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Pages
- Title
- EBSD CHARACTERIZATION OF LOW TEMPERATURE DEFORMATION MECHANISMS IN MODERN ALLOYS
- Creator
- Kozmel, Thomas S Ii
- Date
- 2015, 2015-05
- Description
-
For structural applications, grain re nement has been shown to enhance mechanical properties such as strength, fatigue resistance, and...
Show moreFor structural applications, grain re nement has been shown to enhance mechanical properties such as strength, fatigue resistance, and fracture toughness. Through control of the thermo-mechanical processing parameters, dynamic recrystallization mechanisms were used to produce microstructures consisting of sub-micron grains in 9310 steel, 4140 steel, and Ti-6Al-4V. In both 9310 and 4140 steel, the distribution of carbides throughout the microstructure a ected the ability of the material to dynamically recrystallize and determined the size of the dynamically recrystallized grains. Processing the materials at lower temperatures and higher strain rates resulted in ner dynamically recrystallized grains. Microstructural process models that can be used to estimate the resulting microstructure based on the processing parameters were developed for both 9310 and 4140 steel. Heat treatment studies performed on 9310 steel showed that the sub-micron grain size obtained during deformation could not be retained due to the low equilibrium volume fraction of carbides. Commercially available aluminum alloys were investigated to explain their high strain rate deformation behavior. Alloys such as 2139, 2519, 5083, and 7039 exhibit strain softening after an ultimate strength is reached, followed by a rapid degradation of mechanical properties after a critical strain level has been reached. Microstructural analysis showed that the formation of shear bands typically preceded this rapid degradation in properties. Shear band boundary misorientations increased as a function of equivalent strain in all cases. Precipitation behavior was found to greatly in uence the microstructural response of the alloys. Additionally, precipitation strengthened alloys were found to exhibit similar ow stress behavior, whereas solid solution strengthened alloys exhibited lower ow stresses but higher ductility during dynamic loading. Schmid factor maps demonstrated that shear band formation behavior was in uenced by texturing in these alloys.
Ph.D. in Materials Science and Engineering, May 2015
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- Title
- Electrostatic Recording System Employing Photoconductice Electrodes
- Creator
- Brophy, James J.
- Date
- 4/23/2009, 1967-10-10
- Description
-
Sponsorship: IIT Research Institute
United States Patent
- Title
- PHASE EQUILIBRIA AND THERMODYNAMIC MEASUREMENTS OF SOME HEUSLER COMPOUNDS
- Creator
- Chen, Song
- Date
- 2012-08-14, 2012-07
- Description
-
Heusler alloys are compounds based on the original Heusler phase Cu2MnAl which are ternary intermetallics with a particular chemical...
Show moreHeusler alloys are compounds based on the original Heusler phase Cu2MnAl which are ternary intermetallics with a particular chemical stoichiometric formula X2YZ and face-centered cubic structure. Heusler alloys are of interest because of a range of physical phenomena which may occur in them that can be applied in mechanical or electronic devices, including shape memory property and disorder/order phenomenon. In this work, a high temperature drop calorimeters and Setaram calorimeters were used to obtain the enthalpy of formation and heat capacity of compounds in the Mn-based Heusler compounds (X2MnZ). Lattice parameters of these compounds were determined with XRD, and phase equilibria in these alloy system were studied in this work. Phase transformations were studied with DSC and dilatometry. The work is aimed at populating databases for computational thermodynamics, developing an understanding of alloying and clarifying phase equilibria.
M.S. in Material Science and Engineering, July 2012
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- Title
- Systems, Methods, and Protocols for Process Migration and Group Membership management
- Creator
- Sun, Xian-he, Du, Cong
- Date
- 2014-03-05, 2012-12-18
- Description
-
A system, method, and set of protocols for dynamic group communication are provided for enabling dynamic process migration and dynamic group...
Show moreA system, method, and set of protocols for dynamic group communication are provided for enabling dynamic process migration and dynamic group membership management. A process in a group receives and distributes a migration signal. Group communication continues while the processes in the group asynchronously reach a global superstep and then a synchronization point. The processes then spawn a new process on a new device and update group membership information. The new process operates in continuous execution with the new group.
Sponsorship: Illinois Institute of Technology
United States Patent
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- Title
- Microcomb-Type Magnetic Recording Head
- Creator
- Anderson, Marvin E., Van Scoyoc, James N., Owen, Donald B., Van Den Heuvel, Anthony P.
- Date
- 2009-04-27, 1971-01-05
- Description
-
Sponsorship: IIT Research Institute
United States Patent
- Title
- Apparatus for Electrolytically Determining the Thickness of Metal Coatings
- Creator
- Herbert, William S., Francis, Howard T.
- Date
- 1948-12-28
- Description
-
Sponsorship: Armour Research Foundation of Illinois Institute of Technology
United States Patent
- Title
- Methods for Producing Organic Nanocrystals
- Creator
- Myerson, Allan S., Lee, In Sung
- Date
- 2012-11-01, 2012-10-30
- Description
-
Methods for producing small crystals on islands formed on specialized substrates by, inter alia, subjecting the substrate to a hydrophilic...
Show moreMethods for producing small crystals on islands formed on specialized substrates by, inter alia, subjecting the substrate to a hydrophilic SAMs solution for self-assembling hydrophilic SAMs on certain portions of the substrate surface and subjecting the substrate to a hydrophobic SAMs solution for self-assembling hydrophobic SAMs on certain other portions of the substrate surface.
Sponsorship: Illinois Institute of Technology
United States Patent
Primary US Patent Classification 430/324
International Patent Classification G03F 7/20
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- Title
- THERMODYNAMIC PROPERTIES AND PHASE EQUILIBRIA OF SELECTED HEUSLER COMPOUNDS
- Creator
- Yin, Ming
- Date
- 2015, 2015-12
- Description
-
Heusler compounds are ternary intermetallics with many promising properties such as spin polarization and magnetic shape memory effect. A...
Show moreHeusler compounds are ternary intermetallics with many promising properties such as spin polarization and magnetic shape memory effect. A better understanding of their thermodynamic properties facilitates future design and development. Therefore, standard enthalpies of formation and heat capacities from room temperature to 1500 K of selected Heusler compounds X2YZ (X = Co, Fe, Ni, Pd, Rh, Ru; Y = Co, Cu, Fe, Hf, Mn, Ni, Ti, V, Zr; Z = Al, Ga, In, Si, Ge, Sn) and half-Heusler compounds XYSn (X = Au, Co, Fe, Ir, Ni, Pd, Pt, Rh; Y = Hf, Mn, Ti, Zr) were measured using high temperature direct reaction calorimetry. The measured standard enthalpies of formation were compared with those predicted from ab initio calculations and the extended semiempirical Miedema's model. Trends in standard enthalpy of formation with respect to the periodic classification of elements were discussed. The effect of a fourth element (Co, Cu, Fe, Pd; Ti, V; Al, Ga, In, Si, Ge) on the standard enthalpy of formation of Ni2MnSn was also investigated. Lattice parameters of the compounds with an L21 structure were determined using X-ray powder diffraction analysis. Differential scanning calorimetry was used to determine melting points and phase transformation temperatures. Phase relationships were investigated using scanning electron microscopy with an energy dispersive spectrometer. The isothermal section of the Fe-Sn-Ti ternary system at 873 K was established using equilibrated alloys. Three ternary compounds including the Heusler compound Fe2SnTi were observed. A new ternary compound Fe5Sn9Ti6 was reported and the crystal structure of FeSnTi2 was determined for the first time.
Ph.D. in Mechanical, Materials and Aerospace Engineering
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- Title
- Thermostatic temperature control for gas engine jacket water
- Creator
- Gross, Morton G, Steiner, Albert J.
- Date
- 2009, 1921
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/thermostatictemp00gros
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaves 3-4
- Title
- DEVELOPMENT OF A HIGH ANGULAR RESOLUTION DIFFUSION IMAGING TEMPLATE AND PROBABILISTIC CONNECTIVITY-BASED ATLAS OF THE HUMAN BRAIN
- Creator
- Varentsova, Anna
- Date
- 2016, 2016-05
- Description
-
Digital human brain atlases consisting of MRI-based templates and semantic labels delineating different brain regions serve a critical role in...
Show moreDigital human brain atlases consisting of MRI-based templates and semantic labels delineating different brain regions serve a critical role in neuroimaging, mainly facilitating spatial normalization and automated segmentation for the purposes of voxel-wise, region-of-interest, and network analyses. Diffusion MRI templates contain rich information about the microstructure of the brain, however the accuracy of templates constructed based on the diffusion tensor imaging (DTI) model is limited in regions with complex neuronal microarchitecture. High angular resolution diffusion imaging (HARDI) overcomes limitations of the DTI model and is capable of resolving intravoxel heterogeneity. In this work a method to develop artifact-free HARDI template of the human brain from low angular resolution data is presented. Existing white matter (WM) atlases have been generated either based on anatomical landmarks, thus mixing tracts with substantially different roles, or using DTI tractography, which fails in regions with crossing fibers. Connectivity-based atlases developed using HARDI templates and probabilistic tractography have potential to identify functionally distinct subregions of the brain. This work presents connectivity-based atlas of human brain WM created using HARDI template in ICBM-152 space and a set of FreeSurfer grey matter labels.
Ph.D. in Physics, May 2016
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- Title
- Electromagnetic Transducer Head
- Creator
- Camras, Marvin
- Date
- 1962-09-11
- Description
-
Sponsorship: Armour Research Foundation of Illinois Institute of Technology
United States Patent
- Title
- Magnetic Transducer Head with Single Record Winding and Plural Reproduce Windings
- Creator
- Camras, Marvin
- Date
- 4/23/2009, 1969-09-23
- Description
-
Sponsorship: IIT Research Institute
United States Patent
- Title
- Screech Tones of Supersonic Jets from Bevelled Rectangular Nozzles
- Creator
- Tam, Ckw, Shen, H., Raman, G.
- Date
- 1997-07
- Publisher
- American Inst Aeronaut Astronaut
- Description
-
It is known experimentally that an imperfectly expanded rectangular jet from a thin-lip convergent nozzle emits only a single dominant screech...
Show moreIt is known experimentally that an imperfectly expanded rectangular jet from a thin-lip convergent nozzle emits only a single dominant screech tone. The frequency of the screech tone decreases continuously with an increase in jet Mach number. However, for a supersonic jet issued from a bevelled nozzle or a convergent-divergent nozzle with straight side walls, the shock cell structure and the screech frequency pattern are fairly complicated and have not been predicted before. It is shown that the shock cell structures of these jets can be decomposed into waveguide modes of the jet flow. The screech frequencies are related to the higher-order waveguide modes following the weakest link screech tone theory. The measured screech frequencies are found to compare web with the predicted screech frequency curves.
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- Title
- Relationships Among Twitter Conversation Networks, Language Use, and Congressional Voting
- Creator
- Hemphill, Libby, Otterbacher, Jahna, Shapiro, Matthew A.
- Date
- 2012-12-20, 2012
- Description
-
As Twitter becomes a more common means for officials to communicate with their constituents, it becomes more important that we understand just...
Show moreAs Twitter becomes a more common means for officials to communicate with their constituents, it becomes more important that we understand just how that communication relates to other political activities. Using data from 411 members of Congress' Twitter activity during the summer of 2011, we examine relationships among the resulting conversation networks, language use, and political behavior. The social networks that result from their communications have surprisingly low density and high diameter, indicating a level of independence that is surprising for a group so tightly connected offline. Our findings also indicate that officials frequently use Twitter to advertise their political positions and to provide information but rarely to request political action from their constituents or to recognize the good work of others. Our analysis suggests strong relationships between anti-social behaviors indicated by the loosely connected network and low incidence of pro-social conversations and polarized or extreme Congressional voting records.
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- Title
- Gerry-meandering: An Assessment of the Congressional District Model of Depository Allocation (preprint): AhrensGriffinedrev2
- Creator
- Ahrens, Aric G., Griffin, Luke A.
- Date
- 2003-06
- Description
-
The preprint of a published article dealing with the effect of allocating Federal Depositories by Congressional district. Conclusions drawn...
Show moreThe preprint of a published article dealing with the effect of allocating Federal Depositories by Congressional district. Conclusions drawn include the fact that due to redistricting that occurs after each decennial census, over time some districts may have within their boundaries a greater number than the two depositories that Congressional district allocation was intended to produce. Likewise, over time shifting boundaries of districts have created districts that have no depositories whatsoever.
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- Title
- EXPERIMENTAL STUDY, TIME-RESOLVED OBSERVATION, AND ANALYSIS OF NANOSECOND LASER ABLATION AND LASER-INDUCED PLASMA
- Creator
- Zhou, Yun
- Date
- 2013, 2013-05
- Description
-
For lasers, there exist many current and potential competitive applications in the areas of manufacturing, materials processing, and so on....
Show moreFor lasers, there exist many current and potential competitive applications in the areas of manufacturing, materials processing, and so on. Nanosecond (ns)-pulsed lasers are often seen in these applications. This dissertation presents the experimental study, time-resolved observation and analysis of nanosecond laser ablation and laser-induced plasma due to ablation, and the analysis is based on physics-based numerical models. Specifically, the following topics have been studied: (1). Plasma induced by ablation using long-duration nanosecond laser pulse Plasma is often produced in laser-material interactions, and may play an important role in many laser-based or laser-assisted technologies, such as laser shock peening (LSP), laser micromachining (through the laser ablation process), laser-induced breakdown spectroscopy (LIBS), and laser propulsion, etc. However, despite the previous work in the literature, the study is still limited for the plasma induced by the ablation process using long nanosecond laser pulses (with durations on the order of ~100 ns). In this dissertation, investigations have been performed on this kind of plasma through fast photography (imaging) and emission spectroscopy techniques, and the experimental results have been analyzed using physics-based computational models. Based on the investigations, the following major interesting findings have been obtained under the investigated conditions: (i) Two high radiation intensity regions are observed in the plasma, and one of them disappears soon after laser pulse ends. The research work shows that this phenomenon is related to the vaporization process from the target surface and the confinement effect of the ambient air. (ii) Laser-induced plasma xvii backward growth phenomenon occurs for target ablation using 100-ns laser pulses, but not for that using 200-ns pulses. The investigation shows that the underlying mechanism is the backward growth of the boundary of the high temperature region without actual backward motion of vapor material. (iii) Under the studied conditions, the core region of the plasma (~100 μm above the laser-ablated target) has relatively low temperatures as compared to some other regions of the plasma, which contradicts the common intuition. (2). Semiconductor ablation utilizing infrared (IR) nanosecond laser pulses Semiconductor micromachining through laser ablation may have the advantages of high spatial resolution, high processing efficiency, good flexibility, and no tool wear. However, most of the prior investigations in the literature on ns laser ablation of semiconductors often employ lasers at the ultraviolet (UV) or visible wavelength. The work using IR ns lasers is limited, but IR ns lasers may often have lower cost and require less external energy consumption to produce the same average laser power output. In this dissertation, the ablation of semiconductors using IR ns lasers has been studied through time-resolved observations (fast photography) and the results have been analyzed utilizing physics-based numerical models. The research work shows that the ablation mechanism under the studied conditions is the surface vaporization process during the early stage followed by the subsequent liquid ejection process that occurs at a later time. The research work and analysis shows that the underlying mechanism for the observed liquid ejection should be due to the spatial gradient of the pressure exerted on the target surface, instead of phase explosion. (3). Laser-induced backside ablation (LIBA) of sapphire with IR ns laser pulses xviii LIBA may potentially provide a good solution for high-quality and highefficiency micromachining of wide-band-gap dielectrics (WBGD). However, the prior work on LIBA of sapphire (which is a very important WBGD material) using low-cost IR ns lasers has been rarely reported. This kind of work has been carried out in this dissertation, and the investigation shows that under the studied conditions LIBA can produce very high material removal efficiency and reasonably good quality of machining without obvious chemical contamination coming from the employed backing layer. The ablation rate and damage threshold are measured under different laser parameters, and the research work may provide useful information for the applications of LIBA in practical areas using IR ns lasers that may often have relatively lower cost than UV or visible ns lasers.
PH.D in Mechanical and Aerospace Engineering, May 2013
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- Title
- The yield of acetic acid as influenced by temperature in wood distillation
- Creator
- Marx, Walter L.
- Date
- 2009, 1913
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/yieldofaceticaci00marx
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaf 22
- Title
- Image-based Indexing and Classification in Image Databases
- Creator
- Agam, Gad, Frieder, Ophir
- Date
- 2012-03-20, 2010-08-31
- Description
-
The invention enables the digital management of large scale image databases, to efficiently classify and index image data independent of...
Show moreThe invention enables the digital management of large scale image databases, to efficiently classify and index image data independent of language. Complex processing requirements are required only on reduced and operably small subsets of the entire collection, thereby effectively scaling large document collections. Embodiments of the present invention provide image-based classification and retrieval of documents based on image recognition, e.g., signatures, logos, stamps, or word-spotting; in documents within real time for large datasets such as in the millions of documents.
Sponsorship: Illinois Institute of Technology
United States Patent
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- Title
- Apparatus for Generating Generally Uniform Compression in High-Viscosity Fluids
- Creator
- Venerus, David C., Kompani, Mandana
- Date
- 2009-05-11, 1999-06-29
- Description
-
An apparatus for generating generally uniform compression forces over a film of a relatively low-viscosity liquid by passing the low-viscosity...
Show moreAn apparatus for generating generally uniform compression forces over a film of a relatively low-viscosity liquid by passing the low-viscosity liquid through a porous plate, from an upstream face to a downstream face of the porous plate. The porous plate has a specified porosity and arrangement of the through holes or other pores that results in forming a uniform pressure through and uniform compression forces over a film of the low-viscosity liquid that is at or near the upstream face of the porous plate. The apparatus of this invention results in homogeneous deformation of a material, such as molten polymer, polymer solution, multiphase polymer systems, asphalts or foods.
Sponsorship: Illinois Institute of Technology
United States Patent
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- Title
- Spraying Process
- Creator
- Bradstreet, Samuel W., Griffith, James S.
- Date
- 1956-09-18
- Description
-
Sponsorship: Armour Research Foundation of Illinois Institute of Technology
United States Patent