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Abstract:A new structure bulk tobacco curing barn was presented. To study the temperature and humidity field in the new structure tobacco curing barn, a 3D transient computational fluid dynamics (CFD) model was developed using porous medium, species transport, κ-ε turbulence and discrete phase models. The CFD results demonstrated that (1) the temperature and relative humidity predictions were validated by the experimental results, and comparison of simulation results with experimental data showed a fairly close agreement; (2) the temperature of the bottom and inlet area was higher than the top and outlet area, and water vapor concentrated on the top and outlet area in the barn; (3) tobacco loading density and thickness of tobacco leaves had an explicit effect on the temperature distributions in the barn.

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The formation of ice hangings on the surfaces of concrete tunnel linings and sloped rock masses in cold regions endangers railroad and highway traffic. However, an inexpensive anti-icing material that meets both performance and cost requirements has not yet been developed for application in tunnel and slope engineering infrastructures in cold regions. Most current advanced anti-icing materials are expensive, and fabrication and spraying are both cumbersome, which limits their widespread application to tunnel and slope engineering. Because concrete is a widely used construction material owing to its excellent mechanical properties and low cost, we developed an inexpensive, environmentally friendly anti-icing concrete material (AICM). The AICM can be easily fabricated and sprayed onto the surfaces of large-area concrete or rock substrates and exhibits excellent superhydrophobicity (CA: 151°, SA: 6.7°), surface robustness, water resistance, chemical durability, good anti-icing, easy deicing (deicing stress: 0.06 MPa), and excellent long-term durability in freeze−thaw cycles in low-temperature environments. In addition, a novel fractal theory-based model of ice adhesion shear stress was developed and revealed the mechanism through which an AICM with a composite micro/nanostructure easily deices. The AICM has good application prospects and serves as an important guide for mitigating the formation of ice hangings in tunnel and slope engineering infrastructures in cold regions.