Electromechanical responses of piezoelectric fiber composites with sliding interface under anti-plane deformations

This paper deals with the analysis of electromechanical responses of piezoelectric fibrous composites with viscous interface. A model consisting of a matrix and unidirectionally arranged fibers is examined. The composite is assumed to undergo a longitudinal shear stress with a transverse electric field, thus deforms in the anti-plane state. By charactering the viscous interface with a law of linear rheology, an analytical solution is obtained for the evolving mechanical and electric fields around an isolated cylindrical inclusion embedded in an infinite matrix. The result is then used to study the overall behavior of the composite based on the Mori–Tanaka mean field approximation.     

Mass transfer in cellular material at solid–liquid contacting interface

The effective mass transfer (water and solute) and volume shrinkage were measured during solid–liquid contacting process for red beet material tissue under a wide range of process parameters. The mass transfer process of each component in the solid–liquid system is affected not only by operating parameters, but also by the matrix properties of cellular material. The main driving force for the mass transfer phenomena of water out of red beet tissue and sucrose taken into red beet tissue from sucrose solution is attributed to the concentration gradient between external and internal red beet material, and the interaction among water, sucrose fluxes and tissue matrix. The coupled mass transfer fluxes across the interface in an isothermal solid–liquid system were analysed by means of a film model as a function of the concentration gradients, based on the generalized multicomponent mass transfer theories. The relation between individual flux and the independent driving force is nonlinear. The mass transfer model and parameters proposed in the present study is applicable to the unit operation such as osmotic treatment of cellular porous biomaterial.     

膨化苦荞麦茶泡茶特性研究

以高温短时气流膨化苦荞麦茶为原料,以感官评分、黄酮浓度和DPPH清除率为指标,研究其泡茶方法和茶水放置条件对苦荞麦茶水性质的影响。结果表明,料液比、冲泡温度、冲泡时间和冲泡次数对苦荞麦茶水感官品质、黄酮浓度和DPPH抗氧化活性有显著影响,在料液比为1:25,用100℃沸水第1次冲泡15min时茶水的品质最好。同时研究表明,膨化苦荞麦茶可进行多次冲泡,且冲泡8h内茶水中黄酮及其功能性对光照具有良好的稳定性。     

Efficient framework for mobile walkthrough application

The past few years have witnessed a dramatic growth in the number and variety of graphics intensive mobile applications, which allow users to interact and navigate through large scenes such as historical sites, museums and virtual cities. These applications support many clients and impose a heavy requirement on network resources and computational resources. One key issue in the design of cost efficient mobile walkthrough applications is the data transmission between servers and mobile client devices. In this paper, we propose an effective progressive mesh transmission framework that stores and divide scene objects into different resolutions. In this approach, each mobile device progressively receives and processes only the object’s details matching its display resolution which improves the overall system’s response time and the user’s perception. A fine grained cache mechanism is used to keep the most frequently requested objects’ details in the device memory and consequently reduce the network traffic. Experiments, in simulated and real world environment, are used to illustrate the effectiveness of the proposed framework under various settings of the virtual scene and mobile device configuration. Experimental results show that the proposed framework can improve the walkthrough system performance in mobile devices, with a relatively small overhead.     

The utilization of carbon nitride to reinforce the mechanical and thermal properties of UV-curable waterborne polyurethane acrylate coatings

The waterborne polyurethane-acrylate (WPUA and Wsi-PUA) oligomers were prepared by anionic self-emulsifying method, using isophorone diisocyanate (IPDI), polyethylene glycol (PEG), dimethylol propionic acid (DMPA), vinyl hydroxyl silicone oil (VHSO) and hydroxyethyl methyl acrylate (HEMA) as raw materials. Then, a series of UV-curable waterborne Wsi-PUA–C₃N₄ composites containing different content of g-C₃N₄ were obtained with oligomer and photoinitiator Darocur 1173. FTIR, XRD, TEM, SEM, and TGA were employed to investigate the structure, morphology and thermal property of the Wsi-PUA–C₃N₄ composite films. The effect of g-C₃N₄ content on the performance was also investigated. The mechanical performance, water resistance and gel content of UV-PUA films were measured. It was found that with g-C₃N₄ particle was introduced into Wsi-PUA oligomer, the hardness, tensile strength, gel content, water resistance and thermal stability of composite films were significantly augmented. Moreover, when the content of g-C₃N₄ was 1.0 wt.%, the UV-curable film had the best mechanical property. The obtained composite is promising for a number of applications, e.g., for protecting the surfaces of metal and wood.     

‘Land for infrastructure’ in Ho Chi Minh City: land-based financing of transportation improvement

This paper explores how land-based financing mechanisms are currently used in Ho Chi Minh City as a public-private funding strategy. The Land-for-Infrastructure (LFI) mechanism appears as a solution to produce infrastructures. We found that the implementation of the LFI mechanism remains difficult, but eventually can lead to success. By ‘trial-error-transcend,’ the City managed to build two essential roads while the developers received attractive investment opportunities in urban development. This mechanism cannot, however, be seen as a panacea for the local authorities due to constraints to replicate it and potential undesired ‘side effects.’     

Urban water capacity: Irrigation for heat mitigation

Our world has been continuously urbanized and is currently accommodating more than half of the human population. Despite that cities cover only <3% of the Earth's land surface area, they emerged as focal points of human activities, and confront numerous environmental challenges as a result of changes in landscapes, hydroclimate, ecosystems, and biodiversity. In particular, the built environment usually experiences exacerbated heat stress induced by global climate and landscape changes, commonly known as the urban heat island effect. Urban irrigation, as a climate adaptation and mitigation strategy, is effective in cooling the built environment, but exhibits large uncertainties in the trade-off between water use and heat mitigation capacity. Here we show the efficiency of cooling effect induced by irrigation of urban vegetation, represented by a novel metric, viz. urban water capacity, analogous to the heat capacity, across the contiguous United States (CONUS) during summertime via numerical simulations. The urban water capacity is calculated as the average irrigation depth per degree of urban temperature reduction; the values are 4.52 ± 0.77 mm day⁻¹ °C⁻¹ and 7.27 ± 1.27 mm day⁻¹ °C⁻¹ (mean ± standard deviation) for surface and near-surface air cooling, respectively, over the CONUS. The robustness of urban water capacity is further exemplified in an extreme heat wave event, during which the warming anomaly is partially offset by the additional cooling from urban irrigation. Estimates of water capacity provide a quantitative metric for evaluating the efficacy of irrigation in urban planning under current heat stress and future warming.     

An evolved VIKOR method for multiple-criteria compromise ranking modeling under T-spherical fuzzy uncertainty

The development of T-spherical fuzzy (T-SF) sets in qualitative multiple-criteria choice analysis has been well investigated, but little is explored about how the VIKOR (i.e., VIšekriterijumsko KOmpromisno Rangiranje in Serbian) mechanism is generalized into intricate T-SF environments. This paper has the objective of propounding a creative T-SF VIKOR methodology for compromise ranking modeling in multiple criteria analysis. The exploitation of the T-SF configuration brings about superior information space representation in response to intricate realistic environments. However, because of the increased complexity of decision situations involving T-spherical fuzziness, treatment with the T-SF information arises a pragmatic difficulty in developing methodological approaches to T-SF VIKOR. In light of this concern, this paper unfolds an analytical framework for the T-SF VIKOR method predicated on new notions of an evolved T-SF score function and the Minkowski-type T-SF distance measure along with its special cases of the Manhattan-, Euclidean-, and Chebyshev-type distances. The aspired and despised T-SF characteristics can be identified supported by the evolved T-SF score function of T-SF performance ratings. This paper gives a new delineation of the group utility, individual regret, and joint generalized measures with the aid of the Minkowski-type T-SF distance measure relative to the aspired/despised T-SF characteristics. A synthetic mechanism is built to validate the standards of acceptable advantage and stability and yield the ultimate compromise choices for multiple criteria decision aiding. The practicality of the T-SF VIKOR methodology in down-to-earth decision situations has been well demonstrated through the selection issues of warehouse locations and advertisement strategies. Moreover, the developed approach has shown better application outcomes than the past methods did. The comparative study with parametric analysis has revealed the steadiness and effectiveness of the compromise choice results in T-SF circumstances.     

Hierarchical learning using deep optimum-path forest

Bag-of-Visual Words (BoVW) and deep learning techniques have been widely used in several domains, which include computer-assisted medical diagnoses. In this work, we are interested in developing tools for the automatic identification of Parkinson’s disease using machine learning and the concept of BoVW. The proposed approach concerns a hierarchical-based learning technique to design visual dictionaries through the Deep Optimum-Path Forest classifier. The proposed method was evaluated in six datasets derived from data collected from individuals when performing handwriting exams. Experimental results showed the potential of the technique, with robust achievements.     

Urban form breeds neighborhood vibrancy: A case study using a GPS-based activity survey in suburban Beijing

In this paper, we present a formal analysis of the neighborhood vibrancy created by urban form. We use Geographic Information Systems (GIS) to develop quantitative measures of urban form and define neighborhood vibrancy based on a GPS-based activity survey in suburban Beijing. An Urban Form index was adopted to determine that our measures of urban form capture meaningful differences in the characteristics of urban neighborhoods – differences that may have direct impacts on neighborhood vibrancy. Specifically, high density and mixed land use are strongly positively correlated with neighborhood vibrancy, whereas developed external traffic systems are negative. However, a thorough inter-circulation system and convenient accessibility do not always boost neighborhood vibrancy. These factors lose efficacy when gated neighborhoods are selected and surrounding facilities are distributed far away. Our study argues that urban planners, using their professional judgment, can contribute to urban vitality at the neighborhood scale.