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Journal articles on the topic 'Heat and mass balance'
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1
Sun, Weijun, Xiang Qin, Wentao Du, Weigang Liu, Yushuo Liu, Tong Zhang, Yuetong Xu, Qiudong Zhao, Jinkui Wu, and Jiawen Ren. "Ablation modeling and surface energy budget in the ablation zone of Laohugou glacier No. 12, western Qilian mountains, China." Annals of Glaciology 55, no. 66 (2014): 111–20. http://dx.doi.org/10.3189/2014aog66a902.
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AbstractGlacier surface melting can be described using energy-balance models. We conducted a surface energy budget experiment to quantify surface energy fluxes and to identify factors affecting glacial melt in the ablation zone of Laohugou glacier No. 12, western Qilian mountains. The surface energy budget was calculated based on data from an automatic weather station, and turbulent fluxes calculated using the bulk-aerodynamic approach were corrected using measurements from an eddy-covariance system. Simulated mass balances were validated by stake observations. Net shortwave radiation was the primary component of the surface energy balance (126Wm–2), followed by sensible heat flux. Net longwave radiation (–45Wm–2) and latent heat flux (–12.8 Wm–2) represented heat sinks. The bulk-aerodynamic method underestimated sensible and latent heat fluxes by 3.4 and 1.2 W m–2, respectively. The simulated total mass balance of –1703mmw.e. exceeded the observed total by 90 mm w.e. Daily positive accumulated temperature and low albedo were the main factors accelerating glacier melt. An uncertainty assessment showed that mass balance was very sensitive to albedo and varied by 36% when albedo changed by 0.1.
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Prowse, Terry D. "Heat and mass balance of an ablating ice jam." Canadian Journal of Civil Engineering 17, no. 4 (August 1, 1990): 629–35. http://dx.doi.org/10.1139/l90-071.
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This paper reports on the heat and mass balance of an ablating ice jam at the confluence of the Liard and Mackenzie rivers in the spring of 1983. From May 6 to May 9, sufficient data were collected to determine the magnitude and relative importance of the major heat fluxes that caused thermal decay of the ice jam. The total atmospheric heat input of 1.25 × 108 MJ and the much larger contribution from hydrothermal sources of 9.80 × 109 MJ resulted in a total melt of 3.24 × 107 m3 of ice within the jam. These data in combination with previous results regarding jam dimensions permitted calculation of ice jam porosity, a variable frequently used in hydraulic studies of river ice jams although unverified by field data. The largest potential error in the calculations was related to the accuracy of water temperature measurement. Accounting for this resulted in an estimate of porosity of 0.38 ± 10% which lends credence to the commonly assumed value of 0.40. Details of the field conditions, instrumentation, theoretical methods, and results of the energy and mass balance analyses are described. Key words: floating ice, ice breakup, ice jams, ice melt, ice porisity.
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Dunets, A. A., V. I. Klimok, and A. B. Polonsky. "Mass balance and heat transport in the equatorial Atlantic." Soviet Journal of Physical Oceanography 3, no. 1 (January 1992): 27–34. http://dx.doi.org/10.1007/bf02198490.
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Korycki, Ryszard. "Local Optimization of Bonnet Thickness in Global Heat Balance of Neonate." Fibres and Textiles in Eastern Europe 25 (February 28, 2017): 81–88. http://dx.doi.org/10.5604/12303666.1227886.
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Global heat transport for an neonate body is determined by means of heat balance with the term describing evaporation. The heat storage rate is the unbalanced difference between the metabolic heat production and various heat loss mechanisms within all body parts. The most sensitive portion is the head, which forces local optimization of the bonnet thickness. The local problem is described by differential heat and mass transport equations and the set of conditions. The changeable covering area of the bonnet can equalise the global heat balance and prevent hyperthermia or hypothermia.
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Wang, Puyu, Zhongqin Li, Christoph Schneider, Hongliang Li, Alexandra Hamm, Shuang Jin, Chunhai Xu, Huilin Li, Xiaoying Yue, and Min Yang. "A Test Study of an Energy and Mass Balance Model Application to a Site on Urumqi Glacier No. 1, Chinese Tian Shan." Water 12, no. 10 (October 15, 2020): 2865. http://dx.doi.org/10.3390/w12102865.
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In this study, energy and mass balance is quantified using an energy balance model to represent the glacier melt of Urumqi Glacier No. 1, Chinese Tian Shan. Based on data from an Automatic Weather Station (4025 m a.s.l) and the mass balance field survey data nearby on the East Branch of the glacier, the “COupled Snowpack and Ice surface energy and Mass balance model” (COSIMA) was used to derive energy and mass balance simulations during the ablation season of 2018. Results show that the modeled cumulative mass balance (−0.67 ± 0.03 m w.e.) agrees well with the in-situ measurements (−0.64 ± 0.16 m w.e.) (r2 = 0.96) with the relative difference within 5% during the study period. The correlation coefficient between modeled and observed surface temperatures is 0.88 for daily means. The main source of melt energy at the glacier surface is net shortwave radiation (84%) and sensible heat flux (16%). The energy expenditures are from net longwave radiation (55%), heat flux for snow/ice melting (32%), latent heat flux of sublimation and evaporation (7%), and subsurface heat flux (6%). The sensitivity testing of mass balance shows that mass balance is more sensitive to temperature increase and precipitation decrease than temperature decrease and precipitation increase.
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Shaltout, M., and A. Omstedt. "Calculating the water and heat balances of the Eastern Mediterranean basin using ocean modelling and available meteorological, hydrological, and ocean data." Ocean Science Discussions 8, no. 3 (June 14, 2011): 1301–38. http://dx.doi.org/10.5194/osd-8-1301-2011.
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Abstract. This paper analyses the Eastern Mediterranean water and heat balances over a 52-yr period. The modelling uses a process-oriented approach resolving the one-dimensional equations of momentum, heat, and salt conservation, with turbulence modelled using a two-equation model. The exchange through the Sicily Channel connecting the Eastern and Western basins is calculated from satellite altimeter data. The results illustrates that calculated surface temperature and salinity follow the reanalysed data well and with biases of −0.4 °C and −0.004, respectively. Monthly and yearly temperature and salinity cycles are also satisfactory simulated. Reanalysed data and calculated water mass structure and heat balance components are in good agreement, indicating that the air-sea interaction and the turbulent mixing are realistically simulated. The study illustrates that the water balance in the Eastern Mediterranean basin is controlled by the difference between inflows/outflows through the Sicily Channel and by the net precipitation rates. The heat balance is controlled by the heat loss from the water surface, sun radiation into the sea, and heat flow through the Sicily Channel, the first two displaying both climate trends. An annual net heat loss of approximately 9 W m−2 was balanced by net heat in flow through the Sicily Channel.
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Hochet, Antoine, Rémi Tailleux, Till Kuhlbrodt, and David Ferreira. "Global heat balance and heat uptake in potential temperature coordinates." Climate Dynamics 57, no. 7-8 (June 13, 2021): 2021–35. http://dx.doi.org/10.1007/s00382-021-05832-7.
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AbstractThe representation of ocean heat uptake in Simple Climate Models used for policy advice on climate change mitigation strategies is often based on variants of the one-dimensional Vertical Advection/Diffusion equation (VAD) for some averaged form of potential temperature. In such models, the effective advection and turbulent diffusion are usually tuned to emulate the behaviour of a given target climate model. However, because the statistical nature of such a “behavioural” calibration usually obscures the exact dependence of the effective diffusion and advection on the actual physical processes responsible for ocean heat uptake, it is difficult to understand its limitations and how to go about improving VADs. This paper proposes a physical calibration of the VAD that aims to provide explicit traceability of effective diffusion and advection to the processes responsible for ocean heat uptake. This construction relies on the coarse-graining of the full three-dimensional advection diffusion for potential temperature using potential temperature coordinates. The main advantage of this formulation is that the temporal evolution of the reference temperature profile is entirely due to the competition between effective diffusivity that is always positive definite, and the water mass transformation taking place at the surface, as in classical water mass analyses literature. These quantities are evaluated in numerical simulations of present day climate and global warming experiments. In this framework, the heat uptake in the global warming experiment is attributed to the increase of surface heat flux at low latitudes, its decrease at high latitudes and to the redistribution of heat toward cold temperatures made by diffusive flux.
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Zhang, Guoshuai, Shichang Kang, Koji Fujita, Eva Huintjes, Jianqing Xu, Takeshi Yamazaki, Shigenori Haginoya, et al. "Energy and mass balance of Zhadang glacier surface, central Tibetan Plateau." Journal of Glaciology 59, no. 213 (2013): 137–48. http://dx.doi.org/10.3189/2013jog12j152.
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AbstractClimate variables that control the annual cycle of the surface energy and mass balance on Zhadang glacier in the central Tibetan Plateau were examined over a 2 year period using a physically based energy-balance model forced by routine meteorological data. The modelled results agree with measured values of albedo, incoming longwave radiation, surface temperature and surface level of the glacier. For the whole observation period, the radiation component dominated (82%) the total surface energy heat fluxes. This was followed by turbulent sensible (10%) and latent heat (6%) fluxes. Subsurface heat flux represented a very minor proportion (2%) of the total heat flux. The sensitivity of specific mass balance was examined by perturbations of temperature (±1 K), relative humidity (±20%) and precipitation (±20%). The results indicate that the specific mass balance is more sensitive to changes in precipitation than to other variables. The main seasonal variations in the energy balance were in the two radiation components (net shortwave radiation and net longwave radiation) and these controlled whether surface melting occurred. A dramatic difference in summer mass balance between 2010 and 2011 indicates that the glacier surface mass balance was closely related to precipitation seasonality and form (proportion of snowfall and rainfall).
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Acharya, Anushilan, and Rijan Kayastha. "Mass and Energy Balance Estimation of Yala Glacier (2011–2017), Langtang Valley, Nepal." Water 11, no. 1 (December 20, 2018): 6. http://dx.doi.org/10.3390/w11010006.
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Six-year glaciological mass balance measurements, conducted at the Yala Glacier between November 2011 and November 2017 are presented and analyzed. A physically-based surface energy balance model is used to simulate summer mass and energy balance of the Yala Glacier for the 2012–2014 period. Cumulative mass balance of the Yala Glacier for the 2011–2017 period was negative at −4.88 m w.e. The mean annual glacier-wide mass balance was −0.81 ± 0.27 m w.e. with a standard deviation of ±0.48 m w.e. The modelled mass balance values agreed well with observations. Modelling showed that net radiation was the primary energy source for the melting of the glacier followed by sensible heat and heat conduction fluxes. Sensitivity of mass balance to changes in temperature, precipitation, relative humidity, surface albedo and snow density were examined. Mass balance was found to be most sensitive to changes in temperature and precipitation.
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Fujita, Koji, and Yutaka Ageta. "Effect of summer accumulation on glacier mass balance on the Tibetan Plateau revealed by mass-balance model." Journal of Glaciology 46, no. 153 (2000): 244–52. http://dx.doi.org/10.3189/172756500781832945.
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AbstractThe characteristics and sensitivities of a cold-based glacier on the Tibetan Plateau, where the summer monsoon provides most of the mass input to glaciers, are discussed using an energy-balance model incorporating the process of water refreezing. The model accurately represents the observational results related to the mass balance of Xiao Dongkemadi glacier on the central plateau during 1992/93. Our data revealed that the mass balance of cold glaciers cannot simply be described by the surface mass/heat balances, because about 20% of infiltrated water is refrozen and thus does not run off from the glacier. Model calculations demonstrate that glaciers in an arid environment can maintain their mass since the monsoon provides precipitation during the melting season. Snowfall in summer keeps surface albedo high and largely restrains ablation. Nevertheless, the calculations also make clear that glaciers on the plateau are more vulnerable than those of other regions because of summer accumulation. In the monsoon climate, warming would cause not only a decrease in accumulation, but also a drastic increase in ablation in combination with surface-albedo lowering. Therefore, although glaciers on and around the plateau can be sustained by summer accumulation, they are more vulnerable to warming than winter-accumulation-type glaciers.
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Liu, Xiangchun, Xin Su, Jinming Ma, Yuxiao Zhu, Xuzhen Zhu, and Hui Tian. "Information filtering based on eliminating redundant diffusion and compensating balance." International Journal of Modern Physics B 33, no. 13 (May 20, 2019): 1950129. http://dx.doi.org/10.1142/s0217979219501297.
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In statistical physics, researchers concentrate on mass diffusion and heat conduction-based information filtering models, which effectively facilitate recommendation accuracy and diversity. There are many improved methods combining mass diffusion with heat conduction theories. Research results show that the best results are achieved when the combination of mass diffusion and heat conduction reaches equilibrium. With elaborative analysis, we find that similarity redundancies derive from the attribute correlations of objects, and deduce the similarity estimation deviation. Considering the former deficiencies, we propose a novel model through eliminating redundant diffusion and compensating balance (shortly ERD-CB), which symmetrically combines mass diffusion with heat conduction process through balance compensation. Three benchmark datasets from Movielens, Amazon and Netflix are used in our extensive experiments. Experiment results show that the ERD-CB model outperforms the benchmarkbaselines for accuracy, diversity and novelty.
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Lozynskyi, Vasyl, Roman Dichkovskiy, Pavlo Saik, and Volodymyr Falshtynskyi. "Coal Seam Gasification in Faulting Zones (Heat and Mass Balance Study)." Solid State Phenomena 277 (June 2018): 66–79. http://dx.doi.org/10.4028/www.scientific.net/ssp.277.66.
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In this article, the mass and heat balance calculations of underground coal gasification process for thin coal seams in faulting zones of Lvivskyi coal basin (Ukraine) are defined. The purpose of the research is to establish regularities of heat and mass balance changes in faulting zones influence due to usage air and oxygen-enriched blast. A comprehensive methodology that included analytical calculations is implemented in the work. The output parameters of coal gasification products for the Lvivvyhillia coal mines are detailed. The heat balance is performed on the basis of the mass balance of underground coal gasification analytical results and is described in detail. Interpretations based on the conducted research and investigation are also presented. Conclusions regarding the implementation of the offered method are made on the basis of undertaken investigations. According to conducted research the technology of underground coal gasification can be carry out in the faulting zone of stable geodynamic and tectonic activity. The obtained results with sufficient accuracy in practical application will allow consume coal reserves in the faulting zones using environmentally friendly conversion technology to obtain power and chemical generator gas, chemicals and heat.
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Roemmich, Dean, John Gilson, Josh Willis, Philip Sutton, and Ken Ridgway. "Closing the Time-Varying Mass and Heat Budgets for Large Ocean Areas: The Tasman Box." Journal of Climate 18, no. 13 (July 1, 2005): 2330–43. http://dx.doi.org/10.1175/jcli3409.1.
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Abstract The role of oceanic advection in seasonal-to-interannual balances of mass and heat is studied using a 12-yr time series of quarterly eddy-resolving expendable bathythermograph (XBT) surveys around the perimeter of a region the authors call the Tasman Box in the southwestern Pacific. The region contains the South Pacific’s subtropical western boundary current system and associated strong mesoscale variability. Mean geostrophic transport in the warm upper ocean (temperature greater than 12°C) is about 3.8 Sv (1 Sv ≡ 106 m3 s−1) southward into the box across the Brisbane, Australia–Fiji northern edge. Net outflows are 3.3 Sv eastward across the Auckland, New Zealand–Fiji edge, and 2.7 Sv southward across Sydney, Australia–Wellington, New Zealand. Mean Ekman convergence of 2.2 Sv closes the mass budget. Net water mass conversions in the upper ocean consist of inflow of waters averaging about 26°C and 35.4 psu balanced by outflow at about 18°C and 35.7 psu, and reflect the net evaporation and heat loss in the formation of South Pacific Subtropical Mode Water. The mean heat balance shows good agreement between ocean heat flux convergence (42.3 W m−2), heat loss to the atmosphere from the NCEP–NCAR reanalysis (39.2 W m−2), and heat storage calculated from data in the box interior (1.3 W m−2). On interannual time scales, volume transport through the box ranges from about 1 to 9 Sv, with heat flux convergence ranging from about 20 to 60 W m−2. An interannual balance in the heat budget of the warm layer is achieved to within about 10 W m−2 (or 6 W m−2 for the upper 100 m alone). Maxima in the advective heat flux convergence occurred in 1993, 1997, and 1999–2000, and corresponded to maxima in air–sea heat loss. The evolution of surface-layer temperature in the region is the residual of nearly equal and opposing effects of ocean heat flux convergence and air–sea exchange. Hence, ocean circulation is a key element in the interannual heat budget of the air–sea climate system in the western boundary current region.
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Nakamura, Akifumi, Eiji Kiyonaga, Yukimasa Yamamura, Yoshihisa Shimizu, Tomoaki Minowa, Yoji Noda, and Yukihiko Matsumura. "Detailed Analysis of Heat and Mass Balance for Supercritical Water Gasification." JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 41, no. 8 (2008): 817–28. http://dx.doi.org/10.1252/jcej.07we321.
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Yeoh, G. H., and J. Y. Tu. "Population balance modelling for bubbly flows with heat and mass transfer." Chemical Engineering Science 59, no. 15 (August 2004): 3125–39. http://dx.doi.org/10.1016/j.ces.2004.04.023.
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Carvalho, J. A., and P. R. Gotaç. "Heat and mass balance analysis of an incinerator for aqueous wastes." International Communications in Heat and Mass Transfer 20, no. 4 (July 1993): 535–44. http://dx.doi.org/10.1016/0735-1933(93)90065-4.
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Krenke, A. N., and V. M. Menshutin. "Calculation of Mass Balance of Glaciers by Remote-Sensing Imagery Using Similarity of Accumulation and Ablation Isoline Patterns." Journal of Glaciology 33, no. 115 (1987): 363–68. http://dx.doi.org/10.1017/s0022143000008960.
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Abstract An investigation of the combined heat, ice, and water balances was carried out in the Marukh glacier basin (west Caucasus) in 1966–67 to 1976–77, according to the International Hydrological Decade programme. Averaged glacier mass balance for these 11 years appears to be −55 g cm−2 year−1 according to stake measurements, and −51 g cm−2 year−1 according to geodetic measurements. The variability of accumulation is estimated as C v = 0.15 and of ablation as C v = 0.11. Thus, the variation in accumulation governs the oscillations in glacier balance. The inner nourishment of the glacier was also taken into account. The glacier mass balance is closely related to the relation between the accumulation and ablation areas. The “transient” values of both figures during the whole period of ablation can be used for this relation. The forms of the accumulation and ablation fields are similar from year to year and from one 10 day period to another. The areas of the accumulation and ablation zones are very different from one year to another. On the contrary, the average specific balance for each zone changes very little. One can use these features for the construction of accumulation, ablation, and specific mass-balance maps from satellite imagery. Mean values for the mass-balance terms occur in the vicinity of the equilibrium line. They can be calculated by using the air temperatures. Deviations from the means in different areas of the glacier determine the typical fields of the mass-balance terms.
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Krenke, A. N., and V. M. Menshutin. "Calculation of Mass Balance of Glaciers by Remote-Sensing Imagery Using Similarity of Accumulation and Ablation Isoline Patterns." Journal of Glaciology 33, no. 115 (1987): 363–68. http://dx.doi.org/10.3189/s0022143000008960.
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AbstractAn investigation of the combined heat, ice, and water balances was carried out in the Marukh glacier basin (west Caucasus) in 1966–67 to 1976–77, according to the International Hydrological Decade programme. Averaged glacier mass balance for these 11 years appears to be −55 g cm−2 year−1 according to stake measurements, and −51 g cm−2 year−1 according to geodetic measurements. The variability of accumulation is estimated as Cv = 0.15 and of ablation as Cv = 0.11. Thus, the variation in accumulation governs the oscillations in glacier balance. The inner nourishment of the glacier was also taken into account. The glacier mass balance is closely related to the relation between the accumulation and ablation areas. The “transient” values of both figures during the whole period of ablation can be used for this relation. The forms of the accumulation and ablation fields are similar from year to year and from one 10 day period to another. The areas of the accumulation and ablation zones are very different from one year to another. On the contrary, the average specific balance for each zone changes very little. One can use these features for the construction of accumulation, ablation, and specific mass-balance maps from satellite imagery. Mean values for the mass-balance terms occur in the vicinity of the equilibrium line. They can be calculated by using the air temperatures. Deviations from the means in different areas of the glacier determine the typical fields of the mass-balance terms.
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Blynskaya, E. V., S. V. Tishkov, K. V. Alekseyev, and S. V. Minaev. "Mathematical models of the process of submlimationand optimization of lyophilization modes." Russian Journal of Biotherapy 17, no. 3 (November 25, 2018): 20–28. http://dx.doi.org/10.17650/1726-9784-2018-17-3-20-28.
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The purposeof this study is to analyze methods of mathematical modeling for calculating the stage of primary sublimation, as the most important stage in lyophilization technology. Presented are mathematical formulas, equations for the calculation of heat and mass transfer processes, during the removal of 90 % of all frozen ice. A model is considered that takes into account the contribution of all thermal effects, including the transient energy balance, taking into account the heat transfer through the side wall of the vial and radiation, even if they are present in a small amount. The mathematical model can be used to optimize the lyophilization cycle, and also as tools for technological monitoring (using sensors based on models). The model considered in the article is a one-dimensional nonstationary state model in which the correct comprehensive transient energy balance has been introduced to describe the heat transfer through the glass of the vial, and the results are estimated using experimental data. The equations used in the simulation describe the mass and energy balances in the dried layer, taking into account the rate of adsorption/desorption of water at the interface, mass and heat transfer at the sublimation interface, as well as the energy balance of heat transfer in the wall of vials, shelf and other factors affecting the process of sublimation. Conclusions are made on the presented mathematical models and the characteristic of the direction of the process of optimization of primary sublimation in lyophilization technology is given.
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Seltzer, Geoffrey O. "Climatic Interpretation of Alpine Snowline Variations on Millennial Time Scales." Quaternary Research 41, no. 2 (March 1994): 154–59. http://dx.doi.org/10.1006/qres.1994.1017.
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AbstractThe depression of snowlines, or equilibrium-line altitudes, of alpine glaciers is often used by glacial geologists to infer variations in mass balance. The climatic interpretation of snowline depression, however, is complicated by the number of factors that control glacier mass balance. The simple lapse-rate method of temperature interpretation ignores the effects of changes in radiation and snow accumulation. The statistical approach to temperature interpretation, which regresses precipitation and temperature against snowline altitude, neglects the effect of radiation. The most comprehensive approach for the climatic interpretation of snowline depression couples the heat and mass balances of a glacier surface. A sensitivity analysis that utilizes the coupled heat- and mass-balance approach indicates that the ∼1000-m variation in snowline of alpine glaciers on glacial-to-interglacial time scales could be a result of significant changes in temperature, and to a lesser extent changes in insolation. Snowline variations are sensitive only to relatively large changes in annual accumulation, which should also be evident in other proxy records of moisture change. The approaches outlined here provide glacial geologists with a summary of how various climatic forcings associated with glaciation may be quantified from snowline data.
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Zou, Hui Fen, Ying Chao Fei, and Min Yu. "Brief Analysis of the Heat and Mass Balance in Sludge Bio-Drying Process." Advanced Materials Research 518-523 (May 2012): 34–38. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.34.
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Bio-drying is an important method to reduce the excess sludge which use the inner biomass of sludge itself to generate heat for a water discharging has a broad prospects in sludge treatment. However, our research in this field is still very limited. In order to better mastering and promoting sludge bio-drying technology, this paper summarized the advantages of bio-drying, initially described the microbial mechanism of spontaneous heat generation and the heat and mass transfer phenomena in a bio-drying process, then build a macro heat conservation formula based on material conservation.
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Fialho, F. B., R. A. Bucklin, F. S. Zazueta, and R. O. Myer. "Theoretical model of heat balance in pigs." Animal Science 79, no. 1 (April 2004): 121–34. http://dx.doi.org/10.1017/s135772980005459x.
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AbstractA theoretical model was developed to predict the heat balance and body temperature of growing and finishing pigs subjected to different environments. The heat transfer modes considered in the model were convection to the surrounding air, conduction to the floor, long-wave radiation between the animal and the surrounding walls, shortwave radiation from the sun, evaporation on the skin surface, evaporation and heating of air in the respiratory tract and heating of ingested food and water. The heat balance is the net heat gain or loss from the environment due to all these processes, added to the animal's heat production. Body temperature is calculated over time using the heat balance, the animal's mass and the specific heat of the animal's body. Behavioural responses to heat and cold environments, such as vasoconstriction, vasodilatation, posture changes and huddling were expressed as changes in heat transfer coefficients and exposed surface area. The increase in evaporation under hot conditions was also considered. It was assumed that the animal's reaction to the environment may be expressed as a function of mean body temperature. The animal's heat production was considered an input to the model, which should reflect the increased metabolic rate in cold environments. Although further research is still needed to determine precisely some of the parameters, the model may be integrated with other models in order to compose a complete pig model.
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Mott, Rebecca, Andreas Wolf, Maximilian Kehl, Harald Kunstmann, Michael Warscher, and Thomas Grünewald. "Avalanches and micrometeorology driving mass and energy balance of the lowest perennial ice field of the Alps: a case study." Cryosphere 13, no. 4 (April 15, 2019): 1247–65. http://dx.doi.org/10.5194/tc-13-1247-2019.
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Abstract. The mass balance of very small glaciers is often governed by anomalous snow accumulation, winter precipitation being multiplied by snow redistribution processes (gravitationally or wind driven), or suppressed snow ablation driven by micrometeorological effects lowering net radiation and/or turbulent heat exchange. In this case study, we analysed the relative contribution of snow accumulation and ablation processes governing the long- and short-term mass balance of the lowest perennial ice field of the Alps, the Ice Chapel, located at 870 m a.s.l. in the Berchtesgaden National Park (Germany). This study emphasizes the importance of the local topographic setting for the survival of a perennial ice field located far below the climatic snow line. Although long-term mass balance measurements of the ice field surface showed a dramatic mass loss between 1973 and 2014, the ice field mass balance was rather stable between 2014 and 2017 and even showed a strong mass gain in 2017/2018 with an increase in surface height by 50 %–100 % relative to the ice field thickness. Measurements suggest that the winter mass balance clearly dominated the annual mass balance. At the Ice Chapel surface, 92 % of snow accumulation was gained by snow avalanching, thus clearly governing the 2017/2018 winter mass balance of the ice field with mean snow depths of 32 m at the end of the accumulation period. Avalanche deposition was amplified by preferential deposition of snowfall in the wind-sheltered rock face surrounding the ice field. Detailed micrometeorological measurements combined with a numerical analysis of the small-scale near-surface atmospheric flow field identified the micrometeorological processes driving the energy balance of the ice field. Measurements revealed a katabatic flow system draining down the ice field throughout the day, showing strong temporal and spatial dynamics. The spatial origin of the thermal flow system was shown to be of particular importance for the ice field surface energy balance. Numerical simulation indicates that deep katabatic flows, which developed at higher-elevation shaded areas of the rock face and drained down the ice field, enhance sensible heat exchange towards the ice field surface by enhancing turbulence close to the ice surface. Conversely, the shallow katabatic flow developing at the ice field surface appeared to laterally decouple the local near-surface atmosphere from the warmer adjacent air suppressing heat exchange. Numerical results thus suggest that shallow katabatic flows driven by the cooling effect of the ice field surface are especially efficient in lowering the climatic sensitivity of the ice field to the surrounding rising air temperatures. Such micrometeorological phenomena must be taken into account when calculating mass and energy balances of very small glaciers or perennial ice fields at elevations far below the climatic snow line.
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Hulth, John, Cecilie Rolstad, Karoline Trondsen, and Ragnhild Wedøe Rødby. "Surface mass and energy balance of Sørbreen, Jan Mayen, 2008." Annals of Glaciology 51, no. 55 (2010): 110–19. http://dx.doi.org/10.3189/172756410791392754.
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AbstractMass-balance measurements were initiated in 2007/08 on Sørbreen, Jan Mayen, including operation of automatic weather stations in the ablation zone. Mean daily melt rate is 3.6 cmw.e. d−1 for the investigated snow-free period of 115 days in June-September 2008. During this period, the net radiation is the largest contributor to melt. However, the relative contribution is highest in June (81%) and less in September (21%). The net longwave radiation is negative, acting as a heat sink. The climate on Jan Mayen is polar maritime with generally high humidity and overcast conditions. This leads to a positive latent heat flux, which represents condensation to the glacier surface. Persistent temperature inversions on the island lead to non-linear lapse rates and an ablation profile where melt does not necessarily decrease with increased elevation. A comparison of air temperatures on the glacier and twice-daily radiosonde ascents from the meteorological station, ∼ 20 km away from the glacier, shows that air temperatures at corresponding elevations are highly correlated (R2 = 0.94–0.96). This indicates that radiosonde temperature profiles can be valuable for determining lapse rates for melt modeling of the glacier.
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Oerlemans, J., and N. C. Hoogendoorn. "Mass-Balance Gradients and Climatic Change." Journal of Glaciology 35, no. 121 (1989): 399–405. http://dx.doi.org/10.1017/s0022143000009333.
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AbstractIt is generally assumed that the mass-balance gradient on glaciers is more or less conserved under climatic change. In studies of the dynamic response of glaciers to climatic change, one of the following assumptions is normally made: (i) the mass-balance perturbation is independent of altitude or (ii) the mass-balance profile does not change — it simply shifts up and down. Observational evidence for such an approach is not convincing; on some glaciers the inter-annual changes in mass balance seem to be independent of altitude, on others not at all. Moreover, it is questionable whether inter-annual variation can be “projected“ on different climatic states.To see what a physical approach might contribute, we developed an altitude-dependent mass-balance model. It is based on the energy balance of the ice/snow surface, where precipitation is included in a parameterized form and numerical integrations are done through an entire balance year (with a 30 min time step). Atmospheric temperature, snowfall, and atmospheric transmissivity for solar radiation are all dependent on altitude, so a mass-balance profile can be calculated. Slope and exposure of the ice/snow surface are taken into account (and the effects of these parameters studied). In general, the calculations were done for 100m elevation intervals.Climatological data from the Sonnblick Observatory (Austria; 3106 m a.s.l.) and from Vent (2000 m a.s.l.; Oetztal Alps, Austria) served as input for a number of runs. Simulation of the mass-balance profiles for Hinterseisferner (north-easterly exposure) and Kesselwandferner (south-easterly exposure) yields reasonable results. The larger balance gradient on Kesselwandferner is produced by the model, so exposure appears to be an important factor here.Sensitivity of mass-balance profiles to shading effects, different slope, and exposure are systematically studied. Another section deals with the sensitivity to climatic change. Perturbations of air temperature, cloudiness, albedo, and precipitation are imposed to see their effects on the mass-balance profiles. The results clearly show that, in general, mass-balance perturbations depend strongly on altitude. They generally increase down-glacier, and are not always symmetric about the reference state.For typical climatic conditions in the Alps, we found that a 1 K temperature change leads to a change in equilibrium-line altitude of 130 m. Three factors contribute to this large value; turbulent heat flux, longwave radiation from the atmosphere, and fraction of precipitation falling as snow. Here, the albedo feed-back increases the sensitivity in a significant way.
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Oerlemans, J., and N. C. Hoogendoorn. "Mass-Balance Gradients and Climatic Change." Journal of Glaciology 35, no. 121 (1989): 399–405. http://dx.doi.org/10.3189/s0022143000009333.
Full textAbstract:
AbstractIt is generally assumed that the mass-balance gradient on glaciers is more or less conserved under climatic change. In studies of the dynamic response of glaciers to climatic change, one of the following assumptions is normally made: (i) the mass-balance perturbation is independent of altitude or (ii) the mass-balance profile does not change — it simply shifts up and down. Observational evidence for such an approach is not convincing; on some glaciers the inter-annual changes in mass balance seem to be independent of altitude, on others not at all. Moreover, it is questionable whether inter-annual variation can be “projected“ on different climatic states.To see what a physical approach might contribute, we developed an altitude-dependent mass-balance model. It is based on the energy balance of the ice/snow surface, where precipitation is included in a parameterized form and numerical integrations are done through an entire balance year (with a 30 min time step). Atmospheric temperature, snowfall, and atmospheric transmissivity for solar radiation are all dependent on altitude, so a mass-balance profile can be calculated. Slope and exposure of the ice/snow surface are taken into account (and the effects of these parameters studied). In general, the calculations were done for 100m elevation intervals.Climatological data from the Sonnblick Observatory (Austria; 3106 m a.s.l.) and from Vent (2000 m a.s.l.; Oetztal Alps, Austria) served as input for a number of runs. Simulation of the mass-balance profiles for Hinterseisferner (north-easterly exposure) and Kesselwandferner (south-easterly exposure) yields reasonable results. The larger balance gradient on Kesselwandferner is produced by the model, so exposure appears to be an important factor here.Sensitivity of mass-balance profiles to shading effects, different slope, and exposure are systematically studied. Another section deals with the sensitivity to climatic change. Perturbations of air temperature, cloudiness, albedo, and precipitation are imposed to see their effects on the mass-balance profiles. The results clearly show that, in general, mass-balance perturbations depend strongly on altitude. They generally increase down-glacier, and are not always symmetric about the reference state.For typical climatic conditions in the Alps, we found that a 1 K temperature change leads to a change in equilibrium-line altitude of 130 m. Three factors contribute to this large value; turbulent heat flux, longwave radiation from the atmosphere, and fraction of precipitation falling as snow. Here, the albedo feed-back increases the sensitivity in a significant way.
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Azam, M. F., P. Wagnon, C. Vincent, AL Ramanathan, A. Mandal, and J. G. Pottakkal. "Processes governing the mass balance of Chhota Shigri Glacier (Western Himalaya, India) assessed by point-scale surface energy balance measurements." Cryosphere Discussions 8, no. 3 (June 5, 2014): 2867–922. http://dx.doi.org/10.5194/tcd-8-2867-2014.
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Abstract. Recent studies revealed that Himalayan glaciers have been shrinking at an accelerated rate since the beginning of the 21st century. However the climatic causes for this shrinkage remain unclear given that surface energy balance studies are almost nonexistent in this region. In this study, a point-scale surface energy balance analysis was performed using in-situ meteorological data from the ablation zone of Chhota Shigri Glacier over two separate periods (August 2012 to February 2013 and July to October 2013) in order to understand the response of mass balance to climate change. Energy balance numerical modeling provides quantification of the surface energy fluxes and identification of the factors affecting glacier mass balance. The computed ablation was validated by stake observations. During summer-monsoon period, net radiation was the primary component of the surface energy balance with 82% of the total heat flux which was complimented with turbulent sensible and latent heat fluxes with a share of 13% and 5%, respectively. A striking feature of energy balance is the positive turbulent latent heat flux, thus condensation or re-sublimation of moist air at the glacier surface takes place, during summer-monsoon period which is characterized by relatively high air temperature, high relative humidity and almost permanent melting surface. The impact of Indian summer monsoon on Chhota Shigri Glacier mass balance has also been assessed. This analysis demonstrates that the intensity of snowfall events during the summer-monsoon season plays a key role on surface albedo, in turn on melting, and thus is among the most important drivers controlling the annual mass balance of the glacier. Summer-monsoon air temperature, controlling the precipitation phase (rain vs. snow and thus albedo), counts, indirectly, also among the most important drivers for the glacier mass balance.
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Wang, Hongze, Motoki Nakanishi, and Yosuke Kawahito. "Dynamic balance of heat and mass in high power density laser welding." Optics Express 26, no. 5 (March 2, 2018): 6392. http://dx.doi.org/10.1364/oe.26.006392.
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Sugaya, H. "A snowpack evolution model based on the mass and heat balance method." Journal of Agricultural Meteorology 48, no. 5 (1993): 651–54. http://dx.doi.org/10.2480/agrmet.48.651.
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Moreno Azócar, Débora Lina, Marcelo Fabián Bonino, María Gabriela Perotti, James A. Schulte, Cristian Simón Abdala, and Félix Benjamín Cruz. "Effect of body mass and melanism on heat balance inLiolaemuslizards of thegoetschiclade." Journal of Experimental Biology 219, no. 8 (February 19, 2016): 1162–71. http://dx.doi.org/10.1242/jeb.129007.
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Li, Shi, Yan Hu, and Xi Ju Zong. "The Feasibility Research of Using an Intensified Continuous Mini-Reactor to Replace a Discontinuous Reactor." Advanced Materials Research 391-392 (December 2011): 894–99. http://dx.doi.org/10.4028/www.scientific.net/amr.391-392.894.
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An intensified continuous mini-reactor is introduced, to replace traditional discontinuous reactor, using in three-phase catalytic slurry hydrogenation. Under high pressure intensification, continuous mini-reactor behaves excellent performances of mass transfer and heat transfer, and presents the advantages of smaller volume, faster reaction rates, higher conversion and no solvent addition. The steady-state mathematic model is established, and the characteristic times of mass transfer and heat transfer are analyzed based on mass balance and energy balance Eq.s, the results can efficiently help the reactor design and optimization.
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Huang, Wenfeng, Bin Cheng, Jinrong Zhang, Zheng Zhang, Timo Vihma, Zhijun Li, and Fujun Niu. "Modeling experiments on seasonal lake ice mass and energy balance in the Qinghai–Tibet Plateau: a case study." Hydrology and Earth System Sciences 23, no. 4 (April 30, 2019): 2173–86. http://dx.doi.org/10.5194/hess-23-2173-2019.
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Abstract. The lake-rich Qinghai–Tibet Plateau (QTP) has significant impacts on regional and global water cycles and monsoon systems through heat and water vapor exchange. The lake–atmosphere interactions have been quantified over open-water periods, yet little is known about the lake ice thermodynamics and heat and mass balance during the ice-covered season due to a lack of field data. In this study, a high-resolution thermodynamic ice model was applied in experiments of lake ice evolution and energy balance of a shallow lake in the QTP. Basal growth and melt dominated the seasonal evolution of lake ice, but surface sublimation was also crucial for ice loss, accounting for up to 40 % of the maximum ice thickness. Sublimation was also responsible for 41 % of the lake water loss during the ice-covered period. Simulation results matched the observations well with respect to ice mass balance components, ice thickness, and ice temperature. Strong solar radiation, negative air temperature, low air moisture, and prevailing strong winds were the major driving forces controlling the seasonal ice mass balance. The energy balance was estimated at the ice surface and bottom, and within the ice interior and under-ice water. Particularly, almost all heat fluxes showed significant diurnal variations including incoming, absorbed, and penetrated solar radiation, long-wave radiation, turbulent air–ice heat fluxes, and basal ice–water heat fluxes. The calculated ice surface temperature indicated that the atmospheric boundary layer stratification was consistently stable or neutral throughout the ice-covered period. The turbulent air–ice heat fluxes and the net heat gain by the lake were much lower than those during the open-water period.
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Basu, Rahul. "Effect of Boundary Conditions on Phase Change in Rectilinear and Spherical Porous Media." Applied Mechanics and Materials 852 (September 2016): 625–31. http://dx.doi.org/10.4028/www.scientific.net/amm.852.625.
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This paper examines a model for coupled heat and mass transfer for freezing in a porous matrix with Dirichlet and convective boundary conditions. Variables include porosity, heat transfer coefficients, thermal and mass diffusivity, density, latent heat and boundary temperatures. It is shown that heat and mass transfer balance at the interface can affect stability. The effect of boundary conditions on the velocity of freezing is computed for some cases, and applications to physical problems highlighted
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Azam, M. F., P. Wagnon, C. Vincent, AL Ramanathan, V. Favier, A. Mandal, and J. G. Pottakkal. "Processes governing the mass balance of Chhota Shigri Glacier (western Himalaya, India) assessed by point-scale surface energy balance measurements." Cryosphere 8, no. 6 (November 27, 2014): 2195–217. http://dx.doi.org/10.5194/tc-8-2195-2014.
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Abstract. Some recent studies revealed that Himalayan glaciers were shrinking at an accelerated rate since the beginning of the 21st century. However, the climatic causes for this shrinkage remain unclear given that surface energy balance studies are almost nonexistent in this region. In this study, a point-scale surface energy balance analysis was performed using in situ meteorological data from the ablation zone of Chhota Shigri Glacier over two separate periods (August 2012 to February 2013 and July to October 2013) in order to understand the response of mass balance to climatic variables. Energy balance numerical modelling provides quantification of the surface energy fluxes and identification of the factors affecting glacier mass balance. The model was validated by comparing the computed and observed ablation and surface temperature data. During the summer-monsoon period, net radiation was the primary component of the surface energy balance accounting for 80 % of the total heat flux followed by turbulent sensible (13%), latent (5%) and conductive (2%) heat fluxes. A striking feature of the energy balance is the positive turbulent latent heat flux, suggesting re-sublimation of moist air at the glacier surface, during the summer-monsoon characterized by relatively high air temperature, high relative humidity and a continual melting surface. The impact of the Indian Summer Monsoon on Chhota Shigri Glacier mass balance has also been assessed. This analysis demonstrates that the intensity of snowfall events during the summer-monsoon plays a key role on surface albedo (melting is reduced in the case of strong snowfalls covering the glacier area), and thus is among the most important drivers controlling the annual mass balance of the glacier. The summer-monsoon air temperature, controlling the precipitation phase (rain versus snow and thus albedo), counts, indirectly, also among the most important drivers.
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Medica-Viola, Vedran, Sandi Baressi Šegota, Vedran Mrzljak, and Daniel Štifanić. "Comparison of conventional and heat balance based energy analyses of steam turbine." Pomorstvo 34, no. 1 (June 30, 2020): 74–85. http://dx.doi.org/10.31217/p.34.1.9.
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This paper presents a comparison of conventional and heat balance based energy analyses of steam turbine. Both analyses are compared by using measured operating parameters from low power steam turbine exploitation. The major disadvantage of conventional steam turbine energy analysis is that extracted energy flow streams are not equal in real (polytropic) and ideal (isentropic) expansion processes, while the heat balance based energy analysis successfully resolved mentioned problem. Heat balance based energy analysis require an increase of steam mass flow rates extracted from the turbine in ideal (isentropic) expansion process to ensure always the same energy flow streams to all steam consumers. Increase in steam mass flow rate extracted through each turbine extraction (heat balance based energy analysis) result with a decrease in energy power losses and with an increase in energy efficiency of whole turbine and all of its cylinders (when compared to conventional analysis). All of the obtained conclusions in this research are valid not only for the analyzed low power steam turbine, but also for any other steam turbine with steam extractions.
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Jóhannesson, Tómas, Bolli Pálmason, Árni Hjartarson, Alexander H. Jarosch, Eyjólfur Magnússon, Joaquín M. C. Belart, and Magnús Tumi Gudmundsson. "Non-surface mass balance of glaciers in Iceland." Journal of Glaciology 66, no. 258 (June 2, 2020): 685–97. http://dx.doi.org/10.1017/jog.2020.37.
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AbstractNon-surface mass balance is non-negligible for glaciers in Iceland. Several Icelandic glaciers are in the neo-volcanic zone where a combination of geothermal activity, volcanic eruptions and geothermal heat flux much higher than the global average lead to basal melting close to 150 mm w.e. a−1 for the Mýrdalsjökull ice cap and 75 mm w.e. a−1 for the largest ice cap, Vatnajökull. Energy dissipation in the flow of water and ice is also rather large for the high-precipitation, temperate glaciers of Iceland resulting in internal and basal melting of 20–150 mm w.e. a−1. The total non-surface melting of glaciers in Iceland in 1995–2019 was 45–375 mm w.e. a−1 on average for the main ice caps, and was largest for Mýrdalsjökull, the south side of Vatnajökull and Eyjafjallajökull. Geothermal melting, volcanic eruptions and the energy dissipation in the flow of water and ice, as well as calving, all contribute, and thus these components should be considered in mass-balance studies. For comparison, the average mass balance of glaciers in Iceland since 1995 is −500 to −1500 mm w.e. a−1. The non-surface mass balance corresponds to a total runoff contribution of 2.1 km3 a−1 of water from Iceland.
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Monde, M. "Analytical Study of Critical Heat Flux in Two-Phase Thermosyphon: Relationship Between Maximum Falling Liquid Rate and Critical Heat Flux." Journal of Heat Transfer 118, no. 2 (May 1, 1996): 422–28. http://dx.doi.org/10.1115/1.2825861.
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An analytical study has been done on the critical heat flux of a two-phase thermosyphon, in which a liquid film and a vapor flow exist in a countercurrent annular flow. The CHF point on the thermosyphon is proved to correspond to a maximum falling liquid rate fed to the thermosyphon, which can be determined from three equations of momentum, its partial derivative with void fraction, and mass balance in the thermosyphon. This maximum point, furthermore, becomes identical to the point at which an envelope line generated from the momentum equation and its partial derivative intersects the mass balance line. The CHF calculated from the maximum liquid rate is found to be in fairly good agreement with the existing CHF data.
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Vala, Jiří, and Petra Jarošová. "Identification of Effective Material Characteristics in Semilinear Equations of Heat and Mass Transfer." Advanced Materials Research 1126 (October 2015): 174–80. http://dx.doi.org/10.4028/www.scientific.net/amr.1126.174.
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Utilization of advanced materials in civil engineering motivates research in both experimental and computational methods of reliable identification of their material characteristics, as e.g. the thermal conductivity and diffusivity in semilinear evolutionary equations of heat conduction, coming from the energy balance in classical thermodynamics, or the capillary transfer coefficient in similar equations, coming from the mass balance. The paper presents mathematical preliminaries of such inverse analysis and an overview of computational approaches with references to practical applications.
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Ahlborn, Boye, and Robert W. Blake. "Why birds cannot be smaller than bees." Canadian Journal of Zoology 79, no. 9 (September 1, 2001): 1724–26. http://dx.doi.org/10.1139/z01-117.
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Birds and mammals of body mass M that live in cold climates cannot have a body radius, Rmin, below about 2.5 cm. This criterion follows from the balance of metabolic heat production described by Kleiber's function, Γ = 3.6M0.73, and heat-conduction losses through the body insulation. Rmin differs from the critical radius calculated from a heat-flow balance at the outer edge of the organism that does not consider metabolic limitations.
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Ohol, Sandeep, Mathew VK, Savita Shinde, and G. Balachandran. "Heat balance analysis in electric arc furnace for process improvement." E3S Web of Conferences 170 (2020): 02012. http://dx.doi.org/10.1051/e3sconf/202017002012.
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The current study deals with optimizing the melting process used in electric arc furnace by heat balance equations. Heat balance is a very important aspect in an arc furnace in which the energy input consists of electrical energy [65%], chemical energy [25%] and exothermic reaction heat [10%]. This energy is optimized with the charge mix, charge quantity, fluxes, fuel used, and O2 used in the burners. The present model considers all these aspects and gives heat distribution in the process. The model spreadsheet gives a reasonable prediction in terms of metal yield, composition, and energy consumption. The model also predicts the amount of iron oxidized in the process. The mass and heat balance model is a useful tool for process analysis and improves the process efficiency of electric arc furnace steelmaking.
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Dong, Jing Lan, Wei Ping Yan, and Chao Hui Zhang. "Convective Condensation of Oxy-Coal Combustion Flue Gas of Laminar Fow in a Vertical Pipe." Applied Mechanics and Materials 325-326 (June 2013): 389–97. http://dx.doi.org/10.4028/www.scientific.net/amm.325-326.389.
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The problem of the oxy-fuel combustion flue gas condensation is the condensation of vapor in the presence of high concentration non-condensable gas. The vapor condensing at dew point temperature releases heat and diffuses on to the surface of the pipe through a non-condensable gas film. Thus it is treated as combined heat and mass transfer problem governed by mass, momentum and energy balance equations for the vaporgas mixture and diffusion equation for the vapor species. The flow of the falling condensate film is governed by the momentum and energy balance equations. The temperature at the gas-to-liquid interface, at which the condensation takes place, is estimated with the help of the heat balance and mass balance equations at the interface. The local values of the condensation Nusselt number, condensate Reynolds number, gasliquid interface temperature and pressure drop are estimated from the numerical results for different values of the system parameters at inlet, such as vapor component, temperature of vaporgas mixture, gas phase Reynolds number and total pressure. The thermodynamic calculations were made and analyzed using numerical calculation method under different conditions.
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Linhardt, Tobias, Joseph S. Levy, and Christoph K. Thomas. "Water tracks intensify surface energy and mass exchange in the Antarctic McMurdo Dry Valleys." Cryosphere 13, no. 8 (August 19, 2019): 2203–19. http://dx.doi.org/10.5194/tc-13-2203-2019.
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Abstract. The hydrologic cycle in the Antarctic McMurdo Dry Valleys (MDV) is mainly controlled by surface energy balance. Water tracks are channel-shaped high-moisture zones in the active layer of permafrost soils and are important solute and water pathways in the MDV. We evaluated the hypothesis that water tracks alter the surface energy balance in this dry, cold, and ice-sheet-free environment during summer warming and may therefore be an increasingly important hydrologic feature in the MDV in the face of landscape response to climate change. The surface energy balance was measured for one water track and two off-track reference locations in Taylor Valley over 26 d of the Antarctic summer of 2012–2013. Turbulent atmospheric fluxes of sensible heat and evaporation were observed using the eddy-covariance method in combination with flux footprint modeling, which was the first application of this technique in the MDV. Soil heat fluxes were analyzed by measuring the heat storage change in the thawed layer and approximating soil heat flux at ice table depth by surface energy balance residuals. For both water track and reference locations over 50 % of net radiation was transferred to sensible heat exchange, about 30 % to melting of the seasonally thawed layer, and the remainder to evaporation. The net energy flux in the thawed layer was zero. For the water track location, evaporation was increased by a factor of 3.0 relative to the reference locations, ground heat fluxes by 1.4, and net radiation by 1.1, while sensible heat fluxes were reduced down to 0.7. Expecting a positive snow and ground ice melt response to climate change in the MDV, we entertained a realistic climate change response scenario in which a doubling of the land cover fraction of water tracks increases the evaporation from soil surfaces in lower Taylor Valley in summer by 6 % to 0.36 mm d−1. Possible climate change pathways leading to this change in landscape are discussed. Considering our results, an expansion of water track area would make new soil habitats accessible, alter soil habitat suitability, and possibly increase biological activity in the MDV. In summary, we show that the surface energy balance of water tracks distinctly differs from that of the dominant dry soils in polar deserts. With an expected increase in area covered by water tracks, our findings have implications for hydrology and soil ecosystems across terrestrial Antarctica.
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Li, Ke-jiang, Jian-liang Zhang, Zheng-jian Liu, Rui Mao, and Tian-jun Yang. "Comprehensive Evaluation of OxyCup Process for Steelmaking Dust Treatment Based on Calculation of Mass Balance and Heat Balance." Journal of Iron and Steel Research International 21, no. 6 (June 2014): 575–82. http://dx.doi.org/10.1016/s1006-706x(14)60089-3.
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TAKAHASHI, Toru, Eiichi KODA, and Yoshinobu NAKAO. "E209 Development of the performance deterioration diagnosis method to thermal power plant based on heat and mass balance analysis(Power System-2)." Proceedings of the International Conference on Power Engineering (ICOPE) 2009.2 (2009): _2–407_—_2–410_. http://dx.doi.org/10.1299/jsmeicope.2009.2._2-407_.
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Lu, Peng, Xiaowei Cao, Guoyu Li, Wenfeng Huang, Matti Leppäranta, Lauri Arvola, Jussi Huotari, and Zhijun Li. "Mass and Heat Balance of a Lake Ice Cover in the Central Asian Arid Climate Zone." Water 12, no. 10 (October 16, 2020): 2888. http://dx.doi.org/10.3390/w12102888.
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To improve the understanding of the seasonal evolution of the mass and heat budget of ice-covered lakes in the cold and arid climate zone, in-situ observations were collected during two winters (2016–2017 and 2017–2018) in Lake Wuliangsuhai, Inner Mongolia, China. The mean snow thickness was 5.2 and 1.6 cm in these winters, due to low winter precipitation. The mean ice thickness was 50.9 and 36.1 cm, and the ice growth rate was 3.6 and 2.1 mm day−1 at the lower boundary of ice. Analyses of mass and heat balance data from two winters revealed that the surface heat budget was governed by solar radiation and terrestrial radiation. The net heat flux loss of the ice was 9–22 W m−2, affected by the snow and ice thickness. Compared to boreal lakes, Lake Wuliangsuhai received more solar radiation and heat flux from the water. The ice temperature had a strong diurnal variation, which was produced by the diurnal cycles of solar radiation, and air and water temperatures. These results expand our knowledge of the evolution of mass and heat balance in temperate lakes of mid-latitude arid areas.
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Krepper, Eckhard, Matthias Beyer, Dirk Lucas, and Martin Schmidtke. "A population balance approach considering heat and mass transfer—Experiments and CFD simulations." Nuclear Engineering and Design 241, no. 8 (August 2011): 2889–97. http://dx.doi.org/10.1016/j.nucengdes.2011.05.003.
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Hatem, M. H., K. M. Abdelbary, and K. M. Morsy. "INVESTIGATE STEADY-STATE HEAT AND MASS BALANCE FOR GREENHOUSES PAD-FAN COOLING SYSTEM." Misr Journal of Agricultural Engineering 25, no. 4 (October 1, 2008): 1410–37. http://dx.doi.org/10.21608/mjae.2008.190276.
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Arpalahti, Antti, and Mari Lundström. "Water Balance of a Boreal Black Schist Heap Leach Operation." Mine Water and the Environment 39, no. 4 (May 29, 2020): 758–68. http://dx.doi.org/10.1007/s10230-020-00694-7.
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Abstract The current study presents the effect of process chemistry as well as climate conditions on the water balance of a heap leach operation for black-schist ore. The research is based on the actual water balance at the Terrafame (former Talvivaara) mine site in Finland during the years 2017 and 2018 (base case). In addition, scenarios with a deviation in climatic conditions (Antofagasta case), chemistry (non-heat generation case) and effects of climate change (RCP4.5 (representative concentration pathway) case and RCP8.5 case) were investigated. In the first case, the annual precipitation and evaporation were simulated for a highly arid climate such as in the Antofagasta Mountains, whereas in the second case, an assumption was made of no excess heat generation (exothermic reactions) in the heap reactions. The base case predicted a requirement of 9,000,000 m3 annual discharge of water from the site with the heaviest annual rainfall. The discharge requirement and therefore the water footprint of the plant was shown to be highly dependent on the climatic conditions, as the Antofagasta case predicted a discharge of water from the site as low as zero. Heat generation, typical of the reactions dominating in a boreal black-schist heap leach operation, was shown to be vital for water management operations and therefore discharge management in Nordic climatic conditions (the non-heat generation case), where the discharge requirement was shown to be nearly threefold compared to the base case (2018). If the black-schist ore body resided in Antofagasta, the freshwater consumption would be over eight times the current consumption in the base case in Finland. Climate change scenarios show that the changing climate would increase the range of variation but only increase the need for water discharge from the site by 5% in the wettest years, while raw water utilization would increase by 46 to 83% during the driest years. In general, the results highlight the issues related to the mass and energy balance of a heap leach nickel process, and therefore feasibility—showing that although the heat generation is ore- and process-specific, the water consumption as well as discharge to the surrounding environment is highly dependent on the climatic conditions (precipitation, temperature) in the geographical location.
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SEKI, Hirakazu, and Tomoaki KOMORI. "Mass, Energy and Exergy Balances for Heat Recovery Operation from Compost. Part 2. Validity of Microscopic Balance Equations." Environment Control in Biology 31, no. 4 (1993): 205–15. http://dx.doi.org/10.2525/ecb1963.31.205.
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Kitaytseva, Elena. "A new approach to the mathematical model of thermal energy balance." E3S Web of Conferences 97 (2019): 01028. http://dx.doi.org/10.1051/e3sconf/20199701028.
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Formation of balance of thermal energy and the heat carrier for a thermal network is carried out for the purpose of increase of efficiency of work of the heat supplying organization. The standard approach proposes to write off the difference between the released and realized heat energy for heat losses. The article proposes a new approach to the formation of the balance of thermal energy and coolant. It includes statistical analysis of telemetry data relating to the released thermal energy. Heat consumption was estimated by contractual load for heating, ventilation and hot water supply. In the mathematical model of the thermal balance for each term weight coefficients were introduced. To obtain the numerical values of these coefficients, the method of least squares was used. The results of checking the adequacy of mathematical models that take into account or neglect thermal losses are presented. The obtained coefficients for the mathematical model of heat balance were used for the mathematical model of mass balance. The results can be used to predict the cost of production and transmission of heat energy and coolant, to assess the efficiency of the heat network and the formation of tariff applications for the future.