A unidirectional water flux model of fruit growth

1990 ◽  
Vol 68 (6) ◽  
pp. 1286-1290 ◽  
Author(s):  
D. R. Lee
Keyword(s):  
Mathematical Model ◽  
Prunus Avium ◽  
Water Flux ◽  
Radiant Energy ◽  
Fruit Growth ◽  
Water Evaporation ◽  
Unidirectional Flux ◽  
Flux Model ◽  
Phloem Translocation ◽  
Correct Size

A mathematical model of fruit growth has been developed based upon a unidirectional flux of solution into the fruit. The model relies entirely upon the physical process of diffusion and water evaporation driven by radiant energy and does not invoke any requirement for metabolic inputs by the developing fruit. The model will "grow" fruit of different varieties of different species to the correct size in the correct time. Key words: Lycopersicon esculentum, tomato, Prunus avium, cherry, fruit growth, phloem, translocation, transpiration, model.

scholarly journals Evapotranspiration from a riparian fen wetland

2005 ◽  
Vol 36 (2) ◽  
pp. 121-135 ◽  
Author(s):  
H.E. Andersen ◽  
S. Hansen ◽  
H. E. Jensen
Keyword(s):  
Driving Forces ◽  
Radiant Energy ◽  
Vapour Pressure Deficit ◽  
Open Water ◽  
Absolute Magnitude ◽  
Growing Season ◽  
Agricultural Landscapes ◽  
Water Evaporation ◽  
Evaporative Demand ◽  
Fine Grained

Evapotranspiration rates were measured in a riparian fen wetland dominated by vascular vegetation and surrounded by open agricultural areas and forests. The wetland is situated on a floodplain in central Denmark. Measurements were taken throughout the growing season (April–September) of 1999. Evapotranspiration rates were higher than those published for most other wetland types, with an average of 3.6 mm d−1 during the growing season and a peak rate of 5.6 mm d−1. Daily average evapotranspiration was 110% of Penman's potential open water evaporation. Evapotranspiration was the dominant sink in the energy balance of the wetland studied. During the day, evapotranspiration accounted for 82% of the available radiant energy, Rn. Due to the presence of deposited fine-grained sediments, soil-water availability was kept high at all times which resulted in moderate canopy resistances, rc (overall mean =32 s m−1). Evapotranspiration was controlled by a combination of driving forces: Rn, saturation vapour pressure deficit, D, and rc. It is hypothesized that the results presented in this study are conditioned by the proximity of the wetland to drier upland areas. During periods with high evaporative demand and low precipitation, warm, dry air is formed over the upland areas and wetland evapotranspiration rates are enhanced by local advection. Indicative evidence for the hypothesis is presented. Although the absolute magnitude of the results reported is only directly relevant to similar sites in Denmark, the processes and controls described are considered to be representative of riparian wetlands subjected to frequent flooding and/or with a high groundwater table, with vascular vegetation, and which are narrow corridors in open agricultural landscapes.

A coupled carbon and water flux model to predict vegetation structure

1996 ◽  
Vol 7 (5) ◽  
pp. 651-666 ◽  
Author(s):  
Alex Haxeltine ◽  
I. Colin Prentice ◽  
Ian David Creswell
Keyword(s):  
Vegetation Structure ◽  
Water Flux ◽  
Flux Model

scholarly journals A MATHEMATICAL MODEL FOR DIRECT EVAPORATIVE COOLING AIR CONDITIONING SYSTEM

2003 ◽  
Vol 2 (2) ◽  
Author(s):  
J. R. Camargo ◽  
C. D. Ebinuma ◽  
S. Cardoso
Keyword(s):  
Mathematical Model ◽  
Air Conditioning ◽  
Cooling System ◽  
Convective Heat Transfer Coefficient ◽  
Evaporative Cooling ◽  
Experimental Tests ◽  
Water Evaporation ◽  
Human Thermal Comfort ◽  
Direct Evaporative Cooling ◽  
Evaporative Cooling System

Air conditioning systems are responsible for increasing men's work efficiency as well for his comfort, mainly in the warm periods of the year. Currently, the most used system is the mechanical vapor compression system. However, in many cases, evaporative cooling system can be an economical alternative to replace the conventional system, under several conditions, or as a pre-cooler in the conventional systems. It leads to a reduction in the operational cost, comparing with systems using only mechanical refrigeration. Evaporative cooling operates using induced processes of heat and mass transfer, where water and air are the working fluids. It consists in water evaporation, induced by the passage of an air flow, thus decreasing the air temperature. This paper presents the basic principles of the evaporative cooling process for human thermal comfort, the principles of operation for the direct evaporative cooling system and the mathematical development of the equations of thermal exchanges, allowing the determination of the effectiveness of saturation. It also presents some results of experimental tests in a direct evaporative cooler that take place in the Air Conditioning Laboratory at the University of Taubaté Mechanical Engineering Department, and the experimental results are used to determinate the convective heat transfer coefficient and to compare with the mathematical model.

Comparison of Uniform and Non-uniform Water Flux Density Approaches Applied on a Mathematical Model of Heat Transfer and Solidification for a Continuous Casting of Round Billets

2014 ◽  
Vol 46 (1) ◽  
pp. 366-377 ◽  
Author(s):  
Charles Sostenes Assuncao ◽  
Roberto Parreiras Tavares ◽  
Guilherme Oliveira ◽  
Luiz Carlos Pereira
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Continuous Casting ◽  
Flux Density ◽  
Water Flux ◽  
Heat Transfer And Solidification

scholarly journals THEORY OF EVAPOTRANSPIRATION: 2. Soil and intercepted water evaporation

2011 ◽  
Vol 59 (2) ◽  
pp. 73-84 ◽  
Author(s):  
Anatolij Budagovskyi ◽  
Viliam Novák
Keyword(s):  
Water Flux ◽  
Heat Fluxes ◽  
Water Evaporation ◽  
Temperature Profiles ◽  
Measured Temperature ◽  
Net Radiation ◽  
Air Humidity ◽  
Indirect Methods ◽  
The Difference ◽  
Evapotranspiration Estimation

THEORY OF EVAPOTRANSPIRATION: 2. Soil and intercepted water evaporationEvaporation of water from the soil is described and quantified. Formation of the soil dry surface layer is quantitatively described, as a process resulting from the difference between the evaporation and upward soil water flux to the soil evaporating level. The results of evaporation analysis are generalized even for the case of water evaporation from the soil under canopy and interaction between evaporation rate and canopy transpiration is accounted for. Relationships describing evapotranspiration increase due to evaporation of the water intercepted by canopy are presented. Indirect methods of evapotranspiration estimation are discussed, based on the measured temperature profiles and of the air humidity, as well as of the net radiation and the soil heat fluxes.

Modeling of work of plate water evaporation coolers of indirect operation principle

10.12737/2199 ◽  
2014 ◽  
Vol 3 (4) ◽  
pp. 160-166
Author(s):  
Шацкий ◽  
Vladimir Shatskiy ◽  
Гулевский ◽  
Vyacheslav Gulevskiy
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Boundary Conditions ◽  
Cross Section ◽  
Parabolic Type ◽  
Water Evaporation ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Proposed Model ◽  
Complex Mathematical Model

More complex mathematical model is proposed which is a system of partial differential equations of elliptic and parabolic type with the corresponding initial and boundary conditions, which are not involved in the heat transfer coefficients, the deter-mination of the numerical values of which is very difficult. For its implementation diffe-rence analogue of the proposed model was built with Nx steps along the length of the channel, Ny steps along the section of channels, Ny / 2 +1 steps of the cross section of the plate. The presented model and the method of its implementation makes it possible to determine the temperature of the air flows along the length of coolers that offers a choice of the geometric parameters.

scholarly journals Correction to: Comparison of Uniform and Non-uniform Water Flux Density Approaches Applied on a Mathematical Model of Heat Transfer and Solidification for a Continuous Casting of Round Billets

2019 ◽  
Vol 50 (5) ◽  
pp. 2485-2485
Author(s):  
Charles Sostenes Assuncao ◽  
Roberto Parreiras Tavares ◽  
Guilherme Oliveira ◽  
Luiz F. P. Pereira
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Continuous Casting ◽  
Flux Density ◽  
Water Flux ◽  
Heat Transfer And Solidification

A mathematical model of water flux through aortic tissue

1979 ◽  
Vol 41 (1) ◽  
pp. 79-90 ◽  
Author(s):  
D KENYON
Keyword(s):  
Mathematical Model ◽  
Water Flux ◽  
Aortic Tissue

scholarly journals A MATHEMATICAL MODEL FOR DIRECT EVAPORATIVE COOLING AIR CONDITIONING SYSTEM

2003 ◽  
Vol 2 (2) ◽  
pp. 30 ◽  
Author(s):  
J. R. Camargo ◽  
C. D. Ebinuma ◽  
S. Cardoso
Keyword(s):  
Mathematical Model ◽  
Air Conditioning ◽  
Cooling System ◽  
Convective Heat Transfer Coefficient ◽  
Evaporative Cooling ◽  
Experimental Tests ◽  
Water Evaporation ◽  
Human Thermal Comfort ◽  
Direct Evaporative Cooling ◽  
Evaporative Cooling System

Air conditioning systems are responsible for increasing men's work efficiency as well for his comfort, mainly in the warm periods of the year. Currently, the most used system is the mechanical vapor compression system. However, in many cases, evaporative cooling system can be an economical alternative to replace the conventional system, under several conditions, or as a pre-cooler in the conventional systems. It leads to a reduction in the operational cost, comparing with systems using only mechanical refrigeration. Evaporative cooling operates using induced processes of heat and mass transfer, where water and air are the working fluids. It consists in water evaporation, induced by the passage of an air flow, thus decreasing the air temperature. This paper presents the basic principles of the evaporative cooling process for human thermal comfort, the principles of operation for the direct evaporative cooling system and the mathematical development of the equations of thermal exchanges, allowing the determination of the effectiveness of saturation. It also presents some results of experimental tests in a direct evaporative cooler that take place in the Air Conditioning Laboratory at the University of Taubaté Mechanical Engineering Department, and the experimental results are used to determinate the convective heat transfer coefficient and to compare with the mathematical model.

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