Infrared Thermography Enhancements for Concrete Bridge Evaluation

Infrared thermography is a well-recognized non-destructive testing technique for evaluating concrete bridge elements such as bridge decks and piers. However, overcoming some obstacles and limitations are necessary to be able to add this invaluable technique to the bridge inspector's tool box. Infrared thermography is based on collecting radiant temperature and presenting the results as a thermal infrared image. Two methods considered in conducting an infrared thermography test include passive and active. The source of heat is the main difference between these two approaches of infrared thermography testing. Solar energy and ambient temperature change are the main heat sources in conducting a passive infrared thermography test, while active infrared thermography involves generating a temperature gradient using an external source of heat other than sun. Passive infrared thermography testing was conducted on three concrete bridge decks in Michigan. Ground truth information was gathered through coring several locations on each bridge deck to validate the results obtained from the passive infrared thermography test. Challenges associated with data collection and processing using passive infrared thermography are discussed and provide additional evidence to confirm that passive infrared thermography is a promising remote sensing tool for bridge inspections. To improve the capabilities of the infrared thermography technique for evaluation of the underside of bridge decks and bridge girders, an active infrared thermography technique using the surface heating method was developed in the laboratory on five concrete slabs with simulated delaminations. Results from this study demonstrated that active infrared thermography not only eliminates some limitations associated with passive infrared thermography, but also provides information regarding the depth of the delaminations. Active infrared thermography was conducted on a segment of an out-of-service prestressed box beam and cores were extracted from several locations on the beam to validate the results. This study confirms the feasibility of the application of active infrared thermography on concrete bridges and of estimating the size and depth of delaminations. From the results gathered in this dissertation, it was established that applying both passive and active thermography can provide transportation agencies with qualitative and quantitative measures for efficient maintenance and repair decision-making.

Spray characterization under flash boiling conditions of a DI multi-hole injector at high injection pressures in a combustion vessel

Spray characterization under flash boiling conditions was investigated utilizing a symmetric multi-hole injector applicable to the gasoline direct injection (GDI) engine. Tests were performed in a constant volume combustion vessel using a high-speed schlieren and Mie scattering imaging systems. Four fuels including n-heptane, 100% ethanol, pure ethanol blended with 15% iso-octane by volume, and test grade E85 were considered in the study. Experimental conditions included various ambient pressure, fuel temperature, and fuel injection pressure. Visualization of the vaporizing spray development was acquired by utilizing schlieren and laser-based Mie scattering techniques. Time evolved spray tip penetration, spray angle, and the ratio of the vapor to liquid region were analyzed by utilizing digital image processing techniques in MATLAB. This research outlines spray characteristics at flash boiling and non-flash boiling conditions. At flash boiling conditions it was observed that individual plumes merge together, leading to significant contraction in spray angle as compared to non-flash boiling conditions. The results indicate that at flash boiling conditions, spray formation and expansion of vapor region is dependent on momentum exchange offered by the ambient gas. A relation between momentum exchange and liquid spray angle formed was also observed.

Fish contaminants through the tribal perspective : an ethnography of the Keweenaw Bay Indian Community's tribal fish harvest

It has been well documented that many tribal populations and minority groups across the nation have been identified as being at high risk of the adverse health effects created by consuming fish that have been contaminated with mercury, PCBs, DDT, dioxins, and other chemicals. Although fish consumption advisories are intended to inform fish consumers of risks associated with specific species and water bodies, advisories have been the subject of both environmental injustices and treaty rights’ injustices. This means that understanding fish contaminants, through community perspectives is essential to good environmental policy. This study examined the fish contaminant knowledge, impacts on fishing and fish consumption, and the factors that contribute to harvesting decisions and behaviors in one tribal nation in the Upper Peninsula of Michigan, the Keweenaw Bay Indian Community. Using ethnographic methods, participant observation and semi-structured interviewing, fieldnotes were kept and all interviews were fully transcribed for data analysis. Among seventeen fishermen and women, contaminants are poorly understood, have had a limited impact on subsistence fishing but have had a substantial impact on commercial fishing activity. But ultimately, all decisions and behaviors are based on their own criteria and within a larger context of knowledge and understanding: the historical and cultural context. The historical context revealed that advisories are viewed as another attack on tribal fishing. The cultural context revealed that it is the fundamental guidance and essential framework associated with all harvesting beliefs, values, and traditional lifeways. These results have implications for advisories. ‘Fish’ and ‘contaminants’ appear differently based on the perceptions and priorities of those who encounter them.

MATURE FINE TAILINGS (MFTs): A STUDY OF COMPRESSIVE STRENGTH AND RHEOLOGICAL PROPERTIES OF ATHABASCA OIL SANDS PETROLEUM MINING WASTE APPLIED IN CONCRETE MIXTURES

This study investigates the compressive properties of concrete incorporating Mature Fine Tailings (MFTs) waste stream from a tar sands mining operation. The objectives of this study are to investigate material properties of the MFT material itself, as well as establish general feasibility of the utilization of MFT material in concrete mixtures through empirical data and visual observations. Investigations undertaken in this study consist of moisture content, materials finer than No. 200 sieve, Atterburg Limits as well as visual observations performed on MFT material as obtained. Control concrete mixtures as well as MFT replacement mixture designs (% by wt. of water) were guided by properties of the MFT material that were experimentally established. The experimental design consists of compression testing of 4”-diameter concrete cylinders of a control mixture, 30% MFT, 50% MFT and 70% MFT replacement mixtures with air-entrainer additive, as well as a control mixture and 30% MFT replacement mixture with no air-entrainer. A total of 6 mixtures (2 control mixtures, 4 replacement mixtures) moist-cured in lime water after 24 hours initial curing were tested for ultimate compressive strength at 7 days and 28 days in accordance to ASTM C39. The test results of fresh concrete material show that the addition of air-entrainer to the control mixture increases slump from 4” to 5.5”. However, the use of MFT material in concrete mixtures significantly decreases slump as compared to controls. All MFT replacement mixtures (30%, 50%, and 70%) with air-entrainer present slumps of 1”. 30% MFT with no air-entrainer presents a slump of 1.5”. It was found that 7-day ultimate compressive stress was not a good predictor of 28-day ultimate compressive stress. 28-day results indicate that the use of MFT material in concrete with air-entrainer decreases ultimate compressive stress for 30%, 50% and 70% MFT replacement amounts by 14.2%, 17.3% and 25.1% respectively.

Soft Lewis acid catalyzed cycloisomerization of oxo-alkynes and enynes

In the literature, some transition metal salts have been used as soft Lewis acids to activate alkynes toward nucleophilic attack. For example, Pt(II), Au(I) and Pd(II) catalysts can catalyze cycloisomerization reactions of alkynyl compounds to give a variety of cyclic products. In order to expand the scope of these reactions, in chapter 2 of this dissertation, several alkynyl epoxides were isomerized to cyclic allyl vinyl ethers using PtCl2 as the catalyst. Three of these allyl vinyl ethers were hydrolyzed to 2-hydroxymorpholine derivatives and two were converted to piperidine derivatives by thermal Claisen rearrangement. In order to find more benign and inexpensive catalysts for these types of reactions, in chapter 3 of this dissertation, BiCl3 was used to catalyze the isomerization of eight enynes to pyrrolidine derivatives. This reaction was normally catalyzed by expensive noble metal catalysts, such as Pd(II), Pt(II) and Au(I). All the cyclic products are valuable intermediates in the synthesis of bioactive molecules, these soft Lewis acid catalyzed cycloisomerization may find applications in the synthesis of bioactive molecules.

SO2 emissions at Volcan de Colima, 2003-2007

Volcán de Colima has been continuously erupting since the onset of dome growth in 1998. This period of unrest has had 4 prominent periods; 1998-1999, 2003, 2004-2005, and the current dome growth that began in February of 2007. Each of these episodes was marked by lava extrusion forming a dome and lava flows, followed by explosions that destroyed the dome. The Correlation Spectrometer (COSPEC) was used to determine SO2 emission rates on 164 days from May 2003 to February 2007, using both stationary ground based scans and some flight traverses. Scans were separated into the categories of explosive degassing and passive, or background degassing. These scans show variation in the SO2 flow rate from below detection limit (~3 t/d depending on environmental conditions) during background, passive emissions to a peak of 2949 t/d (34 kilograms/second) during an explosion on 9 October, 2004. Both passive and explosive degassing increased when there was lava extrusion in 2004 and with the increased explosive activity in 2005. These two different processes of degassing wax with each other when activity increases and wane together as well, indicating a parallel cyclicity in the volcanic eruption and degassing rates, where the conduit partially seals (pressurizes) between explosions. Colima’s gas and eruptive behavior is compared to similar systems such as Santiaguito and Soufrière Hills, Montserrat. About 2/3 of Colima’s SO2 degassing, amounting to 1.3 x 105 tonnes in 3.74 yrs has come in short lived small (VEI=0-1) vertical explosions that occurred at the rate of 100-3000explosions/ month, and the remaining third has occured in continuous passive degassing. Colima emits sulfur at a rate equivalent to about 0.04 to 0.08 wt % S, similar to other andesitic convergent plate boundary volcanoes. There has been an explosive destruction of the dome in every cycle for that past 5 years, and it is assumed that the current dome which began growth in February, 2007 (just at the end of this study) will be destroyed. Higher emission rates seen in the quiescence of 2006 may have eased the pressure at the time, resulting in the slow effusion of the current dome and lack of explosivity.

Synthesis, structure, and stability of metal-organic frameworks

Metal-organic frameworks (MOFs) obtained much attention because of their unusual structures and properties as well as their potential applications. This dissertation research was focused on (1) the effects of synthesis conditions on the structures of MOFs, (2) the thermal stability of MOFs, (3) pressure-induced amorphization, and (4) the effect of high-valent ions on the structure of a MOF. This research demonstrated that the crystal structure of MOF-5 could be controlled by drying solvents. If the vacuum solvent is dimethylformamide (DMF), the crystal structure of MOF-5 is tetragonal. In contrast, if the DMF is displaced by CH2Cl2 before the vacuum, the obtained MOF-5 occupies a cubic structure. Furthermore, it was found that the tetragonal MOF-5 exhibited a mediate surface area (300-1000 m2/g). The surface area of tetragonal MOF-5 is also dependent on Zn(NO3)2/H2BDC (H2BDC: terephthalic acid) molar ratios used for its synthesis. The optimum ratio is 1.38, at which synthesized tetragonal MOF-5 exhibits the highest crystallinity and surface area (1297 m2/g). The thermal stability and decomposition of MOF-5 were systematically investigated. The thermal decomposition of cubic and tetragonal MOF-5s resulted in the same products: CO2, benzene, amorphous carbon, and crystal ZnO. The thermal decomposition is due to breaking carboxylic bridges between benzene rings and Zn4O clusters. Identifying structural relationships between crystalline and noncrystalline states is of fundamental interest in materials research. Currently, amorphization of solid materials at ambient temperature requires an ultra-high pressure (several GPa). However, this research demonstrated that MOF-5 and IRMOF-8 can be irreversibly amorphized at ambient temperature by employing a low compressing pressure of 3.5 MPa, which is 100 times lower than that required for amorphization of other solids. Furthermore, the pressure-induced amorphization (PIA) of MOFs is strongly dependent on the changeability of bond angles. If the geometric structure of a MOF can allow bond angles to be changed without breaking bonds, it can easily be amorphized by compression. This can explain why MOF-5 and IRMOF-8 can easily be amorphized via compression than Cu-BTC. It is generally recognized that zeolitic imidazolate frameworks (ZIFs) occupy much higher stability than other types of MOFs. The representative of ZIFs is Zn(2-methylimidazole)2 (ZIF-8) exhibiting high-decomposition temperature and high chemical resistance to various solvents. However, so far, it is still unknown whether the high stability of ZIF-8 can be challenged by ions, which is important for its modification by doping ions. In this research, we performed aqueous salt solution treatment on ZIF-8, and the results showed that anions (Cl¯ and NO3¯) in a solution exhibited no effect on the crystal structure of ZIF-8. However, the effect of cations (in a solution) on structure of ZIF-8 strongly depends on the cation valences. The univalent metal cations showed no effect on the structure of ZIF-8, whereas the bivalent or higher-valent metal cations caused the collapse of ZIF-8 crystal structure. Therefore, structure stability of ZIF-8 is considered when it is subjected to the application, in which high-valent metal cations are involved.

QUADRUPOLE LEVITATION OF PARTICLES IN A THERMODYNAMICALLY REALISTIC CLOUD ENVIRONMENT

Understanding clouds and their role in climate depends in part on our ability to understand how individual cloud particles respond to environmental conditions. Keeping this objective in mind, a quadrupole trap with thermodynamic control has been designed and constructed in order to create an environment conducive to studying clouds in the laboratory. The quadrupole trap allows a single cloud particle to be suspended for long times. The temperature and water vapor saturation ratio near the trapped particle is controlled by the flow of saturated air through a tube with a discontinuous wall temperature. The design has the unique aspect that the quadrupole electrodes are submerged in heat transfer fluid, completely isolated from the cylindrical levitation volume. This fluid is used in the thermodynamic system to cool the chamber to realistic cloud temperatures, and a heated section of the tube provides for the temperature discontinuity. Thus far, charged water droplets, ranging from about 30-70 microns in diameter have been levitated. In addition, the thermodynamic system has been shown to create the necessary thermal conditions that will create supersaturated conditions in subsequent experiments. These advances will help lead to the next generation of ice nucleation experiments, moving from hemispherical droplets on a substrate to a spherical droplet that is not in contact with any surface.

Syntheses and characterization of monomeric Mo(VI) complexes with bidentate phosphine oxide ligands and dimeric and tetrameric Mo(V) clusters with benzoic acid and phosphinic acid derivatives, containing MoO2, Mo2O2(μ-O)2 and Mo4O4(μ3-O)4

Mo(VI) oxo complexes have been persistently sought after as epoxidation catalysts. Further, Mo(V) oxo clusters of the form M4(µ3-X)4 (M = transition metal, X = O, S) have been rigorously studied due to their remarkable structures and also their usefulness as models for electronic studies. The syntheses and characterizations of new Mo(VI) and Mo(V) oxo complexes have been described in this dissertation. Two new complexes MoO2Cl2Ph2P(O)CH2COOH and MoO2Cl2Ph2P(O)C6H4tBuS(O) were synthesized from reactions of “MoO2Cl2” with ligands Ph2P(O)CH2COOH and Ph2P(O)C6H4tBuS(O). Tetrameric packing arrangements comprised of hydrogen bonds were obtained for the complex MoO2Cl2Ph2P(O)CH2COOH and the ligand Ph2P(O)CH2COOH. Further the stability of an Mo-O bond was preferred over the Mo-S bond even though this resulted in the formation of a more strained seven membered ring. Tetranuclear Mo(V) complexes of the form [Mo4(µ3-O)4(µ-O2PR2)4O4], (PR2 = PPh2, PMe2) were synthesized using reactions of MoO2(acac)2 with diphenyl and dimethyl phosphinic acids, in ethanol. In the crystal structure of these complexes four Mo=O units are interconnected by four triply bridging oxygen atoms and bridging phosphinate ligands. The complex exhibited fourfold symmetry as evidenced by a single 31P NMR peak for the P atoms in the coordinated ligands. Reaction of WO2(acac)2 with Ph2POOH in methanol resulted in a dimeric W(VI) complex [(CH3O)2(O)W(µ-O)( µ-O2PPh2)2W(O)(CH3O)2] which contained a packing disorder in its crystal structure. Similar reactions of MoO2(acac)2 with benzoic acid derivatives resulted in dimeric complexes of the form [Mo2O2(acac)2(µ-O)(µ-OC2H5)(µ-O2CR)] (R = C6H5, (o-OH)C6H4, (p-Cl)C6H4, (2,4-(OH)2)C6H3, (o-I)C6H4) and one tetrameric complex [Mo2O2(acac)2(µ-O)(µ-OC2H5)(µ-O2C)C6H4(p-µ-O2C)Mo2O2(acac)2(µ-O)(µ-OC2H5)] with terephthalic acid. 1H NMR proved very useful in the prediction of the formation of dimers with the substituted benzoic acids, which were also confirmed by elemental analyses. The reductive capability of ethanol proved instrumental in the syntheses of Mo(V) tetrameric and dimeric clusters. Synthetic details, IR, 1H and 31P NMR spectroscopy and elemental analyses are reported for all new complexes. Further, single crystal X-ray structures of MoO2Cl2Ph2P(O)CH2COOH, MoO2Cl2Ph2P(O)C6H4tBuS(O), [Mo4(µ3-O)4(µ-O2PR2)4O4], (PR2 = PPh2, PMe2), [(CH3O)2(O)W(µ-O)( µ-O2PPh2)2W(O)(CH3O)2] and [Mo2O2(acac)2(µ-O)(µ-OC2H5)(µ-O2CR)] (R = C6H5, (o-OH)C6H4) are also presented.

Stability analysis of a mono inverter dual sensorless motors system

When a single brush-less dc motor is fed by an inverter with a sensor-less algorithm embedded in the switching controller, the system exhibits a linear and stable output in terms of the speed and torque. However, with two motors modulated by the same inverter, the system is unstable and rendered useless for a steady application, unless provided with some resistive damping on the supply lines. The project discusses and analysis the stability of such a system through simulations and hardware demonstrations and also will discuss a method to derive the values of these damping.

Comparison of three methods for driven pile capacity

A significant cost for foundations is the design and installation of piles when they are required due to poor ground conditions. Not only is it important that piles be designed properly, but also that the installation equipment and total cost be evaluated. To assist in the evaluation of piles a number of methods have been developed. In this research three of these methods were investigated, which were developed by the Federal Highway Administration, the US Corps of Engineers and the American Petroleum Institute (API). The results from these methods were entered into the program GRLWEAPTM to assess the pile drivability and to provide a standard base for comparing the three methods. An additional element of this research was to develop EXCEL spreadsheets to implement these three methods. Currently the Army Corps and API methods do not have publicly available software and must be performed manually, which requires that data is taken off of figures and tables, which can introduce error in the prediction of pile capacities. Following development of the EXCEL spreadsheet, they were validated with both manual calculations and existing data sets to ensure that the data output is correct. To evaluate the three pile capacity methods data was utilized from four project sites from North America. The data included site geotechnical data along with field determined pile capacities. In order to achieve a standard comparison of the data, the pile capacities and geotechnical data from the three methods were entered into GRLWEAPTM. The sites consisted of both cohesive and cohesionless soils; where one site was primarily cohesive, one was primarily cohesionless, and the other two consisted of inter-bedded cohesive and cohesionless soils. Based on this limited set of data the results indicated that the US Corps of Engineers method more closely compared with the field test data, followed by the API method to a lesser degree. The DRIVEN program compared favorably in cohesive soils, but over predicted in cohesionless material.

STATISTICAL METHODS FOR RARE AND COMMON VARIANT ASSOCIATION STUDIES

Complex human diseases are a major challenge for biological research. The goal of my research is to develop effective methods for biostatistics in order to create more opportunities for the prevention and cure of human diseases. This dissertation proposes statistical technologies that have the ability of being adapted to sequencing data in family-based designs, and that account for joint effects as well as gene-gene and gene-environment interactions in the GWA studies. The framework includes statistical methods for rare and common variant association studies. Although next-generation DNA sequencing technologies have made rare variant association studies feasible, the development of powerful statistical methods for rare variant association studies is still underway. Chapter 2 demonstrates two adaptive weighting methods for rare variant association studies based on family data for quantitative traits. The results show that both proposed methods are robust to population stratification, robust to the direction and magnitude of the effects of causal variants, and more powerful than the methods using weights suggested by Madsen and Browning [2009]. In Chapter 3, I extended the previously proposed test for Testing the effect of an Optimally Weighted combination of variants (TOW) [Sha et al., 2012] for unrelated individuals to TOW &ndash F, TOW for Family &ndash based design. Simulation results show that TOW &ndash F can control for population stratification in wide range of population structures including spatially structured populations, is robust to the directions of effect of causal variants, and is relatively robust to percentage of neutral variants. In GWA studies, this dissertation consists of a two &ndash locus joint effect analysis and a two-stage approach accounting for gene &ndash gene and gene &ndash environment interaction. Chapter 4 proposes a novel two &ndash stage approach, which is promising to identify joint effects, especially for monotonic models. The proposed approach outperforms a single &ndash marker method and a regular two &ndash stage analysis based on the two &ndash locus genotypic test. In Chapter 5, I proposed a gene &ndash based two &ndash stage approach to identify gene &ndash gene and gene &ndash environment interactions in GWA studies which can include rare variants. The two &ndash stage approach is applied to the GAW 17 dataset to identify the interaction between KDR gene and smoking status.

SPATIAL UNDERSTANDING OF MATRIX INVERSION FOR INVERSE FORCE ESTIMATION

A basic approach to study a NVH problem is to break down the system in three basic elements – source, path and receiver. While the receiver (response) and the transfer path can be measured, it is difficult to measure the source (forces) acting on the system. It becomes necessary to predict these forces to know how they influence the responses. This requires inverting the transfer path. Singular Value Decomposition (SVD) method is used to decompose the transfer path matrix into its principle components which is required for the inversion. The usual approach to force prediction requires rejecting the small singular values obtained during SVD by setting a threshold, as these small values dominate the inverse matrix. This assumption of the threshold may be subjected to rejecting important singular values severely affecting force prediction. The new approach discussed in this report looks at the column space of the transfer path matrix which is the basis for the predicted response. The response participation is an indication of how the small singular values influence the force participation. The ability to accurately reconstruct the response vector is important to establish a confidence in force vector prediction. The goal of this report is to suggest a solution that is mathematically feasible, physically meaningful, and numerically more efficient through examples. This understanding adds new insight to the effects of current code and how to apply algorithms and understanding to new codes.

Speciation with gene-flow in eastern North American red oaks (Quercus section Lobatae)

As foundational species, oaks (Quercus : Fagaceae) support the activities of both humans and wildlife. However, many oaks in North America are declining, a crisis exacerbated by the previous disappearance of other hard mast-producing trees. In addition, the economic demands placed on this drought-tolerant group may intensify if climate change extirpates other, relatively mesophytic species. Genetic tools can help address these management challenges. To this end, we developed a suite of 27 microsatellite markers, of which 22 are derived from expressed sequence tags (ESTs). Many of these markers bear significant homology to known genes and may be able to directly assay functional genetic variation. Markers obtained from enriched microsatellite libraries, on the other hand, are typically located in heterochromatic regions and should reflect demographic processes. Considered jointly, genic and genomic microsatellites can elucidate patterns of gene-flow and natural selection, which are fundamental to both an organism's evolutionary ecology and conservation biology. To this end, we employed the developed markers in an FST-based genome scan to detect the signature of divergent selection among the red oaks (Quercus section Lobatae). Three candidate genes with putative roles in stress responses demonstrated patterns of diversity consistent with adaptation to heterogeneous selective pressures. These genes may be important in both local genetic adaptation within species and divergence among them. Next, we used an isolation-with-migration model to quantify levels of gene-flow among four red oaks species during speciation. Both speciation in allopatry and speciation with gene-flow were found to be major drivers of red oak biodiversity. Loci playing a key role in speciation are also likely to be ecologically important within species

IS THE U.S. SHALE GAS BOOM HAVING AN EFFECT ON THE EUROPEAN GAS MARKET?

This thesis focuses on the impact of the American shale gas boom on the European natural gas market. The study presents different tests in order to analyze the dynamics of natural gas prices in the U.S., U.K. and German natural gas market. The question of cointegration between these different markets are analyzed using several tests. More specifically, the ADF tests for the presence of a unit root. The error correction model test and the Johansen cointegration procedure are applied in order to accept or reject the hypothesis of an integrated market. The results suggest no evidence of cointegration between these markets. There currently is no evidence of an impact of the U.S. shale gas boom on the European market.