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- Title
- FACTORS AFFECTING THE SANITIZER EFFICACY IN PREVENTING SALMONELLA TRANSFER DURING POSTHARVESTWASHING OF CUT LETTUCE
- Creator
- Zang, Mingxia
- Date
- 2014, 2014-07
- Description
-
This study investigated the spread of Salmonella during postharvest washing of contaminated lettuce and determined the factors that affect the...
Show moreThis study investigated the spread of Salmonella during postharvest washing of contaminated lettuce and determined the factors that affect the efficacy of chlorine in preventing Salmonella cross-contamination. A bench-scale washing system was assembled. It consisted of a 15 gal tank equipped with a submersible pump and various probes to measure wash water properties including pl-l, temperature, chlorine level. oxidation reduction potential (ORP), turbidity, and total organic carbon (TOC) level. Eight grams of cut romaine lettuce inoculated with approximately 7 log CFU/g of Salmonella typhimurium expressing green fluorescent protein were added to 40 L of sterile tap water or spent wash water collected from a commercial produce processing facility together with 800 g of uninoculated lettuce and washed for 2 min. Washing trials were performed at 3°C under different levels of chlorine treatment (0. 5, 10, 20 and 30 ppm of sodium hypochlorite). Small-scale (100 mL) experiments were performed to determine the effects of organic matter (lettuce homogenate) and solids (play sand) on the efficacy of chlorine in wash water. Without chlorine treatment, the spread of Salmonella occurred during lettuce washing in both sterile tap water and in spent industry water. With 5 ppm ofchlorine. although no Salmonella was detected in the wash water, the pathogen was found in the uninoculated lettuce after culture enrichments. When the chlorine level increased to either 10 or 20 ppm of chlorine, no Salmonella was detected in the wash water or the uninoculated lettuce. Similar experiments were performed using the spent industry water. Salmonella transfer occurred at chlorine of 10 or 20 ppm. Transfer was prevented when the chlorine level was raised to 30 ppm. IX Data from the small-scale experiments indicated that the increase in organic contents resulted in a lower level of free chlorine and a greater survival of Salmonella. At 5 ppm of chlorine, the level of Salmonella increased from not detectable « 1 log CFU/ml) to completely unaffected (4.3 ± 0.4 log CFU/ml) when the TOC level increased from 10.6 ± 10.4 to 164.0 ± 21.2 mg/L. Also, the increase in solid contents led to a greater survival of Salmonella even though the free chlorine level remained unchanged. At 0.5 ppm of chlorine, the level ofSalmonella increased from not detectable « 1 log CFU/ml) to completely unaffected (4.2 ± 0.1 log CFU/ml) when the turbidity level increased from 0.7 ± 0.5 to 378.2 ± 53.5 NTU. In summary, the use of sufficient chlorine could prevent Salmonella cross-contamination but the effective chlorine level was affected by the organic load and solid content present in the wash water. Since the chlorine efficacy was the key to preventing cross-contamination and organic load was an important factor affecting the chlorine efficacy, measurements of the organic load was needed to determine the level ofchlorination needed in the wash water. However, current methods for measuring TOC took a few hours to perform. Turbidity measurements which could be done in a minute had been frequently used in the produce industry to determ ine wash water quality. In this study. it was found that a linear correlation could be established between turbidity and TOC suggesting that turbidity could be a good predictor of the organic load in produce wash water.
M.S. in Food Safety and Technology, July 2014
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- Title
- STUDY ON EX POST PRICING
- Creator
- Zhao, Zhechong
- Date
- 2011-05-02, 2011-05
- Description
-
The main objective of this thesis is to study the ex post pricing in electricity market by implementing two new methods (quantity based method...
Show moreThe main objective of this thesis is to study the ex post pricing in electricity market by implementing two new methods (quantity based method and price based method). The quantity based method measures the difference between the actual performance of an individual resource and its bid-based profit-maximizing response to the ex post prices. The price based method measures the different between the ex post price and the supporting price which supports the actual outputs. These two methods are based on a co-optimization market for energy and ancillary service. They are very flexible and can solve the ex post price efficiently and simultaneously.
M.S. in Electrical Engineering, May 2011
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- Title
- COMPARATIVE GENOMICS OF STREPTOCOCCUS SALIVARIUS ATCC 27945 AND 25975; FROM HELPFUL TO HARMFUL?
- Creator
- Soomer-james, Jahna T. A.
- Date
- 2015, 2015-07
- Description
-
Streptococcus salivarius is a commensal bacterium that normally inhabits the oral mucosa. However, preliminary data indicated that the strain...
Show moreStreptococcus salivarius is a commensal bacterium that normally inhabits the oral mucosa. However, preliminary data indicated that the strain ATCC 25975 has acquired parasitic genes from Streptococcus pneumoniae. To investigate the nature of this genetic exchange, the genome of Streptococcus salivarius ATCC 27945 was first sequenced and served as a comparative model to provide insight into the possibility of development of pathogenicity within the salivarius group. Illumina and PacBio sequencing data were used complementarily to generate reliable genomes of the Streptococcus salivarius ATCC 27945 and ATCC 25975 strains. The reads were trimmed, filtered, assembled and annotated using custom Perl scripts and various software. The completed genomes of S. salivarius ATCC 27945 and ATCC 25975 are 2.11 Mbp and 2.20 Mbp long, respectively, with ATCC 25975 featuring an additional plasmid. Comparative genomics with other sequenced salivarius genomes revealed that strain ATCC 27945 was most closely related to strains JIM8777 and NCTC8618, while strain ATCC 25975 was more closely related to strains 57I and CCHSS3. The proteins that were common across the investigated salivarius genomes included housekeeping proteins involved in pathways such as DNA replication, metabolism and DNA repair but the unique protein types and their relative location to each other within the ATCC main chromosomes did not provide conclusive evidence to the identification of the parasitic cassette. However, the plasmid contained in S. salivarius ATCC 25975 showed promising signs of containing these genes of interest. Several genes typically found in S. pneumoniae such as capsular polysaccharide genes and two copies of integrative and conjugative genes were identified in close proximity. The phylogenetic analysis of the two S. salivarius ATCC strains suggested that the proposed genes acquired from S. pneumoniae might have been gained via horizontal gene transfer rather than through sporadic mutations. The plasmid had a 5.1% smaller GC content compared to the other salivarius chromosomes, further suggesting that it was acquired from a distinct organism. Overall, while these results provided useful insights into the nature and location of the parasitic cassette, further investigations will be required to assess the full extent of the genetic shuffling that occurred by horizontal gene transfer in these Streptococcus species.
M.S. in Biology, July 2015
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- Title
- A study of anti-friction lineshaft bearings
- Creator
- Katzinger, Arthur, Alte, Arthur S.
- Date
- 2009, 1916
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/studyofantifrict00katz
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaves 212-220
- Title
- ORGANIZATIONAL FLEXIBILITY IN CONSTRUCTION COMPANIES
- Creator
- Taghizadeh Khamesi, Hossein
- Date
- 2016, 2016-05
- Description
-
Flexibility is a key factor for an organization survival in a changing environment. Considering the cyclical nature of construction demand,...
Show moreFlexibility is a key factor for an organization survival in a changing environment. Considering the cyclical nature of construction demand, organizational flexibility is of special importance in construction company management. Most previous studies tried to categorize the response strategies of construction contractors to business and environmental changes. However, there is gap in the literature about the dynamic effect of organizational flexibility on the growth and competitiveness in construction companies. The objective of this study is to investigate the organizational flexibility of top construction contractors in the U.S. Engineering News-Records (ENR) top 400 contractors lists were used to collect data for the 52-year period 1963-2015. Using the collected data, several analyses were performed to find the relationship between organizational flexibility and competitive success. This attempt did not indicate a distinct relationship between organizational flexibility and competitiveness. It was found however that organizational flexibility is affected by change in the economy and that it was linked to company expansion/contraction. It is concluded that organizational flexibility is an essential advantage for construction contractors. Those contractors that are consistently ranked in the top 400 contractors list respond well to economic changes by expanding and contracting. On the other hand, different size contractors respond to changes in the economy differently, based on their resources and the nature of their work. In addition, this study concluded that those contractors that seek high growth rates face more fluctuations in their growth path and need more flexibility in response to them.
M.S. in Civil Engineering, May 2016
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- Title
- Buffalo Food Path
- Creator
- Huttel, Anna
- Date
- 2010-07-29
- Title
- The study and design of spray nozzles as applied to the De La Vergne oil engine
- Creator
- Harman, William E. S, Ward, Fred L
- Date
- 2009, 1915
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/studydesignofspr00harm
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaf 2
- Title
- UNDERSTANDING UNCERTAINTIES IN RESOLVED PHOTON STRUCTURE
- Creator
- Zhan, Hengrui
- Date
- 2017, 2017-07
- Description
-
The construction of a photon collider has been urged, in order to study the properties of the Higgs boson and electroweak symmetry breaking....
Show moreThe construction of a photon collider has been urged, in order to study the properties of the Higgs boson and electroweak symmetry breaking. It would also provide unique possibilities for measurement of fusion to probe the hadronic structure of the photon. One scheme of design for the photon collider is a linear collider. A study shows that resolved photons contribute about 15% of the cross section to Higgs production with a mass of 120 GeV, but estimates of the resolved photon structure have so far varied greatly. Therefore, resolved photon structure is important to measure. This thesis focuses on the determination of the uncertainties of the cross section of bb production for better understanding of resolved photon structure. The principles of a photon collider are reviewed. In this thesis, the simulation tools for the simulation of the cross section of ! bb collision are developed. After that, the method for determination of the uncertainties of cross section is described. A new set of PDFs to explore these uncertainties is produced. The result of the simulation of the cross section and the calculation for the uncertainties of the cross section is presented and discussed in detailed.
M.S. in Physics, July 2017
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- Title
- DISCONTINUOUS IN THE NI-CO-AL PRECIPITATION ALLOY SYSTEM
- Creator
- Liu, Tian
- Date
- 2014, 2014-05
- Description
-
The synthesis of nanoplates of 0 by use of discontinuous precipitation was investigated in the Ni-Co-Al alloy system. A series of experiments,...
Show moreThe synthesis of nanoplates of 0 by use of discontinuous precipitation was investigated in the Ni-Co-Al alloy system. A series of experiments, such as heat treatment, cold rolling, and electrolytic etching, have been performed to develop the desired microstructure. Nanostructured materials have great potential in a number of applications, such as catalysis, light weight structural materials, thermal management and pollution reduction. Kinetic information of the Ni-Co-Al alloy was obtained through measuring the optical micrographs of samples aged at di erent temperatures. The morphology of the nanostructure of the Ni-Co-Al alloy was investigated using scanning electron microscopy (SEM). The mechanical property (hardness) of the Ni-Co-Al alloy was obtained in di erent conditions as well. The Ni-Co-Al alloys were recrystallized in di erent ways. The texture of the alloys were determined using electron backscattered di raction (EBSD). After analyzing those experimental results, we nd that the discontinuous precipitation goes to completion in the Ni-Co-Al alloy. The discontinuous precipitates present a lamellar structure. The size of plates is similar with the spacing between plates and achieves a nanoscale architecture. The TTT curve of the Ni-Co-Al alloy with a composition of 43 at.% Ni, 48 at.% Co and 9 at.% Al provides abundant kinetic information. Further work is needed to produce a strong cube texture ((100) planes parallel to the foil surface).
M.S. in Materials Engineering, May 2014
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- Title
- Redefining the Urban Lifestyle, West Englewood, Chicago, IL
- Creator
- Haberkost, Jesse
- Date
- 2010-07-29
- Title
- BIODESULFURIZATION IMPROVEMENT OF A SYMBIOTIC PAENIBACILLUS CULTURE UTILIZING VITREOSCILLA HEMOGLOBIN
- Creator
- Liu, Benjamin Kwan
- Date
- 2015, 2015-05
- Description
-
Biodesulfurization (BDS) of petroleum has been investigated as an alternative method to conventional chemical desulfurization for many years....
Show moreBiodesulfurization (BDS) of petroleum has been investigated as an alternative method to conventional chemical desulfurization for many years. Despite its potential to be an environmentally benign method, it has not been developed sufficiently to be useful in real world applications. This is due to its low efficiency and the necessity for it to work at temperatures high enough to lower the viscosity of petroleum so that mixing can be achieved. This study places the spotlight on two strains of Paenibacillus isolated in our laboratory that, together, possess biodesulfurization ability at moderately high temperatures and attempts to enhance biodesulfurization by expression of Vitreoscilla hemoglobin (VHb) in the Paenibacillus strains. The effects of expression of the VHb gene (vgb) on growth and desulfurizing activity was examined in a symbiotic system between the Paenibacillus strains 32O-Y and 32O-W. Of the two, 32O-Y is the one with the ability to metabolize dibenzothiophene (DBT), a common compound in petroleum that contains organic sulfur, while 32O-W enhances this ability, forming a symbiotic relationship between the two. The transformant of 32O-Y bearing vgb cloned into the shuttle vector pNW33N had been previously constructed in our laboratory. Presence of pNW33N-vgb was verified in one strain of 32O-Y through isolation of DNA, PCR, and gel electrophoresis. Mixtures of 32O-Y/32O-W or 32O-Y[pNW33N-vgb]/32O-W were cultured in minimal medium (CDM) with DBT as the sole sulfur source and subjected to multiple trials of growth and assay of DBT metabolism at varying temperatures. At 45 ˚C there was a substantial increase in both growth and DBT metabolizing coincident with VHb expression, whereas at lower (37 ˚C) and higher (50 ˚C) temperatures, VHb expression had little to no effect on either parameter. For both growth and DBT metabolism tested at 37 ˚C, 45 ˚C and 50 ˚C the highest absolute levels were seen at 37 ˚C, and the lowest at 45 ˚C.
M.S. in Biology, May 2015
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- Title
- HYPOTHESIS TESTING FOR STOCHASTIC PDES DRIVEN BY ADDITIVE NOISE
- Creator
- Xu, Liaosha
- Date
- 2013, 2013-12
- Description
-
We study hypothesis testing problem for the drift/viscosity coefficient for stochastic fractional heat equation driven by additive space-time...
Show moreWe study hypothesis testing problem for the drift/viscosity coefficient for stochastic fractional heat equation driven by additive space-time white noise colored in space. Since it is the first attempt to deal with hypothesis testing in SPDEs, we assume that the first N Fourier modes of the solution are observed continuously over time interval [0, T], similar methodology could be developed later for discrete sampling. The highlight of this article lies in the notion of “asymptotically the most powerful test” we introduce, which is a brand new idea for hypothesis testing not only in stochastic PDEs but in general stochastic processes. This conception provides a definite criterion how we compare the convergence rates of errors of two tests and how we maximize this convergence rate in a given rejection class when T or N is near infinity. And also we will give some equally important results for controlling the errors with finite T and N. We will build up asymptotic rejection class and find explicit forms of “the most powerful test” in two asymptotic regimes: large time asymptotics T →∞, and increasing number of Fourier modes N → ∞. The proposed statistics are derived based on Maximum Likelihood Ratio. We first consider a simple hypothesis testing, for which we exploit the key technic, by which we continue considering for more general issues. Over the course of proving the main results, we obtain a series of technical results on the asymptotic behaviors of the probabilities related to likelihood ratio, which are also, in some sense, of high value for study in probability theory. In particular, we find the cumulant generating function of the log-likelihood ratio, we obtain some sharp large deviation type results for both T → ∞ and N → ∞, and develop some useful strategies in probability convergence for studying asymptotic properties of the power of the likelihood ratio type tests.
M.S. in Applied Mathematics, December 2013
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- Title
- Hybrid Living Space in the Context of Balat, Istanbul: Unal_Nezihe_Final Presantation
- Creator
- Unal, Nezihe Merve
- Date
- 2010-05
- Publisher
- Description
-
- Title
- A study of the effect of momentary external fields on the retentivity of the permanent magnets of recording wattmeters
- Creator
- Simmons, Leslie E.
- Date
- 2009, 1909
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/studyofeffectofm00simm
Thesis (B.S.)--Armour Institute of Technology
- Title
- DETECTING A SPIT CALLER USING UN-SUPERVISED MACHINE LEARNING
- Creator
- Opara, Stanley
- Date
- 2013-05-02, 2013-05
- Description
-
Spam over Internet Telephony (SPIT) is a form of un-solicited communication whereby an attacker sends automatically pre-recorded phone calls...
Show moreSpam over Internet Telephony (SPIT) is a form of un-solicited communication whereby an attacker sends automatically pre-recorded phone calls to several subscribers for purposes such as advertisements of product and services etc. In the near future, SPIT is expected to become a threat inhibiting the delivery of voice services over INTERNET because of its technical and economic characteristics. In this report, we purpose a detection mechanism to identify SPIT callers. This mechanism transforms the problem of identification of SPIT callers to a data clustering one by mapping callers to data points based on some characteristics. These characteristics (features) are gathered based on signaling characteristics, caller reputation and call metrics. These features include modified SymRank, termination coefficient, strong tie coefficient and average call duration. These features distinguish between a normal caller and SPIT caller but cannot stand alone as shown in the Results section. The data clustering was done by an un-supervised learning algorithm known as k-means which clusters closely related data points. To test our model, we simulated a testbed since we could not obtain real traffic. The testbed was generated in java, while the actual clustering algorithms were written Octave. The results gathered clearly showcased the high efficacy of our model, as it had accuracy (>95%) in all tests. After comparing our model with other models proposed by fellow researchers, we realized that our model either surpassed or was comparable to the other models considered.
M.S. in Electrical Engineering, May 2013
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- Title
- The variation of iron loss in transformers with shape of applied emf wave
- Creator
- Strong, Arthur Poole
- Date
- 2009, 1909
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/variationofironl00stro
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaf 1
- Title
- PARAMETRIC COST ESTIMATION MODEL OF INTEGRATED REACTOR VESSEL UNDER MODULAR CONSTRUCTION WITHIN A FACTORY ENVIRONMENT
- Creator
- Chen, Xuan
- Date
- 2013, 2013-12
- Description
-
High initial cost is one of the major barriers for the nuclear power industry. Small modular reactors (SMR) may be a solution to this problem...
Show moreHigh initial cost is one of the major barriers for the nuclear power industry. Small modular reactors (SMR) may be a solution to this problem because they have a much smaller financial barrier. In this thesis, parametric cost estimation modeling studies have been performed for the SMR integrated reactor vessel (IRV) under a factory environment. Based on different prior fabrication experiences, three scenarios have been studied, and the corresponding possible manufacturing costs of the entire IRV and its subcomponents have been estimated. To explore the cost allocation, the total cost has been divided into five cost contributors: labor, material, tooling labor, tooling replacement, and other. The results have been analyzed and discussed.
M.S. in in Mechanical, Material and Aerospace Engineering, December 2013
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- Title
- Nibakure Children's Village School: Nibakure Childrens Village School
- Creator
- May, Bryan
- Date
- 2010-07-13
- Title
- MODELING AND SIMULATION OF DYNAMIC VOLTAGE CONTROLS AND PROTECTION IN 3 PHASES TRANSIENT STABILITY ANALYSIS
- Creator
- Zhang, Qiaoyu
- Date
- 2016, 2016-12
- Description
-
The main object of this research is to build up a comprehensive 3-phases transient stability simulator(TS3ph) and use it to analyze the...
Show moreThe main object of this research is to build up a comprehensive 3-phases transient stability simulator(TS3ph) and use it to analyze the transient stability with dynamic voltage control and protection. Detailed exciter models, SVC model and protection model are needed in this research. We have implemented detailed exciter model. We chose several exciter models which are frequently used in power system to built. These exciters can control generator terminal voltage by changing current and voltage to generator field winding. It is critical for improving the dynamic voltage performance in power system. We also built up detailed SVC model. The SVC is an important device for dynamic voltage control. It is a power electronics-based equipment containing both reactors and capacitor banks which have the capability of dynamic voltage and reactive power control. When doing the dynamic voltage control simulation, it is meaningful to have a detailed SVC model in the transient simulator. The another mission of this research is to study the protection of power system with unbalance fault or unbalance network using 3-Phase Transient Stability Simulator. In order to obtain the relay operation, we need to set up the interface between protection simulator Electrocon CAPE and transient simulator TS3ph. As unbalance fault sometimes can cause serious voltage problem during the transient, simulating the unbalance fault with realistic relay operation is important for transient stability analysis.
M.S. in Electrical Engineering, December 2016
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- Title
- Eat Local Cleveland
- Creator
- Blewitt, Matthew
- Date
- 2010-07-29