The Experts below are selected from a list of 225 Experts worldwide ranked by ideXlab platform
Yong Zhou - One of the best experts on this subject based on the ideXlab platform.
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Why did World Trade Center collapse?: Simple analysis
Archive of Applied Mechanics (Ingenieur Archiv), 2001Co-Authors: Zdenek P. Bazant, Yong ZhouAbstract:Simplified approximate analysis of the overall collapse of the World Trade Center towers is presented. It is shown that if Prolonged Heating causes the majority of columns of a single floor to lose their load-carrying capacity, the whole tower is doomed.
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WHY DID THE WORLD TRADE CENTER COLLAPSE? — SIMPLE ANALYSIS
International Journal of Structural Stability and Dynamics, 2001Co-Authors: Zdenek P. Bazant, Yong ZhouAbstract:This paper presents a simplified approximate analysis of the overall collapse of the towers of World Trade Center in New York on September 11, 2001. The analysis shows that if Prolonged Heating caused the majority of columns of a single floor to lose their load carrying capacity, the whole tower was doomed. Despite optimistic simplifying assumptions, the structural resistance is found to be an order of magnitude less than necessary for survival.
Sang Won Jeong - One of the best experts on this subject based on the ideXlab platform.
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Prolonged Heating of fe3o4 au hybrid nanoparticles in a radiofrequency solenoid coil
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2018Co-Authors: Sang Im Park, Seok Hwan Chung, Hyun-chul Kim, Seong Jun Lee, Hyunmin Kim, Ho Young Kim, Se Geun Lee, Sang Won JeongAbstract:Abstract We report the hyperthermia properties of Fe3O4–Au hybrid nanoparticles (HNPs) under a biocompatible alternating magnetic field (AMF) of 1.5 kA m−1 and 200 kHz. The HNPs were prepared by growing Au nanoparticles (AuNPs) with an average diameter of 3 nm on the surface of Fe3O4 magnetic nanoparticles (MNPs) with an average diameter of 10 nm. The structural properties were determined by transmission electron microscopy (TEM), dynamic light scattering (DLS), and X-ray diffraction (XRD). Under the AMF, the initial Heating rate of the HNPs solution was lower than that of the MNPs solution because HNPs have a reduced saturation magnetization (Ms) value compared to MNPs. The continued AMF application increased the temperature of the HNPs solution steadily while the MNPs solution reached a thermal equilibrium. The Heating effect of AuNPs conjugated to diamagnetic and non-conductive SiO2 nanoparticles (SiO2-AuNPs) was demonstrated under the same AMF condition, which suggests that the Prolonged Heating of HNPs can be attributed to the additional Heating of AuNPs in the radiofrequency (RF) solenoid coil.
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Prolonged Heating of Fe3O4–Au hybrid nanoparticles in a radiofrequency solenoid coil
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2018Co-Authors: Sang Im Park, Seok Hwan Chung, Hyun-chul Kim, Geun Lee, Seong Jun Lee, Hyunmin Kim, Ho Young Kim, Sang Won JeongAbstract:Abstract We report the hyperthermia properties of Fe3O4–Au hybrid nanoparticles (HNPs) under a biocompatible alternating magnetic field (AMF) of 1.5 kA m−1 and 200 kHz. The HNPs were prepared by growing Au nanoparticles (AuNPs) with an average diameter of 3 nm on the surface of Fe3O4 magnetic nanoparticles (MNPs) with an average diameter of 10 nm. The structural properties were determined by transmission electron microscopy (TEM), dynamic light scattering (DLS), and X-ray diffraction (XRD). Under the AMF, the initial Heating rate of the HNPs solution was lower than that of the MNPs solution because HNPs have a reduced saturation magnetization (Ms) value compared to MNPs. The continued AMF application increased the temperature of the HNPs solution steadily while the MNPs solution reached a thermal equilibrium. The Heating effect of AuNPs conjugated to diamagnetic and non-conductive SiO2 nanoparticles (SiO2-AuNPs) was demonstrated under the same AMF condition, which suggests that the Prolonged Heating of HNPs can be attributed to the additional Heating of AuNPs in the radiofrequency (RF) solenoid coil.
Zdenek P. Bazant - One of the best experts on this subject based on the ideXlab platform.
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Why did World Trade Center collapse?: Simple analysis
Archive of Applied Mechanics (Ingenieur Archiv), 2001Co-Authors: Zdenek P. Bazant, Yong ZhouAbstract:Simplified approximate analysis of the overall collapse of the World Trade Center towers is presented. It is shown that if Prolonged Heating causes the majority of columns of a single floor to lose their load-carrying capacity, the whole tower is doomed.
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WHY DID THE WORLD TRADE CENTER COLLAPSE? — SIMPLE ANALYSIS
International Journal of Structural Stability and Dynamics, 2001Co-Authors: Zdenek P. Bazant, Yong ZhouAbstract:This paper presents a simplified approximate analysis of the overall collapse of the towers of World Trade Center in New York on September 11, 2001. The analysis shows that if Prolonged Heating caused the majority of columns of a single floor to lose their load carrying capacity, the whole tower was doomed. Despite optimistic simplifying assumptions, the structural resistance is found to be an order of magnitude less than necessary for survival.
F.Ö Orhaner - One of the best experts on this subject based on the ideXlab platform.
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Effect of Prolonged Heating at 130°C on fatigue crack propagation of 2024 Al alloy in three orientations
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 1998Co-Authors: F Sarioğlu, F.Ö OrhanerAbstract:Abstract An Al–Cu alloy 2024 received in T3 condition (cold worked after solutionizing and natural aging) was heated at 130°C for 100 and 1000 h. Fatigue crack growth tests were carried out before and after Heating with center cracked tension specimens machined in L – T , T – L and 60° orientations. Fracture surfaces were studied by means of scanning electron microscopy. It was found that the fatigue crack growth rate depends on the test direction in T3 condition. The orientation effect seemed to be lost after Prolonged Heating at 130°C.
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effect of Prolonged Heating at 130 c on fatigue crack propagation of 2024 al alloy in three orientations
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 1998Co-Authors: F Sarioğlu, F.Ö OrhanerAbstract:Abstract An Al–Cu alloy 2024 received in T3 condition (cold worked after solutionizing and natural aging) was heated at 130°C for 100 and 1000 h. Fatigue crack growth tests were carried out before and after Heating with center cracked tension specimens machined in L – T , T – L and 60° orientations. Fracture surfaces were studied by means of scanning electron microscopy. It was found that the fatigue crack growth rate depends on the test direction in T3 condition. The orientation effect seemed to be lost after Prolonged Heating at 130°C.
Pejman Ghanouni - One of the best experts on this subject based on the ideXlab platform.
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Prolonged Heating in nontargeted tissue during MR‐guided focused ultrasound of bone tumors
Journal of magnetic resonance imaging : JMRI, 2019Co-Authors: Rachel R. Bitton, Kim Butts Pauly, Taylor Webb, Pejman GhanouniAbstract:BACKGROUND Thermal dosimetry during MR-guided focused ultrasound (MRgFUS) of bone tumors underpredicts ablation zone. Intraprocedural understanding of heat accumulation near bone is needed to prevent undesired treatment of nontargeted tissue. HYPOTHESIS Temperature decay rates predict Prolonged, spatially varying Heating during MRgFUS bone treatments. STUDY TYPE Prospective case series. PATIENTS Nine patients with localized painful bone tumors (five bone metastasis, four osteoid osteomas), were compared with five patients with uterine fibroid tumors treated using MRgFUS. FIELD STRENGTH/SEQUENCE Proton resonance frequency shift thermometry using 2D-GRE with echo-planar imaging at 3 T. ASSESSMENT Tissue response was derived by fitting data from extended thermometry acquisitions to a decay model. Decay rates and time to peak temperature (TTP) were analyzed in segmented zones between the bone target and skin. Decay rates were used to calculate intersonication cooling times required to return to body temperature; these were compared against conventional system-mandated cooling times. STATISTICAL TESTS Kolmogorov-Smirnov tests for normality, and Student's t-test was used to compare decay rates. Spatial TTP delay and predicted cooling times used Wilcoxon signed rank tests. P
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Prolonged Heating in nontargeted tissue during mr guided focused ultrasound of bone tumors
Journal of Magnetic Resonance Imaging, 2019Co-Authors: Rachel R. Bitton, Kim Butts Pauly, Taylor Webb, Pejman GhanouniAbstract:BACKGROUND Thermal dosimetry during MR-guided focused ultrasound (MRgFUS) of bone tumors underpredicts ablation zone. Intraprocedural understanding of heat accumulation near bone is needed to prevent undesired treatment of nontargeted tissue. HYPOTHESIS Temperature decay rates predict Prolonged, spatially varying Heating during MRgFUS bone treatments. STUDY TYPE Prospective case series. PATIENTS Nine patients with localized painful bone tumors (five bone metastasis, four osteoid osteomas), were compared with five patients with uterine fibroid tumors treated using MRgFUS. FIELD STRENGTH/SEQUENCE Proton resonance frequency shift thermometry using 2D-GRE with echo-planar imaging at 3 T. ASSESSMENT Tissue response was derived by fitting data from extended thermometry acquisitions to a decay model. Decay rates and time to peak temperature (TTP) were analyzed in segmented zones between the bone target and skin. Decay rates were used to calculate intersonication cooling times required to return to body temperature; these were compared against conventional system-mandated cooling times. STATISTICAL TESTS Kolmogorov-Smirnov tests for normality, and Student's t-test was used to compare decay rates. Spatial TTP delay and predicted cooling times used Wilcoxon signed rank tests. P < 0.05 was significant. RESULTS Tissue decay rates in bone tumor patients were 3.5 times slower than those in patients with fibroids (τbone = 0.037 ± 0.012 vs. τfibroid = 0.131 ± 0.010, P < 0.05). Spatial analysis showed slow decay rates effecting baseline temperature as far as 12 mm away from the bone surface, τ4 = 0.015 ± 0.026 (median ± interquartile range [IQR]). Tissue within 9 mm of bone experienced delayed TTP (P < 0.01). In the majority of bone tumor treatments, system-predicted intersonication cooling times were insufficient for nearby tissue to return to body temperature (P = 0.03 in zone 4). DATA CONCLUSION MRgFUS near bone is susceptible to long tissue decay rates, and unwanted cumulative Heating up to 1.2 cm from the surface of the bone. Knowledge of decay rates may be used to alter treatment planning and intraprocedural thermal monitoring protocols to account for Prolonged Heating by bone. LEVEL OF EVIDENCE 4 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2019;50:1526-1533.
