The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Emil H Schemitsch - One of the best experts on this subject based on the ideXlab platform.
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the effect of screw pullout rate on screw purchase in synthetic cancellous bone
Journal of Biomechanical Engineering-transactions of The Asme, 2009Co-Authors: Rad Zdero, Emil H SchemitschAbstract:Clinically, orthopaedic fracture fixation constructs are mounted using screws inserted into cancellous bone, while biomechanical studies are increasingly using commercially available synthetic bones. The goal of this study was to examine the effect of screw pullout rate on cancellous bone screw purchase strength in synthetic cancellous bone. Sixty synthetic cancellous bone cubes (40X40X40 mm 3 ) each had one orthopaedic cancellous bone screw (major diameter=6.5 mm) inserted to a depth of 30 mm. Screws were extracted to obtain outcome measures of failure force, failure shear stress, failure Energy, failure displacement, resistance force, and Removal Energy. The ten test groups (n =6 cubes per group) had screws extracted at pullout rates of 1 mm/min, 2.5 mmlmin, 5 mm/min, 7.5 mmlmin, 10 mmlmin, 20 mmlmin, 30 mm/min, 40 mmlmin, 50 mm/min, and 60 mm/min. The aggregate average results for failure force, failure stress, failure Energy, failure displacement, resistance force, and postfailure Removal Energy for combined pullout rates were, respectively, 984.8 ± 63.9N, 3.5±0.2 MPa, 298.3±41.7J, 0.53±0.08 mm, 453.8 ± 19.6 N, and 5420.1 ±489.7 J. Most statistical differences (40 of 47) involved either the 5 mmlmin or the 60 mm/min rates being compared to other rates. Failure force, failure stress, and resistance force increased and were highly linearly correlated with pullout rate (R 2 =0.78, 0.76, and 0.74, respectively). Failure Energy, failure displacement, and Removal Energy were relatively unchanged over the pullout range tested, yielding low correlation coefficients (R 2 <0.05). Failure force, failure stress, and resistance force were affected by bone screw pullout rate in synthetic cancellous bone, while failure Energy, failure displacement, and Removal Energy remained unchanged. This is the first study to perform an extensive investigation of cancellous bone screw pullout rate in synthetic cancellous bone.
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The effect of screw pullout rate on screw purchase in synthetic cancellous bone.
Journal of biomechanical engineering, 2008Co-Authors: Rad Zdero, Emil H SchemitschAbstract:Clinically, orthopaedic fracture fixation constructs are mounted using screws inserted into cancellous bone, while biomechanical studies are increasingly using commercially available synthetic bones. The goal of this study was to examine the effect of screw pullout rate on cancellous bone screw purchase strength in synthetic cancellous bone. Sixty synthetic cancellous bone cubes (40X40X40 mm 3 ) each had one orthopaedic cancellous bone screw (major diameter=6.5 mm) inserted to a depth of 30 mm. Screws were extracted to obtain outcome measures of failure force, failure shear stress, failure Energy, failure displacement, resistance force, and Removal Energy. The ten test groups (n =6 cubes per group) had screws extracted at pullout rates of 1 mm/min, 2.5 mmlmin, 5 mm/min, 7.5 mmlmin, 10 mmlmin, 20 mmlmin, 30 mm/min, 40 mmlmin, 50 mm/min, and 60 mm/min. The aggregate average results for failure force, failure stress, failure Energy, failure displacement, resistance force, and postfailure Removal Energy for combined pullout rates were, respectively, 984.8 ± 63.9N, 3.5±0.2 MPa, 298.3±41.7J, 0.53±0.08 mm, 453.8 ± 19.6 N, and 5420.1 ±489.7 J. Most statistical differences (40 of 47) involved either the 5 mmlmin or the 60 mm/min rates being compared to other rates. Failure force, failure stress, and resistance force increased and were highly linearly correlated with pullout rate (R 2 =0.78, 0.76, and 0.74, respectively). Failure Energy, failure displacement, and Removal Energy were relatively unchanged over the pullout range tested, yielding low correlation coefficients (R 2
Rad Zdero - One of the best experts on this subject based on the ideXlab platform.
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the effect of screw pullout rate on screw purchase in synthetic cancellous bone
Journal of Biomechanical Engineering-transactions of The Asme, 2009Co-Authors: Rad Zdero, Emil H SchemitschAbstract:Clinically, orthopaedic fracture fixation constructs are mounted using screws inserted into cancellous bone, while biomechanical studies are increasingly using commercially available synthetic bones. The goal of this study was to examine the effect of screw pullout rate on cancellous bone screw purchase strength in synthetic cancellous bone. Sixty synthetic cancellous bone cubes (40X40X40 mm 3 ) each had one orthopaedic cancellous bone screw (major diameter=6.5 mm) inserted to a depth of 30 mm. Screws were extracted to obtain outcome measures of failure force, failure shear stress, failure Energy, failure displacement, resistance force, and Removal Energy. The ten test groups (n =6 cubes per group) had screws extracted at pullout rates of 1 mm/min, 2.5 mmlmin, 5 mm/min, 7.5 mmlmin, 10 mmlmin, 20 mmlmin, 30 mm/min, 40 mmlmin, 50 mm/min, and 60 mm/min. The aggregate average results for failure force, failure stress, failure Energy, failure displacement, resistance force, and postfailure Removal Energy for combined pullout rates were, respectively, 984.8 ± 63.9N, 3.5±0.2 MPa, 298.3±41.7J, 0.53±0.08 mm, 453.8 ± 19.6 N, and 5420.1 ±489.7 J. Most statistical differences (40 of 47) involved either the 5 mmlmin or the 60 mm/min rates being compared to other rates. Failure force, failure stress, and resistance force increased and were highly linearly correlated with pullout rate (R 2 =0.78, 0.76, and 0.74, respectively). Failure Energy, failure displacement, and Removal Energy were relatively unchanged over the pullout range tested, yielding low correlation coefficients (R 2 <0.05). Failure force, failure stress, and resistance force were affected by bone screw pullout rate in synthetic cancellous bone, while failure Energy, failure displacement, and Removal Energy remained unchanged. This is the first study to perform an extensive investigation of cancellous bone screw pullout rate in synthetic cancellous bone.
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The effect of screw pullout rate on screw purchase in synthetic cancellous bone.
Journal of biomechanical engineering, 2008Co-Authors: Rad Zdero, Emil H SchemitschAbstract:Clinically, orthopaedic fracture fixation constructs are mounted using screws inserted into cancellous bone, while biomechanical studies are increasingly using commercially available synthetic bones. The goal of this study was to examine the effect of screw pullout rate on cancellous bone screw purchase strength in synthetic cancellous bone. Sixty synthetic cancellous bone cubes (40X40X40 mm 3 ) each had one orthopaedic cancellous bone screw (major diameter=6.5 mm) inserted to a depth of 30 mm. Screws were extracted to obtain outcome measures of failure force, failure shear stress, failure Energy, failure displacement, resistance force, and Removal Energy. The ten test groups (n =6 cubes per group) had screws extracted at pullout rates of 1 mm/min, 2.5 mmlmin, 5 mm/min, 7.5 mmlmin, 10 mmlmin, 20 mmlmin, 30 mm/min, 40 mmlmin, 50 mm/min, and 60 mm/min. The aggregate average results for failure force, failure stress, failure Energy, failure displacement, resistance force, and postfailure Removal Energy for combined pullout rates were, respectively, 984.8 ± 63.9N, 3.5±0.2 MPa, 298.3±41.7J, 0.53±0.08 mm, 453.8 ± 19.6 N, and 5420.1 ±489.7 J. Most statistical differences (40 of 47) involved either the 5 mmlmin or the 60 mm/min rates being compared to other rates. Failure force, failure stress, and resistance force increased and were highly linearly correlated with pullout rate (R 2 =0.78, 0.76, and 0.74, respectively). Failure Energy, failure displacement, and Removal Energy were relatively unchanged over the pullout range tested, yielding low correlation coefficients (R 2
E.y. Paryev - One of the best experts on this subject based on the ideXlab platform.
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Antikaon production and medium effects in proton-nucleus reactions at subthreshold beam energies
Physics of Atomic Nuclei, 2001Co-Authors: E.y. ParyevAbstract:Inclusive K ^−-meson production in proton-nucleus collisions in the subthreshold-Energy regime is analyzed within an appropriate folding model for incoherent primary proton-nucleon and secondary pion-nucleon production processes, which takes properly into account the struck-target-nucleon momentum and Removal-Energy distribution (nucleon spectral function), novel elementary cross sections for proton-nucleon reaction channels close to threshold, as well as nuclear mean-field potential effects on the one-step and two-step antikaon-creation processes. A detailed comparison of the model calculations of the K ^− differential cross sections for the reactions p +^9Be and p +^63Cu at subthreshold energies with the first experimental data obtained at the ITEP proton synchrotron is given. It displays both the relative role of the primary and secondary production channels at incident energies considered and the contributions to K ^− production that come from the use of the single-particle part and high-momentum-Energy part of the nucleon spectral function. It is found that the pion-nucleon production channel does not dominate in the subthreshold “hard” antikaon production in p ^9Be and p ^63Cu collisions and that the main contributions to the antikaon yields here come from the direct K ^−-production mechanism. The influence of the nucleon, kaon, and antikaon mean-field potentials on the K ^− yield is explored. It is shown that the effect of the nucleon mean field is of importance in explaining the considered experimental data on “hard” antikaon production, whereas the K ^+ and K ^− optical potentials play a minor role. The sensitivity of subthreshold “soft” antikaon production in p ^9Be reactions to the nucleon, kaon, and antikaon mean fields is studied. It is demonstrated that, contrary to the case of “hard” antikaon production, the K ^− potential has a very strong effect on the K ^− yield, which is comparable with that from the nucleon effective potential.
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Subthreshold and near-threshold K ^+-meson photoproduction on nuclei
Physics of Atomic Nuclei, 2000Co-Authors: E.y. ParyevAbstract:The inclusive K ^+-meson production in photon-induced reactions in the near-threshold and subthreshold Energy regimes is analyzed for the one-step (γ N → K ^+ Y , Y =Λ, Σ) incoherent production processes on the basis of an appropriate new folding model that takes properly into account the struck-target nucleonRemoval Energy and the internal momentum distribution (nucleon spectral function), extracted from recent quasielastic-electron-scattering experiments and from many-body calculations based on realistic models of NN interaction. Simple parametrizations of the total and differential cross sections for K ^+ production in photon-nucleon collisions are presented. A comparison of the model calculations of the K ^+ differential cross sections for γ^12C interactions in the threshold region with existing experimental data is given, which displays the contributions to K ^+ production at considered incident energies from the use of the single-particle part, as well as high momentum and high Removal Energy part, of the nucleon spectral function. Detailed predictions for the K ^+ total and differential cross sections for γ^2H, γ^12C, and γ^208Pb interactions at subthreshold and near-threshold energies are provided. The effect of the uncertainties in the elementary K ^+-production cross sections on the K ^+ yield is explored.
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Subthreshold and near threshold K + meson photoproduction\newline on nuclei
The European Physical Journal A, 2000Co-Authors: E.y. ParyevAbstract:The inclusive K+ meson production in photon–induced reactions in the near threshold and subthreshold Energy regimes is analyzed with respect to the one–step (γN→K + Y, Y=Λ,Σ) incoherent production processes on the basis of an appropriate new folding model, which takes properly into account the struck target nucleon Removal Energy and internal momentum distribution (nucleon spectral function), extracted from recent quasielastic electron scattering experiments and from many–body calculations with realistic models of the NN interaction. Simple parametrizations for the total and differential cross sections of the K+ production in photon–nucleon collisions are presented. Comparison of the model calculations of the K+ differential cross sections for the reaction γ+C12 in the threshold region with the existing experimental data is given, that displays the contributions to the K+ production at considered incident energies coming from the use of the single–particle part as well as high momentum and high Removal Energy part of the nucleon spectral function. Detailed predictions for the K+ total and differential cross sections from γH2, γC12 and γPb208 reactions at subthreshold and near threshold energies are provided. The influence of the uncertainties in the elementary K+ production cross sections on the K+ yield is explored.
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Subthreshold and near-threshold K+-meson production on light nuclei by protons
The European Physical Journal A, 1999Co-Authors: E.y. ParyevAbstract:Inclusive K+-meson production in proton-nucleus collisions in the near-threshold and subthreshold Energy regimes is analyzed with respect to the one-step (pN → K+YN, Y=Λ, Σ) and two-step (pN → NNπ, NN2π; πN → K+Y) incoherent production processes. An appropriate folding model is used that properly takes into account the struck-target-nucleon-Removal Energy and the momentum distribution (nucleon spectral function), novel elementary cross sections for proton-nucleon reaction channel close to threshold, as well as nuclear-mean-field-potential effects on the one-step and two-step kaon-creation processes. A detailed comparison of the model calculations of the K+ total and differential cross sections for the p+9Be and p+12C interactions with the existing experimental data is given, which displays both the relative role of the primary and secondary production channels at considered incident energies and those features of the cross sections that are sensitive to the high-momentum and high-Removal-Energy parts of the nucleon spectral function. It is found that, contrary to previous studies known in the literature, the pion-nucleon production channels do not necessarily dominate in pA collisions at subthreshold energies and that the relative strength of the proton-and pion-induced reaction channels for light target nuclei in the subthreshold Energy regime is governed by the kinematics of the experiment under consideration.
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Subthreshold $K^+$ meson production in proton–nucleus reactions and nucleon spectral function
The European Physical Journal A, 1998Co-Authors: S. V. Efremov, E.y. ParyevAbstract:The inclusive K+ meson production in proton–nucleus collisions in the near threshold and subthreshold Energy regimes is analyzed with respect to the one–step (pN→K+YN, Y=Λ,Σ) and two–step (pN→NNπ, NN2π; πN→K+Y) incoherent production processes on the basis of an appropriate new folding model, which takes properly into account the struck target nucleon Removal Energy and momentum distribution (nucleon spectral function), extracted from recent quasielastic electron scattering experiments and from many–body calculations with realistic models of the NN interaction. Comparison of the model calculations of the K+ total and double differential cross sections for the reaction p+C12 with the existing experimental data is given, illustrating both the relative role of the primary and secondary production channels at considered incident energies and those features of the cross sections which are sensitive to the high momentum and high Removal Energy part of the nucleon spectral function that is governed by nucleon–nucleon short–range and tensor correlations. It is found that the in–medium modifications of the available for pion and kaon production invariant energies squared due to the respective optical potentials are needed to account for considered experimental data.
Lawrence A Kennedy - One of the best experts on this subject based on the ideXlab platform.
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experimental assessment of pulsed corona discharge for treatment of voc emissions
Plasma Chemistry and Plasma Processing, 2003Co-Authors: Mario G Sobacchi, Alexei V Saveliev, Alexander Fridman, A F Gutsol, Lawrence A KennedyAbstract:The application of the pulsed corona discharge was experimentally evaluated for the treatment of VOC mixtures typically present in the exhaust streams of wood processing industry. Methanol, acetone, dimethyl sulfide, and α-pinene were selected as representative VOC compounds. An experimental database for the destruction and Removal efficiencies and Energy costs was produced for individual VOCs and their mixtures valid for input concentrations (5 to 1000 ppm), temperatures (25 to 200°C) and relative humidity (0 to 100%). High Removal efficiencies and destruction rates above 99% were obtained with power levels competitive with the present technologies for VOC Removal. Energy cost of VOC Removal increases in the species sequence: dimethyl sulfide, methanol, α-pinene, acetone. It was found that Energy decomposition costs were reduced as temperature and moderate humidity increased.
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experimental assessment of pulsed corona discharge for treatment of voc emissions
Plasma Chemistry and Plasma Processing, 2003Co-Authors: Mario G Sobacchi, Alexei V Saveliev, A F Gutsol, Alexande Fridma, Lawrence A KennedyAbstract:The application of the pulsed corona discharge was experimentally evaluated for the treatment of VOC mixtures typically present in the exhaust streams of wood processing industry. Methanol, acetone, dimethyl sulfide, and α-pinene were selected as representative VOC compounds. An experimental database for the destruction and Removal efficiencies and Energy costs was produced for individual VOCs and their mixtures valid for input concentrations (5 to 1000 ppm), temperatures (25 to 200°C) and relative humidity (0 to 100%). High Removal efficiencies and destruction rates above 99% were obtained with power levels competitive with the present technologies for VOC Removal. Energy cost of VOC Removal increases in the species sequence: dimethyl sulfide, methanol, α-pinene, acetone. It was found that Energy decomposition costs were reduced as temperature and moderate humidity increased.
Patrick Bultinck - One of the best experts on this subject based on the ideXlab platform.
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Exact Ionization Potentials from Wavefunction Asymptotics: The Extended Koopmans' Theorem, Revisited
The Journal of chemical physics, 2009Co-Authors: Diederik Vanfleteren, Paul W Ayers, Robert C Morrison, Dimitri Van Neck, Patrick BultinckAbstract:A simple explanation is given for the exactness of the extended Koopmans' theorem for computing the Removal Energy of any many-electron system to the lowest-Energy ground state ion of a given symmetry. In particular, by removing the electron from a "Removal orbital" of appropriate symmetry that is concentrated in the asymptotic region, one obtains the exact ionization potential and the exact Dyson orbital for the corresponding state of the ion. It is argued that the EKT is not restricted to many-electron systems but holds for any finite many-body system, provided the interaction vanishes for increasing interparticle distance. A necessary and sufficient condition for the validity of the extended Koopmans' theorem for any state (not just the lowest-Energy states of a given symmetry) in terms of the third-order reduced density matrix is stated and derived.
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exact ionization potentials from wavefunction asymptotics the extended koopmans theorem revisited
Journal of Chemical Physics, 2009Co-Authors: Diederik Vanfleteren, Dimitri Van Neck, Paul W Ayers, Robert C Morrison, Patrick BultinckAbstract:A simple explanation is given for the exactness of the extended Koopmans’ theorem, (EKT) for computing the Removal Energy of any many-electron system to the lowest-Energy ground state ion of a given symmetry. In particular, by removing the electron from a “Removal orbital” of appropriate symmetry that is concentrated in the asymptotic region, one obtains the exact ionization potential and the exact Dyson orbital for the corresponding state of the ion. It is argued that the EKT is not restricted to many-electron systems but holds for any finite many-body system, provided that the interaction vanishes for increasing interparticle distance. A necessary and sufficient condition for the validity of the EKT for any state (not just the lowest-Energy states of a given symmetry) in terms of the third-order reduced density matrix is stated and derived.
