We explored repurposing discarded materials to construct simple, field expedient, solar heating devices capable of heating drinking water to water pasteurization temperatures. Results of different test configurations quickly constructed from junk material indicate important design parameters to include maximizing exposed container surface area and using transparent glass and dark absorbent mate...

Boiling is a very efficient way to transfer heat from a heater to the liquid carrier. We discuss the boiling crisis, a transition between two regimes of boiling: nucleate and film boiling. The boiling crisis results in a sharp decrease in the heat transfer rate, which can cause a major accident in industrial heat exchangers. In this communication, we present a physical model of the boiling cris...

Nanosized gas sensor elements are potentially faster, require lower power, come with a lower limit of detection, operate at lower temperatures, obviate the need for expensive catalysts, are more heat shock resistant and might even come at a lower cost than their macro-counterparts. In the last two decades, there have been important developments in two key areas that might make this promise a re...

From January 1997 to April 1999, we determined attack rates for cases of invasive group A streptococcal (GAS) disease in household contacts of index patients using data from Active Bacterial Core Surveillance sites. Of 680 eligible index-patient households, 525 (77.2%) were enrolled in surveillance. Of 1,514 household contacts surveyed, 127 (8.4%) sought medical care, 24 (1.6%) required hospita...

In this paper, we describe a method of optimum temperature modulation of metal oxide semiconductor (MOS) based gas sensor, operated in dynamic temperature measurement for identification of gas. The volatile organic compound (VOC) sample space consists of fourteen laboratory chemicals sampled at various concentration. We have used eleven number of gas sensors, manufactured by Figaro sensors, Jap...

This work aims to study a Stirling engine (SE) used recover the heat content of exhaust gas from an internal combustion engine. The attention has been focused on transfer between and working inside heater. Experimental tests have performed two-cylinder gamma-type coupled compression ignition using thermally insulated pipe cap. A mechanical power 0.275 kW at 900 rpm SE rotational speed was obtai...

The Centers for Disease Control and Prevention hosted a workshop to formulate recommendations for the control of invasive group A streptococcal (GAS) disease among household contacts of persons with invasive GAS infections and for responding to postpartum and postsurgical invasive GAS infections. Experts reviewed data on the risk of subsequent invasive GAS infection among household contacts of ...

zno and zno: mn nanocrystals were synthesized via reverse micelle method. the structural properties of nanocrystals were investigated by xrd. the xrd results indicated that the synthesized nanocrystals had a pure wurtzite (hexagonal phase) structure. resistive gas sensors were fabricated by providing ohmic contacts on the tablet obtained from compressed nanocrystals powder and the installation ...

A monolithic CMOS microhotplate-based conductance-type gas sensor system is described. A bulk micromachining technique is used to create suspended microhotplate structures that serve as sensing film platforms. The thermal properties of the microhotplates include a 1-ms thermal time constant and a 10 C mW thermal efficiency. The polysilicon used for the microhotplate heater exhibits a temperatur...