New friction welding process for pipeline girth welds—welding time optimisation

CAD/CAM systems are the important interface for automating manufacturing processes to accommodate the varying market demands. However, they are often operated in an isolated environment and are unable to communicate with each other. Rapid development and enhancement of the network technology had made it possible for manufacturing processes to be implemented in a distributed environment. The purpose of this study is to develop a dispersed networked multi-axis surface manufacturing system. The proposed research uses the Integrated Definition for Function Modelling (IDEF0) methodology to analyze the manufacturing activities and adopts the Common Object Request Broker Architecture (CORBA) standard as the infrastructure of software components. Using IDEF0, the manufacturing activities can be analyzed and represented as a hierarchical and structural functional model. The developed system has the “plug-and-play” capability and can be integrated with other development teams to achieve information sharing. On-line test of the prototype system has been implemented collaboratively by three development teams and the effectiveness of the developed system has also been confirmed. The developed system has successfully integrated resources of different locations through a network and can effectively reduce the product development and manufacturing time, thus enhancing the global competitiveness of the industry.     

The effect of hyaluronan combined with KI3 complex (Hyiodine wound dressing) on keratinocytes and immune cells

Hyiodine (high molecular weight hyaluronan combined with KI₃ complex) is a new non-adhesive wound dressing which significantly improves the healing process. The aim of the study was to investigate the effects of Hyoidine on functional properties of isolated human keratinocytes and leukocytes, and on those of U937 and HL60 cell lines. While KI₃ complex inhibited the viability and proliferation of the cells tested, Hyiodine did not have any significant effect. The expression of CD11b, CD62L and CD69 on PMNL, monocytes and lymphocytes, as well as the oxidative burst of blood neutrophils, were not changed. On the contrary, Hyiodine inhibited the PMA-activated oxidative burst and significantly increased the production of IL-6 and TNF-α by lymphocytes. It was concluded that hyaluronan content of Hyiodine reduces the toxic effect of KI₃ complex on cells and speeds up the wound healing process by increasing the production of inflammatory cytokines.     

Three-dimensional microstructural changes in the Ni–YSZ solid oxide fuel cell anode during operation

Microstructural evolution in solid oxide fuel cell (SOFC) cermet anodes has been investigated using X-ray nanotomography along with differential absorption imaging. SOFC anode supports composed of Ni and yttria-stabilized zirconia (YSZ) were subjected to extended operation and selected regions were imaged using a transmission X-ray microscope. X-ray nanotomography provides unique insight into microstructure changes of all three phases (Ni, YSZ, pore) in three spatial dimensions, and its relation to performance degradation. Statistically significant 3D microstructural changes were observed in the anode Ni phase over a range of operational times, including phase size growth and changes in connectivity, interfacial contact area and contiguous triple-phase boundary length. These observations support microstructural evolution correlated to SOFC performance. We find that Ni coarsening is driven by particle curvature as indicated by the dihedral angles between the Ni, YSZ and pore phases, and hypothesize that growth occurs primarily by means of diffusion and particle agglomeration constrained by a pinning mechanism related to the YSZ phase. The decrease in Ni phase size after extended periods of time may be the result of a second process connected to a mobility-induced decrease in the YSZ phase size or non-uniform curvature resulting in a net decrease in Ni phase size.     

Design of experiment approach applied to reducing and oxidizing tolerance of anode supported solid oxide fuel cell. Part II: Electrical, electrochemical and microstructural characterization of tape-cast cells

One of the major limitations of the nickel (Ni) - yttria-stabilized zirconia (YSZ) anode support for solid oxide fuel cells (SOFC) is its low capability to withstand transients between reducing and oxidizing atmospheres (“RedOx” cycle), owing to the Ni-to-NiO volume expansion. This work presents results on different anode supports fabricated by tape casting. Three compositions are prepared, as the outcome of a preceding design of experiment approach. The NiO proportion is 40, 50 and 60 wt% of the anode composite.The anode support characteristics like shrinkage during sintering, in-situ conductivity at high temperature, electrochemical performance and tolerance against RedOx cycles have been measured. Performance up to 0.72 W cm⁻² (0.62 V, 800 °C) is recorded for the 60 wt% NiO sample on small cells. The open circuit voltage is maintained within ±5 mV after 10 full RedOx cycles at 800 °C and one at 850 °C. Performances tend to be stabilized after one or multiple RedOx cycles. The microstructural observations show round Ni particles after the first reduction; after a RedOx cycle, the Ni particles include micro-porosities that are stable under humidified reducing atmosphere for more than 300 h.     

Wrinkle free plaited knitted fabrics without pre-heat setting

Wrinkle free fabric at low cost is always a desirable aesthetic property. Different type of resins/finishes and pre-heat setting prior to processing are applied to avoid wrinkles in woven and hosiery, respectively. Current study is proposed to produce wrinkle free circular plaited knitted fabric by the elimination of a pre-boarding step. In this achievement, yarn covering parameters and compatibility of yarns with knitting machines are examined. Sock samples were analyzed for improved physical appearance (wrinkles) after various processes (pre-tumbling, dyeing, bleaching, and washing). Yarn specifications (sheath yarn fineness, sheath yarn texture i.e. shrink/un-shrink, covering air-knots) impact on socks physical appearance were also analyzed. The results clearly showed that by decreasing number of yarn covering air knots and sheath yarn fineness leads to prevention of wrinkle formation. The results also prove to be supportive for cost effectiveness by eliminating the pre-setting stage.     

On the crystallographic anisotropy of nanoindentation in pseudoelastic NiTi

We use a nanoindenter with a Berkovich tip to study local mechanical properties of two polycrystalline intermetallics with a B2 crystal structure, NiAl and NiTi. We use orientation imaging scanning electron microscopy to select a relevant number of grains with appropriate sizes and surface normals parallel to 〈0 0 1〉, 〈1 0 1〉 and 〈1 1 1〉. As a striking new result, we find a strong crystallographic orientation dependence for NiTi. This anisotropy is less pronounced in the case of NiAl. For NiTi, the indentation force required to impose a specific indentation depth is highest for indentation experiments performed in the 〈0 0 1〉 direction and lowest along the 〈1 1 1〉 direction. We consider transmission electron microscopy results from cross-sections below the indents and use molecular dynamics simulations and resolved shear stress calculations to discuss how this difference can be accounted for in terms of elementary deformation and transformation processes, related to dislocation plasticity (NiAl and NiTi), and in terms of the stress-induced formation and growth of martensite (NiTi). Our results show that the crystallographic anisotropy during nanoindentation of NiTi is governed by the orientation dependence of the martensitic transformation; dislocation plasticity appears to be less important.     

Data-driven and tool-supported elicitation of quality requirements in agile companies

Software Quality Journal - Quality requirements (QRs) are a key artifact needed to ensure the quality and success of a software system. Despite their importance, QRs rarely get the same degree of...     

Continuous Matching via Vector Field Flow

We present a new method for non‐rigid shape matching designed to enforce continuity of the resulting correspondence. Our method is based on the recently proposed functional map representation, which allows efficient manipulation and inference but often fails to provide a continuous point‐to‐point mapping. We address this problem by exploiting the connection between the operator representation of mappings and flows of vector fields. In particular, starting from an arbitrary continuous map between two surfaces we find an optimal flow that makes the final correspondence operator as close as possible to the initial functional map. Our method also helps to address the symmetric ambiguity problem inherent in many intrinsic correspondence methods when matching symmetric shapes. We provide practical and theoretical results showing that our method can be used to obtain an orientation preserving or reversing map starting from a functional map that represents the mixture of the two. We also show how this method can be used to improve the quality of maps produced by existing shape matching methods, and compare the resulting map's continuity with results obtained by other operator‐based techniques.