42 research outputs found
Reversible shear thickening at low shear rates of electrorheological fluids under electric fields
Shear thickening is a phenomenon of significant viscosity increase of
colloidal suspensions. While electrorheological (ER) fluids can be turned into
a solid-like material by applying an electric field, their shear strength is
widely represented by the attractive electrostatic interaction between ER
particles. By shearing ER fluids between two concentric cylinders, we show a
reversible shear thickening of ER fluids above a low critical shear rate (<1
s-1) and a high critical electric field strength (>100 V/mm), which could be
characterized by a modified Mason number. Shear thickening and electrostatic
particle interaction-induced inter-particle friction forces is considered to be
the real origin of the high shear strength of ER fluids, while the applied
electric field controls the extent of shear thickening. The electric
field-controlled reversible shear thickening has implications for
high-performance ER/magnetorheological (MR) fluid design, clutch fluids with
high friction forces triggered by applying local electric field, other
field-responsive materials and intelligent systems.Comment: 29pages, 9 figure
The impact of non-breaking surface waves in upper-ocean temperature simulations of the Last Glacial Maximum
Widespread mismatches between proxy-based and modelling studies of the Last Glacial Maximum (LGM) has limited better understanding about interglacial-glacial climate change. In this study, we incorporate non-breaking surface waves (NBW) induced mixing into an ocean model to assess the potential role of waves in changing a simulation of LGM upper oceans. Our results show a substantial 40 m subsurface warming introduced by surface waves in LGM summer, with larger magnitudes relative to the present-day ocean. At the ocean surface, according to the comparison between the proxy data and our simulations, the incorporation of the surface wave process into models can potentially decrease the model-data discrepancy for the LGM ocean. Therefore, our findings suggest that the inclusion of NBW is helpful in simulating glacial oceans
Calcineurin and Calcium Channel CchA Coordinate the Salt Stress Response by Regulating Cytoplasmic Ca 2+
Surface dynamics at photoactive liquid crystal polymer networks
\u3cp\u3eThe field of advanced and responsive soft materials is at the edge of a new era. After several decades during which liquid crystals generated new functions for information displays and could solve many problems in emerging fields such as (tele)communications, this material system is being utilized to reach out to completely new application fields with functions that can take over biological actions (cell growth and manipulation), change the way materials, machines, or robots interact with humans (haptics), and modulate surface properties, e.g., tribology and wettability. This Progress Report concentrates on creating surface movement in liquid crystal networks with an emphasis on the light-responsive dynamic surface topographies that transfer from a flat to a predesigned corrugated state via light illumination, e.g., UV and visible light. Within this framework, the interaction between dynamic surfaces and the environment, such as controlled friction, wettability, and material transport, are illustrated. In addition, the light-induced thermal effect is discussed. The article concludes with the existing challenges and an outlook on the opportunities.\u3c/p\u3