This paper presents a two-dimensional analytical model for low-temperature cylindrical heat pipes. A closed-form solution which incorporates liquid±vapor interfacial hydrodynamic coupling and non-Darcian transport through the porous wick for the ®rst time, is obtained for predicting the vapor and liquid velocity and pressure distributions. In addition, the steady-state vapor and wall temperatur...

Water vapor jet assisted metal cutting is a pollution-free green cutting technique. This paper has developed a three-dimensional finite element model of water vapor jet assisted cutting in order to understand the influence of its cooling and lubricating effect on cutting process. The cooling effect of water vapor jet is modeled with a convective heat transfer coefficient. A window with the temp...

We show here that stratospheric water vapor variations play an important role in the evolution of our climate. This comes from analysis of observations showing that stratospheric water vapor increases with tropospheric temperature, implying the existence of a stratospheric water vapor feedback. We estimate the strength of this feedback in a chemistry-climate model to be +0.3 W/(m(2)⋅K), which w...

A dual frequency ground-based radiometer operating in the 1 to 1.4 cm wavelength range can provide continuous measurements of integrated water vapor and cloud liquid water. Using climatological data, the accuracy of the vapor and liquid determinations is estimated as a function of cloud amount. Limiting factors in the water determination are uncertainties in water vapor absorption coefficients ...

To understand the role of water vapor feedback in unperturbed surface temperature variability, a version of the Geophysical Fluid Dynamics Laboratory coupled ocean–atmosphere model is integrated for 1000 yr in two configurations, one with water vapor feedback and one without. For all spatial scales, the model with water vapor feedback has more low-frequency (timescale $ 2 yr) surface temperatur...

Ground-based measurements of meteorological parameters and water-soluble organic carbon in the gas(WSOCg) and particle (WSOCp) phases were carried out in Atlanta, Georgia, from May to September 2007. Fourteen separate events were observed throughout the summer in which WSOCp and water vapor concentrations were highly correlated (average WSOCp-water vapor r = 0.92); however, for the entire summe...

[1] At present, two Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on board the NASA Terra and Aqua Spacecraft platforms are operational for global remote sensing of the land, ocean, and atmosphere. In this paper, we describe an algorithm for water vapor derivations using several MODIS near-IR channels. The derivations are made over areas that have reflective surfaces in the ...

An analytical model is developed for the startup transient of asymmetrical flat-plate and diskshaped heat pipes. The model solves the proper transient heat conduction equations for the heat pipe wall and liquid-wick regions. A quasi-steady state, pseudo three-dimensional approximation is used for the vapor transi’ent behavior. The heat transfer within the wall and liquid-wick regions is coupled...