The rarefied gas effect on concentration slip and on heterogeneous combustion in microscale chemical reactors was investigated. First, a concentration slip model to describe the rarefied gas effect on the species transport in microscale chemical reactors was derived from the approximate solution of the Boltzmann equation. Second, the model was verified using the direct Monte-Carlo method for th...

The gas assisted injection moulding (GAIM) process has benefits realised through material saving, improved product performance and lower capital cost of machinery. This important process is similar to conventional injection moulding in so far as polymer melt enters a cavity under pressure. However, before the melt completely fills the cavity, nitrogen gas is introduced into the melt at high pre...

For the design of a special gas-flow proportional counter intended for a new on-line measurement method of airborne radon (Rn) concentration, the amplification properties of four gas compositions were investigated in air-mixed Argon-propane (1%)-based proportional counters. These four gas compositions are: Ar-C3H8 (1%); Ar-C3H8 (1%) + 2% air; Ar-C3H8 (1%) + 6% air and Ar-C3H8 (1%) + 10% air. Th...

We integrated an air-cooled cold trap (CT) channel in a microfluidic device for monitoring airborne benzene, toluene, ethylbenzene, and xylene (BTEX) gases and demonstrated its effect on improving the detection limit of the microfluidic device. The device consists of concentration and detection cells formed of 3 x 1 cm Pyrex plates. We first introduced a sample gas into the concentration cell, ...

In this article the main objective is to perform a search in an unknown area with multiple robots in order to determine the region with highest chemical gas concentration as well as to build the chemical gas concentration map. The searching and map building tasks are accomplished by using mobile robots equipped with smart transducers for gas sensing. Robots perform the search autonomously by us...

Objective(s) Herbal waters are extensively used in most parts of Iran including Mashhad. Visiting a patient with total blindness due to daily ingestion of around 200 ml of herbal water (Plant forty water) per day for six months was the rational for methanol determination in all herbal waters available in Mashhad markets. Materials and Methods A total of two hundred and nineteen bottles of he...

A fluidized bed reactor with ultraviolet lamp and TiO2/silica photo-catalyst prepared in our laboratory was used as a photo-reactor to degrade toluene in a simulated toluene-air mixture. The effects of operating parameters including initial toluene concentration, superficial gas velocity, ultraviolet light intensity and catalyst bed height on degradation rate of toluene have been investigated i...

During Leg 204, we cored and logged nine sites on the Oregon continental margin to determine the distribution and concentration of gas hydrates in an accretionary ridge and adjacent slope basin, investigate the mechanisms that transport methane and other gases into the gas hydrate stability zone (GHSZ), and obtain constraints on physical properties of gas hydrates in situ. A three-dimensional s...

To investigate flow of gas mixtures through micro channel in detail, the tangential momentum accommodation coefficients of each species for gaseous mixtures were determined by analyzing the Couette flow problem of a slightly rarefied gas between two walls. The molecular dynamics (MD) method for the interaction of gas molecule with the wall surface is combined with the DSMC method for the motion...

The key point of flue gas spectra analysis is how to separate and calculate the concentration of different kinds of gas, which is from continuous mixed gas absorption spectrum signal. In this paper, a new iteration of the recursive algorithm is put forward on the basis of Lambert-Beer's law. This algorithm, using the superposition of the absorbance, achieves data nonlinear fitting. It takes the...