A one-dimensional unsteady mathematical model was established to describe direct reduction in a composite pellet made of metallurgical dust. The model considered heat transfer, mass transfer, and chemical reactions in...A one-dimensional unsteady mathematical model was established to describe direct reduction in a composite pellet made of metallurgical dust. The model considered heat transfer, mass transfer, and chemical reactions including iron oxide reductions, zinc oxide reduction and carbon gasification, and it was numerically solved by the tridiagonal matrix algorithm （TDMA）. In order to verify the model, an experiment was performed, in which the profiles of temperature and zinc removal rate were measured during the reduction process. Results calculated by the mathematical model were in fairly good agreement with experimental data. Finally, the effects of furnace temperature, pellet size, and carbon content were investigated by model calculations. It is found that the pellet temperature curve can be divided into four parts according to heating rate. Also, the zinc removal rate increases with the increase of furnace temperature and the decrease of pellet size, and carbon content in the pellet has little influence on the zinc removal rate.展开更多
BACKGROUND Primary intestinal lymphangiectasia(PIL)is a rare protein-losing enteropathy characterized by abnormally dilated lymphatic structures,resulting in leakage of lymph(rich in protein,lymphocytes,and fat)from t...BACKGROUND Primary intestinal lymphangiectasia(PIL)is a rare protein-losing enteropathy characterized by abnormally dilated lymphatic structures,resulting in leakage of lymph(rich in protein,lymphocytes,and fat)from the intestinal mucosal and submucosal layers and thus hypoproteinemia,lymphopenia,hypolipidemia,and pleural effusion.CASE SUMMARY A 19-year-old Chinese male patient complained of recurrent limb convulsions for the last 1 year.Laboratory investigations revealed low levels of calcium and magnesium along with hypoproteinemia and high parathyroid hormone levels,whereas gastroscopy exhibited chronic non-atrophic gastritis and duodenal lymphatic dilatation.Subsequent gastric biopsy showed moderate chronic inflammatory cell infiltration distributed around a small mucosal patch in the descending duodenum followed by lymphatic dilatation in the mucosal lamina propria,which was later diagnosed as PIL.The following appropriate mediumchain triglycerides nutritional support significantly improved the patient’s symptoms.CONCLUSION Since several diseases mimic the clinical symptoms displayed by PIL,like limb convulsions,low calcium and magnesium,and loss of plasma proteins,it is imperative to conduct a detailed analysis to avoid any misdiagnosis while pinpointing the correct clinical diagnosis and simultaneously ruling out other clinical aspects in the reported cases without any past disease history.A careful assessment should always be made to ensure an accurate diagnosis in a timely manner so that the patient can be delivered quality health services for a positive health outcome.展开更多
基金the Fundamen-tal Research Funds for Central Universities(No.FRF-SD-12-013A)the State Key Laboratory of Advanced Metallurgy,China
文摘A one-dimensional unsteady mathematical model was established to describe direct reduction in a composite pellet made of metallurgical dust. The model considered heat transfer, mass transfer, and chemical reactions including iron oxide reductions, zinc oxide reduction and carbon gasification, and it was numerically solved by the tridiagonal matrix algorithm （TDMA）. In order to verify the model, an experiment was performed, in which the profiles of temperature and zinc removal rate were measured during the reduction process. Results calculated by the mathematical model were in fairly good agreement with experimental data. Finally, the effects of furnace temperature, pellet size, and carbon content were investigated by model calculations. It is found that the pellet temperature curve can be divided into four parts according to heating rate. Also, the zinc removal rate increases with the increase of furnace temperature and the decrease of pellet size, and carbon content in the pellet has little influence on the zinc removal rate.
文摘BACKGROUND Primary intestinal lymphangiectasia(PIL)is a rare protein-losing enteropathy characterized by abnormally dilated lymphatic structures,resulting in leakage of lymph(rich in protein,lymphocytes,and fat)from the intestinal mucosal and submucosal layers and thus hypoproteinemia,lymphopenia,hypolipidemia,and pleural effusion.CASE SUMMARY A 19-year-old Chinese male patient complained of recurrent limb convulsions for the last 1 year.Laboratory investigations revealed low levels of calcium and magnesium along with hypoproteinemia and high parathyroid hormone levels,whereas gastroscopy exhibited chronic non-atrophic gastritis and duodenal lymphatic dilatation.Subsequent gastric biopsy showed moderate chronic inflammatory cell infiltration distributed around a small mucosal patch in the descending duodenum followed by lymphatic dilatation in the mucosal lamina propria,which was later diagnosed as PIL.The following appropriate mediumchain triglycerides nutritional support significantly improved the patient’s symptoms.CONCLUSION Since several diseases mimic the clinical symptoms displayed by PIL,like limb convulsions,low calcium and magnesium,and loss of plasma proteins,it is imperative to conduct a detailed analysis to avoid any misdiagnosis while pinpointing the correct clinical diagnosis and simultaneously ruling out other clinical aspects in the reported cases without any past disease history.A careful assessment should always be made to ensure an accurate diagnosis in a timely manner so that the patient can be delivered quality health services for a positive health outcome.
