Thesis (M.S.)--Mississippi State University. Department of Computer Science. / Title from title screen. Includes bibliographical references.

The durability of infrastructure components, such as prestressed concrete bridge beams, can be significantly affected by long-term deterioration associated with corrosion. Corrosion is a major concern for bridges in Virginia, due to the frequent use of deicing salts during the winter, as well as the number of structures in marine environments. The residual capacity of corrosion damaged prestressed I-beams and box beams needs to be accurately estimated to determine if damaged bridges need to be posted, and to help with making informed decisions related to repair, rehabilitation and replacement of damaged bridges. The initial stage of the research investigated the ability to determine the in-situ strength of members that have visible corrosion-related damage. In this stage, six corrosion-damaged beams were investigated. Prior to testing, the beams were visually inspected and damage was documented. The beams were then tested in the lab to determine their flexural strength. Following testing, samples of strands were removed and tested to determine their tensile properties while cores were taken to determine compressive strength. Powdered concrete samples were removed to perform chloride concentration tests. The tested strengths of the beams were compared to calculated strengths using two methods for damage estimation and two different calculation approaches. Two repair methods were then evaluated through large-scale experimental testing, aimed at restoring the strength of deteriorated prestressed concrete beams. The investigated repairs included External Post-Tensioning (PT) and Carbon Fiber Reinforced Polymer (CFRP) laminates applied to the bottom flange of beams for flexural strengthening. A total of five full-scale bridge members were tested to failure throughout this stage. All beams were subjected to monotonically increasing loads until failure. For beams repaired with external PT, the experimental test was accompanied by a detailed approach for determining the ultimate failure load, the ultimate stress in the external tendons, and the location of the failure. For beams repaired with CFRP, the experimental test was accompanied by a parametric study that was performed to determine the maximum reduction in flexural strength for which CFRP can be considered as a viable repair method to restore the lost capacity. This dissertation provides additional information on estimating the residual capacity of corrosion-damaged beams and shows the types of repair that can restore their original strength. With this information, Departments of Transportation (DOT) can properly determine what types of repair are a suitable for the damaged girders based on their level of corrosion. / Doctor of Philosophy / Many bridges in the United States were built using longitudinal members, called girders, made of prestressed concrete. In prestressed concrete, because concrete cannot resist high tensile forces, tensioned steel cables, called strands, are used to produce compression on the concrete member to improve its behavior when it is in service. Corrosion induces cracks in the concrete superstructure which accelerates the deterioration rate and can result in a partial loss of the concrete body and exposure of the embedded steel. This causes degradation in the load-carrying capacity of the bridge girders which raises a danger to vehicles, passengers, and pedestrians. The residual capacity of corrosion damaged prestressed I-beams and box beams needs to be accurately estimated to determine if damaged bridges need to be posted, and to help with making informed decisions related to repair, rehabilitation and replacement of damaged bridges. The initial stage of the research investigated the ability to determine the in-situ strength of members that have visible corrosion-related damage. In this stage, six corrosion-damaged beams were investigated. Prior to testing, the beams were visually inspected, and damage was documented. The beams were then tested in the lab. Following testing, samples of strands were removed and tested to determine their tensile properties while cores were taken to determine compressive strength. Powdered concrete samples were removed to perform chloride concentration tests. The tested strengths of the beams were compared to calculated strengths. Two repair methods were then evaluated through large-scale experimental testing, aimed at restoring the strength of deteriorated prestressed concrete beams. The investigated repairs included External Post-Tensioning (PT) and Carbon Fiber Reinforced Polymer (CFRP) sheets applied to the bottom of beams for flexural strengthening. A total of five full-scale bridge members were tested to failure throughout this stage. All beams were subjected to monotonically increasing loads until failure. For beams repaired with external PT, the experimental test was accompanied by a detailed approach for determining the ultimate failure load, the ultimate stress in the external tendons, and the location of the failure. For beams repaired with CFRP, the experimental test was accompanied by a parametric study that was performed to determine the maximum reduction in flexural strength for which CFRP can be considered as a viable repair method to restore the lost capacity. This dissertation provides additional information on estimating the residual capacity of corrosion-damaged beams and shows the types of repair that can restore their original strength. With this information, Departments of Transportation (DOT) can properly determine what types of repair are a suitable for the damaged girders based on their level of corrosion.

Corrosion is a concern in old prestressed concrete bridges, especially bridges built in marine environments. Corrosion induces cracks in the concrete superstructure which accelerates the deterioration rate and can result in a complete loss of the concrete cover and exposure of the reinforcing and prestressing steel. This causes degradation in the load-carrying capacity of the bridge girders. Consequently, decisions need to be made on whether to replace, retrofit, or load post these bridges. Extensive research has focused on the flexural strength of corroded prestressed concrete girders. This research studies the shear strength of corroded prestressed concrete girders which can, then, be expanded further to evaluate the possible retrofitting techniques for restoring, or enhancing, their shear strengths. Two old prestressed concrete girders built in the 1960's and 1970's were delivered to the Murray Structural Engineering Laboratory at Virginia Tech from two decommissioned bridges in Virginia. The two girders showed signs of deterioration due to corrosion. Non-destructive testing was performed to evaluate their in-situ conditions. For both girders, each end was tested in the lab in three-point loading condition to make full use of the girders. Shear capacities of the girders were predicted using four methods in the current AASHTO LRFD and the ACI codes. In addition, analysis using Response2000 and strut-and-tie modelling were also carried out. Evaluation of these methods and comparisons with the experimental results were performed to reach to conclusions and recommendations for future work. Corrosion in strands seemed to not have as much influence on the shear capacity as on the flexural capacity. Destructive shear tests indicated that the actual shear capacities of the girders investigated in this research exceeded nominal capacities predicted by the current codes. However, the flexural capacities were reduced. Possible reasons for the girders' behaviors are discussed. / Master of Science / Many bridges in the United States were built using longitudinal members, called girders, made of prestressed concrete. In prestressed concrete, because concrete cannot resist high tensile forces, tensioned steel cables, called strands, are used to produce compression on the concrete member to improve its behavior when it is in service. Corrosion is a concern in old prestressed concrete bridges, especially bridges built in marine environments. Corrosion induces cracks in the concrete superstructure which accelerates the deterioration rate and can result in a partial loss of the concrete body and exposure of the embedded steel. This causes degradation in the load-carrying capacity of the bridge girders which raises a danger to vehicles, passengers, and pedestrians. Consequently, decisions need to be made by authorities on whether to replace, repair, or load post these bridges. Two main types of loads exist in bridge girders, namely shear forces and bending moments. Extensive research has focused on the ability of corroded prestressed concrete girders to resist stresses produced by moment, or flexure. However, bridge girders must also resist shear forces. This research studies the shear strength of corroded prestressed concrete girders which can, then, be expanded further to evaluate the possible retrofitting techniques for restoring, or enhancing, their shear strengths. Two old prestressed concrete girders built in the 1960's and 1970's were delivered to the Murray Structural Engineering Laboratory at Virginia Tech from two decommissioned bridges in Virginia. The two girders showed signs of deterioration due to corrosion. These signs include concrete losses, cracks, areas of unsound concrete, and exposed strands. Non-destructive testing was performed on the girders to evaluate the severity of their in-situ conditions. Then, two destructive full-scale tests were performed on each girder in the lab to estimate their actual shear strengths. Shear strengths of the girders were also predicted using four methods present in the current American Association of State Highway and Transportation Officials, AASHTO, and the American Concrete Institute, ACI, codes. In addition, analyses using other advanced tools were also carried out. Evaluation of these methods and comparisons with the experimental results were performed to reach to conclusions and recommendations for future work. Corrosion in strands seemed to not have as much influence on the shear strength as on the flexural strength. Destructive shear tests indicated that the actual shear strengths of the girders investigated in this research exceeded nominal strengths predicted by the current codes, the AASHTO and the ACI. However, the flexural strengths were reduced. Possible reasons for the girders' behaviors are discussed.

The aim of the thesis is solving the new building of the Faculty of Fine Arts in Brno. The studied area is located on the borders of the city of Brno-Center and Brno-Žabovřesky. Define the plot street Veveří, Bulínova, Academická, Hrnčířská and Šumavská. Žabovřesky. Define the plot street Veveří, Bulínová, Academic, Pottery and Šumavská. The proposal involves two universities - the Faculty of Arts and Faculty of Forensic Engineering. The proposal builds on a new urban plan for the city of Brno, and also reflects the design of the new underground tram Diameter. The building complex is designed as a whole. The buildings of these schools have certain common facilities, such as a library, cloakroom, dining room, hall, utility room. The proposal builds on the competition program at the Academic square in Brno. Parking is solved as an underground garage. Outside parking spaces for both faculties be reckoned with parking spaces for the City, and to be a substitute for the parking areas located on the currently designed plot. The proposed solution allows to stage construction, where the first stage will be built Faculty of Forensic Engineering, common areas, all the parking spaces and the second stage will be built Faculty of Fine Arts.

Thesis deals with problems of forensic technical analysis of traffic accidents, concretely with creation of complex methodology for analysis of traffic accidents of vehicles on the crossroad. There are defined terms of "complex system and complex analysis of traffic accident", technically acceptable range of important input values, systematization of accidents on the crossroad with methodologies in the thesis. Thesis shows problematical expert procedures, suggests scheme of expert evidence and includes methodology of measurement of common movement of vehicles on the crossroad and recommendation for expert procedures.

Problems exist with ethical decision-making in U.S. construction engineering projects. The purpose of this study was to explore factors that affect ethical decision-making in engineering construction in the United States. The general concepts of marketing ethics, Kohlberg's discussion of ethical and moral reasoning development, and Gillian's discussion of ethical care served as the basis of the conceptual framework. Factors that inhibit ethical decision making were addressed in the research questions. The resulting narrative framework included implementable initiatives based on these factors that could improve the quality of ethical decision-making and the impact of these initiatives on the cost and quality of construction engineering projects. The use of qualitative grounded theory design led to findings from the research questions and enabled the development of a theory to explain the phenomenon. The research was based on data collected from interviews with a purposive sample of 12 civil engineers with 15 to 45 years of forensic and managerial experience with construction engineering projects. The constant comparative method was used to analyze the data. The principal finding from the research was that unethical decision-making in the legal and political systems undermines the image and authority of construction engineers in the United States. The findings of the study may cause social change by indicating how to enhance the ethical behavior of individuals involved in decision-making within the U.S. construction engineering industry, leading to improvements in the cost and quality of construction projects that benefit individual stakeholders as well as society.

The traditional approach to a digital investigation when a computer system is encountered in a running state is to remove the power, image the machine using a write blocker and then analyse the acquired image. This has the advantage of preserving the contents of the computer’s hard disk at that point in time. However, the disadvantage of this approach is that the preservation of the disk is at the expense of volatile data such as that stored in memory, which does not remain once the power is disconnected. There are an increasing number of situations where this traditional approach of ‘pulling the plug’ is not ideal since volatile data is relevant to the investigation; one of these situations is when the machine under investigation is using encryption. If encrypted data is encountered on a live machine, a live investigation can be performed to preserve this evidence in a form that can be later analysed. However, there are a number of difficulties with using evidence obtained from live investigations that may cause the reliability of such evidence to be questioned. This research investigates whether digital evidence obtained from live investigations involving encryption can be considered to be reliable. To determine this, a means of assessing reliability is established, which involves evaluating digital evidence against a set of criteria; evidence should be authentic, accurate and complete. This research considers how traditional digital investigations satisfy these requirements and then determines the extent to which evidence from live investigations involving encryption can satisfy the same criteria. This research concludes that it is possible for live digital evidence to be considered to be reliable, but that reliability of digital evidence ultimately depends on the specific investigation and the importance of the decision being made. However, the research provides structured criteria that allow the reliability of digital evidence to be assessed, demonstrates the use of these criteria in the context of live digital investigations involving encryption, and shows the extent to which each can currently be met.

The theme of the thesis is a study of the project of the Faculty of Fine Arts in Brno. The site lies on boundary of two city parts, Brno – Střed and Brno – Žabovřesky and it is surrounded by streets Veveří, Šumavská and Bulínova.The project ties together with architectural study from subject TG02, which concerns the Faculty of Forensic Engineering. The final result of both parts is the project of both schools with common facilities. The part of the project is an underground garage where is a space for public parking which is demanded by city hall. The main idea was to create building with respect to surroundings and define itself to the street lines and create the small square inside the block of the buildings. The results are two six-floor buildings connected by two-floor object with atrium.

Indiana University-Purdue University Indianapolis (IUPUI) / Canines are regularly utilized by law enforcement agencies to detect explosives. However, the mechanism by which canines respond to explosive vapors is not well understood, leading to difficulties in canine training and testing. It is known that the amount of vapor generated from explosive compounds is dependent upon several factors including sample amount, vapor pressure, and the degree of confinement. Underlying these factors is the basic process of evaporation of an unconfined explosive, which is rucial to understanding how explosive vapors behave in other, more confined, systems. In Stage One of this study, evaporation rates were determined for several explosive liquids using an analytical balance. These rates were compared to one another as well as to theoretical models for the evaporation of liquids. In general and as expected, mass decreased linearly with time and evaporation rates decreased logarithmically as boiling point increased. Several examples of solvent “pinning” on a metal surface were also observed. While an empirical model for the evaporation of unconfined explosive liquids was developed, a comprehensive model for the escape of explosive vapors from sealed containers (i.e., a suitcase, knapsack, or IED container itself) is needed. The second part of Stage One of this study was to determine that the flow rate of explosive vapors escaping from relatively large orifices does not conform to Fick’s Law of Diffusion. Fick’s model states that the flow rate is linearly dependent upon the cross sectional area of the orifice and the material’s diffusion coefficient. Instead, the flow rate was found to be linearly dependent upon the diameter of the orifice due to the tendency of the flow to diffuse outwards from its circular edge. A clear relationship between flow rate and diffusion coefficient was seen, however. Additional uncertainty arises concerning the complexity of the odor generated from explosive compounds. Because explosive vapors are often complex (they consist of multiple chemical compounds), confusion exists regarding the cause of canine alert; that is the “odor compound” that allows for canine detection of various explosives. Although 2, 4- dinitrotoluene (DNT) has been explored as a potential odor compound, the possibility of a nitrated explosive inherently producing nitrated gas upon decomposition has not. Stage Two of this study focused on evaluating nitrate as a potential cause of canine alerts. An LC/MS method for the detection of nitrate ions in Composition C-4 and flake trinitrotoluene (TNT) was developed and tested. Instrumental analysis was not successful in detecting nitrate ions in any of the explosives tested. The lack of nitrate was confirmed using a diphenylamine color test for nitrates, thus eliminating nitrate as an odor compound and cause of canine alert to nitroaromatic compounds. 2, 4-DNT has been introduced as a potential odor compound of TNT, however, the mechanisms behind its vapor emission have not been thoroughly explored. More specifically, due to the “sticky” nature of the 2, 4-DNT isomer, the effects of surface adhesion to container walls are of concern. In particular, whether the amount of material lost to surface adhesion is significant enough to effect canine detection of TNT. A second focus of Stage Two explored this concern. A GC/MS method for the detection and separation of TNT and DNT isomers in liquid extracts was developed and the amount of 2, 4-DNT residues adhering to container walls was quantified. These values, compared to the amount 2,4-DNT expected to saturate each container (determined by the Ideal Gas Law), showed a significant preference of 2,4-DNT in the solid phase as opposed to in the gas phase. The amount of residue adhering to the walls of a gallon can differed from expected values by nearly 70%. The amount of material extracted from a quart can exceeded expected values by 137%. The apparent sticky nature of 2, 4-DNT resulted in a significant loss of material needed to fully saturate a container and thus canine detection success may be affected. In the final stage of this study, theories regarding odor compounds and odor availability of nitromethane, TNT, and Composition C-4 were tested using certified explosives-detecting canines. These trials included thirty-three canine-handler teams from eight government agencies. The odor availability of nitromethane was tested by placing varying volumes of nitromethane in containers with differing degrees of confinement and studying the effects on canine detection success. The odor availability trial showed no significant effect of sample amount or degree of confinement on canine detection so long as the sample volume was sufficient to saturate its container. In this study that volume was determined to be < 1 mL. Detection of 2, 4-DNT, TNT-NESST (Non-Hazardous Explosives for Security Training and Testing), and flake TNT were also studied using certified canines. The purpose of this was to identify the odorant responsible for canine alert to the explosive TNT. These trials showed a significant response to 2, 4-DNT compared to TNT and its training aid; this suggests that 2, 4-DNT is the primary cause of canine alerts to TNT. Additionally, Composition C-4 and RDX-NESTT were tested along with potential odor compounds that included the manufacturing solvent, cyclohexanone, the energetic “taggant” 2, 3-dimethyl-2.3-dinitrobutane (DMNB), the plasticizer dioctyladipate (DOA) and its degradation product 2-ethyl-1-hexanol. While some response to DMNB and cyclohexanone was seen, the most significant response was to the actual Composition C-4. This suggests that the cause of canine alert to Composition C-4 is the explosive mixture as a whole and not a single chemical component of the mixture

[pt] É apresentado um procedimento para simulação de colisões de veículos terrestres deformáveis, cuja entrada são as condições imediatamente anteriores ao choque, produzindo como saída a evolução das variáveis ao longo do tempo de duração do impacto. Foram feitas simulações de casos semelhantes aos apresentados na literatura, e os resultados obtidos validaram os modelos criados. O procedimento foi implementado em Simulink/MatLab, seguindo a mesma estrutura dos demais programas em desenvolvimento nesta linha de pesquisa, de modo a futuramente integrá-lo aos pré- processadores e pós-processadores gráficos do programa SVDV - Simulação e Visualização da Dinâmica de Veículos. / [en] A procedure for the simulation of flexible ground vehicles collisions is presented, which uses the conditions at the instant just before the impact as input variables and the evolution of the dynamic variables during the collision as output. Various simulations are presented and compared to similar cases found in the literature, what validates the proposed models. The algorithm was implemented using Simulink/Matlab software and used the same structure of the other programs under development in this area, in order to integrate it to graphic pre-processors and post-processors available in SVDV program - Simulation and Visualization of Vehicle Dynamics.