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Photopolymerizable liquid encapsulants (PLEs) for microelectronic devices may offer important advantages over traditional transfer molding compounds, including reduced in‐mold cure times, lower thermal stresses, and reduced wire sweep. In this contribution, we discuss an encapsulation process based upon a low viscosity resin that cures rapidly upon exposure to UV light. These highly filled PLEs are comprised of an epoxy novolac‐based vinyl ester resin (~25 wt %), fused silica filler (70–74 wt %), photoinitiator, silane coupling agent, and, in some cases, a thermal initiator. We have characterized the material properties (flexural strength and modulus, coefficient of thermal expansion, glass transition temperature, and thermal stress parameter) of PLEs cured with UV illumination times of 60, 90, and 120 s, as well as, the thermal conductivity and adhesive peel strength of PLEs photocured for 90 s. In addition, we investigated the effect of the fused silica loading and the initiation scheme on these properties. The results indicate that the PLEs are very promising for microelectronic encapsulation. These liquid encapsulants cure (to an ejectable hardness) in 1 min for an initiating light intensity of 200 mW/cm2, and exhibit appropriate values for the thermal and mechanical properties listed above. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3449–3461, 2001 相似文献
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Effect of ozonation and ultrasonication pretreatment processes on co-digestion of tannery solid wastes 总被引:1,自引:1,他引:0
K. Sri Bala Kameswari Chitra Kalyanaraman K. Thanasekaran 《Clean Technologies and Environmental Policy》2011,13(3):517-525
Studies were carried out by the application of ozonation and ultrasonication as pretreatment processes on primary and secondary
sludge generated during treatment of tannery wastewater to enhance the soluble chemical oxygen demand (SCOD). Further, co-digestion
(simultaneous digestion of two or more substrates) studies were carried out in batch reactors using the fleshings (a solid
waste generated during the processing of raw hides or skins into finished leather) along with the primary and the secondary
sludge wherein biogas generation was compared with and without pre-treated sludge using ozone and ultrasonication processes,
respectively. It was found that, application of pretreatment processes enhanced biogas generation by 45% in the case of ozone
pre-treated sludge and 53% by ultrasonication processes, respectively, in conjunction with the fleshings. However, considering
the optimum contact time required, application of ultrasonication as a pretreatment process was found to be the most appropriate
and viable process to enhance the SCOD. This pretreatment process has the potential for implementation in tanneries using
the shortest possible ultrasonication time to minimize energy cost when compared with ozonation time. 相似文献
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Permeable pavement systems (PPS) are frequently associated with high removal efficiencies for water quality parameters. Their effluent can, therefore, be recycled, for example, for sprinkling onto gardens. Nevertheless, some stakeholders fear that potentially pathogenic organisms within the treated run‐off could be too high, and therefore they request disinfection before recycling. The aim of this paper is, therefore, to assess the efficiency of a batch flow combined titanium dioxide (TiO2) and ultraviolet (UV) light photocatalytic reactor in removing water‐borne microbial contaminants from the effluent of PPS. Combined TiO2 and UV photocatalytic reaction times between 80 and 100 min were required for the complete removal of Escherichia coli, total coliforms and faecal Streptococci, which had mean initial counts of 1.5 × 107, 4.4 × 106 and 6.9 × 105 colony‐forming units (CFU) per 100 mL, respectively. In comparison, UV disinfection alone resulted in insignificant microbial removal. Suspended TiO2 powder was more effective than small immobilised TiO2 crystals. 相似文献
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The Change of X‐ray Diffraction Peak Width During in situ Conventional Sintering of Nanoscale Powders
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Jean‐Marie Lebrun Shikhar K. Jha Kiran S. Naik Kevin C. Seymour Waltraud M. Kriven Rishi Raj 《Journal of the American Ceramic Society》2016,99(3):765-768
Diffraction peaks of nanoscale particles of 3 mol% yttria‐stabilized zirconia become sharper as the powder sinters. The reduction in the peak width is correlated with the increase in density. The sharpening of the peak agrees reasonably well with the remaining free surface area as the sample sinters. Therefore, high curvature of the free surface of the pores is assumed to lead to peak broadening (the grain boundaries that grow at the expense of the free surfaces of the pores do not have this curvature). The change in the grain size during sintering does not make a significant contribution to peak width. 相似文献
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Han Liuyang Zhang Saisai Zhang Bowen Zhang Bo Hari Bala Zhang Zhanying 《Journal of Porous Materials》2022,29(1):269-278
Journal of Porous Materials - Aimed at detecting methane (CH4) gas at low operating temperature, porous ZnO/SnO2 nanocomposites were constructed through a simple two-step method. Pure SnO2 with a... 相似文献
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