Use of epoxy as an adhesive is a common practice. The most common applications are permanent sealants. Epoxies have a wide range of operating temperatures, and are very resistance to adhesive failure. When a need to r...Use of epoxy as an adhesive is a common practice. The most common applications are permanent sealants. Epoxies have a wide range of operating temperatures, and are very resistance to adhesive failure. When a need to remove this adhesive arises, it is not always easily accomplished especially if the part has excessive adhesive. To maintain fidelity of the parts attached by epoxy, a project evaluating several methods of epoxy removal was conducted. Methods evaluated included low wavelength, near-ultraviolet radiation, solvent dissolution, and thermal cycling. The UV method failed to demonstrate a repeatable dissociation. The solvent study did result in dissociation of bonds, but introduced chemicals that could make subsequent chemical analysis of parts suspect. Thermal cycling showed a high repeatability for dissociation of bonds and may prove to be relatively inexpensive to implement.展开更多
A proteinase responsible for degradation of yolk proteins has been discovered in oocyte of Antheraea pernyi which was found to found to hydrolyze vitelluin effectively in acidic pH. Using bovine hemoglobin as substrat...A proteinase responsible for degradation of yolk proteins has been discovered in oocyte of Antheraea pernyi which was found to found to hydrolyze vitelluin effectively in acidic pH. Using bovine hemoglobin as substrate,the optimum pH was determine3d at 3.5.Unaffected by EDTA and DipF, the activity of the proteinase was strongly inhibited by E64 and other thiol blocking reagents. It is thus very likely to be a cysteine proteinase. Activity of the proteinas. was found to be increasing in developing oocyte.展开更多
文摘Use of epoxy as an adhesive is a common practice. The most common applications are permanent sealants. Epoxies have a wide range of operating temperatures, and are very resistance to adhesive failure. When a need to remove this adhesive arises, it is not always easily accomplished especially if the part has excessive adhesive. To maintain fidelity of the parts attached by epoxy, a project evaluating several methods of epoxy removal was conducted. Methods evaluated included low wavelength, near-ultraviolet radiation, solvent dissolution, and thermal cycling. The UV method failed to demonstrate a repeatable dissociation. The solvent study did result in dissociation of bonds, but introduced chemicals that could make subsequent chemical analysis of parts suspect. Thermal cycling showed a high repeatability for dissociation of bonds and may prove to be relatively inexpensive to implement.
文摘A proteinase responsible for degradation of yolk proteins has been discovered in oocyte of Antheraea pernyi which was found to found to hydrolyze vitelluin effectively in acidic pH. Using bovine hemoglobin as substrate,the optimum pH was determine3d at 3.5.Unaffected by EDTA and DipF, the activity of the proteinase was strongly inhibited by E64 and other thiol blocking reagents. It is thus very likely to be a cysteine proteinase. Activity of the proteinas. was found to be increasing in developing oocyte.
