This Standard specifies maximum permissible ambient noise levels (MPANLs) allowed in an audiometric test room that produce negligible masking ( 2 dB) of test signals presented at reference equivalent threshold levels specified in ANSI S3.6-1996 American National Standard Specification of Audiometers. The MPANLs are specified from 125 to 8000 Hz in octave and one-third octave band intervals for ...

Higher layer protocols in wireless networks need to dynamically adapt to observed network response. A common approach is for each protocol to employ an end-to-end monitoring and measuring mechanism and estimate quantities of interest, usually related to delay, latency or bandwidth. A less conventional approach is to employ network layer feedback mechanisms in place or in aid of end-to-end effor...

long-term exposure to high concentrations of fluoride is associated with several adverse effects on human including dental and skeletal fluorosis. we studied all the groundwater wells located in rural areas of khaf city, razavi province, northeastern iran between 2009 and 2010. fluoride concentration of water samples was measured by spadns method. we found that in rural areas the fluoride conce...

Introduction: In recent years, attraction toward drinking bottled mineral water has increased. Therefore, chemical composition and safety of these waters considering trace elements and heavy metals should confirm the national or international standard limits. The aim of this study was to evaluate and comparison of the mineral and heavy metal composition of bottled waters in Bandar Abbas with Ir...

Background: Anecdotal information has suggested that sodium benzoate is used with more than permissible doses during production steps of food products especially pickles and pickled cucumbers in food producing factories in Markazi province and other food producing factories . The present study was done to evaluate factual concentration of sodium benzoate in these products. Methods: In this ...