Academic literature on the topic 'Water vapor density'
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Journal articles on the topic "Water vapor density"
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Pokrovski, Gleb S., Jacques Roux, and Jean-Claude Harrichoury. "Fluid density control on vapor-liquid partitioning of metals in hydrothermal systems." Geology 33, no. 8 (August 1, 2005): 657–60. http://dx.doi.org/10.1130/g21475ar.1.
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Abstract Hot aqueous fluids, both vapor and saline liquid, are primary transporting media for metals in hydrothermal-magmatic systems. Despite the growing geological evidence that the vapor phase, formed through boiling of magmatic ore-bearing fluids, can selectively concentrate and transport metals, the physical-chemical mechanisms that control the metal vapor-liquid fractionation remain poorly understood. We performed systematic experiments to investigate the metal vapor-liquid partitioning in model water-salt-gas systems H2O-NaCl-KCl-HCl at hydrothermal conditions. Measurements show that equilibrium vapor-liquid fractionation patterns of many metals are directly related to the densities of the coexisting vapor and liquid phases. Despite differences in the vapor-phase chemistry of various metals that form hydroxide, chloride, or sulfide gaseous molecules of contrasting volatile properties, water-solute interaction is a key factor that controls the metal transfer by vapor-like fluids in Earth's crust. These findings allow quantitative prediction of the vapor-liquid distribution patterns and vapor-phase metal transport in a wide range of conditions. Our density model accounts well for the vapor-brine distribution patterns of Na, Si, Fe, Zn, As, Sb, and Ag observed in fluid inclusions from magmatic-hydrothermal deposits. For Au and Cu, the partitioning in favor of the liquid phase, predicted in a sulfur-free system, contrasts with the copper and gold enrichment observed in natural vapor-like inclusions. The formation of stable complexes of Cu and Au with reduced sulfur may allow for their enhanced transport by sulfur-enriched magmatic-hydrothermal vapors.
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Konyukhov, V. K., and N. I. Valentinova. "Transfer of water molecules in presence of low density water vapor." Journal of Physics: Conference Series 1560 (June 2020): 012018. http://dx.doi.org/10.1088/1742-6596/1560/1/012018.
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Song, Kun, Xichuan Liu, Taichang Gao, and Peng Zhang. "Estimating Water Vapor Using Signals from Microwave Links below 25 GHz." Remote Sensing 13, no. 8 (April 7, 2021): 1409. http://dx.doi.org/10.3390/rs13081409.
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Water vapor is a key element in both the greenhouse effect and the water cycle. However, water vapor has not been well studied due to the limitations of conventional monitoring instruments. Recently, estimating rain rate by the rain-induced attenuation of commercial microwave links (MLs) has been proven to be a feasible method. Similar to rainfall, water vapor also attenuates the energy of MLs. Thus, MLs also have the potential of estimating water vapor. This study proposes a method to estimate water vapor density by using the received signal level (RSL) of MLs at 15, 18, and 23 GHz, which is the first attempt to estimate water vapor by MLs below 20 GHz. This method trains a sensing model with prior RSL data and water vapor density by the support vector machine, and the model can directly estimate the water vapor density from the RSLs without preprocessing. The results show that the measurement resolution of the proposed method is less than 1 g/m3. The correlation coefficients between automatic weather stations and MLs range from 0.72 to 0.81, and the root mean square errors range from 1.57 to 2.31 g/m3. With the large availability of signal measurements from communications operators, this method has the potential of providing refined data on water vapor density, which can contribute to research on the atmospheric boundary layer and numerical weather forecasting.
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Wang, H., X. Liu, K. Chance, G. González Abad, and C. Chan Miller. "Water vapor retrieval from OMI visible spectra." Atmospheric Measurement Techniques 7, no. 6 (June 30, 2014): 1901–13. http://dx.doi.org/10.5194/amt-7-1901-2014.
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Abstract. There are distinct spectral features of water vapor in the wavelength range covered by the Ozone Monitoring Instrument (OMI) visible channel. Although these features are much weaker than those at longer wavelengths, they can be exploited to retrieve useful information about water vapor. They have an advantage in that their small optical depth leads to fairly simple interpretation as measurements of the total water vapor column density. We have used the Smithsonian Astrophysical Observatory (SAO) OMI operational retrieval algorithm to derive the slant column density (SCD) of water vapor using the 430–480 nm spectral region after extensive optimization. We convert from SCD to vertical column density (VCD) using the air mass factor (AMF), which is calculated using look-up tables of scattering weights and assimilated water vapor profiles. Our Level 2 product includes not only water vapor VCD but also the associated scattering weights and AMF. In the tropics, our standard water vapor product has a median SCD of 1.3 × 1023 molecules cm−2 and a median relative uncertainty of about 11%, about a factor of 2 better than that from a similar OMI algorithm that uses a narrower retrieval window. The corresponding median VCD is about 1.2 × 1023 molecules cm−2. We have examined the sensitivities of SCD and AMF to various parameters and compared our results with those from the GlobVapour product, the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Aerosol Robotic NETwork (AERONET).
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Wang, H., X. Liu, K. Chance, G. Gonzalez Abad, and C. Chan Miller. "Water vapor retrieval from OMI visible spectra." Atmospheric Measurement Techniques Discussions 7, no. 1 (January 22, 2014): 541–67. http://dx.doi.org/10.5194/amtd-7-541-2014.
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Abstract. There are distinct spectral features of water vapor in the wavelength range covered by the Ozone Monitoring Instrument (OMI) visible channel. Although these features are much weaker than those at longer wavelengths, they can be exploited to retrieve useful information about water vapor. They have an advantage in that their small optical depth leads to fairly simple interpretation as measurements of the total water vapor column density. We have used the Smithsonian Astrophysical Observatory (SAO)'s OMI operational retrieval algorithm to derive the Slant Column Density (SCD) of water vapor from OMI measurements using the 430–480 nm spectral region after extensive optimization of retrieval windows and parameters. The Air Mass Factor (AMF) is calculated using look-up tables of scattering weights and monthly mean water vapor profiles from the GEOS-5 assimilation products. We convert from SCD to Vertical Column Density (VCD) using the AMF and generate associated retrieval averaging kernels and shape factors. Our standard water vapor product has a median SCD of ~ 1.3 × 1023 molecule cm−2 and a median relative uncertainty of ~ 11% in the tropics, about a factor of 2 better than that from a similar OMI algorithm but using narrower retrieval window. The corresponding median VCD is ~ 1.2 × 1023 molecule cm−2. We have also explored the sensitivities to various parameters and compared our results with those from the Moderate-resolution Imaging Spectroradiometer (MODIS) and the Aerosol Robotic NETwork (AERONET).
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Kim, Sun Min, Hyun Chul Kim, Chang-Yeoul Kim, Daeho Yoon, and Eunhae Koo. "The Relationship Between Water Transmission Rate and Defects on the Film Based on the Defect Analysis Using Fluorescent Calcein Probe." Journal of Nanoscience and Nanotechnology 20, no. 9 (September 1, 2020): 5469–72. http://dx.doi.org/10.1166/jnn.2020.17619.
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The most critical issue on flexible electronics such as organic solar cell, OLED, and flexible displays, is the protection of core active materials from the degradation by water and oxygen. The water vapor transmission rate (WVTR), the main characteristics of barrier films, is closely related to defect density in inorganic layers constructed in the film. In this study, a calcein fluorescent probe is used to examine the relationship between the water vapor transmission rate (WVTR) and the defect density of the film coated the inorganic oxide layer. By using the fluorescence characteristics of calcein dye molecules, the calcein can be used for the evaluation of water vapor transmission rate. The result shows that the defect density is linearly increasing with the water vapor transmission rate of barrier films. Furthermore, it is shown that the defect density is inversely proportional to the thickness of the inorganic layer of Al2O3. Based on these results, it is suggested that the defect density measurement of the inorganic layer can predict the water vapor transmission rate of the barrier film.
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Mei, Yuan, Weihua Liu, A. A. Migdiov, Joël Brugger, and A. E. Williams-Jones. "CuCl Complexation in the Vapor Phase: Insights from Ab Initio Molecular Dynamics Simulations." Geofluids 2018 (2018): 1–12. http://dx.doi.org/10.1155/2018/4279124.
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We investigated the hydration of the CuCl0 complex in HCl-bearing water vapor at 350°C and a vapor-like fluid density between 0.02 and 0.09 g/cm3 using ab initio molecular dynamics (MD) simulations. The simulations reveal that one water molecule is strongly bonded to Cu(I) (first coordination shell), forming a linear [H2O-Cu-Cl]0 moiety. The second hydration shell is highly dynamic in nature, and individual configurations have short life-spans in such low-density vapors, resulting in large fluctuations in instantaneous hydration numbers over a timescale of picoseconds. The average hydration number in the second shell (m) increased from ~0.5 to ~3.5 and the calculated number of hydrogen bonds per water molecule increased from 0.09 to 0.25 when fluid density (which is correlated to water activity) increased from 0.02 to 0.09 g/cm3 (fH2O 1.72 to 2.05). These changes of hydration number are qualitatively consistent with previous solubility studies under similar conditions, although the absolute hydration numbers from MD were much lower than the values inferred by correlating experimental Cu fugacity with water fugacity. This could be due to the uncertainties in the MD simulations and uncertainty in the estimation of the fugacity coefficients for these highly nonideal “vapors” in the experiments. Our study provides the first theoretical confirmation that beyond-first-shell hydrated metal complexes play an important role in metal transport in low-density hydrothermal fluids, even if it is highly disordered and dynamic in nature.
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Ding, Nan, Shubi Zhang, and Qiuzhao Zhang. "New parameterized model for GPS water vapor tomography." Annales Geophysicae 35, no. 2 (February 28, 2017): 311–23. http://dx.doi.org/10.5194/angeo-35-311-2017.
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Abstract. Water vapor is the basic parameter used to describe atmospheric conditions. It is rarely contained in the atmosphere during the water cycle, but it is the most active element in rapid space–time changes. Measuring and monitoring the distribution and quantity of water vapor is a necessary task. GPS tomography is a powerful means of providing high spatiotemporal resolution of water vapor density. In this paper, a spatial structure model of a humidity field is constructed using voxel nodes, and new parameterizations for acquiring data about water vapor in the troposphere via GPS are proposed based on inverse distance weighted (IDW) interpolation. Unlike the density of water vapor that is constant within a voxel, the density at a certain point is determined by IDW interpolation. This algorithm avoids the use of horizontal constraints to smooth voxels that are not crossed by satellite rays. A prime number decomposition (PND) access order scheme is introduced to minimize correlation between slant wet delay (SWD) observations. Four experimental schemes for GPS tomography are carried out in dry weather from 2 to 8 August 2015 and rainy days from 9 to 15 August 2015. Using 14 days of data from the Hong Kong Satellite Positioning Reference Station Network (SatRef), the results indicate that water vapor density derived from 4-node methods is more robust than that derived from that of 8 nodes or 12 nodes, or that derived from constant refractivity schemes and the new method has better performance under stable weather conditions than unstable weather (e.g., rainy days). The results also indicate that an excessive number of interpolations in each layer reduce accuracy. However, the accuracy of the tomography results is gradually reduced with increases in altitude below 7000 m. Moreover, in the case of altitudes between 7000 m and the upper boundary layer, the accuracy can be improved by a boundary constraint.
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Zhao, Qingzhi, Yibin Yao, and Wanqiang Yao. "Troposphere Water Vapour Tomography: A Horizontal Parameterised Approach." Remote Sensing 10, no. 8 (August 7, 2018): 1241. http://dx.doi.org/10.3390/rs10081241.
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Global Navigation Satellite System (GNSS) troposphere tomography has become one of the most cost-effective means to obtain three-dimensional (3-d) image of the tropospheric water vapour field. Traditional methods divide the tomography area into a number of 3-d voxels and assume that the water vapour density at any voxel is a constant during the given period. However, such behaviour breaks the spatial continuity of water vapour density in a horizontal direction and the number of unknown parameters needing to be estimated is very large. This is the focus of the paper, which tries to reconstruct the water vapor field using the tomographic technique without imposing empirical horizontal and vertical constraints. The proposed approach introduces the layered functional model in each layer vertically and only an a priori constraint is imposed for the water vapor information at the location of the radiosonde station. The elevation angle mask of 30° is determined according to the distribution of intersections between the satellite rays and different layers, which avoids the impact of ray bending and the error in slant water vapor (SWV) at low elevation angles on the tomographic result. Additionally, an optimal weighting strategy is applied to the established tomographic model to obtain a reasonable result. The tomographic experiment is performed using Global Positioning System (GPS) data of 12 receivers derived from the Satellite Positioning Reference Station Network (SatRef) in Hong Kong. The quality of the established tomographic model is validated under different weather conditions and compared with the conventional tomography method using 31-day data, respectively. The numerical result shows that the proposed method is applicable and superior to the traditional one. Comparisons of integrated water vapour (IWV) of the proposed method with that derived from radiosonde and European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim data show that the root mean square (RMS)/Bias of their differences are 3.2/−0.8 mm and 3.3/−1.7 mm, respectively, while the values of traditional method are 5.1/−3.9 mm and 6.3/−5.9 mm, respectively. Furthermore, the water vapour density profiles are also compared with radiosonde and ECMWF data, and the values of RMS/Bias error for the proposed method are 0.88/0.06 g/m3 and 0.92/−0.08 g/m3, respectively, while the values of the traditional method are 1.33/0.38 g/m3 and 1.59/0.40 g/m3, respectively.
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Xi, Erte, Sean M. Marks, Suruchi Fialoke, and Amish J. Patel. "Sparse sampling of water density fluctuations near liquid-vapor coexistence." Molecular Simulation 44, no. 13-14 (April 21, 2018): 1124–35. http://dx.doi.org/10.1080/08927022.2018.1457218.
Full textDissertations / Theses on the topic "Water vapor density"
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Lekic, Dragan. "HotHumiBox, ett provelement mellan två kammare." Thesis, Linnéuniversitetet, Institutionen för byggteknik (BY), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-80509.
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HotHumiBox är en försöksutrustning som finns på Linnéuniversitetet och som ska ge bättre kunskap och förståelse om hur fukt och temperatur varierar i en provkropp monterad mellan två kammare där klimatet kan styras var för sig. Syftet med examensarbetet är att undersöka om HotHumiBoxen fungerar väl och huruvida den kan börja användas i undervisningen i olika kurser inom institutionen för byggteknik på Linnéuniversitetet, bl.a. i samband med demonstrationslaborationer vid föreläsningar om fukt. För att genomföra arbetet har mätningar med tre olika klimat utförts på ett provelement som motsvarar en yttervägg som kan finnas i nybyggda typhus. Resultatet av mätningar utförda med HotHumiBoxen presenteras i form av tabeller och diagram och jämförs slutligen med beräkningar av fukt- och temperaturtillstånd. Jämförelsen mellan mätningar och beräkningar visar att givarna som styr klimatet i båda kamrarna visar mycket bra resultat. Däremot visar majoriteten av givarna i provelementet antingen lite för höga eller för låga värden för att resultatet ska anses som tillfredställande. För att få en bekräftelse på att HotHumiBoxen fungerar väl rekommenderas därför att ytterligare mätningar görs.HotHumiBox is an experimental equipment that is available at Linnaeus University and is supposed to provide better knowledge and understanding about the way moisture and temperature varies in a building element installed between two chambers in which the climate can be controlled separately. The purpose of this work is to investigate whether the HotHumiBox works well and whether it can be used at various courses at the Department of Building Technology at Linnaeus University, such as demonstration laboratory experiments at lectures on moisture. Measurements with three different climates were performed on a building element that corresponds to a wall that could be installed in modern houses. The results of the HotHumiBox measurements are being presented in tables and diagrams and are being compared with moisture and temperature calculations. The comparison between measurements and calculations shows that the sensors which control the climate in both chambers show very good results. On the other hand, the majority of the sensors in the test element show either too high or too low values for the result to be considered as satisfactory. Therefore, it is recommended that some more tests and measurements are done before it can be concluded that the HotHumiBox work well.
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Marboutin, Yves. "Contribution à l'étude et à l'optimisation d'une torche à plasma à arc non transféré." Thesis, Clermont-Ferrand 2, 2012. http://www.theses.fr/2012CLF22256/document.
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Le contexte de cette thèse est la production du vecteur énergétique hydrogène par thermolyse de la vapeur d’eau consistant en la dissociation de la molécule H2O en oxygène (O) et hydrogène (H). Le dispositif employé est une torche à plasma d’arc non transféré développée au LAEPT. Après l’exposition de la théorie sur la physique des plasmas et la spectrométrie d’émission atomique nécessaire à l’exploitation des mesures, cette thèse présente l’évolution de la torche à plasma ainsi que son environnement nécessitée par la présence de gaz instables et explosifs. Les mesures des différentes grandeurs électriques, hydrauliques et spéctrométriques ont permis la détermination des caractéristiques physique et chimique d’un plasma formé d’un mélange de vapeur d’eau – d’argon. La détermination de grandeurs telles que la température du jet plasma, la conductivité électrique, l’enthalpie massique et la densité électronique, est basée sur la comparaison entre expérimentation et théorieThe context of this thesis is the production of hydrogen as an energy vector by steam thermolysis consisting in the dissociation of H2O molecule into oxygen (O) and hydrogen (H). The process used is a plasma torch device developed by the LAEPT. After presenting the theory of plasma physics and atomic emission spectroscopy which will help to make the most of the measured realized, this thesis will show the evolution of the plasma torch device and the experimental environment required to work with explosive and unstable gases. Some measurements like electrical, hydraulic and spectroscopy magnitudes made it possible to determine the chemical and physical characteristics of a water vapor – argon plasma. A comparison between experiments and theoretical knowledge will enable to determine the temperature of a flow of plasma, electrical conductivity, enthalpy and the electronic density
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Gill, Yasir Q. "Preparation and characterization of polyethylene based nanocomposites for potential applications in packaging." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/18052.
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The objective of my work was to develop HDPE clay nanocomposites for packaging with superior barrier (gas and water) properties by economical processing technique. This work also represents a comparative study of thermoplastic nanocomposites for packaging based on linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and Nylon12. In this study properties and processing of a series of linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and Nylon 12 nanocomposites based on Na-MMT clay and two different aspect ratio grades of kaolinite clay are discussed.
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Vorel, Pavel. "Vlastnosti betonů s přídavkem plazmatem upravených polypropylenových vláken." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-225879.
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Master‘s thesis focuses on concrete combined with polypropylen fibres produced commercially, fibres without surface modifications and fibres modificated by plasma. Most important topic of the thesis is experimental verification of influence of plasma modificated fibres on attributes of fresh concrete and physical-mechanical attributes of solidified concrete. Based on the results of the tests perfomed on examin units compares results and anylyses applicability of different fibre surface modifications.
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Elorriaga, Montenegro Estefania. "High frequency water vapor density measurements using the beat frequency method." Thesis, 2012. http://hdl.handle.net/1957/30841.
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This document describes the design and deployment of a first generation water vapor density sensing unit, the HumiSense. This device is based on an open, air-filled capacitor which is part of a resonant circuit. The frequency of the resonant circuit mixed with a fixed frequency oscillator is the basis of the method to generate a signal that is associated to the change in water vapor density within the open capacitor with time. The physical testing results were inconclusive given that there were many unresolved artifacts in the data. Several suggestions for improving the device for future device generations were provided.Graduation date: 2013
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Jeng, Lung-Yue, and 鄭龍嶽. "A novel hybrid system in combination of water cooling and vapor compression systems for high-power density electronic cooling." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/x5j6f2.
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博士國立臺北科技大學
機電科技研究所
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To meet the high power and high-density allocation of electronic products, a new hybrid multi-channel heat sink was developed for applications with electronic heat sinks. The reliability of electronic products can be increased through the use of high efficiency heat removal and establishing a uniform temperature. The four sections of this paper are: 1. Liquid cooling system for electronic chip, 2. Vapor compression refrigeration systems for electronic chip, 3. Performance assessment of an R-134a VCRS for electronic cooling device retrofitted with the hydrocarbon mixtures, and 4. Hybrid cooling system for electronic chips. The first section determines optimal experimental parameters of nanofluids using theoretical analysis and experimental research with heat dissipation experimentation. The results have shown that adding chitosan dispersants at 0.05 wt.% in Al2O3/water nanofluid at 1.0wt.% can enhance the overall heat transfer coefficient by 17.4% when the flow rate, liquid temperature, and heating power are 2.0 L/mim, 40℃ and 150 W, respectively. The second section indicates the most suitable charged mass of R-134a refrigerant for this system can be found through conduct system testing and tuning. Finally, heat dissipation experiments using steady-state and dynamic will to be conducted. The results have shown that the optimal charged mass of R-134a refrigerant for the system is 150 g. The CPU heat source will have the best performance through heat dissipation when the evaporation temperature was 23 ℃ under without condensation. In the dynamic-state experiment, the refrigerant was detached from the two-phase zone and can be seen in the temperature of inlet and out let of the multi-channel evaporator. The superheat decreased in the suction when the refrigerant flow increased, as both contributed to system performance with heat dissipation. The third section, this paper explored the feasibility of replacement of R-134a refrigerant in VCRS electronic chip cooling systems with hydrocarbon refrigerant combined with isobutene/ propane (50:50, by mass). The results have shown that without changing any components in the original VCRS for cooling electronic chips, the margin of optimal changed mass was 46.6 (70g)～57 (85.5g) %. When HC refrigerant was charged with 53.3 % of the charged mass of R-134a, the CPU surface temperature and evaporator bottom temperatures were slightly higher than the R-134a systems and the COP increase of about 16 %. The fourth section integrated a single-phase liquid-cooling heat sink and an evaporator with two-phase flow boiling change by vapor compression cycle system into a hybrid cooling system for electronic chips. The coolant and refrigerant in these two systems were the optimal parameter of nanofluid and hydrocarbon refrigerant, as in the second and third sections of this paper. The results have shown that the best cooling capacity of hybrid cooling system for electronic chips was about 330W, and the surface temperature of the CPU and total system power consumption was 56 ℃ and 29.6 W, respectively. The maximum cooling capacity of this system was around 500 W, and the thermal resistance distribution was 0.03～0.05℃/W. The hybrid cooling system for electronic chips can go beyond existing electronic cooling system performance, with excellent heat dissipation, as well.
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Chen, Shang-Yi, and 陳尚誼. "Vapor Pressure, Density, and Viscosity Measurements of Mixed-Solvent Desiccant Systems containing Glycol (DEG/TEG/T4EG/PG/DPG/TPG) + Salt (MgCl2) + Water." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/42807792852604569371.
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碩士中原大學
化學工程研究所
98
In this work, new experimental data for vapor pressure, density, and viscosity of the mixed-solvent desiccant systems containing 40.0 wt% glycol (1) + salt (2) + water (3) were reported for temperatures up to 343.15 K (normal atmospheric condition). The considered glycols were diethylene glycol, triethylene glycol, propylene glycol, tetraethylene gloycol, dipropylene glycol and tripropylene glycol; and the salt is magnesium chloride (wt% = 4.0, 9.0, and 16.0). The vapor pressure, density, and viscosity were presented as functions of temperature and compositions. An empirical equation was used to correlate the temperature and compositional dependence of the density and viscosity data and a model based on the mean spherical approximation for aqueous electrolyte solutions incorporating the pseudo-solvent approach was used to represent the measured vapor pressure as functions of temperature and composition. Satisfactory results were obtained for both density and vapor pressure calculations.
Books on the topic "Water vapor density"
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Center, Goddard Space Flight, ed. Radiation flux tables for ICRCCM using the GLA GCM radiation codes. Greenbelt, Md: National Aeronautics and Space Administration, Goddard Space Flight Center, 1986.
Find full textBook chapters on the topic "Water vapor density"
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Parlance, Marc B., and John D. Albertson. "Evaporation : Use of Fast-Response Turbulence Sensors, Raman Lidar, and Passive Microwave Remote Sensing." In Vadose Zone Hydrology. Oxford University Press, 1999. http://dx.doi.org/10.1093/oso/9780195109900.003.0014.
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Since evaporation represents some 60% of precipitation over land surfaces, it is crucial for hydrologic purposes to know with some degree of certainty the magnitude of the water vapor flux into the atmosphere. Actual evaporation (E) from drying land surfaces is often formulated, in hydrology, as a fraction of some measure of potential evaporation (Ep), which can be written as a bulk transfer relationship: . . . Ep =CE up(qs* -q) (10.1) . . . where CE is the bulk mass transfer coefficient for water vapor, u is the mean wind speed at reference height z above the surface, r is the density of the air, q is the mean specific humidity at z, and q*s is the saturation specific humidity at the temperature of the surface (Ts) (Brutsaert, 1982, 1986).
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Gutschick, Vincent P., and Keirith A. Snyder. "Water and Energy Balances within the Jornada Basin." In Structure and Function of a Chihuahuan Desert Ecosystem. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195117769.003.0012.
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This chapter describes general characteristics and components of the energy and water balances in arid regions, with specific examples from the Jornada Basin. Various research efforts to characterize the energy and water balances and resultant carbon dioxide fluxes in the Jornada Basin are detailed. We provide a brief overview of how plant physiology interacts with energy and water balances in this region, and characterize general abiotic conditions and some physiological traits of plants in this arid region. The surface of a landscape may be considered as a layer with some amount of vegetation. More general descriptions divide the vegetation, like the soil, into layers, but the concern here is energy balance at the interface with the atmosphere. The net energy balance of the land surface is determined by inputs (radiant energy), outputs (reflection [i.e., albedo], emission of longwave radiation, convective heat transfer to the atmosphere [i.e., sensible heat flux], evapotranspiration of water [i.e., latent heat flux], and conduction of heat into soil), and changes in heat storage. The balance of these terms is adjusted as the surface temperature comes into steady state or nearly so. Increased solar input will drive surface temperatures higher until longwave emission and other losses come into a new balance. The net energy input, as inputs minus outputs, may be stated formally as an energy-balance equation . . . Rate of heat storage = S = Q+sw + Q+TIR − Q+TIR _ Q_E Q_H − Q_S, (8-1) . . . where the superscript + indicates an input, and − indicates an output or loss, and all terms are expressed as flux density in units of W/m2. Q+SW is the energy added to the surface layer by solar radiation from above. Q+TIR is the thermal infrared radiation emitted by gases in the atmosphere, principally water vapor and CO2, whereas Q_TIR is the thermal infrared radiation emitted from components of the Earth’s surface and lost back to the atmosphere. Q_E is the latent heat flux from the heat of vaporization of water vapors resulting from soil evaporation (E) and plant transpiration, generally measured as the composite evapotranspiration flux (ET).
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"Pollution of the Atmosphere." In Environmental Toxicology, edited by Sigmund F. Zakrzewski. Oxford University Press, 2002. http://dx.doi.org/10.1093/oso/9780195148114.003.0015.
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The earth’s atmosphere consists of 78% (by volume) of N2; 21% O2; about 0.033% CO2; trace amounts of noble gases, NOx, and CH3; and variable amounts of water vapor. At sea level, the amount of water vapor may vary from 0.5 g per kg of air in polar regions to more then 20 g per kg in the tropics. The standard atmosphere is a theoretical set of data that serves as a reference point for calculation of atmospheric changes due to the weather. The values are calculated for sea level conditions and correspond to a pressure of 760 mm of mercury (92.29 in., 1013.25 mbar), an air density of 1.22 kg/m3, and a temperature of 15°C (59 °F). The composition of the air within the troposphere, which is the lowest layer of the atmosphere, does not change with altitude; however, the pressure and temperature decrease with altitude. The relationship between altitude and pressure in the standard atmosphere is shown in Figure 10.1, and the relationship between altitude and temperature is shown in Figure 10.2. The rate of decrease of temperature with altitude (6.49 °C per km) is referred to as the ‘‘standard lapse rate’’. This rate is a strictly theoretical average value because the actual lapse rate varies depending on the weather. Because the air density is proportional to the pressure and inversely proportional to the temperature, it changes at the same rate as the pressure does. The atmosphere is divided into troposphere, stratosphere, mesosphere, and ionosphere. As shown in this figure, the division is based on temperature inversions that occur at the higher altitudes; the altitudes of these inversions vary with the season and with the geographic latitude. Although the general shape of the curves remains the same for all latitudes, the altitudes of the inversions are higher over the equator and lower over the poles; the curves presented in Figure 10.3 refer to middle latitudes. The boundary areas at each temperature inversion are called tropopause, stratopause, and mesopause, respectively. Pollution of the atmosphere is generally the least appreciated of all environmental issues.
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Evans, John. "Water." In Elements of a Sustainable World, 235–72. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198827832.003.0006.
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The physical properties of water provide a framework for many day-to-day experiences: including the energy intrinsic to the melting and boiling of water, and in the increase in vapour density with temperature. The availability of freshwater is sequestered mainly in ice caps and groundwater and most readily acquired water emanates from the rainwater that falls on land. The demands of water for processing (Virtual water) are substantial. Extension fo water supply by desalination of seawater by reverse osmosis is explained. Options for extraction of minerals from seawater are also developed. The challenges posed by heavy elements, pharmaceuticals and plastics on wastewater treatment and drinking water supplies are elaborated
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"State-of-the-Art Materials for Adsorptive Heat Energy Conversion." In Technology Development for Adsorptive Heat Energy Converters, 1–24. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-4432-7.ch001.
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The chapter is focused on state of the art of materials for adsorptive heat energy conversion basic principles for substantiation of working pair choice. Types of heat storage materials based on heat storage mechanism were compared. Sensible heat mechanism of thermal energy is based on increasing the temperature of the material. Phase-change mechanism of heat energy storage concerns with alternating reversible processes of phase-changing. As a rule, they are mainly melting-crystallization. Thermo-chemical heat energy storage mechanism is based on reversible chemical reactions. Limitations of conventional sensible heat storage are shown to lowest density of heat energy storage determined by sensible heat of materials, which led to large mass storage units and additional needs of large areas and building volumes, calculated according to heat storage density, constant changing the temperature when discharged, the need for a large overheating of heat storage media. The main defects of phase-change materials are instability of properties of heat-accumulating substances in multiple cycles of crystallization – melting, degradation in time, corrosion activity, the need for developed surfaces of heat exchange and environmental danger. Commercilisation of thermal chemical storage materials is strongly limited by high operating temperatures of thermal chemical storage materials, which are unacceptable for systems of district heating and decentralized heat supply due to sanitary regulations, impropriety for multifold cycling because of irreversibility of a wide range of chemical reactions. Perspective of adsorptive heat energy storage and conversion is shown. Interval of operating temperatures and heat storage density of conventional adsorptive materials are shown to be intermediate between phase-change and thermal chemical heat storage materials. Properties of probable adsorptive heat storage materials were analysed according with literary data. Low adsorptive capacity of conventional adsorbents results in low heat of adsorption and heat energy storage density. Salts forming crystalline hydrate occur to exhibit rather high energy storage density of 1.9–2.7 GJ/m3 of crystalline hydrate, but their application is strongly inhibited not only by physical and chemical instability along with the corrosive activity of these salts at high temperatures, but instability in multifold cycling, degradation in time, and an underdeveloped heat exchange surface. As engineering solution, modification of conventional adsorbents with salt can be considered. Composites ‘salt inside porous matrix' is shown to be promising alternative to conventional adsorbents. Main advantages of these materials are low regeneration temperature and high adsorptive capacity. Crucial impediments of industrial introduction of composite adsorbents ‘salt inside porous matrix' is shown to be complex technology of their production based on rather expensive dry and wet impregnation of porous media by crystalline hydrate solutions. As an alternative, sol gel method for obtaining composite adsorbents ‘silica gel – crystalline hydrate' developed by authors is suggested. The adsorption properties of the obtained composite adsorbents ‘silica gel – sodium sulphate' and ‘silica gel – sodium acetate' are shown to be non-linear combinations of characteristics of silica gel and massive salt. The key distinction of kinetics of adsorption of water vapor with massive salts and composites obtained with sol gel method is shown to be difference limitative stage of process. The adsorption of water with massive crystalline hydrates is shown to be complicated by kinetic limitations. For composite adsorbents limiting stage is water transport through the pore system. Composites ‘slilica gel – crystalline hydrate' are shown to be a promising material for adsorptive heat energy storage and conversion.
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"Structure and Properties of Composite Adsorbents Salt Inside Porous Matrix." In Technology Development for Adsorptive Heat Energy Converters, 43–87. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-4432-7.ch003.
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The chapter is devoted to structure and properties of composite adsorbents ‘salt inside porous matrix'. Characteristics of adsorbents ‘salt inside porous matrix', such as ‘zeolite – crystalline hydrate', ‘vermiculite – crystalline hydrate', ‘silica gel – crystalline hydrate' were analysed. Main advantages of composite adsorbents are shown to be higher adsorptive capacity and lower regeneration temperature as compared with host matrix. Adsorptive capacities of composite materials are shown to be significantly enhanced by introduction of salts in host matrix such as zeolite, vermiculite, or silica gel. Water uptake by composite adsorbent is shown to be increased by rising the salt content in it. The drawback of most of existing impregnation technologies is shown to be impossibility of obtaining composite with salt content more than 40 – 60% along with complexity. Sol gel method is shown to be an alternative for conventional impregnation methods. Properties of adsorbents ‘silica gel – sodium sulphate' synthesized according to sol gel method developed by authors were considered. The composite ‘silica gel – sodium sulphate' composition and structure were studied by IR-spectroscopy and wide-angle x-ray scattering. Adsorptive properties of crystalline Na2SO4 when allocated in silicon oxygen matrix are shown to result from dispersion up to nanoscale. Adsorptive capacities and heat of adsorption of composites ‘silica gel – sodium sulphate' and ‘silica gel – sodium acetate' surpass almost by 30% the value calculated from the linear superposition of the sorption capacities of the sorbent and massive salt. Their adsorption properties are shown to be not a linear combination of properties of silica gel and salt. The formation of a unique structure promoting an increase in the rate of reaction between crystalline hydrates and water vapor in the developed pores of the silicon-oxygen matrix is confirmed. It leads to increasing the heat of adsorption and the heat energy storage density. Strong difference of water sorption kinetic curves of composite ‘silica gel – sodium sulphate' and massive sodium sulphate is revealed. The correlation of their composition, structure, water adsorption kinetic, and operating characteristic as heat storage material is stated.
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Oriakhi, Christopher O. "Liquids and Solids." In Chemistry in Quantitative Language. Oxford University Press, 2009. http://dx.doi.org/10.1093/oso/9780195367997.003.0016.
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The atoms or molecules in a liquid have enough kinetic energy to partially overcome the forces of attraction between them. Therefore, they are in constant random motion (as in a gas) but they are still relatively close together. However, they are not as tightly packed, or as well ordered, as in a solid. There is not as much free space in a liquid as in a gas. The atoms or molecules may aggregate together to form chains or rings that readily move relative to one another; this gives a liquid its fluid (flow) properties. Liquids generally occur as compounds. For example, water, ethanol, and carbon tetrachloride are liquids at room temperature. However, a few elements are also liquids at room temperature: bromine, cesium, gallium, mercury, and rubidium. A liquid is characterized by the following physical properties: boiling point and freezing point, density, compressibility, surface tension, and viscosity. These properties of a liquid are greatly influenced by the strength of its intermolecular forces. In summary: • Liquids have definite volume but no definite shape. They take on the shape of their containers. • Liquids are characterized by low compressibility, low rigidity, and high density relative to gases. • Liquids diffuse through other liquids. • Liquids can vaporize into the space above them and produce a vapor pressure. Polar molecules possess an electric dipole moment, μ, defined as the product of the magnitude of the partial charges Q+ and Q− on the molecule and the distance r separating the charges. In mathematical terms, it is given by the equation: μ = Qr The unit for μ is debyes (D), and 1 D = 3.336×10−30 coulomb meter (C-m). No interatomic bonds are completely ionic. Knowing the dipole moment of a compound, though, lets us differentiate ionic from covalent bonds by calculating the percent ionic character for the bonds. The percent ionic character of a bond is found by comparing the measured dipole moment of the molecule of the type A−B with the calculated dipole moment for the 100% ionized compound A+B−.
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Magee, Patrick, and Mark Tooley. "Solubility, Vaporisation and Vaporisers." In The Physics, Clinical Measurement and Equipment of Anaesthetic Practice for the FRCA. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199595150.003.0013.
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In discussing humidity in the preceding chapter, the concept of equilibrium between water and its vapour has been introduced as a thermodynamic concept. The concept of vaporisation of other liquids such as volatile anaesthetic agents follows on naturally from that, but first of all it will be worth taking a detour through a discussion on solubility of gases and vapours in their own and other liquids [Davis 2003]. To maintain simplicity in the discussion on humidity, no mention was made of the presence of air or other gas above the surface of the water, only the water vapour. Depending on the solubility of the gas in the liquid, a variable amount of the gas dissolves in the liquid, whether that be air in water or carbon dioxide in blood. As will be discussed in the section on vaporisation, some molecules of gas enter the liquid and some leave it, depending on their individual kinetic energies, until equilibrium is reached. If the pressure inside the container with the gas or vapour and liquid is increased, then the partial pressure of the gas above the liquid surface increases; this increases the population density of gas molecules, resulting in more of the gas molecules dissolving in the liquid. Henry’s Law states that for a fixed temperature the solubility of a gas in a liquid is proportional to its partial pressure in equilibrium with the liquid. Note the condition of constant temperature because, in addition, solubility decreases with increased temperature. This occurs because an increase in the thermal energy of the dissolved gas molecules increases the partial pressure of the gas and encourages it to come out of solution (see below on vaporisation). Thus gas bubbles are more apparent in liquids that are heated. A historical clinical example of the relevance of ambient pressure and nitrogen solubility in body tissues is in decompression sickness associated with tunnel workers. Modern examples include underwater diving and, to a lesser extent, aviators and space walking astronauts. Nitrogen is a compressible gas and goes into solution in body tissue spaces under compression if the miner, tunnel worker, or diver is breathing ambient air.
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Brock, Fred V., and Scott J. Richardson. "Upper Air Measurements." In Meteorological Measurement Systems. Oxford University Press, 2001. http://dx.doi.org/10.1093/oso/9780195134513.003.0014.
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Measurements of atmospheric properties become progressively more difficult with altitude above the surface of the earth, and even surface measurements are difficult over the oceans. First balloons, then airplanes and rockets, were used to carry instruments aloft to make in-situ measurements. Now remote sensors, both ground-based and satellite-borne, are used to monitor the atmosphere. In this context, upper air means all of the troposphere above the first hundred meters or so and, in some cases, the stratosphere. There are many uncertainties associated with remote sensing, so there is a demand for in-situ sensors to verify remote measurements. In addition, the balloon- borne instrument package is relatively inexpensive. However, it should be noted that cost is a matter of perspective; a satellite with its instrumentation, ground station, etc. may be cost-effective when the mission is to make measurements all over the world with good space and time resolution, as synoptic meteorology demands. Upper air measurements of pressure, temperature, water vapor, and winds can be made using in-situ instrument packages (carried aloft by balloons, rockets, or airplanes) and by remote sensors. Remote sensors can be classified as active (energy emitters like radar or lidar) or passive (receiving only, like microwave radiometers), and by whether they “look” up from the ground or down from a satellite. Remote sensors are surveyed briefly before discussing in-situ instruments. Profiles of temperature, humidity, density, etc. can be estimated from satellites using multiple narrow-band radiometers. These are passive sensors that measure longwave radiation upwelling from the atmosphere. For example, temperature profiles can be estimated from satellites by measuring infrared radiation emitted by CO2 (bands around 5000 μm) and O2 (bands around 3.4μm and 15μm) in the atmosphere. Winds can be estimated from cloud movements or by using the Doppler frequency shift due to some component of the atmosphere being carried along with the wind. An active sensor (radar) is used to estimate precipitation and, if it is a Doppler radar, determine winds. The great advantage of satellite-borne instruments is that they can cover the whole earth with excellent spatial resolution.
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Wu, Zhiyuan, and Mack Conde. "Response of the Coastal Ocean to Tropical Cyclones." In Current Topics in Tropical Cyclone Research. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.90620.
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The Northwest Pacific and the South China Sea region are the birthplaces of most monsoon disturbances and tropical cyclones and are an important channel for the generation and transmission of water vapor. The Northwest Pacific plays a major role in regulating interdecadal and long-term changes in climate. China experiences the largest number of typhoon landfalls and the most destructive power affected by typhoons in the world. The hidden dangers of typhoon disasters are accelerating with the acceleration of urbanization, the rapid development of economic construction and global warming. The coastal cities are the most dynamic and affluent areas of China’s economic development. They are the strong magnetic field that attracts international capital in China, and are also the most densely populated areas and important port groups in China. Although these regions are highly developed, they are vulnerable to disasters. When typhoons hit, the economic losses and casualties caused by gale, heavy rain and storm surges were particularly serious. This chapter reviews the response of coastal ocean to tropical cyclones, included sea surface temperature, sea surface salinity, storm surge simulation and extreme rainfall under the influence of tropical cyclones.
Conference papers on the topic "Water vapor density"
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Valtr, Pavel, Pavel Pechac, and Martin Grabner. "Water vapor density profile statistics in the atmospheric boundary layer." In 2017 11th European Conference on Antennas and Propagation (EUCAP). IEEE, 2017. http://dx.doi.org/10.23919/eucap.2017.7928173.
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Petrishchev, Vitaly, Zhiyao Yin, Caroline Winters, Walter R. Lempert, and Igor V. Adamovich. "Measurements of OH and H number density distributions in a near-surface discharge at the liquid water / water vapor interface." In 53rd AIAA Aerospace Sciences Meeting. Reston, Virginia: American Institute of Aeronautics and Astronautics, 2015. http://dx.doi.org/10.2514/6.2015-0934.
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Bosch-Lluis, X., H. Park, A. Camps, S. C. Reising, S. Sahoo, S. Padmanabhan, N. Rodriguez-Alvarez, I. Ramos-Perez, and E. Valencia. "A radiometer concept to retrieve the 3-D radiometric emission from atmospheric temperature and water vapor density." In IGARSS 2011 - 2011 IEEE International Geoscience and Remote Sensing Symposium. IEEE, 2011. http://dx.doi.org/10.1109/igarss.2011.6050170.
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Mao, Yijin, and Yuwen Zhang. "Molecular Simulation on Explosive Boiling of Water on a Hot Copper Plate." In ASME 2013 Heat Transfer Summer Conference collocated with the ASME 2013 7th International Conference on Energy Sustainability and the ASME 2013 11th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/ht2013-17001.
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In this paper, molecular dynamics simulation is carried out to study the explosive boiling of liquid water film heated by a hot copper plate in a confined space. A more physically-sound thermostat is applied to control the temperature of the metal plate and then to heat water molecules that are placed in the elastic wall confined simulation domain. The results show that liquid water molecules close to the plate are instantly overheated and undergo an explosive phase transition. A huge pressure in the region between liquid film and hot copper plate formed at the beginning and leads to a low density vapor region by partially vaporizing water film. A non-vaporization molecular layer, with a constant density of 0.2 g/cm3, tightly attached to the surface of the plate is observed. The z-component of COM (center of mass) trajectory of the liquid film in the confined space is tracked and analyzed. The one-dimensional density profile indicates the water film have a piston-like motion after short period of explosive boiling. Temperatures at three corresponding regions, which are vapor, liquid, and vapor from the top plate surface, are also computed and analyzed along with the piston-like motion of the bulk liquid film.
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Holden, Nathan, and Norbert Mu¨ller. "Optimal Wheel Diameter Design for a Water-Vapor (R-718), Axial, Compressor." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-14039.
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There is an interest to phase out environmentally harmful refrigerants (ie: HCFC-12, HCFC-22, but also HCFC-134A and other). Theoretical analysis coupled with mostly European research has proven that water-vapor (R-718) technology can be comparable to and even more efficient than other modern chiller technology using conventional refrigerants. The crucial component to succeed with water-vapor as refrigerant is the compressor. European compressor designs already introduced and commercialized have shown that with the currently available mechanics of using water-vapor, energy consumption can be reduced by as much as 20% over conventional technology utilizing refrigerants like HCFC134A. However, currently these compressor designs are physically large and the chillers can be as much as five (5) times more expensive to manufacture and install. Often for this reason they are often deemed to be insufficient. Much more reasonably priced compressors of possibly smaller size are desired now to developed water-vapor into an economically viable refrigerant, that may also be applicable for smaller cooling capacities. The presented work looks at the preliminary design considerations to determine the minimum impeller-wheel diameter with respect to the pre-determined operating parameters (ie: limiting relative critical Mach number, rotational speed, total fluid temperature, total fluid density, etc....). The results need then to be further refined in subsequent steps leading to a final design not discussed here. With the preliminary optimal impeller-wheel diameter of a water-vapor (R-718) compressor as established here, industry can easily perform a critical first step in developing a workable water-vapor (R-718) refrigeration system.
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Ma, H. K., and S. H. Huang. "Simulation of Water Vapor Transport Phenomena in Proton Exchange Membrane Fuel Cells (PEMFCs)." In ASME 2006 4th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2006. http://dx.doi.org/10.1115/fuelcell2006-97022.
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The objective of this paper is to study the influences of water vapor concentration in membrane and flow channels under the different operation conditions. The studied flow channels by CFDRC code include serpentine and interdigitated flow channels which have different gas transportation mechanisms. At the same time, the computer code, based upon Okada’s one dimensional model, was built to predict the influences of the electro-osmosis effect, the foreign impurity cations and the water balance time on water concentration in the membrane by Fortran 90. Both of interdigitated and serpentine flow fields show that water vapor accumulates near the cathode outlet of the membrane. And, the serpentine flow field accumulates more water vapor than interdigitated flow field does. As the inlet water mass fraction below 10%, the drying out problem may happen to reduce current density. In addition, the foreign impurity cations may induce the stronger electro-osmosis effect and reduce the effect of water back diffusion; hence, cause the accumulating of water in the cathode. It needs more water balance time and decreases the membrane performance.
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Tabasinejad, Farshad, Yalda Barzin, Robert Gordon Moore, Sudarshan A. Mehta, Kees Cornelius Van Fraassen, Jay Rushing, and Kent Edward Newsham. "Water/CO2 System At High Pressure And Temperature Conditions: Measurement And Modeling Of Density In Equilibrium Liquid And Vapor Phases." In SPE EUROPEC/EAGE Annual Conference and Exhibition. Society of Petroleum Engineers, 2010. http://dx.doi.org/10.2118/131636-ms.
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Bhatt, B. L. "Onset of Water Hammer Phenomenon Following Flow Surge Characteristics in Tube-Type Condensing Flows." In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45276.
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Two-Phase region, in condensing flow undergoing complete condensation inside a tube, acts as an amplifier of any small internal or external disturbances. A small, externally imposed change in the inlet vapor flow rate, or heat flux, leads to substantial surges in the outlet liquid flow rate, including the possibility of flow reversals. Also, if the conditions are right, slight internal disturbances as a result of vapor/liquid interaction, can lead to sustained oscillations of large amplitude, such as in the outlet liquid flow rate. Such surging characteristics coupled with rapid bubble collapse may lead to water hammer phenomenon. This paper will summarize both experimental observations and theoretical models as a result of externally imposed, or internally induced, flow changes in condensing flows. The physics of the processes, including liquid/vapor density ratio, vapor compressibility, bubble collapse, and liquid inertia will be highlighted. The condensing flow stability criterion will be used to provide a possible physical and an analytical basis for the catastrophic piping failure due to a condensation induced water hammer.
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Ma, W. M., Z. L. Yang, A. Giri, and B. R. Sehgal. "Numerical Simulation of Hydrodynamics of a Heavy Liquid Drop Covered by Vapor Film in a Water Pool." In 10th International Conference on Nuclear Engineering. ASMEDC, 2002. http://dx.doi.org/10.1115/icone10-22359.
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A numerical study on the hydrodynamics of a droplet covered by vapor film in water pool is carried out. Two level set functions are used as to implicitly capture the interfaces among three immiscible fluids (melt-drop, vapor and coolant). This approach leaves only one set of conservation equations for the three phases. A high-order Navier-Stokes solver, called Cubic-Interpolated Pseudo-Particle (CIP) algorithm, is employed in combination with level set approach, which allows large density ratios (up to 1000), surface tension and jump in viscosity. By this calculation, the hydrodynamic behavior of a melt droplet falling into a volatile coolant is simulated, which is of great significance to reveal the mechanismof steam explosion during a hypothetical severe reactor accident.
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Hays, Michael R., Hongbo Wang, and William S. Oates. "Force Characterization of Hygroscopic Liquid Crystal Elastomers." In ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2010. http://dx.doi.org/10.1115/smasis2010-3690.
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The actuation forces of a hydrophilic liquid crystal elastomer (LCE) in response to water vapor was tested and modeled. These materials exhibit asymmetric swelling as water vapor is absorbed into one side of the elastomer film. This gives rise to deflection away from the water source. Deformation due to water vapor has shown to be on the order of seconds and is reversible which provides unique sensing and actuation characteristics for elastomer films. The constitutive behavior is modeled by using nonlinear continuum mechanics to predict internal changes in density of the liquid crystal elastomer and subsequent deformation by correlating moisture exposure with changes in the elastomer’s density. In order to compare the model and obtain a set material parameters, a micro-Newton measuring device was designed and tested to quantify the forces generated in the liquid crystal elastomer under bending. Forces ranging between 1 to 8 μN were measured as a function of the location of the water vapor source. The results provide important insight into chemical force response and sensing for a number of biomedical and microfluidic applications.