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- Title
- RECONFIGURABLE ANALOG FRONT-END SYSTEM FOR ULTRASONIC IMAGING APPLICATIONS
- Creator
- Vasudevan, Vidya
- Date
- 2014, 2014-12
- Description
-
Ultrasonic systems, applied in the field of Medical Imaging and Non-Destructive Testing, have evolved from the trolley-based units to more...
Show moreUltrasonic systems, applied in the field of Medical Imaging and Non-Destructive Testing, have evolved from the trolley-based units to more portable, hand-held devices. These systems are built to suit a specific application or aim at specific target material. In order to make these systems portable and adaptable to the testing environment, a flexible and programmable hardware is built. A fully configurable Analog Front-End (AFE) is presented, which possesses the capability for dynamic re-configuration by using ARM processing core for real-time control, data acquisition and signal analysis in a Linux environment. This system supports up to 8 ultrasonic sensors. The flexibility built into the AFE allows for various beamforming and signal conditioning requirements. This reconfigurable system enables ultrasonic researchers to efficiently prototype different experiments and to incorporate high performance ultrasonic signal and image processing algorithms. This system provides real-time signal processing for nondestructive evaluation (NDE) and imaging applications using ultrasonic sensors ranging from 60 KHz to 15 MHz operating frequencies. A dynamically reconfigurable sensor interface is presented for ultrasonic pulse-echo measurements targeting flaw detection and parametric echo classification applications. For real-time implementation, a SoC-based system is developed on an ARM platform. For a working system, a BCM2835 SoC on a Raspberry Pi hardware system is explored with a further upgrade to Xilinx Zynq 7020 SoC in order to achieve a higher throughput.
M.S. in Electrical Engineering, December 2014
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- Title
- Test of slender wooden struts for aeroplanes
- Creator
- Smith, M. A,, Kellener, W. A., Stevens, W. A.
- Date
- 2009, 1910
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/testofslenderwoo00smit
Thesis (B.S.)--Armour Institute of Technology
- Title
- A CONCEPTUAL SOLAR CHIMNEY PLANT AND FLORAL FARM USING ETFE AND BAMBOO
- Creator
- De Vita, Niels
- Date
- 2012-11-20, 2012-12
- Description
-
Motivated by a desire to create an architectural response to the environmental and social challenges of today, the following thesis project...
Show moreMotivated by a desire to create an architectural response to the environmental and social challenges of today, the following thesis project attempts to offer new paths for the future development of the solar chimney energy plant concept originally developed by the German engineer Jӧrg Schlaich in the early 1980s. The starting point of this thesis was to analyze the solar chimney prototype completed in the Manzanares desert in 1982 in order to understand the parameters guiding the design. The analysis allowed me to better understand the potential of the concept and to recognize the opportunity that existed to push the technological boundaries to craft a new design that reflects the current socio-political, economical and environmental context we live in. In the following pages, I attempt to demonstrate that the concept could be made even more appealing through the use of technology and locally available resources. By doing this, I seek to reinvigorate the idea, opening paths for a new conversation about the potential of the project as a social agent for progress. Throughout this thesis, I remain respectful and aware of the accomplishments of the pioneers before me, simply taking cues from their work to suggest new alternatives and solutions to a problem that has been made even more pressing due to the world’s energy crisis and economic uncertainty.
M.S. in Architecture, December 2012
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- Title
- THE CHANGE OF KURTOSIS IN IMPORTANCE SAMPLING FOR MONTE CARLO
- Creator
- Zhang, Xiaodong
- Date
- 2013, 2013-12
- Description
-
The Mont e Carlo (II IC) Method is commonly used to approximat e mult ivariat e integrals, which can be interpreted as means of random variab...
Show moreThe Mont e Carlo (II IC) Method is commonly used to approximat e mult ivariat e integrals, which can be interpreted as means of random variab les. The IIIC method uses th e sample mean to estimate the tr ue mean. In this thesis, we focus on minimizing th e sample size in MC simulat ion needed to sat isfy the specified error tolerance. Based on t he algorithm proposed by [5], we explain that t he cost of reliable IIIe est imat ion depends not only on variance but also on kurtosis. T herefore, when we try to improve th e efficiency of MC simulation by reducing variance, such as with Importance Sampling (IS), we need also look into the change of kurtosis. We analyze the change of cost in terms of the change of kur tosis and the change of variance. For a special case of IS we explore how to find th e optimal density in order to reduce variance.
M.S. in Applied Mathematics, December 2013
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- Title
- Juvenile Treatment Center
- Creator
- Cueva, Hernan
- Date
- 2010-07-29
- Title
- Investigation of Fresh Produce Washing on E. Coli O157:H7 and Murine Norovirus with Peroxyacetic Acid and High Power Ultrasound
- Creator
- Yuan, Wen
- Date
- 2011-12-05, 2011-12
- Description
-
E. coli O157:H7 and norovirus have each been responsible for outbreaks of foodborne illness involving fresh leafy green vegetables....
Show moreE. coli O157:H7 and norovirus have each been responsible for outbreaks of foodborne illness involving fresh leafy green vegetables. Peroxyacetic acid (POAA) has the potential to be an effective sanitizer during commercial fresh-cut produce washing. The addition of high power ultrasound (HPU) to the washing system may enhance the POAA efficacy. The purpose of this study was to reduce E. coli O157:H7 and norovirus contamination during commercial fresh-cut lettuce washing using POAA and HPU. Fresh-cut romaine lettuce leaves were inoculated with E. coli O157:H7 or murine norovirus (MNV, a surrogate for the human norovirus) and washed by POAA and HPU. Cross-contamination was tested by washing clean leaves in contaminated processing water where pre-inoculated leaves were washed previously. A high level of cross-contamination (4.5-log CFU/g E. coli) occurred after uninoculated leaves were rinsed in contaminated wash water for 2 min. A subsequent 2 min wash in POAA alone or in combination with HPU reduced counts by approximately 1.2-log and 2.3-log, respectively. More than 2-log norovirus was removed from washing 2 min in either DI water or POAA. However infectious MNV washed from leaves was not detected in wash water containing POAA. Those results implied a high possibility of cross-contamination during freshproduce washing, and indicate that adding POAA and HPU in addition to washing water in wash water can reduce cross-contamination rate.
M.S. in Food Safety and Technology, December 2011
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- Title
- Study of the action of a four inch grinnell variable pressure alarm valve
- Creator
- Hotchkin, E. W., Pfaelzer, F. M
- Date
- 2009, 1910
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/studyofactionoff00hotc
Thesis (B.S.)--Armour Institute of Technology, 1910 B.S. in Fire Protection Engineering,...
Show morehttp://www.archive.org/details/studyofactionoff00hotc
Thesis (B.S.)--Armour Institute of Technology, 1910 B.S. in Fire Protection Engineering, 1910
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- Title
- COATING OF BORON NITRIDE THIN FILM ON TITANIUM
- Creator
- Huang, Mairui
- Date
- 2013, 2013-12
- Description
-
To improve the wear resistance of titanium and extend its service life, coating boron nitride thin films on the surface of titanium matrix was...
Show moreTo improve the wear resistance of titanium and extend its service life, coating boron nitride thin films on the surface of titanium matrix was studied in this work. To obtain surface property enhancement, the samples were coated by isothermal sintering at 1000°C – 1400°C in a vacuum furnace for 2h, 4h or 6h. The microstructure of the thin film was investigated employing X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). To identify the composition of interlayers between BN and Ti, EDS analysis was run through the whole reaction zone. It showed that the BN was being consumed, titanium borides (TiB and TiB2), titanium nitride (TiN1-x), and solid solution of nitrogen in titanium (α-Ti (N)) layers formed at the interface between the BN coating and Ti matrix. Correspondingly, the XRD analysis indicated that TiB, TiB2, TiN, and α-Ti(N) phases were presented in good agreement with the EDS result. The layers grew fast in the sintering process which benefited from the fine grain size and highly oriented layers grown in the reaction zone. However, the well-known parabolic diffusional growth is only part of mechanisms for explaining the reactiondiffusion kinetics. The diffusion paths were obtained from the phase sequences at the interface between BN and Ti and thus could be represented on the isothermal section of the B-N-Ti ternary diagram. Moreover, the influence of the sintering temperature and the length of the actual sintering period on the layer sequences and thickness of the reaction zone were investigated. The micro-hardness test results showed that the Ti matrix with deposited BN thin films exhibited significant increased surface hardness. Obviously, the surface hardness xiii rose along with sintering temperature and holding time, and the hardness could be improved over 50%.
M.S. in Materials Science and Engineering, December 2013
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- Title
- SIMULATING THE HESTON MODEL VIA THE QE METHOD WITH A SPECIFIED ERROR TOLERANCE
- Creator
- Zhao, Xiaoyang
- Date
- 2017, 2017-05
- Description
-
The Quadratic Exponential (QE) model is a market standard simulation method for the Heston stochastic volatility model. We identify certain...
Show moreThe Quadratic Exponential (QE) model is a market standard simulation method for the Heston stochastic volatility model. We identify certain numerical problems with the standard discretization and modify the original method to correct these problems. We implement our modified QE scheme for the Heston model in the Guaranteed Automatic Integration Library (GAIL)|a suite of algorithms that includes Monte Carlo and quasi-Monte Carlo methods for multidimensional integration and computation of means. GAIL computes answers to satisfy user-defined error tolerances. We also implement variance reduction techniques for our modified QE scheme in GAIL. The numerical results show that our modified scheme is fast and accurate, and satisfies the user-defined error tolerances.
M.S. in Applied Mathematics, May 2017
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- Title
- THE RELATIONSHIP BETWEEN WORK-FAMILY CONFLICT, SOCIAL SUPPORT AND PERFORMANCE AMONG HEALTHCARE MANAGERS
- Creator
- Hunt, Mary K.
- Date
- 2011-05-16, 2011-05
- Description
-
As high performers are of great value in all organizations, understanding factors influencing their ability to maintain strong performance can...
Show moreAs high performers are of great value in all organizations, understanding factors influencing their ability to maintain strong performance can have useful implications for leaders. This study examines the relationship between employees’ performance, their stressors and coping approaches as defined by work-family conflict and perception and enactment of social support. Three hundred and twelve managers in a healthcare organization were categorized based on their performance in the year prior to the study. Results showed that high performers had higher satisfaction and use of supervisor support than moderate performers. The more satisfied managers were with support from their supervisor, coworkers, and friends, the less they reported work-family conflict. Satisfaction and use of support from friends influenced both work-to-family and family-to- work conflict.
M.S. in Psychology, May 2011
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- Title
- SEISMIC STRUCTURAL ANALYSIS USING INTERVAL GROUND MOTION
- Creator
- Venezia, Adam
- Date
- 2011-12-05, 2011-12
- Description
-
Seismic analysis is a crucial procedure for the design of a structure subjected to ground motion. In conventional seismic analysis procedures,...
Show moreSeismic analysis is a crucial procedure for the design of a structure subjected to ground motion. In conventional seismic analysis procedures, a structure is subjected to a limited number of earthquake excitations. Moreover, these procedures do not consider the presence of variations and uncertainties in those excitations. Interval analysis is one method capable of accounting for both of these limitations. In this work, a new method for seismic structural analysis, with interval uncertainty in the response spectrum, is developed, which is capable of obtaining the bounds of the dynamic response of a structure. This method is hereinafter referred to as Interval Ground Motion Analysis (IGMA). In this method, first, various response spectra are combined as an interval function, referred to as an interval response spectrum. Then, the response spectrum analysis is performed using the developed interval response spectrum, and the bounds of the dynamic response of the structure are obtained. It is shown that obtaining these bounds is computationally feasible and does not require iterative procedures such as Monte Carlo simulation. Numerical example problems, which illustrate the developed algorithm, are presented, along with a comparison of solutions obtained by another solution method.
M.S. in Civil Engineering, December 2011
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- Title
- CONGESTION CONTROL AND PACKET REORDERING FOR MULTIPATH TRANSMISSION CONTROL PROTOCOL
- Creator
- Ghose, Nirnimesh
- Date
- 2012-04-20, 2012-05
- Description
-
Modern devices are equipped with multiple network interfaces. Traditionally, only one of these is in use at any given time. However,...
Show moreModern devices are equipped with multiple network interfaces. Traditionally, only one of these is in use at any given time. However, simultaneous use of these mul- tiple interfaces will lead to better user experience. Support for this multi-interface scenario has led to the development of Multipath Transmission Control Protocol or MPTCP. MPTCP, as proposed by the IETF working group mptcp, allows a single data stream to be split across multiple paths. This has obvious benefits for reliability, and it can also lead to more efficient use of network resources. But a major problem in MPTCP is the congestion control and the eventual packet reordering at the desti- nation. Various techniques for congestion control for MPTCP have been given, but the packet reordering at the destination is not considered. Efficient packet reordering schemes can drastically improve the throughput for the MPTCP protocol. Therefore, in this work various available packet reordering techniques available for single path TCP are tested in the multipath situation. These algorithms are Duplicate Selective Acknowledgement (DSACK), Eifel and Forward Retransmission Timeout (F RTO). Various network topologies are simulated in a network simulator ns-3 and measure- ments are taken for various path characteristics to see which algorithm works best for the multipath scenario.
M.S. in Electrical Engineering, May 2012
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- Title
- A PARAMETRIC STUDY OF THE THERMAL PERFORMANCE OF DIFFERENT WALL SYSTEMS AT VARIOUS CLIMATE ZONES
- Creator
- Lai, Se Yen
- Date
- 2013, 2013-12
- Description
-
One of the most common energy conservative measures used is designing an air-tight and a well-insulated envelope. While there is an abundance...
Show moreOne of the most common energy conservative measures used is designing an air-tight and a well-insulated envelope. While there is an abundance of high-efficiency building envelope designs in the market which offer low thermal conductivity and high R-values as well as various studies on the thermal performance of various wall constructions, the results were often based on simplified study model and are not incompliance with the current building code. Most studies also focus on only one particular climate zone and one type of wall construction. This research aims to examine the thermal performance of different types of wall construction based on the traditional building envelope design materials in various climate zones based on insulation and air cavity placements on a non-simplified reference model that is used for construction. Study models developed are incompliance with the American Society of Heating, Refrigerating, and Air-Conditioning Engineers [ASHRAE] 90.1-2010 based on U.S. Department of Energy [DOE] Commercial Prototype Building Model. The thermal performance of the wall will be determined using two different methods. The first method will be using Building Energy Modeling [BEM] software where the exterior wall construction will be modified based on DOE reference models where the results for the overall annual energy consumption [AEC] will be compared. AEC results showed small differences between study models which are negligible. The second method is the Total Thermal Constant [TTC] method, where the thermal lag will be compared. The building structures that will be used are a steel-framed structure which represents a medium office and a wood-framed structure which represents a quick service restaurant. TTC results were able to determine the least favorable study model.
M.S. in Civil Engineering, December 2013
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- Title
- A UNIFIED BOUNDARY CONTROL LAW FOR DC-DC CONVERTERS USING A NORMALIZED STATE PLANE
- Creator
- Nie, Yue
- Date
- 2015, 2015-05
- Description
-
This thesis proposes a unified boundary control law for DC-DC converters (Buck, Boost, and Buck-Boost) which improves both the transient and...
Show moreThis thesis proposes a unified boundary control law for DC-DC converters (Buck, Boost, and Buck-Boost) which improves both the transient and steady state response in comparison to boundary control laws using first or second order switching surface. A new set of switching zones on normalized state plane are defined to decide switching behavior every sample period. Additionally, non-ideal operations and a parameter self-adaptive algorithm are proposed and verified in simulation. The parameter self-adaptive algorithm enhances the system robustness and reduces the parameter sensitivity. The transient bandwidth for the load disturbance rejection and command tracking approaches the physical limits of DC-DC converters. Simulation results are presented to illustrate the major benefits of the proposed uni ed boundary control law.
M.S. in Electrical Engineering, May 2015
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- Title
- SUBSTATION PLANNING FOR RURAL DISTRIBUTION SYSTEMS IN AFRICAN COUNTRIES
- Creator
- Soyoye, Oluwadamilola
- Date
- 2016, 2016-12
- Description
-
In sub-Saharan Africa, only 35% of the population is connected to grid electricity [2]. Grid-connected parts face serious transmission and...
Show moreIn sub-Saharan Africa, only 35% of the population is connected to grid electricity [2]. Grid-connected parts face serious transmission and distribution challenges. There is also the challenge of electricity demand being greater than electricity supply. These issues in all levels of the traditional power system – generation, transmission and distribution have led to gross inadequacy of electricity supply. This research focuses on the capital intensive Power Distribution Planning (PDP). Most problems in the distribution system affect the consumer directly. Distribution substation planning, a critical part of the PDP, particularly addresses the issue of overloaded distribution systems. It is not uncommon for substation transformers in some African communities to become damaged because of overloading. The choice of location, sizing, siting and number of substations is determined by considering load distribution, feeder lengths and sizes, and the interruption costs. The research illustrates a framework for substation planning, incorporating possible future load growths over a particular period to forestall unwanted failures in the distribution system. A direct algorithm is used, where the substation capacity is computed manually from the load levels at different points. This algorithm is later combined with the Mixed Integer Linear Programming (MILP) approach solved with the CPLEX solver in MATLAB.
M.S. in Electrical Engineering, December 2016
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- Title
- Tests on enameled wire
- Creator
- Gault, Mark E.
- Date
- 2009, 1911
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/testsonenameledw00gaul
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaf 26
- Title
- MINIMIZING SALMONELLA CONTAMINATION IN SPROUTS BY CONTROLLING THE GERMINATION TEMPERATURE
- Creator
- Zhang, Hanshuai
- Date
- 2013, 2013-12
- Description
-
Since 1990, contaminated sprouts have been linked to at least 46 outbreaks and over 2,500 cases of illness in the US [13]. Unlike other ready...
Show moreSince 1990, contaminated sprouts have been linked to at least 46 outbreaks and over 2,500 cases of illness in the US [13]. Unlike other ready-to-eat produce, sprouts pose a particular concern as the conditions that promote germination of their seeds also facilitate the growth of pathogens [6]. To address sprout’s propensity to microbial contamination, the U.S. Food and Drug Administration (FDA) has recommended that seeds destined for sprout production be disinfected with chemical sanitizers such as 20,000 ppm of calcium hypochlorite, Ca(OCl)2 [29]. However, this disinfectant often cannot completely eliminate pathogen that may be present in seeds [4, 23]; in which case, the surviving bacteria can re-grow to significant numbers during germination and cause severe illness upon consumption [45]. Therefore, maintaining control of the germination conditions to present the proliferation of pathogens is a crucial step in the overall approach to reduce microbial hazards in finished sprouts. This study examines the effects of temperature on the proliferation of Salmonella during germination, and how this temperature effect is influenced by factors such as pathogen load, seed-lot, and the presence or absence of chemical treatment with Ca(OCl)2 was also evaluated. Alfalfa seeds artificially inoculated with ~3 log CFU/g of Salmonella were used as the contaminated seeds. They were mixed at different levels (0.01, 0.1, 1.0, or 10.0% by weight) with 200g of non-contaminated seeds and then were allowed to germinate in glass jars for 3 or 5 days at 10, 20, or 30°C. The same experiment was repeated for the spiking seeds that were treated with 20,000 ppm Ca(ClO)2 for 15 min prior to sprouting. Sprout samples were taken from each jar daily and analyzed for the level of Salmonella ix by either plating on XLD plates or the three-tube most probable number method as described in the FDA BAM. The level of Salmonella increased during sprouting at all three temperatures and reached the highest level at 48h. Sprouting at 10°C yielded the least number of Salmonella when all other factors were controlled. At all spiking levels, or the percentage of seeds contaminated before sprouting, level of Salmonella increased during sprouting, and at 20°C and 30°C, the level of Salmonella reached to a similar level of 5 log CFU/g and 7 log CFU/g respectively. At 1.0% spiking level, the level of Salmonella increased by approximately 1.5, 4.0, and 6.0 log CFU/g in sprouts grown at 10, 20, and 30°C respectively. Difference in the level of microflora background between different seed lots did not appear to affect Salmonella proliferation during sprouting. Treatments with 20,000 ppm free chlorine in some cases lowered the levels of Salmonella to undetectable levels, while in other cases, it caused an approx. 3 log reduction in Salmonella count on seeds. The surviving ones could still proliferate during sprouting although with a delay and a much slower rate, and did not reach the maximal level at 48 h of sprouting. However, Ca(OCl)2 did not prevent the re-growth of Salmonella during germination. In conclusion, these results showed that sprouting temperatures do affect Salmonella proliferations. We recommend lowering the sprouting temperature in conjunction with chemical treatment of prior to sprouting seeds to reduce microbial hazards in sprouts.
M.S. in Food Safety and Technology, December 2013
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- Title
- THE RELATIONSHIPS OF BIOLOGICAL, PSYCHOLOGICAL, AND SOCIAL FACTORS TO PERCEIVED SEIZURE SEVERITY IN INDIVIDUALS WITH TEMPORAL LOBE EPILEPSY
- Creator
- Fong, Wing Man
- Date
- 2012-12-17, 2012-12
- Description
-
Epilepsy is a chronic neurological condition that can cause negative consequences in all areas of life for people with the condition. Research...
Show moreEpilepsy is a chronic neurological condition that can cause negative consequences in all areas of life for people with the condition. Research evidence has led to the goal of treatment to gradually shift from targeting only reducing the frequency of seizures to decreasing individual’s perception of seizure severity. While several studies have suggested that psychological and social factors, in addition to epilepsy-related biological factors, can also impact seizure severity perception, this area has received much less attention in relation to individuals’ perception of seizure severity. Therefore, this study examined individuals’ perception of seizure severity using a biopsychosocial framework which takes into account biological, psychological, and social factors to develop a comprehensive understanding about the perception of seizure severity. 57 individuals from a neurology clinic at a tertiary medical center with a primary diagnosis of localization-related temporal lobe epilepsy participated in this study. They were interviewed for demographic information and were assessed using Quality of Life in Epilepsy-89, Beck Depression Inventory, Stressful Life Events Scale, and Liverpool Seizure Severity Scale. A Multiple regression analysis indicated that the number of antiepileptic drugs, perceived memory function, the number of stressful life events, and social support were all significant predictors of perceived seizure severity. The current findings supported a biopsychosocial approach in understanding the perception of seizure severity among people with epilepsy. Clinical implications of these findings are discussed.
M.S. in Psychology, December 2012
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- Title
- FEASIBILITY OF INDICATOR MICROORGANISMS IN ASSESSING THE EFFICACY OF SANITIZERS IN FRESH PRODUCE WASHING
- Creator
- Zhong, Zeyan
- Date
- 2016, 2016-05
- Description
-
Sanitizers have been widely used in controlling cross-contamination during fresh produce washing processes. It is important to identify...
Show moreSanitizers have been widely used in controlling cross-contamination during fresh produce washing processes. It is important to identify different approaches for monitoring the efficacy of sanitizer washing. In this study, our objective was to determine the feasibility of indicator microorganisms in assessing the efficacy of chlorine and peroxyacetic acid (PAA) in fresh-cut produce washing. In inactivation experiments, the survivals of inoculated indicator microorganisms [total viable count (TVC), Enterobacteriaceae and total coliforms] and E. coli O157:H7 were determined after exposure to different concentrations of chlorine or PAA in water with added organic load (TOC~200 mg/l). In small-scale washing experiments, bacterial transfer from lettuce leaves inoculated with indicators or E. coli O157:H7 to wash water containing chlorine or PAA with/without organic matters was evaluated. In the inactivation study, higher log reduction was observed for Enterobacteriaceae and total coliforms than for E. coli O157:H7 after chlorine treatment at an initial concentration of 30 ppm. In the bacterial transfer study [a inoculated leaf (~5 log CFU) in 30 ml of wash water], without additional organic matter, approximately 3.5 log total CFU of all bacteria groups was transferred into wash water. Less than 1.5 log total CFU were detected for Enterobacteriaceae, total coliforms and E. coli O157:H7 in 1 ppm chlorine washing. With introduced organic matter, similar microbial loads of Enterobacteriaceae, total coliforms and E. coli O157:H7 were detected on washed leaves and in wash water with initial chlorine concentration of 1 ppm; when initial chlorine level increased to 10 ppm, less than 2 log total CFU of Enterobacteriaceae and total coliforms was detected while about 3 log total CFU of E. coli O157:H7 transferred to wash water, suggesting that chlorine at an initial concentration of 10 ppm could not prevent cross-contamination in the presence of organic load. The indicators showed different levels of survival and transfer from E. coli O157:H7 in this study and were unreliable to effectively monitor the behavior of the pathogen during chlorine wash in fresh produce processes. Enterobacteriaceae and total coliforms were more vulnerable to 40 ppm PAA treatment than E. coli O157:H7 in PAA inactivation experiments. No survival, except for TVC, was observed after 80 ppm of PAA inactivation. In the bacterial transfer study, 40 ppm PAA in wash water was found unable to prevent cross-contamination of indicators and E. coli O157:H7 from leaves to water. Further investigation is needed to compare the bacterial transfer levels of E. coli O157:H7 and the indicators at higher PAA levels.
M.S. in Food Safety and Technology, May 2016
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- Title
- APPLICABILITY OF THE INTERVAL ANALYSIS METHOD TO RELIABILITY ASSESSMENT OF STRUCTURES
- Creator
- Taha, Raguez A.
- Date
- 2012-11-26, 2012-12
- Description
-
The scope of this study is focused on the applicability of the interval method to the reliability analysis of structures. The study includes...
Show moreThe scope of this study is focused on the applicability of the interval method to the reliability analysis of structures. The study includes using the traditional probability methods in several applications and comparing the results with the interval analysis. Accordingly, the interval arithmetic rules are applied in several examples and the results are compared with those from the traditional probability theory concepts. Specifically, the procedure for using the interval methods was applied to the development of the probability of failure for a simple structural member; and for a link in a network system. Through three simple examples, the research shows that the interval method offers comparable results with those from the traditional first-order reliability method. The procedure based on the interval method, however, may offer advantages, especially in cases where the uncertainties in various parameters describing the reliability of a system are large. In the presence of large uncertainties, the traditional methods of reliability analysis, based on the first order approximation, may lose their accuracy. In these cases, the interval method may offer a simple method yet with more accurate results.
M.S. in Civil Engineering, December 2012
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