BACKGROUND Previous research by the authors found evidence that up to 10% of particular household categories may be exposed to elevated carbon monoxide (CO) concentrations from poor quality gas appliance installations. The literature suggests certain neurological symptoms are linked to exposure to low levels of CO. This paper addresses the hypothesis that certain self-reported neurological symp...

A microprocessor-controlled automatic extractor, (PREMTM I) is described with which lipophilic components may be extracted from physiological fluids by means of a selective, solid-phase extraction cartridge, and the extracts presented in dry form for subsequent analysis. This instrument has been successfully evaluated for the extraction of phenobarbital, primidone, and phenytoin from human seru...

AIMS To explore the association of household gas cooking and respiratory illnesses in preschool children and their relation to outdoor air pollution. METHODS Cross-sectional study among households that used gas stoves for cooking in two housing estates with contrasting air qualities in Hong Kong. A structured questionnaire was administered to parents of 426 children aged 0-6 years on their ex...

The key component in trace analysis is the concentration step where the analytes are accumulated before the analysis. This paper presents the development of a micromachined microconcentrator that can be used to enhance the sensitivity of microsensors. Another application demonstrated here is a concentrator-injector for a gas chromatograph. The microconcentrators were fabricated on a 6-in. silic...

In this paper we describe a novel long-term microhotplate temperature sensor calibration technique suitable for Built-In Self Test (BIST). The microhotplate thermal resistance (thermal efficiency) and the thermal voltage from an integrated platinum-rhodium thermocouple were calibrated against a freshly calibrated four-wire polysilicon microhotplate-heater temperature sensor (heater) that is not...

The 3ω method is popular for thermal conductivity measurements. It consists of a strip heater above a substrate, and the results are usually based on approximate solutions of the heat conduction equation for simplified heating in which the heater is assumed to be a thin plate. Through numerical studies, it is found that a finite heater thickness has an effect on the value of the thermal conduct...

The level of income the inhabitants in a township has an impact on potential to have adequate access electricity. bulk domestic energy sources needed residential buildings is derived from electrical energy. In South Africa, base load electricity coal thermal power plants. However, environmental associated with combustion plants cause for concern. This study was designed identify common mode san...