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Search Results: 1 - 10 of 2179 matches for " Modelling "
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Evaluation of Best Management Practices in Millsboro Pond Watershed Using Soil and Water Assessment Tool (SWAT) Model  [PDF]
Aditya Sood, William F. Ritter
Journal of Water Resource and Protection (JWARP) , 2010, DOI: 10.4236/jwarp.2010.25047
Abstract: The Inland Bays in southern Delaware (USA) are facing eutrophication due to the nutrient loading from its watershed. The source of nutrients in the watershed is predominantly agriculture. The Millsboro Pond, a sub-watershed within the Inland Bays basin, was modeled using the Soil and Water Assessment Tool (SWAT) model. It was found that the contribution of ground water from outside the watershed had a signifi-cant impact on the hydrology of the region. Once the model was calibrated and validated, five management scenarios were implemented, one at a time, to measure its effectiveness in reducing the nutrient loading in the watershed. Among the Best Management Practices (BMPs), planting winter cover crops on the agricul-ture land was the most effective method in reducing the nutrient loads. The second most effective method was to provide grassland riparian zones. The BMPs alone were not able to achieve the nutrient load reduc-tion as required by the Total Maximum Daily Loads (TMDLs). Two extra scenarios that involved in replac-ing agriculture land with forest, first with deciduous trees and then with high yielding trees were considered. It is suggested that to achieve the required TMDL for the watershed, some parts of the agricultural land may have to be effectively converted into the managed forest with some high yielding trees such as hybrid poplar trees providing cellulose raw material for bio fuels. The remaining agriculture land should take up the prac-tice of planting winter cover crops and better nutrient management. Riparian zones, either in form of forest or grasslands, should be the final line of defense for reducing nutrient loading in the watershed.
Modelling of Internal Stresses in Sheet Glass during the Cooling  [PDF]
Saci Benbahouche, Fouad Roumili, Jean-Christophe Sangleboeuf
World Journal of Nano Science and Engineering (WJNSE) , 2011, DOI: 10.4236/wjnse.2011.12004
Abstract: Internal stresses in glass are generated by interactions between thermal contraction, elasticity at low tem-peratures, viscoelastic flow at higher temperature, and temperature gradients caused by cooling. This work intends to work out calculation program for real temperature distribution and internals stress, and to study their behaviour during the quenching through a flat plate of soda-lime glass from different temperatures.
The Static Characteristic Loop and the External Demagnetizing Factor  [PDF]
J. Takacs, Gy. Kovacs, L. K. Varga
Materials Sciences and Applications (MSA) , 2012, DOI: 10.4236/msa.2012.310100
Abstract: In this paper we demonstrate, that shearing is changing only one parameter of the static loop. By using the shearing factor Ns, linked to the widely used, demagnetization coefficient ND, we show the one parameter link between the static unsheared and that of the sheared saturation loop, obtained by a non-toroidal, open circuit hysteresis measurement. The paper illustrates the simple relation between open circuit loop data and measured real static saturation data. The proposed theory is illustrated by using the hyperbolic model. For experimental illustration, tests results are used, which were carried out on two closed and open toroidal samples, made of NO Fe-Si electrical steel sheet, mimicking the demagnetization effect of the open circuit VSM measurement. These are both theoretical and experimental demonstrations, that shearing only changes the inclination of the static hysteresis loop. These test results, presented here, agree very well with the calculated results, based on the proposed method.
What impact would an HIV/AIDS vaccine have on the HIV/AIDS epidemic in Kenya?  [PDF]
Omu Anzala, Gaudensia Nzembi Mutua, Fredrick Jack Odia Oyugi, Bashir Farah Mohamed, Thomas Achia, John Stover
Open Journal of Immunology (OJI) , 2012, DOI: 10.4236/oji.2012.24023

Objective: To estimate the potential impact of an HIV/AIDS Vaccine in Kenya. Design: The Kenyan HIV/AIDS epidemic was modeled using the most current data from national sources including epidemiology and behavioral surveillance. The model’s baseline projection was validated against adult HIV prevalence at antenatal clinics and general population surveys. The model was used to analyze the effects of scaling up current prevention programs and adding potential HIV vaccines with varying levels of effectiveness and coverage. Results: Even with full scale-up of currently available prevention, care and treatment programs, new infections will continue to burden Kenya. The introduction of a partially effective AIDS vaccine could significantly alter the trajectory of the epidemic. Conclusion: The game changing impact that an AIDS vaccine could have on the AIDS epidemic in Kenya under-scores the importance of sustaining political support and financial investment to accelerate HIV/AIDS vaccine research and development.

Modeling and Analysis of SO2 Emissions under Fast Fluidized Bed Conditions Using One Dimensional Model  [PDF]
Khurram Shahzad, Mahmood Saleem, Moinuddin Ghauri, Waqar Ali Khan, Niaz Ahmed Akhtar
Advances in Chemical Engineering and Science (ACES) , 2014, DOI: 10.4236/aces.2014.43036

Fluidized bed combustion behavior of coal and biomass is of practical interest due to its significant involvement in heating systems and power plant operations. This combustion behavior has been studied by many experimental techniques along with different kinetic models. In this study, SO2 emissions have been studied out in a pilot scale test facility of Circulating Fluidized Bed combustor (70 KW) under fast fluidized bed conditions burning coal with Pakistani wheat straw. One dimensional Mathematical model is being developed to predict the SO2 emissions under different operating conditions like bed temperature, Ca/S molar ratio, solids circulation rate, excess air ratio and secondary to primary air ratio. These parameters are varied to validate the model and encouraging correlation is found between the experimental values and model predictions.

Mechanism of Social Reproduction of the Culture Futsal: Modelling of the Universals of Futsal and Sense of the Rules of the Game: Analysis of Shooting at the European Cup Matches  [PDF]
Nejah Kacem, Ayman Guemri, Chokri Naffeti, Ali Elloumi
Advances in Physical Education (APE) , 2016, DOI: 10.4236/ape.2016.62007
Abstract: Genre and styles of Futsal playing: a comparison between the European and 2012 World Cups. This paper is the continuation of a research project started in 2012 to identify “genre” and “styles” of playing by national Futsal teams (Manno, 2012). Using a technological approach, the research addresses clinical activity concepts from an educational viewpoint that may be useful for teachers and coaches. With the assistance of a data collection method we compare various phases of the game during the 2012 World Cup with those observed in 2012. This comparison enables us to determine a “category” for each game. Furthermore, examination of how the teams’ playing changed between CE and World Cups 2012 helps us to identify particular “styles”. We then discuss our findings with a view of both initial and continuing training courses for sports teachers and Futsal coaches.
A Strategy for Development of Realistic Mathematical Models of Whole-Body Metabolism  [PDF]
Mads F. Madsen, Sune Dano, Bjorn Quistorff
Open Journal of Applied Sciences (OJAppS) , 2012, DOI: 10.4236/ojapps.2012.21002
Abstract: When realistic mathematical models of whole body metabolism eventually become available, they are likely to add entirely new dimensions to the understanding of the integrated physiological function of the organism, in particular the mechanisms governing the regulation of transitions between different physiological states, like fed-fasted, exercise-rest and normal-diseased. So far the strategy for whole body modelling has primarily been a bottom-up approach where the central problem is an apparently insurmountable barrier of complexity involved in defining and optimising the huge number of parameters. Here we follow a top-down strategy and present a complete mathematical framework for realistic whole body model development. The approach proposed is modular and hierarchical and whole body metabolism is taken as the top level. Next are the organs, where the sum of the contributions from the individual organs must equal the top level metabolism. This hierarchy can be extended to lower levels of organisation, i.e. clusters of cells, individual cells, organelle and individual pathways. Exploiting this hierarchy, metabolism at each level forms an absolute constraint on the contributions from lower level. Importantly, these constraints can in many ways be defined experimentally through mass balance and flux data. Furthermore, the constrained approach allows the lower level models to be developed independently and subsequently adapted to the whole body model. The paper describes the process of whole body modelling in practical terms, centred on a mathematical framework, devised to allow whole-body models of any complexity to be developed. Furthermore, an example of sub-model incorporation in the whole-body framework is illustrated by adapting an existing erythrocyte model to the whole body constraints. Finally, we illustrate the operation of the system by including two sets of whole-body data from humans, reflecting two different physiological states.
Evaluating Sensitivity to Different Options and Parameterizations of a Coupled Air Quality Modelling System over Bogotá, Colombia. Part I: WRF Model Configuration  [PDF]
Beatriz Reboredo, Raúl Arasa, Bernat Codina
Open Journal of Air Pollution (OJAP) , 2015, DOI: 10.4236/ojap.2015.42006
Abstract: Meteorological inputs are of great importance when implementing an air quality prediction system. In this contribution, the Weather Research and Forecast (WRF-ARW) model was used to compare the performance of the different cumulus, microphysics and Planet Boundary Layer parameterizations over Bogotá, Colombia. Surface observations were used for comparison and the evaluated meteorological variables include temperature, wind speed and direction and relative humidity. Differences between parameterizations were observed in meteorological variables and Betts-Miller-Janjic, Morrison 2-moment and BouLac schemes proved to be the best parameterizations for cumulus, microphysics and PBL, respectively. As a complement to this study, a WRF-Large Eddy Simulation was conducted in order to evaluate model results with finer horizontal resolution for air quality purposes.
Starants: A New Model for Human Networks  [PDF]
Marcia Pinheiro
Applied Mathematics (AM) , 2016, DOI: 10.4236/am.2016.73024

In this paper, we will explain the relevance of the starant graphs, graphs created by us in the year of 2002. They were basically circulant graphs with a star graph that connects to all the vertices of the circulant graphs from inside of them, but they did not exist as a separate object of study in the year of 2002, as for all we knew. We now know that they can be used to model even social networking interactions, and they do that job better than any other graph we could be trying to use there. With the development of our mathematical tools, lots of conclusions will be made much more believable and therefore will become much more likely to get support from the relevant industries when attached to new queries.

The Problem of Time  [PDF]
Li Choy Chong, Luisella Balestra
Modern Economy (ME) , 2014, DOI: 10.4236/me.2014.53026

Time is a difficult topic for the scientist. This paper investigates how this particular subject is considered in economics today and what the implications are. We demonstrate that today orthodoxy has avoided to treat the temporal element, creating a dangerous contradiction at its inside. A reconsideration of time has to be formulated, since the reintegration of the chronological entity offers better interpretations for several phenomena such as economic crisis.

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