Dissertations / Theses: 'Temperature - Mathematics'

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Gebbie, Tim. "Temperature anisotropies: covariant CMB anisotropies and nonlinear corrections." Doctoral thesis, Faculty of Science, 1999. http://hdl.handle.net/11427/30218.

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The questions I ask myself are generally all along the lines of "so where did all this structure come from?". I hoped that work in the CMB and its cosmological implications would give me insight into this. It is an adventure that is still young. I began my PhD with an investigation of some formal aspects of Ehlers-Ellis Relativistic Kinetic Theory in mind { the implications of the truncation conditions found in the exact theory. I ended up trying to calculate CMB anisotropies as an application of this beautiful and somewhat purist formalism. The Ehler-Ellis (1+3) Lagrangian approach to General Relativity (GR) and Relativistic Kinetic Theory (RKT) are apparently not well known nor well used and have only recently begun to show advantages over the more usual ADM and Bardeen perturbative approaches to astrophysical cosmology when combined with the Ellis Bruni perturbation theory.

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Robl, Florian. "On P(φ)_2 interactions at positive temperature." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/31340/.

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The Schwinger functions of the thermal P (φ)2 model on the real line and the vacuum P (φ)2 model on the circle are equal up to interpretation of their time and space coordinates. This is called Nelson symmetry. In the present work this correspondence is exploited to construct and prove results for the thermal P (φ)2 model. The results are existence of the thermal Wightman functions, the relativistic KMS condition, verification of the Wightman axioms and spatial exponential decay. A H ̈lder inequality for general KMS states is proven, employing non-commutative o Lp -spaces. This inequality is key in the proof of the existence of the thermal Wightman functions. For the vacuum P (φ)2 model on the circle a version of the Glimm-Jaffe φ-bound is proven. Furthermore the K ̈ll ́n-Lehmann representation for general vacuum two-point a e functions are proven and general facts about the damping factor are established. The consequences for the damping factor in the thermal case are briefly discussed.

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Cronqvist, Frida. "Interpolation of temperature data for improved weather forecasts." Thesis, KTH, Optimeringslära och systemteori, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-229731.

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To create weather forecasts at the Swedish Meteorological and Hydrological Institute (SMHI), it is needed to interpolate the temperature from the observation stations into a grid with 2.5 km between each point. Since the observed temperatures are known and without error, they should be held fix even after the interpolation. Usually, there is a strong relationship between temperature and elevation which needs to be accounted for in the interpolation method. In this study, regression kriging was investigated and compared to inverse distance weighted interpolation (IDW). Different choices to be made within regression kriging were investigated to optimize the method and the results were evaluated using leave-one-out cross validation for many different sets of data. The result was that regression kriging always had a smaller mean square error than IDW, as long as there were no violation of the required assumptions. If there were, regression kriging can lead to large errors and can therefore not be used. To avoid violating the assumptions, the regression part of regression kriging needs to be accurate enough. This might require more information than only the latitude and longitude coordinates and the elevation, which is what was known in this study.
För att producera väderprognoser på Sveriges Meteorologiska och Hydrologiska Institut (SMHI) krävs det att temperaturerna från mätstationerna interpoleras till ett rutnät med 2.5 km mellan varje punkt. Eftersom de observerade temperaturerna är kända och utan fel ska de hållas fixa även efter interpolationen. Vanligtvis finns det ett starkt samband mellan temperatur och höjd över havet som också ska tas i beaktande i interpolationen. I den här studien undersöktes interpolationsmetoden regressionskriging och jämfördes med inverse distance weighted interpolation (IDW). Olika valmöjligheter inom regressionskrigingen undersöktes för att optimera metoden och resultaten från många olika datamängder evaluerades med hjälp av korsvalidering. Resultatet blev att regressionskriging alltid gav ett mindre genomsnittligt kvadratfel än IDW, så länge antagandena som krävs för metoden var uppfyllda. är de inte det kan regressionskriging leda till stora fel och kan därför inte användas. För att uppfylla dessa antaganden måste regressionsdelen i regressionskriging vara tillräckligt precis, vilket kan kräva mer information än enbart latitud och longitudkoordinater samt höjddata, vilket var den enda kända informationen i denna studie.

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Eckner, Sinziana Maria. "Stochastic Ising Models at Zero Temperature on Various Graphs." Thesis, New York University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3665138.

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In this thesis we study continuous time Markov processes whose state space consists of an assignment of +1 or -1 to each vertex x of a graph G. We will consider two processes, σ( t) and σ'(t), having similar update rules. The process σ(t) starts from an initial spin configuration chosen from a Bernoulli product measure with density θ of +1 spins, and updates the spin at each vertex, σ_x(t), by taking the value of a majority of x's nearest neighbors or else tossing a fair coin in case of a tie. The process σ'( t) starts from an arbitrary initial configuration and evolves according to the same rules as σ(t), except for some vertices which are frozen plus (resp., minus) with density ρ⁺ (resp., & ρ^–) and whose value is not allowed to change. Our results are for when σ(t) evolves on graphs related to homogeneous trees of degree K ≥ 3, such as finite or infinite stacks of such trees, while the process σ'(t) evolves on Z^d, d ≥ 2. We study the long time behavior of these processes and, in the case of σ'(t), the prevalence of vertices that are (eventually) fixed plus or fixed minus or flippers (changing forever). We prove that, if θ is close enough to 1, σ(t) reaches fixation to +1 consensus. For σ'( t) we prove that, if ρ⁺>0 and ρ^– = 0, all vertices end up as fixed plus, while for ρ⁺ >0 and ρ^– very small (compared to ρ⁺), the fixed minus and flippers together do not percolate.

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Hallgren, Christoffer. "Temperature effects on ant activity : Analysis of a mathematical model." Thesis, Uppsala universitet, Analys och tillämpad matematik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-180927.

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Elama, Ameh Josephine, and Josephine Elanma Ochigbo. "Investigating the simultaneous effect of age and temperature on the population dynamics of female tsetse flies." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/18101.

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Thesis (MSc)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: Age and temperature are two factors that affect mortality in adult tsetse flies. Both are found to be very important, but the simultaneous effect of these factors on the mortality rate have not been studied. This study seeks to address this, with an application to a population of female tsetse, using a model based on partial differential equations. Adult mortality is agedependent and is modelled as the sum of two exponentials, with four parameters (coefficients of each exponential): numerical analysis of a population model with this mortality structure predicts exponential growth. Analysis of each of the parameters through parameter variation shows that two of these parameters control the mortality of the nulliparous (ages 0 − 10 days) flies only while the other two only take care of flies of mature ages. Measurement of the impact of these parameters on the mortality of tsetse of different ages by the normalized forward sensitivity index method is also carried out. This is followed by fitting the model based on the age-dependent mortality along with a constant tsetse birth rate to data representing the catches of female Glossina pallidipes at Rekomitjie Research station, Zimbabwe. Considering a three parameter adult tsetse mortality, parameter analysis shows the effect of one of the parameters to affect the mortality of flies of all ages while a second controls only the mature tsetse flies of reproductive ages. A further analysis resulted in the estimate of these parameters as functions of temperature, thereby leading to the establishment of an age and temperature-dependent adult tsetse mortality. Using data for the daily average temperature records obtained in 1981 on Antelope Island, Lake Kariba, Zimbabwe, daily changes in the pupal duration (adult tsetse birth rate) changes negatively with temperature change. Incorporating this (temperature-dependent ) birth rate into the model, together with the established age and temperature-dependent adult mortality, the adult tsetse population dynamics is explored numerically. The latter model is then fitted to population data of female Glossina morsitans morsitans obtained from the same Island and for the same period as used for the temperature data. The data suggests peak tsetse population to be in the month of July and lowest in the month of December. The first quarter of the year is predicted to be most favorable for breeding tsetse while the second, showed a period of stable growth rate and a time of tsetse abundance. In addition, the dynamics with both age and temperature showed a non-uniform daily population growth contrary to that with age effect only. This study has enhanced our understanding of tsetse population dynamics for age and temperature-dependent adult mortality with temperature-dependent pupal duration and suggests the period of tsetse abundance on Antelope Island.
AFRIKAANSE OPSOMMING: Geen opsomming in Afrikaans.

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Nteka, Ioanna. "Positive temperature dynamics on Gelfand-Tsetlin patterns restricted by wall." Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/93408/.

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The thesis focuses on processes on symplectic Gelfand-Tsetlin patterns. In chapter 4, a process with dynamics inspired by the Berele correspondence [Ber86] is presented. It is proved that the shape of the pattern is a Doob h-transform of independent random walks with h given by the symplectic Schur function. This is followed by an extension to a q-weighted version. This randomised version has itself a branching structure and is related to a q-deformation of the so2n+1-Whittaker functions. In chapter 5, we present a fully randomised process. This process q-deforms a process proposed in [WW09]. In chapter 7 we prove the convergence of the q-deformation of the so2n+1-Whittaker functions to the classical so2n+1-Whittaker functions when q → 1. Finally, in chapter 8 we turn our interest to the continuous setting and construct a process on patterns which contains a positive temperature analogue of the Dyson's Brownian motion of type B∕C. The processes obtained are h-transforms of Brownian motions killed at a continuous rate that depends on their distance from the boundary of the Weyl chamber of type B∕C, with h related with the so2n+1-Whittaker functions.

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Zong, Lu. "Temperature-based weather derivatives modeling and contract design in mainland China." Thesis, University of Liverpool, 2015. http://livrepository.liverpool.ac.uk/2017319/.

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In the presented thesis, we build the theoretical framework for the development of temperature-based weather derivatives market in China. Our research is divided into two separate studies due to their different scopes. In the first study, we focus on the determination of the most precise model for temperature-based weather derivative modeling and pricing in China. To achieve this objective, a heuristic comparison of the new stochastic seasonal variation (SSV) model with three established empirical temperature and pricing models, i.e. the Alaton model [1], the CAR model [2] and the Spline model [3] is conducted. Comparison criteria include residual normality, residual auto-correlation function (ACF), Akaike information criterion (AIC), relative errors, and stability of price behaviors. The results show that the SSV model dominates the other three models by providing both a more precise fitting of the temperature process and more stable price behaviors. In the second study, novel forms of temperature indices are proposed and analyzed both on the city level and the climatic zone level, with the aim to provide a contract-selecting scheme that increases the risk management efficiency in the agricultural sector of China. Performances of the newly-introduced indices are investigated via an efficiency test which considers the root mean square loss (RMSL), the value at risk (VaR) and the certainty-equivalent revenues (CERs). According to the results, agricultural risk management on the city scale can be optimized by using the absolute-deviation growth degree-day (GDD) index. On the other hand, it is suggested that climatic zone-based contracts can be more efficient compared with city-based contracts. The recommended contract-selection scheme is to purchase climatic zone-based average GDD contracts in climatic zone II, and to purchase climatic zone-based optimal-weighted GDD contracts in climatic zone I or III.

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Pirc, Alycia Ann. "Modeling Temperature-Sensitive Neural Networks in the Hypothalamus." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306811701.

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Molvalioglu, Orcun. "Interacting-particle algorithm and meta-control of temperature parameter /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/10687.

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Johansson, Tomas. "Reconstruction of flow and temperature from boundary data." Doctoral thesis, Linköping : Univ, 2003. http://www.bibl.liu.se/liupubl/disp/disp2003/tek832s.pdf.

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Htet, Maung Soe. "Airline Error Correction Model and Its Application to Forecast the California Carbon Monoxide, Precipitation, and Air Temperature." Thesis, Southeast Missouri State University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10617045.

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Environmental data such as carbon monoxide (CO), precipitation, air temperature, and traffic have recently drawn the attention of researchers. Several time series models such as Seasonal Autoregressive Integrated Moving Average (SARIMA) and Vector Autoregressive (VAR) models have been applied to forecast CO. A VAR model can study extrinsic and intrinsic variables together but it does not incorporate seasonality. An Airline model is a special case of SARIMA which uses only an intrinsic variable and incorporates seasonality. The purpose of this thesis is to propose a time series model which incorporates seasonality and uses an extrinsic variable to forecast an intrinsic variable. The model is called Airline Error Correction Model (AECM). This thesis uses AECM to forecast CO using traffic, precipitation and air temperature as extrinsic variables. The forecasts using different models of AECM are compared to forecasts using VAR and Airline models. The results of the study show that AECM does a better job on forecasting than VAR and Airline models.

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Tittle, James Alfred. "Ab Initio Studies of High Temperature Pyrolysis Mechanisms in Heterocyclic Nitrogen-Containing Compounds." Digital Commons @ East Tennessee State University, 2000. https://dc.etsu.edu/etd/21.

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The decomposition mechanisms of various coal constituents undergoing pyrolysis are of great concern in environmental circles (especially those coal constituents containing nitrogen). Most methods of burning coal that are efficient involve doing so at high temperatures. This invariably results in a large portion of non-combusting coal being heated to high temperatures also causing pyrolysis of the original coal constituents. The end result of such pyrolysis is the production of a number of noxious gaseous products. If we are to design methods of reducing the amount of toxins that are produced from the industrial use of coal, it is necessary to understand the pyrolysis process mechanistically. Due to the great number of coal constituents, a reasonable approach to such a mechanistic study is to use a simpler model. Pyridine makes an excellent starting model upon which to build. Our study focuses on interpretation of proposed reaction channels from experimental work on pyridine, quinoline and isoquinoline shock-tube decomposition in light of new ab initio energy calculations using Gaussian 98. The pathways thus determined support the proposed pyrolysis mechanisms and agree with experimental evidence obtained from independent groups of researchers performing shock tube pyrolysis.

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McNamara, Joy. "The Effect of Temperature on the Electrical and Optical Properties of p-type GaN." VCU Scholars Compass, 2013. http://scholarscompass.vcu.edu/etd/3049.

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The development of gallium nitride (GaN) light emitting devices has reached extraordinary echelons. As such, the characterization and analysis of the behavior of GaN materials is essential to the advancement of GaN technology. In this thesis, the effect of temperature on the optical and electrical properties of p-type GaN is investigated. The GaN samples used in this work were grown by various methods and studied by Kelvin probe and photoluminescence (PL) techniques. Specifically, the surface photovoltage (SPV) behavior and PL data were analyzed at different temperatures and illumination intensities. Using the SPV results, we show that p-type GaN exhibits n-type conductivity at low temperatures (80 K). If the sample is heated beyond a characteristic temperature, TC, the conductivity reverts to p-type. This temperature of conversion can be tuned by varying the illumination intensity. We explain this conductivity conversion using a simple, one-acceptor phenomenological model. Temperature-dependent PL measurements taken on Mg-doped p-type GaN layers show abrupt and tunable thermal quenching of the PL intensity. This effect is explained by a more complex model but with the same assertions, that the system must undergo a change in conductivity at low temperatures and under UV illumination. It is necessary to understand the observed behaviors, since the implications of such could have an effect on the performance of devices containing p-type GaN materials.

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Holthuijzen, Maike F. "A Comparison of Five Statistical Methods for Predicting Stream Temperature Across Stream Networks." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6535.

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The health of freshwater aquatic systems, particularly stream networks, is mainly influenced by water temperature, which controls biological processes and influences species distributions and aquatic biodiversity. Thermal regimes of rivers are likely to change in the future, due to climate change and other anthropogenic impacts, and our ability to predict stream temperatures will be critical in understanding distribution shifts of aquatic biota. Spatial statistical network models take into account spatial relationships but have drawbacks, including high computation times and data pre-processing requirements. Machine learning techniques and generalized additive models (GAM) are promising alternatives to the SSN model. Two machine learning methods, gradient boosting machines (GBM) and Random Forests (RF), are computationally efficient and can automatically model complex data structures. However, a study comparing the predictive accuracy among a variety of widely-used statistical modeling techniques has not yet been conducted. My objectives for this study were to 1) compare the accuracy among linear models (LM), SSN, GAM, RF, and GBM in predicting stream temperature over two stream networks and 2) provide guidelines in choosing a prediction method for practitioners and ecologists. Stream temperature prediction accuracies were compared with the test-set root mean square error (RMSE) for all methods. For the actual data, SSN had the highest predictive accuracy overall, which was followed closely by GBM and GAM. LM had the poorest performance overall. This study shows that although SSN appears to be the most accurate method for stream temperature prediction, machine learning methods and GAM may be suitable alternatives.

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Ferry, Sara Elizabeth. "Experimental simulation of crevice corrosion of a functionally graded composite system of F91 and Fe-12Cr-2Si exposed to high-temperature lead-bismuth eutectic coolant." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/76934.

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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering; and, (S.B.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2011.
"June 2011." Cataloged from PDF version of thesis.
Includes bibliographical references (p. 58-60).
In a system in which metal corrosion is of concern to its long-term structural integrity, crevice corrosion can be a significant cause of damage. Small crevices in a metal exposed to a working fluid (such as a reactor's coolant) may be prone to the development of a localized, aggressive reducing environment. If the metal relies on a passivating layer of oxides for corrosion protection, it may be vulnerable to corrosion attack within the crevice due to a drastically reduced oxygen potential and low pH. Furthermore, in a liquid metal environment, the reducing conditions combined with typically high solubilities of alloy components in the liquid metal can result in severe, localized crevice corrosion that surpasses that which might occur in the aqueous environment of a LWR. In this study, F91 and Fe-12Cr-2Si, two alloys used in previous experiments were exposed to lead-bismuth eutectic maintained at 715*C with a cover gas of pure hydrogen for thirty hours. The conditions were kept extremely reducing, via the initial removal of oxygen and the subsequent maintenance of an environment of pure hydrogen gas, in order to simulate conditions inside a crevice. Following the experiment, the materials were analyzed for corrosion damage via optical microscopy, scanning electron microscopy, and energy-dispersive x-ray spectroscopy. F91 was found to have sustained significant corrosion damage, as expected based on previous experiments, in addition to chromium depletion at the sample surface. Fe-12Cr-2Si was also found to have sustained corrosion damage as a result of lead-bismuth attack. No significant oxide formation or alloying element depletion was observed at the Fe-12Cr-2Si surface. The observed damage in Fe-12Cr-2Si was not entirely expected due to its excellent corrosion resistance in less reducing environments. This raises the concern that crevice corrosion could be an important damage mechanism in applications of the Fe-12Cr-2Si/F91 composite if crevices are present, either due to design flaws or due to cracking during service.
by Sara Elizabeth Ferry.
S.B.

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Boguta, Maria. "A New Space-Time Model for Interacting Agents in the Financial Market." Thesis, Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-3180.

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In this thesis we present a new space-time model of interacting agents in the financial market. It is a combination of the Curie-Weiss model and a model introduced by Järpe. We investigate properties such as the critical temperature and magnetization of the system. The distribution of the Hamiltonian function is obtained and a hypothesis test of independence is derived. The results are illustrated in an example based on real data.

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Turkmen, Muserref. "Digital Image Processing Of Remotely Sensed Oceanographic Data." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609948/index.pdf.

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Developing remote sensing instrumentation allows obtaining information about an area rapidly and with low costs. This fact offers a challenge to remote sensing algorithms aimed at extracting information about an area from the available re¬
mote sensing data. A very typical and important problem being interpretation of satellite images. A very efficient approach to remote sensing is employing discrim¬
inant functions to distinguish different landscape classes from satellite images. Various methods on this direction are already studied. However, the efficiency of the studied methods are still not very high. In this thesis, we will improve efficiency of remote sensing algorithms. Besides we will investigate improving boundary detection methods on satellite images.

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Musser, Daniel L. "On Propagation of Heat in Atomistic Simulations." University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1280258705.

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Jankowski, £ukasz. "Modelling and simulation of light propagation in non-aged and aged step-index polymer optical fibres." Phd thesis, Universität Potsdam, 2004. http://opus.kobv.de/ubp/volltexte/2005/173/.

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Kunststofflichtwellenleiter (POFs) stellen ein verhältnismäßig neues Medium zur optische Datenkommunikation über kurzen Strecken dar. Während ihrer Einsatzdauer unterliegen POFs unterschiedlichen Arten von Umweltbeanspruchungen, hauptsächlich durch hohe Temperatur, hohe Feuchtigkeit und mechanischen Belastungen. Zahlreiche experimentelle Forschungen beschäftigten sich mit der standardisierten Prüfung der Zuverlässigkeit von im Handel erhältlichen Fasern. Jedoch gab es bisher wenig Erfolg bei der Bemühung, zwei grundlegende optische Erscheinungen, Absorption und Streuung, die die Lichtausbreitung in Fasern stark beeinflussen, zu verstehen und praktisch zu modellieren: Diese beiden Effekte beschreiben nicht nur die Qualität neuer Fasern, sondern sie werden auch stark durch die Alterungsprozess beeinflusst.

Der Hauptzweck dieser Doktorarbeit war es, ein praktisch verwendbares und theoretisch gut fundiertes Modell der Lichtausbreitung in nicht gealterten und gealterten POFs zu entwickeln und es durch optische Experimente zu verifizieren. Dabei wurden anwendungsorientierte Aspekte mit theoretischer POF-Modellierung kombiniert. Die Arbeit enthält die erste bekannte Anwendung der Wellenanalyse zur Untersuchung der winkelabhängigen Eigenschaften der Streuung in Lichtwellenleitern.

Für die praktischen Experimente wurden mehrere POF-Proben unterschiedlicher Hersteller künstlich gealtert, indem sie bis 4500 Stunden bei 100 °C gelagert wurden (ohne Feuchtekontrolle). Die Parameter der jeweiligen Simulationen wurden mittels einer systematischen Optimierung an die gemessen optischen Eigenschaften der gealterten Proben angeglichen. Die Resultate deuten an, dass der Übertragungsverlust der gealterten Fasern in den ersten Tagen und Wochen der Alterung am stärksten durch eine wesentliche physikalische Verschlechterung der Kern-Mantel-Grenzfläche verursacht wird. Chemische Effekte des Alterungsprozesses scheinen im Faserkernmaterial zuerst nach einigen Monaten aufzutreten.
This thesis discusses theoretical and practical aspects of modelling of light propagation in non-aged and aged step-index polymer optical fibres (POFs). Special attention has been paid in describing optical characteristics of non-ideal fibres, scattering and attenuation, and in combining application-oriented and theoretical approaches. The precedence has been given to practical issues, but much effort has been also spent on the theoretical analysis of basic mechanisms governing light propagation in cylindrical waveguides.

As a result a practically usable general POF model based on the raytracing approach has been developed and implemented. A systematic numerical optimisation of its parameters has been performed to obtain the best fit between simulated and measured optical characteristics of numerous non-aged and aged fibre samples. The model was verified by providing good agreement, especially for the non-aged fibres. The relations found between aging time and optimal values of model parameters contribute to a better understanding of the aging mechanisms of POFs.

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Sundin, Daniel. "Natural gas storage level forecasting using temperature data." Thesis, Linköpings universitet, Produktionsekonomi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-169856.

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Even though the theory of storage is historically a popular view to explain commodity futures prices, many authors focus on the oil price link. Past studies have shown an increased futures price volatility on Mondays and days when natural gas storage levels are released, which could both implicate that storage levels and temperature data are incorporated in the prices. In this thesis, the U.S. natural gas storage level change is studied as a function of the consumption and production. Consumption and production are furthered segmented and separately forecasted by modelling inverse problems that are solved by least squares regression using temperature data and timeseries analysis. The results indicate that each consumer consumption segment is highly dependent of the temperature with R2-values of above 90%. However, modelling each segment completely by time-series analysis proved to be more efficient due to lack of flexibility in the polynomials, lack of used weather stations and seasonal patterns in addition to the temperatures. Although the forecasting models could not beat analysts’ consensus estimates, these present natural gas storage level drivers and can thus be used to incorporate temperature forecasts when estimating futures prices.

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Almansour, Amjad Saleh Ali. "USE OF SINGLE TOW CERAMIC MATRIX MINICOMPOSITES TO DETERMINE FUNDAMENTAL ROOM AND ELEVATED TEMPERATURE PROPERTIES." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron148640184494135.

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Item, Ann Ejimole. "Determination of Selected Heavy Metals in Some Creeks in a Tennessee City." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1249.

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Concentrations of Ni, Cu, Zn, Fe, Cd, and Pb were determined in six different creeks within a city in Tennessee using Atomic Absorption Spectrophotometer. Mean concentrations of Ni, Cu, Zn, Cd, Pb, and Fe in the sites examined reveal that they exceed the USEPA recommended limits. High concentrations of Cu (0.130 mg/L), Zn (13.7 mg/L), Ni (0.267 mg/L), and Cd (0.010 mg/L) were observed in site B and Fe (3.01 mg/L) in site E relative to other sites. The concentration of Pb (0.795 mg/l) was higher in site A. Higher concentrations of Cu, Zn, and Fe were detected in samples collected in the month of January and Cd in samples collected in the month of June. Pb and Ni concentrations did not show any significant difference with respect to dates of sample collection. Their presence in the environment on a particular day depends on the type and volume of human activities.

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So, Biu 1959. "THE METHODOLOGY AND IMPLEMENTATION OF RELAXATION METHOD TO INVESTIGATE ELECTRO-THERMAL INTERACTIONS IN SOLID-STATE INTEGRATED CIRCUITS." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276384.

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George, Lyci. "Structural Characterization of Metal Hydrides for Energy Applications." FIU Digital Commons, 2010. http://digitalcommons.fiu.edu/etd/233.

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Hydrogen can be an unlimited source of clean energy for future because of its very high energy density compared to the conventional fuels like gasoline. An efficient and safer way of storing hydrogen is in metals and alloys as hydrides. Light metal hydrides, alanates and borohydrides have very good hydrogen storage capacity, but high operation temperatures hinder their application. Improvement of thermodynamic properties of these hydrides is important for their commercial use as a source of energy. Application of pressure on materials can have influence on their properties favoring hydrogen storage. Hydrogen desorption in many complex hydrides occurs above the transition temperature. Therefore, it is important to study the physical properties of the hydride compounds at ambient and high pressure and/or high temperature conditions, which can assist in the design of suitable storage materials with desired thermodynamic properties. The high pressure-temperature phase diagram, thermal expansion and compressibility have only been evaluated for a limited number of hydrides so far. This situation serves as a main motivation for studying such properties of a number of technologically important hydrides. Focus of this dissertation was on X-ray diffraction and Raman spectroscopy studies of Mg2FeH6, Ca(BH4)2, Mg(BH4)2, NaBH4, NaAlH4, LiAlH4, LiNH2BH3 and mixture of MgH2 with AlH3 or Si, at different conditions of pressure and temperature, to obtain their bulk modulus and thermal expansion coefficient. These data are potential source of information regarding inter-atomic forces and also serve as a basis for developing theoretical models. Some high pressure phases were identified for the complex hydrides in this study which may have better hydrogen storage properties than the ambient phase. The results showed that the highly compressible B-H or Al-H bonds and the associated bond disordering under pressure is responsible for phase transitions observed in brorohydrides or alanates. Complex hydrides exhibited very high compressibility suggesting possibility to destabilize them with pressure. With high capacity and favorable thermodynamics, complex hydrides are suitable for reversible storage. Further studies are required to overcome the kinetic barriers in complex hydrides by catalytic addition. A comparative study of the hydride properties with that of the constituting metal, and their inter relationships were carried out with many interesting features.

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Karpenko, Daria. "Active Tile Self-assembly and Simulations of Computational Systems." Scholar Commons, 2015. https://scholarcommons.usf.edu/etd/5519.

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Algorithmic self-assembly has been an active area of research at the intersection of computer science, chemistry, and mathematics for almost two decades now, motivated by the natural self-assembly mechanism found in DNA and driven by the desire for precise control of nanoscale material manufacture and for the development of nanocomputing and nanorobotics. At the theoretical core of this research is the Abstract Tile Assembly Model (aTAM), the original abstract model of DNA tile self-assembly. Recent advancements in DNA nanotechnology have been made in developing strand displacement mechanisms that could allow DNA tiles to modify themselves during the assembly process by opening or closing certain binding sites, introducing new dynamics into tile self-assembly. We focus on one way of incorporating such signaling mechanisms for binding site activation and deactivation into the theoretical model of tile self-assembly by extending the aTAM to create the Active aTAM. We give appropriate definitions first for incorporating activation signals and then for incorporating deactivation signals and tile detachment into the aTAM. We then give a comparison of Active aTAM to related models, such as the STAM, and take a look at some theoretical results. The goal of the work presented here is to define and demonstrate the power of the Active aTAM with and without deactivation. To this end, we provide four constructions of temperature 1 (also known as "non-cooperative") active tile assembly systems that can simulate other computational systems. The first construction concerns the simulation of an arbitrary temperature 2 (also known as "cooperative") standard aTAM system in the sense of producing equivalent structures with a scaling factor of 2 in each dimension; the second construction generates the time history of a given 1D cellular automaton. The third and fourth constructions make use of tile detachment in order to dynamically simulate arbitrary 1D and 2D cellular automata with assemblies that record only the current state updates and not the entire computational history of the specified automaton.

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Kolacz, Jakub. "Energy Minimization in Nematic Liquid Crystal Systems Driven by Geometric Confinement and Temperature Gradients with Applications in Colloidal Systems." Kent State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=kent1448898699.

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Vasilijevic, Branislav. "Mathematical theory of quantum tunneling at positive temperature." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ59005.pdf.

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Nikolopoulos, Christos. "Mathematical modelling of modulated-temperature differential scanning calorimetry." Thesis, Heriot-Watt University, 1997. http://hdl.handle.net/10399/659.

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Tewkesbury, Heather. "Mathematical modelling of heat transfer in chocolate moulding." Thesis, University of Birmingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340442.

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Yıldırım, Eda Didem Özerdem Barış. "A mathematical model of the human thermal system/." [s.l.]: [s.n.], 2005. http://library.iyte.edu.tr/tezler/master/makinamuh/T000421.pdf.

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Wong, Laura Elizabeth. "Effects of influenza vaccination and temperature screening of day carechildren: a mathematical model." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42997951.

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Wong, Laura Elizabeth. "Effects of influenza vaccination and temperature screening of day care children a mathematical model /." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B42997951.

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Purcell, Anne 1960. "Mathematical modelling of temperature evolution in the hot rolling of steel." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=30269.

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The CANMET-McGill Mathematical Model has been expanded and improved to provide a more comprehensive predictive tool for simulation of temperature evolution in the hot rolling of steel. The model uses a Windows(TM)-based, user-friendly, graphical interface and the explicit finite-difference method in two dimensions to simulate the rolling of flat product.
Data input options were expanded to allow an initial temperature gradient in the steel to be rolled, the inclusion of a runout table in the calculations, specific chemical compositions and a choice of emissivity values.
A novel, chemistry-dependent thermal conductivity term was developed to account for the variation in heat conduction through the thickness of the steel and to ensure that the temperature of the entire cross-section is accurately predicted. In addition, the model now calculates a heat of transformation for phase changes from austenite to ferrite, pearlite and bainite.
An automated self-calibration module was included to facilitate the calibration of the model's predictions to empirically obtained temperature setpoints.
The model's temperature predictions were validated against both industrial and laboratory data with excellent results.

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Purcell, Anne. "Mathematical modelling of temperature evolution in the hot rolling of steel." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0029/MQ64245.pdf.

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Gogonel, Adriana Geanina. "Statistical Post-Processing Methods And Their Implementation On The Ensemble Prediction Systems For Forecasting Temperature In The Use Of The French Electric Consumption." Phd thesis, Université René Descartes - Paris V, 2012. http://tel.archives-ouvertes.fr/tel-00798576.

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The thesis has for objective to study new statistical methods to correct temperature predictionsthat may be implemented on the ensemble prediction system (EPS) of Meteo France so toimprove its use for the electric system management, at EDF France. The EPS of Meteo Francewe are working on contains 51 members (forecasts by time-step) and gives the temperaturepredictions for 14 days. The thesis contains three parts: in the first one we present the EPSand we implement two statistical methods improving the accuracy or the spread of the EPS andwe introduce criteria for comparing results. In the second part we introduce the extreme valuetheory and the mixture models we use to combine the model we build in the first part withmodels for fitting the distributions tails. In the third part we introduce the quantile regressionas another way of studying the tails of the distribution.

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Hess, Victor George. "Three-dimensional mathematical model of a high temperature polymer electrolyte membrane fuel cell." Doctoral thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/24481.

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Polymer electrolyte fuel cells are regarded as one of the most promising alternatives to the depleting and high pollutant fossil fuel energy sources. High temperature Polymer electrolyte fuel cells are especially suitable for stationary power applications. However, the length scale of a PEM fuel cells main components range from the micro over the meso to the macro level, and the time scales of various transport processes range from milliseconds up to a few hours. This combination of various spatial and temporal scales makes it extremely challenging to conduct in-situ measurements or other observations through experimental means. Thus, numerical simulation becomes a very important tool to help understand the underlying electrochemical dynamics and transient transport phenomena within PEM fuel cells. In this thesis research a comprehensive, three- dimensional mathematical model is developed which accounts for the convective and diffusive gas flow in the gas channel, multi-component diffusion in the porous backing layer, electrochemical reactions in the catalyst layers, as well as flow of charge and heat through the solid media. The governing equations which mathematically describe these transport processes, are discretized and solved using the finite-volume based software, Ansys FLUENT, with its in-built CFD-solvers. To handle the significant non-linearity stemming from these transport phenomena, a set of numerical under-relaxation schemes are developed using the programming language C++. Good convergence is achieved with these schemes, though the model is based on a serpentine single-channel flow approach. The model results are validated against experimental results and good agreement is achieved. The result shows that the activation overpotential is the greatest cause of voltage loss in a high temperature PEM fuel cell. The degree of oxygen depletion in the catalyst layer, under the ribs, is identified and quantified for a given set of input parameters. This factor is followed by membrane resistance to protonic migration. The model can thus be suitable applied as a tool to predict cell performance. The results also show that performance is influenced by not just one, but a combination of inter-related factors, thus temperature increases, and flow rate changes will only be effective if simultaneously, the concentration of inlet oxygen, and the mobility of proton-ions in the membrane is increased. Not only does the model results verify these phenomena, but provide a quantitative output for any given set of input parameters. It can therefore be suitably applied as an optimisation tool in high temperature PEM fuel cell design.

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Smith, Robert William. "Mathematical modelling of photoperiodic external coincidence mechanisms in the model plant, Arabidopsis thaliana." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/11734.

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As plants are sessile organisms, processes controlling plant growth and development must react to fluctuations in the external environment to aid plant survival. However, as the climate of the Earth changes and becomes more extreme, plants become less able to develop to their optimal capacity and this can have an adverse effect on crop yield and biofuel feedstock production. Thus, it is becoming increasingly important to understand the molecular mechanisms used by plants to respond to external stimuli. One important system that plants utilise in their response to environmental fluctuations is the circadian clock. The circadian clock is a time-measuring device that buffers the timing of plant growth and development against fluctuations in the local environment, such as temperature, light quality and light intensity. Importantly, the circadian clock is also able to measure day-length (photoperiod). Thus, plant development and growth is co-ordinated with photoperiod that is closely linked to seasonal changes. A key example of this is the time taken for a plant to flower. Flowering of Arabidopsis thaliana occurs specifically in long-days (LDs) of spring/summer months. Thus, the circadian clock is a key regulator promoting flowering in LD conditions. In conjunction with experimental studies, mathematical modelling has proven to be a successful method of elucidating the mechanisms that underlie complex biological systems. One example of this 'systems biology' approach is in uncovering the components that make up the Arabidopsis circadian clock mechanism. Previous research in our group has also led to the development of a model describing photoperiodic flowering that is tentatively linked to the circadian clock mechanism. In this thesis I shall develop on these models to highlight five key results: 1. using rhythmic PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and PIF5 mRNA as an example, I shall show that multiple circadian regulators are required to describe rhythmic transcription of target genes across multiple photoperiods; 2. the stabilisation of CONSTANS (CO) protein by the blue light-signalling component FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 (FKF1) is required to for flowering in LDs and has a relatively larger impact on photoperiodic flowering than FKF1-dependent degradation of CYCLING DOF FACTOR 1 (CDF1), an inhibitor of flowering; 3. multiple components of the circadian clock play specific post-translational roles in photoperiodic flowering to promote the acceleration of flowering specifically in LDs; 4. temperature regulation of photoperiodic flowering can be explained through an interaction between CO and PIF proteins, limiting the effects of temperature to a specific time-window in a 24-hour day; 5. red light- and temperature-control of the circadian clock can be explained by altering the post-translational regulation of circadian clock components.

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Weaver, Anthony T. "On assimilating sea surface temperature data into an ocean general circulation model." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29204.

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The feasibility of sea surface temperature (SST) data improving the performance of an ocean general circulation model (OGCM) is investigated through a series of idealized numerical experiments. The GFDL Bryan-Cox-Semtner primitive equation model is set-up as an eddy resolving, unforced, flat bottomed channel of uniform depth. 'Observed' SST data taken from a reference ocean established in a control run are continuously assimilated into an 'imperfect' model using a simple 'nudging' scheme based on a surface relaxation condition of the form Q = C(SST — T₁) where Q is the heat flux and T₁ is the temperature at the top level of the model. The rate of assimilation is controlled by adjusting the constant inverse relaxation time parameter C. Numerical experiments indicate that the greatest improvement in the model fields is achieved in the extreme case of infinite assimilation (i.e., C = ᅇ) in which the 'observed' SST is directly inserted into the model. This improvement is quantified by monitoring the reduction in the root mean square (RMS) errors relative to the simulated reference ocean. Assimilation with longer relaxation time-scales (i.e., smaller C's) proves quite ineffective in reducing the RMS errors. The improvement in the direct insertion numerical experiment stems from the model's ability to transfer assimilated SST into subsurface information through strong advective processes. The assimilation of cool surface data induces convective overturning which transfers the 'cool' information downward rapidly but adversely affects the vertical thermal structure by an unrealistic deepening of the mixed layer. By contrast, warm surface data do not penetrate downward readily. Thus, the systematically biased downward flux of coolness gradually produces unrealistically cool subsurface waters.
Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate

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Al-Khateeb, Ashraf Kamal. "Modelling of low-temperature laser produced plasmas." Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322766.

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Oliveira, Luiz Carlos. "Mathematical model for control of high temperature drying of southern yellow pine dimension lumber." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/76523.

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Although High temperature drying (HTD) of southern yellow pine (SYP) is extensively used, quality problems still exist. Approximately 25 percent of all green lumber (2 x 4, 2 x 6 and 2 x 8's) are degraded during HTD. Warp degrade, specifically "crook", is the main cause for the loss of quality of SYP dried at temperatures above the boiling point of water. One of the major causes of warp degrade is excessive shrinkage that results from overdrying. In industrial practices, average final moisture contents for HTD of SYP lumber are usually well below the 15% MC maximum permitted by the grading rules. Overdrying the lumber causes not only lumber quality problems, but also constitutes a waste of energy. In order to improve the overall results of HTD of SYP, it is necessary to perform a better control of the process, so unnecessary extended drying can be prevented. In this study, a mathematical model based on the temperature drop across the load (TDAL) concept was proposed. The model relates TDAL to drying rates and according to the results, it appears to be an important alternative for controlling purposes during HTD of SYP.
Ph. D.

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Koumpouras, Georgios. "Mathematical modelling of a low-temperature hydrogen production process with in situ CO₂ capture." Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/8211.

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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.

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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.

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Donlon, C. J. "An investigation of the oceanic skin temperature deviation." Thesis, University of Southampton, 1994. https://eprints.soton.ac.uk/358402/.

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Satellite and in-situ radiometric measurements of sea surface temperature (SST) together with conventional SST and meteorological parameters are used to provide a description of the ocean surface skin temperature deviation (skin temperature - bulk temperature, AT) for a transect made across the Atlantic ocean from 50°N 00°W to 23°S 35°W during September and October 1992. Methods of in-situ SST measurement are discussed and the errors associated with each technique are given. The principles of infra red radiometry are explained. The differences between the calibration strategies used to determine SST using infra-red radiometers from both in-situ and satellite platforms are reviewed and the errors associated with each technique are given. Differences between published in-situ infra red SST data indicate that there may be a bias in these data as a consequence of the calibration strategy adopted. The need for an inter calibration of in-situ infra red radiometer systems used for the validaion of satellite SST is highlighted. Satellite SST algorithms are discussed and the principles of atmospheric correction are explained. The difference between the radiometric 'skin' temperature of the ocean and the conventional 'bulk' temperature at depth is defined. A review of current observations of AT is given. Several theoretical treatments of AT are reviewed. The definitions of the surface fluxes of heat and momentum are given. A description of the collection of data and an analysis of the calibration of the infra-red radiometer used to measure the skin temperature is presented. Data have been processed to obtain AT and the surface fluxes of heat and momentum nave been evaluated according to the bulk aerodynamic formulae. The relationships between AT and the measurements made are presented for the entire data set and for day and night time observations separately. Four time series of observed data are presented and the local conditions during the time of measurement are used to discuss AT. AT has a mean value of 0.39°C ±0.3°C and is shown to be a persistent feature of the Atlantic ocean. Correlation analyses reveal the skin and bulk temperature fields to be correlated at length scales > 155 km. Night time correlations are consistently higher than the day time at all length scales. For this reason it is recommended that satellite validation data are only collected during the night. High sea states are shown to affect both in-situ and satellite observations of SST biasing these data warm. The regional nature of AT is presented which is related to the dominant atmosphere-ocean conditions for each region. AT is shown to be greatest at the higher latitudes and weak in the tropical regions. Several parameterisations of AT are used to obtain estimates of AT using the data collected. These are found to be inadequate to predict AT at small temporal scales. A regional dependence of AT is found in these parameterisations. The coefficient A, of the Saunders (1969) parameterisation has been evaluated and is shown to have a regional dependence on the local atmosphere ocean conditions. The coefficient Ci and Ci of the Hasse (1971) parameterisation have been evaluated using the data collected. These are Ci=4.74 and C2=1.22. A comparison between the Along Track Scanning Radiometer Average SST is presented. Satellite - in-situ bulk AT has been obtained and shown to be comparable to that observed in-situ. This comparison highlights the need to make skin SST validation measurements rather than bulk SST measurements. The ATSR ASST data are shown to return a SST accurate to better than 0.3°C.

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Ma, Zhiwen. "A combined differential and integral model for high temperature fuel cells." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/15831.

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Liu, Pengyu. "Maximum likelihood estimation of an unknown change-point in the parameters of a multivariate Gaussian series with applications to environmental monitoring." Pullman, Wash. : Washington State University, 2010. http://www.dissertations.wsu.edu/Dissertations/Spring2010/p_liu_041610.pdf.

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Lima, Michele Ferreira. "Modelagem da estrutura térmica e estudo da cor de um lago raso." Universidade Federal de Juiz de Fora (UFJF), 2010. https://repositorio.ufjf.br/jspui/handle/ufjf/2727.

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A Modelagem Matemática é uma ferramenta de estudo ecológico que vêm sendo aplicada ao gerenciamento de ecossistemas aquáticos com foco nos compartimentos físico, químico e biológico. Esta dissertação tratou da aplicação de um modelo hidrodinâmico tridimensional (Elcom) no Lago dos Manacás, com o objetivo de obter uma representação realista da estrutura térmica do reservatório. Uma vez calibrado, o Elcom constitui-se em uma eficiente metodologia para análise rápida dos processos de mistura e estratificação da coluna d’ água. É sabido que a circulação da água influencia na dinâmica de nutrientes e de comunidades biológicas, assim como na ressuspensão do sedimento, que atua como uma fonte de material orgânico e inorgânico para o sistema. Dessa forma, este trabalho também objetivou versar sobre as influências físicas e climáticas na biogeoquímica e coloração do lago. Nossos dados demonstraram que o Elcom foi satisfatoriamente representado na superfície da água (epilímnio), apenas com a configuração a partir de dados climáticos locais. Porém, este resultado não foi obtido na região intermediária (metalímnio) e no fundo do lago (hipolímnio). Assim, foi relevante entender as forçantes que influenciam na circulação da água, que esteve associada com ventos predominantes (NE-E) e velocidade de 7,8 m s-1. A chuva atuou de forma indireta e significativa, aumentando a vazão de entrada e promovendo o escoamento superficial. Foi observado que durante dias chuvosos de dezembro o lago manteve-se misturado e com altos níveis de turbidez e material em suspensão, que influenciam de forma indireta na cor verdadeira da água. A nossa hipótese inicial era que o Carbono Orgânico Dissolvido (COD) influenciava na cor do lago, porém esta foi derrubada, uma vez que no período estudado este não influenciou na coloração. No geral, o Lago dos Manacás não é limitado por nitrogênio e fósforo, possui estratificação química e pH neutro; altas concentrações de Ferro Total (FT) no fundo, o qual esteve relacionado com o Fosfato (FOS), uma vez que as maiores médias de FOS foram presentes quando o FT foi menor. Esse trabalho tem como perspectiva futura a aplicação dos dados biogeoquímicos em uma modelagem Ecológica (Caedym), calibrando-a no Lago dos Manacás. Assim, a modelagem acoplada Elcom – Caedym poderá ser vislumbrada para estudos futuros.
The mathematical modeling is a tool for ecological studies that has been applied to management of aquatic ecosystems with focus on physical, chemical and biological compartments. This thesis aimed to apply a three-dimensional hydrodynamic model (Elcom) in Manacás Lake, with the purpose to obtain a realistic representation of the thermal reservoir structure. When calibrated, the Elcom is an efficient methodology that can be applied for rapid analysis of the water column mixing and stratification processes. It is known that the movement of water influences the nutrient dynamics and biological communities, as well as resuspension of sediment, which acts as a source of organic and inorganic material into the system. This study also aimed to relate the physical and climatic influences on the biogeochemistry and color of the water. Our data demonstrated that Elcom has been satisfactorily represented on the water surface (epilimnion), only with local climatic configuration. However, this result was not obtained in the intermediate region (metalimnion) and in the bottom (hypolimnion). Thus, it was important to understand the forces that influence the water movements, which was associated with predominant winds (NE-E) and velocity of 7.8 m s-1; the rain acted indirectly and significantly increasing the inflow and promoting the runoff. It was observed that during rainy days in December, the lake remained mixed, with high levels of turbidity and suspended solids, which indirectly influence the true color of water. Our initial hypothesis was overthrow failed, because the Dissolved Organic Carbon (COD) did not affect the color. Overall, Manacás Lake is not limited by nitrogen and phosphorus, it presented chemical stratification, has neutral pH and high concentrations of Total Iron (TI) on the bottom, which was related to the FOS, since higher values of phosphate ( FOS), were present when the TI was lower. This work has the prospect of future application of biogeochemical data in ecological model (Caedym) and to calibrate it in Manacás Lake. Thus, the coupled modeling Elcom - Caedym can be envisioned for future studies.

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Würth, Tim Oliver [Verfasser], Joachim [Akademischer Betreuer] Escher, and Pierre [Akademischer Betreuer] Gosselet. "Mathematical modelling and analysis of temperature effects in MEMS / Tim Oliver Würth ; Joachim Escher, Pierre Gosselet." Hannover : Gottfried Wilhelm Leibniz Universität, 2019. http://d-nb.info/1197227490/34.

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Würth, Tim [Verfasser], Joachim [Akademischer Betreuer] Escher, and Pierre [Akademischer Betreuer] Gosselet. "Mathematical modelling and analysis of temperature effects in MEMS / Tim Oliver Würth ; Joachim Escher, Pierre Gosselet." Hannover : Gottfried Wilhelm Leibniz Universität, 2019. http://d-nb.info/1197227490/34.

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Henderson, Dale L. "Heuristic and exact techniques for solving a temperature estimation model /." Find on the web, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1396%5F1%5Fm.pdf&type=application/pdf.

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Dissertations / Theses on the topic 'Temperature - Mathematics'

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