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We reported a facile approach to fabricate graphene nanoplatelets (GNPs)/epoxy composites with a novel blend method. The influence of GNPs on the thermal and electrical properties was investigated. Compounds with different GNPs content (0-8 wt%) were mixed with a Flacktek speedmixer at a speed of 3000 rpm for 5 min. The thermal conductivity of the epoxy composites with 8 wt% GNPs was 1.181 W/m K, which is increased by 627% compared with those of the neat epoxy. It is found that the thermal stability and electrical property also have a certain degree of improvement. Scanning electron microscopy images demonstrate that the structures of the composites have a closed relationship with their properties. In addition, the incorporation of GNPs in epoxy matrix indicated excellent Vickers hardness at the low weight fractions of GNPs. POLYM. COMPOS., 36:556-565, 2015.

Western and Chinese artists have different traditions in representing the world in their paintings. While Western artists start since the Renaissance to represent the world with a central perspective and focus on salient objects in a scene, Chinese artists concentrate on context information in their paintings, mainly before the mid-19th century. We investigated whether the different typical representations influence the aesthetic preference for traditional Chinese and Western paintings in the different cultural groups. Traditional Chinese and Western paintings were presented randomly for an aesthetic evaluation to Chinese and Western participants. Both Chinese and Western paintings included two categories: landscapes and people in different scenes. Results showed a significant interaction between the source of the painting and the cultural group. For Chinese and Western paintings, a reversed pattern of aesthetic preference was observed: while Chinese participants gave higher aesthetic scores to traditional Chinese paintings than to Western paintings, Western participants tended to give higher aesthetic scores to traditional Western paintings than to Chinese paintings. We interpret this observation as indicator that personal identity is supported and enriched within cultural belongingness. Another important finding was that landscapes were more preferable than people in a scene across different cultural groups indicating a universal principle of preferences for landscapes. Thus, our results suggest that, on the one hand, the way that artists represent the world in their paintings influences the way that culturally embedded viewers perceive and appreciate paintings, but on the other hand, independent of the cultural background, anthropological universals are disclosed by the preference of landscapes.

Frost damage is a common durability problem for concrete structures in cold and wet regions, and in many cases, the frost damage is coupled with fatigue loadings such as the traffic loads on bridge decks or pavements. In this paper, to investigate the basic fatigue behavior of concrete materials affected by frost damage, a mesoscale approach based on Rigid Body Spring Method (RBSM) has been developed, of which the concrete material can be divided into three parts: mortar, coarse aggregate and interfacial transition zone (ITZ) between them. First, the cyclic constitutive laws are developed at normal and shear directions for mortar and ITZ, and verified with the existing experimental data in compression and tension fatigue. Then, several levels of frost damage are introduced by different numbers of freeze-thaw cycles (FTCs), and finally, the static tests and fatigue tests are conducted using the frost damaged concrete. The simulation results on the static strength and fatigue life show a good agreement with experimental data, and found that as the frost damage level (irreversible plastic deformation) increases, not only the static strength, but also the fatigue life at each stress level will decrease. The S-N curves of frost damaged concrete still follow a linear relationship but with bigger slopes, and the frost damaged concrete will become more ductile under fatigue loadings.

Driving style is a very important indicator and a crucial measurement of a driver's performance and ability to drive in a safe and protective manner. A dangerous driving style would possibly result in dangerous behaviors. If the driving styles can be recognized by some appropriate classification methods, much attention could be paid to the drivers with dangerous driving styles. The driving style recognition module can be integrated into the advanced driving assistance system (ADAS), which integrates different modules to improve driving automation, safety and comfort, and then the driving safety could be enhanced by pre-warning the drivers or adjusting the vehicle's controlling parameters when the dangerous driving style is detected. In most previous studies, driver's questionnaire data and vehicle's objective driving data were utilized to recognize driving styles. And promising results were obtained. However, these methods were indirect or subjective in driving style evaluation. In this paper a method based on objective driving data and electroencephalography (EEG) data was presented to classify driving styles. A simulated driving system was constructed and the EEG data and the objective driving data were collected synchronously during the simulated driving. The driving style of each participant was classified by clustering the driving data via K-means. Then the EEG data was denoised and the amplitude and the Power Spectral Density (PSD) of four frequency bands were extracted as the EEG features by Fast Fourier transform and Welch. Finally, the EEG features, combined with the classification results of the driving data were used to train a Support Vector Machine (SVM) model and a leave-one-subject-out cross validation was utilized to evaluate the performance. The SVM classification accuracy was about 80.0%. Conservative drivers showed higher PSDs in the parietal and occipital areas in the alpha and beta bands, aggressive drivers showed higher PSD in the temporal area in the delta and theta bands. These results imply that different driving styles were related with different driving strategies and mental states and suggest the feasibility of driving style recognition from EEG patterns.

Strain hardening geopolymer composite (SHGC) is an alkali-activated material reinforced with randomly dispersed short fibres, which exhibits high ductility and strain hardening and multiple cracking behaviour. This paper presents an experimental study on the effect of hybrid polyvinyl alcohol (PVA) and recycled tyre steel (RTS) fibres on engineering properties of fly ash-slag based SHGC cured at ambient temperature, including flowability, setting time, drying shrinkage, compressive strength and flexural behaviour in terms of stress-deflection response, first-crack strength and flexural strength, flexural toughness and toughening mechanisms. Four mix proportions of specimens with various volume fractions of hybrid PVA and RTS fibres including 1.5% PVA, 2% PVA, 1.75% PVA + 0.25% RTS and 1.5% PVA + 0.5% RTS were considered. The results indicated that the hybridisation of PVA fibre with RTS fibre led to a significant reduction in flowability, setting time and flexural strength of SHGC. However, the resistance to drying shrinkage and compressive strength of SHGC were greatly improved. Moreover, all specimens exhibited the expected deflection hardening behaviour with multiple stable microcracks formed over the tensile face of specimens under four-point bending. The addition of RTS fibre resulted in reduced crack widths in specimens where over 90% of cracks had a width of smaller than 60 μm. The mixture containing 2.0 vol% PVA fibre can be regarded as the optimal mixture for SHGC considering the strengths and deflection (or strain) hardening behaviour.

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ZnO nanoparticles (ZnONPs) are synthesized and incorporated into soybean protein isolate (SPI) to obtain SPI/ZnONPs (SZ) films, and the morphology, size distribution, and stability are determined. The effects of different contents of ZnONPs in the SZ films on the oxygen barrier, antibacterial activity, and thermal and mechanical properties are evaluated. A ZnONPs content of 0.2% in the SZ films improves the tensile strength and microbial inhibition by 231% and 16%, respectively. The thermal stability and oxygen barrier properties of the SZ films are also enhanced with addition of ZnONPs. The ZnONPs dispersed uniformly in the SPI film enhance the interactions between SPI molecules via hydrogen bonding, and the results suggest potential application of ZnONPs in food packaging.