressure in thermal oxidation. • Power factor was affected by content of single ionised oxygen. • Conductivity and Seebeck coefficient increased simultaneously with oxygen pressure. [ABSTRACT FROM AUTHOR]