Dissertations / Theses on the topic 'Tracer test'

This work successfully applied the gas-phase partitioning tracer method to determine the NAPL, water and air saturations in the vadose zone at the field scale. This project was one of the first, and still one of the few, field-scale gas-phase partitioning tracer tests. This work differs from other work in that it was conducted in a high water content, fractured clay. There were three primary components of this work. First, gas-phase tracers were identified and their NAPL-air and Henry's Law constants measured. There were four types of tracers used in this study: noble gases or nonpartitioning tracers; alkanes, which were expected to be nonpartitioning tracers; perfluorides, NAPL partitioning tracers; and halons, NAPL and water partitioning tracers. A laboratory method for measuring NAPL-air partition coefficients was developed and TCE-air partition coefficients were measured for the perfluoride and halon tracers. The second component of this study involved conducting a field-scale gas-phase partitioning tracer test, the results which were used to estimate NAPL, water and air saturations. The NAPL saturation, calculated to be an extremely low value, resulted in an estimate of NAPL mass present that is similar to the amount that has subsequently been extracted from the test site via SVE remediation. The alkane tracers, which had been used previously in laboratory column studies as nonpartitioning tracers, were more retarded than the perfluoride tracers at this site. It was the alkane tracers, and not the halon tracers, that were used to determine the water content. The water content was estimated to be approximately 90%, which is unexpectedly high for a vadose zone. Additionally, the tracer response time, vacuum data, and other geological data indicated that the tracer test was performed in fractured clay. The third component of this work comprised an analysis of the tracer test data to determine transport parameters. The analysis employed matching eight simple mathematical models to the experimental data. All of the models tested: two porous, three double-porosity, and three fracture-based (single fracture, multifracture, fracture-matrix) models could reasonably match the experimental data and no one model resulted in consistently superior predictions than the others.

ABSTRACT CHARACTERIZATION OF KIZILCAHAMAM GEOTHERMAL FIELD BY TRACER TESTING Tevfik Kaya M.S, Petroleum and Natural Gas Engineering Department Supervisor : Assoc. Prof. Dr. Serhat Akin Co-Supervisor : Prof. Dr. Mahmut Parlaktuna September 2005, 107 Pages Kizilcahamam Geothermal Field which is 70 km far from Ankara, has been utilized for Geothermal District Heating System, 25 MWt, 2500 residences capacity, greenhouses heating, thermal facilities since 1994. The average production rate is 350m3/h during the heating season , 150m3/h during the summer season for hot water and yearly average reinjection rate is 114m3/h from the field. The long term projections has been studied concerning on expected pressure decline by matching 10 years field history data which contain dynamic level and temperature data. The pressure decline is 140 kPa in the field between 1999 and 2005 with the existing reinjection rate, if the existing rates do not change, the additional pressure decline which is 120 kPa will be occurred up to 2011. In order to get more information from the field, the fluorescein as tracer has been injected in to the MTA-1, and the samples were collected from the MTA-2, Fethi Bey, IHL-1 and IHL-3 for 3 months. The fluorescein concentration has been detected by using fluorimeter, and tracer concentration time plots were analyzed. The fluoreiscein was detected in short breakthrough time in MTA-2 and Fethi Bey which are close to reinjection well, breakthrough time is longer in IHL-1 and IHL-3. The interpretation of tracer test shows that there is communication between all wells. Tracer concentration time plots were compared with different mathematical models, the best match was obtained with multi-fractured model. These results show that Kizilcahamam field is not homogeneous field. It is expected that increasing the reinjection rate will decrease the pressure decline in the field.

The hydraulic conductivity distribution in a natural porous media is characterized by a great heterogeneity that makes its spatial assessment problematic and expensive. At the same time, a detailed knowledge of the hydraulic properties, as porosity, storativity, transmissivity and hydraulic conductivity K, is fundamental for the prediction of groundwater flow and solute transport in natural formations. Among the hydraulic properties, being the subsurface transport phenomena in natural formations mainly controlled by the Darcy's law, the proper definition of the K spatial distribution at different scales plays a fundamental role to evaluate the evolution of a contaminant plume, to define the well-catchment areas or to monitor a landfill site. To estimate aquifer hydraulic properties, inverse models have long been studied and, beyond the traditional hydraulic conductivity and head measurements, tracer test analyses have been widely adopted in the past and their use have increased in the recent years thanks to a great improvement of geophysical techniques. Among others, the Electrical Resistivity Tomography (ERT) allows to monitor a tracer test injection, providing time-lapse informations about the plume evolution with limited cost. Assuming that time-lapse spatially distributed data deduced from a tracer test are available, the present work investigates different approaches aimed to the estimation of the local K distribution. At this purpose, Kalman filter based data assimilation techniques are coupled with the Lagrangian transport model and applied in different synthetic contexts
La distribuzione di conducibilità idraulica in un mezzo poroso naturale è caratterizzata da grande eterogeneità, che rende la sua determinazione problematica e costosa. Allo stesso tempo, una approfondita conoscenza delle proprietà idrauliche, quali la porosità, l'immagazzinamento specifico e la conducibilità idraulica K, è di fondamentale importanza per poter predire e analizzare il flusso sotterraneo e il trasporto di soluti in formazioni naturali. Poichè i fenomeni di trasporto sotterraneo che si realizzano negli acquiferi sono principalmente controllati dalla legge di Darcy, tra le diverse proprietà idrauliche sopraccitate, un'opportuna definizione della distribuzione spaziale di K gioca un ruolo fondamentale nella predizione del plume di inquinanti, e quindi assume particolare rilevanza in molte attività di pratico interesse, quali la definizione delle aree di salvaguardia dei pozzi o il monitoraggio di discariche. Le proprietà idrauliche degli acquiferi sono di norma stimate con l'ausilio di modelli inversi utilizzando, oltre le tradizionali misure di conducibilità idraulica e piezometria, quelle derivanti da analisi di iniezioni controllate (test con traccianti o tracer test nella comune dizione anglosassone). I test con traccianti sono stati in diverse occasioni adottati nel passato ma il loro uso è aumentato negli anni recenti grazie agli sviluppi delle tecniche geofisiche che semplificano il monitoraggio delle prove in situ. Fra queste, la Tomografia Elettrica Resistiva (ERT) sembra essere la più appropriata per misurare le quantità di interesse nel caso di iniezioni di traccianti, essendo possibile acquisire un grande numero di informazioni sull'evoluzione spazio-temporale dell'evoluzione del plume, a costi relativamente limitati. Partendo dal presupposto che siano disponibili misure derivanti da una iniezione controllata in pozzo, il presente lavoro suggerisce alcuni approcci che, sulla base dei dati deducibili dalle misure ERT, permettono di stimare la distribuzione spaziale di K e verifica la loro effettiva capacità predittiva. Tali modelli risultano dall'accoppiamento di tecniche basate sul filtro di Kalman con modelli di trasporto Lagrangiano: l'applicazione ad una estesa serie di casi sintetici ha permesso inoltre di ottenere utili indicazioni in relazione a vantaggi e svantaggi di ciascuna delle metodologie proposte

Coal provides for 77% of South Africa&rsquo
s primary energy needs and is therefore a major resource that supports the socio-economic needs of South African citizens. Power stations are the major consumers of coal in South Africa and produces electricity from burned coal. The burning of coal produces a large volume of ash that is disposed in the form of ash dump systems. The ash 
dump system is treated with high salinity process water from the power station for dust suppression. The process water contains salts due to evaporation processes from the recirculation 
 
of 
water in the cooling water system. Various studies to evaluate the sustainability of the ash dump system as a sustainable salt sink were therefore conducted. This study aimed to develop a conceptual model for the ash dump system by evaluating the movement of the process water trough the ash dump and the impacts it might have on the underlying weathered dolerite aquifer. This was achieved by evaluating the hydraulic and transport properties of the ash dump system. An initial site conceptual model was first established prior to the application of the hydraulic 
and transport methods. The initial conceptual model was based on the literature, previous reports and an initial site walk over. Known and tested hydraulic and transport methods were applied 
n bo.th field and laboratory scale for the saturated part of the ash dump system. The laboratory experiments comprised of column and core experiments. These methods assisted in 
parameter estimation of hydraulic and transport properties and also assisted in the planning of the field experiments. The field experiments were conducted in the form of slug tests, tracer 
dilution and natural gradient divergent tracer test experiments. The combined laboratory and field experiments provided statistically significant values that were then used as inputs into the 
conceptual model. Field experiments were also applied to a surrogate aquifer that represented the underlying shallow weathered dolerite aquifer of the ash dump system. The components of 
the updated conceptual model identified and investigated include the physical environment, the calculated hydraulic and transport properties.The ash dump can be conceptualized as a 20 to 
 
30 meter high heap of consolidated clay size ash 
particles built on top of an underlying shallow weathered dolerite aquifer. The ash dup is directly connected to the underlying weathered 
dolerite aquifer. The saline water within the saturated zone has the ability to move through the ash dump system with hydraulic conductivities ranging between 10-1-10- 2 m/day, with flow 
velocities of 7-8m/day and effective porosities of 1%-2%. The hydraulic properties of the ash dump are, amongst others, controlled by the ash geology, contact time of the process water with the 
sh and show a significant reduction in hydraulic conductivity over time, before reaching a steady state. The transport properties are controlled by advection and spreading in available 
pathways. Results for the surrogate underlying fractured rock aquifer show flow velocities of 31m/day and an effective porosity of 1%.This suggests that the underlying weathered dolerite 
aquifer is vulnerable to process water contamination from the ash dump system. The study illustrates the importance of a site conceptual model before the application of investigative 
methods. Hence having a site conceptual model provides an excellent platform for hydraulic and transport estimation. The development of a site conceptual model enhanced the 
understanding of flow and transport movement of the processed 
water trough the ash dump, it also assisted as a beneficial tool to enhance ash dump management.

Hydraulic fracturing is a controversial practice because of concerns about environmental impacts due to its widespread use in recovering unconventional petroleum and natural gas deposits. However, water-only hydraulic fracturing has been used safely and successfully for many years to increase the permeability of aquifers used for drinking and irrigation water supply. This process extends and widens existing bedrock fractures, allowing groundwater storage to increase. Researchers have studied the behavior of fractured-rock aquifers for decades, but little has been published on the hydraulic and mechanical properties of hydraulically enhanced fractures. In this study, a multi-faceted approach consisting of aquifer and tracer testing is used to estimate the transmissivity and storage coefficient of a hydraulically induced fracture and observe its behavior as a contaminant flow pathway. The results of the aquifer tests indicated a decrease in both the transmissivity and storage coefficient of the fracture of three orders of magnitude after cessation of pumping. The aquifer temporarily experienced incomplete recovery following pumping tests, likely due to slow recharge. After complete recovery occurred, subsequent tests showed that these hydraulic properties returned to their original values, indicating elastic compression of the fracture during periods of applied stress. The results of the tracer test indicated rapid, uniform, one-dimensional flow through the fracture, with average fluid velocity approaching 1 km/day in an induced steady flow field of 6 x 10-5 m3/s (1 gal/min) and a fracture volume of 0.238 m3 (63 gal). The complex heterogeneity of fractured-rock aquifers necessitates the use of multiple lines of testing in order to arrive at a detailed description of the behavior of these systems. This study demonstrates one effective method of investigating a single fracture that can uncover information about the behavior of a hydraulically enhanced aquifer that is otherwise difficult to obtain.
Master of Science

Interfacial partitioning tracer tests (IPTT) are one method available for measuring air-water interfacial area (A(ia)).This study used the standard approach comprising tracer injection under steady unsaturated-flow conditions with a uniform water-saturation distribution within the column. Sodium dodecylbezene sulfonate (SDBS) and pentafluorobenzoic acid (PFBA) were used as the partitioning and nonreactive tracers, respectively. Three types of porous media were used for the study: a sandy soil, a well-sorted sand, and glass beads. Initial water saturations, S(w), were approximately 80%, 80%, and 26 % for the soil, sand, and glass beads, respectively. Water saturation was monitored gravimetrically during the experiments. The maximum interfacial areas (A(ia)/(1-S(w))) calculated from the results of the experiments are compared among the three porous media used in this work, and compared to previous air-water interfacial area studies.

Hydraulic behaviour in a large denitrifying activated sludge tank, located at the Rya Wastewater treatment plant (WWTP) in Göteborg Sweden, was investigated and optimized by using fullscale tracer test and hydraulic modelling. The Rya WWTP is a high loaded plant with a small footprint. Expansion of the site is limited due to several restrictions. An efficient use of already existing facilities is therefore of great importance in order to meet the demands of decreased effluent limits, set by authorities. The presence of a short circuiting stream was identified with full-scale tracer tests and the hydraulic situation was successfully quantified using the Martin model, a compartment model based on curve fitting to the residence time distribution curve (RTD-curve) from the full-scale tracer test. Computational fluid dynamics (CFD) 3D modelling was used for virtual prototyping of different corrective measures near the inlet to break the previously identified short circuiting stream. From an operational point of view, inlet baffles were chosen as the preferable alternative. After implementation, improved tank hydraulics, were verified with another full-scale tracer test. At a normal flow (3.6 m3/s), the space time in the tank was found to be 16 minutes. In the original tank 30 % of the water had a residence time of less than 8 minutes, 49 % of the water had a residence time between 8 and 24 minutes and 21 % of the water had a residence time of more than 24 minutes. After implementation of corrective measures, the tank with baffles had 6 % of the water with a residence time of less than 8 minutes. 77 % of the water had a residence time between 8 and 24 minutes and 17 % of the water had a residence time of more than 24 minutes. Also, the mixing characteristics in the tank achieved a more plug-flow like character. Full-scale tracer tests are very informative when investigating hydraulic situations in activated sludge tanks. Mathematical modelling using black box approach can help to quantifying the hydraulics in a tank. For example can use of the Martin model help to quantify short circuiting streams and dead volumes. CFD modelling is a useful and informative tool for analyzing problematic hydraulics at wastewater treatment plants and for the design of theoretical corrective measures. Being a useful tool for virtual prototyping, this type of modelling also deserves to have a more central role when designing large reactors and other hydraulic systems.

I. Short Circuiting in a Denitryfying Activated Sludge Tank.

R. Kjellstrand, A. Mattsson, C. Niklasson and M.J. Taherzadeh.

Water Science & Technology, Vol. 52, No. 10-11, pp 79-87, IWA Publishing 2005. II. Improved Hydraulic Behaviour in a Denitrifying Activated Sludge Tank.

R. Kjellstrand, A. Mattsson.

Submitted

Orientador: Angelica Zaninelli Schreiber, Maria Luiza Moretti
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
Made available in DSpace on 2018-08-06T13:48:27Z (GMT). No. of bitstreams: 1 Loyola_AnaBeatrizAlkmimTeixeira_D.pdf: 5844968 bytes, checksum: 4d27c47d59746710e359ef7d4b61f1b7 (MD5) Previous issue date: 2005
Resumo: Os fungos filamentosos do gênero Aspergillus são fungos hialinos, saprófitas, encontrados no solo e na vegetação em decomposição e têm sido, crescentemente, relatados em casos de infecções sistêmicas ou disseminadas. A patogenicidade destes fungos oportunistas está na alta concentração dos microconídios no ar, facilitando a sua inalação. Infecções por Fusarium spp são altamente resistentes à terapia disponível, com prognostico desfavorável e taxa de mortalidade em torno de 57% dos casos. Vários relatos têm descrito a tolerância in vitro, ou resistência, de espécies de Aspergillus aos agentes antifúngicos após falha terapêutica com anfotericina B. A infecção por Aspergillus sp em pacientes imunossuprimidos apresenta taxa de mortalidade em torno de 86%, independente do tratamento antifúngico. Assim, testes de suscetibilidade a antifúngicos são de estrema importância. O teste de microdiluição, utilizando suspensão de conídios, foi recentemente padronizado pelo CLSI. No entanto, em regra, as infecções causadas por fungos filamentosos são caracterizadas pela presença de hifas no tecido infectado, sendo portanto, a realização do teste de suscetibilidade com hifas, de grande interesse clinico. A concentração inibitória mínima (CIM) de vários agentes antifúngicos pode ser determinada pela observação da inibição de crescimento de um hifa isolada. Há poucos relatos na literatura sobre a medição automatizada do crescimento de hifas de Aspergillus sp. e nenhum relato para hifas de Fusarium sp. pelo sistema 'BioCell-tracer POT. MARCA REGISTRADA¿... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital
Abstract: Aspergillus and Fusarium species are hyaline moulds that are usually found in the soil and plants. These organisms have emerged as a cause of disseminated invasive disease. It has been suggested that airborne conidia might invade the respiratory tract with primary lung or sinus localisation Fusarium species are largely resistant to available chemotherapy and are correlated with poor prognosis and lethal outcome in 57% of the cases. Several reports have described in vitro tolerance or resistance of Aspergillus spp to antifungal infection in immunossupressed patients shows mortality around 86%, independente of antifungal treatment. Antifungal susceptibility testing of filamentous fungi has therefore become more importante. Since most infections caused by filamentous fungi are characterized by the presence of hyphal elements in the tissue, the monitoring of hyphal susceptibility might be of clinical interest. The MICs of several antifungal agents cam be determined based on the growth rate of a single hypha. There are only few reports for automatic growth evaluation for Aspergillus spp and no reports for Fusarium spp using the 'BioCell-tracer POT. MARCA REGISTRADA¿ system. In this work, we selected four clinical isolates of Aspergillus and four clinical isolates of Susarium. For all strains we prodeeded microdilution and hypha susceptibility antifungal evaluation with amphotericin B and itraconazole...Note: The complete abstract is available with the full electronic digital thesis or dissertations
Doutorado
Ciencias Biomedicas
Doutor em Ciências Médicas

Permanently sequestering carbon dioxide (CO2) in gas-bearing shale formations is beneficial in that it can mitigate greenhouse gas emissions as well as enhance gas recovery in production wells. This is possible due to the sorption properties of the organic material within shales and their greater affinity for CO2 over methane. The phenomenon of preferentially adsorbing CO2 while desorbing methane has been proven in coalbed reservoirs successfully, and is feasible for shale formations. The objective of this thesis is to explore the potential for enhanced gas recovery from gas-bearing shale formations by injecting CO2 into a targeted shale formation. With the advancement of technologies in horizontal drilling combined with hydraulic fracturing, shale gas has become a significant source of energy throughout the United States. With over 6,000 trillion cubic feet (Tcf) of theoretical gas-in-place, Appalachia has proven a major basin for gas production from organic shales. With its extensive shale reserves and lack of conventional reservoirs typically used for CO2 storage, Appalachia's unconventional reservoirs are favorable candidates for CO2 storage with enhanced gas recovery. Enhancing gas recovery not only increases reserves, but extends the life of mature wells and fields throughout the basin. As part of this research, 510 tons of CO2 were successfully injected into a horizontal production well completed in the Chattanooga shale formation, a late Devonian shale, in Morgan County, Tennessee. An extensive monitoring program was implemented during the pre-injection baseline, injection, soaking, and flowback phases of the test. Multiple fluorinated tracers were used to monitor for potential CO2 breakthrough at offset production wells and to help account for the CO2 once the well was flowed back. Results from this test, once the well was put back into normal production state, confirm the injectivity and storage potential of CO2 in shale formations, as well as an increase in gas production rate and quality of gas produced.
Master of Science

When establishing a groundwater protection area it is of great interest to be able to estimate the transit time of the groundwater from different places of the aquifer to the withdrawal well. These estimates can be uncertain due to heterogeneities in the aquifer. As a part of the work to develop methods for a more certain delineation of protection areas, a tracer test was performed in an esker located 25 kilometres NW of the town Uppsala.

The purpose of this master thesis was to perform, describe and evaluate the tracer test. Travel times from the tracer test should then enable comparison against stochastic simulated travel times of the groundwater in the area.

Three dyes (rhodamine WT, uranine and naphtionate) and a salt (NaBr) were used in the tracer test. The tracers were injected in four different wells located 25 meters from a pumping well. The pumping well was pumped at a rate of 1.7 L/s and water samples were collected from the pumped water. The calculated mass recovery was large for bromide (101 %) but considerably lower for the dyes rhodamine WT (70 %), uranine (61 %) and Naphthionate (19 %). The low mass recovery for the dyes is probably due to degradation and maybe also adsorption.

An analytical solution to the advection – dispersion equation in one dimension for radial converging flow was used for the interpretation of the breakthrough curves. Smallest and largest transit time that was received from the model fitting was 1,9 days and 5,1 days respectively and without exception large longitudinal dispersivities (9-35 m). Point dilution tests were performed in the injection wells in order to determine the ground water flow at these wells. The tests gave information about the magnitude of the ground water flow, differences between the wells and the flow change at pumping.

Travel times were estimated from the received breakthrough curves and the travel time distributions can be used for comparison against stochastic simulated travel times of the groundwater.

Vid utformningen av skyddsområden för grundvattentäkter är det av stor vikt att kunna uppskatta grundvattnets transporttid (uppehållstid) från olika partier av akviferen till uttagsplatsen. Dessa bedömningar har en tendens att bli osäkra på grund av heterogeniteter i akviferen. Som ett led i arbetet att utveckla metoder för en säkrare avgränsning av skyddsområden genomfördes ett spårämnesförsök i en isälvsavlagring (Järlåsaåsen) belägen cirka 2,5 mil nordväst om Uppsala.

Syftet med examensarbetet var att genomföra, beskriva och utvärdera spårämnesförsöket. Bestämda transporttider från spårämnesförsöket skulle sedan kunna användas för jämförelse med stokastiskt simulerade transporttider för grundvattnet i området.

Tre färgspårämnen (rhodamin WT, uranin och naphtionat) och ett salt (NaBr) användes vid spårämnesförsöken. Spårämnena injicerades i fyra olika grundvattenrör belägna 25 meter från en uttagsbrunn. Pumpflödet ur uttagsbrunnen var 1,7 L/s och med en automatprovtagare togs vattenprover från det uppumpade vattnet. Resultatet från massbalansberäkningarna visade på att all injicerad bromid återfanns i uttagsbrunnen, men andelen återfunnen spårämnesmassa var betydligt lägre för färgspårämnena rhodamin WT (70 %), uranin (61 %) och naphtionat (19 %). Den låga andelen återfunnen massa beror troligtvis främst på nedbrytning och kanske även på adsorption.

En analytisk lösning till advektions- dispersionsekvationen i en dimension för radiellt konvergerande strömning användes vid utvärderingen av genombrottskurvorna. En minsta och största uppehållstid på 1,9 dygn respektive 5,1 dygn och överlag oväntat stora dispersiviteter (9 – 35 m) erhölls från kurvanpassningen. Den första ankomsttiden till uttagsbrunnen hade ett minsta och största värde på 3,8 respektive 13 timmar. Utspädningsförsök genomfördes också för att bestämma storleken på flödet vid injektionsrören. Dessa försök gav en bild av flödets storlek, skillnader mellan de olika injektionsrören och flödets förändring vid pumpning.

De bestämda transporttiderna visar på relativt stora tidsskillnader och ett heterogent försöksområde. Transporttidsfördelningarna utgör också ett underlag för en jämförelse mot stokastiskt simulerade transporttider av grundvattnet.

Geology
M.S.
Dye tracer and time-lapse ground-penetrating radar (GPR) were used to image preferential flow paths in the shallow, unsaturated zone on hillslopes in two adjacent watersheds within the Susquehanna-Shale Hills Critical Zone Observatory (CZO). At each site we injected about 50 L of water mixed with brilliant blue dye (4 g/L) into a trench cut perpendicular to the slope (~1.0 m long by ~0.20 m wide by ~0.20 m deep) to create a line of infiltration. GPR (800 MHz antennae with constant offset) was used to monitor the movement of the dye tracer downslope on a 1.0 m x 2.0 m grid with a 0.05 m line spacing. The site was then excavated and the stained pathways photographed to document the dye movement. We saw a considerable difference in the pattern of shallow preferential flow between the two sites despite similar soil characteristics and slope position. Both sites showed dye penetrating down to saprolite (~0.40 m); however, lateral flow migration between the two sites was different. At the Missed Grouse field site, the lateral migration was ~0.55 m as an evenly dispersed plume, but at distance of 0.70 m a finger of dye was observed. At the Shale Hills field site, the total lateral flow was ~0.40 m, dye was barely visible until the excavation reached ~0.10 m, and there was more evidence of distinct fingering in the vertical direction. Based on laboratory and field experiments as well as processing of the radargrams, the following conclusions were drawn: 1) time-lapse GPR successfully delineated the extent of lateral flow, but the GPR resolution was insufficient to detect small fingers of dye; 2) there was not a distinct GPR reflection at the regolith-saprock boundary, but this interface could be estimated from the extent of signal attenuation; 3) the preliminary soil moisture conditions may explain differences in the extent of infiltration at the two sites; 4) rapid infiltration into the underlying saprock limited the extent of shallow lateral flow at both sites and can be seen using the mass balance calculation and the lateral extent of dye within the radargrams; and 5) variations in flow patterns were observed between sites with similar settings at Susquehanna-Shale Hills CZO.
Temple University--Theses

Anthraquinone dyes constitute the second largest class of textile dyes, and are used extensively in the textile industry. A high fraction of the initial reactive dye mass used in the dyeing process remains in the spent dyebath. Reactive dyes are not readily removed by typical wastewater treatment processes and the high salt concentration typical of reactive dyeing further complicates the management of spent reactive dyebaths. Investigation of the reductive transformation of reactive anthraquinone dyes and their decolorization products has been very limited. Additionally, very limited research has been conducted on the decolorization of spent reactive dyebaths. Research was conducted to investigate the key operational parameters of batch and continuous-flow ZVI decolorization of a reactive anthraquinone dye, Reactive Blue 4 (RB4), under anoxic conditions, as well as the potential for the biodegradation of its decolorization products in a halophilic culture under aerobic conditions. The effect of two operational parameters, such as mixing intensity and initial dye concentration, on the ZVI batch decolorization kinetics indicates that ZVI decolorization of RB4 is a surface-catalyzed, mass transfer-limited process. The high salt and base concentrations enhanced the rate of RB4 decolorization. Based on parameters such as porosity, hydraulic conductivity, pore water velocity, and dispersion coefficient, non-ideal transport characteristics were observed in a continuous-flow ZVI column. The results of a long-term continuous-flow ZVI decolorization kinetics demonstrated that continuous-flow ZVI decolorization is feasible. However, column porosity losses and a shift of reaction kinetics occur in long-term column operation. ZVI decolorization of RB4 was successfully described with a pseudo first-order or a site saturation model. Lastly, the RB4 decolorization products generated by ZVI treatment had no inhibitory effect on the halophilic culture. However, biodegradation and/or mineralization of RB4 decolorization products was not observed after a long-term incubation of the culture. This research demonstrated the feasibility of ZVI decolorization of reactive anthraquinone dyes, which will help in the development of a continuous-flow, dyebath decolorization process and the possible reuse of the renovated dyebath in the dyeing operation. Such a system could lead to substantial reduction of water usage, as well as a decrease of salt and dye discharges.

Thesis (M.S.)--University of Toledo, 2006.
"In partial fulfillment of the requirements for the degree of Master of Science in Occupational Health." Major advisor: Sheryl Milz. Includes abstract. Document formatted into pages: iv, 66 p. Title from title page of PDF document. Title at ETD Web site: Advantages of using the ANSI/ASHRAE 110-1995 tracer gas test method versus the ANSI/AIHA Z9.5-1992 face velocity test method for chemical laboratory hood certification. Bibliography: pages 58-61.

The Karoo has been receiving considerable attention since the early 1970’s when uranium mining was at its peak, with numerous research studies being instigated to look at all aspects of uranium mining. It has recently been observed that there seems to be resurgence in uranium exploration in and around the town of Beaufort West. A study on the transport mechanisms of uranium and thorium in fractured-rock aquifers, initiated in the hope of understanding the actual processes controlling radionuclide mobilisation, is reported here. Hydrochemical investigations of the various boreholes were sampled for water quality in June, 2009. The hydrochemical description is typical of shallow fresh groundwater, changing composition to a more sulphate hydrochemical facies along the flow path. While the geochemistry of groundwater in the study area seems to have minimal effects on uranium concentrations, the low levels of uranium in boreholes sampled suggest the importance of hydrological and lithological variability on the measured concentrations. Nevertheless, the uranium concentration is within the recommended levels as specified in the US-EPA, WHO and SA water quality guidelines and thus poses no immediate threat to the general public. Analysis of pumping and tracer tests, reveals that the fractured-rock aquifer can be highly transmissive and that transport can take place via multiple flow paths having different hydraulic properties. Tracer diffusing into stagnant water zones within fracture asperities and the rock matrix are seen as an important retardation mechanism, that has implications for remediation should the aquifer be contaminated by radionuclides. In terms of conceptualising flow at a local scale, aperture sizes ranging from (563-828ìm) along with high flow velocities (1.90E-03m/s), points to the importance of bedding-plane fractures as conduits of groundwater flow. The groundwater flow has been influenced by dolerite dykes creating compartments isolated from each other, suggesting a highly complex aquifer system. Based on the conceptual model, it is shown that these structures can create unique, site specific flow conditions. The integration of all available data into the conceptual model provides an effective research tool that can be built upon as a basis for further research.
Dissertation (MSc)--University of Pretoria, 2011.
Geology
unrestricted

Streams and rivers have been modified in the past centuries for agricultural purposes. The Baltic Sea suffers from problems regarding eutrophication. Regulations of point-sources have decreased nutrient levels, but for a scattered source of nutrient pollution, streams are important. One way of mitigating nitrogen is with coupled denitrification and nitrification processes when stream water is transported through flow paths in the hyporheic zone, an area in the stream sediments where groundwater and stream water mix. Tullstorps brook is an agricultural stream that flows into the Baltic Sea. It has had problems with high nutrient loads and poor water quality and has therefore been restored. The fieldwork in this project was conducted in Tullstorps brook in May 2019, where Rhodamine WT (RWT) tracer test and Hydraulic Conductivity (HC) measurements were done in 3 reaches, and compared to similar fieldwork since before restorations, during the summer of 2015. Two reaches in an agricultural setting that have been restored, Reach 4 and Reach 6, were measured, as well as a control reach, Reach 5, which is in a natural setting. The tracer tests indicated a significant decrease in the velocity in remediated reaches. The results of exchange velocity between the stream flow and the hyporheic zone suggest an increase after remediation of the reaches and the residence time seems to be decreasing simultaneously. When comparing the hydraulic characteristics, different stream flow during measurements was considered in a qualitative manner. The results of HC measurements show a decrease from 2015 to 2019 in the remediated reaches. In Reach 4 it decreased from 1.20E-03 m/s to 5.0E-4 m/s and in Reach 6, HC decreased from 7.70E-04 m/s before remediations to 5.6E-04 m/s after remediation actions. All the measurements have uncertainties, especially since homogeneity is assumed to some extent and the natural environment will always be heterogeneous.

The saturated and unsaturated zones deeper than a few meters from the surface are difficult to study using traditional hydrogeological techniques alone (conventional soil/water sampling, in-situ test, laboratory measurements): these techniques are invasive, can modify water circulation and may provide too sparse information about subsurface processes, due to the localized and limited nature of their dataset (based on few boreholes). This is the reason why non-conventional methods are gaining popularity; in particular, a key role is played by geophysical methods: they may provide 2D/3D information (both on the subsurface spatial structures - static information - and on the fluid presence and motion - dynamic information), are non-invasive (or minimally invasive), cost-effective, and faster than traditional hydrological techniques. The most commonly applied techniques are: electrical resistivity tomography (ERT), both from the surface and in boreholes and ground penetrating radar (GPR), again in surface and borehole applications. A wide range of hydrological and hydrogeological objectives may be achieved by geophysical methodologies. These objectives can be categorized into three important areas: 1) hydrogeological mapping, 2) hydrological parameter estimation, and 3) hydrological process monitoring. The first area (hydrogeological mapping) aims to define aquifer and aquitard geometry, water table level, fault and fracture zones, and fresh-salt water interfaces. Hydraulic conductivity K (i.e. the most important hydrological parameters) is largely controlled by the heterogeneity of the subsurface; therefore, the delineation of geological structures (paleo-channels, fractures, aquitards and aquicludes), that may constitute or not preferential flow paths becomes highly important in the characterization of the shallow subsurface. The second area (hydrological parameter estimation) concerns the quantitative approaches used to estimate water content, water quality, volumetric-effective parameters. In order to translate the geophysical data into information of hydrological use, two approaches in particular can be adopted: a. empirical relationships can be used to link measurable geophysical quantities (e.g. electrical resistivity or permittivity) directly to hydrological parameters (e.g. hydraulic conductivity); b. geophysical quantities are translated into hydrological quantities (e.g. moisture content or solute concentration) that are used in turn to calibrate hydrological models and determine hydrological parameters. The first approach is typical of early applications and is often of limited value due to inconsistent assumptions. The second approach (and the most common nowadays, also applied in this study) is conceptually more robust: it recognizes that hydrological parameters are defined by hydrological constitutive models and cannot be measured via techniques that are not based on the same physical–mathematical equations. The third area (hydrological process monitoring) consists of imaging subsurface property changes, caused by natural or forced processes. Time-lapse measurements (i.e. data re-acquired in the same place at different times) image the dynamic transformations and have therefore the possibility of investigating the flow and transport processes acting in the shallow subsurface. The data shown here concern the results obtained by this hydrogeophysic approach at three different (in terms of static and dynamic properties) experimental sites: the first two sites are both located in North-Eastern Italy (Veneto Region), in a water works well field near Valdobbiadene (Treviso) and in a natural reserve near Villaverla (Vicenza); the third pilot field is placed in a contaminated area in the northern part of the city of Trento (Trentino – Alto Adige Region), also known as “Trento-Nord” site. The three case - studies proved to be successful examples of the application of boreholes and surface geophysical techniques to support conventional hydrogeological and environmental methods, in the present case represented by saline tracer tests, in complex environments. The ERT surveys yielded important results in this sense, ERT being very sensitive to conductivity contrasts at depth and thus ranking as a powerful tool in studying subsurface dynamics; however, some difficult aspects related to data collection, inversion and interpretation have to be considered. We performed different pilot-scale tests to gain some general insight into the quality of information that can or cannot be retrieved by such an integrated application.
Come ormai noto, lo studio dei processi idrogeologici sub-superficiali risulta essere fortemente limitato qualora allo scopo si utilizzino esclusivamente tecniche idrogeologiche di tipo tradizionale (campionamento suoli/acque da foro, test in-situ, misure di laboratorio): tali tecniche hanno, infatti, sempre mostrato forti restrizioni in tale ambito, principalmente a causa della natura locale delle misure e dal disturbo indotto sui campioni, oltre che dal numero necessariamente vincolato di dati ottenibili. Queste le ragioni tali per cui metodi di tipo non convenzionale stanno acquisendo sempre più popolarità nell’ambito dello studio dei principali processi che interessano la zona satura e la zona insatura del sottosuolo; tra questi metodi, un ruolo di fondamentale importanza è in particolare giocato dalle tecniche di prospezione geofisica. I metodi geofisici si rivelano, infatti, molto utili in quanto, oltre ad avere carattere non invasivo (o minimamente invasivo) ed essere versatili e relativamente economici, hanno la capacità di descrivere due aspetti del mezzo indagato: aspetti statici, ovvero quelli che non variano nel tempo, legati principalmente alle caratteristiche geometriche e alle proprietà fisico-chimiche del mezzo; aspetti dinamici, che variano nel tempo in risposta ai cambiamenti nel grado di saturazione e nella chimica dei fluidi che attraversano il mezzo. Come testimoniato dalla recente letteratura reperibile in materia, le tecniche geofisiche più comunemente applicate ai fini di cui sopra sono: la tecnica di Tomografia di Resistività Elettrica (ERT), applicata sia da superficie sia da foro, e il metodo del Ground Penetrating Radar (GPR), anche in tal caso sia da superficie sia da foro. Gli obiettivi perseguibili nello studio delle caratteristiche geologiche e idrogeologiche dei sistemi sub-superficiali mediante l’applicazione delle tecniche di tipo geofisico sono vari, tuttavia suddivisibili in tre principali categorie: 1) mappatura dei sistemi idrogeologici, 2) stima dei parametri idrologici, 3) monitoraggio dei processi idrologici. La prima area (mappatura dei sistemi idrogeologici) persegue come scopi principali la definizione e caratterizzazione geometrica di acquiferi e acquitardi, l’individuazione ad ampia scala della profondità cui si attesta il livello freatico, la delineazione di zone di faglia e fratture, nonché la delimitazione dei limiti di interfaccia acqua dolce/acqua salata. Il parametro di conducibilità idraulica K (il quale risulta essere la variabile più importante negli studi idrogeologici) è fortemente controllato dalle eterogeneità che caratterizzano il sottosuolo; un’idonea rappresentazione delle strutture sepolte (paleo-alvei, fratture, acquitardi e acquicludi), le quali possono costituire percorsi di flusso preferenziale o ostacoli a quest’ultimo, diviene quindi essere di fondamentale importanza per la caratterizzazione del sottosuolo. La seconda area (stima dei parametri idrologici) riguarda l’approccio qualitativo e/o quantitativo utilizzato ai fini della stima dei parametri idrogeologici dei mezzi in esame. A tal fine, è possibile adottare due approcci differenti, in altre parole: a. collegare quantità geofisiche misurabili (e.g. resistività elettrica o permittività dielettrica) a parametri idrologici fondamentali (e.g. conducibilità idraulica) mediante relazioni dirette (di tipo empirico); b. tradurre quantità geofisiche misurabili (e.g. resistività elettrica, velocità sismica, permittività dielettrica) in quantità idrologiche (e.g. contenuto idrico nel non saturo, concentrazione di soluti nel saturo) utili alla calibrazione di opportuni modelli di flusso o di trasporto e, successivamente, a partire da questi procedere alla stima quantitativa dei parametri di interesse (e.g. conducibilità idraulica). Il primo approccia ritrova le prime applicazioni già a partire dagli anni ’80, mostrando tuttavia deboli risultati, soprattutto a causa del carattere limitativo di alcune assunzioni teoriche di base. Il secondo approccio (attualmente il più utilizzato) risulta essere, invece, concettualmente più robusto, in quanto riconosce il fatto che determinati parametri idrologici sono definiti unicamente sulla base di modelli costitutivi e non possono essere misurati mediante tecniche geofisiche (i.e. mediante tecniche basate su equazioni fisico-matematiche di natura diversa), neppure in maniera indiretta; dall’altro lato sottolinea che determinate altre quantità idrologiche, ovvero quelle definibili solo in termini di massa o di volume, tra le quali il contenuto idrico nel non saturo (i.e. il rapporto tra volume dell’acqua e volume totale del mezzo) e la concentrazione di soluti nel saturo, meglio si prestano ad essere determinate mediante le procedure geofisiche, in quanto direttamente correlabili alle quantità fisiche elementari da queste ultime misurate. La terza area (monitoraggio dei processi idrologici) consiste infine nella mappatura delle variazioni delle proprietà del sottosuolo nel tempo, ovvero delle variazioni causate da processi naturali o forzati. Le misure geofisiche in time-lapse (i.e. misure che prevedono l’acquisizione reiterata di dati nella stessa posizione spaziale ma ad istanti di tempo differenti) permettono lo studio delle trasformazioni dinamiche che interessano i mezzi in esame e quindi offrono la possibilità di investigare sui processi di flusso e di trasporto che agiscono nei primi metri al di sotto della superficie terrestre. I dati mostrati nel presente lavoro si riferiscono ai risultati ottenuti applicando tale approccio idrogeofisico in tre differenti siti sperimentali (in termini di proprietà statiche e dinamiche): i primi due siti sono entrambi collocati nell’Italia Nord – Orientale, all’interno della Regione Veneto, in particolare il primo all’interno del campo pozzi di Valdobbiadene (Treviso), il secondo nella riserva naturale di Villaverla (Vicenza); il terzo campo pilota è invece posto in un’area contaminata a nord della città di Trento (Regione Trentino – Alto-Adige), nota anche con il nome di “Area Trento – Nord”. I tre casi di studio di cui sopra si presentano come validi esempi di applicazione di tecniche di Tomografia di Resistività Elettrica da foro e da superficie a supporto di metodi idrogeologico/ambientali di tipo convenzionale, in questo caso rappresentati dalle prove con tracciante salino. La tecnica ERT ha mostrato, infatti, ottimi risultati in tale ambito nei vari siti sperimentali, essendo questa estremamente sensibile alle variazioni di conducibilità elettrica in profondità e quindi divenendo un importante strumento conoscitivo per le dinamiche sub superficiali; nel presente lavoro saranno tuttavia messi in luce anche aspetti negativi relativi a problematiche legate alla modalità di acquisizione, inversione e interpretazione dei dati ERT. Lo scopo principale del presente studio è di mettere in luce la qualità delle informazioni che possono o non possono essere ottenute da suddette procedure integrate.

The research subject of this PhD thesis consists in the development and application of techniques for analyzing well‐log, well‐test, and tracer data to infer the distribution of hydrologic properties in heterogeneous geologic settings, including fractured rock and complex aquifer systems. This thesis is organized in an introductory section presenting the state of the art about heterogeneous geologic media characterization and a focus on flowmeter log analysis. The second chapter regards applications of an integrated surveying approach where an hydrogeophysical characterization was used for a complex aquifer in calcareous and gypsiferous formation. The most important topic is the joint use of the Electromagnetic Borehole Flowmeter (EBF) in single hole mode and the Ground Penetrating Radar in single and cross borehole configuration. The third chapter is a completion of the studies performed and described in chapter two, with an extensive study involving a conventional hydrogeological characterization (pumping test, core analysis) with flowmeter log in cross hole mode and its application to design and interpretation two tracer tests. The aim is to provide an approach to optimize a set of hydrogeological and geophysical survey techniques. In chapter four another application of the flowmeter log is presented. This application has been designed to monitor infiltration in the vadose zone of a sandy‐gravelly soil and use results as calibration data for the geophysical investigation (ERT and Georadar Borehole survey). This thesis involved coordination of laboratory and field work; collaboration with geophysicists, geochemists and geologists in interdisciplinary studies. Main applications of this work include advanced hydrogeological characterization, groundwater and vadose‐zone contaminant remediation as well as optimal utilization of water resources.

Les milieux aquifères karstiques représentent des ressources en eau importantes, particulièrement sur le pourtour méditerranéen où ils constituent la majorité des réservoirs d'eau douce souterraine. La demande en eau ayant littéralement explosée au cours de ces dernières années, ces ressources en eau constituent un facteur limitant du développement, à l'origine de conflits d'aménagements et d'usages. Il est donc nécessaire d'avoir une meilleure connaissance de ces milieux afin de proposer une exploitation appropriée, répondant aux besoins régionaux. Toutefois, ces milieux restent encore mal connus, notamment à cause de la difficulté à caractériser leur fonctionnement inhérent à l'hétérogénéité organisée de leurs écoulements. Afin d'améliorer la connaissance de ces milieux, nous avons réalisé une étude détaillée des propriétés hydrologiques de l'aquifère karstique du Lez situé en région Nord Montpelliéraine. La source du Lez alimente en eau potable la région par des pompages dans le conduit principal du réseau de drainage. Le bassin (d'une superficie d'environ 200 km²) est équipé d'un réseau dense de piézomètres, ainsi que d'un site expérimental, situé à 4.5 km au nord de la source du Lez concentrant une vingtaine de forage sur une superficie d'environ 1500 m². Ce travail porte à la fois sur 1) une caractérisation multi-échelle de l'hétérogénéité des propriétés hydrodynamiques du système, et 2) une étude du transfert de masse au sein du réservoir via analyse de traçages artificiels réalisés à l'échelle régionale et à l'échelle du site expérimental. Dans un premier temps, les essais en puits seul ont permis caractériser les différents éléments du karst et d'identifier les structures les plus transmissives. A l'échelle du site expérimental, l'analyse de l'essai de pompage a mis en évidence une connectivité globale liée à l'interface stratigraphique et une hiérarchisation des écoulements dépendante de la fracturation verticale. Enfin, l'étude des interférences des pompages du Lez à l'échelle régionale indique une compartimentation hydraulique du système. Les propriétés hydrodynamiques estimées dépendent de l'hétérogénéité structurale et des conditions hydrologiques du bassin. Le recoupement de ces différentes analyses permet une discrétisation des paramètres hydrauliques des composantes structurant les écoulements au sein d'un massif karstique. L'étude du transfert de masse à l'échelle locale et régionale complète cette caractérisation et renseigne les propriétés de transport du réseau karstique. Les essais de traçage à l'échelle du site mettent en évidence la forte hétérogénéité du milieu avec des chemins d'écoulement multiples induisant un gradient de vitesse. Tandis qu'à l'échelle régionale une corrélation des vitesses d'écoulement est observée au sein du réseau de drainage principal.L'ensemble de ces résultats fournit une meilleure connaissance à différentes échelles des propriétés et de la vulnérabilité de ces milieux complexes, constituant une base essentielle pour une modélisation hydrodynamique multi-échelle de ce type d'aquifères
Characterizing groundwater flows in karst aquifers at different scales of space and time, is not an easy task due to the high level of heterogeneity of these aquifers. Because the limited testing radius of classical hydraulic methods (slug tests, pumping tests), the regional hydraulic parameters of karst systems are generally estimated using the flow recession analysis method. But this integrative method generally does not give a differentiation into regionally varying parameters. Also, it is generally difficult to gather enough data to characterize aquifer heterogeneities at regional scale. For this reason, most of studies about hydrodynamic characterization of karst aquifer focus on local scales, i.e experimental field site scale or borehole scale; measurements at small scale could then be upscaled to obtain hydrodynamic parameters at regional scale. Consequently, understanding scale dependence of groundwater flows organization in such a context is of prime importance for the development of regional scale model.In this study, the monitoring of groundwater flow and transport is performed at several scales of time and space, within a single Mediterranean karstic carbonate aquifer, the Lez karst aquifer, located South of France. Groundwater is intensely pumped in a karst conduit upstream of the main karst outlet (Lez spring), for regional water supply. At regional scale, the relatively dense groundwater monitoring network permits to determine the hydrodynamic properties of the aquifer inferred from the hydrodynamic response to pumping at the Lez spring. At the scale of the experimental field site (Terrieu site), that comprises 22 boreholes, several experiments (i.e. pumping tests, packer tests, slug and injection tests) were performed to determine the hydrodynamic properties at experimental field site scale and borehole scale. Tracer experiments were also performed to provide an estimation of transport properties both at the scale of the experimental field site and at regional scale.The hydrodynamic properties estimated at different scale of space and time (for different hydrological conditions) were compared with flow paths organization linked to the geological structure of the reservoir. At regional scale both the hydrological conditions (i.e. high or low water level) and geological compartmentalization that impact the hydraulic connectivity, control the hydrodynamic properties. Tracer experiments revealed short time transfer and high connectivity between injection points and the spring. At the experimental field site scale, pumping and tracer test highlighted heterogeneous flow pattern that can be linked to the position of boreholes and the main geological features. At borehole scale, hydraulic tests revealed a high range of hydrodynamic properties (transmissivity from 10-11 m²/s to 10-2 m²/s) depending on the investigated part of the aquifer (matrix, fracture or drain).Depending on the water level conditions, the aquifer presents variable organization of flows that modify the hydrodynamic parameters. As expected, variability of hydrodynamic parameters depends on the scale of investigation: a difference of 10 to 105 has been quantified for a same parameter characterized at borehole scale and at regional scale. This hydrogeological parameters quantification of karst system provides important constrain about multiscale modeling using conceptual models to represent the characteristics of the main flow paths

The intra-continental movement of waterborne contaminants is governed by the distribution of solute load in the landscape along with the characteristics and distribution of the hydrological pathways that transport the solutes. An understanding of the processes affecting the transport and fate of the contaminants is crucial for assessments of solute concentrations and their environmental effect on downstream recipients. Elevated concentration of nutrients and the presence of anthropogenic substances, such as pharmaceutical residues, are two examples of the current problems related to hydrological transport. The overall objective of this thesis is to increase the mechanistic understanding of the governing hydrological transport processes and their links to geomorphological and biogeochemical retention and attenuation processes. Specifically, this study aims to quantify the processes governing the transport and fate of waterborne contaminants on the point, stream reach, and watershed scales by evaluating time series obtained from stream tracer tests and water quality monitoring data. The process quantification was achieved by deriving formal expressions for the key transport characteristics, such as the central temporal moments of a unit solute response function and the spectral scaling function for time series of solute responses, which attributes the solute response in the Laplace and Fourier domains to the governing processes and spatial regions within the watershed. The results demonstrate that in addition to the hydrological and biogeochemical processes, the distribution of the load in the landscape and the geomorphological properties in terms of the distribution of transport pathway distances have defined effects on the solute response. Furthermore, the spatial variability between and along the transport pathways significantly affect the solute response. The results indicate that environments with high retention and attenuation intensity, such as stream-reaches with pronounced hyporheic zones, may often dominate the solute flux in the watershed effluent, especially for reactive solutes. The mechanistic-based framework along with the evaluation methodologies presented within this study describes how the results can be generalized in terms of model parameters that reflect the hydrology, geomorphology and biogeochemistry in the studied area. This procedure is demonstrated by the parameterization of a compartment-in-series model for phosphorous transport.

QC 20140826

Groundwater issues are among the most important sustainability studies related to topics considered as critical point for the future of planet Earth(Gleeson et al., 2010) in the perspective of a sustainable world. Analyses are focused on two complementary aspects: quantity and quality.Thus, once physical behaviour is analysed, it is coupled with chemical characterisation studies, in order to obtain a better view of an investigated site.The work begins with a brief overview of the literature which summarizes the challenges of teaching hydrogeology by theoretical lessons coupled with practical activities. The focus is on laboratory experiments implemented on physical models. In fact, to fully understand the process of groundwater flow and solute transport, and to demonstrate the basics fundamental concepts behind, it is important to visualize them in a lab-scale. This thesis is undertaken in the context of the installation of a 3D physical model at the University of Liège as a support to teaching and research works: dimension, set up, construction and support devices used for system optimal functioning are presented. The global aim of the work is to prepare everything needed to set up the sand tank. This is a fundamental step in order to be able to pre-dimension real experiments, to give ideas about the magnitude order of the expected results and to check the reliability of mathematical results and/or low-dimensionality models. Part of the document is centred on the characterization of porous aquifer materials to implement in the physical model, in particular through sand column one-dimensional lab experiments performed on four distinguished types of quartz sands (differentiated by the particles size) in particular a Constant Head Permeability Test and a Salt Tracer Test(KCl).A numerical model of the 3D tank is also developed by the use of GMS-MODFLOW-MT3DS and few experiments are simulated(gradient variation, pumping test at different pumping rates and tracer test).

The phenomenon of plume persistence was observed for five federal Superfund sites by analysis of historical groundwater-withdrawal and contaminant-concentration data collected from long-term pump-and-treat operations. The potential factors contributing to plume persistence are generally recognized to include incomplete isolation of the source zone, permeability heterogeneity, well-field hydraulics, and non-ideal (rate-limited, nonlinear) desorption. However, the significance of each factor, especially the site-specific contribution is undetermined, which is very important for site development and management. One objective of this study is to quantify the impacts of different factors on mass-removal efficiency. Three-dimensional (3D) numerical models were used to simulate the impact of different well-field configurations on pump-and-treat mass removal. The relationship between reduction in contaminant mass discharge (CMDR) and mass removal (MR) was used as the metric to examine remediation efficiency. Results indicate that (1) even with effort to control the source, residual impact of source can still be a factor causing plume persistence, (2) the well-field configuration has a measurable impact on mass-removal efficiency, which can be muted by the influence of permeability heterogeneity, (3) in terms of permeability heterogeneity, both variance and correlation scale influence the overall mass-removal behavior, (4) the CMDR-MR relationship can be used to quantify the impacts of different factors on mass-removal efficiency at the plume scale. It has been recognized that the use of pump and treat for groundwater remediation will require many decades to attain site closure at most complex sites. Thus, monitored natural attenuation (MNA) and enhanced attenuation (EA) have been widely accepted as alternatives because of their lower cost and sustainable management for large, complex plumes. However, the planning and evaluation of MNA/EA applications require greater levels of characterization data than typically collected. Advanced, innovative methods are required to characterize specific attenuation processes and associated rates to evaluate the feasibility of MNA/EA. Contaminant elution and tracer (CET) tests have been proposed as one such advanced method. Another objective of this study is to investigate the use of modified well-field configurations to enhance the performance of CET tests to collect critical site-specific data that can be used to better delineate attenuation processes and quantify the associated rate coefficients. Three-dimensional numerical models were used to simulate the CET test with specific well-field configurations under different conditions. The results show that the CET test with a nested (two-couplet) well-field configuration can be used to characterize transport and attenuation processes by eliminating the impact of the surrounding plume. The results also show that applying select analytical mass-removal functions can be an efficient method for parameter estimation, as it does not require the use of mathematical transport modeling and does not require the attendant input data that are costly and time-consuming to obtain.

Thesis (M.S.)--University of Kentucky, 2003.
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This thesis describes research conducted to evaluate the efficacy of the gas-phase partitioning tracer method for measuring bulk soil-water content. A series of tracer experiments were conducted at two velocities and water contents in a well instrumented weighing lysimeter. The method is based on introducing gas-phase conservative and water-partitioning tracers into the system. The partitioning tracer dissolves into the water, which retards its movement with respect to a non-partitioning tracer. This retardation is a function of the soil-water content. The soil-water contents estimated from comparative moment analyses of the measured breakthrough curves were compared to values obtained using traditional methods for determining soil-water content. These methods include: neutron thermalization, time domain reflectometry, gravimetric core analysis, and soil tension. The results from the tracer test compare favorably at different velocities and soil-water contents with the data provided by traditional methods. For the slower velocities, the tracer results yielded soil-water contents of 0.06 and 0.12 while the traditional methods 'indicated soil-water contents of 0.06 and 0.15. Tracer tests conducted at higher velocities yielded soil-water contents of 0.05 and 0.11 while traditional methods indicated soil-water contents of 0.06 and 0.15. This indicates that the water partitioning tracer method has potential to provide accurate results under a variety of conditions.

Les processus microbiens ont une importance déterminante dans la dynamique des processus réactifs dans les eaux souterraines. La compréhension de la variabilité spatiale et temporelle de ces phénomènes, et le développement de méthodes expérimentales de terrain, ouvrent de nouveaux champs de recherches et d'applications allant de la remédiation des aquifères contaminés à la compréhension des grands cycles biogéochimiques naturels. Dans le premier volet de cette thèse nous présentons des observations de terrain permettant de comprendre le rôle des fractures sur la formation d'un ''hotspot'' d'activité microbienne en profondeur. Du fait de leur forte réactivité, ces ''hotspots'' peuvent dominer la dynamique biogéochimique des milieux souterrains, malgré leur faible extension spatiale. Nous avons ainsi analyser les conditions de formation d'un tapis microbien par des bactéries ferro-oxydantes à 60 mètres de profondeur sur l'observatoire de Ploemeur (réseau H+) alors que ces phénomènes ont été observé jusqu'à présent en surface. Les résultats de cette étude montrent que des circulations hétérogènes, liées à la structure des milieux fracturés, créent des zones mélanges entre des eaux riches en fer et des eaux oxygénées, à l'origine de ce hotspot microbien. Le deuxième volet de ce travail de thèse a été consacré au développement d'une méthode innovante pour la mesure en continu de l'activité microbienne dans les eaux souterraines. La méthode est basée sur l'utilisation de la Fluoréscéine DiAcétate (FDA) dont le produit de réaction peut être mesuré en continu par un fluorimètre de terrain. Après avoir testé et validé les protocoles sur des solutions enzymatiques et des eaux naturelles en laboratoire, nous avons mis en œuvre cette technique sur le terrain au cours d'expériences de traçages réactifs. Un modèle cinétique nous a permis d'approcher les résultats obtenus en laboratoire, et de comparer nos résultats de terrain aux calibrations effectuées in vitro. Cette méthode ouvre ainsi de nouvelles perspectives pour la caractérisation des processus biogéochimiques sur le terrain
Microbial processes play a key role in controlling biogeochemical reactivity in groundwater. The understanding of the spatial and temporal variability of these phenomena and the development of novel experimental field methods, has opened new fields of research and applications, ranging from groundwater remediation to understanding of global biochemical cycles. In the first part of this thesis, we present field observations providing new insights on the role of fractures in the formation of a hotspot of microbial activity. Because of their large reactivity, these hotspots can dominate the biogeochemical dynamics of subsurface systems, despite their small spatial extent. We have thus analyzed the conditions for the formation of a microbial mat composed of iron-oxidizing bacteria at 60 meters depth in the Ploemeur fractured rock observatory (H+ network) while these phenomena are usually observed at the surface. These results show that heterogeneous flowpaths, linked to the structure of fractured media, create mixing zones between iron rich water and oxygen rich water, at the origin of the microbial hotspot. The second part of this work was devoted to the development of a novel method for a continuous measurement of microbial activity in groundwater. The method is based on the use of Fluorescein DiAcetate (FDA) whose product of reaction can be measured continuously by a field fluorimeter. After testing and validating protocols in the lab on enzymatic solutions and natural water, we have implemented this technic in the field in reactive tracer test experiments. A kinetic model allowed us to interpret the lab results, and to compare them to the field kinetics. This method thus opens new perspectives for the characterization of biogeochemical processes in the field

Les milieux cristallins fracturés constituent un potentiel géothermique non négligeable. Il est essentiel d'améliorer son exploitation, pour la géothermie basse et haute énergie, afin de répondre au processus de transition énergétique. Pour cela, la compréhension des mécanismes de transport thermique dans les milieux fracturés est fondamentale. Le transport de chaleur est fortement influencé par l'hétérogénéité hydrodynamique des milieux fracturés et par la géométrie des fractures et des blocs matriciels. A travers des travaux basés sur des développements analytiques et numériques ainsi que des expériences sur site, l'objectif de cette thèse est ainsi de mieux évaluer l'impact de la géométrie des fractures, que ce soit à l'échelle d'un réseau de fractures, ou à l’échelle d’une fracture, sur le transport et le stockage d’énergie thermique dans les milieux cristallins fracturés. Des simulations numériques du transport de chaleur dans un réseau simple de fractures planes et bien connectées ont permis de caractériser l'impact de la géométrie du système de fractures sur le stockage thermique. Deux régimes sont mis en évidence. Tout d'abord, à court terme, la densité de fractures ou de chemins préférentiels, caractérisant la surface d'échange, contrôle l'échange thermique. Puis, à long terme, c'est le volume de roche total entre les fractures qui contrôle le stockage thermique. Ce modèle ne prend toutefois pas en compte la variabilité des ouvertures à l'échelle de la fracture qui est particulièrement présente dans les réseaux de fractures naturels. Des tests de traçage thermique et de soluté ont ainsi été réalisés pour caractériser le transport de chaleur dans un milieu fracturé sur le site de Ploemeur (SNO H+). Pour interpréter les traçages, les expressions analytiques du retard et de l'amplitude du pic de la courbe de restitution thermique ont été développées pour différentes géométries de fractures : fractures planes et chenaux. Ces expressions constituent un outil puissant et novateur pour caractériser la géométrie des fractures lors de tests de traçage thermique mais aussi pour prédire le déplacement du front thermique et la durée de vie des systèmes géothermiques à partir de tests de traçage de soluté. La comparaison de ces expressions avec les résultats expérimentaux permet de mettre en évidence l'importante chenalisation des flux, induisant l'arrivée anticipée du traceur thermique
Fractured crystalline media has a significant geothermal potential. Its exploitation, for low and high enthalpy geothermal power generation, could be enhanced to satisfy the energy transition process. For this, understanding thermal transport processes in fractured media is fundamental. Heat transport is strongly influenced by hydrodynamics heterogeneity of fractured media and by fracture and matrix block geometry. Through analytical and numerical modelling and field site experiments, the aim of this thesis is thus to better assess the impact of fracture geometry on thermal transport and storage in fractured crystalline rock, at fracture and fracture network scale. Numerical simulations of heat transport in a simple network of well connected plane fractures allowed us to characterize the impact of the fracture system geometry on thermal storage. Two regimes are highlighted. First, at short term, the density of fractures, or preferential paths, controls heat exchanges. Then at long term, the total rock volume between the fractures controls thermal storage. This model does not take into account the aperture variability at fracture scale, which is particularly present in natural fracture networks. Thus, thermal and solute tracer tests have been achieved to characterize heat transport in a fractured media at Ploemeur field site (SNO H +). To interpret the tracer tests, analytical expressions of thermal breakthrough peak retardation and amplitude have been developed for different fracture geometries : parallel plate fractures and channels. Those expressions are a powerful and innovative tool to characterize fracture geometries from thermal tracer tests, and also to predict thermal front transit time and lifetime of geothermal systems from solute tracer tests. Confrontation of those expressions to experimental results shows that observed differences between thermal and solute breakthrough can be explained only by channeling flow inducing low thermal transit times

Single well forced gradient tracer tests are a potential cost-effective approach to estimate in situ aquifer contaminant fate and transport parameters for use in natural attenuation assessments and remediation schemes. To date dipole flow tracer tests have been used to measure the conservative and hydraulic parameters of an aquifer, while push-pull tests are well characterised for use with biodegrading tracers. The effect of typical aquifer physical heterogeneity on the ability of single well tests to successfully estimate parameters has not yet been characterised. Also, the ability of single well tests to accurately and quickly measure aquifer parameters using tracer mixtures should be analysed. To investigate the effect of physical heterogeneity on single well tests scaled down ultraviolet imaging experiments were performed in a low profile box. Potential tracers for use in mixtures were investigated through column and batch experiments: Inorganic anions and fluorescein, inorganic cations, acetate and trichlorofluoroethene were considered to measure conservative transport parameters, cation exchange capacity, biodegradation potential and hydrophobic sorption respectively. Numerical modelling was used to simulate reactive tracer signals in single well forced gradient tests. Results suggest that dipole flow tracer tests are appropriate for measuring conservative transport parameters and the sorption of lowly retarded tracers, but are not highly suitable for biodegrading tracers. Tests could be performed with non-recirculating flow, allowing simpler modelling, if equal injection and extraction flow rates could be ensured. Push-pull tests are suitable for biodegrading tracers and moderate to highly retarded tracers. This limits the potential to use reactive tracer mixtures in these tests. Dipole flow tracer test breakthrough curves are highly susceptible to heterogeneity, and could be used to identify discrete permeability variations in aquifers. The effect of heterogeneity is not significant on push-pull test breakthrough curves, but seriously affects tracer plume migration. Inorganic anions provided the most reliable conservative tracer. Trichlorofluoroethene was found to be a suitable tracer to measure hydrophobic sorption. The biodegradation surrogate chosen for a field test should biodegrade similarly to the contaminant under study.

La comprensione dei processi di ricarica, di movimento e di immagazzinamento delle acque sotterranee negli acquiferi carbonatici rappresenta una grande sfida per l’idrogeologia. Infatti, questi acquiferi sono ospitati in formazioni geologiche caratterizzate da forti eterogeneità e anisotropie che si possono ripercuotere nelle caratteristiche idrodinamiche del sistema. Questa comprensione diventa tanto più complicata quando si trattano acquiferi ricadenti in aree montuose, ove la complessità geologico-strutturale si unisce a una grande eterogeneità topografica. Quest’ultima può influenzare il regime pluviometrico in maniera significativa, ed inoltre le quote elevate sono spesso caratterizzate dalla presenza del manto nevoso che apporta un contributo non trascurabile ai processi di ricarica degli acquiferi. In questo contesto, è stato dimostrato che i terremoti ad elevata magnitudo possono cambiare il comportamento idrodinamico delle sorgenti mostrando variazioni transitorie o di lunga durata, rendendo la gestione della risorsa idrica molto impegnativa. Questo è il caso di una ampia zona Appenninica dell’Italia centrale, quella interessata da una intensa sequenza sismica tra agosto 2016 e gennaio 2017, caratterizzata da nove eventi di Mw ≥ 5.0 di cui il più forte di Mw = 6.5 con epicentro ubicato all’interno dell’area di studio. Questa ricerca incrementa notevolmente le conoscenze idrogeologiche ed idrodinamiche relative alla circolazione delle acque sotterranee negli acquiferi carbonatici, approfondendo i possibili cambiamenti delle caratteristiche qualitative e quantitative del flusso idrico sotterraneo, durante e dopo una serie di forti eventi sismici. È stato utilizzato un approccio olistico combinato coinvolgente diverse discipline e tecniche, a partire da un'indagine idrogeologica più tradizionale basata sull'applicazione del bilancio idrologico e sull'analisi degli idrogrammi delle portate sorgentizie, validata mediante i risultati di numerosi test con traccianti artificiali, e analisi geochimiche ed isotopiche. Durante le indagini è stato effettuato un rilevamento idrogeostrutturale di dettaglio, integrato con un'analisi basata su sistemi geografici informativi, finalizzato sia alla identificazione delle strutture geologiche principali responsabili del cambiamento del flusso idrico sotterraneo, sia alla caratterizzazione delle varie idrostrutture presenti nell'area in studio e dei rapporti tra esse. I risultati confermano la complessità geologico-strutturale di questa area e la ripercussione sull'assetto idrogeologico, evidenziando in particolare il ruolo che le faglie, ad estensione sia regionale che locale, giocano nelle modificazioni del flusso di acque sotterranee. Le evidenze ottenute da ciascuna tecnica di indagine sono state confrontate tra loro per delineare un modello idrogeologico concettuale indispensabile per la corretta e sostenibile gestione della risorsa idrica sotterranea.
Understanding the groundwater flow, recharge, and storage processes in carbonate aquifers represents a challenging aspect in hydrogeology. These aquifers are hosted in geological formations characterised by strong heterogeneities and anisotropies affecting the hydrodynamic characteristics of the systems. This comprehension becomes even more complicated when dealing with mountainous aquifers, where the geological and the geo-structural complexity is combined with high topographical heterogeneity. The topographical heterogeneity can significantly influence the rainfall regime, and the higher altitudes, often characterised by the presence of snow cover, make a non-negligible contribution to the aquifers' recharge processes. In this context, it has been demonstrated that high-magnitude earthquakes can change the hydrodynamic behaviour of springs and rivers showing transient or long-lasting hydrogeological modifications, making the water management a real hard task. This is the case of a wide Apennines area located in central Italy, the one affected by an intense seismic sequence between August 2016 and January 2017, characterized by nine events of Mw ≥ 5.0 (Mmax = 6.5) whose epicentre is located within the study area. This research aims to increase the hydrogeological and hydrodynamic knowledge related to groundwater circulation in carbonate aquifers by investigating possible changes in the qualitative and quantitative characteristics of groundwater flow, during and after a series of strong seismic events. A combined holistic approach, involving different disciplines and techniques, was used. The investigation starts with a more traditional hydrogeological approach, based on the application of the hydrological balance and the analysis of springs hydrographs, then validated through the results of several artificial tracer tests, hydrochemical and isotopic analyses. During the study, a detailed hydro-geo-structural survey was carried out, integrated with GIS-supported analysis, aimed both at identifying the main geological structures responsible for the groundwater flow modifications, and at characterising the hydrogeological connections between the hydrostructures recognised in the study area. The results of this research confirm the geo-structural complexity of the domain and its influence on the hydrogeological features, highlighting the role of faults, having a regional or local extension, played in modifying the groundwater flow. The outcomes obtained from each investigation technique had compared each other in order to outline a detailed conceptual hydrogeological model which has been updated step by step following the post-seismic phases to provide to the public and private drinking companies operating in the area, a tool for the correct and sustainable groundwater management operations.

Dans un contexte de restrictions budgétaires associées à des modifications de la réglementation concernant le stockage des sédiments fluviaux, il convient de prêter attention au comportement à la lixiviation des contaminants piégés dans les sédiments pendant le processus de stockage et la préparation des sédiments à la valorisation mise en place dans les installations de stockage. Afin de déterminer les mécanismes responsables de la mobilité des éléments contaminants et l’impact des conditions de stockage, l’étude a été axée sur trois scénarios de traitement des sédiments ainsi qu’une modélisation géochimique : Le premier scénario consiste à établir l’impact de l’aération et des traitements tels que le lagunage et le retournement mécanique sur la mobilité des éléments dans les sédiments fluviaux de curage via l’application de cycles d’humidification/séchage en lysimètre de laboratoire . Ce dispositif a permis de distinguer l'estimation d'une durée de traitement soit naturel sur plusieurs décennies soit améliorée via le retrait des eaux interstitielles. Le deuxième scénario a pour but d'évaluer l’évolution à court terme des sédiments à l’aide d’essais de conformité (lixiviation en batch, lixiviation de fonction du pH et lixiviation en colonne à percolation ascendante) mettant en évidence les modifications dans la mobilité et la spéciation des éléments traces. Le troisième scénario se place dans l’optique d’une voie de valorisation directe, les sédiments enrichis en matière organique semblent présenter une mobilité en éléments traces plus importante que celle observée dans les sédiments fluviaux et nécessitent donc un suivi environnemental poussé, plus particulièrement pour le Zn fortement représenté dans les sédiments étudiés. Enfin,la modélisation. Ceci a mis en évidence un rôle importante des oxydes de fer et de la matière organique dans la mobilité des éléments traces de même qu'un éclairage sur les phases solides en présence et pouvant se former en fonction des conditions du milieu
In a context of budgetary restrictions associated with changes in the regulation of river sediment storage, attention should be paid to the leaching behavior of sediment-trapped contaminants during the storage process and the preparation of sediments for valorization. In order to determine the mechanisms responsible for contaminant mobility and the impact of storage conditions, the study focused on three sediment treatment scenarios and geochemical modeling: (i) Determine the impact of aeration and treatments such as lagooning and mechanical reversal on the mobility of the trace elements in fluvial sediment by the application of humidification / drying cycles in a laboratory lysimeter. This has made it possible to distinguish the quality of the drainage water and the interstitial waters with a greater contamination, to conclude on the estimation of natural treatment duration over several decades which can be improved via a removal of interstitial waters. (ii) Assess the short-term evolution of sediments using compliance testing (batch leaching, pH leaching, and ascending percolation column leaching) highlighting changes in mobility and speciation trace elements. (iii) In the context of a direct valorization, sediments enriched with organic matter seem to have a greater mobility in trace elements than that observed in fluvial sediments and therefore require a strong environmental monitoring, more particularly for Zn strongly represented in the studies sediments. (iv) Modelling environmental conditions that are difficult to reproduce in laboratories. Thus, this has highlighted an important role of iron oxides and organic matter in the mobility of trace elements as well as illumination of the solid phases in the presence and which can be form depending on the environmental conditions

In this paper we examine, by Monte Carlo simulation, size and power of the Johansens trace test when the error covariance matrix is nonstationary, and we also investigate the properties of three different bootstrap cointegration tests. Earlier studies indicate that the Johansen trace test is not robust in presence of heteroscedasticity, and tests based on resampling methods have been proposed to solve the problem. The tests that are evaluated is the Johansen trace test, nonparametric bootstrap test and two different types of wild bootstrap tests. The wild bootstrap test is a resampling method that attempts to mimic the GARCH model by multiplying each residual by a stochastic variable with an expected value of zero and unit variance. The wild bootstrap tests proved to be superior to the other tests, but not as good as earlier indicated. The more the error terms differs from white noise, the worse these tests are doing. Although the wild bootstrap tests did not do a very bad job, the focus of further investigation should be to derive tests that does an even better job than the wild bootstrap tests examined here.

Over the last two decades research has shown that the different forms of trace elements in the environment can cause a variety of health concerns as a result of differences in toxicity. The need to establish efficient, effective and reliable speciation methods has become paramount. A basic aim of this work has been to advance speciation measurement capability for key trace elements (mercury, lead and chromium) by devising an integrated analytical approach that links the sample collection, sample preservation and laboratory measurements in an unified manner. An introductory chapter first reviews the occurrence of organometallic compounds in the environment and focuses on the identification of the "environmental compartments" where transformations of such species can take place. Speciation studies also assist in understanding the biogeochemical cycling of trace elements. Moreover, a review of the various methodologies used for trace element speciation measurements including hyphenated techniques and/or a variety of chemical/physical pretreatments in combination with flow injection (FI) is discussed. Chapter 2 describes mercury speciation experiments utilising gas chromatography-microwave induced plasma-atomic emission spectrometry (GC-MIP-AES) and FI. The approach was based on the preconcentration of mercury on sulphydryl cotton and after elution from the microcolumn, separation and quantitation of methyl-, ethyl- and inorganic mercury species. Method development experiments were performed using a derivatisation technique which gave low contamination and allowed rapid analysis of samples. The microcolumn technique was transferred to the field and speciation of mercury in surface waters of the Manchester Ship Canal was undertaken and high methylmercury concentrations (0.052-0.182 ug 1 -1, as Hg) were detected. In so doing the new approach offered the preservation of the natural speciation state of the water sample directly at the sampling site and during the interval between collection and analysis. In chapter 3 lead studies are centred on the development of a rapid speciation scheme for neutral and cationic (organic and inorganic) lead species based on activated alumina microcolumn separation in combination with ICP-MS and FI. The approach permitted rapid assessment of the nature of lead contamination in environmental waters. Speciation of lead in surface waters of the Manchester Ship Canal was also undertaken using the field sampling approach in an attempt to confirm a transmethyllation reaction between organolead and inorganic mercury. A further application for microcolumns, in the context of speciation measurement, is their use as external calibrants and certified reference materials (CRMs) and this is discussed in the penultimate chapter. Key elements were mercury and chromium. After immobilisation of mercury species on SCF microcolumns it was found that recoveries for methyl- and inorganic mercury were quantitative over 4 months in contrast to ethylmercury which was 2 months. Similar studies for chromium species indicated ineffective elution and more vigorous conditions (microwave assisted digestion) for the elution step were used. A final chapter reviews progress and recommendations are given concerning future research and application for microcolumn field sampling in combination with instrumental analytical techniques.

Regression testing is often a very resource and time consuming activity with large scale software. However, regression tests may be run in continuous integration where everything should run fast in order to get quick feedback. This thesis reviews the existing solutions to optimize regression test suites and test suites in general by looking at various existing heuristic, computational intelligence and other methods. In most cases, these methods are based on the fact that test suites may contain redundant test cases. They also require code coverage, fault detection capability or requirement coverage information of each test case in order to be implemented. Additionally, the thesis studies ways to detect redundancy in test trace. It is also discussed whether or not this kind of redundancy information can be used for test suite optimization instead. A new concept, pair-wise supermaximal repeats is presented. A case study is conducted in software component continuous integration testing environment in Nokia Networks. Main methods include looking for patterns in test trace manually in a plot representing the test trace as well as finding pair-wise supermaximal repeats in the test trace with an enhanced suffix array implementation developed in test driven development method. A new application was developed, MRS Finder. The repeats are then analyzed. The study shows that the there can be found huge amount of repetition which makes analyzing all of it hard by hand. The repeats also tend to occur more in the setup or teardown phase of a test case rather than in the action or assertion phase of the test cases. The study shows that MRS Finder offers different optimization possibilities than originally was thought
Regressiotestaus on usein hyvin resursseja ja aikaa kuluttavaa suurten ohjelmistojen kanssa. Regressiotestejä voidaan kuitenkin ajaa jatkuvassa integroinnissa, jossa senkin tulisi suoriutua nopeasti, jotta palauteaika pysyy lyhyenä. Tämä diplomityö käy läpi olemassa olevia ratkaisuja regressiotestien ja yleisestikin testisarjojen optimointia. Näistä käsitellään muun muassa heuristisia ja laskennallisen älykkyyden menetelmiä. Useimmissa tapauksissa nämä metodit perustuvat siihen, että testisarjat voivat sisältää testitapauksia, joissa on keskinäistä redundanssia. Menetelmät vaativat myös tietoa jokaisen testitapauksen koodikattavuudesta, virheiden paljastuskyvystä tai vaatimuskattavuudesta, jotta ne voidaan toteuttaa käytännössä. Tämä työ tutkii myös tapoja löytää redundanssia testien jäljistä. Työ pohtii, voitaisiinko tätä tietoa käyttää testisarjojen optimointiin edellä mainittujen tietojen sijaan. Tämä työ esittelee uuden käsitteen, parittaisen supermaksimaalisen toiston. Tapaustutkimus suoritettiin Nokia Networksin systeemikomponenttitason jatkuvan integroinnin järjestelmässä. Tapaustutkimuksessa kehitettiin testivetoisella kehityksellä MRS Finder -ohjelmisto, joka etsii toistoja parannetusta suffiksitaulusta ja tuottaa diagrammin, joka edustaa testien jälkiä. Diagrammista etsitään toistoja manuaalisesti ja suffiksitaulusta löydettyjä toistoja analysoidaan. Tutkimus näyttää, että testien jäljistä voidaan löytää suuri määrä toistoja, joka tekee analysoinnista vaikeaa käsin. Toistot esiintyvät useammin testi tapauksien alkuasetus (setup) ja poiskorjaus (teardown) -vaiheissa kuin toiminta- tai vakuutusvaiheissa (assertion). Tutkimus näyttää myös, että MRS Finderilla löydetään erilaisia testi tapauksien optimointimahdollisuuksia kuin aluksi ajateltiin

The CMS Tracker is an all silicon detector and it is the biggest of its kind to be built. The system consists of over 15,000 individual detector modules giving rise to readout through almost 107 channels. The data generated by the Tracker system is close to 650 MB at 40 MHz. This has created a challenge for the CMS collaborators in terms of data storage for analysis. To store only the interesting physics data the readout rate has to be reduced to 100 Hz where the data has to be ltered through a monitoring system for quality checks. The Tracker being the closest part of the detector to the interaction point of the CMS creates yet another challenge that needs the data quality monitoring system. As it operates in a very hostile environment the silicon detectors used to detect the particles will be degraded. It is very important to monitor the changes in the sensor behaviour with time so that to calibrate the sensors to compensate for the erroneous readings. This thesis discusses the development of a monitoring system that will enable the checking of data generated by the tracker to address the issues discussed above. The system has two parts, one dealing with the data used to monitor the Tracker and a second one that deals with statistical methods used to check the quality of the data.

Research on the electrocoagulation (EC) of hexane extractable materials (HEM) has been conducted at the University of New Orleans using a proprietary bench-scale EC reactor. The original reactor configuration forced the fluid to follow a vertical upward-downward path. An alternate electrode arrangement was introduced so that the path of flow became horizontal. Both configurations were evaluated by comparing the residence time distribution (RTD) data generated in each case. These data produced indication of internal recirculation and stagnant water when the fluid followed a vertical path. These anomalies were attenuated when the fluid flowed horizontally and at a velocity higher than 0.032 m s-1 . A series of EC experiments were performed using a synthetic emulsion with a HEM concentration of approximately 700 mg l-1. It was confirmed that EC of HEM follows first-order kinetics, and kinetic constants of 0.0441 s-1 and 0.0443 s-1 were obtained from applying both the dispersion and tanks-in-series (TIS) models, respectively. In both cases R2 was 0.97. Also, the TIS model indicated that each cell of the EC behaves as an independent continuous-stirred-tank reactor.

Down-hole injection and sampling equipment was designed and constructed in order to perform diverging-flow tracer tests. The tests were conducted at a field site about 8 km southeast of Oracle, Arizona, as part of a project sponsored by the U. S. Nuclear Regulatory Commission to study mass transport of fluids in saturated, fractured granite. The tracer injection system was designed to provide a steady flow of water or tracer solution to a packed off interval of the borehole and allow for monitoring of down-hole tracer concentration and pressure in the injection interval. The sampling system was designed to collect small volume samples from multiple points in an adjacent borehole. Field operation of the equipment demonstrated the importance of prior knowledge of the location of interconnecting fractures before tracer testing and the need for down-hole mixing of the tracer solution in the injection interval. The field tests were designed to provide data that could me analyzed to provide estimates of dispersivity and porosity of the fractured rock. Although analysis of the data is beyond the scope of this thesis, the detailed data are presented in four appendices.

A computer model is extended and applied to analyze divergent flow tracer test data from a field experiment near Oracle, Arizona. The model can accommodate a pulse, step increase, and an arbitrary distribution of injection concentration with respect to time. The model is tested against three analytical solutions and is subjected to sensitivity analyses. The model is free of numerical dispersion with proper grid spacing and location of the external boundary. Analysis of field data using the model involves a curve matching procedure. An equivalent radial flow field is used to account for non-radial flow conditions by adjusting the flow rate and the mass that enters the flow field. Application of the model to field data yields a longitudinal dispersivity of 5.08 meters and a product of effective porosity and thickness of 0.009 meters. Since the test was not conducted under strict flow conditions, the above results are considered tentative.

Post-Silicon validation is playing an increasingly important role as more chips are failing in the functional mode due to either manufacturing defects escaped during scan-based tests or design bugs missed during pre-silicon validation. Critical to the diagnosis engineer is the ability to observe as many relevant internal signal values as possible during debug. To do so, trace buffers have been proposed for enhancing the observability of internal signals during post-silicon debug. Trace Buffers are used to trace (record the values of) the internal signals in real-time when chip is in its normal operation. However, existing trace buffer architectures trace very few signals for a large number of cycles. Thus, even with a good subset of signals traced, one often still cannot restore all the relevant values in the circuit. In this work, we propose two different flexible trace buffer architectures that can restore the values for all signals by making the trace signals configurable. In addition, the buffer space can also be shared among different traced signals which makes the architectures highly flexible. As compared to conventional trace buffer architectures, the new architectures have comparable area overhead but offer the ability to restore all signals in the circuit. For cases of less than 100% restoration, the ability of circuit invariants to improve the signal restoration is explored. A promising direction for the future work is provided where targeted invariants may lead to better restoration scenario during post-silicon validation.
Master of Science