Academic literature on the topic 'Soil temperature – Mathematical models'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Soil temperature – Mathematical models.'
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 "Soil temperature – Mathematical models"
1
Dessureault-Rompré, Jacynthe, Bernie J. Zebarth, Alex Georgallas, David L. Burton, Cynthia A. Grant, and Craig F. Drury. "Temperature dependence of soil nitrogen mineralization rate: Comparison of mathematical models, reference temperatures and origin of the soils." Geoderma 157, no. 3-4 (July 2010): 97–108. http://dx.doi.org/10.1016/j.geoderma.2010.04.001.
Full text
2
Ryabkov, A. V., E. P. Martynenko, A. F. Zakuraev, and B. A. Ashabokov. "DEVELOPMENT OF MATHEMATICAL MODELS FOR STUDYOF GEOTECHNICAL PROPERTIES OF MARSHES." Oil and Gas Studies, no. 4 (September 1, 2016): 93–97. http://dx.doi.org/10.31660/0445-0108-2016-4-93-97.
Full textAbstract:
It is shown that failures at normal operation of pipeline transport occur largely due to the cyclical nature of degradation processes that are inherent in the system with various soil and swamp covers and are accompanied by sharp negative temperature gradients. A model of methane liberation processes was generated. The method of molecular beam epitaxy was analyzed, which permitted to capture the volume and cyclicity of methane liberation, to measure all noises and signals in different frequency ranges.
3
Park, Keunbo, Heekwon Yang, Bang Lee, and Dongwook Kim. "Development of Shallow-Depth Soil Temperature Estimation Model Based on Thermal Response in Permafrost Area." Applied Sciences 8, no. 10 (October 11, 2018): 1886. http://dx.doi.org/10.3390/app8101886.
Full textAbstract:
A soil temperature estimation model for increasing depth in a permafrost area in Alaska near the Bering Sea is proposed based on a thermal response concept. Thermal response is a measure of the internal physical heat transfer of soil due to transferred heat into the soil. Soil temperature data at different depths from late spring to the early autumn period at multiple permafrost sites were collected using automatic sensor measurements. From the analysis results, a model was established based on the relationship between the normalized cumulative soil temperatures (CRCST*i,m and CST*ud,m) of two different depths. CST*ud,m is the parameter of the soil temperature measurement at a depth of 5 cm, and CRCST*i,m is the parameter of the soil temperature measured at deeper depths of i cm (i = 10, 15, 20, and 30). Additionally, the fitting parameters of the mathematical models of the CRCST*i,m–CST*ud,m relationship were determined. The measured soil temperature depth profiles at a different site were compared with their predicted soil temperatures using the developed model for the model validation purpose. Consequently, the predicted soil temperatures at different soil depths using the soil temperature measurement of the uppermost depth (5 cm) were in good agreement with the measured results.
4
Shein, Ye V., A. G. Bolotov, and A. V. Dembovetskii. "Soil Hydrology of Agricultural Landscapes: Quantitative Description, Research Methods, and Availability of Soil Water." Eurasian Soil Science 54, no. 9 (September 2021): 1367–74. http://dx.doi.org/10.1134/s1064229321090076.
Full textAbstract:
Abstract Soil hydrology has deep Russian roots, which are primarily related to the theory of soil hydrological constants and their practical application. These constants have been used to assess the hydrological soil conditions in stationary observations, for which attempts to arrange regular hydrological observations in the landscape faced impracticable complexity of work and calculations and provided unreliable quantitative predictions. At present, there are new opportunities for experimental research, digital analysis, and prediction of hydrological indicators of soils in the landscape. A new quantitative approach to the use of digital technologies for monitoring soil water and temperature in the soils of agricultural landscapes, their dynamics, and their probabilistic calculations has been developed. Based on the soil map, it is proposed to create an information and measurement system with the studied thermal and hydrophysical characteristics of soils using mathematical models to calculate the dynamics of moisture and temperature for given periods and conditions of different availability of heat and precipitation, which allows us to quantify the availability of moisture reserves in the soils of the agricultural landscape. This system of observations, assessment, and forecast includes the use of modern technologies for determining soil water content and temperature, the adaptation of predictive physically based models for calculating the dynamics of moisture reserves depending on the availability of precipitation and conditions at the lower boundary of soil profiles. The paper deals with the hydrological analysis of soils by the example of the agricultural landscape of the Zelenograd station of the Dokuchaev Soil Science Institute in the village of El’digino, Pushkino district, Moscow oblast.
5
Shishkin, K. V., A. A. Belik, A. A. Kokoreva, and Z. S. Ezhelev. "Adequateness assessement of percolate and temperature model using MSU Large lysimeters." Dokuchaev Soil Bulletin, no. 99 (December 9, 2019): 76–91. http://dx.doi.org/10.19047/0136-1694-2019-99-76-91.
Full textAbstract:
The assessement of PEARL model adequateness was carried out on the basis of temperature and percolate data obtained by means of MSU Large Lysimeters. Lysimeters are used in experimental soil science mostly for investigating water balance and substance or ions transport from observed horizons or full soil profile. PEARL 4 model, the water prediction block of which is built on the basis of classical SWAP model, uses preferential water flow describing mechanism. Systematical observation of experimental soils in MSU Large lysimeters allowed obtaining extensive data on temperature and soil moisture dynamics, as well as percolate from bottom border. Thеsе measurements are unique and can become the basis for adaptation, verification and setting of mass and energy transfer models. It was shown, that mathematical parametric model requires adjustment for reaching reliable values of percolate from bottom border, moisture and temperature profiles. It can be achieved by selection of water retention curve (WTC) approximation parameters. It was noticed that the error for all predicted parameters increases in winter period. Thereby, the use of such matter transfer models in soil are problematic for long-term prognosis. For example, due to the annual error accumulation before the spring season such models cannot be applied for estimation of the risk of ground water pollution with agrochemicals.
6
Palamarchuk, Vitalii, and Oleksii Alieksieiev. "MATHEMATICAL MODELS OF HIGH-STARCH MAIZE HYBRIDS OF DIFFERENT GROUND GROUPS." Agriculture and Forestry, no. 1 (April 28, 2020): 28–47. http://dx.doi.org/10.37128/2707-5826-2020-1-3.
Full textAbstract:
The article presents the results of mathematical modeling based on the construction and usage of different images of an object, process or system. The research expected to study the dependence of the productivity level and the economically valuable features of corn hybrids in the form of mathematical models. Field studies were carried out during 2011-2017 at the field of research of the Department of Plant, Selection and Bioenergy Crops of SE EF “Kordelivske” of IP NAASU of Vinnytsia National Agrarian University under the conditions of the Forest-Steppe of the Right-Bank, in accordance with the recommendations presented in the Methodology Of The Maize Field Study. The soils in the study variants are represented by black earth soil of deep medium loamy on the loessial soil. The humus content (according to Tiurin) in the tilth soil was 4.60%. Soil reaction - pH (salt) 5.7. The soils contain lightly hydrolyzed nitrogen (according to Kornfield) 106 mg per 1 kg of soil, mobile phosphorus and exchangeable potassium (according to Chirikov) 186 and 160 mg per 1 kg of soil, respectively. The experiments established the economic and biological evaluation of corn hybrids depending on the sowing period, the size of the fraction and the depth of seed wrapping, foliar fertilizers by micro fertilizers. The plot area for hybrids was 10.5 m2. Repeatability in experiments for hybrids is 3 times. Placement of plots is by the method of randomized blocks. An ecological-genetic model of quantitative features was used to study the phenotypic productivity of maize hybrids and to establish the influence on the formation of their traits. The model construction is based on the hierarchy of production traits demonstration in ontogeny and the correspondence of their manifestation in organogenesis. The model consists of three modules of features, i.e. the resultant and two components which reflecting the phenotypic implementation of the genetic formula. Resulting features are those that have an environmentally stable relationships and the highest total contribution to the intended property, yield. As a result of the conducted research, the mathematical models of the duration of the growing season of early-maturing maize hybrids allowed us to determine that the biggest influence does sums of effective temperatures (≥ + 10° C) for May, June, August and September over correlation rate at r = -0.62 and r = -0.51, r = 0.59 and r = 0.39, respectively. Also precipitation amount significantly influenced on the duration of the growing season and the correlation coefficient was r = -0.44, and the influence of the HTI was at the level of r = -0.34. For middle-early hybrids the sum of effective temperatures (≥ + 10° C) in May and June r = -0.46 and r = -0.28, respectively, and also the sum of effective temperatures (≥ + 10° C) in August – r = 0.18 had a strong effect. However, for medium-maturing maize hybrids, the duration of the growing season was determined by the sum of effective temperatures (≥ + 10° C) for May, June and July – r = -0.37, r = -0.34 and r = -0.28, and the sum of effective temperatures (≥ + 10° C) in August – r = 0,18. It is also possible to note the influence and the total sum of effective temperatures (≥ + 10° C) during vegetation at the level of correlation coefficient r = -0.51. According to the research results of mathematical models of the influence of weather conditions on the formation of phenotypic productivity of maize hybrids of different maturity groups both general biological regularities and group differences of features formation were established. Thus, if we analyze the differences between groups of early-ripening and middle-early corn hybrids, their growth and development in general are influenced by the sum of the effective temperatures, rainfall and HTI. In fact, the studied groups of ripeness differ slightly and the main differences are observed only in the variability of the studied features or their close relationship with each other. However, middle-aged hybrids respond somewhat differently to environmental factors, which allow developing the elements of adaptive growing technology for each of the maturity groups. Key words: corn, hybrid, phenotype, mathematical model, productivity, economic and valuable features.
7
Wilson, David J., and Kanji Tamamushi. "Low-Temperature Thermal Treatment of Contaminated Soils: Simple Mathematical Models." Separation Science and Technology 28, no. 15-16 (November 1993): 2351–75. http://dx.doi.org/10.1080/01496399308019742.
Full text
8
Van, Sin'tun, Aleksey Kolos, and Andrey Petryaev. "Mathematical Modeling of the Process of Soil Freezing of Railway Subgrade in Cold Climate Con-ditions." Proceedings of Petersburg Transport University 19, no. 4 (December 20, 2022): 820–31. http://dx.doi.org/10.20295/1815-588x-2022-4-820-831.
Full textAbstract:
Purpose: Mathematical model for studying the process of soil freezing given moisture migration is developed. Numerical modeling of temperature mode of railway subgrade at non-stationary pro-cess in cold climate conditions is performed. Methods: Numerical implementation of the model is performed by mathematical module processing in COMSOL Multiphysics program, which’s based on partial differential equations (PDE), with finite element method. The model reliability is con-firmed by the comparison with previous experimental data and the results of simulation by other authors. Results: Calculation results on the developed model basis show the best correlation with experimental data in comparison with the results for other models. Calculation example and calcu-lation results for subgrade temperature mode in freezing-thawing fifth cycle are presented. The analysis of soil freezing depth change and soil temperature fluctuation change by depth by fifth year are carried out. Practical significance: The developed mathematical model makes it possible to predict soil freezing depth, taking into account moisture migration, including freezing and thawing depth changes caused by climate warming. The developed model can be used both, to study the mechanism of subgrade temperature mode distribution at freezing and thawing, and to improve subgrade construction for to protect it from soil frost heaving.
9
Tarnawski, Vlodek R., and Bernhard Wagner. "On the prediction of hydraulic conductivity of frozen soils." Canadian Geotechnical Journal 33, no. 1 (March 25, 1996): 176–80. http://dx.doi.org/10.1139/t96-033.
Full textAbstract:
This paper describes a mathematical model for predicting the hydraulic conductivity of partially frozen soils on the basis of limited input data such as grain size distribution and bulk density or porosity. A new model is based on an analogy for the hydraulic conductivity of frozen and unfrozen soils and models for the estimation of hydraulic properties of soils and unfrozen water content. Campbell's model was used for prediction of soil-water characteristics from limited data, while unfrozen water content was obtained from two models (by P.J. Williams and D.M. Anderson) applied to two different temperature ranges. The new model can be used for the rapid estimation of the hydraulic conductivity of practically any freezing soil having log-normal grain size distribution and for computer simulation of moisture migration in soils below the freezing point. An acceptable conformity between the model prediction and measured data for pure sand has been achieved. The computer program developed requires the following input data: grain size distribution, bulk density or porosity, and soil temperature. Key words: frozen soils, hydraulic conductivity, bulk density, grain size distribution, unfrozen water content.
10
Tong, Bing, Zhiqiu Gao, Robert Horton, and Linlin Wang. "Soil Apparent Thermal Diffusivity Estimated by Conduction and by Conduction–Convection Heat Transfer Models." Journal of Hydrometeorology 18, no. 1 (December 27, 2016): 109–18. http://dx.doi.org/10.1175/jhm-d-16-0086.1.
Full textAbstract:
Abstract Soil heat transfer is complex, and conduction-alone models may not always perform well in estimating soil apparent thermal diffusivity. Soil apparent thermal diffusivity is related to soil temperature change propagation rates. Soil temperature data collected at the Tazhong station in China were used to examine the characteristics of soil apparent thermal diffusivity determined by three different algorithms and the sum of vertical gradient of soil apparent thermal diffusivity and apparent water flux density . The results showed that 1) soil apparent thermal diffusivity obtained with a conduction–convection algorithm had a better agreement with soil apparent thermal diffusivity obtained with a phase algorithm than with soil apparent thermal diffusivity obtained with an amplitude algorithm except for the case of = 0; 2) when > 0, , and when < 0, ; 3) for a given soil temperature phase shift, increased (decreased) with increasing logarithmic amplitude attenuation when the phase shift was larger (smaller) than the logarithmic amplitude attenuation, reached a maximum value when the phase shift equaled the logarithmic amplitude attenuation, and increased with increasing logarithmic amplitude attenuation; and 4) for a given logarithmic amplitude attenuation, decreased with increasing phase shift and increased (decreased) with increasing phase shift when the phase shift was larger (smaller) than times the logarithmic amplitude attenuation. These mathematical conclusions were also confirmed with field data.
Dissertations / Theses on the topic "Soil temperature – Mathematical models"
1
Jean, Karm-Ervin. "Models Describing the Sea Level Rise in Key West, Florida." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2274.
Full textAbstract:
Lately, we have been noticing an unusual rise in the sea level near many Floridian cities. By 2060, scientists believe that the sea level in the city of Key West will reach between 22.86 to 60.96 centimeters (Strauss et al. 2012). The consequences of sea level rise are unpleasant by gradually tearing away our beaches and natural resources, destroying our homes and businesses, etc. Definitively, a continual increase of the sea level will affect everyone either directly or indirectly.
In this study, the sea level measurements of four Floridian coastal cities (including Key West) are collected in order to describe their trend toward sea level rise over the past 100 years. After the comparisons, some models describing the sea level rise in the city of Key West, Florida, are developed. Any inferences for these above cities may well be extended to similar ones.
2
Barrett, Gary Edward. "Infiltration in water repellent soil." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28618.
Full textAbstract:
Observations made at Goat Meadows - a small sub-alpine basin located near Pemberton, British Columbia -demonstrated that a layer which is either water repellent or has only a limited affinity for water is present at most vegetated sites. The layer is typically a few centimetres in thickness, and is usually located at or near the top of the profile: it was present only in the zone of accumulation of organic matter. The spatial distribution of the layer did not appear to be related to the distribution of any particular species of plant. Sampling of sub-alpine sites in the Cascade, Selkirk, and Purcell Mountains indicated that such layers are common in the alpine - sub-alpine ecotone of southern British Columbia.
The relationship between ponding depth and infiltration rate was explored through experiments conducted on samples collected near Ash Lake, in Goat Meadows. These samples were chosen for analysis because the repellent layer was in excess of thirty centimetres thick at this site. Infiltration rates remained below 2x10⁻⁹ m/s for all samples, even given ponding depths of up to forty centimetres. Breakthrough of liquid water was not observed, even after one month, which implies that most of the infiltration occurred as vapour transfer.
In order to observe the movement of liquid water through water repellent media, a plexiglas cell was constructed. A synthetic water repellent sand with uniform surface properties was used as the medium. It was found that up to some critical depth, there was no entry of water into the medium. As the ponding depth was increased in steps, the front would advance in steps: it remained stationary between these step-increases in ponding depth. As the front advanced, protuberances or "fingers" began to develop. At some critical ponding depth, a finger would grow without bound. These observations pose a challenge to existing models of infiltration, since it appears that heterogeneity at the scale of individual pores must be invoked to explain them, but it is usually assumed that the properties of a porous medium are continuous at this scale.
The thermodynamics of filling and emptying of pores is considered with emphasis on the effects of pore shape and of variations in the physicochemical properties at the scale of the pore. This thermodynamic analysis provides the conceptual basis for development of a model of infiltration in which pore-scale heterogeneity is preserved. Although it was not developed as such, the model follows the approach of cellular automata, in which local relations between pores or "cells" govern the behaviour of the system. The model replicated the observations of infiltration into synthetic water repellent porous media well: both the halting advance of the front as the ponding depth was increased and the development of fingers were simulated. The fact that such complex behaviour was predicted using only a simple set of physically based rules confirms the power of the approach.Arts, Faculty of
Geography, Department of
Graduate
3
Sorooshian, Soroosh, and Vijai Kumar Gupta. "Improving the Reliability of Compartmental Models: Case of Conceptual Hydrologic Rainfall-Runoff Models." Department of Hydrology and Water Resources, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/614011.
Full text
4
Romanel, Celso 1952. "DYNAMIC SOIL-STRUCTURE INTERACTION IN A LAYERED MEDIUM." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276511.
Full textAbstract:
The most popular method in dynamic soil-structure interaction analysis is the finite element method. The versatility in problems involving different materials and complex geometries is its main advantage, yet FEM can not simulate unbounded domains completely. A hybrid method is proposed in this research, which models the near field (structure and surrounding soil) by finite elements and the far field by a continuum approach. The system is excited by monochromatic body waves (P and SV) propagating with oblique incidence and harmonic time dependence. The far field problem is solved using Thomson-Haskell formulation associated with the delta matrix technique. The soil profile does not contain any soft layer and the layers are assumed to be linearly elastic, isotropic, homogeneous and perfectly bonded at the interfaces. Two-dimensional (in-plane) formulation is considered and the analysis is performed on both k- and o-planes through time and spatial Fourier transforms of the field equations and boundary conditions. (Abstract shortened with permission of author.)
5
Park, Soojin. "Modelling soil-landform continuum on a three-dimensional hillslope." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670238.
Full text
6
Washburne, James Clarke. "A distributed surface temperature and energy balance model of a semi-arid watershed." Diss., The University of Arizona, 1994. http://hdl.handle.net/10150/186800.
Full textAbstract:
A simple model of surface and sub-surface soil temperature was developed at the watershed scale (-100 km²) in a semi-arid rangeland environment. The model consisted of a linear combination of air temperature and net radiation and assumed: (1) topography controls the spatial distribution of net radiation, (2) near-surface air temperature and incoming solar radiation are relatively homogeneous at the watershed scale and are available from ground stations and (3) soil moisture dominates transient soil thermal property variability. Multiplicative constants were defined to account for clear sky diffuse radiation, soil thermal inertia, an initially fixed ratio between soil heat flux and net radiation and exponential attenuation of solar radiation through a partial canopy. The surface temperature can optionally be adjusted for temperature and emissivity differences between mixed bare soil and vegetation canopies. Model development stressed physical simplicity and commonly available spatial and temporal data sets. Slowly varying surface characteristics, such as albedo, vegetation density and topography were derived from a series of Landsat TM images and a 7.5" USGS digital elevation model at a spatial resolution of 30 m. Diurnally variable atmospheric parameters were derived from a pair of ground meteorological stations using 30-60 min averages. One site was used to drive the model, the other served as a control to estimate model error. Data collected as part of the Monsoon '90 and WG '92 field experiments over the ARS Walnut Gulch Experimental Watershed in SE Arizona were used to validate and test the model. Point, transect and spatially distributed values of modeled surface temperature were compared with synchronous ground, aircraft and satellite thermal measurements. There was little difference between ground and aircraft measurements of surface reflectance and temperature which makes aircraft transects the preferred method to "ground truth" satellite observations. Mid-morning modeled surface temperatures were within 2° C of observed values at all but satellite scales, where atmospheric water vapor corrections complicate the determination of accurate temperatures. The utility of satellite thermal measurements and models to study various ground phenomena (e.g. soil thermal inertia and surface energy balance) were investigated. Soil moisture anomalies were detectable, but were more likely associated with average near-surface soil moisture levels than individual storm footprints.
7
Mtundu, Nangantani Davies Godfrey. "The Stochastic Behavior of Soil Moisture and Its Role in Catchment Response Models." PDXScholar, 1987. https://pdxscholar.library.pdx.edu/open_access_etds/527.
Full textAbstract:
The object of current efforts at investigating catchment response is to derive a physically based stochastic model of the watershed. Recent studies have, however, indicated that a limiting factor in deriving such models is the dependence of hydrologic response on initial soil moisture. The dependence affects the distributions and moments of the hydrological processes being investigated. A stochastic model of soil moisture dynamics is developed in the form of a pair of stochastic differential equations (SDE's) of the Ito type. The sources of stochasticity are linked to the random inputs of rainfall and evapotranspiration (ET). One of the SDE's describes the "surplus" case, in which sufficient infiltration always occurs to allow for moisture depletion by the processes of drainage through and ET out of the root zone. The other SDE represents the "deficit" case, in which lack of adequate moisture leads only to an ET-controlled depletion process. Sample functions and moments of moisture evolution are obtained from the SDE's. From the general model of soil moisture, a specific model of initial soil moisture (the moisture at the beginning of a rainstorm event) is developed and its moments are derived. Furthermore, the probability distribution of initial moisture is postulated to permit the assessment of how initial moisture affects the estimation of hydrologic response. The moisture dynamics model reveals that the stochastic properties of moisture ae sensitive to initial conditions in the watershed only for less permeable soils under the "surplus" state but are practically insensitive to such conditions for more permeable soils. The stochastic properties are also less sensitive to initial conditions for all soil types whenever under the "deficit" state. These results suggest that hydrologic processes, such as precipitation excess and infiltration, depend on initial moisture only in regions where the soils are generally less permeable and where the climate tends to sustain a "wet" environment, whereas in arid or semi-arid regions, such processes would not depend on initial moisture. These conclusions imply that, in arid regions, an effective value of initial moisture such as the mean can be used to estimate the properties of the hydrologic processes, whereas in "wet" environments, more accurate values of the properties must be "weighted" based on the probability distribution of initial soil moisture.
8
Musa, Zulkarnain 1964. "An accelerated conjugate direction procedure for slope stability analysis." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276912.
Full textAbstract:
CSLIP2 (De Natale, 1987) is the only slope stability program that utilizes a "direction set" optimization routine in its search for the minimum safety factor. However, CSLIP2 which employs Powell's Conjugate Direction Method permits only the horizontal and vertical directions (x and y) to be used as the initial direction set. The efficiency of the existing search routine is improved by replacing the x-y coordinate directions with initial directions that are parallel to and perpendicular to the principal axis of the safety factor contours.
9
Romanel, Celso. "A global-local approach for dynamic soil-structure interaction analysis of deeply embedded structures in a layered medium." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184762.
Full textAbstract:
The most popular method for dynamic soil-structure interaction analysis is the finite element method. The versatility in problems involving different materials and complex geometries is its main advantage, yet the FEM can not simulate unbounded domains completely. Several schemes have been proposed to overcome this shortcoming, such as the use of either imperfect or perfect transmitting boundaries, infinite elements and hybrid techniques. However, most of them were derived on the assumption that the soil mass can be represented as a homogeneous material despite the fact that stratified soil deposits are a common occurrence in nature. A hybrid method is proposed in this research for soil-structure interaction analysis in the frequency domain involving a multilayered linear elastic half-space. The near field region (structure and a portion of soil surrounding it) is modeled by finite elements while the far field formulation is obtained through the classical wave propagation theory based on the assumption that the actual scattered wave fields can be represented by a set of line sources. Traction reciprocity between the two regions is satisfied exactly, while the displacement continuity across the common interface is enforced in a least-squares sense. The two-dimensional system is excited by harmonic body waves (P and SV) propagating with oblique incidence. The structure can be considered either on the surface or deeply embedded in the multilayered half-space. Analytic solutions for the far field domain is obtained through the combined response of four simple problems that take into account the overall effects of the incident, reflected and scattered wave fields. The delta matrix technique is employed in order to eliminate the loss of precision problem associated with the Thomson-Haskell matrix method in its original form. Special numerical schemes are used to transform the solution from the κ- into the ω-plane due to the presence of poles on the path of integration. The few numerical examples studied in this research validate the proposed hybrid technique, but the relatively high computational cost required for evaluation of the Green's functions is still a serious drawback. Some suggestions are made to minimize the problem as well as to extend this technique to cases involving material attenuation and forced vibrations.
10
Sande, Leif Andrew. "Experimental Studies on Infiltration/Soil-Water Movement Processes and Green-AMPT Modeling." Thesis, North Dakota State University, 2011. https://hdl.handle.net/10365/29329.
Full textAbstract:
Experimental studies on infiltration/soil-water movement processes are vital to
better understanding movement of soil-water in the vadose zone. The objective of this
experimental research was to investigate infiltration/soil-water movement processes
utilizing laboratory experiments and computer modeling. Small scale laboratory soil box
infiltration experiments were conducted and utilized for the improved parameterization of
the Green-Ampt (GA) saturated moisture content parameter to produce an effective
moisture content parameter (Be) for utilization in a modified GA model. By incorporating ?e
values into GA modeling, modeling results showed greatly improved wetting front
prediction across different soil conditions. A new soil packing method was proposed for
replicating complex microtopographical surfaces with uniform bulk densities in laboratory
soil box experiments which proved efficient and effective at accomplishing both objectives.
A rainfall simulator and an instantaneous-profile laser scanner were used to simulate
rainfall and quantify surface microtopography for experiments. The results clearly show the
effect of microtopography on infiltration and soil-water movement characteristics. This
offers valuable insight into infiltration/soil-water movement processes as affected by
different soil and surface microtopographic conditions.National Science Foundation (Grant No. EAR-0907588)
Books on the topic "Soil temperature – Mathematical models"
1
A, Albini F., and Intermountain Research Station (Ogden, Utah), eds. Models for fire-driven heat and moisture transport in soils. Ogden, UT: U.S. Dept. of Agriculture, Forest Service, Intermountain Research Station, 1996.
Find full text
2
Kowalczyk, E. A. A soil-canopy scheme for use in a numerical model of the atmosphere - 1D stand alone model. Australia: CSIRO, 1991.
Find full text
3
Kowalczyk, E. A. A soil-canopy scheme for use in a numerical model of the atmosphere - 1D stand alone model. Australia: CSIRO, 1991.
Find full text
4
Kowalczyk, E. A. Implementation of a soil-canopy scheme into the CSIRO GCM - regional aspects of the model response. [Melbourne]: Commonwealth Scientific and Industrial Research Organization, 1994.
Find full text
5
Gori︠a︡ev, V. E. Agrofizicheskie osnovy i metody regulirovanii︠a︡ gidrotermicheskogo rezhima pochv: Na primere Altaĭskogo krai︠a︡. Novosibirsk: Izd-vo Sibirskogo otd-nii︠a︡ Rossiĭskoĭ akademii nauk, 2003.
Find full text
6
Hwang, Soo-Jin. The effects of soil moisture on the energy balance at the bare soil surface. Tsukuba, Japan: Environmental Research Center, University of Tsukuba, 1995.
Find full text
7
Lapham, Wayne W. Use of temperature profiles beneath streams to determine rates of vertical ground-water flow and vertical hydraulic conductivity. Washington, DC: Dept. of the Interior, 1989.
Find full text
8
Lapham, Wayne W. Use of temperature profiles beneath streams to determine rates of vertical ground-water flow and vertical hydraulic conductivity. Washington: U.S. G.P.O., 1989.
Find full text
9
LeCain, Gary D. Use of temperature, pressure, and water potential data to estimate infiltration and monitor percolation in Pagany Wash associated with the winter of 1997-98 El Niño precipitation, Yucca Mountain, Nevada. Denver, Colo. (Box 25046, mail stop 421, Denver Federal Center, Denver 80225-0046): U.S. Dept. of the Interior, U.S. Geological Survey, 2001.
Find full text
10
LeCain, Gary D. Use of temperature, pressure, and water potential data to estimate infiltration and monitor percolation in Pagany Wash associated with the winter of 1997-98 El Niño precipitation, Yucca Mountain, Nevada. Denver, Colo: U.S. Dept. of the Interior, U.S. Geological Survey, 2002.
Find full textBook chapters on the topic "Soil temperature – Mathematical models"
1
Mutandanyi, Tshanduko, and Abdon Atangana. "Modeling Soil Moisture Flow." In Mathematical Analysis of Groundwater Flow Models, 319–52. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003266266-19.
Full text
2
Kirillov, V. V., and R. D. Shelkhovskoi. "Mathematical Models of Low-Temperature Gas Generator." In Proceedings of the 4th International Conference on Industrial Engineering, 47–55. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-95630-5_5.
Full text
3
Schneider, W., A. Baermann, P. Döll, and W. Neumann. "Solute Transport in Holocene Marsh Sediments — Experiments and Mathematical Models —." In Contaminated Soil ’90, 425–26. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-011-3270-1_93.
Full text
4
Thoma, E., I. X. Tsiros, S. Lykoudis, and B. E. Psiloglou. "Applications of Semi-Analytical Models for Estimating Soil Temperature." In Advances in Meteorology, Climatology and Atmospheric Physics, 757–63. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-29172-2_107.
Full text
5
Myeko, Palesa, and Abdon Atangana. "Modeling the Diffusion of Chemical Contamination in Soil with Non-Conventional Differential Operators." In Mathematical Analysis of Groundwater Flow Models, 459–88. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003266266-24.
Full text
6
Awrejcewicz, Jan, Anton V. Krysko, Maxim V. Zhigalov, and Vadim A. Krysko. "Mathematical Models of Functionally Graded Beams in Temperature Field." In Advanced Structured Materials, 197–294. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-55993-9_7.
Full text
7
Sillers, W. Scott, Delwyn G. Fredlund, and Noshin Zakerzadeh. "Mathematical attributes of some soil—water characteristic curve models." In Unsaturated Soil Concepts and Their Application in Geotechnical Practice, 243–83. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-015-9775-3_3.
Full text
8
Zouine, M., M. Akhsassi, N. Erraissi, N. Aarich, A. Bennouna, M. Raoufi, and A. Outzourhit. "Mathematical Models Calculating PV Module Temperature Using Weather Data: Experimental Study." In Lecture Notes in Electrical Engineering, 630–39. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-1405-6_72.
Full text
9
Awrejcewicz, Jan, Anton V. Krysko, Maxim V. Zhigalov, and Vadim A. Krysko. "Mathematical Models of Micro- and Nano-cylindrical Panels in Temperature Field." In Advanced Structured Materials, 131–95. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-55993-9_6.
Full text
10
Krysko, Vadim A., Jan Awrejcewicz, Maxim V. Zhigalov, Valeriy F. Kirichenko, and Anton V. Krysko. "Mathematical Models of Multilayer Flexible Orthotropic Shells Under a Temperature Field." In Advances in Mechanics and Mathematics, 331–421. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-04714-6_6.
Full textConference papers on the topic "Soil temperature – Mathematical models"
1
Yuan, Qing, Zhiming Wu, Wang Li, Bo Yu, and Changchun Wu. "Comparative Study on Atmospheric Temperature Models for the Buried Hot Oil Pipeline." In 2018 12th International Pipeline Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/ipc2018-78451.
Full textAbstract:
In previous studies, the atmospheric temperature was generally assumed to be constant during a period (commonly a month) for the numerical simulation on the buried hot oil pipeline. The rationality of this assumption is controversial due to the absence of quantitative results, and thus it needs to be further verified or investigated to make atmospheric temperature approximation more convincing. In this study, based on the changing trend of actual atmospheric temperature, three mathematical models are established and their expressions are presented according to different approximations. And the relationships among these three expressions are obtained by utilizing mathematical derivation. On the basis of three atmospheric temperature models, the weakly unsteady single oil transportation and strongly unsteady batch transportation are numerically simulated, respectively. According to numerical results, the oil temperature at the pipeline ending point and the soil temperature field are compared for these three models. In order to make comparisons more convincing, the influences of the physical properties of crude oil, operation parameters, pipeline parameters and pipeline environments on the deviations of numerical results are compared and analyzed. Finally, based on all comparisons on the deviations of numerical results, the conclusions are drawn, which can provide beneficial reference for the choice of atmospheric temperature models in future numerical simulation study on the buried hot oil pipeline.
2
CÂRDEI, Petru, and Dragoș MANEA. "MATHEMATICAL MODEL FOR THE HEAT EXCHANGE OF GREENHOUSE AND SOLARIUM SOIL IN THE PLANT ROOT AREA." In RURAL DEVELOPMENT. Aleksandras Stulginskis University, 2018. http://dx.doi.org/10.15544/rd.2017.001.
Full textAbstract:
This paper proposes a structural mathematical model of heat exchange into the soil of a solarium. The model investigates the possibility of a rational choice of the cooling water transit time through the pipeline network located in the plant root area. Also, the size of the cooled root area is roughly determined, according to the temperature of the cooling fluid. At the same time, the model provides information on the degree of soil cooling, meaning the ratio between the average soil temperature in the cooled root area and a reference temperature, for example the temperature indicated by a sensor into the soil, at a distance fixed to the root axis. The model considered is a plan one. Geometric is considered a section through the soil, perpendicular to the axis of the pipe carrying the cooling fluid. The soil, the copper pipe and the water are the components of the model. The finite elements for meshing are flat, triangular. This simple model prepares a three-dimensional complex approach and has, as a preparation, a unidimensional model. Obviously, this model provides some start-up indications for achieving the physical model and content of the process parameter set. After its realization, the physical model will be used for the optimal control of the cooling process in the radicular area, but also for the validation and the improvement of the theoretical model.
3
Ebrahimnia Bajestan, Ehsan, Bassam Saad, and Mohammad Arjmand. "A Practical Approach for Determining Minimum Design Metal Temperature (MDMT) of Transmission Gas Pipelines." In ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-73117.
Full textAbstract:
Abstract Gas transmission pipes are required to have sufficient material toughness at their minimum working temperature, (here, called Minimum Design Metal Temperature, MDMT) to avoid brittle fracture. This paper proposes a new practical approach in predicting the MDMT for buried natural gas transmission pipes. This approach is based on a thermal-hydraulic mathematical model to simulate the conjugate heat transfer through the pipe metal, the gas flow inside the pipe, the soil medium surrounding it, and ambient. For the gas flow inside the pipe, a 1D thermal-hydraulic model was utilized to simulate the convective heat transfer, Joule-Thomson effect, and heating of the gas due to pipe wall friction. Using computational simulations in conjunction with regression analyses, a simplified analytical model was developed to predict the temperature field in the surrounding soil for the parameter ranges of interest, including time-varying ambient air temperature. This model was then incorporated as a boundary condition in the 1D thermal-hydraulic gas flow model above to reflect the thermal interaction among the ambient air temperature, soil medium, pipe metal, and the gas flow inside the pipe. Based on the results, daily average ambient temperature data results in the same soil temperature as the hourly data. The initial soil temperature distribution also affects MDMT prediction. The model has been successfully validated against numerical analysis studies in the literature. The proposed approach can replace the transient computational fluid dynamics (CFD) simulation for practical MDMT prediction in pipelines.
4
Chen, Wei, and Wei Liu. "Numerical and Experimental Analysis of Convection Heat Transfer in a Lean-To Type Greenhouse." In ASME 2004 International Solar Energy Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/isec2004-65009.
Full textAbstract:
In this paper, heat transfer and flow in a lean-to passive solar greenhouse has been studied. A mathematical model based on energy equilibrium and a one-dimensional mathematical model for the unsaturated porous medium have been founded and developed to predict the temperature and moisture content in soil and the enclosed air temperature in the greenhouse. On the condition that plant and massive wall is neglected, the air is mainly heated by the soil surface in the greenhouse, which absorbs the incident solar radiation. With increase in depth, the variation of the temperature and moisture content in soil decreases on account of ambient, and the appearance of the peak temperature in soil postpones. Solar irradiation absorber, heat storage and insulation are the main effects of the north massive wall on greenhouse, which is influenced by the structure and the material. The specific heat capacity and thermal conductivity of wall material have a remarkable effect on the north wall temperature. The build-up north wall with thermal insulation material may be chosen for greenhouse. The temperature distribution and gas flow in greenhouse is influenced by the cover material of the inside surface of the north wall. All results should be taken into account for a better design and run of a greenhouse.
5
Chen, Lei, Junjie Gao, Gang Liu, and Cheng Chen. "A Simplified Simulation Model for Buried Hot Oil Pipeline Temperature Field During Shutdown." In 2018 12th International Pipeline Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/ipc2018-78812.
Full textAbstract:
The temperature drop of waxy crude oil after a shutdown is the basic premise for restarting relative mechanical calculation. However, computational accuracy has been paid much more attention excessively in the relevant techniques proposed in the previous researches for this calculation but ignoring the practicability of the calculation results. In this paper a new mathematical model is established for a buried hot crude oil pipeline during shutdown with the simplified complex physical process of oil cooling process reasonably, in which the heat transfer mode of crude oil is divided into pure convection heat transfer and pure heat conduction with stagnation point temperature neglecting the difference of radial temperature. The quasi periodic property theory of soil temperature field is referenced to be as the boundary condition for the thermal influence region. A numerical solution with a structured grid and an analytical solution under polar coordinate are respectively applied for the soil region and other regions including pipe wall, wax layer and insulation layer. The finite volume method is adopted to discretize the heat transfer control equation at the same time the boundary conditions are treated by the additional source term method. The simulation results of the new model are verified by a temperature field tested experiment, especially analyzing the temperature deviation between the simulation and the equivalent mean value of actual oil temperature. At last the effect of buried depth of pipeline on the temperature profiles during normal operation and the temperature drop process of crude oil were investigated based on the simplified model.
6
Filimonov, Mikhail Yu, and Nataliia A. Vaganova. "Simulation of Thermal Fields in the Permafrost With Seasonal Cooling Devices." In 2012 9th International Pipeline Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ipc2012-90287.
Full textAbstract:
A new mathematical model of heat distribution in permafrost soils is considered taking into account different climatic and physical factors. The first group of factors includes consideration of solar radiation, seasonal changes of air temperature, leading to periodic thawing (freezing) of soil, and possible snow layers. The second group of factors is the heterogeneity of the soil, the presence of a number of piles, or foundation structures, seasonal cooling devices. Seasonal cooling devices are vapor-fluid devices consisting of a hermetically sealed and seasoned with coolant, metal pipe with diameter 57 mm, length up to 10 meters or more, consisting of aerial parts (condenser fins) up to 2.5 meters and an underground part. These devices operate without external power sources only by the laws of physics. Taking into account these factors leads to solution of three-dimensional quasilinear heat distribution equation (quasi-linear equation due to the dependence of the thermophysical parameters on temperature) of the Stefan problem in a rectangular parallelepiped, but also with a nonlinear boundary condition at the soil surface associated with solar radiation. It is assumed that the lateral faces of the computational domain are insulated and are chosen sufficiently far from the location of engineering structures, and a computational grid of large dimension to be used, with adaptation to the heat (cold) sources. Software product is designed for numerical simulation of thermal fields in permafrost and melted soil, taking into account thermal diffusion properties of the soil and heat exchange between the soil and air, including also due to heat loss by radiation. The paper is devoted to the results of numerical simulations carried out for the project work in several oil and gas fields in Russia, located in the permafrost zone.
7
Egu, Daniel Ikechukwu, Anthony John Ilozobhie, and Justice Osuala. "Cogent Prognostics of Mellowed Wax Ubiety Temperature Modeling of Nigerian Crude Oil." In SPE Nigeria Annual International Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/212026-ms.
Full textAbstract:
Abstract Cogent prognostic of mellowed wax ubiety temperature of crude oil in the field of study has been a major challenge the four wells were commissioned in 2002. This may be due to the wrong application of conventional techniques of perhaps non- effective wax inhibitors, pipeline insulations, pipeline cleaning, heating and pigging capacity issues, higher cost maintenance and monitoring. The current wax models have numerous short comings in the estimation of simple modification of complex classical wax models and to accurately describe percentage wax solid weights and solid phase trends at controlled temperatures and pressures. Simulation constraints of available crude oil wax simulators are incapacitated by their inconsistent ability to delineate wax appearance patterns at different temperatures with minute time. Non validation of data used with field data makes wax prediction and management difficult. The aim of this study is to compare laboratory results with simulated wax appearance models using the Won original, Won with Sol Params, Chung modified and Pedersen wax models and predict new simplified models from a Field in the Niger Delta. The objectives are to develop improved correlations from the cumulative models for the percentage (%) wax amount (weight) and solid phases at different temperatures using laboratory and mathematically simulated results. To compare results of modified and conventional wax models and technically describing the patterns identified. Four samples of waxy crudes in the Niger Delta were collected intermittently for a period of 16 weeks after pigging. They were characterized, tested and cooled. The wax deposit was scrapped and solid weights and phases were measured at a range of 40 – 100°F and controlled pressure range of 250 to 1200psi. This was used as the controlled data and inputted into the PVTP-IPM mathematical simulator. Results of this modified wax model for solid phase gave Mod Sph = -0.0704T + 6.7536 with R2 = 0.9736. This shows similar pattern (inverse straight line) with the won with the Sol Params and Won original but with high variance from the Pederson wax model due to its higher pour point. Results of Modified Wax model for Solid weight gave Mod Swt = -0.2899T + 28.293 with R2 = 0.987 gave similar patterns greater divergence of the Pederson model. This disparity may be due parameters in the model and wax types. Comparison of the model gave good matches with appreciable square of regressions. Field results showed improved wax predictions, crude oil flow, monitoring and management. The validity of this model is however hinged on the temperature and pressures with PVT data applied while lab results are in consonant with the model results. Wax challenges must be thoroughly examined and the linearization modeling pattern approach embraced and perhaps should deviate from a scholarly exercise but an industry energizer which is strongly recommended as a technical guide to predict, control, interpret and effectively manage wax precipitations.
8
Domnin, Dmitry, Dmitry Domnin, Boris Chubarenko, Boris Chubarenko, Rene Capell, and Rene Capell. "MATHEMATICAL MODELING OF NUTRIENT LOADING FROM SMALL CATCHMENTS OF THE VISTULA LAGOON." In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.31519/conferencearticle_5b1b93dfde6248.02952871.
Full textAbstract:
Vistula Lagoon as a part of the coastal zone translates nutrient load from catchment to the Baltic Sea. Catchments of the Primorskaya River (small settlements, mostly agricultural area, 120 km2) and Banówka-Mamonovka River (transboundary catchment between Russia and Poland, relatively big settlements, food production enterprises, agricultural activity, 490 km2) were selected as test ones for the Vistula Lagoon catchment (23 870 km2). Assessment of the retention of total nitrogen and phosphorus in the catchment and the transformation of nutrient load from anthropogenic sources while passing the catchment were studied by using open source numerical modeling tools. Initial data comprises the geomorphic characteristics, river net data, information on land use and nutrient point sources, time series of temperature, precipitation. Runoff was simulated by hydrological model HYPE considering the evaporation and infiltration into the soil. Retention and transport of nutrients were accessed using the model FyrisNP. Source apportionment was made for the nutrient load discharging from both catchments to the Vistula Lagoon. The greatest amount of nutrients in final discharge is coming from the arable land (50-80%), point sources constitute a smaller proportion (5-30%). The results will be used to obtain the first order approximation of the nutrient load from other small rivers of the Vistula Lagoon catchment and from the biggest river in the area, the Pregolya River (15 300 km2) by analogy.
9
Domnin, Dmitry, Dmitry Domnin, Boris Chubarenko, Boris Chubarenko, Rene Capell, and Rene Capell. "MATHEMATICAL MODELING OF NUTRIENT LOADING FROM SMALL CATCHMENTS OF THE VISTULA LAGOON." In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.21610/conferencearticle_58b431754b7a5.
Full textAbstract:
Vistula Lagoon as a part of the coastal zone translates nutrient load from catchment to the Baltic Sea. Catchments of the Primorskaya River (small settlements, mostly agricultural area, 120 km2) and Banówka-Mamonovka River (transboundary catchment between Russia and Poland, relatively big settlements, food production enterprises, agricultural activity, 490 km2) were selected as test ones for the Vistula Lagoon catchment (23 870 km2). Assessment of the retention of total nitrogen and phosphorus in the catchment and the transformation of nutrient load from anthropogenic sources while passing the catchment were studied by using open source numerical modeling tools. Initial data comprises the geomorphic characteristics, river net data, information on land use and nutrient point sources, time series of temperature, precipitation. Runoff was simulated by hydrological model HYPE considering the evaporation and infiltration into the soil. Retention and transport of nutrients were accessed using the model FyrisNP. Source apportionment was made for the nutrient load discharging from both catchments to the Vistula Lagoon. The greatest amount of nutrients in final discharge is coming from the arable land (50-80%), point sources constitute a smaller proportion (5-30%). The results will be used to obtain the first order approximation of the nutrient load from other small rivers of the Vistula Lagoon catchment and from the biggest river in the area, the Pregolya River (15 300 km2) by analogy.
10
Ghaith, Fadi A., and Fadi J. Alsouda. "Enhancing the Performance of the Building’s Vapor Compression Air Cooling System Using Earth-Air Heat Exchanger." In ASME 2017 11th International Conference on Energy Sustainability collocated with the ASME 2017 Power Conference Joint With ICOPE-17, the ASME 2017 15th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2017 Nuclear Forum. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/es2017-3200.
Full textAbstract:
This paper aims to evaluate the thermal performance and feasibility of integrating the Earth-Air Heat Exchanger (EAHE) with the building’s vapor compression air cooling system. In the proposed system, the ambient air is forced by an axial fan through an EAHE buried at a certain depth below the ground surface. EAHE uses the subsoil low temperature and soil thermal properties to reduce the air temperature. The outlet air from the EAHE was used for the purpose of cooling the condenser of the vapor compression cycle (VCC) to enhance its coefficient of performance (COP). The potential enhancement on the COP was investigated for two different refrigerants (i.e. R-22 and R410a) cooling systems. A mathematical model was developed to estimate the underground soil temperature at different depths and the corresponding outlet air temperature of EAHE was calculated. The obtained results showed that the soil temperature in Dubai at 4 meters depth is about 27°C and remains relatively constant across the year. In order to estimate the effect of using EAHE on the performance of the VCC system, a sample villa project was selected as a case study. The obtained results showed that EAHE system contributed efficiently to the COP of the VCC with an overall increase of 47 % and 49 % for R-22 and R410a cycles, respectively. Moreover, the calculated values were validated against Cycle_D simulation model and showed good agreement with a maximum deviation of 5%. The payback period for this project was found to be around two years while the expected life time is about 10 years which makes it an attractive investment.
Reports on the topic "Soil temperature – Mathematical models"
1
Clausen, Jay, Christopher Felt, Michael Musty, Vuong Truong, Susan Frankenstein, Anna Wagner, Rosa Affleck, Steven Peckham, and Christopher Williams. Modernizing environmental signature physics for target detection—Phase 3. Engineer Research and Development Center (U.S.), March 2022. http://dx.doi.org/10.21079/11681/43442.
Full textAbstract:
The present effort (Phase 3) builds on our previously published prior efforts (Phases 1 and 2), which examined methods of determining the probability of detection and false alarm rates using thermal infrared for buried object detection. Environmental phenomenological effects are often represented in weather forecasts in a relatively coarse, hourly resolution, which introduces concerns such as exclusion or misrepresentation of ephemera or lags in timing when using this data as an input for the Army’s Tactical Assault Kit software system. Additionally, the direct application of observed temperature data with weather model data may not be the best approach because metadata associated with the observations are not included. As a result, there is a need to explore mathematical methods such as Bayesian statistics to incorporate observations into models. To better address this concern, the initial analysis in Phase 2 data is expanded in this report to include (1) multivariate analyses for detecting objects in soil, (2) a moving box analysis of object visibility with alternative methods for converting FLIR radiance values to thermal temperature values, (3) a calibrated thermal model of soil temperature using thermal IR imagery, and (4) a simple classifier method for automating buried object detection.
2
Lieth, J. Heiner, Michael Raviv, and David W. Burger. Effects of root zone temperature, oxygen concentration, and moisture content on actual vs. potential growth of greenhouse crops. United States Department of Agriculture, January 2006. http://dx.doi.org/10.32747/2006.7586547.bard.
Full textAbstract:
Soilless crop production in protected cultivation requires optimization of many environmental and plant variables. Variables of the root zone (rhizosphere) have always been difficult to characterize but have been studied extensively. In soilless production the opportunity exists to optimize these variables in relation to crop production. The project objectives were to model the relationship between biomass production and the rhizosphere variables: temperature, dissolved oxygen concentration and water availability by characterizing potential growth and how this translates to actual growth. As part of this we sought to improve of our understanding of root growth and rhizosphere processes by generating data on the effect of rhizosphere water status, temperature and dissolved oxygen on root growth, modeling potential and actual growth and by developing and calibrating models for various physical and chemical properties in soilless production systems. In particular we sought to use calorimetry to identify potential growth of the plants in relation to these rhizosphere variables. While we did experimental work on various crops, our main model system for the mathematical modeling work was greenhouse cut-flower rose production in soil-less cultivation. In support of this, our objective was the development of a Rose crop model. Specific to this project we sought to create submodels for the rhizosphere processes, integrate these into the rose crop simulation model which we had begun developing prior to the start of this project. We also sought to verify and validate any such models and where feasible create tools that growers could be used for production management. We made significant progress with regard to the use of microcalorimetry. At both locations (Israel and US) we demonstrated that specific growth rate for root and flower stem biomass production were sensitive to dissolved oxygen. Our work also identified that it is possible to identify optimal potential growth scenarios and that for greenhouse-grown rose the optimal root zone temperature for potential growth is around 17 C (substantially lower than is common in commercial greenhouses) while flower production growth potential was indifferent to a range as wide as 17-26C in the root zone. We had several set-backs that highlighted to us the fact that work needs to be done to identify when microcalorimetric research relates to instantaneous plant responses to the environment and when it relates to plant acclimation. One outcome of this research has been our determination that irrigation technology in soilless production systems needs to explicitly include optimization of oxygen in the root zone. Simply structuring the root zone to be “well aerated” is not the most optimal approach, but rather a minimum level. Our future work will focus on implementing direct control over dissolved oxygen in the root zone of soilless production systems.
3
VanderGheynst, Jean, Michael Raviv, Jim Stapleton, and Dror Minz. Effect of Combined Solarization and in Solum Compost Decomposition on Soil Health. United States Department of Agriculture, October 2013. http://dx.doi.org/10.32747/2013.7594388.bard.
Full textAbstract:
In soil solarization, moist soil is covered with a transparent plastic film, resulting in passive solar heating which inactivates soil-borne pathogen/weed propagules. Although solarization is an effective alternative to soil fumigation and chemical pesticide application, it is not widely used due to its long duration, which coincides with the growing season of some crops, thereby causing a loss of income. The basis of this project was that solarization of amended soil would be utilized more widely if growers could adopt the practice without losing production. In this research we examined three factors expected to contribute to greater utilization of solarization: 1) investigation of techniques that increase soil temperature, thereby reducing the time required for solarization; 2) development and validation of predictive soil heating models to enable informed decisions regarding soil and solarization management that accommodate the crop production cycle, and 3) elucidation of the contributions of microbial activity and microbial community structure to soil heating during solarization. Laboratory studies and a field trial were performed to determine heat generation in soil amended with compost during solarization. Respiration was measured in amended soil samples prior to and following solarization as a function of soil depth. Additionally, phytotoxicity was estimated through measurement of germination and early growth of lettuce seedlings in greenhouse assays, and samples were subjected to 16S ribosomal RNA gene sequencing to characterize microbial communities. Amendment of soil with 10% (g/g) compost containing 16.9 mg CO2/g dry weight organic carbon resulted in soil temperatures that were 2oC to 4oC higher than soil alone. Approximately 85% of total organic carbon within the amended soil was exhausted during 22 days of solarization. There was no significant difference in residual respiration with soil depth down to 17.4 cm. Although freshly amended soil proved highly inhibitory to lettuce seed germination and seedling growth, phytotoxicity was not detected in solarized amended soil after 22 days of field solarization. The sequencing data obtained from field samples revealed similar microbial species richness and evenness in both solarized amended and non-amended soil. However, amendment led to enrichment of a community different from that of non-amended soil after solarization. Moreover, community structure varied by soil depth in solarized soil. Coupled with temperature data from soil during solarization, community data highlighted how thermal gradients in soil influence community structure and indicated microorganisms that may contribute to increased soil heating during solarization. Reliable predictive tools are necessary to characterize the solarization process and to minimize the opportunity cost incurred by farmers due to growing season abbreviation, however, current models do not accurately predict temperatures for soils with internal heat generation associated with the microbial breakdown of the soil amendment. To address the need for a more robust model, a first-order source term was developed to model the internal heat source during amended soil solarization. This source term was then incorporated into an existing “soil only” model and validated against data collected from amended soil field trials. The expanded model outperformed both the existing stable-soil model and a constant source term model, predicting daily peak temperatures to within 0.1°C during the critical first week of solarization. Overall the results suggest that amendment of soil with compost prior to solarization may be of value in agricultural soil disinfestations operations, however additional work is needed to determine the effects of soil type and organic matter source on efficacy. Furthermore, models can be developed to predict soil temperature during solarization, however, additional work is needed to couple heat transfer models with pathogen and weed inactivation models to better estimate solarization duration necessary for disinfestation.
4
Friedman, Shmuel, Jon Wraith, and Dani Or. Geometrical Considerations and Interfacial Processes Affecting Electromagnetic Measurement of Soil Water Content by TDR and Remote Sensing Methods. United States Department of Agriculture, 2002. http://dx.doi.org/10.32747/2002.7580679.bard.
Full textAbstract:
Time Domain Reflectometry (TDR) and other in-situ and remote sensing dielectric methods for determining the soil water content had become standard in both research and practice in the last two decades. Limitations of existing dielectric methods in some soils, and introduction of new agricultural measurement devices or approaches based on soil dielectric properties mandate improved understanding of the relationship between the measured effective permittivity (dielectric constant) and the soil water content. Mounting evidence indicates that consideration must be given not only to the volume fractions of soil constituents, as most mixing models assume, but also to soil attributes and ambient temperature in order to reduce errors in interpreting measured effective permittivities. The major objective of the present research project was to investigate the effects of the soil geometrical attributes and interfacial processes (bound water) on the effective permittivity of the soil, and to develop a theoretical frame for improved, soil-specific effective permittivity- water content calibration curves, which are based on easily attainable soil properties. After initializing the experimental investigation of the effective permittivity - water content relationship, we realized that the first step for water content determination by the Time Domain Reflectometry (TDR) method, namely, the TDR measurement of the soil effective permittivity still requires standardization and improvement, and we also made more efforts than originally planned towards this objective. The findings of the BARD project, related to these two consequential steps involved in TDR measurement of the soil water content, are expected to improve the accuracy of soil water content determination by existing in-situ and remote sensing dielectric methods and to help evaluate new water content sensors based on soil electrical properties. A more precise water content determination is expected to result in reduced irrigation levels, a matter which is beneficial first to American and Israeli farmers, and also to hydrologists and environmentalists dealing with production and assessment of contamination hazards of this progressively more precious natural resource. The improved understanding of the way the soil geometrical attributes affect its effective permittivity is expected to contribute to our understanding and predicting capability of other, related soil transport properties such as electrical and thermal conductivity, and diffusion coefficients of solutes and gas molecules. In addition, to the originally planned research activities we also investigated other related problems and made many contributions of short and longer terms benefits. These efforts include: Developing a method and a special TDR probe for using TDR systems to determine also the soil's matric potential; Developing a methodology for utilizing the thermodielectric effect, namely, the variation of the soil's effective permittivity with temperature, to evaluate its specific surface area; Developing a simple method for characterizing particle shape by measuring the repose angle of a granular material avalanching in water; Measurements and characterization of the pore scale, saturation degree - dependent anisotropy factor for electrical and hydraulic conductivities; Studying the dielectric properties of cereal grains towards improved determination of their water content. A reliable evaluation of the soil textural attributes (e.g. the specific surface area mentioned above) and its water content is essential for intensive irrigation and fertilization processes and within extensive precision agriculture management. The findings of the present research project are expected to improve the determination of cereal grain water content by on-line dielectric methods. A precise evaluation of grain water content is essential for pricing and evaluation of drying-before-storage requirements, issues involving energy savings and commercial aspects of major economic importance to the American agriculture. The results and methodologies developed within the above mentioned side studies are expected to be beneficial to also other industrial and environmental practices requiring the water content determination and characterization of granular materials.
5
Lohne, Arild, Arne Stavland, Siv Marie Åsen, Olav Aursjø, and Aksel Hiorth. Recommended polymer workflow: Interpretation and parameter identification. University of Stavanger, November 2021. http://dx.doi.org/10.31265/usps.202.
Full textAbstract:
Injecting a polymer solution into a porous medium significantly increases the modeling complexity, compared to model a polymer bulk solution. Even if the polymer solution is injected at a constant rate into the porous medium, the polymers experience different flow regimes in each pore and pore throat. The main challenge is to assign a macroscopic porous media “viscosity” to the fluid which can be used in Darcy law to get the correct relationship between the injection rate and pressure drop. One can achieve this by simply tabulating experimental results (e.g., injection rate vs pressure drop). The challenge with the tabulated approach is that it requires a huge experimental database to tabulate all kind of possible situations that might occur in a reservoir (e.g., changing temperature, salinity, flooding history, permeability, porosity, wettability etc.). The approach presented in this report is to model the mechanisms and describe them in terms of mathematical models. The mathematical model contains a limited number of parameters that needs to be determined experimentally. Once these parameters are determined, there is in principle no need to perform additional experiments.