Fractures of the humeral paddle, common to young adults, are most often complex, linked to violence and an increase in road accidents. The objective of our work is to evaluate our functional results, in the medium ter...Fractures of the humeral paddle, common to young adults, are most often complex, linked to violence and an increase in road accidents. The objective of our work is to evaluate our functional results, in the medium term, correlated with a review of the literature. This is a retrospective study of 63 patients, carried out in the traumatology-orthopedics department 1 of the IBN EL JAZZAR hospital in KAIROUAN, over a period of 7 years from January 2015 to December 2021. The average age of patients was 39 years (17 - 68 years). Predominantly male. The etiologies are dominated by falls and accidents on public roads. Fractures are classified according to the Müller and Allgöwer classification where type C is found in 51% of cases. All our patients undergo an olecranon osteotomy in 71% of cases. Osteosynthesis using a Lecestre plate combined with screwing or plugging is used in 84% of cases. The evolution is marked by complications observed in eight patients (16%), including two cases of sepsis, four cases of elbow stiffness (8%), one case of joint callus and one case of pseudarthrosis. Our results are evaluated according to the Mayo Elbow Performance Score, they are excellent and good in 71% of cases, average in 18% of cases and poor in 11% of cases. Fractures of the humeral paddle are fractures with a satisfactory functional prognosis, requiring ad integrum anatomical restoration and solid osteosynthesis allowing early rehabilitation of the elbow. One case of joint callus and one case of pseudarthrosis.展开更多
The discrete element method(DEM)and experimental measurements were employed to investigate the influence of impeller rotational speed and paddle angle on the mixing characteristics of two types of non-spherical partic...The discrete element method(DEM)and experimental measurements were employed to investigate the influence of impeller rotational speed and paddle angle on the mixing characteristics of two types of non-spherical particles in a paddle mixer.A close agreement between the simulation and experimental data was observed.By analyzing the motion of particles,it was found that a wide range of diffusion motion occurred when the particles pushed by the paddle blades rolled down the surface of the upper flowing layer of particles in the vessel,which caused the strong circumferential motion of particles,meanwhile promoted the axial movement of particles.The mixing characteristics were analyzed using relative standard deviation(RSD),velocity frequency distribution,diffusivity coefficient and Peclet numbers.The mixing process was accelerated at the rotational speeds of 15,20,and 25 rpm,meanwhile the superior mixing performance was achieved at the paddle angles of 30°and 45°in the study.The fluidity of particles in circumferential direction was higher than that in axial direction.Diffusion was the prevailing mixing mechanism in the current mixing system.展开更多
Normally,small unmanned vessels used to clean floating litter on water adopt a paddle wheel as a propulsor to satisfy its shallow-draft requirements;however,this type of propulsor has bulky structures and inefficient ...Normally,small unmanned vessels used to clean floating litter on water adopt a paddle wheel as a propulsor to satisfy its shallow-draft requirements;however,this type of propulsor has bulky structures and inefficient propulsion.In this study,a novel tandem paddles propulsor(TPP)was developed,and its propulsion performance was analyzed and compared with that of a paddle wheel propulsor(PWP).Using the RNG k-εturbulence model and sliding grid technique,the hydrodynamic performance of the PWP was simulated in computational fluid dynamics(CFD)software to verify the reliability of the numerical method.Subsequently,the propulsion performances of the two types of propulsors were simulated with different immersion depths and advanced coefficients,and the differences in their mechanical characteristics and flow field evolution were discussed and compared.The results indicate that the proposed TPP generates 2.75 times more thrust and 1.99 times greater efficiency than the PWP,exhibiting superior propulsion capability in shallow-draft vessels.展开更多
Many people play table tennis.You can also call it Ping-Pong.It is a fun game.How do you play?You need a table tennis table with a net in the middle.You also need a Ping-Pong ball,some paddles and a friend.First,hit t...Many people play table tennis.You can also call it Ping-Pong.It is a fun game.How do you play?You need a table tennis table with a net in the middle.You also need a Ping-Pong ball,some paddles and a friend.First,hit the ball with your paddle.The ball goes over the net.Then your friend hits it back to you.Then you hit it again.The ball can move quickly!So sometimes you miss it.展开更多
Controlling the size of fragranee microcapsules using designed agitator paddles was investigated and studied by CFD simulation. First, different fluid flows were established by varying stirring speeds, reactor scales,...Controlling the size of fragranee microcapsules using designed agitator paddles was investigated and studied by CFD simulation. First, different fluid flows were established by varying stirring speeds, reactor scales, and agitator paddle design, and the effects of each on particle size and distribution of prepared microcapsules were determined. The experimental results showed that the pattern design of orifices in the plate paddles control the flow field well. Narrow particle-size distributio ns of the microcapsules were obtained. The fluid flow characteristics including fluid velocity field, turbulent kinetic energy field, and shear stress distribution for thedifferent agitator paddle types in different reaction kettles were simulated using CFD tech no logy. The correlations between simulated data and experime ntal results were an alyzed. Significantly, the simulated average flow velocity was found to show good negative linear correlation w让h the average particle size of prepared microcapsules, with a correlation of y =-2.166x + 42.626.展开更多
A double paddle blender's flow patterns and mixing mechanisms were analyzed using discrete element method(DEM)and experiments.The mixing performance of this type of the blender containing bi-disperse particles has...A double paddle blender's flow patterns and mixing mechanisms were analyzed using discrete element method(DEM)and experiments.The mixing performance of this type of the blender containing bi-disperse particles has been rarely studied in the literature.Plackett-Burman design of experiments(DoE)methodology was used to calibrate the DEM input parameters.Subsequently,the impact of the particle number ratio,vessel fill level,and paddle rotational speed on mixing performance was investigated using the calibrated DEM model.The mixing performance was assessed using relative standard deviation and segregation intensity.Mixing performance was significantly affected by the paddle rotational speed and particle number ratio.Moreover,the Peclet number and diffusivity coefficient were used to evaluate the mixing mechanism in the blender.Results revealed that the diffusion was the predominant mixing mechanism,and the best mixing performance was observed when the diffusivity coefficients of 3 mm and 5 mm particles were almost equal.展开更多
JULY 27, 1996. In the women’s kayak pairs at the 1996 Olympic Games in Atlanta, Chinese athletes Cao Mianying and Zhang Xiuyun were still fourth place when approaching the 1,000 meter mark. They creeped to third by 1...JULY 27, 1996. In the women’s kayak pairs at the 1996 Olympic Games in Atlanta, Chinese athletes Cao Mianying and Zhang Xiuyun were still fourth place when approaching the 1,000 meter mark. They creeped to third by 1,500 meters and during the final sprint they beat the Netherlands by a narrow margin to capture the silver.展开更多
Particle suspension and deposition dynamics are significant factors affecting the level of mixing quality in solidliquid two-phase stirring processes. In general, the ability to increase the suspension rate and minimi...Particle suspension and deposition dynamics are significant factors affecting the level of mixing quality in solidliquid two-phase stirring processes. In general, the ability to increase the suspension rate and minimize depositioneffects is instrumental in improving the uniformity of particle mixing, accelerating the reaction of involved solidliquid two-phase, and improving the efficiency of production operations. In this work, suspension and depositionindicator based on the Betti number and a uniformity indicator are introduced and obtained by means of imageanalysis. The influence of the blade type, rotation speed, blade diameter and blade bottom height on the particlesuspension/deposition characteristics and mixing uniformity are carefully investigated. The experimental resultsshow that the two-phase motion region can be divided into three local regions, including a bottom motion alongthe wall, a low-degree suspension region under the blade and a high suspension region above the blade. The bestdegree of particle suspension is attained by the double-inclined blade paddle at a speed of 270 r/min, a paddlediameter ratio of 0.414, and a height-diameter ratio of 0.086. The double-inclined blade paddle has a better effecton promoting particle suspension and solid-liquid two-phase mixing uniformity.展开更多
The emission and contact drying kinetics of the paper mill sludge (PMS) were studied through experiments carried out in a paddle dryer. To get a better understanding of its drying mechanism, a penetration model develo...The emission and contact drying kinetics of the paper mill sludge (PMS) were studied through experiments carried out in a paddle dryer. To get a better understanding of its drying mechanism, a penetration model developed by Tsotsas and Schlünder (1986) was used to simulate the drying kinetics of the PMS. The result indicated that this kinetics could be divided into three phases: pasty, lumpy and granular phases, and could be successfully simulated by the penetration model as the related sludge parameters were integrated into the model. The emission rate curves of the volatile compounds (VCs) were interrelated to the drying rate curve of the PMS, especially for volatile fatty acids (VFAs) and ammonia in this study.展开更多
This paper presents a similitude and computational analysis of the performance of a scaled-down model of a paddle wheel style hydrokinetic generator device used for generating power from the flow of a river. The paddl...This paper presents a similitude and computational analysis of the performance of a scaled-down model of a paddle wheel style hydrokinetic generator device used for generating power from the flow of a river. The paddle wheel dimensions used in this work are one-thirtieth scale of the full-size paddle wheel. The reason for simulating the scaled-down model was to prepare for the testing of a scaled-down physical prototype. Computational Fluid Dynamics using ANSYS Fluent 14.0 software was used for the computational analysis. The scaled-down dimensions were used in the simulations to predict the power that can be generated from the scaled size model of the paddle wheel, having carried out similitude analysis between the scaled down size and its full-size. The dimensionless parameters employed in achieving similitude are the Strouhal number, power coefficient, and pressure coefficient. The power estimation of the full-size was predicted from the scaled size of the paddle wheel based on the similitude analysis.展开更多
A novel binuclear copper (Ⅱ) complex,namely [Cu 2｛Ph 3P(CH 2) 2CO 2｝ 4(NO 3) 2]·(NO 3) 2 1,has been synthesized from the reaction of Cu(NO 3) 2·4H 2O with Ph 3P +(CH 2) 2CO - 2 L.The si...A novel binuclear copper (Ⅱ) complex,namely [Cu 2｛Ph 3P(CH 2) 2CO 2｝ 4(NO 3) 2]·(NO 3) 2 1,has been synthesized from the reaction of Cu(NO 3) 2·4H 2O with Ph 3P +(CH 2) 2CO - 2 L.The single crystal X ray structural analysis of 1 indicates that the compound crystallizes in space group P1(No.2) with a=12.652(3),b=18.983(4),c=9.102(3),α=97.26(2)°,β=107.38(2)°,γ=102.22(2)° and Z=1.In complex 1,a pair of Cu(Ⅱ) atoms are bridged by carboxylate groups of four ligand molecules with a Cu…Cu distance of 2.738 to form a tetrakis (carboxylato O,O) bridge dimetal core,and the apical coordination positions are occupied by monodentate nitrato anions,which is rare in the structures of similar Cu(Ⅱ) complexes in which the apical ligands are usually neutral molecules.The result shows that introducing the anionic ligands into the coordination sphere of the Cu(Ⅱ) atom significantly increases the Cu…Cu distance.展开更多
Aim:Head and neck region reconstructions are often delicate procedures that require different solutions at different layers.The use of chimeric flaps offers the interesting characteristic of combining different tissue...Aim:Head and neck region reconstructions are often delicate procedures that require different solutions at different layers.The use of chimeric flaps offers the interesting characteristic of combining different tissues,which is extremely valuable in this setting.In the present work,we share our experience with different types of conventional flaps,such as the radial flap,the medial sural artery perforator flap,and the fibula osteocutaneous flap.Methods:Over the last year,a series of five patients received advanced head and neck defects reconstruction employing chimeric flaps.The patients included two females and three males,with the mean age of 68-year-old.The defect was in four cases due to radical tumor resection in the oromandibular region.The fifth case was an osteoradionecrosis which needed a complete resection of the affected soft and bony tissue.Results:All five patients were successfully treated.Two of them received a chimeric free flap composed of multiple skin islands while the other three also comprised bone tissue transfer for mandible reconstruction.The mean follow-up period was ten months(range 3-8 months),and during this period neither postoperative complications nor signs of disease relapse were noted.Conclusion:The results obtained resorting to the chimeric fashion of various free flaps suggests that they are an excellent solution from both the functional and aesthetic point of view.Specific technical modifications are proposed according to the case requirements.展开更多
文摘Fractures of the humeral paddle, common to young adults, are most often complex, linked to violence and an increase in road accidents. The objective of our work is to evaluate our functional results, in the medium term, correlated with a review of the literature. This is a retrospective study of 63 patients, carried out in the traumatology-orthopedics department 1 of the IBN EL JAZZAR hospital in KAIROUAN, over a period of 7 years from January 2015 to December 2021. The average age of patients was 39 years (17 - 68 years). Predominantly male. The etiologies are dominated by falls and accidents on public roads. Fractures are classified according to the Müller and Allgöwer classification where type C is found in 51% of cases. All our patients undergo an olecranon osteotomy in 71% of cases. Osteosynthesis using a Lecestre plate combined with screwing or plugging is used in 84% of cases. The evolution is marked by complications observed in eight patients (16%), including two cases of sepsis, four cases of elbow stiffness (8%), one case of joint callus and one case of pseudarthrosis. Our results are evaluated according to the Mayo Elbow Performance Score, they are excellent and good in 71% of cases, average in 18% of cases and poor in 11% of cases. Fractures of the humeral paddle are fractures with a satisfactory functional prognosis, requiring ad integrum anatomical restoration and solid osteosynthesis allowing early rehabilitation of the elbow. One case of joint callus and one case of pseudarthrosis.
基金supported by National Natural Science Foundation of China(grant No.52205261)the 13th Five Years Key Programs for Science and Technology Development of China(grant No.2016YFD0701300).
文摘The discrete element method(DEM)and experimental measurements were employed to investigate the influence of impeller rotational speed and paddle angle on the mixing characteristics of two types of non-spherical particles in a paddle mixer.A close agreement between the simulation and experimental data was observed.By analyzing the motion of particles,it was found that a wide range of diffusion motion occurred when the particles pushed by the paddle blades rolled down the surface of the upper flowing layer of particles in the vessel,which caused the strong circumferential motion of particles,meanwhile promoted the axial movement of particles.The mixing characteristics were analyzed using relative standard deviation(RSD),velocity frequency distribution,diffusivity coefficient and Peclet numbers.The mixing process was accelerated at the rotational speeds of 15,20,and 25 rpm,meanwhile the superior mixing performance was achieved at the paddle angles of 30°and 45°in the study.The fluidity of particles in circumferential direction was higher than that in axial direction.Diffusion was the prevailing mixing mechanism in the current mixing system.
基金supported by the Key R&D Program of Shandong Province,China(Grant No.2021ZLGX04)the National Natural Science Foundation of China(Grant No.52088102)the Shandong Provincial Natural Science Foundation(GrantNo.ZR2022ME147).
文摘Normally,small unmanned vessels used to clean floating litter on water adopt a paddle wheel as a propulsor to satisfy its shallow-draft requirements;however,this type of propulsor has bulky structures and inefficient propulsion.In this study,a novel tandem paddles propulsor(TPP)was developed,and its propulsion performance was analyzed and compared with that of a paddle wheel propulsor(PWP).Using the RNG k-εturbulence model and sliding grid technique,the hydrodynamic performance of the PWP was simulated in computational fluid dynamics(CFD)software to verify the reliability of the numerical method.Subsequently,the propulsion performances of the two types of propulsors were simulated with different immersion depths and advanced coefficients,and the differences in their mechanical characteristics and flow field evolution were discussed and compared.The results indicate that the proposed TPP generates 2.75 times more thrust and 1.99 times greater efficiency than the PWP,exhibiting superior propulsion capability in shallow-draft vessels.
文摘Many people play table tennis.You can also call it Ping-Pong.It is a fun game.How do you play?You need a table tennis table with a net in the middle.You also need a Ping-Pong ball,some paddles and a friend.First,hit the ball with your paddle.The ball goes over the net.Then your friend hits it back to you.Then you hit it again.The ball can move quickly!So sometimes you miss it.
文摘Controlling the size of fragranee microcapsules using designed agitator paddles was investigated and studied by CFD simulation. First, different fluid flows were established by varying stirring speeds, reactor scales, and agitator paddle design, and the effects of each on particle size and distribution of prepared microcapsules were determined. The experimental results showed that the pattern design of orifices in the plate paddles control the flow field well. Narrow particle-size distributio ns of the microcapsules were obtained. The fluid flow characteristics including fluid velocity field, turbulent kinetic energy field, and shear stress distribution for thedifferent agitator paddle types in different reaction kettles were simulated using CFD tech no logy. The correlations between simulated data and experime ntal results were an alyzed. Significantly, the simulated average flow velocity was found to show good negative linear correlation w让h the average particle size of prepared microcapsules, with a correlation of y =-2.166x + 42.626.
文摘A double paddle blender's flow patterns and mixing mechanisms were analyzed using discrete element method(DEM)and experiments.The mixing performance of this type of the blender containing bi-disperse particles has been rarely studied in the literature.Plackett-Burman design of experiments(DoE)methodology was used to calibrate the DEM input parameters.Subsequently,the impact of the particle number ratio,vessel fill level,and paddle rotational speed on mixing performance was investigated using the calibrated DEM model.The mixing performance was assessed using relative standard deviation and segregation intensity.Mixing performance was significantly affected by the paddle rotational speed and particle number ratio.Moreover,the Peclet number and diffusivity coefficient were used to evaluate the mixing mechanism in the blender.Results revealed that the diffusion was the predominant mixing mechanism,and the best mixing performance was observed when the diffusivity coefficients of 3 mm and 5 mm particles were almost equal.
文摘JULY 27, 1996. In the women’s kayak pairs at the 1996 Olympic Games in Atlanta, Chinese athletes Cao Mianying and Zhang Xiuyun were still fourth place when approaching the 1,000 meter mark. They creeped to third by 1,500 meters and during the final sprint they beat the Netherlands by a narrow margin to capture the silver.
基金support from the Yunnan Fundamental Research Project,China(No.202201BE070001-026)Interdisciplinary Research Project of Kunming University of Science and Technology(No.KUST-xk2022001)+2 种基金Yunnan Major Scientific and Technological Projects(No.202302AQ370001-4)Open Foundation of State Environmental Protection Key Laboratory of Mineral Metallurgical Resources Utilization and Pollution Control(No.HB202204)Young Elite Scientist Sponsorship Program by China Association for Science and Technology,China(No.YESS20210106).
文摘Particle suspension and deposition dynamics are significant factors affecting the level of mixing quality in solidliquid two-phase stirring processes. In general, the ability to increase the suspension rate and minimize depositioneffects is instrumental in improving the uniformity of particle mixing, accelerating the reaction of involved solidliquid two-phase, and improving the efficiency of production operations. In this work, suspension and depositionindicator based on the Betti number and a uniformity indicator are introduced and obtained by means of imageanalysis. The influence of the blade type, rotation speed, blade diameter and blade bottom height on the particlesuspension/deposition characteristics and mixing uniformity are carefully investigated. The experimental resultsshow that the two-phase motion region can be divided into three local regions, including a bottom motion alongthe wall, a low-degree suspension region under the blade and a high suspension region above the blade. The bestdegree of particle suspension is attained by the double-inclined blade paddle at a speed of 270 r/min, a paddlediameter ratio of 0.414, and a height-diameter ratio of 0.086. The double-inclined blade paddle has a better effecton promoting particle suspension and solid-liquid two-phase mixing uniformity.
基金Project (No. 2007C03003) supported by the Key Project of Science and Technology of Zhejiang Province, China
文摘The emission and contact drying kinetics of the paper mill sludge (PMS) were studied through experiments carried out in a paddle dryer. To get a better understanding of its drying mechanism, a penetration model developed by Tsotsas and Schlünder (1986) was used to simulate the drying kinetics of the PMS. The result indicated that this kinetics could be divided into three phases: pasty, lumpy and granular phases, and could be successfully simulated by the penetration model as the related sludge parameters were integrated into the model. The emission rate curves of the volatile compounds (VCs) were interrelated to the drying rate curve of the PMS, especially for volatile fatty acids (VFAs) and ammonia in this study.
文摘This paper presents a similitude and computational analysis of the performance of a scaled-down model of a paddle wheel style hydrokinetic generator device used for generating power from the flow of a river. The paddle wheel dimensions used in this work are one-thirtieth scale of the full-size paddle wheel. The reason for simulating the scaled-down model was to prepare for the testing of a scaled-down physical prototype. Computational Fluid Dynamics using ANSYS Fluent 14.0 software was used for the computational analysis. The scaled-down dimensions were used in the simulations to predict the power that can be generated from the scaled size model of the paddle wheel, having carried out similitude analysis between the scaled down size and its full-size. The dimensionless parameters employed in achieving similitude are the Strouhal number, power coefficient, and pressure coefficient. The power estimation of the full-size was predicted from the scaled size of the paddle wheel based on the similitude analysis.
文摘A novel binuclear copper (Ⅱ) complex,namely [Cu 2｛Ph 3P(CH 2) 2CO 2｝ 4(NO 3) 2]·(NO 3) 2 1,has been synthesized from the reaction of Cu(NO 3) 2·4H 2O with Ph 3P +(CH 2) 2CO - 2 L.The single crystal X ray structural analysis of 1 indicates that the compound crystallizes in space group P1(No.2) with a=12.652(3),b=18.983(4),c=9.102(3),α=97.26(2)°,β=107.38(2)°,γ=102.22(2)° and Z=1.In complex 1,a pair of Cu(Ⅱ) atoms are bridged by carboxylate groups of four ligand molecules with a Cu…Cu distance of 2.738 to form a tetrakis (carboxylato O,O) bridge dimetal core,and the apical coordination positions are occupied by monodentate nitrato anions,which is rare in the structures of similar Cu(Ⅱ) complexes in which the apical ligands are usually neutral molecules.The result shows that introducing the anionic ligands into the coordination sphere of the Cu(Ⅱ) atom significantly increases the Cu…Cu distance.
文摘Aim:Head and neck region reconstructions are often delicate procedures that require different solutions at different layers.The use of chimeric flaps offers the interesting characteristic of combining different tissues,which is extremely valuable in this setting.In the present work,we share our experience with different types of conventional flaps,such as the radial flap,the medial sural artery perforator flap,and the fibula osteocutaneous flap.Methods:Over the last year,a series of five patients received advanced head and neck defects reconstruction employing chimeric flaps.The patients included two females and three males,with the mean age of 68-year-old.The defect was in four cases due to radical tumor resection in the oromandibular region.The fifth case was an osteoradionecrosis which needed a complete resection of the affected soft and bony tissue.Results:All five patients were successfully treated.Two of them received a chimeric free flap composed of multiple skin islands while the other three also comprised bone tissue transfer for mandible reconstruction.The mean follow-up period was ten months(range 3-8 months),and during this period neither postoperative complications nor signs of disease relapse were noted.Conclusion:The results obtained resorting to the chimeric fashion of various free flaps suggests that they are an excellent solution from both the functional and aesthetic point of view.Specific technical modifications are proposed according to the case requirements.
