maximizing economic earnings is the most common goal in cut-off grade optimization of open-pit mining operations. when this is the case, the price of the product has a critical effect on optimum value of cut-off grade. this paper investigates the relationship between optimum cut-off grade and price to maximize total cash flow and net percent value (npv) of operation. in order to visualize this ...

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...

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...

having observed the costly failures of different cutoff walls, that had been constructed according to the mix design specified by reputable consultants in iran, a research programme was conducted to study the effects of constituent materials on the properties of plastic concrete. the main properties, such as compressive strength, biaxial and triaxial strains, permeability, and modulus of elasti...

We answer the question: If a vacuum sector Hamiltonian is regularized by an energy cutoff, how one-kink regularized? find that it not indeed normal modes of all energies are present in kink Hamiltonian, but rather decomposition field into mode operators yields coefficients which lie on constrained surface forces them to become small for above cutoff. This explains old observation cutoff leads i...

chitosan/polyethersulfone (cs/pes) composite membrane was prepared from casting chitosan solution on polyethersulfone substrate membrane. the substrate membrane was prepared by phase inversion technique using polyethersulfone (pes) and dimethylacetamide (dmac) as solvent with and without the addition of polyvinylpyrrolidone (pvp) as pore-forming agent. the effects of the composition of the c...

Background: Assessment of AMH cut-off levels in serum and in follicle fluid (FF) for patients with (group 2, n=34) and without (group1, n= 96) endocrinological risk factors, such as ovarian hyperstimulation syndrome (OHSS) and polycystic ovary syndrome (PCOS), is clinically useful in optimising the treatment protocol. Materials and Methods: AMH was analysed in serum and FF of 130 infertile pati...

background: risk of malignancy index (rmi) is the best method for discriminating benign and malignant pelvic masses. the aim of this study was to determine the rmi for preoperative evaluation of pelvic mass. methods: this study was performed on 182 women with adenexal mass referred to yahyahnejiad hospital of babol university of medical sciences in iran from 2007 to 2009.the sensitivity, specif...