Environmental Health Perspectives • volume 119 | number 7 | July 2011 A 283 acquiesced to that point in a reply to the first of several letters to the editor by Brondum (2007) on the same topic. However, Braun et al. (2007) noted that including such information is not always possible when, for example, the use of National Health and Nutrition Examination Survey (NHANES) data or other constraint...

Analysts agree about the need for developing both new and cleaner energy resources. At the same time, some argue that energy efficiency can provide only a minimal role in meeting future energy needs. Hence, energy supply is encouraged while energy efficiency is supported only minimally. Analysts Douglas Lightfoot and Christopher Green suggest in a series of papers, for example, that there are p...

Increasing energy end-use efficiency—technologically providing more desired service per unit of delivered energy consumed—is generally the largest, least expensive, most benign, most quickly deployable, least visible, least understood, and most neglected way to provide energy services. The 46% drop in U.S. energy intensity (primary energy consumption per dollar of real GDP) during 1975–2005 rep...

p. 396, col. 2, full para. 2 ("Perhaps..."): The vehicle efficiency stated is from a simulation of on-road performance, obtained by multiplying each vector in the standard EPA test cycles by 1.3. The equivalent EPA adjusted efficiency (the kind used for official efficiency ratings and shown on the window stickers of market vehicles) is 2.06 L-equivalent per 100 km, 48.5 km/L-equivalent, or 114 ...

www.sciencemag.org SCIENCE VOL 325 14 AUGUST 2009 785 COVER Pulsars in our Galaxy newly discovered by the Fermi Gamma-ray Space Telescope, launched in June 2008. The objects emit broad gamma-ray beams that have enabled Fermi to locate a never-before-seen population. Fermi has also seen pulsars with millisecond periods and has detected at least one globular cluster (center left). See the Researc...

OS resource management policies traditionally employ buffering to “smooth out” fluctuations in resource demand. By minimizing the length of idle periods and the level of contention during non-idle periods, such smoothing tends to maximize overall throughput and minimize the latency of individual requests. For certain important devices, however (disks, network interfaces, or even computational e...

externality An economically significant effect of an activity, the consequences of which are borne (at least in part) by parties other than the party who engages in the activity, and which are not accounted for through trade. diffusion The gradual adoption of new process or product innovations by firms and individuals. innovation The initial market introduction or commercialization of new proce...

Low efficiencies and costly electrode materials have limited harvesting of thermal energy as electrical energy using thermo-electrochemical cells (or "thermocells"). We demonstrate thermocells, in practical configurations (from coin cells to cells that can be wrapped around exhaust pipes), that harvest low-grade thermal energy using relatively inexpensive carbon multiwalled nanotube (MWNT) elec...

in this article, non radial method of dynamic dea with the parallel network structure is presented and is used for calculation of relative efficiency measures when inputs and outputs do not change equally. in this model, dmu divisions under evaluation have been put together in parallel. but its dynamic structure is assumed in series. since in real applications there are undesirable inputs and o...