Retention characteristics of UF membranes are de— lineated through comparison of the combined viscous flow and frictional model with the Ferry—Faxen equation. The molecular weight cut—off concept is discussed using calculations of how sharp cut-off curves one can expect of UF membranes with uniform pore sizes and how heteroporosity will affect such curves. Experimental retention—flux curves for...

in the open-pit mining, one of the first decisions that must be made in production planning stage, after completing the design of final pit limits, is determining of the processing plant cut-off grade. since this grade has an essential effect on operations, choosing the optimum cut-off grade is of considerable importance. different goals may be used for determining optimum cut-off grade. one of...

This work investigates the structural formation and analyses of titania membranes (TM) prepared using different vacuum exposure times for molecular weight (MW) cut-off performance and oil/water separation. Titania membranes were synthesized via a sol-gel method and coated on macroporous alumina tubes followed by exposure to a vacuum between 30 and 1200 s and then calcined at 400 °C. X-ray diffr...

background: to determine a cut-off point of tpsa and psad to prevent unnecessary invasive cancer-diagnosing tests in the community. methods: this study was performed on 688 consecutive patients referred to our center due to prostatism, suspicious lesions on digital rectal examination and/or elevated serum psa levels. all patients underwent transrectal ultrasound guided biopsies and obtained psa...