Seismic performance of hybrid fiber reinforced polymer-concrete pier frame systems

As an alternative to transverse spiral or hoop steel reinforcement, fiber reinforced polymers (FRPs) were introduced to the construction industry in the 1980’s. The concept of concrete-filled FRP tube (CFFT) has raised great interest amongst researchers in the last decade. FRP tube can act as a pour form, protective jacket, and shear and flexural reinforcement for concrete. However, seismic performance of CFFT bridge substructure has not yet been fully investigated. Experimental work in this study included four two-column bent tests, several component tests and coupon tests. Four 1/6-scale bridge pier frames, consisting of a control reinforced concrete frame (RCF), glass FRP-concrete frame (GFF), carbon FRP-concrete frame (CFF), and hybrid glass/carbon FRP-concrete frame (HFF) were tested under reverse cyclic lateral loading with constant axial loads. Specimen GFF did not show any sign of cracking at a drift ratio as high as 15% with considerable loading capacity, whereas Specimen CFF showed that lowest ductility with similar load capacity as in Specimen GFF. FRP-concrete columns and pier cap beams were then cut from the pier frame specimens, and were tested again in three point flexure under monotonic loading with no axial load. The tests indicated that bonding between FRP and concrete and yielding of steel both affect the flexural strength and ductility of the components. The coupon tests were carried out to establish the tensile strength and elastic modulus of each FRP tube and the FRP mold for the pier cap beam in the two principle directions of loading. A nonlinear analytical model was developed to predict the load-deflection responses of the pier frames. The model was validated against test results. Subsequently, a parametric study was conducted with variables such as frame height to span ratio, steel reinforcement ratio, FRP tube thickness, axial force, and compressive strength of concrete. A typical bridge was also simulated under three different ground acceleration records and damping ratios. Based on the analytical damage index, the RCF bridge was most severely damaged, whereas the GFF bridge only suffered minor repairable damages. Damping ratio was shown to have a pronounced effect on FRP-concrete bridges, just the same as in conventional bridges. This research was part of a multi-university project, which is founded by the National Science Foundation (NSF) - Network for Earthquake Engineering Simulation Research (NEESR) program.

The Lack of a Structured Universal Healthcare System in the United States: How This Affects the Lives of Millions of Americans and What Can Be Done About It

The purpose of this research is to explore on a deeper level the healthcare system of the United States, its background, and other factors that could provide possible solutions to simplify the fragmented healthcare system. The ultimate goal is the formation of concise ideas that could make the system, which prevents millions of Americans from obtaining adequate medical attention, substantially better. The paper will offer a better insight into the four different models of healthcare insurance found around the world in other developed countries with the purpose of establishing a comparison with that of the United States. The changes implemented by the Patient Protection and Affordable Care Act of 2010 are also analyzed to arrive at the conclusion of whether it has helped more American citizens get access to medical attention. Quality Improvement tools and thorough analysis of different methods from a financial, managerial, legal, and administrative perspective are used to provide valuable information that could aid in the implementation of modifications to the healthcare system of the United States in the near future.

Seismic Performance of Hybrid Fiber Reinforced Polymer-Concrete Pier Frame Systems

As an alternative to transverse spiral or hoop steel reinforcement, fiber reinforced polymers (FRPs) were introduced to the construction industry in the 1980's. The concept of concrete-filled FRP tube (CFFT) has raised great interest amongst researchers in the last decade. FRP tube can act as a pour form, protective jacket, and shear and flexural reinforcement for concrete. However, seismic performance of CFFT bridge substructure has not yet been fully investigated. Experimental work in this study included four two-column bent tests, several component tests and coupon tests. Four 1/6-scale bridge pier frames, consisting of a control reinforced concrete frame (RCF), glass FRP-concrete frame (GFF), carbon FRP-concrete frame (CFF), and hybrid glass/carbon FRP-concrete frame (HFF) were tested under reverse cyclic lateral loading with constant axial loads. Specimen GFF did not show any sign of cracking at a drift ratio as high as 15% with considerable loading capacity, whereas Specimen CFF showed that lowest ductility with similar load capacity as in Specimen GFF. FRP-concrete columns and pier cap beams were then cut from the pier frame specimens, and were tested again in three point flexure under monotonic loading with no axial load. The tests indicated that bonding between FRP and concrete and yielding of steel both affect the flexural strength and ductility of the components. The coupon tests were carried out to establish the tensile strength and elastic modulus of each FRP tube and the FRP mold for the pier cap beam in the two principle directions of loading. A nonlinear analytical model was developed to predict the load-deflection responses of the pier frames. The model was validated against test results. Subsequently, a parametric study was conducted with variables such as frame height to span ratio, steel reinforcement ratio, FRP tube thickness, axial force, and compressive strength of concrete. A typical bridge was also simulated under three different ground acceleration records and damping ratios. Based on the analytical damage index, the RCF bridge was most severely damaged, whereas the GFF bridge only suffered minor repairable damages. Damping ratio was shown to have a pronounced effect on FRP-concrete bridges, just the same as in conventional bridges. This research was part of a multi-university project, which is founded by the National Science Foundation (NSF) Network for Earthquake Engineering Simulation Research (NEESR) program.

The Performance and Service Life Prediction of High Performance Concrete in Sulfate and Acidic Environments

Concrete substructures are often subjected to environmental deterioration, such as sulfate and acid attack, which leads to severe damage and causes structure degradation or even failure. In order to improve the durability of concrete, the High Performance Concrete (HPC) has become widely used by partially replacing cement with pozzolanic materials. However, HPC degradation mechanisms in sulfate and acidic environments are not completely understood. It is therefore important to evaluate the performance of the HPC in such conditions and predict concrete service life by establishing degradation models. This study began with a review of available environmental data in the State of Florida. A total of seven bridges have been inspected. Concrete cores were taken from these bridge piles and were subjected for microstructural analysis using Scanning Electron Microscope (SEM). Ettringite is found to be the products of sulfate attack in sulfate and acidic condition. In order to quantitatively analyze concrete deterioration level, an image processing program is designed using Matlab to obtain quantitative data. Crack percentage (Acrack/Asurface) is used to evaluate concrete deterioration. Thereafter, correlation analysis was performed to find the correlation between five related variables and concrete deterioration. Environmental sulfate concentration and bridge age were found to be positively correlated, while environmental pH level was found to be negatively correlated. Besides environmental conditions, concrete property factor was also included in the equation. It was derived from laboratory testing data. Experimental tests were carried out implementing accelerated expansion test under controlled environment. Specimens of eight different mix designs were prepared. The effect of pozzolanic replacement rate was taken into consideration in the empirical equation. And the empirical equation was validated with existing bridges. Results show that the proposed equations compared well with field test results with a maximum deviation of ± 20%. Two examples showing how to use the proposed equations are provided to guide the practical implementation. In conclusion, the proposed approach of relating microcracks to deterioration is a better method than existing diffusion and sorption models since sulfate attack cause cracking in concrete. Imaging technique provided in this study can also be used to quantitatively analyze concrete samples.

The effects of sex of teacher, sex of scenario principal, and leadership style on the performance ratings of scenario principals by teachers

This study was designed to address questions regarding the effects of sex and leadership style on teacher perceptions of principal effectiveness. On a researcher-designed instrument, middle school teachers rated the effectiveness of a scenario principal's response in several situations. The responses reflected varying levels of Task and Relationship Behavior.^ The design incorporated two between subjects factors (Teacher Sex and Principal Sex) and one within subjects factor (Leadership Style) which was treated as a repeated measure. An analysis of variance revealed no significant effects except for Leadership Style. Overall, High Task/High Relationship behavior rated significantly higher and Low Task/Low Relationship rated significantly lower than the others. The null hypothesis concerning differences could not be rejected and the stated research hypotheses were not supported.^ Additional analyses of variance were conducted substituting subject demographic variables for Teacher Sex in the research design. No significant interactions or main effects other than Leadership Style were noted when either Age or Ethnicity were substituted.^ A significant two-way interaction was noted for Teacher Experience and Leadership Style (p =.0316). Less experienced teachers rated principal's performance lower when exhibiting High Task/Low Relationship style than did more experienced teachers. A significant three-way interaction was noted for Administrative Aspiration x Principal Sex x Leadership Style (p =.0294). Teachers who indicated an intent to enter administration differed more on their ratings between male and female principals exhibiting mixed styles of High Task/Low Relationship and Low Task/High Relationship than did teachers who indicated no or undecided.^ Sex of the teacher appears less important than sex of the principal on performance ratings. Results suggest further study of the effects of teacher experience and teacher administrative aspiration on perceptions of principal effectiveness. ^

Development of surface flaw thresholds for pre-cured fiber reinforced polymer and groove size tolerance for near surface mounted fiber reinforced polymer retrofit systems

Since the introduction of fiber reinforced polymers (FRP) for the repair and retrofit of concrete structures in the 1980’s, considerable research has been devoted to the feasibility of their application and predictive modeling of their performance. However, the effects of flaws present in the constitutive components and the practices in substrate preparation and treatment have not yet been thoroughly studied. This research aims at investigating the effect of surface preparation and treatment for the pre-cured FRP systems and the groove size tolerance for near surface mounted (NSM) FRP systems; and to set thresholds for guaranteed system performance. This study was conducted as part of the National Cooperative Highway Research Program (NCHRP) Project 10-59B to develop construction specifications and process control manual for repair and retrofit of concrete structures using bonded FRP systems. The research included both analytical and experimental components. The experimental program for the pre-cured FRP systems consisted of a total of twenty-four (24) reinforced concrete (RC) T-beams with various surface preparation parameters and surface flaws, including roughness, flatness, voids and cracks (cuts). For the NSM FRP systems, a total of twelve (12) additional RC T-beams were tested with different grooves sizes for FRP bars and strips. The analytical program included developing an elaborate nonlinear finite element model using the general purpose software ANSYS. The bond interface between FRP and concrete was modeled by a series of nonlinear springs. The model was validated against test data from the present study as well as those available from the literature. The model was subsequently used to extend the experimental range of parameters for surface flatness in pre-cured FRP systems and for groove size study in the NSM FRP systems. Test results, confirmed by further analyses, indicated that contrary to the general belief in the industry, the impact of surface roughness on the global performance of pre-cured FRP systems was negligible. The study also verified that threshold limits set for wet lay-up FRP systems can be extended to pre-cured systems. The study showed that larger surface voids and cracks (cuts) can adversely impact both the strength and ductility of pre-cured FRP systems. On the other hand, frequency (or spacing) of surface cracks (cuts) may only affect system ductility rather than its strength. Finally, within the range studied, groove size tolerance of ±1/8 in. does not appear to have an adverse effect on the performance of NSM FRP systems.

The relationship between a retention program and the persistence and graduation rates of first-generation low-income students at an urban, public university

The purpose of this study was to examine the relationship between participation in a retention program designed to promote academic and social integration and the persistence rates of first generation, low-income college students at an urban, public multiethnic university. Archival data were collected from the university’s Office of Institutional Research and the retention program office and included SAT/ACT scores, GPA, gender, ethnicity, and program participation data. A total of 292 first-generation, low-income students who were admitted to the university in the summer of 1999 were identified for the study. A group of 166 students were selected for the comparison group because they had not participated in the retention program; 126 students had participated in the retention program. ^ Three major research questions guided this study: (a) Are there differences in persistence rates and other academic characteristics of underprepared, low-income, first generation college students who participate and do not participate in the retention program?; (b) Does involvement in the retention program predict student persistence of first generation low-income, underprepared students?, and (c) Can predictors of GPA be identified for students in the retention program using program and descriptive variables? ^ A series of logistic regression analyses were conducted to assess the relationship between various retention services and the persistence and graduation rates of participants. The results showed that there were statistically significant relationships between participation and non-participation in the retention program and having higher GPAs and higher graduation and persistence rates. Of the four program features, participation in tutoring, workshops, and social events were found to be predictors of graduation. College GPA was also found to be a predictor of graduation for all students. The results also showed that women were more likely to graduate than men.^

Menu Analysis: Review and Evaluation

In the article - Menu Analysis: Review and Evaluation - by Lendal H. Kotschevar, Distinguished Professor School of Hospitality Management, Florida International University, Kotschevar’s initial statement reads: “Various methods are used to evaluate menus. Some have quite different approaches and give different information. Even those using quite similar methods vary in the information they give. The author attempts to describe the most frequently used methods and to indicate their value. A correlation calculation is made to see how well certain of these methods agree in the information they give.” There is more than one way to look at the word menu. The culinary selections decided upon by the head chef or owner of a restaurant, which ultimately define the type of restaurant is one way. The physical outline of the food, which a patron actually holds in his or her hand, is another. These descriptions are most common to the word, menu. The author primarily concentrates on the latter description, and uses the act of counting the number of items sold on a menu to measure the popularity of any particular item. This, along with a formula, allows Kotschevar to arrive at a specific value per item. Menu analysis would appear a difficult subject to broach. How does a person approach a menu analysis, how do you qualify and quantify a menu; it seems such a subjective exercise. The author offers methods and outlines on approaching menu analysis from empirical perspectives. “Menus are often examined visually through the evaluation of various factors. It is a subjective method but has the advantage of allowing scrutiny of a wide range of factors which other methods do not,” says Distinguished Professor, Kotschevar. “The method is also highly flexible. Factors can be given a score value and scores summed to give a total for a menu. This allows comparison between menus. If the one making the evaluations knows menu values, it is a good method of judgment,” he further offers. The author wants you to know that assigning values is fundamental to a pragmatic menu analysis; it is how the reviewer keeps score, so to speak. Value merit provides reliable criteria from which to gauge a particular menu item. In the final analysis, menu evaluation provides the mechanism for either keeping or rejecting selected items on a menu. Kotschevar provides at least three different matrix evaluation methods; they are defined as the Miller method, the Smith and Kasavana method, and the Pavesic method. He offers illustrated examples of each via a table format. These are helpful tools since trying to explain the theories behind the tables would be difficult at best. Kotschevar also references examples of analysis methods which aren’t matrix based. The Hayes and Huffman - Goal Value Analysis - is one such method. The author sees no one method better than another, and suggests that combining two or more of the methods to be a benefit.

The effects of sex of teacher, sex of scenario principal and leadership style on the performance ratings of scenario principals by teachers

This study was designed to address questions regarding the effects of sex and leadership style on teacher perceptions of principal effectiveness. On a researcher-designed instrument, middle school teachers rated the effectiveness of a scenario principal's response in several situations. The responses reflected varying levels of Task and Relationship Behavior. The design incorporated two between subjects factors (Teacher Sex and Principal Sex) and one within subjects factor (Leadership Style) which was treated as a repeated measure. An analysis of variance revealed no significant effects except for Leadership Style. Overall, High Task/High Relationship behavior rated significantly higher and Low Task/Low Relationship rated significantly lower than the others. The null hypothesis concerning differences could not be rejected and the stated research hypotheses were not supported. Additional analyses of variance were conducted substituting subject demographic variables for Teacher Sex in the research design. No significant interactions or main effects other than Leadership Style were noted when either Age or Ethnicity were substituted. A significant two-way interaction was noted for Teacher Experience and Leadership Style (p = .0316). Less experienced teachers rated principal's performance lower when exhibiting High Task/Low Relationship style than did more experienced teachers. A significant three-way interaction was noted for Administrative Aspiration x Principal Sex x Leadership Style (p = .0294). Teachers who indicated an intent to enter administration differed more on their ratings between male and female principals exhibiting mixed styles of High Task/Low Relationship and Low Task/High Relationship than did teachers who indicated no or undecided. Sex of the teacher appears less important than sex of the principal on performance ratings. Results suggest further study of the effects of teacher experience and teacher administrative aspiration on perceptions of principal effectiveness.

Once a Catholic : a novel in stories and poems

"Once A Catholic" is a novel about the indelible effects of growing up Catholic. The novel is told in a series of stories and poems. The first story, "Credo," offers an overview of the rich culture of Catholicism that binds the Daley family together. "Before The Fall" recalls the safety and warmth of that Catholic faith. Subsequent stories focus on individual family members and events, and the Catholicity that lies at their core. "Holy Orders" tells the story the firstborn male child whose destination is the priesthood. "Finding Ecstasy" is a daughter's story of rebellion through sexual exploration. "Sweet Reconciliation" is the story of a search within oneself for forgiveness, the cornerstone of Catholic upbringing. "Acts of the Apostle" demonstrates the hopelessness of a faith under attack. The final story, "Holy Relics," demonstrates the never-ending desire for redemption and the important act of returning sacredness to its rightful place.