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- Title
- TOPOLOGY OPTIMIZATION OF SYNCHRONOUS ELECTRIC MACHINES
- Creator
- Guo, Feng
- Date
- 2021
- Description
-
Topology optimization of electric machine is attractive because of the increased design degree of freedom compared to conventional electric...
Show moreTopology optimization of electric machine is attractive because of the increased design degree of freedom compared to conventional electric machine design techniques. Also, a topology optimization approach does not necessarily require the use of a geometric template where dimensions are controlled by parameters. In this dissertation, a density-based magneto-structural topology optimization approach for the design of synchronous reluctance machine (SynRel), interior permanent magnet synchronous machine (IPMSM), and wound field synchronous machine (WFSM) rotors is developed. Depending on the electric machine type, the optimization problems are divided into single material and multi-material topology optimizations. A mass thresholding function is introduced to overcome the intermediate density issue which is caused by combining the magnetic and structural topology optimization problems. SynRel and IPMSM optimization examples are presented in the single material topology optimization section. For the multi-material topology optimization, in order to properly define the boundary conditions between multiple materials, a virtual region calculation approach is proposed. In the WFSM topology optimization, the copper field winding is represented by a virtual region. The contact and frictionless boundary conditions between the copper field winding and the electrical steel is defined and the centripetal load of the copper winding are equivalently calculated and applied on the elements on the electrical steel next to the boundary between the copper field winding and the steel of the WFSM pole tip. In additional to the total free-form magneto-structural topology optimization, a density-based combined dimensional and topology optimization is developed for the design of IPMSM and WFSM rotors. Both the dimensional and topological control variables are integrated to simplify the optimization problem. For IPMSM rotor design, the permanent magnet (PM) block shape is preferred to be retained where dimensional optimization could be used. The proposed dimensional topology optimization approach can fit in this design situation, where the PM is designed using dimensional control variables where the rest of the design domain is optimized using topology optimization. To allow the block or rectangular magnet to move and change size, the surrounding design domain mesh must deform or distort. The Laplace's smoothing mesh deformation technique is used in this approach and helper lines are connected to allow greater mesh deformation range and to avoid over mesh distortion. In addition to IPMSMs, a WFSM example is presented optimizing the winding region using dimensional optimization and the rotor core using topology optimization. An alternative combined dimensional and topology optimization approach has also been developed primarily for the design of the IPMSM rotors. In this approach, the mesh deformation is not required but there is no explicit geometric boundary between the rectangular permanent magnet and the surrounding electrical steel and air. In this approach, the PM density is expressed as a Heaviside rectangular function of dimensional variables. The function is projected onto the rotor mesh. Modified material penalizations are used. Topology optimization then controls the deposition of electrical steel and air. Three different IPMSM examples are presented with different dimensional control variables, including the PM position, size and angle.
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- Title
- Child Temperament, Attachment, and Loneliness: The Mediating Effects of Social Competence
- Creator
- Evans, Lindsey M
- Date
- 2021
- Description
-
Chronic loneliness is a risk factor associated with adverse psychological, physical, and academic outcomes. Converging evidence suggests that...
Show moreChronic loneliness is a risk factor associated with adverse psychological, physical, and academic outcomes. Converging evidence suggests that young children experience and can reliably report on their own loneliness. Due to the significant negative sequalae associated with childhood loneliness, it is critically important to examine risk factors for child loneliness. The aims of this study were two-fold: (a) to examine if temperament (i.e., negative affect, effortful control, and inhibitory control) and attachment security assessed at 4 years of age predict loneliness at age 6; and (b) to determine if social competence at age 5 mediates the relation between temperament and attachment security at age 4 and loneliness at age 6. Participants included a diverse sample of 796 4-year old children, about half of whom were male. At age 4, temperament was assessed with the Rothbart Child Behavior Questionnaire and three inhibitory control tasks, and attachment security was assessed with the Attachment Q-Sort. At age 5, the Social Skills Rating Scale was used to assess social competence, and, at age 6, loneliness was assessed with the Loneliness and Social Dissatisfaction Questionnaire. Results of hierarchical regression analyses indicated that lower levels of effortful control and inhibitory control at age 4 significantly predicted higher levels of loneliness at age 6. Also, lower levels of negative affect and higher levels of effortful control and attachment security at age 4 significantly predicted higher levels of social competence at age 5. However, social competence at age 5 did not predict loneliness at age 6. There was no evidence that social competence at age 5 mediated the relation between age 4 temperament, attachment security and age 6 loneliness. These findings reveal that early self-regulation is associated with later child-reported loneliness and that intervention for children who struggle with cognitive regulation may be effective in decreasing risk for later loneliness.
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- Title
- Inviscid Shock Propagation within a Variable-Geometry Scramjet Inlet
- Creator
- Grybko, Maciej
- Date
- 2021
- Description
-
The study concerns the propagation of shockwaves within an inlet of a scramjet engine and effect of inlet geometry variation on performance. A...
Show moreThe study concerns the propagation of shockwaves within an inlet of a scramjet engine and effect of inlet geometry variation on performance. A Python code was developed to simulate and visualize a flowfield within a scramjet inlet, based on inviscid oblique shock theory. The program was validated against NASA Shock software, and the results differed only by round-off error (0.05%). Subsequently a geometric sensitivity study was conducted, showing that throughout acceleration from Mach 5 to Mach 20 parameters like inlet height could be varied to ensure constant number of shocks within an inlet (preventing discontinuous changes of flowfield), whereas lower wedge angle could control compression required for optimal combustion. Correspondingly, a trajectory was determined with a constraint on static pressure entering combustion chamber (100 kPa). For an arbitrary baseline inlet geometry, it was established that beyond Mach 10 the scramjet would exceed structural load limit, despite delivering sufficient conditions for rapid combustion. Nevertheless, below Mach 10 it would operate efficiently, proving that hydrocarbon-fueled scramjets can have a fixed geometry. For higher speeds, a variable geometry is a necessity.
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- Title
- ARE SUPPORTIVE FOSTER CAREGIVERS ASSOCIATED WITH IMPROVED FOSTER CARE ALUMNI OUTCOMES? A LONGITUDINAL EXAMINATION OF THE EFFECT OF SUPPORTIVE FOSTER CAREGIVERS ON MENTAL HEALTH OUTCOMES IN A NATIONALLY REPRESENTATIVE SAMPLE
- Creator
- Dunn, Megan Reeves
- Date
- 2021
- Description
-
Foster youth are a vulnerable population associated with poor health outcomes, but relatively little research has identified factors that may...
Show moreFoster youth are a vulnerable population associated with poor health outcomes, but relatively little research has identified factors that may mitigate adverse outcomes for these youth. The present study augments previous research by utilizing a nationally representative, longitudinal study (The National Longitudinal Study of Adolescent to Adult Health or Add Health) to investigate whether foster youth in the United States face significantly different mental and behavioral health outcomes compared with same-age peers, and second, whether presence of a supportive foster caregiver may predict better mental and behavioral health outcomes in the foster youth subsample. Using data from Waves III and IV of the Add Health study (N = 12,288 participants, of which n = 282 were foster youth), analyses examined whether foster status and higher caregiver support was related to rates of depression symptoms, suicidal ideation, marijuana use, and alcohol use. Surprisingly, there were few differences between those with and without a foster history; higher frequency of marijuana use among foster youth was the only significant difference. However, analyses in the foster youth subsample indicated that the presence of a supportive caregiver was associated with lower rates of depression symptoms and lower endorsement of suicidal ideation, demonstrating caregiver support as a possible protective factor for foster youth. Future research must continue to explore potential benefits of caregiver support, as it may inform policy that can improve long-term outcomes for foster youth.
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- Title
- THE EFFECTS OF MODIFIED SURFACES ON INSULIN CRYSTALLIZATION
- Creator
- Hammadi, Okba Tahar
- Date
- 2021
- Description
-
Engineered nucleation features (ENFs) were designed with the hope to improve the efficiency of protein crystallization and increase...
Show moreEngineered nucleation features (ENFs) were designed with the hope to improve the efficiency of protein crystallization and increase reproducibility both in quality and quantity. These ENFs were tested with human insulin as the protein of choice since it has flexible parameters, only one cofactor, and a large amount of commercially available crystal ready protein. Insulin crystallization on the ENFs will produce more crystals while also having a reduced crystallization on-set time compared to the control glass surface. The ENFs were compared to control surfaces under similar conditions and observed over time to record both onset-times and end times. The ENFs performed markedly better in on-set times, having an overall 87%-time reduction when compared to the control drops. The drops placed on the ENF produced more than 2.5x the number of crystals in the control drops.
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- Title
- THE EFFECTS OF COMMUNICATION MODALITY ON PRESENCE, COGNITIVE LOAD AND RETENTION IN SECOND LIFE
- Creator
- WILKES, STEPHANY FILIMON
- Date
- 2009-12
- Description
-
This thesis reports findings from a study (N = 60) of the impact of three communication modalities (voice only, text only, and voice and text...
Show moreThis thesis reports findings from a study (N = 60) of the impact of three communication modalities (voice only, text only, and voice and text simultaneously) on cognitive load, as measured by subjective reports of mental effort; on learning, as measured by tests of recall and retention; and on perceptions of presence as measured by a Presence Questionnaire (Witmer & Singer, 2005). Based on the results of prior empirical research, it is hypothesized that retention scores will be higher for voice participants and voice-and-text participants than for text-only participants; that cognitive load will be lower for voice participants and higher for text conditions; that voice will contribute to greater perceptions to presence; and that higher perceptions of presence will not correlate with deeper learning. Study results indicate that communication modality significantly effected cognitive load (F(2, 54) = 4.58, p = .01) and retention (F(2, 54) = 3.53, p = .04), and that experience with and time spent in the virtual environment had significant effects on measures of cognitive load, retention, and presence: Significant between-subjects effects were found for cognitive load and time (p = .23), for retention and time (p = .21), and for retention and experience (p — .03).
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- Title
- Basketball in Keating Hall, Illinois Institute of Technology, Chicago, Illinois, 1980s
- Date
- 1980-1989
- Description
-
Photograph of students playing basketball in the Keating Sports Center gymnasium. Photographer unknown. Date of photograph unknown. Date range...
Show morePhotograph of students playing basketball in the Keating Sports Center gymnasium. Photographer unknown. Date of photograph unknown. Date range listed is approximate.
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- Office of Communications and Marketing photographs, 1905-1999
- Title
- Basketball in Keating Hall, Chicago, Illinois, 1970s
- Date
- 1970-1979
- Description
-
Photograph of Illinois Institute of Technology's basketball team practicing in the Keating Sports Center gymnasium. Photographer unknown. Date...
Show morePhotograph of Illinois Institute of Technology's basketball team practicing in the Keating Sports Center gymnasium. Photographer unknown. Date of photograph unknown. Date range listed is approximate.
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- Office of Communications and Marketing photographs, 1905-1999
- Title
- Basketball game in Keating Hall, Illinois Institute of Technology, Chicago, Illinois, ca. 1970s
- Creator
- Illinois Institute of Technology
- Date
- 1970-1979
- Description
-
Photograph of tip-off at a basketball game between Illinois Tech and Roosevelt University in Keating Hall. Date of photograph is unknown. Date...
Show morePhotograph of tip-off at a basketball game between Illinois Tech and Roosevelt University in Keating Hall. Date of photograph is unknown. Date range listed is approximate.
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- Office of Communications and Marketing photographs, 1905-1999
- Title
- North Hall, Illinois Institute of Technology, Chicago, Illinois, ca. 1960
- Creator
- Illinois Institute of Technology
- Date
- 1960
- Description
-
Photograph of North Hall, located at 71 East 32nd Street, Chicago, Ill. The building was designed by Mittelbusher & Tourtelot, and was...
Show morePhotograph of North Hall, located at 71 East 32nd Street, Chicago, Ill. The building was designed by Mittelbusher & Tourtelot, and was constructed in 1959. Date of photograph is unknown. Date range listed is approximate.
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- Office of Communications and Marketing photographs, 1905-1999
- Title
- Institute of Gas Technology, Illinois Institute of Technology, Chicago, Illinois, ca. 1950s
- Date
- 1950-1959
- Description
-
Photograph of the Institute of Gas Technology's North Building, designed by Ludwig Mies van der Rohe. The building is located at 3410 South...
Show morePhotograph of the Institute of Gas Technology's North Building, designed by Ludwig Mies van der Rohe. The building is located at 3410 South State Street, and was constructed 1947-1950. Photographer unknown. Date of photograph is unknown. Date range listed is approximate.
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- Office of Communications and Marketing photographs, 1905-1999
- Title
- Commons Building site clearance, Illinois Institute of Technology, Chicago, Illinois, ca. 1952
- Date
- 1952
- Description
-
Photograph of the future site of the Commons Building at 32nd Street and State Street. Photographer unknown. Date of photograph is unknown....
Show morePhotograph of the future site of the Commons Building at 32nd Street and State Street. Photographer unknown. Date of photograph is unknown. Date listed is approximate.
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- Office of Communications and Marketing photographs, 1905-1999
- Title
- Reginald Malcolmson with model of "Metro-Linear: the Regional Metropolis," Illinois Institute of Technology, Chicago, Illinois, ca. 1960
- Creator
- Ryan, Dan
- Date
- 1960
- Description
-
Malcolmson studied under Mies van der Rohe at IIT from 1947-49, and taught in architecture department from 1949-1964. Date of photograph is...
Show moreMalcolmson studied under Mies van der Rohe at IIT from 1947-49, and taught in architecture department from 1949-1964. Date of photograph is unknown. Date listed is approximate.
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- Office of Communications and Marketing photographs, 1905-1999
- Title
- Henry Heald, Ludwig Mies van der Rohe, and James Cunningham at Mies' appointment dinner, Chicago, Illinois, 1938
- Creator
- Foto-Ad
- Date
- 1938-10
- Description
-
Photograph of (L-R) Henry Heald (President of the Armour Institute of Technology), Ludwig Mies van der Rohe, and James Cunningham (chairman of...
Show morePhotograph of (L-R) Henry Heald (President of the Armour Institute of Technology), Ludwig Mies van der Rohe, and James Cunningham (chairman of the Armour Institute of Technology Board of Trustees) at a banquet to honor Mies and his appointment as head of the Armour Institute's Department of Architecture at the Palmer House hotel. Photograph labeled as property of Public Relations.
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- Office of Communications and Marketing photographs, 1905-1999
- Title
- Ludwig Mies van der Rohe with students James Speyer (left) and George Danforth (right), fourth year studio critique, 1939.
- Date
- 1939
- Description
-
Ludwig Mies van der Rohe with students James Speyer (left), George Danforth (right), and other unidentified students at an architecture studio...
Show moreLudwig Mies van der Rohe with students James Speyer (left), George Danforth (right), and other unidentified students at an architecture studio critique in 1939. Photographer unknown.
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- Office of Communications and Marketing photographs, 1905-1999
- Title
- North Hall, Illinois Institute of Technology, Chicago, Illinois, ca. 1965
- Date
- 1963-1969
- Description
-
Photograph of North Hall, located at 71 East 32nd Street, Chicago, Ill. The building was designed by Mittelbusher & Tourtelot, and was...
Show morePhotograph of North Hall, located at 71 East 32nd Street, Chicago, Ill. The building was designed by Mittelbusher & Tourtelot, and was constructed in 1959. Date of photograph is unknown. Date range listed is approximate. Photographer unknown.
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- Office of Communications and Marketing photographs, 1905-1999
- Title
- Alfred Caldwell with students, Illinois Institute of Technology, Chicago, Illinois
- Date
- 1944-1959
- Description
-
Photographer unknown. Date of photograph is unknown. Date range listed is approximate.
- Collection
- Office of Communications and Marketing photographs, 1905-1999
- Title
- Machinery Hall, Illinois Institute of Technology, Chicago, Illinois, ca. 1962-1979
- Date
- 1962-1979
- Description
-
Photographer unknown. Date of photograph unknown. Date range listed is approximate.
- Collection
- Office of Communications and Marketing photographs, 1905-1999
- Title
- Carr Chapel interior with wall hangings, Illinois Institute of Technology, Chicago, IL, 1978
- Date
- 1978
- Description
-
Photograph of the interior of Carr Chapel with hangings on the walls depicting Noah's Ark. Photographer unknown.
- Collection
- Office of Communications and Marketing photographs, 1905-1999
- Title
- Engineering 1 Building at night, Illinois Institute of Technology, Chicago, Illinois, ca. 1970
- Date
- 1970
- Description
-
Photograph of Engineering 1 building, designed by Myron Goldsmith of Skidmore, Owings & Merrill. The building is located at 10 West 32nd...
Show morePhotograph of Engineering 1 building, designed by Myron Goldsmith of Skidmore, Owings & Merrill. The building is located at 10 West 32nd Street. The building was renamed John T. Rettaliata Engineering Center in 2015. Photographer unknown. Date of photograph is unknown. Date listed is approximate.
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- Office of Communications and Marketing photographs, 1905-1999