The construction of shield tunneling method, there are often phenomena such as tool wear, breakage and collapse of shield tunneling machine, which lead to downtime and affect the construction period. In this paper, ba...The construction of shield tunneling method, there are often phenomena such as tool wear, breakage and collapse of shield tunneling machine, which lead to downtime and affect the construction period. In this paper, based on the actual situation of two large diameter mud and water shield tunneling machine entering the warehouse and changing the tool, the amount of tool wear is counted, calculated, analyzed and optimized design. Conclusion: 1. the rationality of tool alloy height;2. the importance of cutting tool layering and reasonable arrangement;3. increase the number of tools on the same track as much as possible;4. the wear limit of the tool is reasonably determined by calculation to provide theoretical support for the frequency and reasonable tool change time of warehousing;5. reasonable arrangement of cutter head tool to avoid the phenomenon of tool waste.展开更多
For the first time in the world advanced multi layered Red Mud and MWCNTs (ARMC) based EMI shielding material has been developed at CSIR-AMPRI, Bhopal. Red mud provides oxides of titanium and iron as precursor and the...For the first time in the world advanced multi layered Red Mud and MWCNTs (ARMC) based EMI shielding material has been developed at CSIR-AMPRI, Bhopal. Red mud provides oxides of titanium and iron as precursor and the MWCNTs provides electrical conductivity characteristics necessary for making desired EMI shielding materials. The novel process involves unique designing of chemical compositions and mineralogical phases of red mud, MWCNTs together with appropriate additive and solvent which results in the simultaneous and synergistic chemical reactions among various constituents thereby forming tailored precursor powder. Further, the ceramic processing of tailored precursor powder in appropriate environment enables formation of advanced ARMC shielding material having a variety of ceramic phases with multi elemental compositions and multi layered crystal structures. The synthesized material was characterized by various techniques namely XRD, PL, FESEM, EDXA. The reflection loss (R. L.) of the sample was calculated based on the measured complex permittivity and permeability. The advanced ARMC material with thickness t = 1.5 mm showed a minimum R. L. of -35.5 Db at 14.0 GHz with a response band width of 1.8 GHz. Thus, the developed advanced ARMC material acts as a good EMI wave absorber.展开更多
文摘The construction of shield tunneling method, there are often phenomena such as tool wear, breakage and collapse of shield tunneling machine, which lead to downtime and affect the construction period. In this paper, based on the actual situation of two large diameter mud and water shield tunneling machine entering the warehouse and changing the tool, the amount of tool wear is counted, calculated, analyzed and optimized design. Conclusion: 1. the rationality of tool alloy height;2. the importance of cutting tool layering and reasonable arrangement;3. increase the number of tools on the same track as much as possible;4. the wear limit of the tool is reasonably determined by calculation to provide theoretical support for the frequency and reasonable tool change time of warehousing;5. reasonable arrangement of cutter head tool to avoid the phenomenon of tool waste.
文摘For the first time in the world advanced multi layered Red Mud and MWCNTs (ARMC) based EMI shielding material has been developed at CSIR-AMPRI, Bhopal. Red mud provides oxides of titanium and iron as precursor and the MWCNTs provides electrical conductivity characteristics necessary for making desired EMI shielding materials. The novel process involves unique designing of chemical compositions and mineralogical phases of red mud, MWCNTs together with appropriate additive and solvent which results in the simultaneous and synergistic chemical reactions among various constituents thereby forming tailored precursor powder. Further, the ceramic processing of tailored precursor powder in appropriate environment enables formation of advanced ARMC shielding material having a variety of ceramic phases with multi elemental compositions and multi layered crystal structures. The synthesized material was characterized by various techniques namely XRD, PL, FESEM, EDXA. The reflection loss (R. L.) of the sample was calculated based on the measured complex permittivity and permeability. The advanced ARMC material with thickness t = 1.5 mm showed a minimum R. L. of -35.5 Db at 14.0 GHz with a response band width of 1.8 GHz. Thus, the developed advanced ARMC material acts as a good EMI wave absorber.
