The high Cr, Ni base superalloy IN738LC has been directionally solidified on both laboratory and industrial scales using Bridgman and liquid metal cooling (LMC ) methods respectively. In the Bridgman experiments, cylindrical rods were grown using a graphite chill with temperature gradient G=5•0 K mm−1 and a water cooled copper chill with G=8•5 K mm−1, and a wide range of withdrawal rates of R=60, 120, 240, 600, and 1200 mm h−1. In the LMC rigs, several turbine blades were grown using a wide range of withdrawal rates of R=120, 225, 330, 420, and 630 mm h−1. Grain and dendritic structures in both cylindrical and turbine blade specimens were evaluated in longitudinal and transverse directions. Dendritic segregation of rods was determined with SEM as a function of processing parameters. Some specimens were given a two stage heat treatment followed by tension tests at 25 and 650?C and creep tests at 152 MPa and 982?C, 340 MPa and 850?C, and 586 MPa and 760?C. It was shown that at R=600 mm h−1 with water cooled copper chill, directionally solidified rods with a well orientated dendritic structure and better segregation pattern gives higher tensile properties at 25?C and creep properties at 340 MPa and 850?C. Tension and creep tests of turbine blades showed that although the yield and tensile strength of directionally solidified specimens are in the range of conventionally cast ones, the creep properties of the blades have been significantly improved using the LMC process.MST/4210

No abstract

No abstract

No abstract

Brucellosis a world-wide disease having diverse clinical manifestations, affecting hundreds of individuals annually. Its prevalence is different in different countries and even in different regions of the same country. It can be diagnosed by different methods each one having different sensitivity and specificity and even it depends on the laboratory facilities of the concern area. Although it is usually screened by Slide Agglutination Test (SAT) and blood culture techniques, but these may produce false positive results and having extended time for test results respectively. A total of 82 patients were selected over a one-year period between March 2014 and April 2015. All patients' sera were processed for culture using BACTEC 9240 system followed by testing by ELISA. Among 82 suspected patients, only 30 (%) were positive for culture and remaining 52 (%) were negative.While ELISA IgM and IgG were 15% and 22% respectively among culture positive samples. ROC curve showed the behavior of the sensitivity and specificity of ELISA IgG and IgM by using different cut-off points. In patients with brucellosis, the mean of serum IgG was greater than IgM, significantly (P<0.001). ELISA IgG test was more reliable than ELISA IgM test in diagnosis of brucellosis in Iran.