Browsing by Subject "Safety"
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Item A Holistic Approach to Safety Assessment in the Life Cycle of Biodiesel Industry(2014-12-02) El-Said, Marwa HA number of goals have been set in several countries to rapidly increase biofuels production and focus more on sustainable energy resources because of limited fossil fuel reserves versus renewable biofuels, global warming and climate change. Biodiesel considers very attractive environmentally friendly fuel because it is compatible with the existing diesel engines with little or no modification needed. The majority of the studies performed to improve the biofuel industry was done from economic, environmental or social point of view but failed to include the safety aspects in the whole analysis. In this thesis, a holistic approach is presented to conduct a life-cycle assessment of the risks associated with the supply, transportation, processing, storage, and production of biomass to biodiesel by assessing technologies and supply chains. Total risk calculations were done quantitatively and semi-quantitatively utilizing the historical record of the reported accidents/incidents from 2006 to 2013 in the United States. Based on the work done in this thesis, several key results were obtained. It was found that fire in biodiesel plants accounts for the most likely scenario for an accident (around 85% of total accidents). It was also found that the process area contributed the highest percentage of accidents (43%) followed by storage (33%). In the transportation phase, the overwhelming majority of events (98%) occurred as a result of spillage. In general, the thesis results demonstrate that assessing the risk utilizing the real accident scenarios to know the safety trend involved can be utilized afterwards to anticipate the upcoming loss from the capacity increase. The results also provide further evidence on the effectiveness of the use of overall risk calculations to get better understanding of the incident situations, facilitate more organized and successful emergency response, highlight the areas that need more attention and improvement, and more importantly act towards a life-cycle approach that is aimed at keeping overall risk within acceptable limits. The thesis analyzes reported data and discusses root causes and potential mitigation strategies.Item Criteria based evaluation of stopping trajectories in serial manipulators(2009-12) Steinfeld, Bryan Christopher; Tesar, Delbert; Pryor, MitchIn the past few years, there has been a large push towards adapting traditional industrial manipulators to other, more consumer-centric applications [1]. These include not only house and elderly care, but also towards medical applications that manipulators may be especially suited for, such as rehabilitation of patients who have suffered neurological trauma [2]. Impeding this push are the strict safety requirements necessary to certify a manipulator for use. These requirements include low speed operation and preventing humans from entering the manipulator workspace [3]. These restrictions effectively prevent a manipulator from being used in many of these applications. Previous work done in manipulator safety research has focused on improving the system’s knowledge of its environment and controlling the manipulator’s motion to keep away from potential hazards. These methods are extremely important in terms of avoiding potential collisions but provide little insight into the situation that occurs once a hazard occurs and the manipulator is forced to react. In order to improve upon the ability to evaluate a manipulator’s overall safety, this report establishes a framework to evaluate the capacity of a manipulator to safely “halt” itself. Two sets of criteria are presented in this report. The first set seeks to quantify both the potential of the manipulator to avoid a collision during the stopping motion and the potential severity of the collision. The second set of criteria quantifies the effect of the stopping motion at the actuator level, allowing the operator to identify potential hardware faults and the capacity to which the actuators are performing. A framework for mapping the manipulator’s actuator parameters for the gear reduction ratio and the motor torque to the potential safety criteria performance is formulated to allow the manipulator designer to match task requirements to the manipulator design. Finally, an examination of the effects on operating parameters such as manipulator configuration, end-effector load, and operating speed is presented with a 6DOF industrial manipulator. This analysis showed that the operating speed of the manipulator is the most important determinant of the safety performance, with the distance traveled by the manipulator increasing by a factor of 15 for all configurations when the speed is increased only by a factor of four. Recommendations for the application of these criteria are presented to the reader as well.Item Determining the extent and characteristics of overrepresentation of large truck crashes in daytime and nighttime work zones(2009-05-15) Mokkapati, NaveenThe growth of vehicle travel in the United States has accelerated wear on the interstate highway system leading to frequent pavement repair and rehabilitation projects. The presence of work zones not only causes traffic congestion and backup but also increases the crash risk. Therefore, the FHWA (Federal Highway Administration) has allotted a significant amount of funds to improve work zone traffic safety and operations. This thesis compares truck and automobile crash characteristics in work zones with those of non-work zones and thus identifies engineering countermeasures to improve work zone truck safety. The researcher used a contingency analysis approach in this study. First, he categorized the North Carolina crash data using different variables. Once categorized, the Breslow-Day test is used to compare the odds of truck and automobile crashes between work zones and non-work zones. Overall, the researcher did not find a significant difference between odds of truck and automobile crashes compared to previous studies. The researcher believes that the difference in results between the present study and the previous studies could either be due to differences in the approach used or better truck management techniques employed by the North Carolina DOT (Department of Transportation). The researcher also identified that the maintenance projects performed during the day had a significantly higher odds of truck crashes relative to that of automobiles in work zones compared to control sections when workers were present, either with a lane closure or without a lane closure. The researcher believes that the results from the day maintenance projects and its subcategories are the key findings of this study. Therefore, these key findings are used to identify the possible reasons and countermeasures for any disproportionate change in truck to automobile crashes. The identified list of countermeasures includes the use of law enforcement, a smart work zone system, a dynamic late merge system, CMS (Changeable Message Signs), speed display signs, and a CB (Citizen Band) Wizard. These countermeasures were checked for cost effectiveness using a benefit cost (B/C) analysis. The researcher found that law enforcement, smart work zones with costs lower than or equal to half a million dollars, CMS, speed display signs, and the CB Wizard have B/C ratios greater than one and seem to be worthwhile for deployment in work zones. Smart work zones with significantly higher costs of 2.5 million dollars, for example, could be deployed using a more detailed analysis of work zone characteristics. Finally, dynamic late merge system could be used if the site conditions indicate a crash reduction potential of at least 10 ? 15 percent.Item Effectiveness of using video modeling for teaching safety skills for children with autism and other developmental disabilities(2011-05) Sokolosky, Stephanie A.; Banda, Devender R.; Lechtenberger, DeAnn; Carter, Stacy L.Children with disabilities including autism spectrum disorders and other developmental disabilities often need training in safety-related areas. Literature indicates that video modeling has been effective in teaching play activities, as well as social and communication skills. In addition, there are few studies where young children with developmental disabilities, including autism, have been taught safety skills. Video modeling has been shown to be effective in teaching safety skills, however to date it has not been used in teaching these skills to young children with developmental disabilities. The purpose of this study was to evaluate the effectiveness of using video modeling to train young children with autism spectrum disorders or developmental disabilities to walk around a 3-dimensional yellow safety marker used in many public locations. The marker indicated a wet area below the marker. Five students, between ages 5 and 6 years, watched a 2-minute video of an adult demonstrating the proper procedure for safely walking around the safety marker. After watching the video the student was prompted to walk down the hall, then reinforced for completing the task using a simple social reinforcement. An A-B design across subjects, with a generalization phase, was used to evaluate the effectiveness of the intervention. The results indicated that the use of video modeling was effective in training young children with developmental disabilities and autism spectrum disorders to learn this safety skill. In addition, the five participants successfully generalized the new safety skill to a novel setting. Results are discussed and implications for research and practice are provided.Item Essays on mechanism design, safety, and crime(2014-05) Shoukry, George Fouad Nabih; Abrevaya, Jason; Stinchcombe, MaxwellThis dissertation uses theoretical and empirical tools to answer applied questions of design with an emphasis on issues relating to safety and crime. The first essay incorporates safety in implementation theory and studies when and how safe mechanisms can be designed to obtain socially desirable outcomes. I provide general conditions under which a social choice rule can be implemented using safe mechanisms. The second essay is an empirical study of how criminals respond to changing profitability of crime, a question that informs the policy debate on the most effective crime fighting methods. I find that the price elasticity of theft is about 1 in the short term and increases to about 1.2 over a seven-month horizon, suggesting that policies that directly affect crime profitability, such as policies that shut down black markets or those that reduce demand for illegal goods, can be relatively effective. The third essay shows that any standard implementation problem can be formulated as a question about the existence of a graph that solves a graph coloring problem, establishing a connection between implementation theory and graph theory. More generally, an implementation problem can be viewed as a constraint satisfaction problem, and I propose an algorithm to design simple mechanisms to solve arbitrary implementation problems.Item Evaluation of Alternatives for Safer and More Efficient Reactions: A study of the N-oxidation of Alkylpyridines(2012-02-14) Saenz Noval, Lina RocioThe catalytic N-oxidation of alkylpyridines, a reaction which uses hydrogen peroxide as the oxidizing agent and the water soluble phosphotungstic acid as the catalyst, is a reaction employed in the pharmaceutical industry. The safety concerns of this process revolve around the decomposition of hydrogen peroxide and the liquid-liquid phase separation of the reacting mixture. The decomposition of hydrogen peroxide is an undesired reaction parallel to the desired N-oxidation and is responsible for: 1) a high potential for runaway due to the condition sensitivity of the peroxide group, 2) a potential over-pressurization of the reaction vessel during a runaway due to the production of oxygen, and 3) the enrichment with oxygen of the flammable alkylpyridine environment. The presence of an organic phase and an aqueous phase occurs in a wide range of conditions and results in: 1) a dramatic reduction in the reaction selectivity, and consequently in the efficiency, due to the additional mass transfer constrains imposed by the phase separation, and 2) the safety of the process being seriously compromised because most of the catalyst remains in the aqueous phase, excessively promoting the decomposition of hydrogen peroxide over the N-oxidation. With these concerns in mind, this research aimed to determine conditions for an inherently safer and more efficient N-oxidation reaction and focused on three key targets: i) the possibility of reducing the extend of the decomposition of hydrogen peroxide, thus leading to an inherently safer process, ii) the study of phase equilibrium so as to enable the identification of conditions that increase the efficiency of the N-oxidation and reduces the hazards, and iii) the evaluation of safety parameters that will allow for the control of a potential runaway reaction. Two alkylpyridines were considered: 2-methylpyridine which represents the case of a homogeneous reacting mixture and 2,6-dimethylpyridine to study the two-liquid phase separation effects. The methodology employed calorimetric studies to assess the runaway behavior and to determine the conditions that favor the N-oxidation, and for the N-oxidation of 2,6-dimethylpyridine, thermodynamic studies were incorporated to evaluate the conditions for phase separation.Item Evaluation of the impact of cardiovascular safety concerns of thiazolidinediones on the utilization of oral antidiabetic drugs(2011-05) Bui, Cat Nguyen; Rascati, Karen L.; Wilson, James P.; Godley, Paul J.; Prasla, KarimThe overall objective of this study was to evaluate the impact of cardiovascular safety concerns on the utilization of the thiazolidinediones (TZDs), pioglitazone and rosiglitazone, and other oral antidiabetic drugs. In May 2007, a meta-analysis was published that found a potential increased risk of myocardial infarction (MI) associated with TZDs, particularly with rosiglitazone. A two-year retrospective study of patients diagnosed with type 2 diabetes (ICD9 250.xx) using prescription and medical databases from the Scott & White Health System (SWHS) was conducted. Patients aged 18 or older who were continuously enrolled with SWHS from 2006 to 2008 and had high adherence (Medication Adherence Ratio ≥80%) for either pioglitazone or rosiglitazone during the pre-safety warning period (May 2006- April 2007) were included. Patients were followed through the post-safety warning period (May 2007 - October 2008) or occurrence of event (discontinuation of index TZD drug). Patients who discontinued their index TZD drug by April 2008 were identified if they had a prescription filled for a new oral antidiabetic drugs (OADs), and followed until October 2008 or occurrence of event (discontinuation of new OAD). Cox proportional hazards models were used to assess the rate of and time to discontinuation of index TZD and new OAD with adjustment of age, gender and Charlson Comorbidity Index (CCI). A total of 531 patients (58 percent male; mean age [SD] = 61 [9.1] years) were included in the final analysis, 255 and 276 patients in the rosiglitazone and pioglitazone groups, respectively. The rate of discontinuation for the pioglitazone and rosiglitazone groups began to separate within 90 days of the index event (meta-analysis published in May 2007). In the pioglitazone group, the rate of discontinuation was significantly lower than in the rosiglitazone group ( HR = 0.56; 95% CI = 0.47, 0.67). A total of 21 patients did not experience discontinuation of their index medication. Among patients receiving a new OAD after discontinuing their index TZD (N = 95 rosiglitazone and N = 33 pioglitazone patients), there was no statistical significant in the rate of discontinuing their new OAD between the rosiglitazone and pioglitazone groups (HR = 0.98; 95% CI = 0.61, 1.59). However, patients who received metformin/sulfonylurea combinations had a lower rate of discontinuation compared to patients who received sulfonylureas (HR = 0.38; 94% CI = 0.21, 0.66). The analysis showed the cardiovascular safety concern of TZDs had a significant impact on the utilization of oral antidiabetic drug utilization.Item Framework for Understanding the Relationship between Lean and Safety in Construction(2011-08-08) Prakash, RamyaLean construction borrows concepts from lean manufacturing and Toyota Production System in order to eliminate waste and add value to the construction process. Manufacturing processes utilizing lean principles have matured and developed a clear understanding of the relation between lean and safety. Because lean in construction is a relatively new phenomenon, there is not a completely developed understanding of how lean practices affect safety in construction. The Lean Construction Institute and the Academic Forum for Lean Construction has recently targeted this area for focused research. Since all safety incidents imply waste in time and resources, lean and safety have a common ground in the minimization of waste. This thesis researches the common ground of lean and safety in waste minimization and proposes a framework for understanding their relationship. This thesis also critically analyzes lean and safety principles to form an insight to the relationship between lean theories as well as practices and safety issues reported in construction literature. Further, literature also revealed the safety strategies and checklists that companies typically incorporate in their program. A comparative analysis of lean and safety is employed to understand their relations in a better way. This framework establishes that lean and safety have a strong relationship in the context of construction. Future work is needed to show that lean practices indeed strongly affect safety by reducing the number of incidents.Item HOT Lane Policies and Their Implications(2011-08-08) Goel, RahulHigh-Occupancy toll (HOT) lanes allow lower-occupant vehicles (LOVs) to use a HOV lane for a fee, while maintaining free travel to qualifying HOVs. HOT lanes are gaining interest throughout the country as a strategy for meeting multiple performance objectives in congested urban freeway corridors. Currently there are ten fully operational HOT lanes around the country in seven different states and this research examined the nine of them (excluding I-35 W). Even with only a handful of operational HOT lane projects, there is great diversity in terms of HOT lane design and operations. With HOT lane implementation there are many issues, including: toll rates, vehicle occupancy requirement, number of access points, and safety. This research examined (i) the different factors which lead to the development of the HOT lanes in their respective corridors (ii) the objectives of the HOT lanes (iii) changes made in the corridor due to HOT lane implementation (iv) the different impacts of the HOT lanes and (v) the extent to which the objectives of the HOT lanes were achieved. Using three pairs of HOT lanes with similar design and operational characteristics, comparisons were made to examine the impacts of the similar HOT lanes in two different corridors. With the strict registration requirement for HOV3+ on the I-95 Express Lanes there were indications that some carpoolers broke up in to lower occupancy vehicles. Tolled access for HOV2s on I-95 as well as the SR 91 Express Lanes resulted in lower usage of the Express Lanes by the HOV2s (fewer than 30 percent of the total corridor HOV2s) as compared to a conventional HOV lane (60 percent) where HOV2 access is free. The effect of availability of transit on the HOT lanes can also be seen from SR 91 as compared to I-95. On SR 91, the Express bus does not use the Express Lanes and there was almost no change in its ridership after the Express Lanes were implemented. However, on I-95, the Express bus uses the Express Lanes and travel time of buses decreased by 17 minutes due to Express Lanes implementation. The Express bus ridership also increased by 30 percent. On the SR167 and I-25 HOT lanes, the exogenous factors like gas prices and economic recession seemed to influence the usage of the HOT lanes. In both the HOT Lanes, carpool usage was positively correlated to the gasoline prices. On I-25, the increasing unemployment rate coincided with the decreasing toll paying travelers. On SR 167 there were also indications of mode shifts among the transit, carpool and toll paying SOVs due to fluctuating gas prices. With declining gas prices, the transit and carpool usage went down while toll paying users increased. An inverse relationship between the convenience of access points and the safety perceived by the HOT lane users was found. For example, I-15 Express Lanes in Salt Lake City reduced the access points from unrestricted with the previous HOV lanes to limited with the Express Lanes. As a result, more predictable merging led to an increase in the perceived safety of the Express lanes as well as the speed of the corridor. On the other hand, some carpoolers mentioned not using the Express Lanes anymore because of access inconvenience. The access inconvenience was also mentioned by previous carpoolers in HOV lanes on I-95 as one of the reasons for not using the Express Lanes. These findings underscore the importance of outreach programs during the planning process of the HOT lanes to minimize the confusion among the previous users of the HOV lanes and spreading awareness among them regarding the increased safety benefits.Item "I Never Thought It Would Happen Here": White Privilege and Assumptions of Safety(2014-05-03) Varela, Kay SCriminology and media scholars over the last two decades convincingly argue that crime is one of the major social problems of this era. Racialized constructions of safety and space, however, continue to be the dominant paradigm through which crime is viewed and the hypervigilance of people of color legitimized. I argue that depictions of white communities as pure, homogenous, and calm spaces permit and facilitate whites? tendency to link danger and violence to people of color, which not only reinforces existing stereotypes that associate people of color with the dangerous side of the safety continuum, but also harks back to a history when white space was violently protected and its isolation legally sanctioned. Using 155 newspaper articles taken from four Chicago area newspapers from January 2008 to January 2013 (The Chicago Tribune, The Chicago Defender, La Raza Chicago, and The Daily Herald), I conduct a structurally contextualized critical discourse analysis and engage several different categories of frames, particularly in three areas: 1) neighborhood contextualization; 2) safety concern of the article; and 3) how the incident being reported on is described and understood in terms of locality. My analysis highlights the white supremacist logic found and upheld in newspaper discourse; a discourse that focuses on white normative standards of safety while also structuring the way in which people and communities of color experience safety. As such, my analysis indicates demonstrates discourse surrounding safety and crime indicate an often unnoticed privilege?the privilege of being able to presume safety?that is denied to people and communities of color and almost guaranteed to whites and white communities.Item Improved regulatory oversight using real-time data monitoring technologies in the wake of Macondo(2014-08) Carter, Kyle Michael; Van Oort, EricAs shown by the Macondo blowout, a deepwater well control event can result in loss of life, harm to the environment, and significant damage to company and industry reputation. Consistent adherence to safety regulations is a recurring issue in deepwater well construction. The two federal entities responsible for offshore U.S. safety regulation are the Department of the Interior’s Bureau of Safety and Environmental Enforcement (BSEE) and the U.S. Coast Guard (USCG), with regulatory authorities that span well planning, drilling, completions, emergency evacuation, environmental response, etc. With such a wide range of rules these agencies are responsible for, safety compliance cannot be comprehensively verified with the current infrequency of on-site inspections. Offshore regulation and operational safety could be greatly improved through continuous remote real-time data monitoring. Many government agencies have adopted monitoring regimes dependent on real-time data for improved oversight (e.g. NASA Mission Control, USGS Earthquake Early Warning System, USCG Vessel Traffic Services, etc.). Appropriately, real-time data monitoring was either re-developed or introduced in the wake of catastrophic events within those sectors (e.g. Challenger, tsunamis, Exxon Valdez, etc.). Over recent decades, oil and gas operators have developed Real-Time Operations Centers (RTOCs) for continuous, pro-active operations oversight and remote interaction with on-site personnel. Commonly seen as collaborative hubs, RTOCs provide a central conduit for shared knowledge, experience, and improved decision-making, thus optimizing performance, reducing operational risk, and improving safety. In particular, RTOCs have been useful in identifying and mitigating potential well construction incidents that could have resulted in significant non-productive time and trouble cost. In this thesis, a comprehensive set of recommendations is made to BSEE and USCG to expand and improve their regulatory oversight activities through remote real-time data monitoring and application of emerging real-time technologies that aid in data acquisition and performance optimization for improved safety. Data sets and tools necessary for regulators to effectively monitor and regulate deepwater operations (Gulf of Mexico, Arctic, etc.) on a continuous basis are identified. Data from actual GOM field cases are used to support the recommendations. In addition, the case is made for the regulator to build a collaborative foundation with deepwater operators, academia and other stakeholders, through the employment of state-of-the-art knowledge management tools and techniques. This will allow the regulator to do “more with less”, in order to address the fast pace of activity expansion and technology adoption in deepwater well construction, while maximizing corporate knowledge and retention. Knowledge management provides a connection that can foster a truly collaborative relationship between regulators, industry, and non-governmental organizations with a common goal of safety assurance and without confusing lines of authority or responsibility. This solves several key issues for regulators with respect to having access to experience and technical know-how, by leveraging industry experts who would not normally have been inaccessible. On implementation of the proposed real-time and knowledge management technologies and workflows, a phased approach is advocated to be carried out under the auspices of the Center for Offshore Safety (COS) and/or the Offshore Energy Safety Institute (OESI). Academia can play an important role, particularly in early phases of the program, as a neutral playing ground where tools, techniques and workflows can be tried and tested before wider adoption takes place.Item Methodology for creating human-centered robots : design and system integration of a compliant mobile base(2012-05) Wong, Pius Duc-min; Sentis, Luis; Deshpande, AshishRobots have growing potential to enter the daily lives of people at home, at work, and in cities, for a variety of service, care, and entertainment tasks. However, several challenges currently prevent widespread production and use of such human-centered robots. The goal of this thesis was first to help overcome one of these broad challenges: the lack of basic safety in human-robot physical interactions. Whole-body compliant control algorithms had been previously simulated that could allow safer movement of complex robots, such as humanoids, but no such robots had yet been documented to actually implement these algorithms. Therefore a wheeled humanoid robot "Dreamer" was developed to implement the algorithms and explore additional concepts in human-safe robotics. The lower mobile base part of Dreamer, dubbed "Trikey," is the focus of this work. Trikey was iteratively developed, undergoing cycles of concept generation, design, modeling, fabrication, integration, testing, and refinement. Test results showed that Trikey and Dreamer safely performed movements under whole-body compliant control, which is a novel achievement. Dreamer will be a platform for future research and education in new human-friendly traits and behaviors. Finally, this thesis attempts to address a second broad challenge to advancing the field: the lack of standard design methodology for human-centered robots. Based on the experience of building Trikey and Dreamer, a set of consistent design guidelines and metrics for the field are suggested. They account for the complex nature of such systems, which must address safety, performance, user-friendliness, and the capability for intelligent behavior.Item Model for multi-strata safety performance measurements in the process industry(Texas A&M University, 2004-09-30) Keren, NirMeasuring process safety performance is a challenge, and the wide variations in understanding, compliance, and implementation of process safety programs increase the challenge. Process safety can be measured in three strata: (1) measurement of process safety elements within facilities; (2) benchmarking of process safety elements among facilities; and (3) use of incident data collection from various sources for industrial safety performance assessment. The methods presently available for measurement of process safety within facilities are deficient because the results are strongly dependent on user judgment. Performance benchmarking among facilities is done within closed groups of organizations. Neither the questionnaires nor the results are available to the public. Many organizations collect data on industrial incidents. These organizations differ from each other in their interests, data collection procedures, definitions, and scope, and each of them analyzes its data to achieve its objectives. However, there have been no attempts to explore the potential of integrating data sources and harnessing these databases for industrial safety performance assessment. In this study we developed models to pursue the measurement of samples of the strata described above. The measurement methodologies employed herein overcome the disadvantages of existing methodologies and increase their capabilities.Item Perceptions of Safety and Violence among Relationship Education Participants: A Grounded Theory Study(2011-08) Porter, Rob; Whiting, Jason B.; Smith, Douglas B.; Ivey, David C.; Harris, Steven M.Marriage and relationship education (MRE) has become a focus of national attention. With the passage of federal legislation appropriating money to promote MRE among low-income and minority populations, various states have begun to offer MRE workshops. However, as low-income populations are at increased risk for intimate partner violence (IPV), some are concerned that government endorsement of MRE will encourage participants (particularly women) to stay in or enter into unsafe and violent relationships. Research examining the relationship between MRE participation and IPV is in its infancy. Using both qualitative and quantitative methods and data collected from a federally-funded MRE program, this study examined the effect of participating in an MRE on an individual’s relationship as it relates to perceptions of safety and violence. A theory and model were developed which include 5 categories: group process, context, awareness, creating a safe environment, and relationship unity. Qualitative results indicate that participants move through a process from context to relationship unity, via the group process, awareness, and creating a safe environment. Quantitative results show an increase in perceptions of safety for the total SAFE scale and all three subscales (verbal/psychological, control, and physical) for the full sample. Similar results were found when analyses were completed by gender. Females, however, reported no significant difference between pre- and post-test for the physical subscale. A discussion of the findings and the implications thereof, as well as possible directions for future research, is provided.Item Quantitative relationships between crash risks and pavement skid resistance(2013-12) Long, Kan; Zhang, Zhanmin, 1962-Faced with continuously increasing maintenance due to aging infrastructure, the Texas Department of Transportation (TxDOT) is evaluating the potential impact of reduced funding on highway safety. The main objective of this thesis is to develop a methodological procedure to identify threshold levels of pavement skid resistance for highways in the context of traffic crashes, assisting TxDOT Administration and engineers in making proper maintenance decisions. As a result, the efficiency and safety of the highway system could be preserved. The scope of this study covers all types of state-maintained highways in Texas. The primary objectives of this thesis include: 1) synthesis of literature; 2) quantification of the relationship between crash risk and pavement skid resistant; 3) determination of critical skid resistant threshold levels; and, 4) benefit cost analysis. A detailed methodology framework was developed and a comprehensive database was generated from four data files containing pavement, geometry, traffic, and crash information to support this research. The impact of skid resistance level on crash risks was proven to be significant based on the results of regression analysis and insights provided by TxDOT experts. The quantitative relationships between crash risk and skid resistance were quantified using the Crash Rate Ratio method. Hierarchical structure grouping was used to categorize the entire network into homogeneous groups based on traffic level, roadway alignment and other factors. Critical skid resistance threshold levels were determined for the whole state as well as for stratified highway groups. Finally, benefit/cost ratio analyses were conducted to evaluate the effectiveness of pavement maintenance treatments to restore or increase skid resistance.Item Safety first? : looking at a non-traditional safety training program for Spanish-speaking construction workers(2012-12) Prochnow, Allison Nicole; Zamora, Emilio; Zamora, Emilio; Stidvent, VeronicaConstruction is a very deadly industry with Texas having the highest rate of deaths of construction workers of any state. Hispanic workers are at an even higher risk than white, non-Hispanic workers for being injured or killed while working on a construction site. However, traditional materials available through the Occupational Safety and Health Administration (OSHA) to train workers in job safety cannot effectively reach the Hispanic construction worker population because of language and educational barriers. This study examines a non-traditional safety training program tailored specifically for Spanish monolingual construction workers in order to reach these otherwise hard-to-reach workers, created by Workers Defense Project (WDP) in Austin, Texas, through a Department of Labor grant. Through participatory learning techniques, WDP has had a high rate of success in educating low-literacy, Spanish monolingual construction workers on workplace safety and rights. Through further evaluation of this program, the unique methods utilized in this training can be developed and applied in other areas and industries to reduce the number of injuries and fatalities in construction and other hazardous industries.Item Safety, effectiveness, and cost among Texas Medicaid patients with Diabetic Macular Edema (DME) or Age-Related Macular Degeneration (AMD)(2014-12) Jiang, Shan, 1986-; Barner, Jamie C.Although bevacizumab is one of the most commonly used treatments for DME and AMD, there are concerns regarding safety and effectiveness due to its off-label use. The study objectives were to determine if: 1) the risk of cardiovascular/ hemorrhagic events (safety) and visual impairment (effectiveness) differed by bevacizumab use (i.e., use vs. non-use and number of treatments) among DME and AMD patients; and 2) direct medical costs differed between DME and DME control patients. A retrospective cohort analysis was conducted with Texas Medicaid medical and prescription data (9/1/07-12/31/12) for patients: 18- 63 years, continuously enrolled 1-year pre- and post-index, and diagnosed with DME or AMD. The index date was the first date of diagnosis. The dependent variables were: 1) cardiovascular/hemorrhagic risk; 2) visual impairment; 3) direct medical costs. The independent variables were bevacizumab use and number of bevacizumab treatments. Covariates were disease state, Charlson Comorbidity Index (CCI) score, total medication use, number of laser treatments, and demographics. Propensity scoring technique was used to match: 1) bevacizumab users and non-users; and 2) DME and DME control cohorts. Descriptive analyses, logistic regression, Cox-regression, and generalized linear models were employed. A final cohort of 3,647 DME, 297 AMD, and 57,897 DME control patients were included. The majority (DME and AMD) was between 45-63 years of age (86.6%), Hispanic (54.0%), and female (65.1%). The mean total number of unique medications and mean CCI were 2.7 ± 3.4 and 6.0 ± 3.3, respectively. Total direct medical costs/person (Mean (±SD)) incurred by DME, DME control, and AMD subjects in the post-index period were $6,704(±9,338), $5,495(±10,153), and $4,935(±12,702), respectively. No differences in cardiovascular/ hemorrhagic risk were found between bevacizumab users and non-users. The claims data lacks the detail to determine the effectiveness of bevacizumab. DME control patients had lower overall direct medical costs than DME patients (p<0.0001). In conclusion, although bevacizumab is a less expensive off-label alternative of ranibizumab, the choice between bevacizumab and ranibizumab should be made through careful consideration. However, as the use of anti-VEGF agent increases, further research should be conducted to determine if any changes in cardiovascular adverse events occur.Item Spironolactone to treat hypertension in end-stage renal disease : analysis of effectiveness and safety(2013-05) Smith, Amber Lanae; Koeller, JimPurpose: Cardiovascular events and complications are the major causes of death in patients with end-stage renal disease (ESRD)¹⁻³. Antihypertensive agents that block the renin-angiotensin-aldosterone system (RAAS) are considered first-line therapy in patients with ESRD as these patients have a propensity for RAAS overactivation⁴⁻⁷. Studies show that aldosterone receptor blockade reduces BP in patients with chronic kidney disease (CKD) and helps prevent negative outcomes from continued renal cellular damage⁸⁻¹⁰. Spironolactone, an aldosterone antagonist, has the potential to provoke hyperkalemia. Consequently, current guidelines do not recommend spironolactone to manage hypertension in ESRD because of this risk⁶⁻⁷. Our primary objectives were to determine the change in BP and serum potassium levels following spironolactone use. Methods: This study was a retrospective, pre-post cohort study in ESRD patients with difficult-to-control BP receiving HD. Patients prescribed spironolactone (25 mg to 50 mg) between January 2009 and January 2013 were identified using an e-prescribing record from three HD clinics in San Antonio, TX. Patients were included if they were prescribed spironolactone as 'add-on' therapy to control BP for at least 8 weeks. Results: Seventy patients were evaluated and the majority of them were overweight, diabetic, Hispanic females with a mean 65 years of age. Mean SBP and DBP decreased from baseline to week 8 [-20.74 mmHg (p < 0.0001) and -9.7 mmHg (p < 0.0426), respectively]. Mean serum potassium levels increased by an average of 0.18 mEq/L (4.5 mEq/L to 4.68 mEq/L, p = 0.09). Data analysis revealed that only 9 of 70 patients had a serum potassium level > 5.5 mEq/L at week 8. There were no adverse cardiac events reported as a result of these potassium concentrations. A two-fold decrease in SBP was seen in patients with a body mass index (BMI) > 25 kg/m² compared to patients with a BMI of ≤ 25 kg/m². At the end of the study, 23 patients (33%) achieved the goal BP for healthy adults of < 140/90 mmHg. Conclusion: These findings demonstrated that using spironolactone use in ESRD patients receiving HD can be effective and safe.Item The true impact of late deliverables at the construction site(2014-05) Barry, William Ryan; Leite, Fernanda; O'Brien, William J.Given that a construction site is both temporary and unique, the outcome of every construction project is dependent upon having all of the proper resources delivered to the site at the appropriate time. Although this is common knowledge in the construction industry, late deliverables to the site continue to be a major impediment to project success. In order to better understand late deliverables and their impacts on performance, the Construction Industry Institute, in collaboration with the Construction Users Roundtable, commissioned Research Team (RT) 300 to investigate how various types of late deliverables affect the cost, schedule, quality, safety, and organizational performance of industrial construction projects. Using case studies, industry surveys and questionnaires, existing literature, and internal team expertise, RT 300 developed two research thrusts: investigate how the industry understands, manages, and is affected by late deliverables, and document and give visibility to the true risks and impacts associated with late deliverables. When examining how late deliverables affect the construction industry, RT 300 found that (1) there is limited understanding of the full range of late deliverables and their far-reaching impacts, (2) the most common late deliverables tend to have the most severe impacts on projects, (3) project teams are typically reactionary when managing late deliverables, (4) project stakeholders have varying perceptions of the risks and impacts associated with late deliverables, and (5) proactively managing late deliverables and impacts is key for improvement in the industry. With these findings and the second research thrust in mind, RT 300 created a database tool, the Late Deliverable Risk Catalog (LDRC), to document common types of late deliverables, give visibility to the full range of impacts, and help project teams recognize risks, improve alignment, and proactively manage late deliverables and mitigate the impacts. RT 300 has also developed implementation recommendations for the LDRC, prevention recommendations for the highest risk deliverables, and lessons learned in managing late deliverables. Altogether, this research can help improve the understanding of late deliverables and resulting impacts and risks in order to improve project delivery, productivity, and predictability as well as enhance safety, quality, and organizational and individual performance.Item Visual Attention and Driver Performance at Horizontal Curves(2014-12-02) Brimley, Bradford K.Despite the frequency with which drivers encounter curves on highways, curves are regularly identified as locations that experience disproportionately high crash rates. Crash data suggest that inattention is one of the leading causes of crashes at any location and on any facility. Traffic control devices (TCDs) can be installed at curves to provide drivers the information necessary for safe navigation. The research in this dissertation examines the theory that TCDs at curves are not only beneficial because they provide drivers information, but also because TCDs promote increased attention. With increased attention, drivers then navigate the curve more safely. A study of driver behavior was conducted to examine three hypotheses regarding the relationships between driver attention, navigational performance, and TCDs that are used at curves: 1) TCDs lead to improvements in operational performance at curves, 2) TCDs lead to increased attention in advance of curves, and 3) increased attention before curves leads to improved performance within the curve. The driver-behavior study included the collection of eye-tracking and operations (speed and acceleration) data from unfamiliar drivers on a two-lane highway. Data were collected from over 100 study participants who each drove for approximately 1 hour. The hypotheses were tested using multivariable mixed models that identify relationships between the three components (TCDs, attention, and performance) while accounting for geometric and operational features at each curve. The principal findings from the study are that: 1) drivers operationally respond to TCDs by adopting a more-conservative behavior, 2) TCDs affect attention by influencing when drivers perceive relevant curve information, and 3) an earlier increase in cognition leads to a more-conservative navigation. Since TCDs influence where drivers perceive a curve, and the perception influences the operational performance, it is suggested that the selection of TCDs at curves can be based on the distance required for drivers to make a natural maneuver in advance of the curve in preparation for navigating it.