The shell liner type, rotation speed, and ball filling percent are the key factors influencing the charge behavior inside the SAG mills, and consequently, their performance. In this work, the milling operation of industrial SAG mills is investigated using the Discrete Element Method (DEM). First, an industrial SAG mill with dimensions of 9.50 m × 4.42 m that has a Smooth-type liner is sim...

Liner design has become an increasingly more important tool for the AG/SAG mill performance optimization. The Sarcheshmeh copper complex concentration plant uses a SAG mill lined with 48 rows of Hi-Low type liners. Because of breakage of Low type liners and cold welding, the liner replacement task of Low with new Hi type liners has become very difficult and time-consuming. With the objective of...

Dislocations of total hip prostheses cause pain and patient dissatisfaction. Recurrent dislocations are difficult to treat mainly when the acetabular metal shell is well-fixed. The purpose of this article was to describe the surgical technique used for the treatment of a bilateral recurrent posterior dislocation after a cementless total hip prosthesis, caused by excessive inclination of acetabu...

Fifty-eight patients received an Osteonics constrained acetabular implant for recurrent instability (46), girdlestone reimplant (8), correction of leg lengthening (3), and periprosthetic fracture (1). The constrained liner was inserted into a cementless shell (49), cemented into a pre-existing cementless shell (6), cemented into a cage (2), and cemented directly into the acetabular bone (1). Ei...

32 patients received a Trilogy- or Trilogy-Longevity-constrained acetabular liner for recurrent dislocations after total hip replacement. The constrained liner was inserted into a well-fixed Trilogy acetabular shell with snap fit. At 1.8-year followup (range 3-63 months), 4 patients had suffered further dislocation(s) (12%), and one patient had revision surgery for a loosened acetabular shell. ...

Motorcycles are considered a cost-effective and major means of transportation, particularly in the developing countries. However, motorcyclists are at higher risk of head and brain injuries in road crashes, which is the primarily cause of most of the fatalities occurred. Wearing a protective helmet is an efficient way for the safety of the motorcyclist, since it reduces the severity of head inj...

A 75-year-old woman who suffered a left femoral neck fracture underwent a left total hip arthroplasty using a Stryker Trident (Kalamazoo, MI) hemispherical acetabular shell and Modular Dual Mobility (MDM) metal liner. Post-operative radiographs demonstrated canted seating of the liner. The patient was taken immediately back to the operating room where the acetabular liner appeared well seated s...

The dual mobility hip implant has been introduced recently and increasingly used in total hip replacement to maintain the stability and reduce the risk of post-surgery dislocation. However, the kinematics and contact mechanisms of dual mobility hip implants have not been investigated in detail in the literature. Therefore, finite element method was adopted in this study to investigate dynamics ...

Elastic liners are used for in situ repair and retrofitting of pipes as a cost effective alternative to the replacement of damaged parts and sections. In this paper, we studied the role of an elastic liner on the buckling behavior of a cracked cylindrical shell using finite element method. A special meshing scheme that could mimic the stress singularity at the crack tip was employed to model th...

Polyethylene liners of modular acetabular components wear sometimes need to be replaced, despite the metal shell being well fixed. Replacing the liner is a relatively simple procedure, but very little is known of the outcome of revision. We prospectively followed up 1126 Harris-Galante I metal-backed, uncemented components for between nine and 19 years. We found 38 (3.4%) liners of 1126 acetabu...