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Title
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The Application of Chemometrics to the Detection and Classification of Ignitable Liquids in Fire Debris Using the Total Ion Spectrum.
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Creator
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Lewis, Jennifer, Sigman, Michael, Campiglia, Andres, Clausen, Christian, University of Central Florida
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Abstract / Description
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Current methods in ignitable liquid identification and classification from fire debris rely on pattern recognition of ignitable liquids in total ion chromatograms, extracted ion profiles, and target compound comparisons, as described in American Standards for Testing and Materials E1618-10. The total ion spectra method takes advantage of the reproducibility among sample spectra from the same American Society for Testing and Materials class. It is a method that is independent of the...
Show moreCurrent methods in ignitable liquid identification and classification from fire debris rely on pattern recognition of ignitable liquids in total ion chromatograms, extracted ion profiles, and target compound comparisons, as described in American Standards for Testing and Materials E1618-10. The total ion spectra method takes advantage of the reproducibility among sample spectra from the same American Society for Testing and Materials class. It is a method that is independent of the chromatographic conditions that affect retention times of target compounds, thus aiding in the use of computer-based library searching techniques. The total ion spectrum was obtained by summing the ion intensities across all retention times. The total ion spectrum from multiple fire debris samples were combined for target factor analysis. Principal components analysis allowed the dimensions of the data matrix to be reduced prior to target factor analysis, and the number of principal components retained was based on the determination of rank by median absolute deviation. The latent variables were rotated to find new vectors (resultant vectors) that were the best possible match to spectra in a reference library of over 450 ignitable liquid spectra (test factors). The Pearson correlation between target factors and resultant vectors were used to rank the ignitable liquids in the library. Ignitable liquids with the highest correlation represented possible contributions to the sample. Posterior probabilities for the ASTM ignitable liquid classes were calculated based on the probability distribution function of the correlation values. The ASTM ignitable liquid class present in the sample set was identified based on the class with the highest posterior probability value. Tests included computer simulations of artificially generated total ion spectra from a combination of ignitable liquid and substrate spectra, as well as large scale burns in 20'x8'x8' containers complete with furnishings and flooring. Computer simulations were performed for each ASTM ignitable liquid class across a range of parameters. Of the total number of total ion spectra in a data set, the percentage of samples containing an ignitable liquid was varied, as well as the percent of ignitable liquid contribution in a given total ion spectrum. Target factor analysis was them performed on the computer-generated sample set. The correlation values from target factor analysis were used to calculate posterior probabilities for each ASTM ignitable liquid class. Large scale burns were designed to test the detection capabilities of the chemometric approach to ignitable liquid detection under conditions similar to those of a structure fire. Burn conditions were controlled by adjusting the type and volume of ignitable liquid used, the fuel load, ventilation, and the elapsed time of the burn. Samples collected from the large scale burns were analyzed using passive headspace adsorption with activated charcoal strips and carbon disulfide desorption of volatiles for analysis using gas chromatography-mass spectrometry.
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Date Issued
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2011
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Identifier
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CFE0004477, ucf:49301
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004477
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Title
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THE UNITED NATIONS FUND FOR POPULATION ACTIVITIES: CHANGING THE DIRECTION OF THE TOTAL FERTILITY RATE IN DEVELOPING NATIONS.
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Creator
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Fazecas, Michaela, ME Jungblut, Bernadette, University of Central Florida
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Abstract / Description
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This thesis builds on previous United Nations' research investigating factors affecting the Total Fertility Rate (TFR) in six (6) states: Burkina Faso, Mexico, Morocco, Nepal, the Philippines, and Uganda. The present research, however, provides a broader assessment of the TFR and the potential causes of its decline by examining countries across nine (9) regions of the world sub-Saharan Africa, Latin America, South Asia, East Asia, the Middle East and North Africa, the Caribbean, the...
Show moreThis thesis builds on previous United Nations' research investigating factors affecting the Total Fertility Rate (TFR) in six (6) states: Burkina Faso, Mexico, Morocco, Nepal, the Philippines, and Uganda. The present research, however, provides a broader assessment of the TFR and the potential causes of its decline by examining countries across nine (9) regions of the world sub-Saharan Africa, Latin America, South Asia, East Asia, the Middle East and North Africa, the Caribbean, the Pacific Islands, Eastern and Southeastern Europe, and the former Soviet Socialist Republics of the Commonwealth of Independent States. The present analyses are also conducted over time, specifically from 1960 through 2002.Five (5) primary hypotheses regarding factors affecting the Total Fertility Rate are examined using feasible generalized least squares regression analysis. First, foreign debt is hypothesized to have a positive relationship to TFR. That is, holding all else constant, as foreign debt increases, TFR is expected to increase as well. Foreign debt is operationalized first, as total external debt; second, as long-term debt, and third, as total debt service as a percentage of exports of goods and services. Second, foreign aid, the level of socioeconomic development, and the extent of females' education are all hypothesized to have negative relationships to TFR. That is, all else constant, as foreign aid increases, TFR is expected to decrease. All else constant, as the level of socioeconomic development increases, TFR is also expected to decrease. All else constant, as the extent of females' education increases, TFR is also expected to decrease. Foreign aid is operationalized as first, International Bank for Reconstruction and Development (IBRD) loans and International Development Agency (IDA) credits; and second, as official development assistance and official aid. The level of socioeconomic development is operationalized as the Gross National Income (GNI) per capita in terms of purchasing power parity. The extent of females' education is operationalized as first, the adult female literacy rate (ages 15 and above), and second, as the ratio of young literate females to males (ages 15 24). Finally, whereas previous scholars have hypothesized that industrialization reduces TFR (the Western European "demographic transition" hypothesis), the present research proposes that this relationship may not hold in developing countries. This possibility is investigated by analyzing the relationships between TFR and first, the value added of agriculture (as a percentage of GDP); second, the value added of industry (also as a percentage of GDP); third, the value added of manufacturing as a percentage of GDP; and fourth, the value added of services as a percentage of GDP. The findings presented here suggest first, that the foreign debt and foreign aid have differing effects on TFR in different regions of the world. Second, the effects of socioeconomic development and females' education are more consistent (than foreign debt and foreign aid) across the different regions but intriguing variations still exist. Finally, it appears that, with very few exceptions, the Western European-based demographic transition model does not hold for non-Western and developing areas. Therefore, new, region-specific models of TFR need to be developed and public policy needs to be based on these more accurate, more context-appropriate models.
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Date Issued
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2004
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Identifier
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CFE0000139, ucf:46169
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0000139
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Title
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STEPHEN SONDHEIM'S GESAMTKUNSTWERK: THE CONCEPT MUSICAL AS WAGNERIAN TOTAL THEATRE.
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Creator
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Calderazzo, Diana, Listengarten, Julia, University of Central Florida
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Abstract / Description
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Stephen Sondheim, famous for writing such musicals as Company, Into the Woods, Sweeney Todd, and Assassins, is often referred to as the originator of the modern concept musical. Despite varying definitions of the concept musical, it is generally agreed that the form embodies a specific identity or mood, which it communicates to an audience both emotionally and intellectually. As such it offers audience members a complete experience resembling in theory the idea of "total theatre" proposed in...
Show moreStephen Sondheim, famous for writing such musicals as Company, Into the Woods, Sweeney Todd, and Assassins, is often referred to as the originator of the modern concept musical. Despite varying definitions of the concept musical, it is generally agreed that the form embodies a specific identity or mood, which it communicates to an audience both emotionally and intellectually. As such it offers audience members a complete experience resembling in theory the idea of "total theatre" proposed in the nineteenth century by composer Richard Wagner. My thesis will argue that the similarity between Sondheim's concept musical and Wagner's total theatre is more than purely theoretical; it is practical as well, involving structural parallels such as leitmotif, minor chord development, and intricate lyricism. Congruently, many of Sondheim's choices describing communication with audiences on the emotional and intellectual levels also recall those utilized by Wagner over a century earlier. These similarities not withstanding, Sondheim, as a contemporary artist, creates work that has often been described in terms of theoretical movements that post-date Wagner, including "desconstructionism" and Brechtian theatre. While these terms certainly describe some differences between the work of Sondheim and Wagner, I will argue that their existence with regard to Sondheim does not preclude a Wagnerian approach to the contemporary composer's work. Elements of deconstruction and Brechtian alienation may, in fact, be linked back to Wagner in specific manners. My thesis will explore these connections, concluding that an approach to the work of Sondheim in the vein of Richard Wagner may suggest a successful method of interpreting the contemporary concept musical.
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Date Issued
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2005
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Identifier
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CFE0000714, ucf:46598
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0000714
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Title
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LOW REYNOLDS NUMBER WATER FLOW CHARACTERISTICS THROUGH RECTANGULAR MICRO DIFFUSERS/NOZZLES WITH A PRIMARY FOCUS ON MAJOR/MINOR PRESSURE LOSS, STATIC PRESSURE RECOVERY, AND FLOW SEPARATION.
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Creator
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Hallenbeck, Kyle, Chew, Larry, University of Central Florida
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Abstract / Description
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The field of microfluidics has recently been gathering a lot of attention due to the enormous demand for devices that work in the micro scale. The problem facing many researchers and designers is the uncertainty in using macro scaled theory, as it seems in some situations they are incorrect. The general idea of this work was to decide whether or not the flow through micro diffusers and nozzles follow the same trends seen in macro scale theory. Four testing wafers were fabricated using PDMS...
Show moreThe field of microfluidics has recently been gathering a lot of attention due to the enormous demand for devices that work in the micro scale. The problem facing many researchers and designers is the uncertainty in using macro scaled theory, as it seems in some situations they are incorrect. The general idea of this work was to decide whether or not the flow through micro diffusers and nozzles follow the same trends seen in macro scale theory. Four testing wafers were fabricated using PDMS soft lithography including 38 diffuser/nozzle channels a piece. Each nozzle and diffuser consisted of a throat dimension of 100μm x 50μm, leg lengths of 142μm, and half angles varying from 0o 90o in increments of 5o. The flow speeds tested included throat Reynolds numbers of 8.9 89 in increments of 8.9 using distilled water as the fluid. The static pressure difference was measured from the entrance to the exit of both the diffusers and the nozzles and the collected data was plotted against a fully attached macro theory as well as Idelchik's approximations. Data for diffusers and nozzles up to HA = 50o hints at the idea that the flow is neither separating nor creating a vena contracta. In this region, static pressure recovery within diffuser flow is observed as less than macro theory would predict and the losses that occur within a nozzle are also less than macro theory would predict. Approaching a 50o HA and beyond shows evidence of unstable separation and vena contracta formation. In general, it appears that there is a micro scaled phenomenon happening in which flow gains available energy when the flow area is increased and looses available energy when the flow area decreases. These new micro scaled phenomenon observations seem to lead to a larger and smaller magnitude of pressure loss respectively.
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Date Issued
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2008
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Identifier
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CFE0002391, ucf:47772
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0002391
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Title
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An assessment of ecological processes in the Apalachicola estuarine system, Florida.
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Creator
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Smar, Daina, Hagen, Scott, Wang, Dingbao, Weishampel, John, University of Central Florida
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Abstract / Description
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The following is a compilation of field data collected in 2011 and 2012 in Apalachicola, FL as part of a five year study assessing the ecological effects of sea level rise in the northern Gulf of Mexico. Many coastal communities, both natural and developed, will soon be working to mitigate the effects of sea level rise, if they are not already doing so. This thesis investigates the natural patterns of the Apalachicola estuarine system through the collection and analysis of in situ water,...
Show moreThe following is a compilation of field data collected in 2011 and 2012 in Apalachicola, FL as part of a five year study assessing the ecological effects of sea level rise in the northern Gulf of Mexico. Many coastal communities, both natural and developed, will soon be working to mitigate the effects of sea level rise, if they are not already doing so. This thesis investigates the natural patterns of the Apalachicola estuarine system through the collection and analysis of in situ water, sediment, and biomass samples. Additionally, results of the field samples are presented and recommendations for additional sampling are given. The field methods and procedures developed in this study were designed to be repeated in other estuaries to build upon the work that has been conducted in Apalachicola. Water samples were tested for total suspended solids (TSS) and compared against hydrodynamic (tidal circulation and streamflow) and meteorological (wind and precipitation) characteristics. Streamflow was determined to influence a seasonal base level concentration of TSS. Wind strength and direction consistently influenced small TSS concentration fluctuations, an effect amplified by the shallow nature of the estuary. Tidal circulation appeared to have minor influences on TSS concentration fluctuations within the base level concentration range. Precipitation appeared to influence large TSS concentration fluctuations; however, due to limited data collection during storm events, more data is required to conclusively state this. Sediment cores throughout the lower Apalachicola River revealed that coarse particles settled out in upstream areas while fine particles tended to stay in suspension until low energy areas in the lower portions of the river or marsh system were reached. Finally, biomass samples were used to develop regression models utilizing remotely sensed data to predict biomass density in marsh areas with unprecedented accuracy. The documented patterns of this system are to be used as inputs and validation points to update an existing hydrodynamic model and to aid in the coupling and development of sediment transport and marsh equilibrium models. The field campaign developed and implemented here provides a foundation for this novel coupled modeling effort of estuarine systems. From the 2011 and 2012 sampling conducted, it is apparent that Apalachicola can be modeled as a closed system with river inflow and sediment influx as boundary conditions. Forcing local conditions should accurately represent the system. Ultimately, these models will be used to simulate future sea level rise scenarios and will provide useful decision making tools to coastal managers. Future work will include replicating water sampling in subsequent wet and dry seasons in Apalachicola, FL to confirm observed trends, in addition to implementing this sampling in Grand Bay, MS and Weeks Bay, AL. Additional biomass samples will be taken to validate the strong correlations found between remotely sensed data and in situ samples. In similar studies, it is recommended that water samples be taken to adequately represent influences from tidal cycles and riverine inflow. It is also recommended that spatially distributed biomass samples be taken to validate regression models.
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Date Issued
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2012
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Identifier
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CFE0004602, ucf:49920
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004602
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Title
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Comparison of a modified and traditional rapid infiltration basin for treatment and control of nutrients in wastewater effluent.
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Creator
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Cormier, Jessica, Duranceau, Steven, Wang, Dingbao, Sadmani, A H M Anwar, University of Central Florida
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Abstract / Description
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Rapid infiltration basins (RIB) have been historically used in Florida for groundwater recharge, effluent disposal, or a combination of both. However, this technique has proven ineffective in providing nitrogen control unless the RIB is modified in some manner. In this study, a traditional RIB was compared to a modified RIB constructed with manufactured biosorption activated media (BAM) to evaluate nitrate removal from reclaimed water. The RIBs are used for reclaimed and excess storm water...
Show moreRapid infiltration basins (RIB) have been historically used in Florida for groundwater recharge, effluent disposal, or a combination of both. However, this technique has proven ineffective in providing nitrogen control unless the RIB is modified in some manner. In this study, a traditional RIB was compared to a modified RIB constructed with manufactured biosorption activated media (BAM) to evaluate nitrate removal from reclaimed water. The RIBs are used for reclaimed and excess storm water disposal. Few, if any, studies have been published where BAM-modified RIBs have been used for this purpose. In this work, a mixture of clay, tire crumb, and sand (CTS) was selected to serve as the BAM material (Bold and Gold(TM) CTS media). Each RIB was constructed with two feet of either sand or BAM, covering more than 43,600 square feet of surface area. The BAM-modified RIB had an initial 90 pounds per cubic-foot in-place density, and the density of the control RIB approximated about 94 pounds per cubic-foot. Over an eight-month period, loadings to the BAM RIB and control RIB approximated 5.4 million gallons (MG) per acre each. Water samples, collected from lysimeters installed below the 2-foot of sand or BAM materials, were gathered monthly during 2017 (except for September and October due to the impacts of hurricane Irma); these samples were analyzed for water quality to determine nitrate removal. Soil moisture and weather data were also collected over the study period. This study demonstrated the nitrate removal effectiveness of a field-scale BAM-modified RIB as compared to a traditional field-scale sand-based RIB. Results suggest that BAM removed 30 percent more nitrates than the Control (78% and 47%, respectively) under the conditions of the study. Furthermore, BAM removed higher percentages of TN (31%) and TP (62%) than the Control (12% and 28%, respectively).
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Date Issued
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2018
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Identifier
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CFE0007566, ucf:52583
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0007566
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Title
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A NEW APPROACH TO IDENTIFY THE EXPECTED CRASH PATTERNS BASED ON SIGNALIZED INTERSECTION SIZE AND ANALYSIS OF VEHICLE MOVEMENTS.
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Creator
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Salkapuram, Hari, Mohamed, Abdel-Aty, University of Central Florida
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Abstract / Description
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Analysis of intersection crashes is a significant area in traffic safety research. This study contributes to the area by identifying traffic-geometric characteristics and driver demographics that affect different types of crashes at signalized intersections. A simple methodology to estimate crash frequency at intersections based on the size of the intersection is also developed herein. First phase of this thesis used the crash frequency data from 1,335 signalized intersections obtained from...
Show moreAnalysis of intersection crashes is a significant area in traffic safety research. This study contributes to the area by identifying traffic-geometric characteristics and driver demographics that affect different types of crashes at signalized intersections. A simple methodology to estimate crash frequency at intersections based on the size of the intersection is also developed herein. First phase of this thesis used the crash frequency data from 1,335 signalized intersections obtained from six jurisdictions in Florida, namely, Brevard, Seminole, Dade, Orange, and Hillsborough Counties and the City of Orlando. Using these data a simple methodology has been developed to identify the expected number of crashes by type and severity at signalized intersections. Intersection size, based on the total number of lanes, was used as a factor that was simple to identify and a representative of many geometric and traffic characteristics of an intersection. The results from the analysis showed that crash frequency generally increased with the increased size of intersections but the rates of increase differed for different intersection types (i.e., Four-legged intersection with both streets two-way, Four-legged intersection with at least one street one-way, and T-intersections). The results also showed that the dominant type of crashes differed at these intersection types and severity of crashes was higher at the intersections with more conflict points and larger differential in speed limits between major and minor roads. The analysis may potentially be useful for traffic engineers for evaluating safety at signalized intersections in a simple and efficient manner. The findings in this analysis provide strong evidence that the patterns of crashes by type and severity vary with the size and type of intersections. Thus, in future analysis of crashes at intersections, the size and type of intersections should be considered to account for the effects of intersection characteristics on crash frequency. In the second phase, data (crash and intersection characteristics) obtained from individual jurisdictions are linked to the Department of Highway Safety and Motor Vehicles (DHSMV) database to include characteristics of the at-fault drivers involved in crashes. These crashes are analyzed using contingency tables and binary logistic regression models. This study categorizes crashes into three major types based on relative initial movement direction of the involved vehicles. These crash types are, 1) Initial movement in same direction (IMSD) crashes. This crash type includes rear end and sideswipe crashes because the involved vehicles for these crashes would be traveling in the same direction prior to the crash. 2) Initial movement in opposite direction (IMOD) crashes comprising left-turn and head on crashes. 3) Initial movement in perpendicular direction (IMPD) crashes, which include angle and right-turn crashes. Vehicles involved in these crashes would be traveling on different roadways that constitute the intersection. Using the crash, intersection, and at-fault driver characteristics for all crashes as inputs, three logistic regression models are developed. In the logistic regression analyses total number of through lanes at an intersection is used as a surrogate measure to AADT per lane and also intersection type is introduced as a 'predictor' of crash type. The binary logistic regression analyses indicated, among other results, that at intersections with one-way roads, adverse weather conditions, older drivers and/or female drivers increase the likelihood of being at-fault at IMOD crashes. Similar factors associated with other groups of crashes (i.e., IMSD and IMPD) are also identified. These findings from the study may be used to develop specialized training programs by zooming in onto problematic intersections/maneuvers.
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Date Issued
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2006
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Identifier
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CFE0001208, ucf:46954
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0001208
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Title
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THE FINANCIAL DETERMINANTS OF COLLEGE FOOTBALL.
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Creator
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Adams, Mitchell, Schnitzlein, Charles, University of Central Florida
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Abstract / Description
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There is a certain tradition, pageantry, rivalry, and glory in college football. It is well known that college football can be a big time money maker and sometimes covers the costs of other athletic teams within a school. However, it is also recognized that many college football programs lose money or struggle to break even. Thus, there is tremendous variability that exists in the amount of resources a school may have and the outcomes in athletic success, while there is not always a one to...
Show moreThere is a certain tradition, pageantry, rivalry, and glory in college football. It is well known that college football can be a big time money maker and sometimes covers the costs of other athletic teams within a school. However, it is also recognized that many college football programs lose money or struggle to break even. Thus, there is tremendous variability that exists in the amount of resources a school may have and the outcomes in athletic success, while there is not always a one to one correspondence between the two. The purpose of this study is to examine and analyze the quantifiable determinants of success, considering both financial and non-financial variables. The pressure to win, and do so immediately; brand; and outdo other schools in the facility "arm's race" has reached unprecedented levels.
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Date Issued
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2013
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Identifier
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CFH0004524, ucf:45217
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFH0004524
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Title
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An Engineering Analytics Based Framework for Computational Advertising Systems.
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Creator
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Chen, Mengmeng, Rabelo, Luis, Lee, Gene, Keathley, Heather, Rahal, Ahmad, University of Central Florida
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Abstract / Description
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Engineering analytics is a multifaceted landscape with a diversity of analytics tools which comes from emerging fields such as big data, machine learning, and traditional operations research. Industrial engineering is capable to optimize complex process and systems using engineering analytics elements and the traditional components such as total quality management. This dissertation has proven that industrial engineering using engineering analytics can optimize the emerging area of...
Show moreEngineering analytics is a multifaceted landscape with a diversity of analytics tools which comes from emerging fields such as big data, machine learning, and traditional operations research. Industrial engineering is capable to optimize complex process and systems using engineering analytics elements and the traditional components such as total quality management. This dissertation has proven that industrial engineering using engineering analytics can optimize the emerging area of Computational Advertising. The key was to know the different fields very well and do the right selection. However, people first need to understand and be experts in the flow of the complex application of Computational Advertising and based on the characteristics of each step map the right field of Engineering analytics and traditional Industrial Engineering. Then build the apparatus and apply it to the respective problem in question.This dissertation consists of four research papers addressing the development of a framework to tame the complexity of computational advertising and improve its usage efficiency from an advertiser's viewpoint. This new framework and its respective systems architecture combine the use of support vector machines, Recurrent Neural Networks, Deep Learning Neural Networks, traditional neural networks, Game Theory/Auction Theory with Generative adversarial networks, and Web Engineering to optimize the computational advertising bidding process and achieve a higher rate of return. The system is validated with an actual case study with commercial providers such as Google AdWords and an advertiser's budget of several million dollars.
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Date Issued
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2018
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Identifier
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CFE0007319, ucf:52118
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0007319
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Title
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Total Ownership Cost Modeling of Technology Adoption Using System Dynamics: Implications for ERP Systems.
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Creator
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Esmaeilian, Behzad, Karwowski, Waldemar, Mollaghasemi, Mansooreh, Xanthopoulos, Petros, Ahram, Tareq, Kincaid, John, University of Central Florida
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Abstract / Description
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Investment in new technologies is considered by firms as a solution to improve their productivity, product and service quality and their competitive advantages in the global market. Unfortunately, not all technology adoption projects have met their intended objectives. The complexity of technology adoption along with little consideration of the long term cost of the technology, are among the factors that challenge companies while adopting a new technology. Companies often make new technology...
Show moreInvestment in new technologies is considered by firms as a solution to improve their productivity, product and service quality and their competitive advantages in the global market. Unfortunately, not all technology adoption projects have met their intended objectives. The complexity of technology adoption along with little consideration of the long term cost of the technology, are among the factors that challenge companies while adopting a new technology. Companies often make new technology adoption decision without enough attention to the total cost of the technology over its lifecycle. Sometimes poor decision making while adopting a new technology can result in substantial recurring loss impacts. Therefore, estimating the total cost of the technology is an important step in justifying the technology adoption. Total Ownership Cost (TOC) is a wildly-accepted financial metric which can be applied to study the costs associated with the new technology throughout its lifecycle. TOC helps companies analyze not only the acquisition and procurement cost of the technology, but also other cost components occurring over the technology usage and service stage. The point is that, technology adoption cost estimation is a complex process involving consideration of various aspects such as the maintenance cost, technology upgrade cost and the cost related to the human-resource. Assessing the association between the technology characteristics (technology upgrades over its life cycle, compatibility with other systems, technology life span, etc) and the TOC encompasses a high degree of complexity. The complexity exists because there are many factors affecting the cost over time. Sometimes decisions made today can have long lasting impact on the system costs and there is a lag between the time the decision is taken and when outcomes occur. An original contribution of this dissertation is development of a System Dynamics (SD) model to estimate the TOC associated with the new technology adoption. The SD model creates casual linkage and relationships among various aspects of the technology adoption process and allows decision makers to explore the impact of their decisions on the total cost that the technology brings into the company. The SD model presented in this dissertation composes of seven sub-models including (1) technology implementation efforts, (2) workforce training, (3) technology-related workforce hiring process, (4) preventive and corrective maintenance process, (5) technology upgrade, (6) impact of technology on system performance and (7) total ownership cost sub model. A case study of Enterprise Resource Planning (ERP) system adoption has been used to show the application of the SD model. The results of the model show that maintenance, upgrade and workforce hiring costs are among the major cost components in the ERP adoption case study presented in Chapter 4. The simulation SD model developed in this dissertation supports trade-off analysis and provides a tool for technology scenarios evaluation. The SD model presented here can be extended to provide a basis for developing a decision support system for technology evaluation.?
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Date Issued
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2013
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Identifier
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CFE0004836, ucf:49686
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004836
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Title
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The Moral Oppression of the Teaching Profession: Learning to Transcend.
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Creator
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Smith, Rebecca, Hewitt, Randall, Carter, Shannon, Terzian, Sevan, University of Central Florida
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Abstract / Description
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This thesis is both descriptive and philosophical, and at its core, it justifies the need for social foundations of education courses and programs in the university setting. It begins by analyzing the meaning of oppression and the part knowledge plays in confining the individual. The analysis then draws upon Patricia Hill Collins' theory of intersecting oppressions to get at the complexities and restrictions of working in the public schooling institution. It works through the ways in which...
Show moreThis thesis is both descriptive and philosophical, and at its core, it justifies the need for social foundations of education courses and programs in the university setting. It begins by analyzing the meaning of oppression and the part knowledge plays in confining the individual. The analysis then draws upon Patricia Hill Collins' theory of intersecting oppressions to get at the complexities and restrictions of working in the public schooling institution. It works through the ways in which sexist, classist, and racist practices afflict everyone in the institution through the bureaucratic mechanism and collateral oppression. The four components that make up the wires on the cage (gender, class, race, and bureaucracy) not only confine; they cause varying degrees of direct and indirect harms (psychological, emotional, moral, financial) to those on the inside. The concept of the institutional cage is then merged with Rodman Webb's work on schools as total institutions. Through an analysis on the characteristics of total institutions, it becomes apparent that standardization, technological developments, and the influence of venture philanthropy have brought schools more in-line with the total institution. The study then clarifies the ways in which corporatic, bureaucratic, and technocratic mentalities infect the institution, where they intersect, and how they restrict those within. The components coalesce into the conceptualization of moral oppression: the act of being coerced to ignore and suppress one's morality, moral impulses, and moral way of knowing. The remainder of the study explores the meaning of moral action and suggests some ways educators can let go of the ways of thinking and acting that may be keeping them from confidently doing what they know to be good and just.
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Date Issued
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2013
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Identifier
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CFE0004940, ucf:49621
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004940
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Title
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TOTAL BODY WATER AND ITS RELATIONSHIP TO FUNCTIONAL PERFORMANCE IN INDIVIDUALS WITH DIAGNOSED OSTEOARTHRITIS.
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Creator
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Hanson, Sara, Valdes, Anna, University of Central Florida
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Abstract / Description
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This study examines a possible relationship between Total Body Water (TBW) levels, osteoarthritic pain and functional performance in a sample of untrained adults. Participants will complete a Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire, TBW will be measured using Single-Frequency Bioelectrical Impedance (SF-BIA) and strength, balance and physical function will be measured by the completion of seven standardized functional tests. Participants in this study...
Show moreThis study examines a possible relationship between Total Body Water (TBW) levels, osteoarthritic pain and functional performance in a sample of untrained adults. Participants will complete a Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire, TBW will be measured using Single-Frequency Bioelectrical Impedance (SF-BIA) and strength, balance and physical function will be measured by the completion of seven standardized functional tests. Participants in this study will include adult men and women, age 35 years and older, who have been previously diagnosed with Osteoarthritis (OA) in the hip or knee, or currently score 35 or higher on the WOMAC. This study aims to determine if TBW values, specifically its intracellular compartment (ICW), will have a relationship to WOMAC scores and if TBW and ICW will have a positive correlation to participants' overall performance on balance, strength, and physical function tests. It is hypothesized that the data will show a negative correlation between ICW and WOMAC scores and a positive correlation between ICW and performance on balance, strength and physical function tests. Little research exists on the relationship between TBW and functional performance in older adults; particularly those whose TBW may be affected by inflammatory conditions such as OA. A goal of this study is to contribute to existing research on the relationship between performance and TBW, while providing insight and data on this relationship in an untrained population.
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Date Issued
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2015
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Identifier
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CFH0004741, ucf:45363
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFH0004741
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Title
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A System Dynamics Model for Manpower and Technology Implementation Trade-off and Cost Estimation.
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Creator
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Jiang, Hong, Karwowski, Waldemar, Kincaid, John, Reinerman, Lauren, Ahram, Tareq, University of Central Florida
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Abstract / Description
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The U.S. Navy has been confronted with budget cuts and constraints during recent years. This reduction in budget compels the U.S. Navy to limit the number of manpower and personnel to control costs. Reducing the total ownership cost (TOC) has become a major topic of interest for the Navy as plans are made for current and future fleets. According to the U.S. Government Accountability Office (GAO, 2003), manpower is the most influential component of determining the life cycle cost of a ship....
Show moreThe U.S. Navy has been confronted with budget cuts and constraints during recent years. This reduction in budget compels the U.S. Navy to limit the number of manpower and personnel to control costs. Reducing the total ownership cost (TOC) has become a major topic of interest for the Navy as plans are made for current and future fleets. According to the U.S. Government Accountability Office (GAO, 2003), manpower is the most influential component of determining the life cycle cost of a ship. The vast majority of the TOC is comprised of operating and support (O(&)S) costs which account for approximately 65 percent of the TOC. Manpower and personnel costs account for approximately 50 percent of O(&)S costs. This research focused on tradeoff analysis and cost estimation between manpower and new technology implementation. Utilizing concepts from System Dynamics Modeling (SDM), System Dynamics Causal Loop diagrams (CLD) were built to identify major factors when implementing new technology, and then stocks and flows diagrams were developed to estimate manpower cost associated with new technology implementation. The SDM base model reflected an 18 months period for technology implementation, and then compared different technology implementation for different scenarios. This model had been tested by the public data from Department of the Navy (DoN) Budget estimates.The objective of this research was to develop a SDM to estimate manpower cost and technology tradeoff analysis associated with different technology implementations. This research will assist Navy decision makers and program managers when objectively considering the impacts of technology selection on manpower and associated TOC, and will provide managers with a better understanding of hidden costs associated with new technology adoption. Recommendations were made for future study in manpower cost estimation of ship systems. In future studies, one particular type of data should be located to test the model for a specific manpower configuration.
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Date Issued
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2013
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Identifier
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CFE0004869, ucf:49662
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004869
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Title
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Crash quality- an approach for evaluating spending on quality improvement initiatives.
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Creator
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Ferreira, Labiche, Hosni, Yasser A., Engineering
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Abstract / Description
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University of Central Florida College of Engineering Thesis; The quality movement has become popular among corporations big and small for one reason: empirical evidence suggests that quality and productivity (and hence profitability) are linked. Unfortunately, while many firms accept that quality and productivity go together, few actually track the gains associated with their quality improvement programs. Companies also tend to spend on quality improvement with no indication of estimation of...
Show moreUniversity of Central Florida College of Engineering Thesis; The quality movement has become popular among corporations big and small for one reason: empirical evidence suggests that quality and productivity (and hence profitability) are linked. Unfortunately, while many firms accept that quality and productivity go together, few actually track the gains associated with their quality improvement programs. Companies also tend to spend on quality improvement with no indication of estimation of the impact of funding on the targeted process. It would be of great value to know: (1) the impact of spending to enhance the product/process quality level, and (2) the point at which expenditures for quality improvement are not economical. This research involves modeling the quality level of a product composed of integrated components/processes and the costs associated with quality improvement. Presented in this research is a methodology for determining the point at which the target quality level is reached. This point signifies when future spending should be re-directed. The research defines this point as the "Crash Quality Point (CQP)." Cases of a single process level and double level three-stage process are modeled to conceptualize CQP. The finding from the output analysis reveal that the quality level approaches the target level at varying points in time. Any spending beyond this point does not have an impact on the quality level compared to the period prior to the Crash Quality Point. Spending past this point is futile and these funds could be spent on the quality improvement projects. The special case modeled also illustrates the use of this tool in the selection of processes for improvements based on the quality level of the process. This is an added advantage in scenarios where funds are limited and management is constrained to improve process quality with limited funds. Using a real world example validates the proposed CQP methodology. The results of the validation indicate that the model developed can assist managers in forecasting the budget requirements for quality spending based on the quality improvement goals. The tool also enables managers to estimate the point in time at which allocations of funds may be directed for process reengineering. The CQP method will enable quality improvement professionals to determine the economical viability and the limits in expenditures on quality improvement. It enables managers to evaluate spending alternatives and approximate when the point of diminishing return is reached.
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Date Issued
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2000
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Identifier
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CFR0011594, ucf:53046
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFR0011594
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Title
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EVALUATION OF OXIDIZED MEDIA FILTRATION PROCESSES FOR THE TREATMENT OF HYDROGEN SULFIDE IN GROUNDWATER.
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Creator
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Trupiano, Vito, Duranceau, Steven, University of Central Florida
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Abstract / Description
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This study evaluated alternative sulfide treatment processes for potable water systems that rely on groundwater supplies. Research for this study was conducted at the Imperial Lakes (IL) and Turner Road (TR) water treatment plants (WTPs) in Polk County, Florida. These WTPs are in the process of refurbishment and expansion, and will require the installation of a new groundwater well. The IL and TR WTPs both rely upon groundwater sources that contain total sulfide at concentrations ranging from...
Show moreThis study evaluated alternative sulfide treatment processes for potable water systems that rely on groundwater supplies. Research for this study was conducted at the Imperial Lakes (IL) and Turner Road (TR) water treatment plants (WTPs) in Polk County, Florida. These WTPs are in the process of refurbishment and expansion, and will require the installation of a new groundwater well. The IL and TR WTPs both rely upon groundwater sources that contain total sulfide at concentrations ranging from 1.4 to 2.6 mg/L. Sulfide is a concern because if left untreated it can impact finished water quality, corrosivity, create undesirable taste and odor, and oxidize to form visible turbidity. For this reason, the raw water will require treatment per Florida Department of Environmental Protection (FDEP) "Sulfide Rule" 62-555.315(5)(a). This rule does not allow the use of conventional tray aeration (currently in use at the IL and TR WTPs) for wells that have significant total sulfide content (0.6 to 3.0 mg/L). This research was commissioned because the potential water treatment method identified in the Sulfide Rule (i.e. forced-draft aeration) would not adequately fit within the confines of the existing sites and would pose undue burden to neighboring residents. In addition, an effective sulfide treatment process was desired that offered a low profile, did not necessitate the need for additional complex chemical feed systems, minimized the extent of electrical infrastructure upgrades, and was inexpensive to construct and operate. To meet these goals, several alternative technologies were evaluated at the desktop and bench-scale; these included anion exchange, various oxidation methods, and alternative media filtration processes. From that effort, several processes were selected for evaluation at the pilot scale: bleach (NaOCl) oxidation preceding electromedia filtration; manganese (IV) oxide (MnO2) filtration continuously regenerated with bleach; and ferrate (Fe(VI)) oxidation. Electromedia and MnO2 filtration were shown to be effective for total sulfide treatment. Both processes reduced total sulfide content to below detection levels (< 0.1 mg/L) for groundwater supplies containing as much as 2.6 mg/L of total sulfide. The use of bleach oxidation ahead of media filtration also produced finished water with low turbidity (< 1.0 NTU) as compared to conventional tray aeration and chlorination processes (6-16 NTU, as observed in this study). It was determined that the media filtration approach (electromedia and MnO2) was effective for sulfide treatment and met the County's site objectives established at the outset of the project. Ferrate was also shown to reduce total sulfide content to below detection levels (< 0.1 mg/L) for groundwater supplies containing as much as 2.6 mg/L of total sulfide. An opinion of probable capital costs for installing a sulfide oxidation/filtration process at either the Imperial Lakes or Turner Road WTP was estimated to range from roughly $830,000 to $1,100,000. That equates to a $/kgal capital cost of $0.10 to $0.32 (at 8% for 20 years). An opinion of annual probable bleach chemical costs was estimated to range from $3,500 to $9,800 for the IL WTP and $3,500 to $5,800 for the TR WTP.
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Date Issued
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2010
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Identifier
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CFE0003370, ucf:48432
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0003370
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Title
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Integrated Data Fusion and Mining (IDFM) Technique for Monitoring Water Quality in Large and Small Lakes.
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Creator
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Vannah, Benjamin, Chang, Ni-bin, Wanielista, Martin, Wang, Dingbao, University of Central Florida
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Abstract / Description
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Monitoring water quality on a near-real-time basis to address water resources management and public health concerns in coupled natural systems and the built environment is by no means an easy task. Furthermore, this emerging societal challenge will continue to grow, due to the ever-increasing anthropogenic impacts upon surface waters. For example, urban growth and agricultural operations have led to an influx of nutrients into surface waters stimulating harmful algal bloom formation, and...
Show moreMonitoring water quality on a near-real-time basis to address water resources management and public health concerns in coupled natural systems and the built environment is by no means an easy task. Furthermore, this emerging societal challenge will continue to grow, due to the ever-increasing anthropogenic impacts upon surface waters. For example, urban growth and agricultural operations have led to an influx of nutrients into surface waters stimulating harmful algal bloom formation, and stormwater runoff from urban areas contributes to the accumulation of total organic carbon (TOC) in surface waters. TOC in surface waters is a known precursor of disinfection byproducts in drinking water treatment, and microcystin is a potent hepatotoxin produced by the bacteria Microcystis, which can form expansive algal blooms in eutrophied lakes. Due to the ecological impacts and human health hazards posed by TOC and microcystin, it is imperative that municipal decision makers and water treatment plant operators are equipped with a rapid and economical means to track and measure these substances.Remote sensing is an emergent solution for monitoring and measuring changes to the earth's environment. This technology allows for large regions anywhere on the globe to be observed on a frequent basis. This study demonstrates the prototype of a near-real-time early warning system using Integrated Data Fusion and Mining (IDFM) techniques with the aid of both multispectral (Landsat and MODIS) and hyperspectral (MERIS) satellite sensors to determine spatiotemporal distributions of TOC and microcystin. Landsat satellite imageries have high spatial resolution, but such application suffers from a long overpass interval of 16 days. On the other hand, free coarse resolution sensors with daily revisit times, such as MODIS, are incapable of providing detailed water quality information because of low spatial resolution. This issue can be resolved by using data or sensor fusion techniques, an instrumental part of IDFM, in which the high spatial resolution of Landsat and the high temporal resolution of MODIS imageries are fused and analyzed by a suite of regression models to optimally produce synthetic images with both high spatial and temporal resolutions. The same techniques are applied to the hyperspectral sensor MERIS with the aid of the MODIS ocean color bands to generate fused images with enhanced spatial, temporal, and spectral properties. The performance of the data mining models derived using fused hyperspectral and fused multispectral data are quantified using four statistical indices. The second task compared traditional two-band models against more powerful data mining models for TOC and microcystin prediction. The use of IDFM is illustrated for monitoring microcystin concentrations in Lake Erie (large lake), and it is applied for TOC monitoring in Harsha Lake (small lake). Analysis confirmed that data mining methods excelled beyond two-band models at accurately estimating TOC and microcystin concentrations in lakes, and the more detailed spectral reflectance data offered by hyperspectral sensors produced a noticeable increase in accuracy for the retrieval of water quality parameters.
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Date Issued
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2013
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Identifier
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CFE0005066, ucf:49979
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Format
-
Document (PDF)
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PURL
-
http://purl.flvc.org/ucf/fd/CFE0005066
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Title
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Design and Implementation of PV-Firming and Optimization Algorithms For Three-Port Microinverters.
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Creator
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Alharbi, Mahmood, Batarseh, Issa, Haralambous, Michael, Mikhael, Wasfy, Yuan, Jiann-Shiun, Kutkut, Nasser, University of Central Florida
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Abstract / Description
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With the demand increase for electricity, the ever-increasing awareness of environmental issues, coupled with rolling blackouts, the role of renewable energy generation is increasing along with the thirst for electricity and awareness of environmental issues. This dissertation proposes the design and implementation of PV-firming and optimization algorithms for three-port microinverters.Novel strategies are proposed in Chapters 3 and 4 for harvesting stable solar power in spite of intermittent...
Show moreWith the demand increase for electricity, the ever-increasing awareness of environmental issues, coupled with rolling blackouts, the role of renewable energy generation is increasing along with the thirst for electricity and awareness of environmental issues. This dissertation proposes the design and implementation of PV-firming and optimization algorithms for three-port microinverters.Novel strategies are proposed in Chapters 3 and 4 for harvesting stable solar power in spite of intermittent solar irradiance. PV firming is implemented using a panel-level three-port grid-tied PV microinverter system instead of the traditional high-power energy storage and management system at the utility scale. The microinverter system consists of a flyback converter and an H-bridge inverter/rectifier, with a battery connected to the DC-link. The key to these strategies lies in using static and dynamic algorithms to generate a smooth PV reference power. The outcomes are applied to various control methods to charge/discharge the battery so that a stable power generation profile is obtained. In addition, frequency-based optimization for the inverter stage is presented.One of the design parameters of grid-tied single-phase H-bridge sinusoidal pulse-width modulation (SPWM) microinverters is switching frequency. The selection of the switching frequency is a tradeoff between improving the power quality by reducing the total harmonic distortion (THD), and improving the efficiency by reducing the switching loss. In Chapter 5, two algorithms are proposed for optimizing both the power quality and the efficiency of the microinverter. They do this by using a frequency tracking technique that requires no hardware modification. The first algorithm tracks the optimal switching frequency for maximum efficiency at a given THD value. The second maximizes the power quality of the H-bridge micro-inverter by tracking the switching frequency that corresponds to the minimum THD.Real-time PV intermittency and usable capacity data were evaluated and then further analyzed in MATLAB/SIMULINK to validate the PV firming control. The proposed PV firming and optimization algorithms were experimentally verified, and the results evaluated. Finally, Chapter 6 provides a summary of key conclusions and future work to optimize the presented topology and algorithms.
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Date Issued
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2018
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Identifier
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CFE0007305, ucf:52166
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Format
-
Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0007305
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Title
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Integrating Spray Aeration and Granular Activated Carbon for Disinfection By-Product Control in a Potable Water System.
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Creator
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Rodriguez, Angela, Duranceau, Steven, Lee, Woo Hyoung, Sadmani, A H M Anwar, University of Central Florida
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Abstract / Description
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Public water systems add disinfectants in water treatment to inactivate microbial pathogens. Chlorine, when used as a disinfectant, reacts with natural organic matter in the water to form trihalomethane (THM) and haloacetic acid (HAA5) disinfection by-products (DBPs), which are suspected carcinogens. The Safe Drinking Water Act's Disinfectant and Disinfection By-Product (D/DBP) Rules were promulgated by the U.S. Environmental Protection Agency to regulate the amount of DBPs in water systems....
Show morePublic water systems add disinfectants in water treatment to inactivate microbial pathogens. Chlorine, when used as a disinfectant, reacts with natural organic matter in the water to form trihalomethane (THM) and haloacetic acid (HAA5) disinfection by-products (DBPs), which are suspected carcinogens. The Safe Drinking Water Act's Disinfectant and Disinfection By-Product (D/DBP) Rules were promulgated by the U.S. Environmental Protection Agency to regulate the amount of DBPs in water systems. Regulatory compliance is based on maximum contaminant levels (MCL), measured as a locational running annual average (LRAA), for total THM (TTHM) and HAA5 of 80 (&)#181;g/L and 60 (&)#181;g/L, respectively. Regulated DBPs, if consumed in excess of EPA's MCL standard over many years, may increase chronic health risks. In order to comply with the D/DBP Rules, the County of Maui Department of Water Supply (DWS) adopted two DBP control technologies. A GridBee(&)#174; spray-aeration process was place into DWS's Lower Kula water system's Brooks ground storage tank in February of 2013. In March of 2015 the second DBP control technology, granular activated carbon (GAC), was integrated into DWS's Pi'iholo surface water treatment plant. To investigate the integration effectiveness of GAC and spray-aeration into a water system for DBP control, DBP data was gathered from the system between August of 2011 and August 2016, and analyzed relative to cost and performance.Prior to the spray aeration and GAC integration, it was found that TTHM levels at the LRAA compliance site ranged between 58.5 (&)#181;g/L and 125 (&)#181;g/L (at times exceeding the MCL). Additionally, HAA5 levels at the LRAA compliance site ranged between 21.2 and 52.0 (&)#181;g/L. The concerted efforts of the GAC and GridBee(&)#174; system was found to reduce LRAA TTHM and HAA5 concentrations to 38.5 (&)#181;g/L and 20.5 (&)#181;g/L, respectively, in the Lower Kula system. Hypothesis testing utilizing t-Tests confirmed that TTHMs levels were controlled by the spray aeration system and the GAC was responsible for controlling HAA5 formation. Although TTHM levels were reduced by 58 percent, and HAA5 levels by 48 percent, the estimated cumulative annual operation and maintenance (O(&)M) cost of the two systems was $1,036,000. In light of the cost analysis, total organic carbon (TOC)-based models for predicting LRAA TTHM and HAA5 levels were developed as equation (i) and (ii), respectively:(i) TTHM (&)#181;g/L = (32.5 x (TOC ppm)) + 5.59, (ii) HAA5 (&)#181;g/L = (8.37 x (TOC ppm)) + 12.4.The TTHM model yielded an R2 of 0.93, and the HAA5 model had an R2 of 0.52. F-Tests comparing predicted LRAA TTHM and HAA5 levels to actual LRAA TTHM and HAA5 levels determined no statistically-significant difference. With the knowledge of how the GAC and spray aerator controlled DBPs in the water system, a cost-effective and practical treatment operating parameter was developed. The parameter, Pi'iholo water plant filter effluent TOC content, can serve as an indicator that operators would use to alter DBP treatment process flow set points to achieve cost-effective treatment. Furthermore, the significant annual cost contribution by the GAC, coupled with HAA5 levels below DWS's MCLG, led to the recommendation of variable frequency drive (VFD) pumps for the GAC system. The addition of VFD pumps should reduce the frequency of carbon change outs while preserving adequate HAA5 control in the system.
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Date Issued
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2016
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Identifier
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CFE0006841, ucf:52881
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Format
-
Document (PDF)
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PURL
-
http://purl.flvc.org/ucf/fd/CFE0006841
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Title
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Chemical Analysis, Databasing, and Statistical Analysis of Smokeless Powders for Forensic Application.
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Creator
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Dennis, Dana-Marie, Sigman, Michael, Campiglia, Andres, Yestrebsky, Cherie, Fookes, Barry, Ni, Liqiang, University of Central Florida
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Abstract / Description
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Smokeless powders are a set of energetic materials, known as low explosives, which are typically utilized for reloading ammunition. There are three types which differ in their primary energetic materials; where single base powders contain nitrocellulose as their primary energetic material, double and triple base powders contain nitroglycerin in addition to nitrocellulose, and triple base powders also contain nitroguanidine. Additional organic compounds, while not proprietary to specific...
Show moreSmokeless powders are a set of energetic materials, known as low explosives, which are typically utilized for reloading ammunition. There are three types which differ in their primary energetic materials; where single base powders contain nitrocellulose as their primary energetic material, double and triple base powders contain nitroglycerin in addition to nitrocellulose, and triple base powders also contain nitroguanidine. Additional organic compounds, while not proprietary to specific manufacturers, are added to the powders in varied ratios during the manufacturing process to optimize the ballistic performance of the powders. The additional compounds function as stabilizers, plasticizers, flash suppressants, deterrents, and opacifiers. Of the three smokeless powder types, single and double base powders are commercially available, and have been heavily utilized in the manufacture of improvised explosive devices.Forensic smokeless powder samples are currently analyzed using multiple analytical techniques. Combined microscopic, macroscopic, and instrumental techniques are used to evaluate the sample, and the information obtained is used to generate a list of potential distributors. Gas chromatography (-) mass spectrometry (GC-MS) is arguably the most useful of the instrumental techniques since it distinguishes single and double base powders, and provides additional information about the relative ratios of all the analytes present in the sample. However, forensic smokeless powder samples are still limited to being classified as either single or double base powders, based on the absence or presence of nitroglycerin, respectively. In this work, the goal was to develop statistically valid classes, beyond the single and double base designations, based on multiple organic compounds which are commonly encountered in commercial smokeless powders. Several chemometric techniques were applied to smokeless powder GC-MS data for determination of the classes, and for assignment of test samples to these novel classes. The total ion spectrum (TIS), which is calculated from the GC-MS data for each sample, is obtained by summing the intensities for each mass-to-charge (m/z) ratio across the entire chromatographic profile. A TIS matrix comprising data for 726 smokeless powder samples was subject to agglomerative hierarchical cluster (AHC) analysis, and six distinct classes were identified. Within each class, a single m/z ratio had the highest intensity for the majority of samples, though the m/z ratio was not always unique to the specific class. Based on these observations, a new classification method known as the Intense Ion Rule (IIR) was developed and used for the assignment of test samples to the AHC designated classes.Discriminant models were developed for assignment of test samples to the AHC designated classes using k-Nearest Neighbors (kNN) and linear and quadratic discriminant analyses (LDA and QDA, respectively). Each of the models were optimized using leave-one-out (LOO) and leave-group-out (LGO) cross-validation, and the performance of the models was evaluated by calculating correct classification rates for assignment of the cross-validation (CV) samples to the AHC designated classes. The optimized models were utilized to assign test samples to the AHC designated classes. Overall, the QDA LGO model achieved the highest correct classification rates for assignment of both the CV samples and the test samples to the AHC designated classes.In forensic application, the goal of an explosives analyst is to ascertain the manufacturer of a smokeless powder sample. In addition, knowledge about the probability of a forensic sample being produced by a specific manufacturer could potentially decrease the time invested by an analyst during investigation by providing a shorter list of potential manufacturers. In this work, Bayes' Theorem and Bayesian Networks were investigated as an additional tool to be utilized in forensic casework. Bayesian Networks were generated and used to calculate posterior probabilities of a test sample belonging to specific manufacturers. The networks were designed to include manufacturer controlled powder characteristics such as shape, color, and dimension; as well as, the relative intensities of the class associated ions determined from cluster analysis. Samples were predicted to belong to a manufacturer based on the highest posterior probability. Overall percent correct rates were determined by calculating the percentage of correct predictions; that is, where the known and predicted manufacturer were the same. The initial overall percent correct rate was 66%. The dimensions of the smokeless powders were added to the network as average diameter and average length nodes. Addition of average diameter and length resulted in an overall prediction rate of 70%.
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Date Issued
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2015
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Identifier
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CFE0005784, ucf:50059
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Format
-
Document (PDF)
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PURL
-
http://purl.flvc.org/ucf/fd/CFE0005784
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-
Title
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Trihalomethane Removal and Re-Formation in Spray Aeration Processes Treating Disinfected Groundwater.
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Creator
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Smith, Cassandra, Duranceau, Steven, Randall, Andrew, Lee, Woo Hyoung, University of Central Florida
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Abstract / Description
-
Historically, chlorination has been widely utilized as a primary and secondary disinfectant in municipal water supplies. Although chlorine disinfection is effective in inactivating pathogenic microbes, the use of chlorine creates the unintentional formation of regulated chemicals. On January 4, 2006, the United States Environmental Protection Agency (EPA) promulgated the Stage 2 Disinfectants/Disinfection by-product rule (DBPR) that focuses on public health protection by limiting exposure to...
Show moreHistorically, chlorination has been widely utilized as a primary and secondary disinfectant in municipal water supplies. Although chlorine disinfection is effective in inactivating pathogenic microbes, the use of chlorine creates the unintentional formation of regulated chemicals. On January 4, 2006, the United States Environmental Protection Agency (EPA) promulgated the Stage 2 Disinfectants/Disinfection by-product rule (DBPR) that focuses on public health protection by limiting exposure to four trihalomethanes (THM) and five haloacetic acids (HAA5), formed when chlorine is used for microbial pathogen control. This thesis examines post-aeration TTHM formation when employing spray-aeration processes to remove semi-volatile TTHMs from chlorinated potable water supplies.A bench scale air stripping unit was designed, constructed and operated to evaluate spray aeration for the removal of the four regulated trihalomethane (THM) species from potable drinking water including bromodichloromethane, bromoform, dibromochloromethane, chloroform. The study was conducted using finished bulk water samples collected from two different water treatment facilities (WTFs) located in Oviedo and Babson Park, Florida. Both treatment plants treat groundwater; however, Oviedo's Mitchell Hammock WTF (MHWTF) supply wells contain dissolved organic carbon and bromide DBP precursors whereas the Babson Park WTF #2 (BPWTF2) supply well contains dissolved organic carbon DBP precursors but is absent of bromide precursor. Three treatment scenarios were studied to monitor impacts on total trihalomethane (TTHM) removal and post-treatment (post-aeration) TTHM formation potential, including 1) no treatment (non-aerated control samples), 2) spray aeration via specially fabricated GridBee(&)#174; nozzle for laboratory-scale applications, 3) spray aeration via a commercially available manufactured BETE(&)#174; nozzle used for full-scale applications. Select water quality parameters, chlorine residual, and total trihalomethane concentrations were monitored throughout the study. The GridBee(&)#174; spray nozzle resulted in TTHM removals ranging from 45.2 (&)#177; 3.3% for the BPWTF2 samples, and 37.7 (&)#177; 3.1% for the MHWTF samples. The BETE(&)#174; spray nozzle removed 54.7(&)#177;3.9% and 48.1(&)#177;6.6% of total trihalomethanes for the Babson Park and Mitchell Hammock WTF samples, respectively. The lower percent removals at the MHWTF are attributed to the detectable presence of bromide and subsequent formation of hypobromous acid in the samples. Post spray aeration TTHM formation potentials were monitored and it was found that the MHWTF experienced significantly higher formation potentials, once again due to the presence of hypobromous acid which led to increases in overall TTHM formation over time in comparison with the Babson Park WTF #2 TTHM formation samples. In addition, chlorine residuals were maintained post spray aeration treatment, and initial chlorine residual and trihalomethane concentrations did not significantly impact overall spray nozzle performance. Among other findings, it was concluded that spray nozzle aeration is a feasible option for the Babson Park WTF #2 for TTHM compliance. For Oviedo's Mitchell Hammock WTF spray aeration was successful in removing TTHMs, however it was not effective in maintaining DBP rule compliance due to the excessive nature of DBP formation in the water samples. This study was not intended to serve as an assessment of varying nozzle technologies; rather, the focus was on the application of spray aerators for TTHM removal and post-formation in drinking water systems.
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Date Issued
-
2015
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Identifier
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CFE0005715, ucf:50117
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Format
-
Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0005715
Pages