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(81 - 100 of 1,633)
Pages
- Title
- SUSTAINABLE, CONTROLLED, REACTION SYNTHESIS OF METALLIC WIRES AND STRIPS
- Creator
- Chen, Xin
- Date
- 2014, 2014-05
- Description
-
The main purpose of this work is to investigate bi and tri-metallic metal com- binations as initiators which require an ability to have a self...
Show moreThe main purpose of this work is to investigate bi and tri-metallic metal com- binations as initiators which require an ability to have a self-sustaining exothermic reaction. Through the reaction, the initiator should achieve a temperature in excess of 500 C when in contact with a thermally conducting surface. Also the initiator must be in the form of a exible wire or strip of the order of one millimeter radius. There are four phases in my MS research project. First was identifying the potential candidate compounds for exothermic reaction. During this phase, I wrote a program using Mathematicar (Appendix A) to calculate the adiabatic temperature resulting from the reaction of di erent binary or ternary elemental combinations. The calculation took into account the speci c heats and any enthalpies of transformation occurring between room temperature and the adiabatic temperature. Based on the results of this program several suitable compositions were selected from three hun- dred candidates. The second phase was determining a methodology to manufacture selfCpropagating thin strips or wires. We attempted several methods including plate rolling, wire twisting, mechanical coating, chemical coating, and powder metallurgy. We successfully obtained self-propagating thin metal strips and wires using powder metallurgy methods. In the third phase, a transparent reaction box was constructed in order to provide a protective atmosphere (Ar gas) and connect to a data acqui- sition system to obtain the reaction temperature, initiation temperature and video materials of reactions. In the last phase, the reacted samples were characterized using Scanning Electron Microscope (SEM), Backscattered Electron detector (BSE), X-ray Di raction (XRD), Di erential scanning calorimeter (DSC), etc.
M.S. in Mechanical, Materials, and Aerospace Engineering, May 2014
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- Title
- Greenweb
- Creator
- Thomas, Boerman
- Date
- 2010-07-29
- Title
- CONSTITUTIVE BEHAVIOR AND MODELING OF AL-CU ALLOY SYSTEMS
- Creator
- Turkkan, Omer Anil
- Date
- 2013-05-07, 2013-05
- Description
-
High speed deformation events such as caused by projectile penetration, fragment impact and shock/blast loading are of great importance in...
Show moreHigh speed deformation events such as caused by projectile penetration, fragment impact and shock/blast loading are of great importance in designing materials and structures for army applications. In these events, materials are subjected to large strains, high strain rates and rapid increase in temperature due to thermoplastic heating. In such severe conditions, overall performance is determined by the evolution of flow stress, failure initiation and propagation, and commonly in the form of adiabatic shear banding. Some of 2XXX series aluminum-copper (Al-Cu) alloys are recognized for their decent ballistic properties, and therefore they have been used as an armor material for lightweight U.S. Army vehicles. Most recently, an Al-Cu-Mg-Mn-Ag alloy labeled as Al 2139-T8 has been developed and is evaluated by the U.S. Army Research Labs. because of its better ballistic properties and higher strength than its predecessors. The underlying microstructure is believed to be the key element for this superior performance. The goal of this study is to explore the effect of composition and microstructural features on overall dynamic material behavior by examining mechanical and deformation behavior of different Al-Cu material systems. Starting from the pure single crystal and polycrystalline Al structures, and adding a different element to chemical composition in each step (i.e., Cu, Mg, Mn, Ag), mechanical response of these different systems has been investigated. For all alloy systems with the exception of single crystal Al, mechanical tests have been performed at room and elevated temperatures covering quasi-static ( to ) and dynamic ( to strain rate regimes. xiv Shear-compression specimens promoting localized shear deformation have been used to explore tendency of each one of these materials to failure by adiabatic shear banding. In addition to phenomenological Johnson-Cook Model (JCM), physics based Zerrilli-Armstrong and Mechanical Threshold Models have been studied to model the constitutive response of Al-Cu alloys over a wide range of strain rates and temperatures.. An improved ZA model has been developed to better capture the trends in experimental data.
M.S. in MECHANICAL, MATERIALS, AND AEROSPACE ENGINEERING, May 2013
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- Title
- Wagner single phase induction motor
- Creator
- Ash, H. J., Croskey, Philip
- Date
- 2009, 1905
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/wagnersinglephas00ashh
Thesis (B.S.)--Armour Institute of Technology
- Title
- Biophilic Calumet
- Creator
- Meder, Robert
- Date
- 2010-07-29
- Title
- SITE-DIRECTED MUTAGENESIS STUDY OF VITREOSCILLA HEMOGLOBIN-THE ROLE OF TYROSINE (B10) AND PROLINE (E8) IN THE STRUCTURE OF THE LIGAND-BINDING SITE
- Creator
- Zhang, Yifan
- Date
- 2015, 2015-05
- Description
-
Vitreoscilla is a genus of Gram-negative aerobic bacterium which has the capability to synthesis a soluble, homodimertic hemoglobin,...
Show moreVitreoscilla is a genus of Gram-negative aerobic bacterium which has the capability to synthesis a soluble, homodimertic hemoglobin, Vitreoscilla hemoglobin (VHb). The Vitreoscilla hemoglobin was the first bacterial hemoglobin discovered, and has a wide range of biological and biotechnological applications. The distal site is one of the hot spots in VHb studies because of its unique structure. The Tyrosine residue at B10 and its hydrogen bonded Proline at E8 were considered as the ligand binding functional sites in distal space of VHb according to the previous study. In this study, two single mutated and one double mutated Vitreoscilla hemoglobin at position B10 and E8 were constructed and purified. In the two single mutants, the Tyr at B10 and the Pro at E8 were mutated to Ala. In the double mutant, both of the sites were mutated to Ala. The CO di↵erence spectrum data of the mutants indicate that the ligand binding ability of the Vitreoscilla hemoglobin was not neutralized by the mutations at ProE8 and TyrB10. Circular dichroism spectrum data of the mutants is similar to the wild type Vitreoscilla hemoglobin, which means the globin secondary structure is conserved. However the micro-environment in the distal sites is changed: the IR spectrum of the carbonyl stretch bond red-shifted in the CO bound VHb double mutant. A molecular dynamic simulation was introduced in the study to o↵er some guidance for future research plans. The simulation results showed that the B10 and E8 residue mutated to Ala might reduce the flexibility of the D-region, because of the more completed C and E helix. The volume of cavity where the heme group inserts changes significantly in various mutant models, which may provide a rough explanation of the change in carbonyl stretch bond IR spectrum. Additionally, an interesting conformation of Gln E7 was found in the simulation of double mutant model.
M.S. in Biology, May 2015
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- Title
- MIN- AREA RETIMING UNDER WIRE-DELAY MODEL
- Creator
- Luo, Tianchen
- Date
- 2011-05-09, 2011-05
- Description
-
Retiming is a powerful optimization technique for synchronize sequential circuits that relocates delay unit without changing the circuit’s...
Show moreRetiming is a powerful optimization technique for synchronize sequential circuits that relocates delay unit without changing the circuit’s input-output functionality. Wire delay is significant and can no longer be ignored in deep sub-micrometer technologies. Existing algorithms solve the problem of min-area and min-period either optimal or heuristically without taking wire delay into consideration. However, those techniques cannot be applied directly to circuit with wire delay. Recent work solved the min-period problem under wire delay model. This paper proposes an algorithm that solves the problem of min-area wire retiming under fixed clock period optimally and efficiently.
M.S. in Electrical and Computer Engineering, May 2011
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- Title
- INCORPORATING INVARIANCE INTO SUPPORT VECTOR MACHINE FOR DETECTION OF MICROCALCIFICATIONS
- Creator
- Yang, Yan
- Date
- 2011-11-16, 2011-12
- Description
-
In this thesis, we explore methods for incorporating invariance into a support vector machine (SVM) classifier in detection of clustered...
Show moreIn this thesis, we explore methods for incorporating invariance into a support vector machine (SVM) classifier in detection of clustered microcalcifications (MC) in mammogram images. Unlike standard SVM, both virtual SVM and tangent vector SVM can include prior information into a trained model. We formulate MC detection as a two-class classification problem and apply these three types of SVM classifiers to this problem. The issue of dimensional reduction is considered in the tangent vector SVM, which has influence on the computational cost and complexity of the algorithm. We test and compare their performance on a set of 200 clinical mammogram images which contain a total of 5,115 MCs. In the experiments these classifiers are optimized with a training procedure for model selection. We evaluate the detection performance using both receiver operating characteristic (ROC) curves and free-response operating characteristic (FROC) curves. The results show that both virtual SVM and tangent vector SVM can outperform the standard SVM. The use of dimensional reduction in tangent vector SVM can effectively reduce the computational cost.
M.S. in Electrical Engineering, December 2011
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- Title
- Tests on the gravity cell
- Creator
- Evans, P. W., Linderberg, W. A.
- Date
- 2009, 1912
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/testsongravityce00evan
Thesis (B.S.)--Armour Institute of Technology
- Title
- NATURAL AGING EFFECT ON DOUBLE AGED ALUMINUM ALLOY AA7075
- Creator
- Kara, Baris
- Date
- 2012-04-27, 2012-05
- Description
-
The effect of natural aging (NA) on mechanical properties in double aged aluminum alloys, AA7075, was studied by means of hardness tests,...
Show moreThe effect of natural aging (NA) on mechanical properties in double aged aluminum alloys, AA7075, was studied by means of hardness tests, tensile tests and stress corrosion cracking (SCC) tests. Natural aging can strengthen AA7075 alloys after solution heat treatment, and reaching the stable condition can take years for the alloy. Double aging (DA) is very beneficial method in terms of energy savings and productivity because this method provides the peak hardness in a much shorter time compared to single aging, and DA treatment produces hardness, yield stress and tensile stress which are comparable with those produced by SA. In this study, the alloys were naturally aged for different times before double aging treatment, and the relationship between double aging treatment and natural aging treatment was observed. The results show that different natural aging times do not significantly affect the final mechanical properties of double aged alloys. Consequently, the loading time to aging furnace after solution heat treatment does not play an important role in the double aging treatment of AA7075 alloys.
M.S. in Materials Science and Engineering, May 2012
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- Title
- FLEXIBLE COGNITIVE STYLE MODERATES THE RELATIONSHIP BETWEEN RUMINATION AND AFFECT
- Creator
- Smetter, Joseph B.
- Date
- 2014, 2014-12
- Description
-
Prospective and longitudinal studies have demonstrated that rumination has a negative effect on mood and depression outcomes. The present...
Show moreProspective and longitudinal studies have demonstrated that rumination has a negative effect on mood and depression outcomes. The present study examined whether the type of flexible cognitive style needed to reevaluate maladaptive thoughts and interpretations (i.e. cognitive flexibility) acts as a buffer against the negative relationship between rumination and affect. Participants (N = 100) completed anonymous online surveys containing two measures of cognitive flexibility, including the Beck Cognitive Insight Scale (BCIS; Beck et al., 2008) and the Cognitive Flexibility Inventory (CFI; Dennis & Vander Wal, 2010), as well as measures of depressive rumination and trait affect. Multiple regression-based moderation analyses showed that the tendency to be more objective, reflective, and open to feedback moderated the relationship between rumination and positive affect (PA), such that the negative relationship between rumination and PA was attenuated for individuals who were more self-reflective. We discuss the implications of this buffering effect for theories of rumination and research on protective factors, as well as its relevance to psychotherapy. A comparison of the cognitive flexibility questionnaires revealed differences in how flexible reinterpretation is measured and identified selective relationships to positive and negative affect. Based on these findings, we provide recommendations for future research on cognitive styles that promote flexible reinterpretation.
M.S. in Psychology, December 2014
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- Title
- SYSTEM DESIGN AND HARDWARE VERIFICATION OF A S-MFCW RADAR
- Creator
- Nadkarni, Satwik
- Date
- 2014, 2014-05
- Description
-
Low cost imaging radar systems are an emerging field today with very useful applications in automotive, healthcare and entertainment...
Show moreLow cost imaging radar systems are an emerging field today with very useful applications in automotive, healthcare and entertainment industries. The aim is to realize an effective and reliable radar system that has a good resolution and at the same time a low cost and complexity. The S-MFCW radar technique has been shown to achieve comparable resolution with the FMCW technique while at the same time maintaining the advantages of reduced hardware complexity and low power consumption. This makes the S-MFCW technique very useful in low cost and low complexity user end devices. The aim of this thesis is to develop a S-MFCW radar system that is capable of measuring distance of an object as well as its velocity. The radar system was implemented using two different approaches – a modular approach and an integrated approach. Both the implementations were tested and the results were found to be in line with expectations from previous research work.
M.S. in Electrical Engineering, May 2014
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- Title
- Mobile Maritime Center
- Creator
- Hamill, Kristina
- Date
- 2010-07-29
- Title
- THE CORRELATION BETWEEN FATIGUE PROPERTY AND PORE MORPHOLOGY OF POWDER METALLURGY TI6AL4V
- Creator
- Yan, Yingjie
- Date
- 2012-12-12, 2012-12
- Description
-
The microstructure and fatigue properties of sintered Ti-6Al-4V were investi- gated as a function of sintered density and pore morphology. A...
Show moreThe microstructure and fatigue properties of sintered Ti-6Al-4V were investi- gated as a function of sintered density and pore morphology. A quantitative analysis of microstructure was conducted to correlate with tensile and fatigue properties to understand the in uence of sintering density and pore morphology. Low cycle fatigue (LCF) using constant strain control was conducted at room temperature, R=-1 and sine waveform. High cycle fatigue (HCF) using constant stress control was conducted at room temperature, R=0.1 and sine waveform. It was found that there was no signi cant di erence in tensile strength but the fatigue endurance limit was increased by 20% when the sintering density was increased from 95% to 99%. Moreover, fatigue endurance limit was increased when the shape factor increased among three di er- ent sintering conditions(1010 -60min-690MPa, 1130 -90min-410MPa, 1250 -30min- 550MPa). Fracture surface analysis indicated that the fatigue crack initiated from the cluster of pore either at surface or at the sub-surface. The implication of pore morphology and porosity on mechanical behaviour and fatigue fracture of P/M Ti- 6Al-4V were discussed. It was estimated that the shape factor was 0.05 for A-50 and 0.07 for A-100, respectively. A polynomial relationship was found between the fatigue endurance limit and shape factor among three sintering con gurations. It was found that the PM parts with a higher shape factor had a higher fatigue endurance limit.
M.S. in Materials Science and Engineering, December 2012
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- Title
- Hostile Spaces and Hostel Spaces: Re-Visioning Highway Infrastructure: Kevin_Smith Final Thesis Board 02-0f-03
- Creator
- Smith, Kevin
- Date
- 2010-07-30
- Title
- DEVELOPMENT AND VALIDATION OF A HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD FOR SIMULTANEOUS DETERMINATION OF VITAMINS A AND D IN FLUID MILK PRODUCTS
- Creator
- Li, Wenjing
- Date
- 2013, 2013-12
- Description
-
Measurement of fortification levels for vitamins A and D in fluid milk products is required by the U.S. Food and Drug Administration (FDA)...
Show moreMeasurement of fortification levels for vitamins A and D in fluid milk products is required by the U.S. Food and Drug Administration (FDA) according to Pasteurized Milk Ordinance. In the current study, a high performance liquid chromatographic (HPLC) method was developed for simultaneous determination of retinyl palmitate (vitamin A) and cholecalciferol (vitamin D3) in fortified milk, which will enhance the efficiency of routine monitoring of fortification for processors as well as laboratories. Saponification conditions and extraction solution compositions were studies for best recovery and simplification of the extraction procedures. Saponification conditions studied included temperature (20, 40 and 60℃), time (0.5 to 16 hour) and concentration of KOH (20, 30, 40 and 50%). The variables studied for extraction included solvent compositions (hexane, diethyl ether, ethyl acetate and dichloromethane) and corresponding polarities (0.1, 0.25, 0.5 and 0.75), and number of extractions (once, twice and three times). Freezing and centrifuging steps were also investigated to compare to SPE clean-up, as an alternative method to clean-up before injection. The optimum parameters found were: saponification conditions at 60℃ for 2 hours with 40% (w/v) KOH liquid-liquid extraction with hexane: diethyl ether (80:20, v:v). Vitamins A and D3 were quantitated using an HPLC system with fluorescence detector (FLD) and diode array detector (DAD) respectively within the same injection. Spike recoveries from three different fat levels (skim, 2% and whole) of commercial pasteurized milk samples were in the range of 94 to 110% for both vitamins A and D3 at three spike concentration levels. In addition, at National Institute of Standards and Technology (NIST) Standard Reference Material (SRM 1849a) was used xii for method accuracy evaluation. With eight replicates, the average vitamin A (expressed as retinol equivalents) concentration was 7.52 ± 0.23 μg/g, vitamin D3 concentration was 0.114 ± 0.0062 μg/g, an excellent agreement with the certified value of 7.68 ± 0.23 μg/g for vitamin A and 0.11 ± 0.017 μg/g for vitamin D3. In summary, an HPLC method for simultaneous determination of vitamins A and D3 in fluid milk products has been developed. The method showed high efficiency and accuracy of analysis during a single laboratory validation.
M.S. in Food Safety and Technology, December 2013
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- Title
- OPTIMAL MATERIAL SELECTION MODEL FOR LEED CERTIFICATION USING GENETIC ALGORITHMS
- Creator
- Kim, Taehyoung
- Date
- 2012-12-16, 2012-12
- Description
-
Material selection is an important part of building design because it has great impact on the environment, as buildings during/after...
Show moreMaterial selection is an important part of building design because it has great impact on the environment, as buildings during/after construction are responsible for a large portion of carbon emissions and use many resources and considerable energy. Selecting green materials is an emergent issue in both design firms and construction companies. Green building certification such as LEED systems originated from the desire to improve environmental, economic, financial, and social benefits. The current approach to material selection for sustainability is based only on the designer’s past experiences. An arbitrary approach based on subjective opinions causes unnecessary expense, longer construction duration, and failure to meet desired environmental goals. In order to help decision-makers with the selection of the right materials, this study proposes a model that uses Genetic Algorithms in MATLAB and that optimizes the desired points in LEED Certification within budget constraints. This model can be applied to any project that is pursuing LEED Certification. If the user specifies the desired LEED points, the system recommends the least expensive combination of materials extracted from a database containing detailed information about a large member of materials. The modified model uses multi-objective genetic algorithms to establish trade-off between budget constraints and LEED points. The proposed system is expected to be a useful tool for inexperienced designers and a valuable guideline for designers with extensive experience.
M.S. in Civil Engineering, December 2012
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- Title
- Test of a delco lighting plant
- Creator
- Porges, Edward D., Given, Louis E
- Date
- 2009, 1917
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/testofdelcolight00porg
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaf 88
- Title
- Study of the production of resorcin
- Creator
- Cable, D. E., Prest, J. I.
- Date
- 2009, 1918
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/studyofproductio00cabl
Thesis (B.S.)--Armour Institute of Technology
- Title
- INTEGRATION OF TANGENTIAL FLOW FILTRATION AND IMMUNOMAGNETIC SEPARATION FOR RAPID DETECTION OF ESCHERICHIA COLI 0157:H7 IN PRODUCE WASH WATER
- Creator
- Ren, Yan
- Date
- 2011-12-12, 2011-12
- Description
-
Escherichia coli O157:H7 is one of the most commonly reported pathogens associated with microbial contamination of leafy greens. Since washing...
Show moreEscherichia coli O157:H7 is one of the most commonly reported pathogens associated with microbial contamination of leafy greens. Since washing is a major postharvest processing step, microbial testing of spent wash water has been suggested as a good marker to determine the contamination status of the products. In this study, the efficiency of four commercial rapid methods (BAX®, IQ-Check, Reveal® and mini-VIDAS®) for detection of E.coli O157:H7 in lettuce wash water was evaluated in comparison with the FDA BAM method. The improvement of the detection sensitivity of these tests by immunomagnetic separation (IMS) technology and sample pre-concentration by Tangential Flow Filtration (TFF) was determined. Twenty-five ml of lab prepared lettuce wash water samples were spiked with 0, 1, 10, 100 CFU of E.coli O157:H7, and subjected to enrichment protocols recommended by each of the methods. The presence of E.coli O157:H7 in the enriched samples were then assayed by the test kits, either directly or after IMS (IMS-Pathatrix ™ or IMS-Dynabeads™) treatments. All four test kits and BAM were able to detect E.coli O157:H7 at levels as low as 1 CFU/25ml of wash water. IMS treatments did not lead to further improvement in detection sensitivity. Experiments were also performed to determine the feasibility of incorporating IMS and sample pre-concentration to achieve culture-free detection. Fifty ml of wash water samples were inoculated with E.coli O157:H7 at levels of 0 to 107 CFU and analyzed by the test kits either directly or after IMS-Pathatrix™ treatment. Additionally, 10 L of wash water either prepared in the lab or collected from a commercial fresh-cut processing facility were inoculated with 0 – 106 CFU of the pathogen and subjected to TFF concentration prior to IMS or test kit analyses. IQ-Check showed the highest sensitivity with a detection limit as low as 103 CFU/50ml, and, with IMS, achieved a sensitivity of 100 CFU/50ml. Combining TFF concentration and IMS, 10 L of lab prepared wash water can be tested with IQ-Check and achieve a detection limit of approx. 100 CFU/10 L within 6 hours. For 10L of industry spent wash water, IQ-check also showed the highest sensitivity but the results lacked consistency and required additional evaluations.
M.S. in Food Safety and Technology, December 2011
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