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Heat Transfer Applications
Published in Theodore Louis, Behan Kelly, Introduction to Optimization for Environmental and Chemical Engineers, 2018
Vapor–liquid changes are referred to as condensation when the vapor is condensing and vaporization when liquid is vaporizing. Liquid–solid changes are referred to as melting when the solid melts to liquid and freezing when a liquid solidifies. Vapor–solid changes are referred to as sublimation. One should also note that there are enthalpy effects associated with a phase change of a solid to another solid form; however, this enthalpy effect is small compared to the other effects mentioned previously. Finally, vapor–liquid changes are of primary interest to the practicing environmental and chemical engineer. This leads to the subject of steam tables.
Water Properties
Published in Louis Theodore, R. Ryan Dupont, Water Resource Management Issues, 2019
Louis Theodore, R. Ryan Dupont
Vapor-liquid changes are referred to as condensation when the vapor is condensing and vaporization when liquid is vaporizing. Liquid-solid changes are referred to as melting when the solid melts to liquid and freezing when a liquid solidifies. Vapor-solid changes are referred to as sublimation. One should also note that there are enthalpy effects associated with a phase change of a solid to another solid form; however, this enthalpy effect is small compared to the other effects mentioned previously. Specific volume, enthalpy, and entropy data for saturated steam, superheated steam, and steam-ice mixtures are provided in Tables 3.3 through 3.5, respectively (Keenan and Keyes 1930; Jones and Hawkins 1960; Van Wylen and Sonntag 1965). Table 3.3provides properties for saturated steam/water between 32° F and 700° F. Table 3.4 contains properties for superheated steam between 1.0 psia and 600 psia. Table 3.5 provides properties for saturated steam-ice between 32° F and −40° F. Lowercase notation is employed for specific volume (v), enthalpy (h), and entropy (s) because the values are listed on a mass basis. English units are employed throughout the three tables. Those interested in using these values with other units should refer to the Appendix for the appropriate conversion constants. Linear interpolation should be employed where necessary. Additional data are available in the three cited references. Other physical properties are addressed in the next section.
Terms and Definitions
Published in Rick Houghton, William Bennett, Emergency Characterization of Unknown Materials, 2020
Rick Houghton, William Bennett
Melting point is the temperature at which a solid melts to a liquid. Freezing point is the temperature at which a liquid solidifies. Both terms indicate the same temperature for a material. Melting and freezing points assume standard pressure of 1 atmosphere, unless otherwise noted.
A comparative study of long-time series of global-scale albedo products
Published in International Journal of Digital Earth, 2023
Li Mengyao, Liu Qiang, Qu Ying
Albedo is defined as the ratio of the reflected solar radiation to the incident solar radiation (Dickinson 1983), which is an uncertain factor in the earth-air system. It plays an important role in the study of global or regional climate change (Knorr and Chnitzler 2001; Valero and Charlson 2008; Zhang et al. 2010). On the global scale, as global temperatures rise, ice and sea ice at high latitudes melt massively, resulting in lower albedo and more solar radiation absorption on the surface, which, in turn, exacerbates temperature rises, creating a feedback process that has attracted much attention (Ingram, Wilson, and Mitchell 1989; Curry and Schramm 1995; Winton 2008). Deforestation causes changes in surface albedo, evapotranspiration, and surface roughness, thereby triggering two opposing types of forcing mechanisms, radiative forcing and non-radiative forcing, with a net cooling effect on the earth (Bala et al. 2007; Davin and De Noblet-Ducoudré 2010). At a regional scale, the expansion of biofuels causes regional climate change by changing surface parameters such as albedo (Loarie et al. 2011), with boreal forests generating positive climate forcing through albedo and mitigating regional warming (Bonan 2008). Therefore, using the relevant data to record the spatial and temporal changes of albedo is helpful to better study the environment and climate change.
Sea ice conditions and navigability through the Northeast Passage in the past 40 years based on remote-sensing data
Published in International Journal of Digital Earth, 2021
Miao Yu, Peng Lu, Zhiyuan Li, Zhijun Li, Qingkai Wang, Xiaowei Cao, Xiaodong Chen
Ice conditions are dominant factors that influence the navigable period (NP) of Arctic sea routes; thus it is necessary to understand the seasonal and spatial changes of sea ice clearly. Changes in sea ice are associated with many factors, including dynamic and thermodynamic processes, which causes extensive researches (Deser and Teng 2008; Ballinger and Sheridan 2015; Peng et al. 2018). The effects of the dynamic processes attributed to the force of wind and ocean currents not only change the distribution of sea ice, but also enhance sea ice melt via thermodynamic effects (Ogi and Wallace 2012; Schreiber and Serreze 2020). In turn, thermodynamic processes are mainly driven by absorbed solar irradiance, ocean heat flux and air temperature (Tair), which affect sea ice melt and freeze (Kapsch et al. 2016; Mortin et al. 2016). Meanwhile, melt onset has a significant impact on the amount of solar energy absorbed by ice and the upper ocean, which in turn affects the loss of sea ice (Stroeve et al. 2014).
Investigation of the material properties influence on thermophysical processes at the action of a laser pulse
Published in Welding International, 2020
In mathematical modelling, two steps of the thermal process are examined: Heating of the material to the melting point (solid phase);Heating of the melt and further penetration of the solid part of the material (liquid phase).Heating of the melt, penetration of the solid part and the start of intensive evaporation and boiling of the material (evaporation and boiling phase).