We report the structural, optical and electrical properties of Graphene-Vanadium oxide nanoparticles (rGO/VO-NPs) nanocomposites prepared via a hydrothermal method on glass substrates. The samples have been characteri...We report the structural, optical and electrical properties of Graphene-Vanadium oxide nanoparticles (rGO/VO-NPs) nanocomposites prepared via a hydrothermal method on glass substrates. The samples have been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, ultraviolet-visible spectra (Uv-Vis) (absorbance/reflectance) and electrical conductivity. Our results are revealing a remarkable effect on the morphology and structure of vanadium oxide nanoparticles. Hence, the graphene layers improved their electrical conductivity and highly influenced their optical properties. Therefore, the obtained results may lead to better performance for a large field of applications.展开更多
A high temperature superconducting(HTS)magnetically levitated testbed has been developed for the steady thrust measurement of miniature ion electrospray thruster.The structure of the testbed mainly consists of an HTS ...A high temperature superconducting(HTS)magnetically levitated testbed has been developed for the steady thrust measurement of miniature ion electrospray thruster.The structure of the testbed mainly consists of an HTS composite bearing,a magnetic shielding plate,an active electromagnetic brake and a laser displacement sensor.The steady thrust is described as a function of the equilibrium angle displacement of the floating frame.Furthermore,the mechanical behaviors of HTS composite bearing were studied via finite element simulation and experiments,which include the load capacity,levitation stiffness and background noise.The results show that the thrust testbed can keep in low noise and have a load capacity up to 4 kg.According to the ignition testing of the electrospray thruster,the thrust force of 25.2 m N was measured by the testbed,which is close to the design value of miniature ion electrospray thruster.展开更多
We investigated the magnetocaloric effect in commercial Er_(2)O_(3) powders which presents almost no hysteresis losses at low temperature.At a magnetic field change of 5 T,it displays large magnetic entropy change(-Δ...We investigated the magnetocaloric effect in commercial Er_(2)O_(3) powders which presents almost no hysteresis losses at low temperature.At a magnetic field change of 5 T,it displays large magnetic entropy change(-ΔSM)max of 15.02 J/(kg·K)and a refrigerant capacity(RC)of 311 J/K at Neel temperature TN=3.32 K.The magnetic transition was found to be of a second-order.The maximum values of adiabatic temperature change(ΔTad)max reach 0.70 K for a magnetic field change of 1 T.The large value,of(-ASM)max as well as no hysteresis loss,makes Er_(2)O_(3) a promising material as a magnetic refrigerant at low temperature.展开更多
Efficient solvers for optimization problems are based on linear and semidefinite relaxations that use floating point arithmetic. However, due to the rounding errors, relaxation thus may overestimate, or worst, underes...Efficient solvers for optimization problems are based on linear and semidefinite relaxations that use floating point arithmetic. However, due to the rounding errors, relaxation thus may overestimate, or worst, underestimate the very global optima. The purpose of this article is to introduce an efficient and safe procedure to rigorously bound the global optima of semidefinite program. This work shows how, using interval arithmetic, rigorous error bounds for the optimal value can be computed by carefully post processing the output of a semidefinite programming solver. A lower bound is computed on a semidefinite relaxation of the constraint system and the objective function. Numerical results are presented using the SDPA (SemiDefinite Programming Algorithm), solver to compute the solution of semidefinite programs. This rigorous bound is injected in a branch and bound algorithm to solve the optimisation problem.展开更多
Background: Colchicine intoxication is uncommon but potentially life threatening because of the high toxicity of the drug. Colchicine binds to the intracellular protein tubulin, causing disturbed mitosis in all tissue...Background: Colchicine intoxication is uncommon but potentially life threatening because of the high toxicity of the drug. Colchicine binds to the intracellular protein tubulin, causing disturbed mitosis in all tissues followed by multi-organ failure. Case Presentation: We report a case of a 23-year-old woman admitted to emergency room 12 hours after a suicide attempt by ingestion of approximatively 40 mg of colchicine. Few hours after consumption, first symptoms were a hemodynamic shock and ARDS, leading to her death due to multi-organ failure. Conclusion: The colchicine intoxication has strong morbidity for doses higher than 0.5 mg/kg. The treatment is symptomatic. The immunotherapy using anti-colchicine allows improving critical form’s prognosis.展开更多
Background: Pneumomediastinum and subcutaneous emphysema are a rare and well-known complication of dental procedures. Many cases go unrecognized and resolve spontaneously, while others may require specific therapeutic...Background: Pneumomediastinum and subcutaneous emphysema are a rare and well-known complication of dental procedures. Many cases go unrecognized and resolve spontaneously, while others may require specific therapeutic management to prevent complications. Case Presentations: We report a case of cervical subcutaneous emphysema and pneumomediasitnum occurring after extraction of lower right second molar. The emphysema was detected 2 hours after dental surgery. This paper reports on the diagnosis and treatment of subcutaneous emphysema and pneumomediastinum. Conclusion: In order to prevent this complication, air turbine high speed drills should be used only in necessary cases.展开更多
文摘We report the structural, optical and electrical properties of Graphene-Vanadium oxide nanoparticles (rGO/VO-NPs) nanocomposites prepared via a hydrothermal method on glass substrates. The samples have been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, ultraviolet-visible spectra (Uv-Vis) (absorbance/reflectance) and electrical conductivity. Our results are revealing a remarkable effect on the morphology and structure of vanadium oxide nanoparticles. Hence, the graphene layers improved their electrical conductivity and highly influenced their optical properties. Therefore, the obtained results may lead to better performance for a large field of applications.
文摘A high temperature superconducting(HTS)magnetically levitated testbed has been developed for the steady thrust measurement of miniature ion electrospray thruster.The structure of the testbed mainly consists of an HTS composite bearing,a magnetic shielding plate,an active electromagnetic brake and a laser displacement sensor.The steady thrust is described as a function of the equilibrium angle displacement of the floating frame.Furthermore,the mechanical behaviors of HTS composite bearing were studied via finite element simulation and experiments,which include the load capacity,levitation stiffness and background noise.The results show that the thrust testbed can keep in low noise and have a load capacity up to 4 kg.According to the ignition testing of the electrospray thruster,the thrust force of 25.2 m N was measured by the testbed,which is close to the design value of miniature ion electrospray thruster.
文摘We investigated the magnetocaloric effect in commercial Er_(2)O_(3) powders which presents almost no hysteresis losses at low temperature.At a magnetic field change of 5 T,it displays large magnetic entropy change(-ΔSM)max of 15.02 J/(kg·K)and a refrigerant capacity(RC)of 311 J/K at Neel temperature TN=3.32 K.The magnetic transition was found to be of a second-order.The maximum values of adiabatic temperature change(ΔTad)max reach 0.70 K for a magnetic field change of 1 T.The large value,of(-ASM)max as well as no hysteresis loss,makes Er_(2)O_(3) a promising material as a magnetic refrigerant at low temperature.
文摘Efficient solvers for optimization problems are based on linear and semidefinite relaxations that use floating point arithmetic. However, due to the rounding errors, relaxation thus may overestimate, or worst, underestimate the very global optima. The purpose of this article is to introduce an efficient and safe procedure to rigorously bound the global optima of semidefinite program. This work shows how, using interval arithmetic, rigorous error bounds for the optimal value can be computed by carefully post processing the output of a semidefinite programming solver. A lower bound is computed on a semidefinite relaxation of the constraint system and the objective function. Numerical results are presented using the SDPA (SemiDefinite Programming Algorithm), solver to compute the solution of semidefinite programs. This rigorous bound is injected in a branch and bound algorithm to solve the optimisation problem.
文摘Background: Colchicine intoxication is uncommon but potentially life threatening because of the high toxicity of the drug. Colchicine binds to the intracellular protein tubulin, causing disturbed mitosis in all tissues followed by multi-organ failure. Case Presentation: We report a case of a 23-year-old woman admitted to emergency room 12 hours after a suicide attempt by ingestion of approximatively 40 mg of colchicine. Few hours after consumption, first symptoms were a hemodynamic shock and ARDS, leading to her death due to multi-organ failure. Conclusion: The colchicine intoxication has strong morbidity for doses higher than 0.5 mg/kg. The treatment is symptomatic. The immunotherapy using anti-colchicine allows improving critical form’s prognosis.
文摘Background: Pneumomediastinum and subcutaneous emphysema are a rare and well-known complication of dental procedures. Many cases go unrecognized and resolve spontaneously, while others may require specific therapeutic management to prevent complications. Case Presentations: We report a case of cervical subcutaneous emphysema and pneumomediasitnum occurring after extraction of lower right second molar. The emphysema was detected 2 hours after dental surgery. This paper reports on the diagnosis and treatment of subcutaneous emphysema and pneumomediastinum. Conclusion: In order to prevent this complication, air turbine high speed drills should be used only in necessary cases.
