Emotionally Focused Couple Therapy (EFT; Johnson, 2004) is an empirically validated approach to couple therapy that uses attachment theory to understand the needs and emotions of romantic partners. In EFT, relationship distress is conceptualized as resulting from negative affect, emotional disconnection, and unmet attachment needs. Although EFT is recognized as one of the most researched and effective approaches to couple therapy, little research has examined theoretically related characteristics of couples to changes in marital satisfaction throughout EFT. The present doctoral thesis examined this area of literature. Thirty-two couples were provided approximately 21 sessions of EFT. The goal of the first study was to identify intake characteristics related to change in marital satisfaction over the course of EFT. Couples completed self-report measures of marital satisfaction, attachment security, relationship trust, and emotional control at pre- and post-therapy and after each therapy session. Individuals higher on self-report attachment anxiety and higher levels of emotional control had greater change in marital satisfaction over the course of EFT. The goal of the second study was to examine intake levels of attachment security and its relationship to the occurrence of the blamer-softening event, a key change event in EFT, and changes in marital satisfaction. Results indicated that the occurrence of a blamer-softening event significantly predicted positive changes in marital satisfaction. Results also suggested that the occurrence of a softening event significantly moderated the relationship between attachment avoidance at intake and change in marital satisfaction from pre- to post-therapy. For couples who completed a blamer-softening event, partners with lower levels of attachment avoidance were more likely to have positive changes in marital satisfaction. However, this relationship was not evident for attachment anxiety. Overall, results from this thesis suggest that attachment security is a key characteristic of couple partners for therapists to consider when implementing EFT. Therapists may benefit from assessing attachment security at the start of therapy to help inform them of the emotion regulating strategies used by couple partners. This information may help therapists to tailor specific interventions such that couples may begin to develop more secure attachment bonds.

The main purpose of this thesis is to improve the fundamental knowledge of non-isothermal tempering of martensite phase and its effects on the reduction in hardness (softening) with respect the base metal occurring at the heat affected zone (HAZ) of resistance spot welded dual-phase (DP) steels. This thesis also aims at understanding the influence of HAZ-softening on the joint performance of various DP steel grades. The tempering of martensite occurring at the sub-critical HAZ (SC-HAZ) of resistance spot welded DP600, DP780 and DP980 steels has been systematically evaluated by microhardness testing through Vickers indentation and the degree of tempering has been correlated to the HAZ-softening. From the joint performance analysis of similar and dissimilar steel grade combinations assessed through standardized testing methods, three important issues have been targeted: a) the joint strength (maximum load to failure), b) the location of failure (failure mode), and c) the physical characteristic of the weld that determines certain type of failure (weld nugget size). In addition, a partial tensile test has been conducted in order to evaluate the initiation of failure in dissimilar steel grade combinations. It has been shown that HAZ-softening lowered the weld size at which transition from interfacial to pullout failure mode takes place along with increased load-bearing capacity and higher energy absorption. Thus, it is concluded from mechanical testing that HAZ-softening benefits the lap-shear tensile joint performance of resistance spot welded DP steels by facilitating pullout failures through failure initiation at the SC-HAZ (tempered region). Instrumented nanoindentation testing was employed to further investigate HAZ-softening along the SC-HAZ by evaluating individual phases of ferrite matrix and tempered martensite islands. Although the ferrite matrix presented a slight reduction in hardness at nanoscale, higher reduction in hardness (softening) resulted for tempered martensite; thus confirming that tempered martensite is the major contributor to softening at micro-scale. A comparison between nanohardness and microhardness testing made at different distances from the line of lower critical temperature of transformation (Ac1) allowed revealing the actual extension of the SC-HAZ. In this regard, good correlation was obtained between nanohardness results along the SC-HAZ and the microstructural changes analyzed by electron microscopy (i.e., the tempering of martensite occurring at various distances far from Ac1 was correlated to low temperature tempering of dual phase steels). An in-depth analysis of the tempering of martensite phase at high temperature in DP steel subjected non-isothermal conditions i.e., rapid heating, extremely short time at peak temperature and rapid cooling (resistance spot welding), has been carried out mainly through analytical transmission electron microscopy (TEM). In addition, an isothermal tempering condition (i.e., slow heating and long time at peak temperature) in DP steel has been evaluated for complementing the analysis. Both non-isothermal and isothermal conditions have been correlated to the softening behaviour. TEM analysis of the base metal in the DP steel indicated that the morphology of the martensite phase is dependent on its carbon content, and its tempering characteristics are similar to that of equal carbon containing martensitic steel. The isothermally tempered structure is characterized by coarsening and spheroidization of cementite (θ) and complete recovery of the martensite laths; whereas precipitation of fine quasi-spherical intralath θ-carbides, coarser plate-like interlath θ-carbides, decomposition of retained austenite into elongated θ-carbides, and partial recovery of the lath structure were observed after non-isothermal tempering of DP steel. This difference in tempering behaviour is attributed to synergistic effect of delay in cementite precipitation due to higher heating rate, and insufficient time for diffusion of carbon that delays the third stage of tempering process (cementite coarsening and recrystalization) during non-isothermal. The finer size and the plate-like morphology of the precipitated carbides along with the partial recovery of the lath structure observed after non-isothermal tempering strongly influenced the softening behaviour of DP steel. The chemical analysis of θ-carbides through extraction replicas for three different DP steels revealed that the chemistry of the carbides is inherited from the parent DP steel during non-isothermal tempering at high temperature confirming that non-isothermal tempering DP steel is predominantly controlled by carbon diffusion.

In this study, mechanical properties of Al-Zn alloys were conducted, with various parameters including Zn contents, grain size, and tensile strain rate. Experimental samples were all manufactured with friction stir processing method. Samples of Al-Zn alloys with the grain size of 1.5£gm, 1£gm, or 0.5£gm and five Zn concentration were pulled in tension at strain rate of 10-3s-1,10-4s-1 and 10-5s-1 . The data set were then used to draw engineering and true tensile stress vs. strain curves , flowing stress vs. Zn contents curves, Hall-Petch equation curves, m vs. Zn contents curves and m vs. grain size curves. Quantitative analysis were conducted to discover that solid solute softening and inverse Hall-Petch relation were present in Al-Zn alloys, which were more prominent at slower tensile strain rate when grain size was less than 1£gm and the Zn contents was higher than 10wt%. Quantitative analysis of strain rate sensitivity (m) showed the trends of increasing value of m with higher Zn contents and smaller grain sizes when solid solute softening and inverse Hall-Petch relation were present. The high grain-boundary diffusion coefficient of Zn which accelerates the efficiency of dynamic recovery are considered the main reason. The effect gets more prominent with increasing Zn contents , smaller grain size , and slower tensile strain rate. For Zn concentration higher than 10wt%, dynamic recovery may drive inverse Hall-Petch relation to appear when grain size is about 1£gm large.

Lime softening, chlorination, clarification and filtration have been long recognized treatment processes for beverage water specifically the carbonated soft drink (CSD) because it provides consistent water quality required for bottling plants, however these processes are becoming uneconomical and causes more problems than the benefits they offer. These processes require very large foot print, occupy large plant volume, and generate large volume of sludge which causes disposal problems. Chlorination produces trihalomethanes (THMs) and other by-products which are detrimental to health and imparts tastes to the final products. Using the newly developed submerged spiral wound ultrafiltration membranes in conjunction with lime softening may replace the conventional lime softening, clarification and filtration processes. This research was conducted to demonstrate the feasibility of integrating immersed ultrafiltration (UF) membrane with lime softening. The objectives of this research was to achieve the water quality required by the CSD bottlers; determine the relationships of operating parameters such as pH and membrane flux with trans-membrane pressure (TMP), and membrane permeability; determine the optimum dosage of lime; evaluate the operating parameters as basis for the design and construction of the full scale plant; and predict the membrane cleaning intervals. A pilot unit consisting of lime reactor and UF system was designed and built for this research. The pilot unit was operated at various pH ranging from 7.3 to 11.2 and at membrane flux rates of 15, 30 and 45 gfd. The pilot unit was also operated at the CSD bottler’s operating conditions which is pH 9.8 at flux of 30 gfd. The pilot unit operated for a total of 1800 hours. The raw water source was from city water supply. The filtrate from the pilot unit achieved alkalinity reduction to 20 to 30 mg/L preferred by CSD bottlers, with lime dosage close to the calculated value. The filtrate turbidity during the test was consistently within 0.4 to 0.5 NTU. The TMP values obtained during the test ranges from 0.1 to 2.5 psi, while the permeability values ranges from 18.19 to 29.6 gfd/psi. The increase in flux results to corresponding increase in TMP, and increase in operating pH, increases the rate of TMP. Permeability decreases with increasing operating pH. The TOC reduction ranges from 2.6 % to 15.8% with increasing operating pH. No scaling of the UF membranes was observed during the test. Thirty days UF membrane cleaning interval was predicted. The results from this research can use as the basis of designing and operating a full scale Lime Softening UF Treatment Plant.

Roof falls and accumulation of dangerous gasses are the most common hazards in any underground coal mine. Different mechanisms can jeopardize the stability of the roof in underground excavations and successful roof control can only be obtained if the failure mechanism is identified and understood properly. The presence of discontinuities, the inherent variability of the rock mass and discontinuity properties, and the uncertainties associated with directions and magnitudes of the in-situ stress makes the rock engineering problems challenging. The numerical modeling can assist the ground control engineers in designing and evaluating the stability of the underground excavations. If extensive geological and geotechnical data are available, then detailed predictions of deformation, stress and stability can be accomplished by performing numerical modeling. If not, still the numerical modeling can be used to perform parametric studies to gain insight into the possible ranges of responses of a system due to likely ranges of various parameters. The parametric studies can help to identify the key parameters and their impact on stability of underground excavations. The priorities of the material testing and site investigation can be set based on the selected key parameters from parametric studies. An underground coal mine in western Pennsylvania is selected as a case study mine to investigate the underlying causes of roof falls at this mine. The immediate roof at the case study mine consists of laminated silty shale, shale, or sandstone that changes from area to area, and the floor is shale or soft fireclay. This study was mainly focused in the stability analysis of the roofs with the laminated silty shale rock type, where the majority of roof falls had taken place in the roof with this type of roof material. Extensive laboratory tests were performed on the core samples obtained from the case study mine to estimate the intact rock and discontinuity properties of the materials that occur in large extent at the selected interest area of the case study mine. In this research, the three-dimensional distinct element method was used to investigate the stability of the roof in an underground room-and-pillar coal mine. The implemented technique was able to accurately capture the failure of the major discontinuities and rock masses which consist of intact rock and minor discontinuities. In order to accurately replicate the post failure behavior of the rock layers in the immediate roof area, the strain-softening material constitutive law was applied to this region. Extensive numerical parametric studies were conducted to investigate the effect of different parameters such as the variation of immediate roof rock mass strength properties, variation of discontinuity mechanical properties, orientations and magnitudes of the horizontal in-situ stresses, and the size of pillars and excavations on stability of the excavations. The distribution of post failure cohesion along with other measures such as accumulated plastic shear strain, distribution of Z-displacements at the roofline, failure state (joint slip and tensile failure) and displacement (normal and shear displacements) of discontinuities were used to accurately assess the roof stability in this case study. The research conducted in this dissertation showed that the bedding planes play an important role on the behavior of roof in underground excavations. Therefore, an appropriate numerical modeling technique which incorporates the effect of discontinuities should be employed to simulate the realistic behavior of the discontinuous rock masses such as the layered materials in roof strata of the underground coal mines. The three-dimensional distinct element method used in this research showed the clear superiority of this technique over the continuum based methods.

The main purpose of this thesis is to improve the fundamental knowledge of non-isothermal tempering of martensite phase and its effects on the reduction in hardness (softening) with respect the base metal occurring at the heat affected zone (HAZ) of resistance spot welded dual-phase (DP) steels. This thesis also aims at understanding the influence of HAZ-softening on the joint performance of various DP steel grades. The tempering of martensite occurring at the sub-critical HAZ (SC-HAZ) of resistance spot welded DP600, DP780 and DP980 steels has been systematically evaluated by microhardness testing through Vickers indentation and the degree of tempering has been correlated to the HAZ-softening. From the joint performance analysis of similar and dissimilar steel grade combinations assessed through standardized testing methods, three important issues have been targeted: a) the joint strength (maximum load to failure), b) the location of failure (failure mode), and c) the physical characteristic of the weld that determines certain type of failure (weld nugget size). In addition, a partial tensile test has been conducted in order to evaluate the initiation of failure in dissimilar steel grade combinations. It has been shown that HAZ-softening lowered the weld size at which transition from interfacial to pullout failure mode takes place along with increased load-bearing capacity and higher energy absorption. Thus, it is concluded from mechanical testing that HAZ-softening benefits the lap-shear tensile joint performance of resistance spot welded DP steels by facilitating pullout failures through failure initiation at the SC-HAZ (tempered region). Instrumented nanoindentation testing was employed to further investigate HAZ-softening along the SC-HAZ by evaluating individual phases of ferrite matrix and tempered martensite islands. Although the ferrite matrix presented a slight reduction in hardness at nanoscale, higher reduction in hardness (softening) resulted for tempered martensite; thus confirming that tempered martensite is the major contributor to softening at micro-scale. A comparison between nanohardness and microhardness testing made at different distances from the line of lower critical temperature of transformation (Ac1) allowed revealing the actual extension of the SC-HAZ. In this regard, good correlation was obtained between nanohardness results along the SC-HAZ and the microstructural changes analyzed by electron microscopy (i.e., the tempering of martensite occurring at various distances far from Ac1 was correlated to low temperature tempering of dual phase steels). An in-depth analysis of the tempering of martensite phase at high temperature in DP steel subjected non-isothermal conditions i.e., rapid heating, extremely short time at peak temperature and rapid cooling (resistance spot welding), has been carried out mainly through analytical transmission electron microscopy (TEM). In addition, an isothermal tempering condition (i.e., slow heating and long time at peak temperature) in DP steel has been evaluated for complementing the analysis. Both non-isothermal and isothermal conditions have been correlated to the softening behaviour. TEM analysis of the base metal in the DP steel indicated that the morphology of the martensite phase is dependent on its carbon content, and its tempering characteristics are similar to that of equal carbon containing martensitic steel. The isothermally tempered structure is characterized by coarsening and spheroidization of cementite (θ) and complete recovery of the martensite laths; whereas precipitation of fine quasi-spherical intralath θ-carbides, coarser plate-like interlath θ-carbides, decomposition of retained austenite into elongated θ-carbides, and partial recovery of the lath structure were observed after non-isothermal tempering of DP steel. This difference in tempering behaviour is attributed to synergistic effect of delay in cementite precipitation due to higher heating rate, and insufficient time for diffusion of carbon that delays the third stage of tempering process (cementite coarsening and recrystalization) during non-isothermal. The finer size and the plate-like morphology of the precipitated carbides along with the partial recovery of the lath structure observed after non-isothermal tempering strongly influenced the softening behaviour of DP steel. The chemical analysis of θ-carbides through extraction replicas for three different DP steels revealed that the chemistry of the carbides is inherited from the parent DP steel during non-isothermal tempering at high temperature confirming that non-isothermal tempering DP steel is predominantly controlled by carbon diffusion.

Emotionally Focused Couple Therapy (EFT; Johnson, 2004) addresses relationship distress by facilitating the development of new patterns of interaction between partners. These new patterns of interaction are based on partners' vulnerable acknowledgement and expression of attachment needs. Partners' engagement in these new patterns of interaction is thought to improve their relationship-specific attachment bond. Although previous studies have shown EFT to result in excellent relationship satisfaction outcomes (Johnson, Hunsley, Greenberg & Schindler, 1999), research had yet clearly to demonstrate if and how EFT facilitates increases in partners' relationship-specific models attachment security over the course of therapy. To address this research gap, the current study employed Hierarchical Linear Modelling (HLM; Singer & Willet, 2003) to investigate the pattern of change in couples' (n=32) self-reported relationship satisfaction and relationship-specific attachment over the course of EFT. Couples reported significant linear increases in their relationship satisfaction and significant linear decreases in their relationship-specific attachment avoidance over the course of therapy. Couples who completed the blamer-softening therapeutic change event (n=16) demonstrated significant linear decreases in their relationship-specific attachment anxiety after completing this event. Decreases in relationship-specific attachment anxiety predicted increases in couples' relationship satisfaction over the course of therapy. Couples also demonstrated significant increases in the security of their pre-post-therapy relationship-specific attachment behaviour, as coded Secure Base Scoring System (Crowell, Treboux, Gao, Fyffe, Pan & Waters, 2002). The current study also used HLM (Singer & Willet, 2003) to examine how the completion of blamer-softening impacted softened couples' relationship-specific attachment anxiety, and whether the completion of blamer-softening had a similar impact on softened couples' relationship-specific attachment avoidance and relationship satisfaction. Softened couples reported an immediate increase in relationship satisfaction and immediate decrease relationship-specific attachment avoidance at the softening session. Further, softened couples' post-softening decreases in relationship-specific attachment anxiety were initially preceded by an increase at the softening session. These results provided an understanding of how EFT leads to increases in couples' relationship-specific attachment security. These results provide support for the use of attachment theory in the treatment of relationship distress, and also provide an illustration of how attachment can shift over the course of a therapeutic intervention.

Emotionally Focused Couple Therapy (EFT; Johnson, 2004) is an empirically validated approach to couple therapy that uses attachment theory to understand the needs and emotions of romantic partners. In EFT, relationship distress is conceptualized as resulting from negative affect, emotional disconnection, and unmet attachment needs. Although EFT is recognized as one of the most researched and effective approaches to couple therapy, little research has examined theoretically related characteristics of couples to changes in marital satisfaction throughout EFT. The present doctoral thesis examined this area of literature. Thirty-two couples were provided approximately 21 sessions of EFT. The goal of the first study was to identify intake characteristics related to change in marital satisfaction over the course of EFT. Couples completed self-report measures of marital satisfaction, attachment security, relationship trust, and emotional control at pre- and post-therapy and after each therapy session. Individuals higher on self-report attachment anxiety and higher levels of emotional control had greater change in marital satisfaction over the course of EFT. The goal of the second study was to examine intake levels of attachment security and its relationship to the occurrence of the blamer-softening event, a key change event in EFT, and changes in marital satisfaction. Results indicated that the occurrence of a blamer-softening event significantly predicted positive changes in marital satisfaction. Results also suggested that the occurrence of a softening event significantly moderated the relationship between attachment avoidance at intake and change in marital satisfaction from pre- to post-therapy. For couples who completed a blamer-softening event, partners with lower levels of attachment avoidance were more likely to have positive changes in marital satisfaction. However, this relationship was not evident for attachment anxiety. Overall, results from this thesis suggest that attachment security is a key characteristic of couple partners for therapists to consider when implementing EFT. Therapists may benefit from assessing attachment security at the start of therapy to help inform them of the emotion regulating strategies used by couple partners. This information may help therapists to tailor specific interventions such that couples may begin to develop more secure attachment bonds.

This thesis investigates the stability of coal pillars under realistic conditions of varying weak floor thickness with and without the use of paste backfill. Weak floor strata underlying coal seams are common in the Illinois Basin. They consist mainly of underclay, which is a gray, argillaceous rock that usually occurs immediately beneath beds of coal. Underclay thickness may vary from less than a foot to twenty feet at different locations in the basin (Grim and Allen, 1938). Locally, underclay thickness may vary gradationally over a distance of two pillars. Even though weak floor thickness is not consistent (Gadde, 2009), most research to date has focused on parametric studies with a fixed underclay thickness and formulated coal pillar designs on the basis of the maximum underclay thickness measured in the field. Therefore, it is necessary to investigate more realistic field conditions and quantify the influence of a gradated weak floor thickness using additional parametric studies. This research is primarily numerical modeling incorporating various constitutive models and using some calibration. Therefore, the two dimensional plane strain finite difference model in FLAC 3D is employed to carry out parametric studies on gradated weak floor conditions. Underclay exhibits Mohr Coulomb elastic plastic behavior; hence, the Mohr Coulomb constitutive model is used for the behavior of overburden, coal, and floor. Well-calibrated numerical models can assist in understanding load and failure processes provided that coal, overburden, and weak floor are modeled with sufficient realism. The theoretical approach considers a friction angle of 0° to calculate the load bearing capacity of the weak floor for design of pillars with long-term stability, even if the weak floor has a non-zero friction angle. The stiffness of the weak floor increases with an increase in friction angle (Gadde, 2009; Kostecki and Spearing, 2015). As stiffness increases, a point can be reached where floor bearing capacity exceeds coal pillar strength and coal pillar strength becomes the governing factor. For this scenario, the Mohr Coulomb strain softening model is more realistic in estimating loads carried by coal pillars in the post-failure stage. The three-dimensional Mohr Coulomb strain softening model in FLAC 3D is employed to study qualitatively the floor response in strain softening coal behavior conditions. Maintaining stable coal pillar responses has been a challenge for the coal mining industry due to attempts to increase the primary extraction ratio. Presently, the best available solution seems to be backfilling when considering short-term pillar stability (i.e., less than the long-term factor of safety) with increased extraction ratio. There are various types of mine backfill that have benefits to the mining industry depending on the application, but paste backfill produced from total mill tailings containing no free water is the best option for post-mining ground control in room-and-pillar mines as it prevents weakening of the floor and will not contaminate the ground water. The influence of paste backfill on floor bearing capacity and coal pillar response is studied with numerical modeling using the same constitutive models already identified. Finally, an economic analysis is carried out to look at cost implications of a proposed system with backfill.

Emotionally Focused Couple Therapy (EFT; Johnson, 2004) addresses relationship distress by facilitating the development of new patterns of interaction between partners. These new patterns of interaction are based on partners' vulnerable acknowledgement and expression of attachment needs. Partners' engagement in these new patterns of interaction is thought to improve their relationship-specific attachment bond. Although previous studies have shown EFT to result in excellent relationship satisfaction outcomes (Johnson, Hunsley, Greenberg & Schindler, 1999), research had yet clearly to demonstrate if and how EFT facilitates increases in partners' relationship-specific models attachment security over the course of therapy. To address this research gap, the current study employed Hierarchical Linear Modelling (HLM; Singer & Willet, 2003) to investigate the pattern of change in couples' (n=32) self-reported relationship satisfaction and relationship-specific attachment over the course of EFT. Couples reported significant linear increases in their relationship satisfaction and significant linear decreases in their relationship-specific attachment avoidance over the course of therapy. Couples who completed the blamer-softening therapeutic change event (n=16) demonstrated significant linear decreases in their relationship-specific attachment anxiety after completing this event. Decreases in relationship-specific attachment anxiety predicted increases in couples' relationship satisfaction over the course of therapy. Couples also demonstrated significant increases in the security of their pre-post-therapy relationship-specific attachment behaviour, as coded Secure Base Scoring System (Crowell, Treboux, Gao, Fyffe, Pan & Waters, 2002). The current study also used HLM (Singer & Willet, 2003) to examine how the completion of blamer-softening impacted softened couples' relationship-specific attachment anxiety, and whether the completion of blamer-softening had a similar impact on softened couples' relationship-specific attachment avoidance and relationship satisfaction. Softened couples reported an immediate increase in relationship satisfaction and immediate decrease relationship-specific attachment avoidance at the softening session. Further, softened couples' post-softening decreases in relationship-specific attachment anxiety were initially preceded by an increase at the softening session. These results provided an understanding of how EFT leads to increases in couples' relationship-specific attachment security. These results provide support for the use of attachment theory in the treatment of relationship distress, and also provide an illustration of how attachment can shift over the course of a therapeutic intervention.