The use of catchment areas for the study of elemental mobilities is discussed with particular reference to two catchments in north-east Scotland. Underlying geology has considerable influence on their respective stream water compositions, although total annual solute output ultimately depends on the quantity of stream runoff. Tremendous fluctuations in stream water chemistry occur during storms which, it has been suggested, are due to the pathways taken by storm water through chemically contrasting soil horizons. Field sampling of this soil throughflow storm component and laboratory studies involving the leaching of undisturbed soil cores (taken at various depths down the profile) support this conclusion. Relationships between iron, aluminium and organic matter in stream water are discussed in detail. Full use of the available analytical facilities has been made with modifications to existing methods and development of new methods undertaken where necessary.

The measurement of ambient particulate concentration (PM10 and PM2.5) using active monitors requires expensive or labour-intensive apparatus or both. Although PM is a priority pollutant, this has precluded widespread or intensive ambient particulate monitoring networks to be set up in South Africa, except in some priority areas. In this study, locally manufactured passive PM monitoring devices (samplers), based on a design initially published by researchers at the University of North Carolina (UNC), were calibrated for the measurement of PM10-2.5. Duplicate samplers of each type (local and UNC) were co-located at eight reference stations equipped with TEOM (Tapered element oscillating microbalance) or BAM (Beta radiation attenuation monitor) particulate monitors in three networks. Imaging of the substrate was carried out using an optical microscope to limit the cost of analysis. The images (10 to 49 per sample) were analysed using both proprietary (Zeiss AxioVision®) and open-source (ImageJ) software at 100X and 200X magnification. Considerable variation exists between the four co-located local and UNC samplers at all stations, although the latter show lesser discrepancies when analysed using the AxioVision software. Greater agreement of the local samplers and the continuous monitors is noted at a 200X and 100X magnification using the AxioVision software with R2 = 0.81 and R2 = 0.79 respectively. The precision of PM10-2.5 measured with the passive samplers was highly variable with calculated CVs ranging from 10.4% to 73.3%. 82% of the CVs were less than 40%. The average CV for all samplers was 34.6%. Passive samplers analysed using the AxioVision software recorded smaller average discrepancies of 45.3% at 100X and 37.3% at 200X magnification. Samplers analysed using ImageJ at 100X magnification exhibited the highest percentage difference from the reference values (81.2%). Using a two factor ANOVA we can show that (at 95% confidence) the analysis software and the imaging magnification have the most significant effect on the calculated sampler concentration results. A disadvantage of passive samplers is large number of days (2-7) required to produce statistically significant values hence disqualifying it for use as a reference method. The device is, therefore, more suitable for screening-level, high spatial density sampling, but some non-regulatory applications are pointed out. / Dissertation (MEng)--University of Pretoria, 2019. / Chemical Engineering / MEng (Environmental Engineering) / Unrestricted

Thesis (M. Sc.)--University of Hong Kong, 1993.

The geographic location of Fezile Dabi District Municipality is unique in the sense that it is one of five district municipalities in the Free State Province that borders on five district municipalities and three provincial boundaries. The Vaal River, a valuable domestic, industrial and agricultural water resource for millions of South Africans, forms one of the administrative boundaries of this district municipality and of the Free State Province. However, despite the vital role the Vaal River plays in the Fezile Dabi region, there is poor water management and assessment system in place. There is a lack of intergovernmental and trans boundary efforts to assess water quality by both district municipalities and provinces. The status of the Vaal River as a visible aquatic boundary line provides an excellent opportunity to develop a trans boundary collaborative water quality monitoring strategy between Fezile Dabi District Municipality and its neighbouring district municipalities. The only way to ensure the safety of water and a healthy environment for all is by addressing the challenges of water quality monitoring in a Trans boundary, integrated and multidisciplinary manner. This study provides a strategy for Fezile Dabi District Municipality and its neighbours by proposing an ideal structure to optimise effective water quality monitoring between them. Firstly, it gives an explanation of what is meant by water quality monitoring as a key performance area of municipal health services. Secondly, information is provided and proposals made on how to integrate water quality monitoring across municipal boundaries. Thirdly, the study suggests how trans boundary collaboration can contribute to improving water quality assessment strategies between Fezile Dabi District Municipality and its adjacent district municipalities. Lastly, an exposition of an ideal organisational structure and methods to optimise effective water quality monitoring between Fezile Dabi District and these municipalities is provided. A way forward is proposed in terms of a structure negotiated and developed at an environmental health workshop held on 28–29 March 2012 in Sasolburg. / Thesis (M. Development and Management (Water Studies))--North-West University, Vaal Triangle Campus, 2013

The geographic location of Fezile Dabi District Municipality is unique in the sense that it is one of five district municipalities in the Free State Province that borders on five district municipalities and three provincial boundaries. The Vaal River, a valuable domestic, industrial and agricultural water resource for millions of South Africans, forms one of the administrative boundaries of this district municipality and of the Free State Province. However, despite the vital role the Vaal River plays in the Fezile Dabi region, there is poor water management and assessment system in place. There is a lack of intergovernmental and trans boundary efforts to assess water quality by both district municipalities and provinces. The status of the Vaal River as a visible aquatic boundary line provides an excellent opportunity to develop a trans boundary collaborative water quality monitoring strategy between Fezile Dabi District Municipality and its neighbouring district municipalities. The only way to ensure the safety of water and a healthy environment for all is by addressing the challenges of water quality monitoring in a Trans boundary, integrated and multidisciplinary manner. This study provides a strategy for Fezile Dabi District Municipality and its neighbours by proposing an ideal structure to optimise effective water quality monitoring between them. Firstly, it gives an explanation of what is meant by water quality monitoring as a key performance area of municipal health services. Secondly, information is provided and proposals made on how to integrate water quality monitoring across municipal boundaries. Thirdly, the study suggests how trans boundary collaboration can contribute to improving water quality assessment strategies between Fezile Dabi District Municipality and its adjacent district municipalities. Lastly, an exposition of an ideal organisational structure and methods to optimise effective water quality monitoring between Fezile Dabi District and these municipalities is provided. A way forward is proposed in terms of a structure negotiated and developed at an environmental health workshop held on 28–29 March 2012 in Sasolburg. / Thesis (M. Development and Management (Water Studies))--North-West University, Vaal Triangle Campus, 2013

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Thesis (M.S.)--Central Connecticut State University, 1998. / Thesis advisor: Dr. Clayton Penniman. " ... in partial fulfillment of the requirements for the degree of Master of Science in Biology." Includes bibliographical references (leaves 59-63).

Water contaminations are currently threatening ecosystems and human health on a world-wide scale. Monitoring the water quality is one of the most essential steps to provide better understanding and mitigation of water contamination. Among the water quality monitoring techniques, optofluidic technologies have created a burgeoning number of novel devices designed to test water quality in an efficient and portable format. However, current optofluidic devices have yet to be successfully translated to onsite monitoring applications due to their high cost, high maintenance and dependence on delicate laboratory instruments or bulky instruments. In this work, we developed two optofluidic platforms for onsite water quality monitoring: a fluorescence-based optofluidic platform for chemical analysis and an imaging-based optofluidic platform for microbe detection. Several technologies associated to optical sensing modules were developed to overcome the above challenges, making the optofluidic platforms compatible with onsite monitoring applications. First, excitation coupling mechanism and frequency domain time-resolved fluorescence (TRF) were developed on the fluorescence-based optofluidic platform to improve sensing sensitivity and stability, while reducing dependence on costly instruments. Their effectiveness was demonstrated by dissolved oxygen (DO) measurements and ray-tracing simulation. Second, a low-cost and portable imaging system with dual modalities were developed on the imaging-based optofluidic platform. Thus, both morphological features and fluorescent features can be observed for microbe detection without using bulky microscope setups. The effectiveness of dual-modality imaging was demonstrated by experimental results of phytoplankton analysis. Third, a fluorescence lifetime imaging (FLIM) approach was developed under a low-cost (Complementary metal–oxide–semiconductor) CMOS format. This approach enables integrating FLIM module in portable optofluidic platforms for onsite monitoring. These advances bring optofluidic platforms closer to realizing the requirements of onsite water quality monitoring and provide a clear picture for future improvements and research directions. / Thesis / Doctor of Philosophy (PhD)

Ultrasonic testing is a nondestructive structural characterization technique with limited examples of application for polymeric products due to the high signal attenuation in this class of materials. Recent developments in this thesis on ultrasonics have focused on a guided waves test method and used nonlinear analysis of harmonic frequencies to characterize polyethylene, a semi-crystalline polymer. This sensor technology was demonstrated in the detection of initial plastic deformation and to monitor solvent swelling. Frequency regions of low signal attenuation and a nonlinear ultrasonic parameter using amplitude ratio of harmonic peaks were used to classify different crystalline morphologies, controlled by thermal treatment. With an established connection between the ultrasonic spectrum signal and the internal structure of polyethylene, a quality monitoring tool was developed and applied to a batch rotational molding process. Multiple traditional quality measurements were correlated with the ultrasonic signal using multivariate statistical analysis. Finally, an in-line statistical approach for quality classification and an on-line process monitoring using dynamic process modeling were validated. The results presented in this study demonstrate the relevancy of incorporation of the ultrasonic sensor technology to promote advanced manufacturing practices for the polymer manufacturing industry. / Thesis / Doctor of Philosophy (PhD) / We have been using ultrasonic devices to investigate different things from medical diagnosis of prenatal development to nondestructive exploration of small rocks brought from the Moon. This study takes the ultrasonic testing to the challenge of characterizing plastics. Using information from the propagation of these inaudible sound waves, we can explore the entire structure and observe structural changes that can lead to defects or failures. With the help of computer-based data processing, we investigate these complex signals creating tools for more efficient manufacturing and safer products like water and fuel storage tanks.

Active travel can provide short-term and long-term health benefits and has the ability to reduce the negative externalities of vehicular traffic, for example, congestion, land consumption, and air pollution. However, exposure to air pollution is higher for pedestrians and cyclists than other road users when considering inhalation rate and travel distance. Route choice for active travel is a potential strategy to reduce the adverse impact of exposure to air pollution. Multi-use trails could be an effective way to reduce health impacts as the pollutant concentration is typically lower on trails, however, proximity to nearby roadways can deteriorate the air quality in multi-use trails. The goal of this study is to investigate the air pollutant concentrations on multi-use trails adjacent to different roadway classification and identify the factors that influence air quality in multi-use trails. I collected pollutant concentrations of PM2.5, particle number, and black carbon using mobile monitoring on an e-bike. I identified five trail routes that run parallel to an interstate highway, principal arterial, and local roads for this study and collected pollutant concentrations during morning, afternoon, and weekend afternoon peak hours. The average concentration of PM2.5, particle number, and black carbon was 15.62 µg/m3, 9,857 pt/cc, and 595.36 ng/m3 respectively among all the trail routes used for this study. I observed higher pollutant concentrations during morning peak hours than afternoon peak hours. Also, concentrations were lower on weekends than weekdays. The pollutant concentrations were different among multi-use trails based on their proximity and characteristics of nearby roadways. The pollutant concentrations significantly declined when the trail segment was 50-100 meters away as compared to segments within 50 meters of nearby interstates, freeways, or collectors. Concentrations increased significantly for trail segments having a nearby road Annual Average Daily Travel (AADT) of more than 32,000. The regression models explain 65%, 59%, and 52% of variability in the PM2.5, particle number, and black carbon concentrations respectively. Nearby road AADT and road density were found to be significant for PM2.5, particle number, and black carbon concentrations. Cooking place (rest areas with barbeque grills) and construction sites were significant and positively associated with PM2.5 concentrations. Airport and construction sites near trails showed a positive relation to the particle number concentration. Parking spaces near trails increase the concentration of black carbon along trails. This study shows the impact of roadway proximity on the air quality of trails which should be considered by municipalities while planning for multi-use trail network to mitigate health risks of pedestrians and bicyclists on trails. / Master of Urban and Regional Planning / Traffic related pollutants such as PM2.5, particle number, and black carbon can cause short and long terms health impacts. Exposure to these pollutants varies by travel mode, duration, route selection, etc. People who bike or walk have higher exposure than other users when taking the inhalation rate and travel duration into account. Hence, route choice is important in active travel. Multi-use trails could be effective to reduce exposure as the pollutant concentrations are typically lower on multi-use trails. However, multi-use trails are often in close proximity to pollution sources (i.e. roadways). This study focuses on identifying the impacts of road proximity and other determinants of air quality along multi-use trails. I selected five multi-use trails based on the classification of adjacent roadway and collected air quality data. I found that air quality differs along trails based on the proximity of nearby roadway and the trail route along interstate highway had the highest concentration of pollutants. The concentrations of pollutants were higher during morning than afternoon and also, it was higher during the weekdays than weekends. Trail segments within 0-50m distance of a nearby interstate or freeway had the highest concentration which decreased as the distance from the interstate or freeway increased. Construction site, airport, and BBQ place along trails also worsened air quality on multi-use trails. This study demonstrates the importance of selecting trail locations when planning for the trail network to improve the air quality on multi-use trails that will further improve the benefits of active travel.