In this study,a computational fluid dynamics(CFD)method was adopted to calculate axial dispersion coefficients of annular pulsed disc and doughnut columns(APDDCs).Passive tracer was uniformly injected by pulse input a...In this study,a computational fluid dynamics(CFD)method was adopted to calculate axial dispersion coefficients of annular pulsed disc and doughnut columns(APDDCs).Passive tracer was uniformly injected by pulse input at the continuous phase inlet,and its concentration governing equation was solved in liquid–liquidtwo-phase flow fields.The residence time distributions(RTDs)were obtained using the surface monitoring technique.The adopted RTD–CFD method was verified by comparing the axial dispersion coefficient between simulation and experimental results in the literature.However,in pilot-scale APDDCs,the axial dispersion coefficients predicted by the CFD–RTD method were approximately three times larger than experimental results determined by the steady-state concentration profile method.This experimental method was demonstrated to be insensitive to the variation of the axial dispersion coefficient.The CFD–RTD method was more recommended to determine the axial dispersion coefficient.It was found that the axial dispersion coefficient increased with an increase in pulsation intensity,column diameter,and plate spacing,but was little affected by the throughput.展开更多
Purpose: Doughnut mastopexy lumpectomy (DML) is a breast resection technique in which a tissue segment is removed and the breast reshaped through a doughnut-shaped de-epithelialized periareolar area. In this study, we...Purpose: Doughnut mastopexy lumpectomy (DML) is a breast resection technique in which a tissue segment is removed and the breast reshaped through a doughnut-shaped de-epithelialized periareolar area. In this study, we attempted to determine whether the DML technique could be useful for other types of breast surgery, in addition to breast cancer lumpectomy. Methods: This study examined a total of 4 patients who underwent the DML technique and were followed up for at least 1 year postoperatively. One patient underwent phyllodes tumor resection, 1 patient underwent removal of a siliconoma, and 2 patients underwent breast reduction mammaplasty. Results: This method enabled en-bloc removal of a large tissue mass or large foreign body that could not be removed through a short periareolar incision. The surgical method of this study enabled the extent of de-epithelialization to be changed according to the size and location of the mass to be excised;good cosmetic results were also obtained. In addition, the surgical method enabled the facile excision of tumors and foreign materials. Conclusions: The DML technique is a useful surgical method that is applicable to other breast surgeries, in addition to breast cancer surgery.展开更多
Using experimental data from a number of pulsed disc and doughnut solvent extraction columns,a unified correlation for the prediction of dispersed phase holdup that considers the effects of mass transfer is presented....Using experimental data from a number of pulsed disc and doughnut solvent extraction columns,a unified correlation for the prediction of dispersed phase holdup that considers the effects of mass transfer is presented.Pulsed disc and doughnut solvent extraction columns(PDDC) have been used for a range of important applications such as uranium extraction and nuclear fuel recycling.Although the dispersed phase holdup in a PDDC has been presented by some researchers,there is still the need to develop a robust correlation that can predict the experimental dispersed phase holdup over a range of operating conditions including the effects of mass transfer direction.In this study,dispersed phase holdup data from different literature sources for a PDDC were used to refit constants for the correlation presented by Kumar and Hartland [Ind.Eng.Chem.Res.,27(1988),131–138] which did not consider the effect of column geometry.In order to incorporate the characteristic length of the PDDC(i.e.the plate spacing),the unified correlation for holdup proposed by Kumar and Hartland based on data from eight different types of columns [Ind.Eng.Chem.Res.,34(1995) 3925–3940] was refitted to the PDDC data.New constants have been presented for each holdup correlation for a PDDC based on regression analysis using published holdup data from PDDCs that cover a range of operating conditions and physical properties and consider the direction of mass transfer.展开更多
In this study,we propose an effective method for the fabrication of annulus micro-/nanostructures by a femtosecond laser doughnut beam.Compared with the traditional Bessel annulus beam shaping system,this method great...In this study,we propose an effective method for the fabrication of annulus micro-/nanostructures by a femtosecond laser doughnut beam.Compared with the traditional Bessel annulus beam shaping system,this method greatly compresses the light propagation path.It is theoretically and experimentally demonstrated that the obtained axial section of the peak envelope in the processing area is two waists of the isosceles triangle.By moving the relative position of the sample,annulus microstructures with different diameters on copper sheet could be fabricated.In addition,laser induced periodic surface structures with controllable direction are fabricated by this optical system.展开更多
A novel technique of producing azimuthal index 1>1 doughnut beam of good quality by use of multi-liquid crystal cells is presented, it has the advantages of high conversion efficiency and flexibility.
Duplication of alimentary tract(DAT) presenting as an ileoileal intussusception is a very rare clinical entity.Herein,a case of an ileoileal intussusception due to DAT is presented.A 32-year-old woman was hospitalized...Duplication of alimentary tract(DAT) presenting as an ileoileal intussusception is a very rare clinical entity.Herein,a case of an ileoileal intussusception due to DAT is presented.A 32-year-old woman was hospitalized due to diffuse,intermittent abdominal pain,vomiting and constipation for 3 d associated with abdominal distention.Plain abdominal X-ray revealed dilated small bowel.Abdominal computed tomography showed grossly dilated small bowel with "sausage" and "doughnut" signs of small bowel intussusception.She underwent laparotomy,with findings of ileoileal intussusception due to a cystic lesion adjacent to the mesenteric side.Resection of the cystic lesion along with the affected segment of intestine,with an end to end anastomosis was performed.The histopathology was consistent with enteric duplication cyst.This case highlights the DAT,although,an uncommon cause of adult ileoileal intussusception should be considered in the differential diagnosis of intussusception in adults,particularly when the leading point is a cystic lesion.展开更多
基金support of the National Natural Science Foundation of China(21776151 and 21576147)for this investigation。
文摘In this study,a computational fluid dynamics(CFD)method was adopted to calculate axial dispersion coefficients of annular pulsed disc and doughnut columns(APDDCs).Passive tracer was uniformly injected by pulse input at the continuous phase inlet,and its concentration governing equation was solved in liquid–liquidtwo-phase flow fields.The residence time distributions(RTDs)were obtained using the surface monitoring technique.The adopted RTD–CFD method was verified by comparing the axial dispersion coefficient between simulation and experimental results in the literature.However,in pilot-scale APDDCs,the axial dispersion coefficients predicted by the CFD–RTD method were approximately three times larger than experimental results determined by the steady-state concentration profile method.This experimental method was demonstrated to be insensitive to the variation of the axial dispersion coefficient.The CFD–RTD method was more recommended to determine the axial dispersion coefficient.It was found that the axial dispersion coefficient increased with an increase in pulsation intensity,column diameter,and plate spacing,but was little affected by the throughput.
文摘Purpose: Doughnut mastopexy lumpectomy (DML) is a breast resection technique in which a tissue segment is removed and the breast reshaped through a doughnut-shaped de-epithelialized periareolar area. In this study, we attempted to determine whether the DML technique could be useful for other types of breast surgery, in addition to breast cancer lumpectomy. Methods: This study examined a total of 4 patients who underwent the DML technique and were followed up for at least 1 year postoperatively. One patient underwent phyllodes tumor resection, 1 patient underwent removal of a siliconoma, and 2 patients underwent breast reduction mammaplasty. Results: This method enabled en-bloc removal of a large tissue mass or large foreign body that could not be removed through a short periareolar incision. The surgical method of this study enabled the extent of de-epithelialization to be changed according to the size and location of the mass to be excised;good cosmetic results were also obtained. In addition, the surgical method enabled the facile excision of tumors and foreign materials. Conclusions: The DML technique is a useful surgical method that is applicable to other breast surgeries, in addition to breast cancer surgery.
文摘Using experimental data from a number of pulsed disc and doughnut solvent extraction columns,a unified correlation for the prediction of dispersed phase holdup that considers the effects of mass transfer is presented.Pulsed disc and doughnut solvent extraction columns(PDDC) have been used for a range of important applications such as uranium extraction and nuclear fuel recycling.Although the dispersed phase holdup in a PDDC has been presented by some researchers,there is still the need to develop a robust correlation that can predict the experimental dispersed phase holdup over a range of operating conditions including the effects of mass transfer direction.In this study,dispersed phase holdup data from different literature sources for a PDDC were used to refit constants for the correlation presented by Kumar and Hartland [Ind.Eng.Chem.Res.,27(1988),131–138] which did not consider the effect of column geometry.In order to incorporate the characteristic length of the PDDC(i.e.the plate spacing),the unified correlation for holdup proposed by Kumar and Hartland based on data from eight different types of columns [Ind.Eng.Chem.Res.,34(1995) 3925–3940] was refitted to the PDDC data.New constants have been presented for each holdup correlation for a PDDC based on regression analysis using published holdup data from PDDCs that cover a range of operating conditions and physical properties and consider the direction of mass transfer.
基金This work was supported by the National Natural Science Foundation of China(No.51975595)the Joint Funds of Ministry of Education of China(No.6141A02022130).
文摘In this study,we propose an effective method for the fabrication of annulus micro-/nanostructures by a femtosecond laser doughnut beam.Compared with the traditional Bessel annulus beam shaping system,this method greatly compresses the light propagation path.It is theoretically and experimentally demonstrated that the obtained axial section of the peak envelope in the processing area is two waists of the isosceles triangle.By moving the relative position of the sample,annulus microstructures with different diameters on copper sheet could be fabricated.In addition,laser induced periodic surface structures with controllable direction are fabricated by this optical system.
文摘A novel technique of producing azimuthal index 1>1 doughnut beam of good quality by use of multi-liquid crystal cells is presented, it has the advantages of high conversion efficiency and flexibility.
文摘Duplication of alimentary tract(DAT) presenting as an ileoileal intussusception is a very rare clinical entity.Herein,a case of an ileoileal intussusception due to DAT is presented.A 32-year-old woman was hospitalized due to diffuse,intermittent abdominal pain,vomiting and constipation for 3 d associated with abdominal distention.Plain abdominal X-ray revealed dilated small bowel.Abdominal computed tomography showed grossly dilated small bowel with "sausage" and "doughnut" signs of small bowel intussusception.She underwent laparotomy,with findings of ileoileal intussusception due to a cystic lesion adjacent to the mesenteric side.Resection of the cystic lesion along with the affected segment of intestine,with an end to end anastomosis was performed.The histopathology was consistent with enteric duplication cyst.This case highlights the DAT,although,an uncommon cause of adult ileoileal intussusception should be considered in the differential diagnosis of intussusception in adults,particularly when the leading point is a cystic lesion.
