We have reviewed quality control testing of dose calibrators and have analyzed the potential for error. The uncertainty in half-lives of reference sources can lead to inaccurate assessment of the accuracy and constancy in dose calibrator performance. Molybdenum-99 contamination of '"Tc used as a reference source can appear as a nonlinear response of the dose calibrator. The useful life of a ref...

mycoplasma and ureaplasma species are the most serious contaminants of cell cultures and this remains one of the major problem encountered in biological research using cell cultures. the aim of this study was to investigate the rate of mycoplasma and a total of 100 different cell culture specimens including, r228, hela, vero, mdck, l20, rd and hep2 were collected. then the specimens were invest...

objectives the aim of this study was to assess soils of khorramabad metropolis in order to establish the concentration of lead and develop a contamination factor map. materials and methods soil samples were collected from 25 different urban parks in khorramabad, iran. the mean pb contents in the urban topsoil samples were compared with mean concentrations for other cities around the world. a sp...

Abstract This paper presents evidence from both corpora and agent-based simulation for the effect of lectal contamination. By doing so, it shows how can be used as a complementary technique to corpus research in study language variation. Lectal contamination is an whereby words that are typical variety more often appear morphosyntactic variant same variety, even among use different variety. loo...