sound power is considered as an excellent measure for evaluating the efficiency of noise controls as well as for comparing noise sources in workrooms. this parameter can be determined by sound pressure or intensity based methods in real conditions of workrooms. this paper aims empirically to compare these in situ methods in relation to a typical industrial machine located in workroom in terms o...

in this work, a thermoplastic polyurethane elastomer (tpue) model based on polytetramethylene glycol, toluene diisocyanate and 1,4-butanediol was selected and synthesized. according to this model two types of polyurethane nanocomposites were prepared by in situ polymerization and melt intercalation procedures. the organo-modified nanoclay was used in nanocomposites samples in 0.4 weight percent...

bis(2-r-ind)zrcl2 (r: h or phenyl) was supported on different types of silica by in situ impregnation method and used for ethylene polymerization. in this method, the step of catalyst loading on support was eliminated and common alkyl aluminum (triisobutylaluminum, tiba) cocatalyst was used instead of expensive methyl aluminiumoxane (mao) cocatalyst in the polymerization. the effect of surface ...

background: flat urothelial lesions comprise a spectrum of morphologic changes ranging from reactive atypia to carcinoma in situ (cis). urothelial dysplasia and cis are associated with the recurrence and progression of urothelial carcinoma. distinguishing cis and dysplasia from reactive atypia based on histolopathogical features alone is often difficult. using different immunohistochemical mark...

background: various frequencies of sperm aneuploidy are reported in sperms of subfertile patients compared to normal individuals. moreover, sperm dna damage is shown to be associated with male infertility. in this study, the rate of dna damage and frequencies of aneuploidy in sperms of subfertile patients was investigated. methods: semen samples were obtained from healthy normal and subfertile ...

two facile and low cost routes were used for the synthesis of if-ws2 nanoparticles. in this paper, preparation of if-ws2 nanoparticles with two different methods was investigated. in the first method, wo3 nanoparticles were reacted with h2s gas in n2/h2 reducing atmosphere at 900 oc. the as-synthesized if-ws2 nanoparticles are spherical shape with an average size of about 70 nm.  in the second ...

in this research, using pyrolysis of phenolic resin in the presence of silicon particles, the sic ceramic composite is formed. the samples were prepared by introducing 30, 35, 40, 45 and 50 wt% of si particles to the phenolic resin. the samples were cured at 180°c then carbonized at 1100°c. the final carbonized c/si composites are hot-pressed at 1500°c in inert atmosphere, which is more than th...

a new method was used to prepare abs/pa6 blends by in situ polymerization and compatibilization method. in this process, ε-caprolactam monomer was polymerized in presence of abs via activated anionic polymerization to produce pa6. the main ingredients of the reaction mixture included: monomer ()ε-caprolactam), catalyst na-caprolactamate), microactivator hdi)( and macro-activator sma)(. then, in...