Microfluidics based on ZnO/nanocrystalline diamond surface acoustic wave devices

Surface acoustic wave (SAW) devices with 64 μm wavelength were fabricated on a zinc oxide (ZnO) film deposited on top of an ultra-smooth nanocrystalline diamond (UNCD) layer. The smooth surface of the UNCD film allowed the growth of the ZnO film with excellent c-axis orientation and low surface roughness, suitable for SAW fabrication, and could restrain the wave from significantly dissipating into the substrate. The frequency response of the fabricated devices was characterized and a Rayleigh mode was observed at ∼65.4 MHz. This mode was utilised to demonstrate that the ZnO/UNCD SAW device can be successfully used for microfluidic applications. Streaming, pumping, and jetting using microdroplets of 0.5 and 20 μl were achieved and characterized under different powers applied to the SAW device, focusing more on the jetting behaviors induced by the ZnO SAW.     

Brazilian adolescents' prosocial moral judgment and behavior: relations to sympathy, perspective taking, gender-role orientation, and demographic characteristics

The goal of this study was to examine demographic and individual difference variables that predict level of prosocial moral judgment and self-reported prosocial behavior and to test mediating or moderating relations among predictors. The relations of prosocial moral reasoning and self-reported prosocial behavior to perspective taking, sympathy, age, sociometric status, and gender-role orientation were examined with a sample of 149 Brazilian adolescents who completed a series of questionnaire measures. Prosocial moral judgment was expected to be predicted by both sympathy and perspective taking, whereas sympathy or prosocial moral judgment was expected to mediate the relations of femininity and perspective taking to prosocial behavior. Self-reported perspective taking and sympathy interacted when predicting prosocial moral judgment; adolescents who were high in either sympathy or perspective taking (or both) scored high in prosocial moral reasoning. A feminine orientation predicted sympathy and perspective taking, perspective taking predicted prosocial moral reasoning and sympathy, and sympathy had both direct and indirect paths (through moral judgment) to prosocial behavior. The findings generally were consistent with the contention that both the tendency to take others' perspectives and to sympathize are related to level of prosocial moral reasoning, which in turn motivates prosocial behavior. Moreover, patterns of correlations among variables were similar to those found in the United States.     

Almost sure weak exponential stability with a certain decay function of semilinear stochastic evolutionequations

In this paper the weak exponential stability with decay function of sample path, which are given by mild solution to a class of semilinear stochastic evolution equations, are presented. The analyses consist in using exponential martingale formula, Lyapunov functional and some special inequalities derived for our stability purposes. Two examples are given to illustrate the theory.     

Tunable visual color filter using microfluidic grating

This paper reports a tunable visual color filter based on a microfluidic transmission grating. The grating lines are formed by the microflows in an array of evenly spaced straight microchannels. In experimental study, the transmission of white light measures a shift of visual color from red to blue in the zeroth order diffraction in response to a change of the refractive index from 1.3290 to 1.3782 in the microflows. The merit of large tunability of transmission peak (Δλ=408 nm) makes this grating potential for various applications in biological and chemical measurements, such as space- and time-resolving micropattern spectrophotometers and separation of the fluorescence from the excitation.