Global emission of black carbon from motor vehicles from 1960 to 2006.

Black carbon (BC) is a key short-lived climate change forcer. Motor vehicles are important sources of BC in the environment. BC emission factors (EF(BC)), defined as BC emitted per mass of fuel consumed, are critical in the development of BC emission inventories for motor vehicles. However, measured EF(BC) for motor vehicles vary in orders of magnitude, which is one of the major sources of uncertainty in the estimation of emissions. In this study, the main factors affecting EF(BC) for motor vehicles were investigated based on 385 measured EF(BC) collected from the literature. It was found that EF(BC) for motor vehicles of a given year in a particular country can be predicted using gross domestic product per capita (GDP(c)), temperature, and the year a country's GDP(c) reached 3000 USD (Y(3000)). GDP(c) represents technical progress in terms of emission control, while Y(3000) suggest the technical transfer from developed to developing countries. For global BC emission calculations, 87 and 64% of the variation can be eliminated for diesel and gasoline vehicles by using this model. In addition to a reduction in uncertainty, the model can be used to develop a global on-road vehicle BC emission inventory with spatial and temporal resolution.

Weather, geography, and vehicle-related hyperthermia in children.

Vehicle-related hyperthermia is an unfortunate tragedy that leads to the accidental deaths of children each year. This research utilizes the most extensive dataset of child vehicle-related hyperthermia deaths in the United States, including 414 deaths between 1998 and 2008. Deaths follow a seasonal pattern, with a peak in July and no deaths in December or January. Also, deaths occurred over a wide range of temperature and radiation levels and across virtually all regions, although most of them took place across the southern United States. In particular, the Phoenix, Houston, Dallas, and Las Vegas metropolitan areas had the greatest number of deaths. We utilize our vehicle hyperthermia index (vhi) to compare expected deaths versus actual deaths in a metropolitan area, based on the number of children in the area who are under the age of five and on the frequency of hot days in the area. The vhi indicates that the Memphis, West Palm Beach-Boca Raton, and Las Vegas metropolitan areas are the most dangerous places for vehicle-related hyperthermia. We conclude by discussing several recommendations with public health policy implications.

A short history of powered wheelchairs.

This article recounts some early findings on a history of powered wheelchairs in the 20th century from an analysis of archival materials, oral accounts, and secondary sources. The primary goal of this article is not to provide the definitive history of powered wheelchairs, but rather to further our understanding of wheelchair innovation through a historical analysis. The paper sheds light on some of the richness and complexities involved in powered wheelchair innovation, highlights the nonlinearity of that process, and explores the roles of and the relationships between social and technological change. Although it is evident that powered mobility has revolutionized the life experiences of many disabled people, enabling independence, social interaction, and even the facilitation of socio-psychological development, few have charted the social and technological topography that brought this revolutionary change about. In partially mapping the history of powered wheelchairs, this paper draws attention to the idea that wheelchairs are not simply technical devices, but also social and political machines entwined with socio-political conditions and expectations.

Adapting military field water supplies to the asymmetric battlefield.

Army transformation to a brigade-centric force has created a distributed battlefield, challenging the surveillance and logistical supply of field water. The daily requirement of up to 15 gal of potable water per person per day from bulk water supplies has been achievable for many years using currently fielded ROWPUs. However, the need to reduce the transport of water and move towards a sustainable force has created a gap in materiel capable of producing safe water at the individual and unit level. While materiel development is slow, the PM community, tasked with doctrine development and battlefield oversight of field water, is beginning to address the requirements of field water on the changed battlefield. In addition to materiel gaps, the transformed battlefield has created a lack of trained personnel for water production and oversight. Without trained operators and PM oversight, to what level of health risk are consumers of this water exposing themselves? Currently PM is unable to answer this question but is working diligently with the RDT&E community to develop materiel solutions, and with the medical community to provide interim guidance to reduce the potential health risks to using such equipment.