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A uniform antiplane fault model obeying the rate‐ and state‐dependent friction law and surrounded by a steady‐slipping region with a constant loading rate is studied through quasi‐dynamic numerical method. Findings indicate that the model exhibits scale‐dependent slip characteristics. Previous studies have demonstrated that the fault slip pattern changes from aseismic creep or slow earthquakes to seismic instabilities as the fault length W increases from around the nucleation size hc to well above hc. In the latter, instabilities typically nucleate periodically from the center of the fault and develop into characteristic events after the whole fault reaches a background stress level. For a fault with larger W/hc, characteristic events nucleate near the boundary or alternatively from both sides before the entire fault returns to background level. As W/hc increases further, additional events with rupture size between hc and W appear. The number of small events is expected to increase with W/hc. The reason these small events do not rupture the whole fault is that the locked region forming on the fault when nucleation occurs acts as a large and low stress barrier. These small events continually create stress concentrations that serve as preparations for the next larger earthquake until the final characteristic event occurs. Meanwhile, the fault in this process gradually evolves into extreme sensitivity that any slight perturbation could change the original slip pattern. Although the current result is far from explaining the observed slip complexity on natural faults, it suggests a trend of increasing slip complexity with W/hc. Therefore, our understanding of the fault behavior may differ from previous knowledge that a relatively uniform and isolated fault model obeying the rate‐ and state‐dependent friction law only exhibits periodic or aperiodic system‐size events.

Stress development in coatings prepared from aqueous suspensions of hard particles was monitored using a modified cantilever deflection technique that suppresses lateral drying fronts. Without complications from lateral drying, stress development was found to be negligible until a critical amount of drying when stress increases dramatically to a maximum and then falls more slowly as drying completes. In addition, the maximum stress measured for coatings prepared on the modified cantilevers was more than double the maximum stress for coatings measured on standard cantilevers where lateral drying fronts were present. By achieving drying uniformity, direct correlations were made between the microstructure of the coating and the measured coating stress. Cryogenic scanning electron microscopy (cryoSEM) was used to image the microstructure of aqueous alumina and silica particle coatings during the intermediate stages of drying. CryoSEM revealed that stress increases dramatically once the particles form a saturated close‐packed network, and that stress decays as water evaporates from the pore structure.

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a b s t r a c tAirborne transmission is a main spread mode of respiratory infectious diseases, whose frequent epidemic has brought serious social burden. Identifying possible routes of the airborne transmission and predicting the potential infection risk are meaningful for infectious disease control. In the present study, an internal spread route between horizontal adjacent flats induced by air infiltration was investigated. Onsite measurements were conducted, and tracer gas technique was employed. Two measurement scenarios, closed window mode and open window mode, were compared. Using the calculated air change rate and mass fraction, the cross-infection risk was estimated using the WellseRiley model. It found that tracer gas concentrations in receptor rooms are one order lower than the source room, and the infection risks are also one order lower. Opening windows results in larger air change rate on the one hand, but higher mass fraction on the other hand. Higher mass fraction not necessarily results in higher infection risk as the pathogen concentration in the source room is reduced by the higher air change rate. In the present study, opening windows could significantly reduce the infection risk of the index room but slightly reduce the risks in receptor rooms. The mass fraction of air originated from the index room to the receptor units could be 0.28 and the relative cross-infection risk through the internal transmission route could be 9%, which are higher than the external spread through single-sided window flush. The study implicates that the horizontal transmission route induced by air infiltration should not be underestimated.

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Abstract. Dynamically linked libraries are commonly used in software programs to facilitate code reuse. Once a library is linked into a software program, a bug in the library can lead to compromise of the whole program. Moreover, the library may also contain malicious code. Existing solutions for software component isolation assume simple interactions between a library and the main program, otherwise, they require significant modification of the main program and the library. In this paper, we propose a novel solution, Codejail, which supports a partial isolation of libraries that have tight memory interactions with the main program. Codejail requires no modification to the main program or the library. We demonstrate using a Linux prototype that Codejail can work easily with real-world programs and libraries. The performance is good for a portable implementation with costs commensurate with the degree of tight interaction.