987 resultados para GLASS BEAD TECHNOLOGY
Resumo:
Linkam CSS450 optical shearing stage, wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering(SAXS) were used to investigate the effect of shear on crystal structure and crystallization morphology of the glass bead filled polypropylene( PP). The results indicate that the glass bead worked as nucleating agent for the glass bead filled PP, compared with pure PP it restrained the formation of beta-crystal after shear treatment. When the mean size of glass bead is smaller(4 mu m) shear rate had less effect on the formation of beta-crystal of PP obviously.
Resumo:
Notch Izod impact strength of poly(propylene) (PP)/glass bead blends was studied as a function of temperature. The results indicated that the toughness for various blends could undergo a brittle-ductile transition (BDT) with increasing temperature. The BDT temperature (T-BD) decreased with increasing glass bead content. Introducing the interparticle distance (ID) concept into the study, it was found that the critical interparticle distance (IDc) reduced with increasing test temperature correspondingly. The static tensile tests showed that the Young's modulus of the blends decreased slightly first and thereafter increased with increasing glass bead content. However, the yield stress decreased considerably with the increase in glass bead content. Dynamic mechanical analysis (DMA) measurements revealed that the heat-deflection temperature of the PP could be much improved by the incorporation of glass beads. Moreover, the glass transition temperature (T-g) increased obviously with increasing glass beads content. Differential scanning calorimetry (DSC) results implied that the addition of glass beads could change the crystallinity as well as the melting temperature of the PP slightly.
Resumo:
The mechanical and thermal properties of glass bead-filled nylon-6 were studied by dynamic mechanical analysis (DMA), tensile testing, Izod impact, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) tests. DMA results showed that the incorporation of glass beads could lead to a substantial increase of the glass-transition temperature (T-g) of the blend, indicating that there existed strong interaction between glass beads and the nylon-6 matrix. Results of further calculation revealed that the average interaction between glass beads and the nylon-6 matrix deceased with increasing glass bead content as a result of the coalescence of glass beads. This conclusion was supported by SEM observations. Impact testing revealed that the notch Izod impact strength of nylon-6/glass bead blends substantially decreased with increasing glass bead content. Moreover, static tensile measurements implied that the Young's modulus of the nylon-6/glass bead blends increased considerably, whereas the tensile strength clearly decreased with increasing glass bead content.
Resumo:
The effects of crystallization temperature (T,), glass bead content and its size on the, formation of beta-crystal and structural stability of originally formed beta-crystal in glass bead filled polypropylene (PP) were examined. The differential scanning calorimetry (DSC) measurements indicated that the amount of beta-phase in PP crystals was a function of the crystallization temperature and glass bead content. For a constant crystallization temperature, it was observed that the amount of beta-crystal initially increased with increase in glass bead content up to 30 wt.%, and then decreased slightly with further increase in the filler content. From the DSC data, a disorder parameter (S) was derived to define the structural stability of originally formed beta-crystals. The structural stability of originally formed beta-crystals was enhanced with increase in either the crystallization temperature or the glass bead content. Also, the influence of glass bead size (4-66 mu m) on the formation and stability of beta-crystals in PP/glass bead blends was studied. Large glass bead particles suppressed the formation and decreased the stability of beta-crystals.
Resumo:
The effects of the glass-bead content and size on the nonisothermal crystallization behavior of polypropylene (PP)/glass-bead blends were studied with differential scanning calorimetry. The degree of crystallinity decreased with the addition of glass bead, and the crystallization temperature of the blends was marginally higher than that of pure PP at various cooling rates. Furthermore, the half-time for crystallization decreased with an increase in the glass-bead content or particle size, implying the nucleating role of the glass beads. The nonisothermal crystallization data were analyzed with the methods of Avrami, Ozawa, and Mo. The validity of various kinetic models for the nonisothermal crystallization process of PP/glass-bead blends was examined. The approach developed by Mo successfully described the nonisothermal crystallization behavior of PP and PP/glass-bead blends. Finally, the activation energy for the nonisothermal crystallization of pure PP and PP/glass-bead blends based on the Kissinger method was evaluated.
Resumo:
The toughness of high-density polyethylene (HDPE)/glass-bead blends containing various glass-bead contents as a function of temperature was studied. The toughness of the blends was determined from the notch Izod impact test. A sharp brittle-ductile transition was observed in impact strength-interparticle distance (ID) curves at various temperatures. The brittle-ductile transition of HDPE/glass-bead blends occurred either with reduced ID or with increased temperature. The results indicated that the brittle-ductile-transition temperature dropped markedly with increasing glass-bead content. Moreover, the correlation between the critical interparticle distance (ID.) and temperature was obtained. Similar to the ID, of polymer blends with elastomers, the ID, nonlinearly increased with increasing temperature. However, this was the first observation of the variation of the ID, with temperature for polymer blends with rigid particles. (C) 2001 John Wiley & Sons, Inc. J Polym. Sci Part B: Polym. Phys 39: 1855-1859, 2001.
Resumo:
Genetic transformation by electroporation of protoplasts is a standard procedure for many plants. However, for the genus Porphyra, the method is not effective because of low viability of protoplasts and is a time-consuming and expensive procedure. Based on the life history of Porphyra, a spore-targeted strategy of genetic transformation was developed, that is, using fresh conchospores of Porphyra haitanensis Chang & Zheng transformed by agitation with glass beads. A SV40 promoter-driven lacZ reporter gene was expressed in conchospores 48 h after the agitation. More transformants were obtained by increasing the agitation time from 10 to 25 s. The maximum number of transformants was more than six out of 1 million agitated conchospores. Transfer of a SV40 promoter-driven egfp gene into conchospores resulted in significant green GFP fluorescence. The expression of lacZ and egfp revealed that this strategy of spore-targeted transformation using glass bead agitation is feasible in P. haitanensis and that the SV40 promoter is effective for monitoring expression of foreign genes in this red algal species.
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Supported liquid phase catalyst (SLPC) is one of effectively heterogenized homogeneous catalysts using organometallic complexes as active components, which are dissolved in a small quantity of liquid phase dispersed in the form of isle or film on the surface of supports. The SLPC has successfully been applied for several chemical transformations and this article will review recent results with respect to the preparation and catalytic performance, the applicability to continuous flow operations, and the capability of multifunctional catalysis.
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This paper presents a participatory project involving the traditional glass bead craft industries in rural Java, Indonesia. Their survival is in danger due to tight business competition among themselves and due to shortcomings in existing business mechanisms. The research explores a departure from traditional government assistance programs which seek to train craftspeople with new kinds of technology based skills. Instead, the project explores alternate business mechanisms, ways for traditional craftspeople to get more power in business mechanisms, and ways to develop new design strategies through a collaborative approach. The ultimate goal is to ensure sustainable livelihoods for traditional craft producers and for the traditional craft industry in general. This research also aims to support the economic strength and competitiveness of these industries indirectly by i. Generating knowledge about developing innovation strategies in the traditional craft industry; ii. Providing an alternative advisory program to support the sustainability of the traditional souvenir craft industry; iii. Providing inputs for designers or any institutions who intend to establish collaborative design learning with craft industries. Understanding the situation carefully,including sensitivities such as culture and tensions among people, building self-confidence and trust among craftspeople as well as involving junior designers are keys in pursuing a participatory project in this case.
Resumo:
This paper examines the role of actors in a participatory project, a case study of the glass-bead traditional craft industry in rural Indonesia. The project aimed to unite and empower rural craftspeople with regard to their unique potential. The problems of empowering rural craftspeople were complicated, due to the interrelated aspect of rural community life, cultural and educational backgrounds, as well as the local political situation. However, through a comprehensive understanding of the community prior to the project and by maintaining the communication, craftspeople were engaged actively in the project by promoting the craft industry to local buyers. The researcher, other facilitators and the community leader gave supportive roles at the middle and the end stage of the project.
Resumo:
This paper presents a case study of the participatory project in the Jombang glass bead craft industry. Economic instability has brought significant business challenges in the community. The involvement of outsiders to collaborate with craftspeople in order to support business innovation as well as strengthen the social capital in the community is essential. However, facilitating a rural community to formulate and implement bottom-up planning needs an integrated approach. In this paper, we explain a participatory project in the rural craftspeople community that resulted in a collective action. The project aimed at uniting and empowering rural craftspeople focusing on the unique skills and knowledge of participants. There are some aspects influencing the success of collective action: the ability to understand the local political situation; the role of facilitators to respect and support the unique potential of craftspeople; and the economic benefit of the program.
Resumo:
The research explores the potential for participatory and collaborative approaches in working with the Indonesian glass-bead rural craft industry, which currently struggles to sustain its business. Contextual inquiry and participatory action research were used to understand the local context, including motivations, barriers and opportunities and to collaboratively develop strategies for advancement and innovation. The study documents participatory design projects undertaken to make, sell and promote hedonic products. It identifies the importance of understanding local context and individual craftsperson aspirations in designing collaborative support programs. It also provides an in depth insight into the Indonesian rural craft industry.