Carbonation is one of the major deteriorations that accelerate steel corrosion in reinforced concrete structures. Many mathematical/numerical models of the carbonation process, primarily diffusion-reaction models, have been established to predict the carbonation depth. However, the mass transfer of carbon dioxide in porous concrete includes molecular diffusion and convection mass transfer. In p...

As proposed spacecraft and their associated thrusters have become smaller, technology has been developed to meet the demand for performance measurements for the extremely low force levels produced. For such thrusters, it is also desirable to measure the mass changes resulting from the utilization of propellant associated with either the steady state thrust or transient impulses. A thrust stand ...

A new method combining axisymmetric drop shape analysis (ADSA) and a captive bubble (CB) is proposed to study the effect of surfactant on interfacial gas transfer. In this method, gas transfer from a static CB to the surrounding quiescent liquid is continuously recorded for a short period (i.e., 5 min). By photographical analysis, ADSA-CB is capable of yielding detailed information pertinent to...

Heat or mass transfer from spherical particles in oscillatory flow has important applications in combustion and spray drying. This work provides a parametric investigation of drag forces experienced by, and transport of a passive scalar from, an isolated rigid fixed sphere in steady and oscillatory axisymmetric flows. At Schmidt ~Prandtl! number of 1, oscillatory flows with Reynolds numbers in ...

Most of the research concerning production systems is so far limited to the assessment of the steady-state throughput despite the impact of the parameter variability on the overall performance of such systems. In this paper, we propose an analytical model to assess the variance of the throughput of homogeneous transfer lines subject to operation-dependant failures. The transfer lines subject of...

A model for the physical description of water transport through steady-state permeation and dynamic sorption within perfluoro-sulfonic acid (PFSA) membranes has been developed. broad experimental campaign is conducted on several membranes, belonging to Aquivion class, varying both in thickness equivalent weight ( EW ). The data have used calibrate validate find correlations mass-transfer proper...

the steady state effect of vertical fins is assessed on a photovoltaic/thermal solar air heater having a double pass configuration in which fins are placed in the lower channel perpendicular to the direction ofair flow. air passes through the upper channel of the air heater and before passing in the opposite direction through the lower channel. the effects of design, climatic and operating para...