• Journal of Environmental Science International
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• v.19 no.11
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• pp.1423-1436
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• 2010

The effects of meteorological and reclaiming conditions on the reduction of suspended particles are investigated using a computational fluid dynamics (CFD) model with the k-$\varepsilon$ turbulence closure scheme based on the renormalization group (RNG) theory. Twelve numerical experiments with different meteorological and reclaiming conditions are performed. For identifying the meteorological characteristics of the target area and providing the inflow conditions of the CFD model, the observed data from the automatic weather station (AWS) near the target area is analyzed. Complicated flow patterns such as flow distortion, horse-shoe vortex, recirculation zone, and channeling flow appeared due to the topography and buildings in the domain. Specially, the flow characteristics around the reclamation area are affected by the reclaiming height, reclaiming size and windbreak height. Reclaiming height affected the wind speed above the reclaiming area. Windbreak induces more complicated flow patterns around the reclaiming area as well as within the reclaiming area. In front of the windbreak, flow is distorted as it impinges on the windbreak. As a result, upward flow is generated there. Behind the windbreak, a secondary circulation, so called, a recirculation zone is generated and flow is reattached at the end of the recirculation zone (reattachment point). At the lower part of the recirculation zone, there is a reverse flow toward the windbreak. Flow passing to the reattachment point starts to be recovered. Total amounts of suspended particles are calculated using the frictional and threshold frictional velocities, erosion potential function, and the number of surface disturbance. In the case of a 10 m-reclaiming and northerly wind, the amount of suspended particles is largest. In the presence of 5 m windbreak, the friction velocity above the reclaiming area is largely reduced. As a result, the total amount of the suspended particles largely decreases, compared to the case with the same reclaiming and meteorological conditions except for the windbreak The calculated suspended particle amounts are used as the emission rate of the dispersion model simulations and the dispersion characteristics of the suspended particles are analyzed.

• Journal of the Korean Orthopaedic Association
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• v.54 no.2
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• pp.110-119
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• 2019

Proximal humerus fracture can be defined as a fracture that occurs in the surgical neck or proximal part of the humerus. Despite the appropriate treatment, however, various complications and sequelae can occur, and the treatment is quite difficult often requiring surgical treatment, such as a shoulder replacement. The classification of sequelae after a proximal humerus fracture is most commonly used by Boileau and can be divided into two categories and four types. Category I is an intracapsular impacted fracture that is not accompanied by important distortions between the tuberosities and humeral head. An anatomic prosthesis can be used without greater tuberosity osteotomy. In category I, there are type 1 with cephalic collapse or necrosis with minimal tuberosity malunion and type 2 related to locked dislocation or fracture-dislocation. Category II is an extracapsular dis-impacted fracture with gross distortion between the tuberosities and the humeral head. To perform an anatomic prosthesis, a tuberosity osteotomy should be performed. In category II, there are type 3 with nonunion of the surgical neck and type 4 with severe tuberosity malunion. In type 1, non-constrained arthroplasty (NCA) without a tuberosity osteotomy should be considered as a treatment. On the other hand, reverse shoulder arthroplasty (RSA) should be considered if types 1C or 1D accompanied by valgus or varus deformity or severe fatty degeneration of the rotator cuff. In general, the results are satisfactory when NCA is performed in type 2 sequelae. On the other hand, RSA can be considered as an option when there is no bony defect of the glenoid and a defect of the rotator cuff is accompanied. In type 3, it would be effective to perform internal fixation with a bone wedge graft rather than shoulder replacement arthroplasty. Recent reports on the results of RSA are also increasing. On the other hand, recent reports suggest that good results are obtained with RSA in type 3. In type 4, RSA should be considered as a first option.