BACKGROUND The incidence of early childhood acute respiratory infections (ARIs) has been associated with aspects of the indoor environment. In recent years, public awareness about some of these environmental issues has increased, including new laws and subsequent changes in occupant behaviours. This New Zealand study investigated current exposures to specific risk factors in the home during the...

One of the key components of a chemical gas sensor is a MEMS micro-heater. Micro-heaters are used in both semiconductor gas sensors and NDIR gas sensors; however they each require different heat dissipation characteristics. For the semiconductor gas sensors, a uniform temperature is required over a wide area of the heater. On the other hand, for the NDIR gas sensor, the micro-heater needs high ...

natural convection heat transfer from a tube bundle in the indirect water bath heaters is investigated. a computer-code is used for the solution of the governing equations of mass, momentum and energy transfer based on the simple-c algorithm. simulations are carried out for the gas pressure station heater of kermanshah city with various tube bundle arrangements. in order to validate the numeric...

Based on an effective energy conversion method between gas enthalpy and thermal radiation, a multi-layered type of porous air heater has been proposed. In the five layered structure which is analyzed in this work, there are five porous layers which are separated by four quartz glass windows. The main layer operates as a porous radiant burner that products a large amount of thermal radiative ene...

the growth of the electrical energy consumption form one side and the bounded available fossil fuel and other limitations from the other side, makes the thermal power plants upgrading as a main demand in the world. decreasing the internal energy consumption, increasing the performance and the output power with the minimum costs are the important targets of the power plants retrofitting. nowaday...

A pulsed arc heater was designed and manufactured at Centrospazio to equip a new hypersonic high-enthalpy blow-down wind tunnel capable of producing flows with a specific total enthalpy up to 2.5 MJ/kg. The heater mainly consists of two coaxial electrodes, separated by a constrictor, and a plenum chamber. The flow is heated by an electric arc ignited between the electrodes and sustained by the ...

It is demonstrated how a commercially available MEMS thermopile infrared radiation sensor can be used as thermal conductivity gas detector (TCD). Since a TCD requires a heater while IR-thermopile sensors have no integrated heater, the thermopile itself is used as heater and temperature sensor at the same time. It is exposed to the measured gas environment in its housing. It is shown that, by us...