Дисертації з теми "Estuarine pollution Mathematical models"
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1
Jiang, Dongxiang. "The application of Kriging technique to mathematical modelling of estuarine water quality." Thesis, University of Newcastle Upon Tyne, 1989. http://hdl.handle.net/10443/530.
Повний текст джерелаАнотація:
It is essential that estuarine modelling and surveying are carried out simultaneously because not only does the latter provide data required by the former but also the former is verified with data from the latter. This study integrates both research subjects from the panoramic point of view, aiming at improving modelling accuracy and reliability and increasing survey efficiency. Partially stratified estuaries are the most difficult types of estuaries to be modelled, in particular, the velocity field in such an estuary. A review of two commonly used methods to determine the velocity field, i. e., theoretical method and empirical method, revealed their inadequacies in real applications. Thus, a new approach using Kriging technique was originated and was tested on a finite element model of water quality. The model was formulated using a Galerkinfinite element method and was programmed in Fortran. Comparison between the simulation results and the field measurements for a salinity intrusion showed a high simulation accuracy. It is believed that the model in combination with the new approach would be a useful tool for estuarine modelling. The generalized Kriging method ensured that the new approach would be appropriate in practice. It was also applied to the investigation of sampling stations in the partially mixed estuary of the River Tees. It is essential to know how many sampling stations should be used and how they should be positioned. Two procedures were designed for solving the survey problems. They were the procedure of overall variance and the procedure of re-estimation. These procedures were capable of quantifing the relative significance of each sampling station and detecting redundant sampling stations. The 1975 survey was investigated, and useful conclusions were obtained.
2
蔡景華 and King-wah Choi. "Finite difference modelling of estuarine hydrodynamics." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1985. http://hub.hku.hk/bib/B30425153.
Повний текст джерела
3
Fielden, Thomas Robert. "Modeling Market and Regulatory Mechanisms for Pollution Abatement with Sharp and Random Variables." PDXScholar, 2011. https://pdxscholar.library.pdx.edu/open_access_etds/282.
Повний текст джерелаАнотація:
This dissertation is motivated by the problem of uncertainty and sensitivity in business- class models such as the carbon emission abatement policy model featured in this work. Uncertain model inputs are represented by numerical random variables and a computational methodology is developed to numerically compute business-class models as if sharp inputs were given. A new description for correlation of random variables is presented that arises spontaneously within a numerical model. Methods of numerically computing correlated random variables are implemented in software and represented. The major contribution of this work is a methodology for the numerical computation of models under uncertainty that expresses no preference for unlikelihood of model input combinations. The methodology presented here serves a sharp contrast to traditional Monte Carlo methods that implicitly equate likelihood of model input values with importance of results. The new methodology herein shifts the computational burden from likelihood of inputs to resolution of input space.
4
Chung, Nga-hang, and 鍾雅行. "Large-eddy simulation of transport of inert and chemically reactive pollutants over 2D idealized street canyons." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47849903.
Повний текст джерелаАнотація:
In view of the worsening air quality in the world, more concerns are focused on the
environment. This thesis uses the technique of CFD and develops the computer model
to investigate the wind and pollutant transport, as well as the chemistry of reactive
pollutants in idealized two-dimensional (2D) street canyons.
Three scientific questions are raised in this thesis. The first task is to find out the po-
sition with the most favorable pollutant removal along the ground level over 2D idealized
street canyon of different building-height-to-street-width (aspect) ratios (ARs). The di-
mensionless parameter, C, represents the pollutant removal performance. In the isolated
roughness regime, the two local maximum C locate at the reattachment point and the
windward corner. In the wake interference regime, C is peaked on the windward side. The
number of vertically aligned recirculations depends on the street depth in the skimming
flow regime. The sizes of the secondary recirculation upstream and downstream deter-
mine how the maximum C shifts from the street centre. After identifying the position of
peaked pollutant removal rate at the ground level, the emission source should be placed
with the highest constant C in order to remove the pollutants upward more quickly to
safeguard the street-level air quality.
After understanding the best pollutant removal in the street canyon of different ARs,
the second task is to find out what AR is the most favorable for the ventilation and
pollutant removal across the roof level. The three parameters, namely friction factor,
air exchange rate (ACH) and pollutant exchange rate (PCH), are introduced to quantify
the pressure difference to sustain the mean flow, the ventilation and pollutant removal,
respectively. The turbulence contributes more than 70% to the total ACH and PCH in
all the three flow regimes. By increasing the atmospheric turbulence in building geometry
as well as the surface roughness, the ventilation and pollutant removal performance can
be improved. The linear relation between the friction factor and ACH demonstrates the
larger resistance that in turn promotes the air exchange over the roof level.
The physical dispersion is studied; however atmospheric pollutants are seldom in-
ert but chemically reactive instead. The last task is to include the three common air
pollutants, NO, NO2 and O3, in the simple NOx ?O3 mechanism in terms of the photo-
stationary state and reaction rates. The Damkohler numbers of NO and O3, DaNO and
DaO3, are parameterized by the concentrations of the sources NO and O3. The normalized
mean and fluctuation NO, NO2 and O3 are separately considered. The integrated pho-
tostationary state (PSS) in the first canyon increases with DaO3 under the same DaNO.
The integrated PSS of the second to the twelveth street canyons are compared with each
case, the monotonic increase in the PSS from the second to twelveth canyon is perceived
in DaNO/DaO3 1, 0.03, 0.02, 0.001 and 0.000333. Further decreases the DaNO/DaO3 to
0.000143, 0.000125, 0.000118, 0.000111 and 0.0001, the PSS is found to be non-linear and
the trough appears in the fourth and fifth canyons.published_or_final_version
Mechanical Engineering
Master
Master of Philosophy
5
夏激揚 and Jiyang Xia. "Numerical study on wind field and air pollutant dispersion in urban street canopies." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31242509.
Повний текст джерела
6
Leung, Ka-kit Pieta, and 梁家杰. "On the study of ventilation and pollutant removal over idealized two-dimensional urban street canyons." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B48521863.
Повний текст джерелаАнотація:
In the last century, there has been a rapid growth and development in economy and modern technology around the world. This phenomenon helped improving wealth and living standard but also brought pollutions to the society and the environment. Among various kinds of pollution, air pollution takes a larger proportion. Therefore, there is increasing concern about the ventilation and pollution removal behavior in the urban environment.
Among different academic studies performed, the use of computational fluid dynamics (CFD) had become more popular. Since wind tunnel experiments serve as validations for CFD results, this thesis developed the technique required for wind tunnels experiments and to investigate the pollutant removal related to urban geometry, as well as the technique for gas sampling to examine the distribution of pollutants in urban boundary layer over idealized two-dimensional (2D) street canyons.
Three specific tasks are archived to accomplish the above objectives. The first task was to extend the wind tunnel in the Department of Mechanical Engineering, the University of Hong Kong. An extension duct was designed to increase the length of the test section in which the reduced-scale model could be installed. The dimensions of the test section were specified according to the required length for fully developed flow inside the test section, the environment in the laboratory and the original wind tunnel conditions. The extension duct was then constructed and mounted, with the wind profile inside the test section obtained afterwards.
After construction of the extended test section for experimental purposes, the second task was to examine the pollutant transport behaviors from the ground level of idealized 2D urban street canyons to the urban atmospheric boundary layer (ABL) using both laboratory wind tunnel measurements and CFD. Movable rectangular aluminum blocks were placed in the wind tunnel in cross-flow to construct street canyons of different building-height-to-street-width (aspect) ratios. Wetted filter papers were applied on the surface of the blocks inside the street region, modeling the source of pollutant emission inside the street canyons. The wind tunnel and CFD results complemented each other to elucidate the pollutant removal mechanism that is in line with other results available in literature. From the experimental results obtained, scaling effect was observed in the mass transfer behaviors even the flows had fulfilled kinematic similarity. A new indicator, the scaled overall pollutant removal coefficient, was formulated for the comparison of pollutant removal performance. The improved agreement in the comparison with the CFD results showed that the scaled overall pollutant removal coefficient could be used to account for the scaling effects occurred in laboratory experiments at finite Reynolds number (〖10〗^(3 ) to 〖10〗^(5 ) in this study) for comparison of pollutant removal performance.
The behavior of pollutants inside the street canyons was studied; however, the pollutant concentration inside a street could be affected by the pollutant source in another street, even there were several streets away from it. The pollutant escaped from the source street could act as air entrainment into other streets, affecting the air quality. The concentration profile correlated to the street geometry was thus studied. The last task of this dissertation was to study the effect of urban geometry on the concentration profile of the urban ABL by means of gas dispersion experiments. Experiments were carried out in the wind tunnels of the Department of Mechanical Engineering and Department of Civil Engineering with different sets of experimental models used. A special gas emission source was constructed in order to simulate the linear source due to busy traffic in the street regions. The required gas sampling techniques were also studied throughout the measurement. Trial experiments were carried out and preliminary results had been obtained. Furthermore, the pollutant concentration profiles downstream from a linear pollutant source in an idealized 2D street canyon were also measured. Throughout the experiments, different designs of line source were tested and factors affecting the experimental results were considered. One of the line source designs was adopted and the pollutant concentrations in street canyons of different aspect ratios were observed. The concentration decreases rapidly with increasing distance from the roof but then increases to steady value. The average pollutant concentration over the concentration profile was different at different aspect ratios. It is believed that its performance depends on the pollutant removal behavior from street regions.published_or_final_version
Mechanical Engineering
Master
Master of Philosophy
7
Wong, Ching-chi, and 黃精治. "Flow and pollutant dispersion over idealized urban street canyons using large-eddy simulation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/206698.
Повний текст джерелаАнотація:
Flows and pollutant dispersion over flat rural terrain have been investigated for decades. However, our understanding of their behaviours over urban areas is rather limited. Most cases have either focused on street level or in the roughness sub-layer (RSL) of urban boundary layer (UBL). Whereas, only a handful of studies have looked into the coupling between street-level and UBL-core dynamics, and their effects on pollutant dispersion.
In this thesis, computational fluid dynamics (CFD) is employed to examine the flows and pollutant transport in and over urban roughness. Idealised two-dimensional (2D) street canyons are used as the basic units fabricating hypothetical urban surfaces. A ground-level passive and chemically inert pollutant source is applied to simulate the flows and pollutant dispersion over rough surfaces in isothermal condition. Large-eddy simulation (LES) with the one-equation subgrid-scale model is used to solve explicitly the broad range of scales in turbulent flows. Arrays of idealized street canyons of both uniform and non-uniform building height are used to formulate a unified theory for the flows and pollutant dispersion over urban areas of different morphology. The geometry of roughness elements is controlled by the building-height-to-street-width (aspect) ratio (0.083 ≤ AR ≤ 2) and/or the building height variability (BHV = 0.2, 0.4 and 0.6), in which the characteristic regimes of skimming flow, wake-interference and isolated roughness are covered.
A detailed analysis on the roof-level turbulence structure reveals parcels of low-speed air masses in the streamwise flows and narrow high-speed down-drafts in the urban canopy layer, signifying the momentum entrainment into the street canyons. The decelerating streamwise flows in turn initiate up-drafts carrying pollutants away from the street canyons, illustrating the basic pollutant removal mechanism in 2D street canyons. Turbulent transport processes, in the form of ejection and sweep, are the key events governing the exchanges of air and pollutant of street canyon. Air exchange rate (ACH) along the roof level is dominated by turbulent transport, in particular over narrow street canyons.
The LES results show that both the turbulence level and ACH increase with increasing aerodynamic resistance defined in term of the Fanning friction factor. At the same AR, BHV greatly increases the friction factor and the ACH in dense built areas (AR ≤ 0.25). The turbulence intensity is peaked on the windward side of street canyons that does not overlap with the maximum velocity gradient near the leeward building corners, suggesting the importance of background turbulence in street-level ventilation. Over the building roughness, pollutant plume dispersion after the ground-level area source in cross flows resumes the self-similar Gaussian shape in the vertical direction in which the vertical plume coverage is proportional to the square root of downwind distance in the streamwise direction. Moreover, the vertical dispersion coefficient is proportional to the one-fourth power of friction factor over idealised street canyons. Conclusively, friction factor can be used to parametrise ventilation and pollutant dispersion over urban areas.published_or_final_version
Mechanical Engineering
Doctoral
Doctor of Philosophy
8
Yang, Jing Yi. "An improved algorithm for data filtering based on variation for short term air pollution prediction in Macau." Thesis, University of Macau, 2012. http://umaclib3.umac.mo/record=b2592957.
Повний текст джерела
9
Ahmad, Faheem. "Numerical modelling of transport of pollutant through soils." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-08182009-040239/.
Повний текст джерела
10
Li, Xianxiang, and 李顯祥. "Large-eddy simulation of wind flow and air pollutant transport inside urban street canyons of different aspect ratios." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40687326.
Повний текст джерела
11
Cheng, Wai-chi, and 鄭偉智. "Wind and pollutant removal of urban street canyons under different thermal stratification by RANS and LES models." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B46289653.
Повний текст джерела
12
廖俊豪 and Chun-ho Liu. "Numerical modelling of atmospheric boundary layer with application to air pollutant dispersion." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31239018.
Повний текст джерела
13
黃潤棠 and Yun-tong Anton Wong. "Computational study of wind flow and pollution dispersion in an urban street canyon of various geometries." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31226905.
Повний текст джерела
14
Yan, Tsz-leung, and 甄子良. "Spatio-temporal modeling and forecasting of air quality data." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/197498.
Повний текст джерелаАнотація:
Respirable Suspended Particulate (RSP) time series data sampled in an air quality monitoring network are found strongly correlated and they are varying in highly similar patterns. This study provides a methodology for spatio-temporal modeling and forecasting of multiple RSP time series, in which the dynamic spatial correlations amongst the series can be effectively utilized.
The efficacy of the Spatio-Temporal Dynamic Harmonic Regression (STDHR) model is demonstrated. Based on the decomposition of the observed time series into the trend and periodic components, the model is capable of making forecast of RSP data series that exhibit variation patterns during air pollution episodes and typhoons with dynamic weather conditions. It is also capable to produce spatial predictions of RSP time series up to three unobserved sites.
The Noise-variance-ratio (NVR) form of the multivariate recursive algorithm ((M2) algorithm) that derived by the author can greatly facilitate its practical application in both multivariate and univariate time series analysis. The (M2) algorithm allows the spatial correlations to be specified at parametric levels. The state-space (SS) model formulation can flexibly accommodate the existing inter or intra (auto) correlations amongst the parameters of the data series.
Applications of the variance intervention (VI) are exploited and illustrated with a real life case study which involves forecasting of RSP data series during an air pollution episode. This illustrates that time series with abrupt changes can be predicted by automatic implementation of the VI approach.
The present study also extended the anisotropic Matern model to estimate the dynamic spatial correlation structure of the air quality data by using mean wind speed and prevailing wind direction in defining the spatial anisotropy. The Anisotropic Matern model by Mean Wind Speed and Prevailing Wind Direction (AMMP) model that devised by the author can avoid huge computational burden in estimating variogram at every variation of the underlying spatial structure.
Finally, the findings of this dissertation have laid the foundation for further research on multiple time series analysis and estimation of dynamic spatial structure.published_or_final_version
Geography
Doctoral
Doctor of Philosophy
15
So, Shuk-pan Ellen, and 蘇淑彬. "Large eddy simulations of wind flow and pollution dispersion in an urban street canyon." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B29332710.
Повний текст джерела
16
Lai, Kwong-kei Murphy, and 賴廣麒. "Two-dimensional computational study on indoor/outdoor air quality relationship in urban buildings." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B38725149.
Повний текст джерела
17
Kordova-Vyhnalikova, Jana. "Mathematical modelling of atmospheric pollution : application of some eulerian-lagrangian trajectographic models to the prediction of atmospheric pollution." Université Louis Pasteur (Strasbourg) (1971-2008), 1997. http://www.theses.fr/1997STR13207.
Повний текст джерелаАнотація:
Ce memoire concerne la dispersion turbulente de particules lourdes au sein d'une couche limite turbulente. Pour ce faire, un modele eulerien d'ecoulement porteur a ete couple a une approche lagrangienne de trajectographie. La premiere etape dans l'etude du comportement dispersif de particules est de disposer d'une description suffisamment precise de l'ecoulement porteur. Le modele eulerien piapblm est concu pour simuler les ecoulements turbulents de type couche limite atmospherique. Ce modele a ete modifie pour decrire l'ecoulement de la couche limite classique. Il a ete complete par des relations algebriques deduites d'une fermeture au second ordre pour prendre en compte l'anisotropie du fluide porteur et pour decrire l'ecoulement de la sous-couche visqueuse et de la zone de tampon. La deuxieme etape de cette etude concerne le modele de trajectographie utilisant une approche statistique pour la prediction des caracteristiques de la phase dispersee. Les modifications apportees au modele concerne la simulation de la particule fluide en resolvant l'equation de langevin, la force de portance due au cisaillement, l'influence de la proximite de la paroi et les collisions particule-paroi. Le modele eulerien-lagrangien a ete valide en comparant ses resultats a ceux d'une experience recente realisee dans une soufflerie de type eiffel. Les profils simules de la vitesse moyenne du fluide sont en accord avec les profils experimentaux. On a observe l'influence de la facon de simuler la particule fluide (liee avec le probleme de la turbulence vue par la particule lourde) sur les profils de vitesse moyenne et des ecarts-types de la vitesse fluctuantes des particules lourdes. La comparaison avec une experience realisee en soufflerie est concluante. Avant son application a l'outil meteorologique, une etude atmospherique a ete effectuee en supposant la couche limite atmospherique dans les conditions de stratification stable.
18
Bhave, Prakash Viththal Seinfeld John H. "Air pollution at the single-particle level : integrating atmospheric measurements with mathematical models /." Diss., Pasadena, Calif. : California Institute of Technology, 2003. http://resolver.caltech.edu/CaltechETD:etd-05252003-091827.
Повний текст джерела
19
Basak, Rishi. "Environmental management systems and the intra-firm risk relationship." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0034/MQ64316.pdf.
Повний текст джерела
20
Tong, Yun-on, and 唐潤安. "Statistical analysis of air pollutants and numerical modeling of reactive pollutant dispersion within street canyon." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46607031.
Повний текст джерела
21
Kaharabata, Samuel K. "Non-disturbing methods of estimating trace gas emissions from agricultural and forest sources." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=35903.
Повний текст джерелаАнотація:
Two approaches, one using an atmospheric diffusion model and the other an atmospheric tracer, were used to predict the source strength of trace gases from observations of the downwind concentration field. Both approaches do not disturb the prevailing environmental and physical conditions nor the existing biogenic processes. An analytical solution to the advection-diffusion equation was used to back-calculate the source strength from the downwind concentration measurements of (i) single and multipoint (4 and 16 points) trace gas (sulphur hexafluoride (SF6) and methane (CH4)) release experiments conducted over microplots over an open field, and (ii) single point source SF6 release experiments conducted over a forested terrain. Best predictions of the source strength (to within +/-20%) were obtained from concentration observations made along the centreline of the diffusing plumes with the predictions improving when observations at the mean plume height were used. The diffusion model was then used to compute footprint estimates for neutral and unstable conditions, for tower and aircraft based observation platforms above the forest. They showed spatially constrained footprints in the surface layer, due to effective vertical coupling, so that observations from towers and low flying aircraft must be expected to be very site specific, and scaling up to larger areas will have to be done with careful consideration of surface mosaics. Above-canopy sampling of trace gases to determine volatile organic compound emissions were then interpreted in terms of footprint considerations. This was accomplished by defining the upwind canopy areas effectively sampled under the given wind and stability conditions. The analysis demonstrated, for example, that the variability observed in measured isoprene fluxes could be accounted for by varying numbers of randomly distributed clumps of emitter species within a varying footprint. It suggested that heterogeneity of the forest canopy, in terSulphur hexafluoride was also used as an atmospheric tracer in order to estimate CH4 emissions from manure slurry and cattle housed in barns and feedlots. (Abstract shortened by UMI.)
22
Tsui, Ka-cheung, and 徐家祥. "Neighborhood ventilation of a building cluster by combined forces." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B42182128.
Повний текст джерела
23
Zhao, Chun. "Impact of convection and lightning on the tropospheric chemistry composition over North America and air quality studies over East Asia." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28114.
Повний текст джерелаАнотація:
Thesis (M. S.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2009.Committee Chair: Yuhang Wang; Committee Member: Armistead Russell; Committee Member: Athanasios Nenes; Committee Member: Greg Huey; Committee Member: Judith Curry.
24
Hudson, Austin Scott. "Applications of Remote Sensing to the Study of Estuarine Physics: Suspended Sediment Dynamics in the Columbia River Estuary." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/2093.
Повний текст джерелаАнотація:
Estuarine circulation and its associated transport processes drive the environmental integrity of many near-shore habitats (the coastal ocean, rivers, estuaries and emergent wetlands). A thorough understanding and consideration of this circulation is, therefore, vital in the proper management of these habitats. The aim of this study is to bring together theory and new satellite observations in the Columbia River Estuary to increase our understanding of estuarine circulation and transport. Surface reflectance measurements gathered by the Moderate Imaging Spectroradiometer (MODIS) are first compared to in situ observations to develop an empirical model for remotely derived surface turbidity. Results indicate that MODIS data significantly correlate with in situ measurements of turbidity throughout the CRE (R2 = 0.96). Remote estimates of turbidity are then used to explore the physical processes that drive their spatial distribution. Although the response to different hydrodynamic conditions varies throughout the system, global levels of turbidity are most sensitive to fluvial and tidal inputs and increase during spring tides and high river flow. As a result, the turbidity field has temporal cycles that are consistent with the frequency of these processes. The location of the estuarine turbidity maximum (ETM) is highly dynamic and typically migrates downstream as the tidal velocity or river flow increases. The ETM becomes trapped near the Megler Bridge (river kilometer 20), however, and the presence of strong topography in this region suggests there exists an interaction between bottom topography and sediment transport.
A 2-D semi-analytical model, developed herein from the simplified Navier-Stokes equations, confirms that topographic features exhibit substantial influence on longitudinal turbidity distributions. The model considers the coupled, tidally-averaged velocity (composed of gravitational circulation, internal tidal asymmetry, and river flow) and salinity fields and assumes a condition of morphodynamic equilibrium to estimate the distribution of sediment for arbitrary channel configurations. Model simulations demonstrate that topographic highs tend to increase local seaward sediment fluxes, and that topographic lows increase local landward sediment fluxes. Sediment flux convergence near topographic highs compresses the local turbidity distribution, whereas flux divergence near topographic lows dilates the distribution and, under appropriate conditions, produces multiple ETMs.
In summary a combination of the model and satellite data has given valuable new insights into the sediment dynamics of estuarine environments; in particular, both show that turbidity distribution and ETM location vary considerably with tidal and river flow conditions, fluctuating on a variety of timescales, and are heavily influenced by bottom topography.
25
盧慧 and Hui Loo. "Effect of surface waves on pollutant dispersion." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31224866.
Повний текст джерела
26
李永智 and Wing-chi Steven Lee. "Analytical study of wind flow and pollutant dispersion past hills." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31224672.
Повний текст джерела
27
Cuifeng, Wei. "Improved Finite Analytic Methods for Solving Advection-dominated Transport Equation in Highly Variable Velocity Field." PDXScholar, 1995. https://pdxscholar.library.pdx.edu/open_access_etds/4922.
Повний текст джерелаАнотація:
Solute transport studies frequently rely on numerical solutions of the classical advection-diffusion equation. Unfortunately, solutions obtained with traditional finite difference and finite element techniques typically exhibit excessive numerical diffusion or spurious oscillation when advection dominates, especially when velocity field is highly variable. One recently developed technique, the finite analytic method, offers an attractive alternative. Finite analytic methods utilize local analytic solutions in discrete elements to obtain the algebraic representations of the governing partial differential equations, thus eliminating the truncation error in the finite difference and the use of approximating functions in the finite element method. The finite analytic solutions have been shown to be stable and numerically robust for advection-dominated transport in heterogeneous velocity fields. However, the existing finite analytic methods for solute transport in multiple dimensions have the following disadvantages. First, the method is computationally inefficient when applied to heterogeneous media due to the complexity of the formulation. Second, the evaluation of finite analytic coefficients is when the Peclet number is large. Third, the method introduces significant numerical diffusion due to inadequate temporal approximation when applied to transient problems. This thesis develops improved finite analytic methods for two-dimensional steady as well as unsteady solute transports in steady velocity fields. For steady transport, the new method exploits the advantages of the existing finite analytic and finite difference methods. The analytically difficult diffusion terms are approximated by finite difference and numerically difficult advection and reaction terms are treated analytically in a local element in deriving the numerical schemes. The new finite analytic method is extended to unsteady transport through application of Laplace transformation. Laplace transformation converts the transient equation to a steady-state expression that can be solved with the steady version of the improved finite analytic method. Numerical inversion of the transformed variables is used to recover solute concentration in the physical space-time domain. The effectiveness and accuracy of the new finite analytic method is demonstrated through stringent test examples of two dimensional steady-state transport in highly variable velocity fields. The results clearly demonstrated that the improved finite analytic methods are efficient, robust and accurate.
28
Hang, Jian, and 杭建. "Wind conditions and urban ventilation in idealized city models." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42841471.
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29
Gokgoz, Kilic Sinem. "Dynamic fugacity modeling in environmental systems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22557.
Повний текст джерелаАнотація:
Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008.Committee Chair: Aral, Mustafa; Committee Member: Guan, Jiabao; Committee Member: Pavlostathis, Spyros; Committee Member: Uzer, Turgay; Committee Member: Yiacoumi, Sotira.
30
Yu, Peng, and 于朋. "Air pollution and respiratory disease incidence of Guangzhou: a study of spatial interpolation methodsusing GIS, 2003-2004." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41633799.
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Peter, Justin R. "Numerical investigation of aerosol dynamics : evaluation of the Hamaker constant for environmental tobacco smoke." Thesis, Queensland University of Technology, 1996. https://eprints.qut.edu.au/36917/1/36917_Peter_1996.pdf.
Повний текст джерелаАнотація:
Human exposure to atmospheric pollutants (aerosols) depends on the nature and concentration of the pollutants, and also on the size distribution of the particulate phase of the aerosol. One such commonly encountered aerosol of significant physiological importance is Environmental Tobacco Smoke (ETS). Knowledge of the time evolution of combustion aerosols is necessary to understand the interactions which shape the aerosol size distribution, and thus lead to conclusions as to the health risk associated with exposure to ETS.
A systematic numerical investigation of the dynamics of aerosol coagulation with the inclusion of van der Waal's forces has been undertaken. Numerical results are compared with those obtained experimentally for the size distribution ofETS in the particle range, 10 nm < particle diameter < 1000 nm. These particles diameters lie in the Cunningham Slip-Flow region, between the free-molecule and continuum regions. The newly developed numerical method allows direct simulation to obtain the size distributions of aging aerosols of arbitrary diameter. Considering that other processes such as condensation and wall deposition are not considered, results obtained theoretically are in excellent agreement with those obtained experimentally.
The comparison of experimental and numerical results enables conclusions to be made as the value of the Hamaker constant for ETS. Although the Hamaker constant is only defined for a pure substance, the method allows an average value over all the constituents of ETS to be evaluated. This value can then be used as input for any further modelling ofETS.
32
Linde, Tamara Causer. "Relational Database Analysis of Dated Prehistoric Shorelines to Establish Sand Partitioning in Late Holocene Barriers and Beach Plains of the Columbia River Littoral Cell, Washington and Oregon, USA." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/1696.
Повний текст джерелаАнотація:
Studies of episodic shoreline accretion of the Columbia River Littoral Cell (CRLC) have been ongoing since 1964. In this study, the sediment volumes in the late Holocene barriers and beach plains are compiled and formatted in GIS compatible databases for the four sub-cells of the CRLC.
Initial evaluation involved the creation of a geodatabase of 160 dated retreat scarp positions, that were identified on across-shore GPR and borehole profiles. Ten primary timelines were identified throughout the CRLC (0-4700 ybp) and those were used to develop polygon cells. Elevation, distance measurements, and position information were all linked to the polygon through a centroid location within the geodatabase.
Once the geodatabase was completed, data was imported into MSAccessTM to create a relational database that would allow for examination of the littoral cell in its entirety or of the individual sub-cells. Within the database, sediment volumes, ages, accretion rates, sediment thicknesses, and timeline relationships were calculated and recorded.
Using the database, the accretion history of the Columbia River Littoral Cell was evaluated and this examination illustrated the complexity of the system. Northern littoral transport was shown to be an important factor in the development of the littoral cell as a whole. Total sediment volume in the littoral cell was calculated to be 1.74 x 109 m3, with a mean accretion rate of 1.90 x 104 m3/yr, which is significantly less than some previous studies. This is due to a more detailed analysis of the beach and foredune facies themselves. This is likely the result of the higher precision of beach and foredune surface information using LiDAR.
The database shows that the developmental history of the CRLC is dependent on temporal and spatial constraints that can be coupled with reverse modeling to predict shoreline erosion trends from impounded river sediments and potential global sea level rise. The North Beaches and Grayland Plains sub-cells have the greatest potential for future erosion; followed by the Clatsop Plains sub-cell.
33
Shen, Hung-Wen. "The "small-firm" problem on standard and penalty setting with incomplete enforcement." Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/33613.
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Chapman, Peter Stuart. "The outdoor horizontal and vertical variations of respirable suspendedparticulate concentrations within a densely urban environment in HongKong: application of a box and plumedispersion model (airGIS/OSPM)." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47869847.
Повний текст джерелаАнотація:
Background
There have been many multicity studies assessing health effects of the
population’s exposure to PM10. They assume that there is homogeneous exposure to PM10
and the monitoring locations are representative of the population’s exposure. In a
densely urban environment, like Hong Kong, street canyons are common and could alter
PM10 exposure. The horizontal and vertical dispersion of PM10 in the urban environment
is complex due to the interactions of street geometric, metrological and pollution source
conditions. The airGIS/OSPM is a box and plume mathematical model which was
designed to model this complex dispersion of PM10.
Objectives
This study aims to utilize the airGIS/OSPM to assess how the health impact is
affected by the misclassifications of within city air pollution exposure. This helps
assessing the feasibility of using the airGIS/OSPM in health studies.
Methods
The airGIS/OSPM was used for an urban area of Hong Kong, in the north west of
Kowloon Peninsular for a period from 1998 to spring 2011. PM10 concentration’s were
estimated at field measurement points, an EPD roadside monitoring site, and subjects in a
subset of the elderly healthcare center cohort and for all building addresses in the
modeled area.
The airGIS/OSPM was validated by conducting a PM10 measurement campaign
over the winter of 2010 to 2011. Also validation was conducted using the measurements
of the Mong Kok EPD roadside monitoring station.
A pilot study using the time stratified case-crossover analysis was conducted to
explore the effects of using the airGIS/OSPM to express the subjects’ short-term outdoor
residential exposure to PM10 on all cause mortality.
AirGIS/OSPM PM10 estimates were compared with ambient concentrations
obtained from the EPD monitoring network. The population mean exposure was
calculated using the airGIS/OSPM estimated PM10 concentration at all building address
points from 2007 to 2009 at the ground level and at middle building height level.
The airGIS/OSPM estimate was used to identify spatial variation of PM10 within
the study area.
Results
The airGIS/OSPM estimated well the measured PM10 concentration from the field
measurement campaign and the EPD Mong Kok station.
The airGIS/OSPM estimate and the ambient measure for EHC subject exposure
both found an odds ratio for all cause mortality there was no difference from unity
between case and control times.
The airGIS/OSPM derived mean PM10 concentration at the middle height of each
building was 54.8μg/m3 while that at the all EPD was 54.4μg/m3. At ground level the
airGIS/OSPM PM10 estimate was 58.35μg/m3 while that at the EPD was 54.41μg/m3.
Conclusion
The misclassification of PM10 was negligible at the middle of buildings, but for
people regularly working in ground level microenvironments are often exposed to PM10
concentrations that are higher than those measured at EPD monitors.
It is feasible to use the airGIS/OSPM model to estimate PM10 exposure. The
small spatial variation in exposure means the airGIS/OSPM may not be appropriate in
assessing the short-term PM10 exposure, but due to the larger effect size it might be
important in long-term exposure assessment.published_or_final_version
Community Medicine
Master
Master of Philosophy
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Mousavizadeh, Mohammad Hassan. "Integration of a geographic information system and a continuous nonpoint source pollution model to evaluate the hydrologic response of an agricultural watershed." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0015/NQ44524.pdf.
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Sheng, Jopan. "Multiphase immiscible flow through porous media." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/53630.
Повний текст джерелаАнотація:
A finite element model is developed for multiphase flow through soil involving three immiscible fluids: namely air, water, and an organic fluid. A variational method is employed for the finite element formulation corresponding to the coupled differential equations governing the flow of the three fluid phase porous medium system with constant air phase pressure. Constitutive relationships for fluid conductivities and saturations as functions of fluid pressures which may be calibrated from two-phase laboratory measurements, are employed in the finite element program. The solution procedure uses iteration by a modified Picard method to handle the nonlinear properties and the backward method for a stable time integration. Laboratory experiments involving soil columns initially saturated with water and displaced by p-cymene (benzene-derivative hydrocarbon) under constant pressure were simulated by the finite element model to validate the numerical model and formulation for constitutive properties. Transient water outflow predicted using independently measured capillary head-saturation data agreed well with observed outflow data. Two-dimensional simulations are presented for eleven hypothetical field cases involving introduction of an organic fluid near the soil surface due to leakage from an underground storage tank. The subsequent transport of the organic fluid in the variably saturated vadose and ground water zones is analysed.Ph. D.
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Wang, Jinjun. "Sensitivity and uncertainty analyses of contaminant fate and transport in a field-scale subsurface system." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22562.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008.Committee Chair: Aral, Mustafa; Committee Member: Guan, Jiabao; Committee Member: Kim, Seong Hee; Committee Member: Luo, Jian; Committee Member: Uzer, Turgay.
38
Cheung, Ching, and 張靜. "Effect of heat flux on wind flow and pollutant dispersion in an urban street canyon." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B37742498.
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Blue, Julie Elena. "Predicting tracer and contaminant transport with the stratified aquifer approach." Diss., The University of Arizona, 1999. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1999_426_sip1_w.pdf&type=application/pdf.
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Smith, Edwin L. "A system dynamics computer model for long-term water quality planning." Thesis, Virginia Tech, 1985. http://hdl.handle.net/10919/41562.
Повний текст джерелаАнотація:
The objective of this study was to develop a comprehensive, basin-wide, water-quality-planning model using system dynamics methodology. Later, the model was to be interfaced with a more conventional system dynamics model: one simulating social, technological, economic, and political interactions. By doing so, it is envisioned that such management policies as zoning, abatement facilities, and best management practices may be simulated together.
Master of Science
41
Moftakhari, Rostamkhani Hamed. "A Novel Approach to Flow and Sediment Transport Estimation in Estuaries and Bays." PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2185.
Повний текст джерелаАнотація:
Reliable estimates of river discharge and sediment transport to the ocean from large tidal rivers are vital for water resources management, efficient river and harbor management, navigational purposes, and climate analyses. Due to the difficulties inherent in measuring tidal-river discharge, hydrological and sedimentological records are typically too short to adequately characterize long-term (decadal) trends. Also, uncertainties associated with observation and calibration of hydrological models suggest a need for more accurate methods based on longer records of hydrodynamic parameters (e.g. tides). Tidal theory indicates that tides and river discharge interact through quadratic bed friction, which diminishes and distorts the tidal wave as discharge increases. In this study, using tidal constituents, astronomical forcing and a model of the frictional interaction of flow and tides, I propose a novel Tidal Discharge Estimate (TDE) to predict freshwater discharge with an approximate averaging interval of 18 days for time periods with tidal data but no river flow records. Next, using continuous wavelet analysis of tidal properties, I develop a method of estimating river discharge using tides measured on multiple gages along tidal rivers to improve the time-resolution and accuracy of TDE. The applicability of the Multiple-gauge Discharge Estimate (MTDE) is first demonstrated in the two largest tidal-fluvial systems of the Pacific Northwest, the Columbia River Estuary (CRE) and Fraser River Estuary (FRE). A numerical model of an idealized estuary with similar forcing as the FRE and CRE is next run under different hydrologic and morphologic scenarios to evaluate the effect of convergence, friction, and river flow variations on the applicability of MTDE.
The TDE method was applied to the San Francisco Bay, using the continuous hourly tide record available since 1858. Results show that TDE reproduces known San Francisco (SF) Bay delta inflows from 1930-present with a Nash-Sutcliffe coefficient of 0.81 and is a useful method for hindcasting historical flows from 1858 - 1929, a period that predates direct measurement of delta discharge. I also recover and digitize ~80 years of Sacramento River daily water level data between 1849 and 1946, from which river discharge to SF Bay is estimated on a daily basis, after adjusting for changes to the river channel. This discharge combined with Net Delta Outflow Index estimates (1930 - 2011) and flow estimates from tidal data (1858 - 2011) provides a more accurate version of SF Bay historic daily inflows from 1849 - 2011.
Next, the history of sediment transport and discharge into SF Bay from 1849-present is reevaluated using the daily discharge estimates. A non-stationary rating curve between river flow and sediment transport is developed, with net sedimentation observed during five bathymetric surveys that were used to constrain the total integrated sediment discharge. Results show that ~1600±320 million-tons of sediment have been delivered to SF Bay between 1850 and 2011. There has been an approximately 25 - 30% reduction of annual flow since the 19th century, along with decreased sediment supply. This has resulted in a ~60% reduction in annual sediment delivery to SF Bay. The annual hydrograph of inflow to SF Bay and the seasonality of sediment flux have changed considerably over time, due to both human alteration and climate change. Significant historic spring-melt peak floods have disappeared in the modern system and now peak flows mostly occur in winter. My flow estimation methods also confirm that the flood of January 1862 had the largest daily sediment load and the second largest daily discharge since 1849.
42
Chin, Chi-pang Henry, and 錢志鵬. "Receptor modelling of particulates pollution in Hong Kong by chemical mass balance." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1997. http://hub.hku.hk/bib/B31253696.
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Yuen, Chi-king, and 阮志敬. "Feasibility of using neural network for air dispersion modelling." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B31253325.
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Balachandran, Sivaraman. "The development, application and evaluation of advanced source apportionment methods." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50279.
Повний текст джерелаАнотація:
Ambient and indoor air pollution is a major cause of premature mortality, and has been associated with more than three million preventative deaths per year worldwide. Most of these health impacts are from the effects from fine particulate matter. It is suspected that PM2.5 health effects vary by composition, which depends on the mixture of pollutants emitted by sources. This has led to efforts to estimate relationships between sources of PM2.5 and health effects. The health effects of PM2.5 may be preferentially dependent on specific species; however, recent work has suggested that health impacts may actually be caused by the net effect of the mixture of pollutants which make up PM2.5. Recently, there have been efforts to use source impacts from source apportionment (SA) studies as a proxy for these multipollutant effects. Source impacts can be quantified using both receptor and chemical transport models (RMs and CTMs), and have both advantages and limitations for their use in health studies.
In this work, a technique is developed that reconciles differences between source apportionment (SA) models by ensemble-averaging source impacts results from several SA models. This method uses a two-step process to calculate the ensemble average. An initial ensemble average is used calculate new estimates of uncertainties for the individual SA methods that are used in the ensemble. Next, an updated ensemble average is calculated using the SA method uncertainties as weights. Finally, uncertainties of the ensemble average are calculated using propagation of errors that includes covariance terms. The ensemble technique is extended to include a Bayesian formulation of weights used in ensemble-averaging source impacts. In a Bayesian approach, probabilistic distributions of the parameters of interest are estimated using prior distributions, along with information from observed data.
Ensemble averaging results in updated estimates of source impacts with lower uncertainties than individual SA methods. Overall uncertainties for ensemble-averaged source impacts were ~45 - 74%. The Bayesian approach also captures the expected seasonal variation of biomass burning and secondary impacts. Sensitivity analysis found that using non-informative prior weighting performed better than using weighting based on method-derived uncertainties. The Bayesian-based source impacts for biomass burning correlate better with observed levoglucosan (R2=0.66) and water soluble potassium (R2=0.63) than source impacts estimated using more traditional methods, and more closely agreed with observed total mass. Power spectra of the time series of biomass burning source impacts suggest that profiles/factors associated with this source have the greatest variability across methods and locations.
A secondary focus of this work is to examine the impacts of biomass burning. First a field campaign was undertaken to measure emissions from prescribed fires. An emissions factor of 14±17 g PM2.5/kg fuel burned was determined. Water soluble organic carbon (WSOC) was highly correlated with potassium (K) (R2=.93) and levoglucosan (R2=0.98). Results using a biomass burning source profile derived from this work further indicate that source apportionment is sensitive to levels of potassium in biomass burning source profiles, underscoring the importance of quantifying local biomass burning source profiles. Second, the sensitivity of ambient PM2.5 to various fire and meteorological parameters in was examined using the method of principle components regression (PCR) to estimate sensitivity of PM2.5 to fire data and, observed and forecast meteorological parameters. PM2.5 showed significant sensitivity to PB, with a unit-based sensitivity of 3.2±1 µg m-3 PM2.5 per 1000 acres burned. PM2.5 had a negative sensitivity to dispersive parameters such as wind speed.
45
Lindgren, Magnus. "Engine exhaust gas emissions from non-road mobile machinery : effects of transient load conditions /." Uppsala : Dept. of Biometry and Engineering, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/a481.pdf.
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Hennlock, Magnus. "On strategic incentives and the management of stochastic renewable resources /." Uppsala : Dept. of Economics, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/2005124.pdf.
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Bauer, Elizabeth Nanette. "MODIFICATION OF AN EXISTING BENTHAL MODEL FOR PAPER MILL WASTES." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275443.
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MALAGRINO, WALDIR. "Bioacumulacao e eliminacao de mercurio (sup(203)Hg) no mexilhao (Perna perna, Linne, 1758) .Modelo cinetico para avaliar o risco de ingestao no homem." reponame:Repositório Institucional do IPEN, 2003. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11095.
Повний текст джерелаАнотація:
Made available in DSpace on 2014-10-09T12:48:15Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T13:56:55Z (GMT). No. of bitstreams: 1 09455.pdf: 4871108 bytes, checksum: cdb33a154f97f7b1de400d0a95b20a24 (MD5)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
49
Siddique, Sharif Rayhan. "Development of policies to ameliorate the environmental impact of cars in Perth City, using the results of a stated preference survey and air pollution modelling." University of Western Australia. Faculty of Business, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0165.
Повний текст джерелаАнотація:
[Truncated abstract] Air pollution is increasingly perceived to be a serious intangible threat to humanity, with air quality continuing to deteriorate in most urban areas. The main sources of inner city pollution are motor vehicles, which generate emissions from the tail pipe as well as by evaporation. These contain toxic gaseous components which have adverse health effects. The major components are carbon monoxide (CO), nitrogen dioxide (NO2), nitric oxide (NO), sulphur dioxide (SO2), particulates (PM10), and volatile organic compounds (VOC). CO and oxides of nitrogen (NOx) are major emissions from cars. This study focuses on pollutant concentration in Perth city and has sought to develop measures to improve air quality. To estimate concentrations, the study develops air pollution models for CO and NOx; on the basis of the model estimates, effective policy is devised to improve the air quality by managing travel to the city. Two peaks, due to traffic, are observed in hourly CO and NOx concentrations. Unlike traffic, however, the morning peak does not reach the level of the afternoon peak. The reasons for this divergence are assessed and quantified. Separate causal models of hourly concentrations of CO and NOx explain their fluctuations accurately. They take account of the complex effects of the urban street canyon and winds in the city. The angle of incidence of the wind has significant impact on pollution level; a wind flow from the south-west increases pollution and wind from the north-east decreases it. The models have been shown to be equivalent to engineering and scientific models in estimating emission rate in the context of street canyons. However the study models are much more precise in the Perth context. ... The models are used to calculate the marginal effects for all attributes and elasticity for fuel price. In almost all attributes the non-work group is more responsive than the work group. Finally, the SP model results are integrated into an econometric model for the purpose of prediction. The travel behaviour prediction is used to estimate the policy impact on air quality. The benefit from the air quality improvement is reported in terms of life saved. The estimated relationships between probability of death and air pollution determines the number of lives that could be saved under various policy scenarios. A ratio of benefits to the financial and perceived sacrifices by drivers is calculated to compare the effectiveness of the suggested policies. A car size charge policy was found to be the most cost effective measure to ameliorate the environmental impact of cars in Perth, with a morning peak entry time charge being almost as cost effective. The study demonstrates the need for appropriate modelling of air pollution and travel behaviour. It brings together analytical methods at three levels of causality, vehicle to air pollution, charge to travel response, and air pollution to health.
50
Allen, H. Joel. "A Behavioral Model for Detection of Acute Stress in Bivalves." Thesis, University of North Texas, 1998. https://digital.library.unt.edu/ark:/67531/metadc277998/.
Повний текст джерелаАнотація:
A behavioral model for acute responses in bivalves, was developed using time series analysis for use in a real-time biomonitoring unit. Stressed bivalves closed their shell and waited for the stressful conditions to pass. Baseline data showed that group behavior of fifteen bivalves was periodic, however, individuals behaved independently. Group behavior did not change over a period of 20 minutes more than 30 percent, however, following toxic exposures the group behavior changed by more than 30 percent within 20 minutes. Behavior was mathematically modeled using autoregression to compare current and past behavior. A logical alarm applied to the behavior model determined when organisms were stressed. The ability to disseminate data collected in real time via the Internet was demonstrated.