The local chaos characteristics of the time series pressure fluctuations of gas liquid two phase flow in a self aspirated reversed flow jet loop reactor are studied by the deterministic chaos analysis technique. It...The local chaos characteristics of the time series pressure fluctuations of gas liquid two phase flow in a self aspirated reversed flow jet loop reactor are studied by the deterministic chaos analysis technique. It is found that the estimated local largest Lyapunov exponent is positive in all cases and the profile is similar to that of the local fractal dimension in this reactor. The positive largest Lyapunov exponent shows that the reactor is a nonlinear chaotic system. The obvious distribution indicates that the local nonlinear characteristic parameters such as the Lyapunov exponent and the fractal dimension could be applied to further study the flow characteristics such as the flow regine transitions and flow structures of the multi phase reactors.展开更多
Hursts rescaled range (R/S) analysis and Wolfs attractor reconstruction technique have been adopted to estimate the local fractal dimensions and the local largest Lyapunov exponents in terms of the time series pressur...Hursts rescaled range (R/S) analysis and Wolfs attractor reconstruction technique have been adopted to estimate the local fractal dimensions and the local largest Lyapunov exponents in terms of the time series pressure fluctuations obtained from a gas liquid solid three phase self aspirated reversed flow jet loop reactor,respectively.The results indicate that the local fractal dimensions and the local largest Lyapunov exponents in both the jet region and the tubular region inside the draft tube increase with the increase in the jet liquid flowrates and the solid loadings,the local fractal dimension profiles are similar to those of the largest Lyapunov exponent,the local largest lyapunov exponents are positive for all cases,and the flow behavior of such a reactor is chaotic.The local nonlinear characteristic parameters such as the local fractal dimension and the local largest Lyapunov exponent could be applied to further study the flow properties such as the flow regime transitions and flow structures of this three phase jet loop reactor.展开更多
Background: Foreign body aspiration is a common yet preventable health problem. Headscarf pin aspiration is a unique example of aspirated foreign bodies in young Muslim women usually removed using the rigid bronchosco...Background: Foreign body aspiration is a common yet preventable health problem. Headscarf pin aspiration is a unique example of aspirated foreign bodies in young Muslim women usually removed using the rigid bronchoscope. However, the flexible bronchoscope is increasingly used for this purpose. This prospective study was conducted in Sulaimaniyah Teaching Hospital, Sulaimaniyah, Iraq and aimed to evaluate the usefulness of fiberoptic bronchoscope for removal of aspirated headscarf pins in view of the relevant literature. Methodology: Fifty female patients with headscarf pin aspiration were managed by fiberoptic bronchoscopy over an 8-year period (January 2008 to December 2015). The procedure was performed under local anesthesia and conscious sedation through the mouth. Results: The age ranged from 10 to 45 years with a mean of 27.5. All patients had cough, five had unilateral wheeze (10%) while haemoptysis occurred twice (4%). Fiberoptic bronchoscopy succeeded in 45 cases (90%). Rigid bronchoscopy under general anesthesia was necessary in (n = 4, 8%) while one patient (2%) required thoracotomy. ?Conclusion: Fiberoptic bronchoscopy is safe and effective in removal of aspirated headscarf pins and should be tried first.展开更多
Background: Foreign body (FB) aspiration is a common emergency in our practice. The routine method of removal is via rigid bronchoscopy (RB) under general anesthesia. This is the preferred procedure particularly in ch...Background: Foreign body (FB) aspiration is a common emergency in our practice. The routine method of removal is via rigid bronchoscopy (RB) under general anesthesia. This is the preferred procedure particularly in children who form the major affected population. Fiberoptic bronchoscopy (FOB) has also been used for FB removal in many countries, though in Iraq, the standard mean remains rigid bronchoscopy. Objective: Herein, we present 5 cases of FB inhalation in adults in whom FOB was used for removal. The aim is to test its feasibility with literature review. Setting: the department of thoracic surgery/Sulaimania Teaching Hospital/Sulaimania/Iraq. Study Design: a prospective study of 5 patients. Patients and methods: 5 patients (3 females and 2 males) with different bronchial or laryngeal FBs in whom FOB was used as a method for removal are presented. The age ranged from 16 to 71 years. The clinical and radiographic features are recorded. In all these patients, initial FOB examination under local anesthesia transorally or via tracheotomy stoma was done. When removed by this method failed, RB under GA was used and when this failed, thoracotomy was the last resort. Results and Conclusions: FBs encountered in this paper consisted of pins (n = 2), sewing needle (n = 1), speech valve (n = 1) and a medical leach (n = 1). Three FBs (medical leach, speech valve and one pin) were successfully removed by FOB. A pin in RMB was visualized but failed to be removed by FOB and therefore, RB was required for its retrieval, while a needle in left lower lobe was invisible by both FOB and RB and thus surgery was necessary to remove it. We conclude that in adolescent or adult patients with bronchial FBs, FOB should be tried first for removal. If this fails then RB can be used. To increase its success, FOB should be combined with certain accessories like special FB forceps and fluoroscopy.展开更多
文摘The local chaos characteristics of the time series pressure fluctuations of gas liquid two phase flow in a self aspirated reversed flow jet loop reactor are studied by the deterministic chaos analysis technique. It is found that the estimated local largest Lyapunov exponent is positive in all cases and the profile is similar to that of the local fractal dimension in this reactor. The positive largest Lyapunov exponent shows that the reactor is a nonlinear chaotic system. The obvious distribution indicates that the local nonlinear characteristic parameters such as the Lyapunov exponent and the fractal dimension could be applied to further study the flow characteristics such as the flow regine transitions and flow structures of the multi phase reactors.
文摘Hursts rescaled range (R/S) analysis and Wolfs attractor reconstruction technique have been adopted to estimate the local fractal dimensions and the local largest Lyapunov exponents in terms of the time series pressure fluctuations obtained from a gas liquid solid three phase self aspirated reversed flow jet loop reactor,respectively.The results indicate that the local fractal dimensions and the local largest Lyapunov exponents in both the jet region and the tubular region inside the draft tube increase with the increase in the jet liquid flowrates and the solid loadings,the local fractal dimension profiles are similar to those of the largest Lyapunov exponent,the local largest lyapunov exponents are positive for all cases,and the flow behavior of such a reactor is chaotic.The local nonlinear characteristic parameters such as the local fractal dimension and the local largest Lyapunov exponent could be applied to further study the flow properties such as the flow regime transitions and flow structures of this three phase jet loop reactor.
文摘Background: Foreign body aspiration is a common yet preventable health problem. Headscarf pin aspiration is a unique example of aspirated foreign bodies in young Muslim women usually removed using the rigid bronchoscope. However, the flexible bronchoscope is increasingly used for this purpose. This prospective study was conducted in Sulaimaniyah Teaching Hospital, Sulaimaniyah, Iraq and aimed to evaluate the usefulness of fiberoptic bronchoscope for removal of aspirated headscarf pins in view of the relevant literature. Methodology: Fifty female patients with headscarf pin aspiration were managed by fiberoptic bronchoscopy over an 8-year period (January 2008 to December 2015). The procedure was performed under local anesthesia and conscious sedation through the mouth. Results: The age ranged from 10 to 45 years with a mean of 27.5. All patients had cough, five had unilateral wheeze (10%) while haemoptysis occurred twice (4%). Fiberoptic bronchoscopy succeeded in 45 cases (90%). Rigid bronchoscopy under general anesthesia was necessary in (n = 4, 8%) while one patient (2%) required thoracotomy. ?Conclusion: Fiberoptic bronchoscopy is safe and effective in removal of aspirated headscarf pins and should be tried first.
文摘Background: Foreign body (FB) aspiration is a common emergency in our practice. The routine method of removal is via rigid bronchoscopy (RB) under general anesthesia. This is the preferred procedure particularly in children who form the major affected population. Fiberoptic bronchoscopy (FOB) has also been used for FB removal in many countries, though in Iraq, the standard mean remains rigid bronchoscopy. Objective: Herein, we present 5 cases of FB inhalation in adults in whom FOB was used for removal. The aim is to test its feasibility with literature review. Setting: the department of thoracic surgery/Sulaimania Teaching Hospital/Sulaimania/Iraq. Study Design: a prospective study of 5 patients. Patients and methods: 5 patients (3 females and 2 males) with different bronchial or laryngeal FBs in whom FOB was used as a method for removal are presented. The age ranged from 16 to 71 years. The clinical and radiographic features are recorded. In all these patients, initial FOB examination under local anesthesia transorally or via tracheotomy stoma was done. When removed by this method failed, RB under GA was used and when this failed, thoracotomy was the last resort. Results and Conclusions: FBs encountered in this paper consisted of pins (n = 2), sewing needle (n = 1), speech valve (n = 1) and a medical leach (n = 1). Three FBs (medical leach, speech valve and one pin) were successfully removed by FOB. A pin in RMB was visualized but failed to be removed by FOB and therefore, RB was required for its retrieval, while a needle in left lower lobe was invisible by both FOB and RB and thus surgery was necessary to remove it. We conclude that in adolescent or adult patients with bronchial FBs, FOB should be tried first for removal. If this fails then RB can be used. To increase its success, FOB should be combined with certain accessories like special FB forceps and fluoroscopy.
