Self-consistent Coulomb effects and charge distribution of quantum dot arrays

This paper considers the self-consistent Coulomb interaction within arrays of self-assembled InAs quantum dots (QDs) which are embedded in a pn structure. Strong emphasis is being put on the statistical occupation of the electronic QD states which has to be solved self-consistently with the actual three-dimensional potential distribution. A model which is based on a Green's function formalism including screening effects is used to calculate the interaction of QD carriers within an array of QDs, where screening due to the inhomogeneous bulk charge distribution is taken into acount. We apply our model to simulate capacitance-voltage (CV) characteristics of a pn structure with embedded QDs. Different size distributions of QDs and ensembles of spatially perodic and randomly distributed arrays of QDs are investigated.Comment: submitted to pr

Prevalence and costs of hospitalizations for poisoning and accidental intoxication in Brazilian elderly

A cross-sectional study of secondary data/information obtained from the Hospital Information System (HIS) spanning the years 2008 - 2009 was performed. The distribution of the main hospital admissions by gender, age, color/race, region and federal unit of residence, average expenditure and average length of hospital stay, year of hospitalization and mortality rates (MR) were studied. The data collected were tabulated by TabNet and keyed into Microsoft Excel 2007. It was verified that elderly males (54.3%), from 60 to 69 years old (50.6%), nonwhites (36.3%) and residents of Southeast and North regions of the country had the highest rates of hospitalization. Seniors were hospitalized for an average of 4.8 days, and the major causes were exposure to alcohol (43.7%) and to drugs (33.9%). Expenses related to hospital admissions were, on average, R$ 529,817.70. The highest mortality rates were recorded among females (MR = 4.34), in elderly, 80 years or older (MR = 10.16) and Caucasians (MR = 3.95), where pharmacological substances with action on the Autonomic Nervous System were the leading cause of death. There are demographic differences in morbi-mortality of these elderly since, although men and younger elderly were the main victims, women and elderly of advanced age have greater mortality. The leading causes of hospitalization were alcohol and drugs