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  • Open Access
    Authors: 
    Fangong Kong; Shoujuan Wang; Weijue Gao; Pedram Fatehi;
    Publisher: Royal Society of Chemistry (RSC)
    Project: NSERC

    Kraft lignin (KL) produced in kraft pulping process has a low molecular weight and solubility, which limits its application in industry. For the first time, KL was polymerized with acrylic acid (AA) in an acidic aqueous suspension system to produce a water soluble lignin–AA polymer with a high molecular weight in this work. The polymerization reaction was carried out using K2S2O8 as an initiator, and the influence of reaction conditions on the carboxylate group content and molecular weight of resultant lignin polymers was systematically investigated. The mechanism of polymerization of KL and AA was discussed fundamentally. The resulting lignin–AA polymer was characterized by Fourier Transform Infrared spectrophotometry (FTIR), proton nuclear magnetic resonance (1H-NMR) and elemental analyses. The results showed that the phenolic hydroxyl group (Ph-OH) content of KL promoted the polymerization under an acidic environment. Under the conditions of 1.5 wt% of initiator, 3.5 of pH, 10.0 of AA/lignin molar ratio, 0.15 mol L−1 of lignin concentration, 3 h and 80 °C, the carboxylate group content and the molecular weight of the polymer were 7.37 mmol g−1 and 7.4 × 105 g mol−1, respectively. The lignin–AA polymer was water soluble at a 10 g L−1 concentration and a pH higher than 4.5. Furthermore, the flocculation performance of lignin–AA polymer in an aluminium oxide suspension was evaluated. Compared with polyAA, the lignin–AA polymer was a more efficient flocculant for aluminium oxide suspension, which shows its potential to be used as a green flocculant in industry.

  • Closed Access
    Authors: 
    Tingting Yu; Yishuai Xu; Yifan Liu; Puren Ouyang; M.M. Gupta; W.J. Zhang; W.J. Zhang;
    Publisher: IEEE

    This paper reports a work on developing a novel charge control circuit for control of the piezoelectric actuator to overcome its hysteresis nonlinearity when the actuator is driven at high voltage (as opposed to low voltage reported in literature). The charge control circuit also includes a balancing resistor. A test-bed for a piezoelectric actuator was established and an experiment was conducted. The result showed that the hysteresis nonlinearity of the piezoelectric actuator was reduced by 82% under the proposed charge control circuit. This charge control circuit can be used for control of piezoelectric inertia-friction actuator, in which the piezoelectric actuator is part of the whole actuator system.

  • Open Access
    Authors: 
    J.J.M.C.H. de la Rosette; Hashim U. Ahmed; Jelle O. Barentsz; T.E. Bjerklund Johansen; Maurizio Brausi; Mark Emberton; Ferdinand Frauscher; D. Greene; Mukesh G. Harisinghani; Karin Haustermans; +12 more
    Publisher: Mary Ann Liebert Inc
    Country: Netherlands

    PURPOSE: To establish a consensus in relation to case selection, conduct of therapy, and outcomes that are associated with focal therapy for men with localized prostate cancer. MATERIAL AND METHODS: Urologic surgeons, radiation oncologists, radiologists, and histopathologists from North America and Europe participated in a consensus workshop on focal therapy for prostate cancer. The consensus process was face to face within a structured meeting, in which pertinent clinical issues were raised, discussed, and agreement sought. Where no agreement was possible, this was acknowledged, and the nature of the disagreement noted. RESULTS: Candidates for focal treatment should have unilateral low- to intermediate-risk disease with clinical stage

  • Authors: 
    Jinli Zhang; Ning Nie; Yuanyuan Liu; Jiao Wang; Feng Yu; Junjie Gu; Wei Li;
    Publisher: American Chemical Society (ACS)

    An evolutionary composite of LiFePO4 with nitrogen and boron codoped carbon layers was prepared by processing hydrothermal-synthesized LiFePO4. This novel codoping method is successfully applied to LiFePO4 for commercial use, and it achieved excellent electrochemical performance. The electrochemical performance can be improved through single nitrogen doping (LiFePO4/C-N) or boron doping (LiFePO4/C-B). When modifying the LiFePO4/C-B with nitrogen (to synthesis LiFePO4/C-B+N) the undesired nonconducting N-B configurations (190.1 and 397.9 eV) are generated. This decreases the electronic conductivity from 2.56×10(-2) to 1.30×10(-2) S cm(-1) resulting in weak electrochemical performance. Nevertheless, using the opposite order to decorate LiFePO4/C-N with boron (to obtain LiFePO4/C-N+B) not only eliminates the nonconducting N-B impurity, but also promotes the conductive C-N (398.3, 400.3, and 401.1 eV) and C-B (189.5 eV) configurations-this markedly improves the electronic conductivity to 1.36×10(-1) S cm(-1). Meanwhile the positive doping strategy leads to synergistic electrochemical activity distinctly compared with single N- or B-doped materials (even much better than their sum capacity at 20 C). Moreover, due to the electron and hole-type carriers donated by nitrogen and boron atoms, the N+B codoped carbon coating tremendously enhances the electrochemical property: at the rate of 20 C, the codoped sample can elevate the discharge capacity of LFP/C from 101.1 mAh g(-1) to 121.6 mAh g(-1), and the codoped product based on commercial LiFePO4/C shows a discharge capacity of 78.4 mAh g(-1) rather than 48.1 mAh g(-1). Nevertheless, the B+N codoped sample decreases the discharge capacity of LFP/C from 101.1 mAh g(-1) to 95.4 mAh g(-1), while the commercial LFP/C changes from 48.1 mAh g(-1) to 40.6 mAh g(-1).

  • Closed Access
    Authors: 
    Joan C. Tuinenburg; Gerhard Koning; Ellen Hekking; Colette Desjardins; François Harel; Luc Bilodeau; Anton W.M. van Weert; Jacques Lespérance; Johan H. C. Reiber;
    Publisher: Wiley

    To assess the magnitude of differences in QCA outcomes between two cooperating core laboratories in a single trial, we have carried out an inter-core laboratory variability study. Two QCA experts at the Montreal Heart Institute and Heart Core Leiden both analyzed 32 lesions (pre- and post-intervention) in accordance with previously agreed upon standard operating procedures. One of the experts analyzed the whole image set twice to determine the intraobserver variability. The inter-core laboratory differences in the acute gain (n = 31 pairs) are non-significant. The systematic errors of the individual measurements (n = 63 analyses) show an excellent intraclass correlation coefficient of reliability (>75%), except for the stent length (67.7%). The corresponding random errors are small. In general, the intra-observer systematic and random errors are both slightly smaller than those for the inter-core laboratory study. QCA analyses in clinical trials can be carried out in core laboratories at two different locations if and only if highly standardized conditions are maintained.

  • Closed Access
    Authors: 
    Duan Li; Christopher Wayne Schmidt;
    Publisher: Elsevier BV

    A smooth cost distribution can be a desirable feature in optimal control design when concerning even distribution of control energy and uniform resource allocation. This consideration is formulated in this paper for discrete-time linear systems where a square cost-variation term is attached to a primal quadratic performance index in an additive form. An analytical control law is obtained for the resulting non-linear-quadratic and nonseparable optimal control problem using a multilevel solution scheme. Investigating the trade-off between minimizing the primal quadratic performance index and minimizing the square cost-variation term offers some useful insights into multiobjective design of control systems.

  • Open Access
    Authors: 
    Societies Editorial Office;
    Publisher: MDPI AG

    The editors of Societies would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2013. [...]

  • Publication . Other literature type . Article . 2021
    Open Access
    Authors: 
    Shengnan Ke; Jun Gong; Songnian Li; Qing Zhu; Xintao Liu; Yeting Zhang;
    Publisher: Ryerson University Library and Archives

    In recent years, there has been tremendous growth in the field of indoor and outdoor positioning sensors continuously producing huge volumes of trajectory data that has been used in many fields such as location-based services or location intelligence. Trajectory data is massively increased and semantically complicated, which poses a great challenge on spatio-temporal data indexing. This paper proposes a spatio-temporal data indexing method, named HBSTR-tree, which is a hybrid index structure comprising spatio-temporal R-tree, B*-tree and Hash table. To improve the index generation efficiency, rather than directly inserting trajectory points, we group consecutive trajectory points as nodes according to their spatio-temporal semantics and then insert them into spatio-temporal R-tree as leaf nodes. Hash table is used to manage the latest leaf nodes to reduce the frequency of insertion. A new spatio-temporal interval criterion and a new node-choosing sub-algorithm are also proposed to optimize spatio-temporal R-tree structures. In addition, a B*-tree sub-index of leaf nodes is built to query the trajectories of targeted objects efficiently. Furthermore, a database storage scheme based on a NoSQL-type DBMS is also proposed for the purpose of cloud storage. Experimental results prove that HBSTR-tree outperforms TB*-tree in some aspects such as generation efficiency, query performance and query type.

  • Open Access
    Authors: 
    Andrew Spencer; Suzanne Lentzsch; Katja Weisel; Hervé Avet-Loiseau; Tomer M Mark; Ivan Spicka; Tamás Masszi; Birgitta Lauri; Mark-David Levin; Alberto Bosi; +27 more
    Publisher: Ferrata Storti Foundation (Haematologica)
    Countries: Netherlands, Italy

    Daratumumab, a CD38 human monoclonal antibody, demonstrated significant clinical activity in combination with bortezomib and dexamethasone versus bortezomib and dexamethasone alone in the primary analysis of CASTOR, a phase 3 study in relapsed and/or refractory multiple myeloma. A post hoc analysis based on treatment history and longer follow up is presented. After 19.4 (range: 0–27.7) months of median follow up, daratumumab plus bortezomib and dexamethasone prolonged progression-free survival (median: 16.7 versus 7.1 months; hazard ratio, 0.31; 95% confidence interval, 0.24-0.39; P12, ≤6, or >6 months), or cytogenetic risk. Minimal residual disease–negative rates were >2.5-fold higher with daratumumab across subgroups. The safety profile of daratumumab plus bortezomib and dexamethasone remained consistent with longer follow up. Daratumumab plus bortezomib and dexamethasone demonstrated significant clinical activity across clinically relevant subgroups and provided the greatest benefit to patients treated at first relapse. Trial registration: clinicaltrials.gov identifier: 02136134.

  • Open Access English
    Authors: 
    Nan Zhao; Fen Cheng; F. Richard Yu; Jie Tang; Yunfei Chen; Guan Gui; Hikmet Sari;
    Publisher: IEEE
    Country: United Kingdom

    Unmanned aerial vehicles (UAVs) can help smallcell base stations (SBSs) offload traffic via wireless backhaul to improve coverage and increase rate. However, the capacity of backhaul is limited. In this paper, UAV assisted secure transmission for scalable videos in hyper-dense networks via caching is studied. In the proposed scheme, UAVs can act as SBSs to provide videos to mobile users in some small cells. To reduce the pressure of wireless backhaul, UAVs and SBSs are both equipped with caches to store videos at off-peak time. To facilitate UAVs, a single antenna is equipped at each UAV and thus, only the precoding matrices of SBSs should be cooperatively designed to manage interference by exploiting the principle of interference alignment. On the other hand, the SBSs replaced by UAVs will be idle. Thus, in order to guarantee secure transmission, the idle SBSs can be further exploited to generate jamming signal to disrupt eavesdropping. The jamming signal is zero-forced at the legitimate users through the precoding of the idle SBSs, without affecting the legitimate transmission. The feasibility conditions of the proposed scheme are derived, and the secrecy performance is analyzed. Finally, simulation results are presented to verify the effectiveness of the proposed scheme.\ud

search
Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
126,291 Research products, page 1 of 12,630
  • Open Access
    Authors: 
    Fangong Kong; Shoujuan Wang; Weijue Gao; Pedram Fatehi;
    Publisher: Royal Society of Chemistry (RSC)
    Project: NSERC

    Kraft lignin (KL) produced in kraft pulping process has a low molecular weight and solubility, which limits its application in industry. For the first time, KL was polymerized with acrylic acid (AA) in an acidic aqueous suspension system to produce a water soluble lignin–AA polymer with a high molecular weight in this work. The polymerization reaction was carried out using K2S2O8 as an initiator, and the influence of reaction conditions on the carboxylate group content and molecular weight of resultant lignin polymers was systematically investigated. The mechanism of polymerization of KL and AA was discussed fundamentally. The resulting lignin–AA polymer was characterized by Fourier Transform Infrared spectrophotometry (FTIR), proton nuclear magnetic resonance (1H-NMR) and elemental analyses. The results showed that the phenolic hydroxyl group (Ph-OH) content of KL promoted the polymerization under an acidic environment. Under the conditions of 1.5 wt% of initiator, 3.5 of pH, 10.0 of AA/lignin molar ratio, 0.15 mol L−1 of lignin concentration, 3 h and 80 °C, the carboxylate group content and the molecular weight of the polymer were 7.37 mmol g−1 and 7.4 × 105 g mol−1, respectively. The lignin–AA polymer was water soluble at a 10 g L−1 concentration and a pH higher than 4.5. Furthermore, the flocculation performance of lignin–AA polymer in an aluminium oxide suspension was evaluated. Compared with polyAA, the lignin–AA polymer was a more efficient flocculant for aluminium oxide suspension, which shows its potential to be used as a green flocculant in industry.

  • Closed Access
    Authors: 
    Tingting Yu; Yishuai Xu; Yifan Liu; Puren Ouyang; M.M. Gupta; W.J. Zhang; W.J. Zhang;
    Publisher: IEEE

    This paper reports a work on developing a novel charge control circuit for control of the piezoelectric actuator to overcome its hysteresis nonlinearity when the actuator is driven at high voltage (as opposed to low voltage reported in literature). The charge control circuit also includes a balancing resistor. A test-bed for a piezoelectric actuator was established and an experiment was conducted. The result showed that the hysteresis nonlinearity of the piezoelectric actuator was reduced by 82% under the proposed charge control circuit. This charge control circuit can be used for control of piezoelectric inertia-friction actuator, in which the piezoelectric actuator is part of the whole actuator system.

  • Open Access
    Authors: 
    J.J.M.C.H. de la Rosette; Hashim U. Ahmed; Jelle O. Barentsz; T.E. Bjerklund Johansen; Maurizio Brausi; Mark Emberton; Ferdinand Frauscher; D. Greene; Mukesh G. Harisinghani; Karin Haustermans; +12 more
    Publisher: Mary Ann Liebert Inc
    Country: Netherlands

    PURPOSE: To establish a consensus in relation to case selection, conduct of therapy, and outcomes that are associated with focal therapy for men with localized prostate cancer. MATERIAL AND METHODS: Urologic surgeons, radiation oncologists, radiologists, and histopathologists from North America and Europe participated in a consensus workshop on focal therapy for prostate cancer. The consensus process was face to face within a structured meeting, in which pertinent clinical issues were raised, discussed, and agreement sought. Where no agreement was possible, this was acknowledged, and the nature of the disagreement noted. RESULTS: Candidates for focal treatment should have unilateral low- to intermediate-risk disease with clinical stage

  • Authors: 
    Jinli Zhang; Ning Nie; Yuanyuan Liu; Jiao Wang; Feng Yu; Junjie Gu; Wei Li;
    Publisher: American Chemical Society (ACS)

    An evolutionary composite of LiFePO4 with nitrogen and boron codoped carbon layers was prepared by processing hydrothermal-synthesized LiFePO4. This novel codoping method is successfully applied to LiFePO4 for commercial use, and it achieved excellent electrochemical performance. The electrochemical performance can be improved through single nitrogen doping (LiFePO4/C-N) or boron doping (LiFePO4/C-B). When modifying the LiFePO4/C-B with nitrogen (to synthesis LiFePO4/C-B+N) the undesired nonconducting N-B configurations (190.1 and 397.9 eV) are generated. This decreases the electronic conductivity from 2.56×10(-2) to 1.30×10(-2) S cm(-1) resulting in weak electrochemical performance. Nevertheless, using the opposite order to decorate LiFePO4/C-N with boron (to obtain LiFePO4/C-N+B) not only eliminates the nonconducting N-B impurity, but also promotes the conductive C-N (398.3, 400.3, and 401.1 eV) and C-B (189.5 eV) configurations-this markedly improves the electronic conductivity to 1.36×10(-1) S cm(-1). Meanwhile the positive doping strategy leads to synergistic electrochemical activity distinctly compared with single N- or B-doped materials (even much better than their sum capacity at 20 C). Moreover, due to the electron and hole-type carriers donated by nitrogen and boron atoms, the N+B codoped carbon coating tremendously enhances the electrochemical property: at the rate of 20 C, the codoped sample can elevate the discharge capacity of LFP/C from 101.1 mAh g(-1) to 121.6 mAh g(-1), and the codoped product based on commercial LiFePO4/C shows a discharge capacity of 78.4 mAh g(-1) rather than 48.1 mAh g(-1). Nevertheless, the B+N codoped sample decreases the discharge capacity of LFP/C from 101.1 mAh g(-1) to 95.4 mAh g(-1), while the commercial LFP/C changes from 48.1 mAh g(-1) to 40.6 mAh g(-1).

  • Closed Access
    Authors: 
    Joan C. Tuinenburg; Gerhard Koning; Ellen Hekking; Colette Desjardins; François Harel; Luc Bilodeau; Anton W.M. van Weert; Jacques Lespérance; Johan H. C. Reiber;
    Publisher: Wiley

    To assess the magnitude of differences in QCA outcomes between two cooperating core laboratories in a single trial, we have carried out an inter-core laboratory variability study. Two QCA experts at the Montreal Heart Institute and Heart Core Leiden both analyzed 32 lesions (pre- and post-intervention) in accordance with previously agreed upon standard operating procedures. One of the experts analyzed the whole image set twice to determine the intraobserver variability. The inter-core laboratory differences in the acute gain (n = 31 pairs) are non-significant. The systematic errors of the individual measurements (n = 63 analyses) show an excellent intraclass correlation coefficient of reliability (>75%), except for the stent length (67.7%). The corresponding random errors are small. In general, the intra-observer systematic and random errors are both slightly smaller than those for the inter-core laboratory study. QCA analyses in clinical trials can be carried out in core laboratories at two different locations if and only if highly standardized conditions are maintained.

  • Closed Access
    Authors: 
    Duan Li; Christopher Wayne Schmidt;
    Publisher: Elsevier BV

    A smooth cost distribution can be a desirable feature in optimal control design when concerning even distribution of control energy and uniform resource allocation. This consideration is formulated in this paper for discrete-time linear systems where a square cost-variation term is attached to a primal quadratic performance index in an additive form. An analytical control law is obtained for the resulting non-linear-quadratic and nonseparable optimal control problem using a multilevel solution scheme. Investigating the trade-off between minimizing the primal quadratic performance index and minimizing the square cost-variation term offers some useful insights into multiobjective design of control systems.

  • Open Access
    Authors: 
    Societies Editorial Office;
    Publisher: MDPI AG

    The editors of Societies would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2013. [...]

  • Publication . Other literature type . Article . 2021
    Open Access
    Authors: 
    Shengnan Ke; Jun Gong; Songnian Li; Qing Zhu; Xintao Liu; Yeting Zhang;
    Publisher: Ryerson University Library and Archives

    In recent years, there has been tremendous growth in the field of indoor and outdoor positioning sensors continuously producing huge volumes of trajectory data that has been used in many fields such as location-based services or location intelligence. Trajectory data is massively increased and semantically complicated, which poses a great challenge on spatio-temporal data indexing. This paper proposes a spatio-temporal data indexing method, named HBSTR-tree, which is a hybrid index structure comprising spatio-temporal R-tree, B*-tree and Hash table. To improve the index generation efficiency, rather than directly inserting trajectory points, we group consecutive trajectory points as nodes according to their spatio-temporal semantics and then insert them into spatio-temporal R-tree as leaf nodes. Hash table is used to manage the latest leaf nodes to reduce the frequency of insertion. A new spatio-temporal interval criterion and a new node-choosing sub-algorithm are also proposed to optimize spatio-temporal R-tree structures. In addition, a B*-tree sub-index of leaf nodes is built to query the trajectories of targeted objects efficiently. Furthermore, a database storage scheme based on a NoSQL-type DBMS is also proposed for the purpose of cloud storage. Experimental results prove that HBSTR-tree outperforms TB*-tree in some aspects such as generation efficiency, query performance and query type.

  • Open Access
    Authors: 
    Andrew Spencer; Suzanne Lentzsch; Katja Weisel; Hervé Avet-Loiseau; Tomer M Mark; Ivan Spicka; Tamás Masszi; Birgitta Lauri; Mark-David Levin; Alberto Bosi; +27 more
    Publisher: Ferrata Storti Foundation (Haematologica)
    Countries: Netherlands, Italy

    Daratumumab, a CD38 human monoclonal antibody, demonstrated significant clinical activity in combination with bortezomib and dexamethasone versus bortezomib and dexamethasone alone in the primary analysis of CASTOR, a phase 3 study in relapsed and/or refractory multiple myeloma. A post hoc analysis based on treatment history and longer follow up is presented. After 19.4 (range: 0–27.7) months of median follow up, daratumumab plus bortezomib and dexamethasone prolonged progression-free survival (median: 16.7 versus 7.1 months; hazard ratio, 0.31; 95% confidence interval, 0.24-0.39; P12, ≤6, or >6 months), or cytogenetic risk. Minimal residual disease–negative rates were >2.5-fold higher with daratumumab across subgroups. The safety profile of daratumumab plus bortezomib and dexamethasone remained consistent with longer follow up. Daratumumab plus bortezomib and dexamethasone demonstrated significant clinical activity across clinically relevant subgroups and provided the greatest benefit to patients treated at first relapse. Trial registration: clinicaltrials.gov identifier: 02136134.

  • Open Access English
    Authors: 
    Nan Zhao; Fen Cheng; F. Richard Yu; Jie Tang; Yunfei Chen; Guan Gui; Hikmet Sari;
    Publisher: IEEE
    Country: United Kingdom

    Unmanned aerial vehicles (UAVs) can help smallcell base stations (SBSs) offload traffic via wireless backhaul to improve coverage and increase rate. However, the capacity of backhaul is limited. In this paper, UAV assisted secure transmission for scalable videos in hyper-dense networks via caching is studied. In the proposed scheme, UAVs can act as SBSs to provide videos to mobile users in some small cells. To reduce the pressure of wireless backhaul, UAVs and SBSs are both equipped with caches to store videos at off-peak time. To facilitate UAVs, a single antenna is equipped at each UAV and thus, only the precoding matrices of SBSs should be cooperatively designed to manage interference by exploiting the principle of interference alignment. On the other hand, the SBSs replaced by UAVs will be idle. Thus, in order to guarantee secure transmission, the idle SBSs can be further exploited to generate jamming signal to disrupt eavesdropping. The jamming signal is zero-forced at the legitimate users through the precoding of the idle SBSs, without affecting the legitimate transmission. The feasibility conditions of the proposed scheme are derived, and the secrecy performance is analyzed. Finally, simulation results are presented to verify the effectiveness of the proposed scheme.\ud