The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Sylwia Golba - One of the best experts on this subject based on the ideXlab platform.
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Ring-opening polymerization of monosubstituted oxiranes in the presence of potassium hydride: determination of initiation course and structure of macromolecules by MALDI-TOF mass spectrometry
Journal of Polymer Research, 2019Co-Authors: Zbigniew Grobelny, Justyna Jurek-suliga, Sylwia GolbaAbstract:Several monosubstituted oxiranes were polymerized with suspension of potassium hydride (KH) in tetrahydrofuran (THF) at room temperature. This heterogeneous process resulted in polyethers with various starting groups depending on the kind of monomer. The macromolecules formed in ring-opening polymerization of monosubstituted oxiranes were analyzed by Matrix Assisted Laser Desorption/Ionization - Time of Flight Mass Spectrometry (MALDI-TOF MS). It was stated, that initiation of propylene oxide (PO) polymerization with KH proceeded via three ways, i.e. cleavage of oxirane ring in the β-position, monomer deprotonation and deoxygenation. Potassium isopropoxide, potassium allyloxide and potassium hydroxide were the real initiators. The main reactions, which occur in the initiation step, depend on the type of monomer used. In the case of allyl glycidyl ether (AGE) and phenyl glycidyl ether (PGE) deprotonation of the monomer did not occur. During initiation of glycidyl ethers oxirane ring was opened and also linear ether bond between glycidyl group and oxygen atom was cleaved under influence of KH. Interestingly, formation of new kinds of macromolecules was observed in the systems containing glycidyl ethers, which do not possess mers of the monomers used. Mechanisms of the studied processes were presented and discussed. Carbon-13 Nuclear Magnetic Resonance (^13C NMR) was used as Supporting Technique for analysis of the obtained polymers. Number average molar masses of the polymers (M_n) determined by Size Exclusion Chromatography (SEC) were about two times higher than calculated ones. It indicated that half of used KH did not take part in the initiation step. Graphical abstract Scheme of ROP of monosubstituted oxiranes in the presence of potassium hydride
Shizhi Xue - One of the best experts on this subject based on the ideXlab platform.
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High-resistance controlled yielding Supporting Technique in deep-well oil shale roadways
International Journal of Mining Science and Technology, 2014Co-Authors: Jianbiao Bai, Xiangyu Wang, Junde Wang, Shizhi XueAbstract:Abstract In order to avoid the deep-well oil shale roadway being deformed, damaged, or difficult to maintain after excavating and Supporting in Haishiwan coal mine, this paper has analyzed the characteristics of the deformed roadway and revealed its failure mechanism by taking comprehensively the methods of field geological investigation, displacement monitoring of surrounding rock, rock properties and hydration properties experiments and field application tests. Based on this work, the high-resistance controlled yielding Supporting principle is proposed, which is: to “resist” by high pre-tightening force and high stiffness in the early stage, to “yield” by making use of the controlled deformation of a yielding tube in the middle stage, and to “fix” by applying total-section Gunite in the later stage. A high-resistance controlled yielding Supporting Technique of “high pre-tightening force yielding anchor bolt + small-bore pre-tightening force anchor cable + rebar ladder beam + rhombic metal mesh + lagging gunite” has been established, and industrial on site testing implemented. The practical results show that the high-resistance controlled yielding Supporting Technique can effectively control the large deformation and long-time rheology of deep-well oil shale roadways and can provide beneficial references for the maintenance of other con-generic roadways.
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High-resistance controlled yielding Supporting Technique in deep-well oil shale roadways
Elsevier, 2014Co-Authors: Jianbiao Bai, Xiangyu Wang, Junde Wang, Shizhi XueAbstract:In order to avoid the deep-well oil shale roadway being deformed, damaged, or difficult to maintain after excavating and Supporting in Haishiwan coal mine, this paper has analyzed the characteristics of the deformed roadway and revealed its failure mechanism by taking comprehensively the methods of field geological investigation, displacement monitoring of surrounding rock, rock properties and hydration properties experiments and field application tests. Based on this work, the high-resistance controlled yielding Supporting principle is proposed, which is: to “resist” by high pre-tightening force and high stiffness in the early stage, to “yield” by making use of the controlled deformation of a yielding tube in the middle stage, and to “fix” by applying total-section Gunite in the later stage. A high-resistance controlled yielding Supporting Technique of “high pre-tightening force yielding anchor bolt + small-bore pre-tightening force anchor cable + rebar ladder beam + rhombic metal mesh + lagging gunite” has been established, and industrial on site testing implemented. The practical results show that the high-resistance controlled yielding Supporting Technique can effectively control the large deformation and long-time rheology of deep-well oil shale roadways and can provide beneficial references for the maintenance of other con-generic roadways. Keywords: Deep-well, Oil shale, Deformation failure mechanism, High-resistance controlled yielding Supporting, Yielding anchor bol
Dong Han-xion - One of the best experts on this subject based on the ideXlab platform.
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On application of soil nail wall support Technique in support engineering of cutting slope
2009Co-Authors: Dong Han-xionAbstract:Based on the detailed study on the geological condition of the outward special road construction of Xiluodu hydropower station,the paper points out measures for the adoption of soil nail wall in slope treatment,introduces the general principle and design method of the soil nail wall design,so as to expend the application of the soil nail wall Supporting Technique in engineering.
Zbigniew Grobelny - One of the best experts on this subject based on the ideXlab platform.
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Ring-opening polymerization of monosubstituted oxiranes in the presence of potassium hydride: determination of initiation course and structure of macromolecules by MALDI-TOF mass spectrometry
Journal of Polymer Research, 2019Co-Authors: Zbigniew Grobelny, Justyna Jurek-suliga, Sylwia GolbaAbstract:Several monosubstituted oxiranes were polymerized with suspension of potassium hydride (KH) in tetrahydrofuran (THF) at room temperature. This heterogeneous process resulted in polyethers with various starting groups depending on the kind of monomer. The macromolecules formed in ring-opening polymerization of monosubstituted oxiranes were analyzed by Matrix Assisted Laser Desorption/Ionization - Time of Flight Mass Spectrometry (MALDI-TOF MS). It was stated, that initiation of propylene oxide (PO) polymerization with KH proceeded via three ways, i.e. cleavage of oxirane ring in the β-position, monomer deprotonation and deoxygenation. Potassium isopropoxide, potassium allyloxide and potassium hydroxide were the real initiators. The main reactions, which occur in the initiation step, depend on the type of monomer used. In the case of allyl glycidyl ether (AGE) and phenyl glycidyl ether (PGE) deprotonation of the monomer did not occur. During initiation of glycidyl ethers oxirane ring was opened and also linear ether bond between glycidyl group and oxygen atom was cleaved under influence of KH. Interestingly, formation of new kinds of macromolecules was observed in the systems containing glycidyl ethers, which do not possess mers of the monomers used. Mechanisms of the studied processes were presented and discussed. Carbon-13 Nuclear Magnetic Resonance (^13C NMR) was used as Supporting Technique for analysis of the obtained polymers. Number average molar masses of the polymers (M_n) determined by Size Exclusion Chromatography (SEC) were about two times higher than calculated ones. It indicated that half of used KH did not take part in the initiation step. Graphical abstract Scheme of ROP of monosubstituted oxiranes in the presence of potassium hydride
Elisa Donati - One of the best experts on this subject based on the ideXlab platform.
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Live Demonstration : Sensor fusion using EMG and vision for hand gesture classification in mobile applications
2019Co-Authors: Enea Ceolini, Gemma Taverni, Lyes Khacef, Melika Payvand, Elisa DonatiAbstract:The discrimination of human gestures using wearable solutions is extremely important as a Supporting Technique for assisted living, healthcare of the elderly and neurorehabilitation. This paper presents a mobile electromyography (EMG) analysis framework to be an auxiliary component in physiotherapy sessions or as a feedback for neuroprosthesis calibration. We implemented a framework that allows the integration of multisensors, EMG and visual information, to perform sensor fusion and to improve the accuracy of hand gesture recognition tasks. In particular, we used an event-based camera adapted to run on the limited computational resources of mobile phones. We introduced a new publicly available dataset of sensor fusion for hand gesture recognition recorded from 10 subjects and used it to train the recognition models offline. We compare the online results of the hand gesture recognition using the fusion approach with the individual sensors with an improvement in the accuracy of 13% and 11%, for EMG and vision respectively, reaching 85%.
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Sensor fusion using EMG and vision for hand gesture classification in mobile applications
2019Co-Authors: Enea Ceolini, Gemma Taverni, Lyes Khacef, Melika Payvand, Elisa DonatiAbstract:The discrimination of human gestures using wearable solutions is extremely important as a Supporting Technique for assisted living, healthcare of the elderly and neurorehabilitation. This paper presents a mobile electromyography (EMG) analysis framework to be an auxiliary component in physiotherapy sessions or as a feedback for neuroprosthesis calibration. We implemented a framework that allows the integration of multisensors, EMG and visual information, to perform sensor fusion and to improve the accuracy of hand gesture recognition tasks. In particular, we used an event-based camera adapted to run on the limited computational resources of mobile phones. We introduced a new publicly available dataset of sensor fusion for hand gesture recognition recorded from 10 subjects and used it to train the recognition models offline. We compare the online results of the hand gesture recognition using the fusion approach with the individual sensors with an improvement in the accuracy of 13% and 11%, for EMG and vision respectively, reaching 85%.
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Sensor fusion using EMG and vision for hand gesture classification in mobile applications
2019Co-Authors: Enea Ceolini, Gemma Taverni, Lyes Khacef, Melika Payvand, Elisa DonatiAbstract:The discrimination of human gestures using wearable solutions is extremely important as a Supporting Technique for assisted living, healthcare of the elderly and neurorehabilitation. This paper presents a mobile electromyography (EMG) analysis framework to be an auxiliary component in physiotherapy sessions or as a feedback for neuroprosthesis calibration. We implemented a framework that allows the integration of multisensors, EMG and visual information, to perform sensor fusion and to improve the accuracy of hand gesture recognition tasks. In particular, we used an event-based camera adapted to run on the limited computational resources of mobile phones. We introduced a new publicly available dataset of sensor fusion for hand gesture recognition recorded from 10 subjects and used it to train the recognition models offline. We compare the online results of the hand gesture recognition using the fusion approach with the individual sensors with an improvement in the accuracy of 13% and 11%, for EMG and vision respectively, reaching 85%.