Recently, damage caused by liquid droplet impingement erosion (LDIE) in addition to flow-accelerated corrosion (FAC) has frequently occurred in the secondary side steam piping of nuclear power plants, and the damage-o...Recently, damage caused by liquid droplet impingement erosion (LDIE) in addition to flow-accelerated corrosion (FAC) has frequently occurred in the secondary side steam piping of nuclear power plants, and the damage-occurring frequency is expected to increase as their operating years’ increase. In order to scrutinize its causes, therefore, an experimental study was conducted to understand how the behavior of LDIE-FAC multiple degradation changes when the piping of nuclear power plants is operated for a long time. Experimental results show that more magnetite was formed on the surface of the carbon steel specimen than on the low-alloy steel specimen, and that the rate of magnetite formation and extinction reached equilibrium due to the complex action of liquid droplet impingement erosion and flow-accelerated corrosion after a certain period of time. Furthermore, it was confirmed at the beginning of the experiment that A106 Gr.B specimen has more mass loss than A335 P22 specimen. After a certain period of time, however, the mass loss tends to be the opposite. This is presumed to have resulted from the magnetite formed on the surface playing a role in suppressing liquid droplet impingement erosion. In addition, it was confirmed that the amount of erosion linearly increases under the conditions in which the formation and extinction of magnetite reach equilibrium.展开更多
We report here a case of an inflammatory myofibroblastic tumor in the retroperitoneum, which mimicked a germ cell tumor of the undescended testis. A 75-year-old healthy man presented with a palpable abdominal mass. On...We report here a case of an inflammatory myofibroblastic tumor in the retroperitoneum, which mimicked a germ cell tumor of the undescended testis. A 75-year-old healthy man presented with a palpable abdominal mass. On the computed tomography image, there was large, well-defined soft tissue mass in the left side of the retroperitoneum, and there was no visible left testis or seminal vesicle. After contrast enhancement, the mass appeared to be relatively homogeneous, considering its large size. With ultrasonography, it appeared as a well-defined, hypoechoic mass with intratumoral vascularity. This solid mass was surgically diagnosed as an inflammatory myofibroblastic tumor.展开更多
BACKGROUND:Adequate airway management plays an important role in high-quality cardiopulmonary resuscitation(CPR).Airway management is usually performed using an endotracheal tube(ETT)during CPR.However,no study has as...BACKGROUND:Adequate airway management plays an important role in high-quality cardiopulmonary resuscitation(CPR).Airway management is usually performed using an endotracheal tube(ETT)during CPR.However,no study has assessed the effect of ETT size on the fl ow rate and airway pressure during CPR.METHODS:We measured changes in peak inspiratory fl ow rate(PIFR),peak airway pressure(Ppeak),and mean airway pressure(Pmean)according to changes in ETT size(internal diameter 6.0,7.0,and 8.0 mm)and with or without CPR.A tidal volume of 500 mL was supplied at a rate of 10 times per minute using a mechanical ventilator.Chest compressions were maintained at a constant compression depth and speed using a mechanical chest compression device(LUCAS2,mode:active continuous,chest compression rate:102±2/minute,chest compression depth 2–2.5 inches).RESULTS:The median of several respiratory physiological parameters during CPR was significantly different according to the diameter of each ETT(6.0 vs.8.0 mm):PIFR(32.1 L/min[30.5–35.3]vs.28.9 L/min[27.5–30.8],P<0.001),Ppeak(48.84 cmH2O[27.46–52.11]vs.27.45 cmH2O[22.53–52.57],P<0.001),and Pmean(18.34 cmH2O[14.61–21.66]vs.13.66 cmH2O[8.41–19.24],P<0.001).CONCLUSION:The changes in PIFR,Ppeak,and Pmean were related to the internal diameter of ETT,and these values tended to decrease with an increase in ETT size.Higher airway pressures were measured in the CPR group than in the no CPR group.展开更多
文摘Recently, damage caused by liquid droplet impingement erosion (LDIE) in addition to flow-accelerated corrosion (FAC) has frequently occurred in the secondary side steam piping of nuclear power plants, and the damage-occurring frequency is expected to increase as their operating years’ increase. In order to scrutinize its causes, therefore, an experimental study was conducted to understand how the behavior of LDIE-FAC multiple degradation changes when the piping of nuclear power plants is operated for a long time. Experimental results show that more magnetite was formed on the surface of the carbon steel specimen than on the low-alloy steel specimen, and that the rate of magnetite formation and extinction reached equilibrium due to the complex action of liquid droplet impingement erosion and flow-accelerated corrosion after a certain period of time. Furthermore, it was confirmed at the beginning of the experiment that A106 Gr.B specimen has more mass loss than A335 P22 specimen. After a certain period of time, however, the mass loss tends to be the opposite. This is presumed to have resulted from the magnetite formed on the surface playing a role in suppressing liquid droplet impingement erosion. In addition, it was confirmed that the amount of erosion linearly increases under the conditions in which the formation and extinction of magnetite reach equilibrium.
文摘We report here a case of an inflammatory myofibroblastic tumor in the retroperitoneum, which mimicked a germ cell tumor of the undescended testis. A 75-year-old healthy man presented with a palpable abdominal mass. On the computed tomography image, there was large, well-defined soft tissue mass in the left side of the retroperitoneum, and there was no visible left testis or seminal vesicle. After contrast enhancement, the mass appeared to be relatively homogeneous, considering its large size. With ultrasonography, it appeared as a well-defined, hypoechoic mass with intratumoral vascularity. This solid mass was surgically diagnosed as an inflammatory myofibroblastic tumor.
基金supported by the Chungnam National University Hospital Research Fund,2016
文摘BACKGROUND:Adequate airway management plays an important role in high-quality cardiopulmonary resuscitation(CPR).Airway management is usually performed using an endotracheal tube(ETT)during CPR.However,no study has assessed the effect of ETT size on the fl ow rate and airway pressure during CPR.METHODS:We measured changes in peak inspiratory fl ow rate(PIFR),peak airway pressure(Ppeak),and mean airway pressure(Pmean)according to changes in ETT size(internal diameter 6.0,7.0,and 8.0 mm)and with or without CPR.A tidal volume of 500 mL was supplied at a rate of 10 times per minute using a mechanical ventilator.Chest compressions were maintained at a constant compression depth and speed using a mechanical chest compression device(LUCAS2,mode:active continuous,chest compression rate:102±2/minute,chest compression depth 2–2.5 inches).RESULTS:The median of several respiratory physiological parameters during CPR was significantly different according to the diameter of each ETT(6.0 vs.8.0 mm):PIFR(32.1 L/min[30.5–35.3]vs.28.9 L/min[27.5–30.8],P<0.001),Ppeak(48.84 cmH2O[27.46–52.11]vs.27.45 cmH2O[22.53–52.57],P<0.001),and Pmean(18.34 cmH2O[14.61–21.66]vs.13.66 cmH2O[8.41–19.24],P<0.001).CONCLUSION:The changes in PIFR,Ppeak,and Pmean were related to the internal diameter of ETT,and these values tended to decrease with an increase in ETT size.Higher airway pressures were measured in the CPR group than in the no CPR group.
