A novel way of texturing glass for microcrystalline silicon thin film solar cells application

In this paper, we present a novel way of texturing glass facilitated by ZnO:Al thin film as sacrificial layer for thin film silicon solar cell application. We name this technique zinc oxide‐induced texturing (ZIT). The texturing of glass was achieved by wet etching of ZnO:Al covered glass with HF and HNO₃ as etchants. We investigated the influence of the ZnO:Al layer sputtering condition, the layer thickness, and the etchant composition on the surface morphology of the textured glass. We demonstrate that we are able to control the roughness of the ZIT glass over a wide roughness range, ranging from 20 to 400 nm. Highly efficient microcrystalline silicon n‐i‐p solar cells were deposited on ZIT glass. The influence of the substrate morphology on the solar cell performance is also discussed. The highest efficiency for a single junction n‐i‐p microcrystalline silicon solar cell obtained in this work is 10.64% (Active area). Copyright © 2014 John Wiley & Sons, Ltd.     

Texturing of polycrystalline photovoltaic materials using vertically aligned carbon nanotube arrays

In order to demonstrate that three‐dimensional carbon nanotube‐based photovoltaic devices show an increase in power output over similar planar cells, we have produced cells with texturing through the use of vertically aligned carbon nanotube arrays and cells without this texturing. The output power of these cells at varying incident angles of light was measured. The textured cells show an increase in the normalized power output compared with similar planar cells when the solar flux is at off‐normal angles. The power output versus incident angle curve takes an inverted C‐type curve as predicted by the theory developed previously, with very good agreement between experimental results and theoretical predictions. Copyright © 2012 John Wiley & Sons, Ltd.     

Rapid prototyping of geosynthetic interfaces: Investigation of peak strength using direct shear tests

Rapid prototyping offers a platform technology for investigations within the geosynthetics research and manufacturing sectors. This paper considers the application of rapid prototyping for the development of geosynthetic interfaces. The benefits and challenges of three rapid prototyping techniques (fused filament fabrication, selective laser sintering and laser thermal ablation) are considered and comparisons are presented between the three technologies. The paper then compares prototyped models of geomembrane texturing to those of a factory sourced reference geomembrane, leading on to a systematic geometric assessment using laser sintered model geomembranes. The geometric assessment highlights the benefits of hooked geomembrane asperities to interact with geotextiles in low normal stress applications, with a 69% increase in peak shear strength reported for hooked asperities, compared to the factory reference geometry. Asperity spacing is shown to influence the measured shear strength, with an increase for a geomembrane geotextile interfaces with closer asperities and an optimum spacing observed for geomembrane clay interfaces, below which the failure plane slides over the top of the texturing. Increases in asperity height correlated to smaller than expected increases in shear stresses for both geomembrane-geotextile and geomembrane clay interfaces.Whilst current rapid manufacturing techniques are shown to offer the ability to test the influence of variables on the performance characteristics of geosynthetic materials, the limitations of each technique, polymer utilised and resulting chemical and physical behaviour of the sample must be understood to allow these techniques to be successfully deployed.     

变形纱成纱熵变对条干均匀度的影响

长丝变形纱在变形加工过程中,其成纱熵变是增加的。成纱熵变是状态函数,其与变形纱紊乱度的对数成正比,因此成纱熵变对变形纱的表观条干均匀度有显著影响。随着成纱熵变和紊乱度不断增加,变形纱的外观和性能均发生明显改变,其表观CV值迅速增加,并接近短纤维纱条干CV值,仿短纤维纱化效果明显。这种状况可通过长丝变形纱表观直径变化总频数及频率分布加以表现。由膨松结构引起的空气变形纱表观条干均匀度值的异常改变使其与质量条干均匀度值不相关,这是变形纱区别于传统短纤维纱的主要特征之一。     

轧辊表面光纤激光毛化工艺研究

利用光纤激光柔性工作站对轧辊表面进行毛化,研究了激光射出头姿态、侧吹角对毛化点形貌、毛化后轧辊表面粗糙度的影响,分析了其影响规律,总结出最佳毛化工艺.结果表明,12点位置和3点位置在特定侧吹角度时,毛化点分布相对独立,凸台金属分布集中,无点与点搭接现象,毛化点形貌满足要求.12点位置和9点位置各侧吹角度下的毛化表面粗糙度均满足要求.综合对毛化点形貌和毛化后轧辊表面粗糙度要求,12点位置的毛化效果优于3点位置.研究结果已应用于实际生产.     

Effect of nozzle size on texturing performance: comparison between air-jet and steam-jet texturing

The objectives of this research work were to investigate the use of steam in order to replace air in the production of spun-like textured yarn and to investigate the optimum nozzle size for steam-jet textured yarn for the application of sewing thread. An existing air-jet texturing machine was modified to supply either air or steam to the texturing nozzle. Using four texturing nozzles, both air-jet and steam-jet textured yarns were manufactured. The effect of nozzle size on process and yarn parameters has been studied and compared with air-jet textured yarns. The results show that spun-like textured yarn manufactured using steam has lower loop instability and higher tensile properties than air at comparable fluid pressures. SEM image analysis shows that the entangled structure of the steam-jet textured yarns is similar to air-jet textured yarns. Further, sewability results show that steam-jet textured yarns are suitable to manufacture sewing threads.     

VC473等弹力丝假捻机卷绕机构的运动分析及其设计

对ＶＣ４７３等弹力丝假捻机卷绕机构进行了运动分析，将导得的方程用计算机进行了计算。论证了该机构工作可靠、运转平稳、结构合理。探讨了该机构主要设计参数的选择对运动的影响。     

Constructive texturing based on hypervolume modeling

The concept of solid texturing is extended in two directions: constructive modeling of space partitions for texturing and modeling of multidimensional textured objects called hypervolumes. A hypervolume is considered as a point set with attributes of both physical (density, temperature, etc.) and photometric (color, transparency, diffuse and specular reflections, etc.) nature. The point set geometry and attributes are modeled independently using real‐valued scalar functions of several variables. Each real‐valued function defining geometry or an attribute is evaluated at the given point by a procedure traversing a constructive tree structure with primitives in the leaves and operations in the nodes of the tree. This approach provides a framework for modeling, texturing and visualization of 3D solids, time‐dependent and multidimensional objects in a completely uniform manner. We introduced a special modeling language and implemented software tools supporting the proposed approach. The concept of constructive hypervolume textures is independent of the geometry representation. We provide examples of textured Frep and BRep objects as illustrations. Copyright © 2002 John Wiley & Sons, Ltd.     

局部织构无限长可倾瓦推力轴承流体动压润滑分析

目的 研究局部凹坑织构对无限长可倾瓦推力轴承的流体动压润滑性能的影响.方法 基于质量守恒空化边界条件的雷诺方程,建立了局部凹坑织构无限长可倾瓦推力轴承动压润滑二维理论模型.采用多重网格法求解雷诺方程,模拟局部凹坑织构无限长可倾瓦推力轴承的流体动压分布,分析局部织构比、位置比、深度、水平间距及数量对流体动压润滑性能的影响...