Effects of Natural and Forced Entrainment on PM Emissions from Fire Whirls.

The influence of different air entrainment conditions on the emissions of particulate matter from fire whirls was investigated by igniting a diesel fuel pool, 0.7 m in diameter, within a four-walled enclosure. Four different natural entrainment conditions resulted when gap sizes in the walls were varied between 0.35 and 0.65 m. In addition, three forced-entrainment conditions were created by holding the gap width constant and varying the air-entrainment velocity using fans positioned at each of the four gaps. The concentration of particulates was measured for these seven conditions, and one pool fire condition for comparison. For fire whirls under natural entrainment, the emission factor of total particulate matter, EFPM, was lower than that for pool fires, and decreased with increasing gap size. Fire whirls under mild levels of forced entrainment showed the lowest values of EFPM, but as the level of forced entrainment was increased, EFPM increased steadily to a value higher than that of pool fires. The reduction in EFPM is attributed to a combination of leaner stoichiometry and the interaction between the entrainment and the instantaneous burning rate. Thus, for a given pool diameter, an optimum value of entrainment velocity exists where the EFPM is lowest. Considerations for utilizing whirling flames to reduce airborne particulate emissions from in situ burning are discussed.

Development of a field-friendly automated dietary assessment tool and nutrient database for India.

Studies of diet and disease risk in India and among other Asian-Indian populations are hindered by the need for a comprehensive dietary assessment tool to capture data on the wide variety of food and nutrient intakes across different regions and ethnic groups. The nutritional component of the India Health Study, a multicentre pilot cohort study, included 3908 men and women, aged 35-69 years, residing in three regions of India (New Delhi in the north, Mumbai in the west and Trivandrum in the south). We developed a computer-based, interviewer-administered dietary assessment software known as the 'NINA-DISH (New Interactive Nutrition Assistant - Diet in India Study of Health)', which consisted of four sections: (1) a diet history questionnaire with defined questions on frequency and portion size; (2) an open-ended section for each mealtime; (3) a food-preparer questionnaire; (4) a 24 h dietary recall. Using the preferred meal-based approach, frequency of intake and portion size were recorded and linked to a nutrient database that we developed and modified from a set of existing international databases containing data on Indian foods and recipes. The NINA-DISH software was designed to be easily adaptable and was well accepted by the interviewers and participants in the field. A predominant three-meal eating pattern emerged; however, patterns in the number of foods reported and the primary contributors to macro- and micronutrient intakes differed by region and demographic factors. The newly developed NINA-DISH software provides a much-needed tool for measuring diet and nutrient profiles across the diverse populations of India with the potential for application in other South Asian populations living throughout the world.