AIM： To introduce and evaluate the efficacy and technical aspects of endoscopic submucosal dissection （ESD） using a novel device, the Fork knife. METHODS： From March 2004 to April 2008, ESD was performed on 265 ga...AIM： To introduce and evaluate the efficacy and technical aspects of endoscopic submucosal dissection （ESD） using a novel device, the Fork knife. METHODS： From March 2004 to April 2008, ESD was performed on 265 gastric lesions using a Fork knife （Endo FS） （group A） and on 72 gastric lesions using a Flexknife （group B） at a single tertiary referral center. We retrospectively compared the endoscopic characteristics of the tumors, pathological findings, and sizes of the resected specimens. We also compared the en b/oc resection rate, complete resection rate, complications, and procedure time between the two groups. RESULTS： The mean size of the resected specimens was 4.27 ± 1.26 cm in group A and 4.29 ± 1.48 cm in group B. The en b/oc resection rate was 95.8% （254/265 lesions） in group A and 93.1% （67/72） in group B. Complete ESD without tumor cell invasion of the resected margin was obtained in 81.1% （215/265） of group A and in 73.6% （53/72） of group B. The perforation rate was 0.8% （2/265） in group A and 1.4% （1/72） in group B. The mean procedure time was 59.63 ± 56.12 min in group A and 76.65 ± 70.75 min in group B （P 〈 0.05）. CONCLUSION： The Fork knife （Endo FS） is useful for clinical practice and has the advantage of reducing the procedure time.展开更多
Cutting parameters were evaluated and optimized based on multiple performance characteristics including tool wear and size error of drilled hole. Taguchi＇s L27, 3-level, 4-factor orthogonal array was used for the tes...Cutting parameters were evaluated and optimized based on multiple performance characteristics including tool wear and size error of drilled hole. Taguchi＇s L27, 3-level, 4-factor orthogonal array was used for the tests. It is shown that generally abrasive wear and built up edge （BUE） formation were seen in the tool wear, and the comer wear was also of major importance. Flank wear of the cutting tool was found to be mostly dependent upon particle mass fraction, followed by feed rate, drill hardness and spindle speed, respectively. Among the tools used, TiAlN coated carbide drills showed the best performance with regard to the tool wear as well as hole size. Grey relational analysis indicated that drill material was the more influential parameter than feed rate and spindle speed. The results revealed that optimal combination of the drilling parameters could be used to obtain both minimum tool wear and diametral error.展开更多
Drilling carbon fiber reinforced polymer(CFRP)composites is liable to generate serious defects including burrs,delamination,fiber pullouts and matrix cracking because of their inherent anisotropy in mechanical propert...Drilling carbon fiber reinforced polymer(CFRP)composites is liable to generate serious defects including burrs,delamination,fiber pullouts and matrix cracking because of their inherent anisotropy in mechanical properties.Therefore,studies on drilling quality during composites processing is necessary. The thrust force of different material drill bits in composites drilling process was measured by the dynamometer and the surface quality of the hole wall was observed by scanning electron microscope(SEM),moreover,the tool wear and its effects on the hole wall quality were also taken into account.展开更多
Rotation sintering, also known as slush molding, is used to manufacture molded skins, such as dashboards or door interior panels for cars. At present, approximately 80% of such molded skins are manufactured using elec...Rotation sintering, also known as slush molding, is used to manufacture molded skins, such as dashboards or door interior panels for cars. At present, approximately 80% of such molded skins are manufactured using electroforms to achieve the complex free-form surfaces, and surface structures, such as leather graining that the industry demands. The manufacture of these electroforms is, however, time-consuming and expensive. This project aims to replace conventional electroforms with laser-drilled molds. Holes in tool molds should be drilled by using laser radiation as part of an automated process. The system consists of a robot with a fiber-laser beam source. A CAx （computer-aided x） process chain has been developed for this purpose in which the CAD （computer-aided design） data of the tool molds are processed, drill hole fields generated, and a machine-specific RC （robot control） program created. Process-specific fundamentals, such as suitable process windows and process control, have been devised to manufacture holes using fiber laser radiation The advantages of the new laser-drilled tool molds may result in substituting them for conventional electroforms, allowing old markets to be re-entered or additional markets to be created and targeted through new molds or lower costs.展开更多
In the conformally covariant classical field theory, the energy-momemtum tensors for the massless spin 0, 1, 1/2 and 2 fields are traceless (Butut, A. O. & Xu, B. W., J.Phys., A15 L207; Xu, B. W., ibid., A14 L97; ...In the conformally covariant classical field theory, the energy-momemtum tensors for the massless spin 0, 1, 1/2 and 2 fields are traceless (Butut, A. O. & Xu, B. W., J.Phys., A15 L207; Xu, B. W., ibid., A14 L97; 15 L329; Birrell, N. D. & Davies, P.C. W., Quantum Fields in Curved Space, p. 174). On the other hand, it is well展开更多
文摘AIM： To introduce and evaluate the efficacy and technical aspects of endoscopic submucosal dissection （ESD） using a novel device, the Fork knife. METHODS： From March 2004 to April 2008, ESD was performed on 265 gastric lesions using a Fork knife （Endo FS） （group A） and on 72 gastric lesions using a Flexknife （group B） at a single tertiary referral center. We retrospectively compared the endoscopic characteristics of the tumors, pathological findings, and sizes of the resected specimens. We also compared the en b/oc resection rate, complete resection rate, complications, and procedure time between the two groups. RESULTS： The mean size of the resected specimens was 4.27 ± 1.26 cm in group A and 4.29 ± 1.48 cm in group B. The en b/oc resection rate was 95.8% （254/265 lesions） in group A and 93.1% （67/72） in group B. Complete ESD without tumor cell invasion of the resected margin was obtained in 81.1% （215/265） of group A and in 73.6% （53/72） of group B. The perforation rate was 0.8% （2/265） in group A and 1.4% （1/72） in group B. The mean procedure time was 59.63 ± 56.12 min in group A and 76.65 ± 70.75 min in group B （P 〈 0.05）. CONCLUSION： The Fork knife （Endo FS） is useful for clinical practice and has the advantage of reducing the procedure time.
文摘Cutting parameters were evaluated and optimized based on multiple performance characteristics including tool wear and size error of drilled hole. Taguchi＇s L27, 3-level, 4-factor orthogonal array was used for the tests. It is shown that generally abrasive wear and built up edge （BUE） formation were seen in the tool wear, and the comer wear was also of major importance. Flank wear of the cutting tool was found to be mostly dependent upon particle mass fraction, followed by feed rate, drill hardness and spindle speed, respectively. Among the tools used, TiAlN coated carbide drills showed the best performance with regard to the tool wear as well as hole size. Grey relational analysis indicated that drill material was the more influential parameter than feed rate and spindle speed. The results revealed that optimal combination of the drilling parameters could be used to obtain both minimum tool wear and diametral error.
文摘Drilling carbon fiber reinforced polymer(CFRP)composites is liable to generate serious defects including burrs,delamination,fiber pullouts and matrix cracking because of their inherent anisotropy in mechanical properties.Therefore,studies on drilling quality during composites processing is necessary. The thrust force of different material drill bits in composites drilling process was measured by the dynamometer and the surface quality of the hole wall was observed by scanning electron microscope(SEM),moreover,the tool wear and its effects on the hole wall quality were also taken into account.
文摘Rotation sintering, also known as slush molding, is used to manufacture molded skins, such as dashboards or door interior panels for cars. At present, approximately 80% of such molded skins are manufactured using electroforms to achieve the complex free-form surfaces, and surface structures, such as leather graining that the industry demands. The manufacture of these electroforms is, however, time-consuming and expensive. This project aims to replace conventional electroforms with laser-drilled molds. Holes in tool molds should be drilled by using laser radiation as part of an automated process. The system consists of a robot with a fiber-laser beam source. A CAx （computer-aided x） process chain has been developed for this purpose in which the CAD （computer-aided design） data of the tool molds are processed, drill hole fields generated, and a machine-specific RC （robot control） program created. Process-specific fundamentals, such as suitable process windows and process control, have been devised to manufacture holes using fiber laser radiation The advantages of the new laser-drilled tool molds may result in substituting them for conventional electroforms, allowing old markets to be re-entered or additional markets to be created and targeted through new molds or lower costs.
文摘In the conformally covariant classical field theory, the energy-momemtum tensors for the massless spin 0, 1, 1/2 and 2 fields are traceless (Butut, A. O. & Xu, B. W., J.Phys., A15 L207; Xu, B. W., ibid., A14 L97; 15 L329; Birrell, N. D. & Davies, P.C. W., Quantum Fields in Curved Space, p. 174). On the other hand, it is well
