Osmotic shock in a vesicle or cell is the stress build-up and subsequent rupture of the phospholipid membrane that occurs when a relatively high concentration of salt is unable to cross the membrane and instead an inflow of water alleviates the salt concentration gradient. This is a well-known failure mechanism for cells and vesicles (for example, hypotonic shock) and metal alloys (for example, hydrogen embrittlement). We propose the concept of collective osmotic shock, whereby a coordinated explosive fracture resulting from multiplexing the singular effects of osmotic shock at discrete sites within an ordered material results in regular bicontinuous structures. The concept is demonstrated here using self-assembled block copolymer micelles, yet it is applicable to organized heterogeneous materials where a minority component can be selectively degraded and solvated whilst ensconced in a matrix capable of plastic deformation. We discuss the application of these self-supported, perforated multilayer materials in photonics, nanofiltration and optoelectronics.

Cavity-wall interactions play an important role in determining the dynamics of supercavitating vehicles. To date, supercavitating vehicle system models make use of constant cylindrical cavities. As a further step, in this work, a dive-plane model with noncylindrical and nonsymmetric cavity shapes is developed. Cavitator angle of attack effects are considered, and a noncylindrical planing force model is incorporated. The system dynamics is examined in terms of nonlinear instabilities and the tail-slap phenomenon, and it is shown that the cavity shape plays a critical role in determining the system dynamics. The effectiveness of feedback control strategies with fin and cavitator inputs to achieve vehicle stability is also discussed.

This article presents the catalysis investigation of octanethiolate-capped palladium nanoparticles (C8 PdNP) and phenylethanethiolate-capped palladium nanoparticles (PhC2 PdNP) for chemoselective catalytic hydrogenation reactions of styrene derivatives in the presence of other reducible functionalities. The results show that the C8 PdNP is highly active under mild reaction conditions (room temperature and atmospheric pressure) and selective for hydrogenating monosubstituted alkene groups without reducing other reactive functional groups such as nitro, halo, carbonyls, and so forth. In comparison, the noncovalent interactions between surface phenyl ligands and aromatic substrates are found to hinder the hydrogenation activity of PhC2 PdNP.

A pitch-plane model of a supercavitating vehicle is developed to account for the time delay in the propagation of the cavitator action from the vehicle nose to the vehicle aft. This time delay is an advection delay, which is on the order of the vehicle length divided by its speed. Unlike previous models with time-delay effects, in the present model, the effect of cavity rotation during forward motion is incorporated. Stability analyses and feedback control designs are carried out using this model. It is found that the open-loop system with and without the time delay is unstable. Feedback control laws that stabilize the delay-free system model are found to be ineffective in the presence of the time delay. The authors show that the delay leads to destabilization of the supercavitating vehicle dynamics in the sense that an operation at a stable trim condition is replaced by a stable limit-cycle motion that is commonly referred to as tail-slap. Feedback control designs are carried out by taking into account the time delay, and it is demonstrated that the supercavitating vehicle can be stabilized at trim conditions inside and outside the cavity. By using numerical studies of the nonlinear delay-dependent pitch-plane model of the supercavitating vehicle, the effectiveness of the new control designs are demonstrated.

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