Sharif Digital Repository

Purpose: The purpose of this paper is to examine cigarette consumption behavior of younger cohorts in the urban and rural areas of Iran. The authors use Iran’s annual Household Income and Expenditures Surveys (HIES) database over 2007–2013 for the statistical analysis. In order to control for a large number of households with zero expenditure on cigarette consumption, the authors have used the double-hurdle modeling approach for counting the outcomes of interest. The authors have also limited the sample to cases in which the head of household is between the ages of 21 and 45 and all children are younger than 18. Design/methodology/approach: In this study, the authors have conducted a... 

A new mathematical method is proposed to model the transport of polydisperse submicron aerosol particles in a heterogeneous porous media, and as an example, it is applied to study the transport of mainstream smoke aerosol particles in the cigarette tobacco column. The tobacco column is composed of randomly distributed pores and the aerosol particle transport is modeled utilizing a pore sub-model and taking into account aerosol particle coagulation and deposition. Copyright © 2009 Begell House, Inc  

Superhydrophobic materials have attracted many attentions in recent years while their application in sample preparation remained almost intact. In this project, a rough surface of melamine formaldehyde foam was silanized by chemical deposition of trichloromethylsilane to form a highly porous and superhydrophobic material, presumably a suitable medium for extracting non–polar compounds such as benzene and its methyl derivatives. The prepared sorbent was packed in a needle for the headspace needle–trap microextraction of benzene, toluene, ethylbenzene and xylenes (BTEX). Major parameters associated with the extraction/desorption processes were considered for optimization. Under the optimized... 

Background Oesophageal cancer is a common and often fatal cancer that has two main histological subtypes: oesophageal squamous cell carcinoma and oesophageal adenocarcinoma. Updated statistics on the incidence and mortality of oesophageal cancer, and on the disability-adjusted life-years (DALYs) caused by the disease, can assist policy makers in allocating resources for prevention, treatment, and care of oesophageal cancer. We report the latest estimates of these statistics for 195 countries and territories between 1990 and 2017, by age, sex, and Socio-demographic Index (SDI), using data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD). Methods We used data...