Advanced Materials Research Vols. 476-478

Abstract: The akund fiber has great potential to be used in the textile industry benefiting from its excellent properties. The adoption of akund fiber from calotropis gigantea could substitute or supplement cotton as raw materials for textile fabric and might reduce the possible damage to the environment. Therefore, The study in this paper on the relationship between carding procedure and the quality of akund fiber sliver aimed at optimizing the process of this new kind fiber on a flat top card has significant meaning. The results in this paper show that high quality slivers can be produced by using new wires, low speed of card elements or proper akund fiber content in blended yarn. However, decreasing the number of moving flats in the main carding zone too much would deteriorate the sliver quality.

Abstract: Job shop scheduling belongs to the large class of NP-complete (nondeterministic polynomial time complete) problems and the complexity of job shop scheduling characterizes many real-life situations. In auto blanking plant, intelligent scheduling system is needed to deal with the automation of production. The core structure of job shop scheduling system is designed. The scheduling rules such as mission-critical priority rule, first come first serve rule, the highest task priority rule and the urgent tasks priority rule are built with the definitions of express tasks, urgent tasks, middle urgent tasks and normal tasks according to the time features of tasks. The heuristic optimization algorithm is designed to follow the above rules. The intelligent logistics management system is built to optimize job shop scheduling in auto blanking plant.

Abstract: According to the space surface positioning principle, in this paper, to the practical need for clamping of the thin-walled curved surface parts as the background, the principles and methods of the production of flexible positioning surface are studied and a flexible clamping fixture is designed. It also elaborated the general flow of deformation analysis to the gripping parts with ANSYS. In addition, it analyzed the gripping deformation of the known surface parts, and validated the deformation index of the clamping fixtures.

Abstract: This paper describes in detail a Web-based, browser-server architecture specifically designed to allow live data transmission and a flexible management of remote instruments. The DataSocket and Java applet developed using the DataSocket JavaBean are used to stream live data from the instrument to remote clients. Remote monitoring is developed by the employment of the TCP/IP protocol suite and Java applet, and the results can be displayed by general web browser. This approach shows an effective and a feasible way for applications development for remote monitoring.

Abstract: 3 specimens of full-scale reinforced concrete columns were tested under monotonic axial loading, in which the hoop configuration of one specimen was #, and the other two used the two-directional composite spiral hoops. The axial compressive performances of full-scale reinforced concrete columns confined by different configurations and strengths of hoops were discussed. One of the columns confined by spiral hoops used high-strength steels with the yield strength of 1000MPa as hoops, while the other two columns used ordinary-strength steel with yield strength of 400MPa. Columns confined by spiral hoops exhibited slight higher bearing capacity and better deformation ability than columns with hoop configuration #. The results also indicated that compared with the specimen used ordinary-strength hoops, the bearing capacity of the specimen used high-strength hoops was basically the same, but the deformation ability improved obviously.

Abstract: Generally the process of hull part cutting is that the part can not be cut until the previous part has been cut. This mode is poor cutting efficiency and high cutting cost. Based on the famous Seven Bridges Problems, this paper models the cutting problem and then presents a brand-new cutting technology, the bridge cutting. In this technology, only one pierce point is enough to cut off all the parts that lie in the same level. The example shows that the technology is effective for reducing the numbers of pierce points and shortening the length of idle cutting path, which not only improves the cutting efficiency but also saves the cutting cost.

Abstract: Escherichia coli W produces a mixture of organic acids during fermentation in mineral salts medium using glucose as the sole carbon source. Among these products, D-lactate, acetate, succinate, and ethanol are the majors, with formate as a minor. In order to evaluate the effect of adhE mutation on the metabolism for D-lactic acid production by E. coli W, an adhE deletion mutant JH11 was constructed using the RED recombination system and the flipase recognition target （FRT） site-specific recombinant technology. Compared to the parent strain, JH11 produced significantly higher concentration of D-lactate due to the increased NADH availability, with slightly changed acetate (increased), and succinate (decreased), in fermentations using mineral salts medium containing glucose as the carbon source and calcium carbonate as the neutralizer.

Abstract: In this study, a genipin cross linked scaffold containing nano-hydroxyapatite (n-HAp) and carboxymehthyl chitosan (CMCS) was developed by freeze drying technique. The scaffolds were characterized using FTIR, XRD and SEM. The cytotoxicity of the scaffolds was compared with scaffolds cross linked by glutaraldehyde, and the Young’s modulus was also tested. FTIR and XRD results indicated that CMCS’s hydroxyl group, amino and amide regulated the n-HAp crystallization process, which results in the nano homogenous distribution of n-HAp and provided nano topographical features for nanohybrid scaffolds. SEM images revealed the scaffolds had porous structure and the pores were interconnected with an average diameter of 150 μm, which was profit for the growth of tissues. Cell morphology showed the genipin cross linked scaffolds had less toxicity and more facility for adhesion and proliferation of cells. Great mechanical properties of the scaffolds indicate their potential use in bone tissue engineering.

Abstract: Tributyl borate was first adopted for the introduction of boron in the preparation of bioactive borosilicate xerogel by sol-gel method. The xerogel reacted continuously in 0.25M K2HPO4 solution with a starting pH value of 7.0 at 37 °C for 1day. The structural, morphologies and compositional changes resulting from the conversion were characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The results indicated that speed of formation of HA was cut way back on the time with the addition of boron and the induction period for the HA nucleation on the surface of the borosilicate xerogel was short than 1 days. The conversion mechanism of the borosilicate xerogels to hydroxyapaptite was also discussed.

Abstract: Porous tantalum; biomaterials; bone ingrowth; laser cladding; Abstract. Porous tantalum, a new low modulus metal with a characteristic appearance similar to cancellous/trabecular bone, is currently available for use in several orthopedic applications (hip and knee arthroplasty, spine surgery, and bone graft substitute). The open-cell structure of repeating dodecahedrons is produced via carbon vapor deposition/infiltration of commercially pure tantalum onto a vitreous carbon scaffolding. This transition metal maintains several interesting biomaterial properties, including: a high volumetric porosity (70-80%), low modulus of elasticity (3MPa), and high frictional characteristics. Tantalum has excellent biocompatibility and is safe to use in vivo as evidenced by its historical and current use in pacemaker electrodes, cranioplasty plates and as radiopaque markers. The bioactivity and biocompatibility of porous tantalum stems from its ability to form a self-passivating surface oxide layer. This surface layer leads to the formation of a bone-like apatite coating in vivo and affords excellent bone and fibrous in-growth properties allowing for rapid and substantial bone and soft tissue attachment. Tantalum-chondrocyte composites have yielded successful early results in vitro and may afford an option for joint resurfacing in the future. The development of porous tantalum is in its early stages of evolution and the following represents a review of its biomaterial properties and fabrication methods for applications as implant biomaterials.