Effect of Nonlinear Elasticity on the Swelling Behaviors of Highly Swollen Polyelectrolyte Gels

Polyelectrolyte gels exhibit swelling behaviors that are dependent on the external environment. The swelling behaviors of highly charged polyelectrolyte gels can be well explained using the Flory–Rehner model combined with the Gibbs–Donnan effect and Manning’s counterion condensation effect (the FRGDM model). This study investigated the swelling properties of a series of model polyelectrolyte gels, namely tetra-polyacrylic acid-polyethylene glycol gels (Tetra-PAA-PEG gels), and determined the applicability of the FRGDM model. The swelling ratio (Vs/V0) was well reproduced by the FRGDM model in the moderate swelling regime (Vs/V0 < 10). However, in the high swelling regime (Vs/V0 > 10), the FRGDM model is approx. 1.6 times larger than the experimental results. When we introduced the finite extensibility to the elastic free energy in the FRGDM model, the swelling behavior was successfully reproduced even in the high swelling regime. Our results reveal that finite extensibility is one of the factors determining the swelling equilibrium of highly charged polyelectrolyte gels. The modified FRGDM model reproduces well the swelling behavior of a wide range of polyelectrolyte gels.

A Fast Drying Machine Based On Semiconductor Heat Pump

The new latent heat recovery type semiconductor heat pump ground fast dryer is a kind of integrated semiconductor refrigeration module on the traditional dryer. We simulated the process of the wind being heated by the hot end of the semiconductor refrigeration module under different working conditions through ANSYS software, so as to obtain the best solution for the semiconductor refrigeration module. Using the principles of drying and air condensation, we calculated the influence of the drying rate, drying time, and the condensation effect of the cold end when the air at different hot end inlet wind speeds, ambient temperature and moisture content blows the same amount of moisture on the ground. Through energy-saving analysis, our design saves about 60% energy compared with traditional electric heating style hair dryers. In the case of the same input power, the outlet air temperature of the semiconductor heat pump ground rapid dryer is significantly higher than that of the electric heating hair dryer. Therefore, when the ground is dry with the same amount of moisture, the use of the new semiconductor heat pump ground rapid dryer can significantly shorten drying time, the best drying time shortening rate is as high as 70%.

Measuring Time with Minimal Clocks

Being able to measure time, whether directly or indirectly, is a significant advantage for an organism. It allows for timely reaction to regular or predicted events, reducing the pressure for fast processing of sensory input. Thus, clocks are ubiquitous in biology. In the present article, we consider minimal abstract pure clocks in different configurations and investigate their characteristic dynamics. We are especially interested in optimally time-resolving clocks. Among these, we find fundamentally diametral clock characteristics, such as oscillatory behavior for purely local time measurement or decay-based clocks measuring time periods on a scale global to the problem. We include also sets of independent clocks ( clock bags), sequential cascades of clocks, and composite clocks with controlled dependence. Clock cascades show a condensation effect, and the composite clock shows various regimes of markedly different dynamics.

RANS Simulation of a Radial Compressor With Supercritical CO2 Fluid for External Loss Model Development

From the observation of previous experimental results, it was recognized that the amount of external losses at the external flow paths can be substantial. Understanding the external loss mechanisms, and reducing the external losses are crucial to the design of a high performance S-CO2 compressor. Therefore, this study first focused on verifying the existing external loss models by estimating the internal loss accurately through a high fidelity CFD calculation and then substituting from the total losses. By analyzing the CFD result and energy balance data obtained from the experiment, the authors are suggesting the best combination of the external loss models for the S-CO2 compressor. This is followed by the investigation of the condensation effect in the impeller by utilizing a two-phase VOF model with metastable properties. As a result, it is re-confirmed that there is a negligible amount of condensation effect.

Condensation effect-induced improved sensitivity for SERS trace detection on a superhydrophobic plasmonic nanofibrous mat

Superhydrophobic PAN/noble metal nanofibrous mats prove to be highly SERS-sensitive substrates for the trace detection of analyte molecules due to the condensation effect.