Effect of Thermal Convection on Density Segregation in Binary Granular Gases with Dissipative Lateral Walls

Molecular dynamics simulations are employed to investigate the effect of thermal convection induced only by dissipative lateral walls on density segregation of the strongly driven binary granular gases under low gravity conditions. It is found that the thermal convection due to dissipative lateral walls has significant influence on the segregation intensity of the system. The dominant factor in determining the degree of segregation achieved by the system is found to be the relative convection rate between differing species. Moreover, a qualitative explanation is proposed for the relationship between the thermal convection due to dissipative lateral walls and the observed segregation intensity profiles.

Outcome of buttress plate-nail construct used for reconstruction of broken lateral wall in intertrochanteric fractures

Purpose:Intramedullary implants are well accepted fixation of all types of intertrochanteric(IT)frac-tures,both stable and unstable types.Intramedullary nails have an ability to effectively support the posteromedial part,but fail to buttress the broken lateral wall requiring lateral augmentation.The aim of this study was to evaluate the outcome of proximal femoral nail augmented with trochanteric buttress plate for broken lateral wall with IT fractures,which was fixed to the femur through hip screw and anti-rotation screw nail.Methods:Of 30 patients,20 had Jensen-Evan typeⅢand 10 had type V fractures.Patients with IT fracture of broken lateral wall and aged more than 18 years,in whom satisfactory reduction was achieved by closed methods,were included in the study.Patients with pathologic or open fractures,polytrauma,prior hip surgery,non-ambulatory prior to surgery,and those who refused to participate were excluded.The operative time,blood loss,radiation exposure,quality of reduction,functional outcome,and union time were evaluated.All data were coded and recorded in Microsoft Excel spread sheet program.SPSS 20.0 was used for data analysis and normality of the continuous data was checked using Kolmogorv Smirnov test.Results:The mean age of patients in the study was 60.3 years.The mean duration of surgery(min),mean intra-operative blood loss(mL)and mean number of exposures were 91.86±12.8(range 70-122),144.8±3.6(range 116-208),and 56.6(range 38-112),respectively.The mean union time was 11.6 weeks and the mean Harris hip score was 94.1.Conclusion:Lateral trochanteric wall in IT fractures is significantly important,and needs to be recon-structed adequately.Nail-plate construct of trochanteric buttress plate fixed with hip screw and anti-rotation screw of proximal femoral nail can be successfully used to augment,fix or buttress the lateral trochanteric wall giving excellent to good results of early union and reduction.

Advances in the Restoration and Fixation of Lateral Femoral Wall Fracture

Hip fractures,especially intertrochanteric fractures,are more common with aging.After decades of progress,it is a general consensus to carry out internal fixation for this group of patients.However,the recent focus is on unstable intertrochanteric fractures to ensure better prognosis and prevent internal fixation failure.The lateral femoral wall,as a novel concept,is often disregarded.Many scholars have recognized that the lateral wall of the proximal femoral plays a crucial role in the stability of internal fixation for intertrochanteric fractures.In this paper,the historical evolution,definition,clinical significance,injury classification,choice of internal fixation,and possible prognosis of lateral femoral wall fracture are reviewed in order to provide clinicians strong evidence of treatment strategies.

Interaction analysis of back-to-back mechanically stabilized earth walls

Back-to-back mechanically stabilized earth walls （BBMSEWs） are encountered in bridge approaches, ramp ways, rockfall protection systems, earth dams, levees and noise barriers. However, available design guidelines for BBMSEWs are limited and not applicable to numerical modeling when back-to-back walls interact with each other. The objective of this paper is to investigate, using PLAXIS code, the effects of the reduction in the distance between BBMSEW, the reinforcement length, the quality of backfill material and the connection of reinforcements in the middle, when the back-to-back walls are close. The results indicate that each of the BBMSEWs behaves independently if the width of the embankment between mechanically stabilized earth walls is greater than that of the active zone. This is in good agreement with the result of FHWA design guideline. However, the results show that the FHWA design guideline underestimates the lateral earth pressure when back-to-back walls interact with each other. Moreover, for closer BBMSEWs, FHWA design guideline strongly overestimates the maximum tensile force in the reinforcement. The investigation of the quality of backfill material shows that the minor increase in embankment cohesion can lead to significant reductions in both the lateral earth pressure and the maximum tensile force in geosynthetic. When the distance between the two earth walls is close to zero, the connection of reinforcement between back-to-back walls significantly improves the factor of safety.