A primary objective of the Engineered Barrier Design Test (EBDT) at the Yucca Mountain Exploratory Shaft Test Site is to examine how the variably saturated, fractured rock mass surrounding the waste package will respond hydrothermally to heating, cooling, and infiltration. The EBDT will include several partialand/or full-scale electrical heaters to simulate the thermal load generated by the was...

A controlled, randomised study was performed to evaluate the efficacy of treatment with heater probe in the prevention of rebleeding from peptic ulcer with a non-bleeding visible vessel. One hundred and one patients were randomised into two groups: patients to be treated by heater probe (n = 51) and controls without active treatment (n = 50). In the heater probe group rebleeding occurred in fiv...

Of late, battery-driven high-performance gas sensors have gained acceptability in practical usage, whose atomic-scale structure has been revealed by μ-fluorescence X-ray absorption fine structure analysis. We studied the chemical distribution of Pd species in the Pd/Al2O3 catalyst overlayer in the real gas sensor at various degrees of deterioration. In a freshly prepared sensor, all Pd species ...

Effects of surface chemical modification with sodium silicate on the gas-sensing properties of F-doped SnO2 gas sensor designed and fabricated employing micro-electro mechanical system (MEMS) technology were investigated. Gas sensing properties of the sensor were checked against combustible gases like H2, CO, CH4 and C3H8 at a heater voltage of 0.7 V. The H2 sensitivity of the surface modified ...

A membrane-based gas humidification apparatus was employed to actively manage the amount of water vapor entrained in the reactant gas supplied to a fuel cell stack. The humidification system utilizes a gas bypass and a series of heaters to achieve accurate and fast humidity and temperature control. A change in fuel cell load induces a reactant mass flow rate disturbance to this humidification s...

This work describes the implementation and the modeling of an infrared gas sensor with pulse delta-sigma sensing architecture. Beyond the conventional technique of constant periodic heating of infrared light source, our proposed delta-sigma architecture with closed-loop feedback system is built with the hybrid combination of a CO2 infrared sensor with a specific wavelength filter, an infrared M...

Conditioning of the insert inside a hollow cathode is believed to be important to ensure reliable discharge initiation and subsequent cathode operation. The desorption of contaminates is reported from hollow cathodes as a function of heater power to quantify cathode conditioning characteristics and identify factors that might prevent the fast initiation of a discharge. In addition to conditioni...

The 3ω method for measurement of thermal conductivity of a solid usually consists of a strip heater above a substrate, and the method is based on an approximate solution of the heat conduction problem in which the heater thickness is neglected. We establish a two-dimensional heat conduction model for the heater-on-substrate 3ω method which takes into account the finite thickness of the heater. ...