Relevant bibliographies by topics / Mass exchange of land

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Mass exchange of land'

Author: Grafiati
Published: 28 June 2021
Last updated: 1 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Mass exchange of land.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Mass exchange of land"

1

Bugaіenko, Olena. "THE LAND REALLOCATION MODEL IN THE COURSE OF AGRICULTURAL LAND CONSOLIDATION IN UKRAINE." Geodesy and cartography 44, no. 3 (October 16, 2018): 106–12. http://dx.doi.org/10.3846/gac.2018.2049.

Full text
Abstract:
The issue of the effectiveness of agricultural land consolidation in the environment of land relations being reshaped, with Ukraine as the example has been scrutinized in the research. Land reallocation as the key constituent of land consolidation has been considered according to the existing approaches. Necessity for substantiation of the peerness of land plots to be reallocated has been singled out. Key factors influencing the peer agricultural land exchange in the process of reallocation have been defined. It is offered to define the peerness of agricultural land plots by a set of qualitative and spatial and technological characteristics. The improvement of the existing approaches to land reallocation by limiting for the reallocated land plots peerness by the preset characteristics has been suggested. The gist of the modelling is the minimization of distance from land plot to the farmhouse. Technical data characterizing the qualitative and spatial and technological characteristics of land plots at the reallotment have been defined. The assessment of the provided reallocation model with the example of the agricultural land mass has been provided. Land reallocation is accomplished by the voluntary land plot exchange. The analysis of the reallocation results using the provided model has been executed.
APA, Harvard, Vancouver, ISO, and other styles
2

Packet, W., and J. P. De Greve. "Who is Who in Algol-Land ? - Part II -." International Astronomical Union Colloquium 107 (1989): 339. http://dx.doi.org/10.1017/s0252921100087972.

Full text
Abstract:
AbstractIn part I (De Greve and Packet) we have investigated the occurrence of reversed phases of mass-transfer during Case A evolution in close binaries. If the initial period of a system is shorter than 1 - 2 days (Early Case A) the reversed phase starts before core hydrogen exhaustion of the gainer (part I). This type of evolution is characterized by at least two phases of slow mass-transfer.We have computed the evolution of four Early Case A systems with initial masses of the loser equal to 3 Mo and 5 Mo. These four systems start mass-exchange when Xc of the primary has decreased to 0.525 (75% of its initial value). They all experience two phases of slow mass-transfer.We find that both phases have about the same duration for all systems. The mass ratios are clearly distinct, being closer to unity during the first phase. In the Hertzsprung-Russell, mass-radius and mass-luminosity diagrams both components remain close to the main-sequence band during slow mass-transfer. Evolution as an Algol is ended when both components overflow their outer critical surface after a second reversal of the mass-transfer.Observed Algol systems evolving in Early Case A are scarce. A search thruogh the catalogue by Giuricin et al. gives us the following candidates: X Tri, SX Aur and V Pup. Based on their mass ratios, SX Aur can tentatively be assigned to the first phase of slow mass transfer and X Tri to the second phase. For V Pup (which is more massive) this choice can not be made with certainty.
APA, Harvard, Vancouver, ISO, and other styles
3

Adhikari, Surendra, Erik R. Ivins, Eric Larour, Lambert Caron, and Helene Seroussi. "A kinematic formalism for tracking ice–ocean mass exchange on the Earth's surface and estimating sea-level change." Cryosphere 14, no. 9 (September 2, 2020): 2819–33. http://dx.doi.org/10.5194/tc-14-2819-2020.

Full text
Abstract:
Abstract. Polar ice sheets are important components of the Earth system. As the geometries of land, ocean and ice sheets evolve, they must be consistently captured within the lexicon of geodesy. Understanding the interplay between the processes such as ice-sheet dynamics, solid-Earth deformation, and sea-level adjustment requires both geodetically consistent and mass-conserving descriptions of evolving land and ocean domains, grounded ice sheets and floating ice shelves, and their respective interfaces. Here we present mathematical descriptions of a generic level set that can be used to track both the grounding lines and coastlines, in light of ice–ocean mass exchange and complex feedbacks from the solid Earth and sea level. We next present a unified method to accurately compute the sea-level contribution of evolving ice sheets based on the change in ice thickness, bedrock elevation and mean sea level caused by any geophysical processes. Our formalism can be applied to arbitrary geometries and at all timescales. While it can be used for applications with modeling, observations and the combination of two, it is best suited for Earth system models, comprising ice sheets, solid Earth and sea level, that seek to conserve mass.
APA, Harvard, Vancouver, ISO, and other styles
4

Kleidon, A., M. Renner, and P. Porada. "Estimates of the climatological land surface energy and water balance derived from maximum convective power." Hydrology and Earth System Sciences 18, no. 6 (June 17, 2014): 2201–18. http://dx.doi.org/10.5194/hess-18-2201-2014.

Full text
Abstract:
Abstract. The land surface energy and water balances are tightly coupled by the partitioning of absorbed solar radiation into terrestrial radiation and the turbulent fluxes of sensible and latent heat, as well as the partitioning of precipitation into evaporation and runoff. Evaporation forms the critical link between these two balances. Its rate is strongly affected by turbulent exchange as it provides the means to efficiently exchange moisture between the heated, moist surface and the cooled, dry atmosphere. Here, we use the constraint that this mass exchange operates at the thermodynamic limit of maximum power to derive analytical expressions for the partitioning of the surface energy and water balances on land. We use satellite-derived forcing of absorbed solar radiation, surface temperature and precipitation to derive simple spatial estimates for the annual mean fluxes of sensible and latent heat and evaluate these estimates with the ERA-Interim reanalysis data set and observations of the discharge of large river basins. Given the extremely simple approach, we find that our estimates explain the climatic mean variations in net radiation, evaporation, and river discharge reasonably well. We conclude that our analytical, minimum approach provides adequate first order estimates of the surface energy and water balance on land and that the thermodynamic limit of maximum power provides a useful closure assumption to constrain the energy partitioning at the land surface.
APA, Harvard, Vancouver, ISO, and other styles
5

Kleidon, A., M. Renner, and P. Porada. "Estimates of the climatological land surface energy and water balance derived from maximum convective power." Hydrology and Earth System Sciences Discussions 11, no. 1 (January 8, 2014): 265–306. http://dx.doi.org/10.5194/hessd-11-265-2014.

Full text
Abstract:
Abstract. The land surface energy- and water balances are tightly coupled by the partitioning of absorbed solar radiation into terrestrial radiation and the turbulent fluxes of sensible and latent heat, as well as the partitioning of precipitation into evaporation and runoff. Evaporation forms the critical link between these two balances. Its rate is strongly affected by turbulent exchange as it provides the means to efficiently exchange moisture between the heated, moist surface and the cooled, dry atmosphere. Here, we use the constraint that this mass exchange operates at the thermodynamic limit of maximum power to derive analytical expressions for the partitioning of the surface energy- and water balances on land. We use satellite-derived forcing of absorbed solar radiation, surface temperature and precipitation to derive simple spatial estimates for the annual mean fluxes of sensible and latent heat and evaluate these estimates with the ERA-Interim reanalysis dataset and observations of the discharge of large river basins. Given the extremely simple approach, we find that our estimates explain the climatic mean variations in net radiation, evaporation, and river discharge reasonably well. We conclude that our analytical, minimum approach provides adequate first order estimates of the surface energy- and water balance on land and that the thermodynamic limit of maximum power provides a useful closure assumption to constrain the energy partitioning at the land surface.
APA, Harvard, Vancouver, ISO, and other styles
6

Medeiros, Brian, Alex Hall, and Bjorn Stevens. "What Controls the Mean Depth of the PBL?" Journal of Climate 18, no. 16 (August 15, 2005): 3157–72. http://dx.doi.org/10.1175/jcli3417.1.

Full text
Abstract:
Abstract The depth of the planetary boundary layer (PBL) is a climatologically important quantity that has received little attention on regional to global scales. Here a 10-yr climatology of PBL depth from the University of California, Los Angeles (UCLA) atmospheric GCM is analyzed using the PBL mass budget. Based on the dominant physical processes, several PBL regimes are identified. These regimes tend to exhibit large-scale geographic organization. Locally generated buoyancy fluxes and static stability control PBL depth nearly everywhere, though convective mass flux has a large influence at tropical marine locations. Virtually all geographical variability in PBL depth can be linearly related to these quantities. While dry convective boundary layers dominate over land, stratocumulus-topped boundary layers are most common over ocean. This division of regimes leads to a dramatic land–sea contrast in PBL depth. Diurnal effects keep mean PBL depth over land shallow despite large daytime surface fluxes. The contrast arises because the large daily exchange of heat and mass between the PBL and free atmosphere over land is not present over the ocean, where mixing is accomplished by turbulent entrainment. Consistent treatment of remnant air from the deep, daytime PBL is necessary for proper representation of this diurnal behavior over land. Many locations exhibit seasonal shifts in PBL regime related to changes in PBL clouds. These shifts are controlled by seasonal variations in buoyancy flux and static stability.
APA, Harvard, Vancouver, ISO, and other styles
7

Shin, Bum Shick, and Kyu Han Kim. "Environmental Assessments for Wetlands and Estuaries Management near Tidal Power Plant Using of Mass Balance Simulation." Applied Mechanics and Materials 672-674 (October 2014): 453–58. http://dx.doi.org/10.4028/www.scientific.net/amm.672-674.453.

Full text
Abstract:
The closed bay formed by a tidal power plant on the west coast of Korea has caused water quality to change due to nutrient increase and salinity alternation. The nutrients of the inner bay are often kept a balance with the aid of the outflow at the mouth of the bay. Hence it is necessary to minimize the environmental effects by forecasting the potential environmental changes caused by a tidal power construction. Seasonal observations of mass balance in the inner and outer Garolim Bay were performed. The low quality nutrients released from sediments, land and river were more dominant than the nutrients released from the outer bay in the study area. It was observed that the tidal power plant construction made water exchange ratio 57%.Various mitigation strategies such as water gates were studied so that the water exchange rate can be reduced. The change in the water exchange ratio is significantly reduced as the cross-section and the number of water gates is increased. The water exchange ratio was decreased by 8%, which increased nutrients in the inner bay. Results of numerical the nutrients decreased with the 7% increase in the inflow while the decrease in outflow discharges. However, it is considered only 0.2% increase in the entire mass balance of Garolim Bay relatively inadequate to mitigate the environmental impact.
APA, Harvard, Vancouver, ISO, and other styles
8

Sun, Yibo, Junyong Ma, Bilige Sude, Xingwen Lin, Haolu Shang, Bing Geng, Zhaoyan Diao, Jiaqiang Du, and Zhanjun Quan. "A UAV-Based Eddy Covariance System for Measurement of Mass and Energy Exchange of the Ecosystem: Preliminary Results." Sensors 21, no. 2 (January 8, 2021): 403. http://dx.doi.org/10.3390/s21020403.

Full text
Abstract:
Airborne eddy covariance (EC) measurement is one of the most effective methods to directly measure the surface mass and energy fluxes at the regional scale. It offers the possibility to bridge the scale gap between local- and global-scale measurements by ground-based sites and remote-sensing instrumentations, and to validate the surface fluxes estimated by satellite products or process-based models. In this study, we developed an unmanned aerial vehicle (UAV)-based EC system that can be operated to measure the turbulent fluxes in carbon dioxides, momentum, latent and sensible heat, as well as net radiation and photosynthetically active radiation. Flight tests of the developed UAV-based EC system over land were conducted in October 2020 in Inner Mongolia, China. The in-flight calibration was firstly conducted to correct the mounting error. Then, three flight comparison tests were performed, and we compared the measurement with those from a ground tower. The results, along with power spectral comparison and consideration of the differing measurement strategies indicate that the system can resolve the turbulent fluxes in the encountered measurement condition. Lastly, the challenges of the UAV-based EC method were discussed, and potential improvements with further development were explored. The results of this paper reveal the considerable potential of the UAV-based EC method for land surface process studies.
APA, Harvard, Vancouver, ISO, and other styles
9

Sun, Yibo, Junyong Ma, Bilige Sude, Xingwen Lin, Haolu Shang, Bing Geng, Zhaoyan Diao, Jiaqiang Du, and Zhanjun Quan. "A UAV-Based Eddy Covariance System for Measurement of Mass and Energy Exchange of the Ecosystem: Preliminary Results." Sensors 21, no. 2 (January 8, 2021): 403. http://dx.doi.org/10.3390/s21020403.

Full text
Abstract:
Airborne eddy covariance (EC) measurement is one of the most effective methods to directly measure the surface mass and energy fluxes at the regional scale. It offers the possibility to bridge the scale gap between local- and global-scale measurements by ground-based sites and remote-sensing instrumentations, and to validate the surface fluxes estimated by satellite products or process-based models. In this study, we developed an unmanned aerial vehicle (UAV)-based EC system that can be operated to measure the turbulent fluxes in carbon dioxides, momentum, latent and sensible heat, as well as net radiation and photosynthetically active radiation. Flight tests of the developed UAV-based EC system over land were conducted in October 2020 in Inner Mongolia, China. The in-flight calibration was firstly conducted to correct the mounting error. Then, three flight comparison tests were performed, and we compared the measurement with those from a ground tower. The results, along with power spectral comparison and consideration of the differing measurement strategies indicate that the system can resolve the turbulent fluxes in the encountered measurement condition. Lastly, the challenges of the UAV-based EC method were discussed, and potential improvements with further development were explored. The results of this paper reveal the considerable potential of the UAV-based EC method for land surface process studies.
APA, Harvard, Vancouver, ISO, and other styles
10

Tennyson, Robert. "From Unanimity to Proportionality: Assent Standards and the Parliamentary Enclosure Movement." Law and History Review 31, no. 1 (February 2013): 199–231. http://dx.doi.org/10.1017/s073824801200017x.

Full text
Abstract:
“Enclosure” has long been shorthand for describing the exchange of scattered strips of land and common rights for cohesive plots in premodern and modern England. Proprietors who farmed long strips of land throughout a village or released cattle on unused waste would receive at enclosure regular plots commensurate in value with earlier interests. The process of enclosure in a village could be gradual, as it predominantly was for much of the premodern period. Alternatively, as increasingly occurred in the modern era, the proprietors could enclose their lands in concert. Figure 1, two maps of Helmdon in Northamptonshire, depicts the vast change in holdings that could occur through enclosure.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Mass exchange of land"

1

Carrillo, Rojas Galo José [Verfasser], and Jörg [Akademischer Betreuer] Bendix. "On the multi-scale analysis of land-surface mass and energy exchanges for the tropical Andean páramo of Southern Ecuador / Galo José Carrillo Rojas ; Betreuer: Jörg Bendix." Marburg : Philipps-Universität Marburg, 2019. http://d-nb.info/1199537454/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Franco, Pietro Escobar. "Remoção de metais pesados utilizando resina Amberlite IR-120 em sistema batelada." Universidade Estadual do Oeste do Paraná, 2011. http://tede.unioeste.br:8080/tede/handle/tede/2924.

Full text
Abstract:
Submitted by Marilene Donadel (marilene.donadel@unioeste.br) on 2017-08-23T20:19:47Z No. of bitstreams: 1 Pietro E Franco 2011.pdf: 990760 bytes, checksum: fee1787afa670f26170e23dc070a0075 (MD5)
Made available in DSpace on 2017-08-23T20:19:47Z (GMT). No. of bitstreams: 1 Pietro E Franco 2011.pdf: 990760 bytes, checksum: fee1787afa670f26170e23dc070a0075 (MD5) Previous issue date: 2011-02-07
This study evaluated the removal of heavy metal íons Zn+2 and Ni+2 through the íon exchange process using a cationic resin Amberlite IR-120/Na+. The characterization of wastewater from an industry of electroplating was performed and the results were the basis for obtaining the aqueous solution used at work. Experiments were performed in batch system for the valuation of ion exchange kinetics of the binary systems Ni+2–Na+, Zn+2–Na+ and the ternary system Ni+2–Zn+2–Na+ in the initial concentrations of 20ppm and 200ppm, in the conditions of pH 4.5, agitation speed of 150rpm and 25ºC. Two models were tested to obtain kinetic parameters of ion exchange. In the simulation of kinetic model in which the ion exchange reaction was considered the limiting step during the model does not fit the experimental data. A second simulation, where the diffusion in the resin (linear driving force model) was assumed to be limiting step had better fit and evidence for the hypothesis that the experimental conditions the ion exchange process presents diffusional limitations. The value of mass transfer coefficients in the resin (ks) varied from 0.0032 to 0.043min-1. Kinetic studies showed that equilibrium is reached around 400 minutes for the systems with initial concentration of 20ppm and 60 minutes for systems with initial concentration of 200ppm. Experiments to obtain data of ion exchange equilibrium were performed for the binary systems Ni+2–Na+, Zn+2–Na+ and for the ternary system Ni+2–Zn+2–Na+ at concentrations of 160ppm and 300ppm (pH 4.5, agitation speed of 150rpm and 25ºC). The isotherms were modeled using the law of mass action ideal and not ideal. The Bromley and Wilson models were used to calculate the activity coefficient in solution and resin. Simulations were conducted for determining the value of the constant and equilibrium thermodynamics of the interaction parameters of Wilson. The results showed that the law of mass action is not ideal fits well the experimental data of binary systems. The simulation of the ternary equilibrium system was accomplished using a predictive, based on the interaction parameters of Wilson and equilibrium constants provided by the modeling of binary systems. The data predicted by the model were compared with experimental data and the results showed that the model was able to predict the behavior of the ternary system. The affinity of the studied ions with Amberlite IR-120 showed the following order: Zn+2 Ni+2 > Na+. For all experiments conducted in this study, the variation of pH and stoichiometry during the experiments were evaluated. For the parameter pH, speciation graphics were done using the HYDRA software and the results show that ions of interest in the solutions (Zn+2 and Ni+2) were above 95%. The average deviation from stoichiometry was less than 8%.
O presente trabalho avaliou a remoção dos íons de metais pesados Zn+2 e Ni+2 através do processo de troca iônica utilizando a resina catiônica Amberlite IR-120/Na+. A caracterização do efluente de uma indústria do ramo de galvanoplastia foi realizada e os resultados obtidos serviram de base para a obtenção da solução aquosa utilizada no trabalho. Experimentos foram realizados em sistema batelada para a avaliação da cinética de troca iônica dos sistemas binários Ni+2–Na+, Zn+2–Na+ e para o sistema ternário Ni+2–Zn+2–Na+ nas concentrações iniciais de 20ppm e 200ppm, nas condições de pH de 4.5, velocidade de agitação de 150rpm e temperatura de 25ºC. Dois modelos foram testados para obtenção de parâmetros de cinética de troca iônica. Na simulação do modelo cinético em que a reação de troca iônica foi considerada a etapa limitante o modelo não se ajustou aos dados experimentais. Uma segunda simulação, em que a difusão na resina (modelo da força motriz linear) foi assumida como etapa limitante apresentou melhor ajuste e evidencia a hipótese de que para as condições experimentais adotadas o processo de troca iônica apresenta limitações difusionais. O valor dos coeficientes de transferência de massa na resina (ks) apresentaram valores entre 0,0032-0,043min-1. Estudos cinéticos mostraram que o equilíbrio é atingido em torno de 400 minutos para os sistemas com concentração inicial de 20ppm e de 60 minutos para os sistemas com concentração inicial de 200ppm. Experimentos para obtenção de dados de equilíbrio de troca iônica foram realizados para os sistemas binários Ni+2–Na+, Zn+2–Na+ e para o sistema ternário Ni+2–Zn+2–Na+ nas concentrações de 160ppm e 300ppm (pH de 4.5, velocidade de agitação de 150rpm e temperatura de 25ºC). As isotermas foram modeladas com uso da lei da ação das massas ideal e não ideal. Os modelos de Bromley e Wilson foram utilizados para o cálculo do coeficiente de atividade na solução e na resina. Realizou-se simulação para a determinação do valor da constante termodinâmica de equilíbrio e dos parâmetros de interação de Wilson. Os resultados mostraram que a lei da ação das massas não ideal se ajustou bem aos dados experimentais dos sistemas binários. A simulação do sistema de equilíbrio ternário foi realizada de forma preditiva, baseada nos parâmetros de interação de Wilson e constantes de equilíbrio fornecidas pelas modelagens dos sistemas binários. Os dados preditos pelo modelo foram comparados com os dados experimentais e os resultados mostraram que o modelo foi capaz de prever o comportamento do sistema ternário. A afinidade dos íons estudados com a resina Amberlite IR-120 mostrou a seguinte ordem: Zn+2 Ni+2 > Na+. Para todos os experimentos realizados neste trabalho, a variação de pH e de estequiometria ao longo dos experimentos foram avaliados. Para o parâmetro pH, gráficos de especiação foram realizados com o uso do software HYDRA e os resultados mostram que os íons de interesse nas soluções (Zn+2 e Ni+2) estavam acima de 95%. O desvio médio da estequiometria não foi superior a 8%.
APA, Harvard, Vancouver, ISO, and other styles
3

Carrera, Marco. "Significant events of interhemispheric atmospheric mass exchange." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=38162.

Full text
Abstract:
The various modes of atmospheric mass redistribution characterize the principal variations of the general circulation of the atmosphere. Interhemispheric exchanges of atmospheric mass occur with considerable regularity on intraseasonal time-scales. Observational evidence from previous studies indicates that anomalous and persistent regional atmospheric mass distributions (e.g., atmospheric blocking) may often be related to interhemispheric atmospheric mass exchange.
Using the National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) reanalysis, we identify significant events when the northern hemisphere (NH) loses dry atmospheric mass on subseasonal time-scales during the boreal winter from 1968 to 1997. A total of 25 events is found, with a preferred time-scale of 9 days. The linear correlation coefficient between the dry atmospheric mass anomalies for the NH and southern hemisphere (SH) is -0.91 for the 25 significant events, indicating very strong interhemispheric compensation and increasing our confidence in the suitability of this dataset for the study of interhemispheric dry atmospheric mass exchange.
Positive sea-level pressure anomalies are found over northern Eurasia, the North Pacific and the North Atlantic prior to the onset of the composite NH dry atmospheric mass collapse event. Over northern Eurasia the positive atmospheric mass anomaly associated with the building of the Siberian high is found to be a statistically significant precursor to the events. The breakdown of NH dry atmospheric mass occurs in association with the decay of the positive atmospheric mass anomaly in the North Pacific as a cyclone deepens explosively in the Gulf of Alaska. Pressure surges over Southeast Asia and North America, associated with statistically significant positive atmospheric mass anomalies, are mechanisms that act to channel the atmospheric mass equatorward on a rapid time-scale (~4 days). The dry atmospheric mass increase in the SH is manifested as enhanced surface ridging over the South Pacific and South Indian Oceans.
Preferential interhemispheric interaction is found in the region between 100°E and 130°E, and over the central Pacific in the vicinity of the dateline. A prominent channel of southeastward dry atmospheric mass flux, emanating from the Australian continent, combined with a southward channel from the equatorial central Pacific, contribute to the atmospheric mass buildup over the South Pacific.
The role of a Southeast Asian pressure surge was examined for a representative event. A large evacuation of atmospheric mass from northern Eurasia occurs as the atmospheric mass surges equatorward and into the SH. Along the west coast of Australia, a southerly pressure surge extends equatorward and converges with the northerly surge to create a pronounced near equatorial zonal pressure gradient. A low-level westerly wind burst develops in response to this enhanced zonal pressure gradient as part of the onset of an active phase of the Australian summer monsoon. We show that three prominent anticyclonic circulations intensify in the southern hemisphere extratropics, stretching from the South Indian Ocean to the South Pacific, beneath regions of upper tropospheric dry atmospheric mass convergence, originating from the monsoon convection outflow. These anticyclonic circulations are largely responsible for the dry atmospheric mass increase in the SH.
APA, Harvard, Vancouver, ISO, and other styles
4

Msiza, Andrew Khutso. "Hybrid synthesis method for mass exchange networks." Master's thesis, University of Cape Town, 2001. http://hdl.handle.net/11427/5434.

Full text
Abstract:
Bibliography: leaves 121-[123].
Process synthesis can be approached from three techniques: heuristics, physical and thermodynamic insight, and mathematical programming. Hybrid methods where two or all of the synthesis methods are combined are now becoming used, taking advantage of the combined strength of the individual techniques. In this thesis the option of combining pinch analysis (a physical and thermodynamic insight-based approach) and superstructure-based programming is explored.
APA, Harvard, Vancouver, ISO, and other styles
5

Hinshaw, Jesse C. "Let's exchange the experience." Atlanta, Ga. : Georgia State University, 2009. http://digitalarchive.gsu.edu/art_design_theses/42/.

Full text
Abstract:
Thesis (M.F.A.)--Georgia State University, 2009.
Title from title page (Digital Archive@GSU, viewed July 12, 2010) Cheryl Goldsleger, committee chair; Joe Peragine, Matthew Sugarman, committee members. Includes bibliographical references (p. 22).
APA, Harvard, Vancouver, ISO, and other styles
6

Gustafsson, David. "Land surface heat exchange over snow and frozen soil." Licentiate thesis, KTH, Land and Water Resources Engineering, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1231.

Full text
Abstract:

The energy exchange in the soil-snow-vegetation-atmospheresystem was studied to improve the quantitative knowledge of thegoverning processes. The lack of such knowledge contributes tothe uncertainty in the applicability of many existing modelsindependent of the temporal or spatial scale. The theoreticalbackground and available methods for measurements and numericalsimulations were reviewed. Numerical simulation models andavailable data sets representing open land and boreal forestwere evaluated in both diurnal and seasonal time-scales.Surface heat fluxes, snow depth, soil temperatures andmeteorological conditions were measured at an agriculturalfield in central Sweden over two winters, 1997-1999. Twoone-dimensional simulation models of different complexity wereused to simulate the heat and water transfer in thesoil-snow-atmosphere system and compared with the measurements.Comparison of simulated and observed heat fluxes showed thatparameter values governing the upper boundary condition weremore important than the formulation of the internal mass andheat balance of the snow cover. The models were useful toevaluate the lack of energy balance closure in the observedsurface heat fluxes, which underlined the importance ofimproved accuracy in eddy correlation measurements of latentflow during winter conditions.

The representation of boreal forest in the land surfacescheme used within a weather forecast model was tested with athree-year data set from the NOPEX forest site in centralSweden. The formulation with separate energy balances forvegetation and the soil/snow beneath tree cover improvedsimulation of the seasonal and diurnal variations of latent andsensible heat flux compared with an older model version.Further improvements of simulated surface heat fluxes could beexpected if the variation of vegetation properties within andbetween years and a new formulation of the boundary conditionsfor heat flux into the soil is included.

Keywords: Surface energy balance, Snow, Boreal forest,SVAT models, Eddy-correlation Measurements, Latent heat flux,Sensible heat flux, Net radiation, Soil temperature,Aerodynamic roughness, Surface resistance


QC 20100614
APA, Harvard, Vancouver, ISO, and other styles
7

Manrique-Sunen, A. "The treatment of vegetation in land surface models : implications for predictions of land-atmosphere exchange." Thesis, University of Reading, 2016. http://centaur.reading.ac.uk/68719/.

Full text
Abstract:
Plant processes affect fluxes of energy, moisture and CO2 between the land and the atmosphere. Land surface models need to correctly represent the vegetation functioning and its response to environmental conditions. Due to anthropogenic carbon emissions rising, and global warming, plant processes are being affected and in turn modulate the terrestrial carbon sink. However, models still disagree on the response of plants to changing conditions. This work analyses how vegetation is treated in two land surface models: the Joint UK Land Environment Simulator (JULES) and Carbon Hydrology Tiled ECMWF Scheme for Surface Exchanges over Land (CTESSEL). The aim is to analyse how environmental variables control the vegetation processes at daily and seasonal timescales at present day climate and the changes that arise in a scenario of double atmospheric CO2 and higher temperature. The analyses are carried out at the leaf level and at the canopy level. To investigate the responses at the leaf level, the photosynthesis scheme used in each model was extracted, thereby providing a submodel that can be run in stand alone mode. The photosynthesis submodel provides a means to analyse the leaf level response of each photosynthesis model to environment variables as well as the internal model parameters that characterise each plant type. In JULES the environmental controls on photosynthesis are explicitly introduced by three limiting regimes: light, rubisco (carbon) or export limiting regime. In CTESSEL the carbon and light limitations are implicitly represented but there is no export limitation. Due to the lack of export limiting regime, CTESSEL presents higher sensitivity to CO2 concentration resulting in a stronger CO2 fertilization effect. The carbon and energy fluxes produced by the full land surface models were tested and compared at 10 European FLUXNET sites. The main differences between modellled carbon fluxes were found to be the treatment of soil moisture stress and the lack of export limiting regime in CTESSEL. The optimum temperature for photosynthesis in models is the result of model parameters’ dependence on temperature and the combination of limiting regimes. The optimum temperature for photosynthesis was found to be a determining element in the strength and sign of the vegetation modelled feedback to climate change.
APA, Harvard, Vancouver, ISO, and other styles
8

McCutcheon, Michael Warren. "Analysis of a 2-3 exchange symmetric neutrino mass matrix." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=79048.

Full text
Abstract:
We present an analysis of the requirements of a 2--3 exchange symmetry in the neutrino mass matrix in comparison to the experimentally allowed ranges of neutrino oscillation parameters. The symmetric matrix, being defined at an energy scale appropriate to a right-handed neutrino in a See-saw scheme of mass suppression, is subject to evolution under Supersymmetric Renormalisation Group Equations, in order to interpret the matrix at experimental energies. By way of motivation we discuss the status of neutrino mass in the Standard Model and justify the context of the analysis by examining the mechanisms and evidence for oscillations. We then review the See-saw mechanism and also the process of renormalisation and its implications for bridging disparate energy scales. We present the relevant Renormalization Group Equations and demonstrate the parameterisation of pertinent Renormalization Group effects. Finally, we review previous work analysing this symmetry before updating some of these results and extending the analysis to its global behaviour in the space of both solar and atmospheric neutrino oscillation parameters.
APA, Harvard, Vancouver, ISO, and other styles
9

Elghanduri, Nagia E. "CFD investigation of mass exchange at the fluid/porous interface." Thesis, University of Aberdeen, 2012. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=189506.

Full text
Abstract:
Turbulent flow over a permeable layer is found in many natural systems such as gravel bed streams, as well as in many artificial structures. For this kind of flow, the flow domain consists of a free stream zone and a porous zone each zone have distinctly different flow features. The interface between these two flow zones is much less understood than both free stream and porous media flows. Further investigations are required in order to improve understanding of mass and momentum exchange processes, which take place within the interface zone, where free surface flow and porous media flow affect and alter each other. This thesis presents a computational fluid dynamic (CFD) investigation of turbulent flow and a tracer migration in a system, consists of a free surface and a permeable layer. Five cases, covering a range of flow depths and porosities of permeable layer, were analysed. The detailed two-dimensional flow simulations were carried out and were validated using the experimental results of Prinos et al. (2003). The results of simulations were up-scaled by spatial averaging over the free stream zone and the porous zone. In this project, the penetration depth associated with momentum and mass penetration. The results show that increasing either the water depth or porosity of the porous layer increases the both roughness mass penetration thicknesses. Several models were applied (i) a one-box model containing advection and the dispersion in the free-surface; (ii) a two-box model containing the advection and the dispersion in both the free-surface and the porous zone. (iii) a three-box model with the interface zone in between the free stream and the porous zone. The parameters for all these models were evaluated and then cross-compared. The three-box conceptual model is novel, and it represents the main contribution from this thesis.
APA, Harvard, Vancouver, ISO, and other styles
10

Burke, John Edmund. "Deuterium exchange mass spectrometry studies of the phospholipase A₂ superfamily." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p3331372.

Full text
Abstract:
Thesis (Ph. D.)--University of California, San Diego, 2008.
Title from first page of PDF file (viewed December 16, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Mass exchange of land"

1

GOVERNMENT, US. Colorado land exchange. [Washington, D.C.?: U.S. G.P.O., 1996.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

US GOVERNMENT. Alaska land exchange agreement. [Washington, D.C: U.S. G.P.O., 2002.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Weis, David D., ed. Hydrogen Exchange Mass Spectrometry of Proteins. Chichester, UK: John Wiley & Sons, Ltd, 2016. http://dx.doi.org/10.1002/9781118703748.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

US GOVERNMENT. Oregon Land Exchange Act of 2000. [Washington, D.C: U.S. G.P.O., 2000.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Malhuret, Claude. Mass deportations in Ethiopia. [Paris]: Medecins Sans Frontieres, 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

United States. Congress. Senate. Committee on Energy and Natural Resources. Columbia Basin land exchange: Report (to accompany S. 378). [Washington, D.C.?: U.S. G.P.O., 1995.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Resources, United States Congress Senate Committee on Energy and Natural. Columbia Basin land exchange: Report (to accompany S. 378). [Washington, D.C.?: U.S. G.P.O., 1995.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

United States. Congress. Senate. Committee on Energy and Natural Resources. Columbia Basin land exchange: Report (to accompany S. 378). [Washington, D.C.?: U.S. G.P.O., 1995.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

United States. Congress. Senate. Committee on Energy and Natural Resources. Idaho Land Exchange Act: Report (to accompany S. 1893). [Washington, D.C.?: U.S. G.P.O., 1992.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

United States. Bureau of Land Management. Albuquerque Field Office. Final environmental impact statement for Santo Domingo Pueblo/Bureau of Land Management land exchange. Albuquerque, N.M: U.S. Dept. of the Interior, Bureau of Land Management, Albuquerque Field Office, 2002.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Mass exchange of land"

1

Levinson, David M., and Kevin J. Krizek. "Exchange." In Metropolitan Transport and Land Use, 109–21. Second edition. | New York : Routledge, 2018.: Routledge, 2018. http://dx.doi.org/10.4324/9781315684482-7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Jensen, Pernille Foged, and Kasper D. Rand. "Hydrogen Exchange." In Hydrogen Exchange Mass Spectrometry of Proteins, 1–17. Chichester, UK: John Wiley & Sons, Ltd, 2016. http://dx.doi.org/10.1002/9781118703748.ch1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Ibbeken, Hillert, and Ruprecht Schleyer. "Mass Balances on Land." In Source and Sediment, 194–206. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-76165-2_16.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Wilson, Derek J. "Millisecond Hydrogen Exchange." In Hydrogen Exchange Mass Spectrometry of Proteins, 73–91. Chichester, UK: John Wiley & Sons, Ltd, 2016. http://dx.doi.org/10.1002/9781118703748.ch5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Yan, Xuguang, and Claudia S. Maier. "Hydrogen/Deuterium Exchange Mass Spectrometry." In Mass Spectrometry of Proteins and Peptides, 255–71. Totowa, NJ: Humana Press, 2009. http://dx.doi.org/10.1007/978-1-59745-493-3_15.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Cook, James. "The Mass cycle, insularity, and cultural exchange." In The Cyclic Mass, 1–18. Abingdon, Oxon ; New York, NY : Routledge, 2019. | Series: Royal Musical Association monographs ; 33: Routledge, 2019. http://dx.doi.org/10.4324/9781351042383-1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Onuch, Olga. "The Activist and Elite Interaction and Information Exchange Game." In Mapping Mass Mobilization, 157–82. London: Palgrave Macmillan UK, 2014. http://dx.doi.org/10.1057/9781137409775_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Kaltashov, Igor A., Rinat R. Abzalimov, Guanbo Wang, and Cedric E. Bobst. "Top-Down Hydrogen Exchange Mass Spectrometry." In Hydrogen Exchange Mass Spectrometry of Proteins, 149–64. Chichester, UK: John Wiley & Sons, Ltd, 2016. http://dx.doi.org/10.1002/9781118703748.ch9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Wang, Loo Chien, Srinath Krishnamurthy, and Ganesh Srinivasan Anand. "Hydrogen Exchange Mass Spectrometry Experimental Design." In Hydrogen Exchange Mass Spectrometry of Proteins, 19–35. Chichester, UK: John Wiley & Sons, Ltd, 2016. http://dx.doi.org/10.1002/9781118703748.ch2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Forest, Eric, and Martial Rey. "Proteases for Hydrogen Exchange Mass Spectrometry." In Hydrogen Exchange Mass Spectrometry of Proteins, 93–105. Chichester, UK: John Wiley & Sons, Ltd, 2016. http://dx.doi.org/10.1002/9781118703748.ch6.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Mass exchange of land"

1

Cirligeanu, Radu, Alina Bogoi, and Radu D. Rugescu. "TRANSIT Code for Unsteady Flows in Solar-Gravity Draught Turbine Towers." In ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-22518.

Full text
Abstract:
Unsteady, non-isentropic, discontinuous flows with energy exchange, during solar heating transients of air turbine towers are approached through a proprietary computational front method, initially developed for the study of ignition in solid propellant rocket motors. Its application in the discontinuous flows with energy exchange also proves highly efficient. Computational efficiency is demonstrated by CFD simulation of transients in the air accelerator of the SEATTLER solar mirror, turbine tower. This is a typically unsteady flow simulation for slender channels. A 1-D computational scheme was developed to simulate the interference between zones with different flow conditions. Given values for the thermochemical properties of the working gas are considered and two zones of different flow characteristics are identified. The first zone is the heat exchanger, where a nonisentropic flow develops. At the aft end of this heating zone a second zone of the channel is encountered after a blunt passage, where an isentropic expansion of the gas begins and extends along the tower up to the upper exit. Into the 1-D, unsteady flow scheme of computation, the discontinuity of equations of motion at the interface between the two zones induces very specific precautions and this methodology is detailed into the paper. Consequently, the computational front scheme covers the dual behavior of the fully non-isentropic flow with mass addition and mixing in the heater and of the fully isentropic flow at the exhaust of the gravity draught tall tower, typical for the solar-gravity draught power plants. Small perturbations of the flow, in the form of developing weak shocks, and blunt discontinuities are simultaneously covered. Code robustness is demonstrated and revealed through diagrams. The 1-D numerical scheme is based on the enhanced method of the computational front with resolution of the expansion wave development.
APA, Harvard, Vancouver, ISO, and other styles
2

Xie, G. N., Q. Y. Chen, M. Zeng, and Q. W. Wang. "Thermal Design of Heat Exchanger With Fins Inside and Outside Tubes." In ASME Turbo Expo 2006: Power for Land, Sea, and Air. ASMEDC, 2006. http://dx.doi.org/10.1115/gt2006-90260.

Full text
Abstract:
Compact heat exchangers such as tube-fin types and plate-fin types are widely used for gas-liquid or gas-gas applications. Some examples are air-coolers, fan coils, regenerators and recuperators in micro-turbines. In this study, thermal design of fin-and-tube (tube-fin) heat exchanger performance with fins being employed outside and inside tubes was presented, with which designed plate-fin heat exchanger was compared. These designs were performed under identical mass flow rate, inlet temperature and operating pressure on each side for recuperator in 100kW microturbine as well as specified allowable fractions of total pressure drop by means of Log-Mean Temperature Difference (LMTD) method. Heat transfer areas, volumes and weights of designed heat exchangers were evaluated. It is shown that, under identical heat duty, fin-and-tube heat exchanger requires 1.8 times larger heat transfer area outside tubes and volume, 0.6 times smaller heat transfer area inside tubes than plate-fin heat exchanger. Under identical total pressure drop, fin-and-tube heat exchanger requires about 5 times larger volume and heat transfer area in gas-side, 1.6 times larger heat transfer area in air-side than plate-fin heat exchanger. Total weight of fin-and-tube heat exchanger is about 2.7 times higher than plate-fin heat exchanger, however, the heat transfer rate of fin-and-tube heat exchanger is about 1.4 times larger than that of plate-fin heat exchanger. It is indicated that, both-sides finned tube heat exchanger may be used in engineering application where the total pressure drop is severe to a small fraction and the operating pressure is high, and may be adopted for recuperator in microturbine.
APA, Harvard, Vancouver, ISO, and other styles
3

Wilson, David Gordon. "Effect of Face-Area Ratio on Heat-Exchanger Pressure Drops, Size and Weight." In ASME Turbo Expo 2009: Power for Land, Sea, and Air. ASMEDC, 2009. http://dx.doi.org/10.1115/gt2009-60350.

Full text
Abstract:
Designers of heat exchangers of all types normally have several degrees of freedom even while meeting the specified effectiveness exactly. One freedom is that of choosing the face-area ratios for the two (or more) fluids. A principal reason for choosing face-area ratio is to arrive at desired pressure drops for the fluids. The lowest pressure drop is not always beneficial: a low pressure drop can produce highly non-uniform flow that would degrade heat-exchanger performance. Obviously a high pressure drop penalizes system performance directly. In this paper it is shown that choosing face-area ratio is a good tool up to a point, one at which penalties in the form of increased size and cost of the overall heat exchanger begin to outweigh the benefits. This paper reports studies on the effects of choosing face-area ratios on rotary regenerative heat exchangers, but most results are applicable to fixed-surface recuperative heat exchangers also. However, one significant difference between the two types is that gas-turbine regenerators have short flow lengths, the thickness of the disk or drum. A short flow length is a virtue, because it reduces the regenerator disk volume and mass. But the disk thickness must not be allowed to be reduced to the point where there is substantial “short-circuit” thermal conduction between the hot and cold faces of a regenerator. These and other aspects of heat-exchanger design are explored in general and by means of examples, and design guidelines are suggested.
APA, Harvard, Vancouver, ISO, and other styles
4

Wilson, Merrill A., Kurt Recknagle, and Kriston Brooks. "Design and Development of a Low-Cost, High Temperature Silicon Carbide Micro-Channel Recuperator." In ASME Turbo Expo 2005: Power for Land, Sea, and Air. ASMEDC, 2005. http://dx.doi.org/10.1115/gt2005-69143.

Full text
Abstract:
Typically, ceramic micro-channel devices are used for high temperature heat exchangers, catalytic reactors, electronics cooling, and processing of corrosive streams where the thermomechanical benefits of ceramic materials are desired. These benefits include: high temperature mechanical and corrosion properties and tailorable material properties such as thermal expansion, electrical conductivity and thermal conductivity. In addition, by utilizing Laminated Object Manufacturing (LOM) methods, inexpensive ceramic materials can be layered, featured and laminated in the green state and co-sintered to form monolithic structures amenable to mass production. In cooperation with the DOE and Pacific Northwest National Labs, silicon carbide (SiC) based micro-channel recuperator concepts are being developed and tested. The performance benefits of a high temperature, micro-channel heat exchanger are realized from the improved thermal efficiency of the high temperature cycles and the improved effectiveness of micro-channels for heat transfer. In designing these structures, the heat and mass transfer within the micro-channels are being analyzed with heat transfer models, computational fluid dynamics models and validated with experimental results. As an example, a typical micro-turbine cycle was modified and modeled to incorporate this ceramic recuperator and it was found that the overall thermal efficiency of the micro-turbine could be improved from about 27% to over 40%. Process improvements require technical advantages and cost advantages. These LOM methodologies have been based on well-proven industry standard processes where labor, throughput and capital estimates have been tested. Following these cost models and validation at the prototype scale, cost estimates were obtained. For the micro-turbine example, cost estimates indicate that the high-temperature SiC recuperator would cost about $200 per kWe. The development of these heat exchangers is multi-faceted and this paper focuses on the design optimization of a layered micro-channel heat exchanger, its performance testing, and fabrication development through LOM methodologies.
APA, Harvard, Vancouver, ISO, and other styles
5

Kyritsis, Vasileios E., and Pericles Pilidis. "An Analytical Approach for Gas Turbine Parameter Corrections." In ASME Turbo Expo 2008: Power for Land, Sea, and Air. ASMEDC, 2008. http://dx.doi.org/10.1115/gt2008-50716.

Full text
Abstract:
Turbomachinery component behavior depends on dimensionless parameters, such as inlet and circumferential Mach numbers and the ratio of specific heats. Regarding mass flow and speed, their dimensionless scaling parameters are usually used instead based on Mach number similarity. A given dimensionless aerodynamic operating point is defined by certain values of axial and circumferential Mach numbers. To such a point and for a certain value of isentropic exponent, a given dimensionless enthalpy variation corresponds as the work parameter. When turbo-machinery performance sizes, such as the work parameter and efficiency, are plotted against mass flow and speed to form a characteristic, the absence of the isentropic exponent as an additional dimension causes inaccuracies. The extent of the inaccuracies firstly depends on the scaling groups used for mass low, speed and work, that is whether they include the gas property parameters, such as the isentropic exponent and the gas constant. The aforementioned shows that for rigorous calculations correction factors have to be applied, especially when quasi-dimensionless groups are used and/or pressure ratio is used as the work parameter. Typically, the corrections for mass flow and speed may take the form of multipliers, which consist of ratios of the isentropic exponent and/or the gas constant between the examined condition and the reference one. Alternatively, for the case of mass flow the exponents of temperature and pressure can deviate from their theoretical values of 0.5 and 1.0 respectively. Scope of the current work is the mathematical formulation of such exponents for a variety of scaling groups regarding mass flow, speed and work. The correction factors are a strong function of the operating condition, temperature and gas composition, which fully define gas properties. Among the findings of the current study, evidence is provided that the practically one-to-one relationship considered between dimensionless mass flow and inlet Mach number holds for low Mach number values. This is particularly true, since its sensitivity to variations of the isentropic exponent gets increasingly larger with Mach number. Additionally, for a given dimensionless enthalpy change, the exchange rate of pressure ratio against variations of the isentropic exponent is much more increased for an expansion rather than a compression. The latter justifies the use of dimensionless enthalpy drop in turbine characteristics.
APA, Harvard, Vancouver, ISO, and other styles
6

Demargne, A. A. J., and J. P. Longley. "The Aerodynamic Interaction of Stator Shroud Leakage and Mainstream Flows in Compressors." In ASME Turbo Expo 2000: Power for Land, Sea, and Air. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/2000-gt-0570.

Full text
Abstract:
The aerodynamics of stator shroud leakage and mainstream flow interactions have been investigated using a linear cascade in which leakage mass flow and tangential velocity could be varied independently. Experimental measurements confirm the detrimental effect of increasing leakage mass flow rate, but also show clearly that increasing cavity tangential velocity improves the performance of the blade row. Shroud leakage is also found to modify significantly the spanwise distribution of blockage, flow turning and loss at exit of the stator passage. The mechanisms behind these large-scale effects are identified and a description of the interaction process based on momentum thickness arguments is proposed. Experimental and numerical results show that the amount of leakage is a linear function of the difference between cavity pressure and average pressure on the hub upstream of the stator. This result is shown to be an axisymmetric result, and thus largely independent of the pitchwise variation in blade loading. Departures from linearity at low leakage fractions are associated to the blade loading inducing pitchwise non-uniformities in the structure of the flow at the interface between the shroud cavity and the mainstream. These non-uniformities involve vortical structures, which participate in the exchange of fluid and momentum between the cavity and the mainstream, even at zero net leakage. Experiments also show that these non-uniformities in flow structure contribute to the generation of loss.
APA, Harvard, Vancouver, ISO, and other styles
7

Zhou, Chao, and Howard Hodson. "The Tip Leakage Flow of an Unshrouded High Pressure Turbine Blade With Tip Cooling." In ASME Turbo Expo 2009: Power for Land, Sea, and Air. ASMEDC, 2009. http://dx.doi.org/10.1115/gt2009-59637.

Full text
Abstract:
Experimental, analytical and numerical methods have been employed to study the aerodynamic performance of four different cooled tips with coolant mass ratios between zero and 1.2% at three tip gaps of 1%, 1.6% and 2.2% of the chord. The four cooled tips are two flat tips with different coolant holes, a cooled suction side squealer tip and a cooled cavity tip. Each tip has ten coolant holes with the same diameter. The uncooled cavity tip produces the smallest loss among all uncooled tips. On the cooled flat tip, the coolant is injected normally into the tip gap and mixes directly with flow inside the tip gap. The momentum exchange between the coolant and the flow that enters the tip gap creates significant blockage. As the coolant mass flow ratio increases, the tip leakage loss of the cooled flat tip first decreases and then increases. For the cooled cavity tip, the blockage effect of the coolant is not as big as that on the cooled flat tip. This is because after the coolant exits the coolant holes, it mixes with flow in the cavity first, and then mixes with tip flow in the tip gap. The tip leakage loss of the cooled cavity tip increases as the coolant mass flow ratio increase. As a result, at a tip gap of 1.6% of the chord, the cooled cavity tip gives the lowest loss. At the smallest tip gap of 1% of the chord, the cooled flat tip produces less loss than the cooled cavity tip when the coolant mass flow ratios larger than 0.23%. This is because with the same coolant mass flow ratio, a proportionally larger blockage is created at the smallest tip gap. At the largest tip gap of 2.2% of the chord, the cavity tip achieves the best aerodynamic performance. This is because, the effect of the coolant is reduced and the benefits of the cavity tip geometry dominate. At a coolant mass flow ratio of 0.55%, the cooled flat tips produce a lower loss than the cavity tip at tip gaps less than 1.3% of the chord. The cooled cavity tip produces the least loss for tip gaps larger than 1.3% of the chord. The cooled suction side squealer has the worst aerodynamic performance for all tip gaps studied.
APA, Harvard, Vancouver, ISO, and other styles
8

Das, Kaushik, Awatef A. Hamed, and Debashis Basu. "Droplet Trajectories and Collection on Fan Rotor at Off-Design Conditions." In ASME Turbo Expo 2006: Power for Land, Sea, and Air. ASMEDC, 2006. http://dx.doi.org/10.1115/gt2006-91214.

Full text
Abstract:
A numerical investigation is conducted to study water droplet collection on a high bypass turbofan engine booster rotor under different rotational speeds. An Eulerian-Lagrangian approach is used in formulating the flow and droplet governing equations in the rotating reference frame. A one-way interaction model is used to model the effects of momentum and energy exchange effects with the flow on the droplets as they travel through the rotor. Results are presented for the computed flow field, droplet trajectories, water collection efficiency and droplet exit mass and temperature profiles at 60%, 70%, 80%, 90%, and 100% design rotational speeds. The highest collection is predicted near the tip at the pressure surfaces leading edge. It then drops considerably at 40%–60% of the booster rotor blade chord and remains low over the aft portion of the pressure side. In general, the rotor blade collection efficiency is strongly influenced by rotor speed and increases as the rotational speed decreases.
APA, Harvard, Vancouver, ISO, and other styles
9

Bagnoli, M., and A. De Pascale. "Performance Evaluation of a Small Size Cogenerative System Based on a PEM Fuel Cell Stack." In ASME Turbo Expo 2005: Power for Land, Sea, and Air. ASMEDC, 2005. http://dx.doi.org/10.1115/gt2005-68451.

Full text
Abstract:
The use of fuel cell systems for distributed generation represents an interesting option due to the intrinsic high efficiency and the potential to reduce the environmental impact of power supply in comparison with thermoelectric plants. In this paper the study of a cogenerative energy system based on a Proton Exchange Membrane fuel cell stack, that should satisfy a small electric utility, is reported; the capability of this cogenerative system to supply electrical and thermal power demand of a civil user has been investigated. In this research the electric efficiency has been calculated as net electric power on chemical power given to the system and the thermal efficiency as thermal power given to user on chemical power in input. Moreover, an energy saving index has been introduced to assess the cogenerative performance of this energy system. The investigation has been developed by experimenting an existing stack of fuel cell and studying its behaviour with a variable power demand. In particular, all the input and output mass flows have been evaluated to have parameters through which the operation of the whole cogenerative system, made by fuel cell stack and all the auxiliaries like compressor and pumps, could be simulated.
APA, Harvard, Vancouver, ISO, and other styles
10

Zhang, Huisheng, Shilie Weng, and Ming Su. "Dynamic Modeling and Simulation of Distributed Parameter Heat Exchanger." In ASME Turbo Expo 2005: Power for Land, Sea, and Air. ASMEDC, 2005. http://dx.doi.org/10.1115/gt2005-68293.

Full text
Abstract:
The heat exchanger is one of the key components for an advanced gas turbine power plant. This paper presents a new modeling technique to solve the iterative calculation for the coupling of pressure and mass flow rate in the flow system of a distributed parameter heat exchanger. In this modeling method, a control volume is separated into a volume unit and a flow resistance unit. The volume unit takes into account the flow rate difference between the inlet and outlet of the control volume, and the flow resistance unit considers the pressure drop in the control volume. Thus a single set of ordinary differential equations is obtained. When we adopt this modeling technique, a non-iterative dynamic model of heat exchanger can be established based on conservation theorems. A single plate-fin heat exchanger for the inter-cooled recuperated gas turbine engine is taken as an example to study the steady state and dynamic performance of the heat exchanger and to verify this modeling technique. The simulation results are reasonable, and the results satisfy the requirement of the real time model. This provides a powerful tool for the dynamic simulation and optimization design of advanced gas turbine power system.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Mass exchange of land"

1

Cimmery, Vern. A methodology for determining mass movement susceptibility for land-use planning. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.2357.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

A.L. Roquemore and S.S. Medley. The TFTR E Parallel B Spectrometer for Mass and Energy Resolved Multi-Ion Charge Exchange Diagnostics. Office of Scientific and Technical Information (OSTI), January 1998. http://dx.doi.org/10.2172/4580.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Churchill, J. H., and D. G. Aubrey. Use of GPS-Tracked Drifters to Study Water Mass Exchange and Horizontal Dispersion near a Tidal Inlet. Fort Belvoir, VA: Defense Technical Information Center, May 1996. http://dx.doi.org/10.21236/ada310619.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Timothy J. Griffis and John M. Baker. Technical Report: Impacts of Land Management and Climate on Agroecosystem Greenhouse Gas Exchange in the Upper Midwest United States. Office of Scientific and Technical Information (OSTI), July 2007. http://dx.doi.org/10.2172/953624.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Roblyer, S. P. Calculation of 1.25% 235U enriched UO2 solution safe slab, safe cylinder diameter, minimum safe mass, and ion exchange module for the CVDF. Office of Scientific and Technical Information (OSTI), June 1997. http://dx.doi.org/10.2172/325429.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Wharton, Sonia, Matthew Simpson, Jessica Osuna, Jennifer Newman, and Sebastien Biraud. The Role of Surface Energy Exchange for Simulating Wind Inflow: An Evaluation of Multiple Land Surface Models in WRF for the Southern Great Plains Site Field Campaign Report. Office of Scientific and Technical Information (OSTI), May 2016. http://dx.doi.org/10.2172/1254173.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Estimating ground-water exchange with lakes using water-budget and chemical mass-balance approaches for ten lakes in ridge areas of Polk and Highlands counties, Florida. US Geological Survey, 1998. http://dx.doi.org/10.3133/wri984133.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Mass exchange of land' for particular source types:
Journal articles Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography