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Title: IIT 1956-1957
Creator: Illinois Institute of Technology
Date: 1956-1957
Description: Black-and-white, silent film identified as "IIT 1956-1957" with images of Illinois Institute of Technology campus and buildings, classroom...
Show moreBlack-and-white, silent film identified as "IIT 1956-1957" with images of Illinois Institute of Technology campus and buildings, classroom scenes, and students working in laboratories. Extended sequences feature architecture and Institute of Design students with models of their work and students dining in the Commons Building. Original format is 16mm film. Exact date of filming is unknown, but some evidence indicates at least smoe of the film was shot in spring, 1957.
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Collection: IIT 1956-1957 film, 1956-1957

Title: Josephine Mehlberg, ca. 1960
Creator: Illinois Institute of Technology
Date: 1960-1969
Description: Photograph of Professor Josephine Mehlberg teaching a mathematics class. Photographer was possibly Dan Ryan. Date of photograph is unknown....
Show morePhotograph of Professor Josephine Mehlberg teaching a mathematics class. Photographer was possibly Dan Ryan. Date of photograph is unknown. Date range listed is approximate.
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Collection: Dan Ryan collection, 1954-1980

Title: Josephine Mehlberg, ca. 1960
Creator: Illinois Institute of Technology
Date: 1960-1969
Description: Photograph of Professor Josephine Mehlberg teaching a mathematics class. Photographer was possibly Dan Ryan. Date of photograph is unknown....
Show morePhotograph of Professor Josephine Mehlberg teaching a mathematics class. Photographer was possibly Dan Ryan. Date of photograph is unknown. Date range listed is approximate.
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Collection: Dan Ryan collection, 1954-1980

Title: Josephine Mehlberg, ca. 1960
Creator: Illinois Institute of Technology
Date: 1960-1969
Description: Photograph of Professor Josephine Mehlberg teaching a mathematics class. Photographer was possibly Dan Ryan. Date of photograph is unknown....
Show morePhotograph of Professor Josephine Mehlberg teaching a mathematics class. Photographer was possibly Dan Ryan. Date of photograph is unknown. Date range listed is approximate.
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Collection: Dan Ryan collection, 1954-1980

Title: Student protest at Illinois Institute of Technology, 1970
Creator: Illinois Institute of Technology
Date: 1970
Description: Photograph of Illinois Institute of Technology president John Rettaliata at an open meeting with students and faculty regarding the student...
Show morePhotograph of Illinois Institute of Technology president John Rettaliata at an open meeting with students and faculty regarding the student protests that occurred on IIT's campus following the fatal shooting of four students at Kent State University by the Ohio National Guard on May 4, 1970.
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Collection: John T. Rettaliata student protest photographs, 1970

Title: Robert F. Carr Memorial Chapel of St. Savior
Creator: Strohm, Adam
Date: 2015
Description: 65 East 32nd Street. Chicago, Illinois
Collection: Building History project (buildinghistory.iit.edu)

Title: To Hell and Back
Creator: Sessions, Richard
Date: 2011
Description: Richard Sessions, who received an MS in Design in 1960 from the Institute of Design, provides a written account of his experience as a student...
Show moreRichard Sessions, who received an MS in Design in 1960 from the Institute of Design, provides a written account of his experience as a student under Frederick Sommer between 1957 and 1958. Included are Sessions' three photographs inspired by Sommer: "There ARE angels in America," "To Hell and Back," and "Breaking Up."
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Collection: Institute of Design Photography Oral History Project, 2011

Title: Breaking Up
Creator: Sessions, Richard
Date: 2011
Description: Richard Sessions, who received an MS in Design in 1960 from the Institute of Design, provides a written account of his experience as a student...
Show moreRichard Sessions, who received an MS in Design in 1960 from the Institute of Design, provides a written account of his experience as a student under Frederick Sommer between 1957 and 1958. Included are Sessions' three photographs inspired by Sommer: "There ARE angels in America," "To Hell and Back," and "Breaking Up."
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Collection: Institute of Design Photography Oral History Project, 2011

Title: There ARE angels in America
Creator: Sessions, Richard
Date: 2011
Description: Richard Sessions, who received an MS in Design in 1960 from the Institute of Design, provides a written account of his experience as a student...
Show moreRichard Sessions, who received an MS in Design in 1960 from the Institute of Design, provides a written account of his experience as a student under Frederick Sommer between 1957 and 1958. Included are Sessions' three photographs inspired by Sommer: "There ARE angels in America," "To Hell and Back," and "Breaking Up."
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Collection: Institute of Design Photography Oral History Project, 2011

Title: EXPERIMENTAL AND STRUCTURAL STUDIES OF FDA APPROVED EXON SKIPPING TREATMENT DRUGS
Creator: Zhang, Jingwen
Date: 2021
Description: DMD is an X-chromosome related genetic disease caused by loss of dystrophin protein expression, and which impacts 1 in 5000 boys born in the...
Show moreDMD is an X-chromosome related genetic disease caused by loss of dystrophin protein expression, and which impacts 1 in 5000 boys born in the world. The usual cause of this at the genetic level is a frame shift due to internal deletions of one or more exons that results in a change of the reading frame. This results in loss of expression of the protein encoded by this gene, dystrophin, which in turn leads to the disease phenotype. Exon skipping is a therapy for DMD which restores dystrophin pre-mRNA reading frame to produce a modified dystrophin. This is done by antisense oligonucleotides, AONs, which disturb the process of exon splicing and exclude targeted exons near the patient’s defect which restore the correct reading frame in the pre-mRNA transcript. In 2016, the first AON was approved for clinical use targeting exon 51, called eteplirsen. This provided the first disease modifying therapy for DMD, but it was only relevant to ~6% of patients who had defects that were correctable by skipping this specific exon. In 2020 two more AONs targeting exon 53 were developed, viltolarsen and golodirsen, providing benefit to an additional 5% of patients, and in 2021 casimersen targeting exon 45 was approved.However, this raises an interesting issue, in that for some patients, with an exon 52 deletion, skipping exon 51 or skipping exon 53 could both restore the reading frame. Which approved exon skipping treatment is better and the differences between them are still unknown. This is the aim of this study: to help patients figure out which AON can have a consequence of less long-term health problems like cardiomyopathy and longer life and get more precise treatment. We selected three exon skipped edits – two that represent exon 53 skipping repair of an underlying Δe52 defect and one targeting exon 51 skipping repair of a Δe52 defect. We then used a panel of biophysical and biochemical including dynamic light scattering, circular dichroism Spectroscopy, thermal denaturation, and protease K challenge to investigate the biophysical characteristics of these different exon skipped edits. From our results we found that Δe51-52 has the more structure (i.e., is less perturbed), compared to e52-53, as assessed by CD or by proteinase K challenge, but it also has lower thermal stability, with a low Tm=48C transition that begins to unfold at the physiological relevant temperature of 37C. On the other hand, e52-53 has less helical structure, but what structure did form had unfolding transitions in the normal range for wild type STRs, Tm> 60C; but this edit also had more non-helical structure. So, the total experimental results of these three edits are very complex, which may be due to the fact that these edits span the normally unfolded H3 region.
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Title: Two Essays on Corporate Finance
Creator: Wang, Bo
Date: 2021
Description: This dissertation is comprised of two essays on finance. In the first chapter, I investigate whether and to what extent unionization would...
Show moreThis dissertation is comprised of two essays on finance. In the first chapter, I investigate whether and to what extent unionization would influence the compensation to the non-executive employees. In the second chapter, I explore how social capital would impact regional innovation performance by private firms.In the first chapter, I examine the effects of unionization on stock options granted to non-executive employees. Adopting a regression discontinuity design, I find that employees receive more stock options after the union election wins. The positive association is more pronounced when unions have more bargaining power and when free-riding problems are less severe. Further, I provide evidence that employees receive more stock options when CEOs are entrenched. Finally, I show that stock options provide risk-taking incentives to non-executive employees. This work provides a potential explanation to the union wage premium puzzle that unions utilize stock options to increase non-executive employees’ total compensation. In the second chapter, I investigate whether and to what extent social capital may affect regional innovation by private firms in the U.S. I document that regional social capital is positively associated with the quantity, quality, and novelty of county-level innovation by private firms. This effect is more prominent in regions with a lower supply of financial capital. My findings further suggest that social capital is complementary to investment in research and development. Using a Spatial Durbin Model, I report that regional social capital has significant spillover effects in boosting the innovation of neighboring counties.
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Title: RESIDENTIAL LOAD DATA COMPRESSION AND LOAD DISAGGREGATION
Creator: Xu, Runnan
Date: 2021
Description: Non-Intrusive Load Monitoring (NILM) for residential applications aims to dis-aggregate the total electricity consumption of a household into...
Show moreNon-Intrusive Load Monitoring (NILM) for residential applications aims to dis-aggregate the total electricity consumption of a household into the single appliance information. For the customer side, users can change their consumption habit and save more electricity. For the utility, generation scheduling will be more accurate, efficient, and secure. Furthermore, energy management system, demand response and fault diagnosis will benefit from the real time information provided by the NILM. This dissertation first proposes a data compressed method suitable for the NILM data. Then a real time disaggregation based on the Kalman filter is proposed to obtain the appliance state information. A model-free lossless data compression method for time series in smart grids (SGs), namely, Lossless Coding considering Precision (LCP) method is proposed. The LCP method encodes the current datapoint only using the immediate previous datapoint by differential coding, XOR coding, and variable length coding and transmits the encoded data once generated. It does not use the dynamics (e.g., many previous datapoints) or prior knowledge (e.g., mathematical models) of the time series. It considers the patterns, potential applications, and associated precision to preprocess the time series and especially suits high-resolution time series with long steady periods. The LCP method features low-latency and generalizability which enables real-time data communication for different time-critical tasks. Sub-metered load profiles in REDD dataset, high-resolution LIFTED dataset, AMPds dataset and PMU dataset are used to evaluate the performance of the LCP method. The results show that the LCP method demonstrates high compression ratio, low latency, and low complexity compared to state-of-the-art Resumable Data Com-pression (RDC) method, DEFLATE based on LZ77 & Huffman coding, and Lempel-Ziv-Markov Chain Algorithm (LZMA). An online method based on the transient features of individual appliances and system steady-state characteristics is proposed to estimate the appliances’ working states. It determines the number of states for each appliance via Density-based Spatial Clustering of Applications with Noise (DBSCAN) method and models the transition relationship among different states. The states of working appliances are identified from aggregated power signals by implementing the Kalman filtering method into the Factorial Hidden Markov Model (FHMM) and by the verification of system states which are the combination of working states of individual appliances. The proposed method is event based and the use of transient features extracted from event detection could achieve fast state inference and is suitable for online load disaggregation. The proposed method is tested on high-resolution dataset such as LIFTED and outperforms other related methods, including Segment-wise Integer Quadratic Constraint Programming (SIQCP), Combinatorial Optimization (CO), and the exact FHMM (FHMM_EXACT), in terms of accuracy, f1 score, and computational time.
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Title: Testing a pilot intervention aiming to increase transgender allyship among future healthcare providers
Creator: Yoder, Wren
Date: 2021
Description: Transgender individuals often experience poor health outcomes related to a lack of provider knowledge and comfort around transgender issues. ...
Show moreTransgender individuals often experience poor health outcomes related to a lack of provider knowledge and comfort around transgender issues. Ally identity development and cultural humility theories have been used to develop interventions shown to improve attitudes, knowledge, and skills related to being an ally to the transgender community. Additionally, healthcare providers have reported a desire for online tools related to transgender healthcare, and online interventions can be more cost effective than traditional in-person trainings. The current study developed an hour-long online intervention composed of six activities aiming to increase attitudes, knowledge, skills, and identification as an ally to the transgender community. Tests were conducted to assess whether these domains increased significantly from baseline to post in the intervention condition compared to the control condition and whether the increase was maintained at 2-week follow up. The sample included cisgender (i.e., male or female) students studying a subject related to healthcare recruited online through Prolific (N = 78). Results indicated that knowledge and skills increased significantly from baseline to post in the intervention condition compared to the control condition, and increases were maintained at 2-week follow up. However, this was not the case for attitudes and identity. These findings largely replicate existing research on knowledge about transgender individuals and provide new insights into skills, attitudes, and identity related to transgender allyship. Findings can inform future research on transgender allyship intervention design and allyship theory as well as support improvements in clinical practice and policy related to transgender healthcare services.
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Title: HIGH-THROUGHPUT FIRST-PRINCIPLES STUDY ON HIGH-ENTROPY ALLOYS
Creator: Zhang, Jie
Date: 2021
Description: This research thesis discusses the current ecosystem surrounding a new type of alloy: high entropy alloys (HEA) or multi-element crystalline...
Show moreThis research thesis discusses the current ecosystem surrounding a new type of alloy: high entropy alloys (HEA) or multi-element crystalline materials and lays out the high-throughput first-principles calculation as a valuable approach to study these materials. The density function theory (DFT) from computational material science prospect was implemented to investigate the HEAs. Using EMTO-CPA algorithm, high-throughput DFT calculations were conducted. A total of 1958 HEA systems including equimolar and non-equimolar systems were studied with respect to the varies properties, including lattice parameters, bulk moduli, elastic constants, and elastic anisotropy. The first-principles HEA dataset was employed as the training set for the DeepSets a machine learning model. DeepSets, in combination with EMTO-CPA high-throughput calculation, successfully predicted the mechanical properties of specific HEA composition. This paves a promising new path of designing, investigating, and validating the HEA system compared to the time-consuming conventional HEA design method. The doping effect of Vanadium (V) and Titanium (Ti) to NbMoTaW HEA, as well as V or Ti as the fifth element with different molar fraction to the NbMoTaW HEA system, were studied. The phase stability of the new systems was discussed and concluded that all proposed systems tend to form single-phase solid solution. Though the addiction of V only slightly enhances the system’s ductility, the addition of Ti not only enhances the quinary system NbMoTaWTiX (X =0.25, 0.5,0.75, 1.0) ductility, but enables the system to be closer to fully isotropic.
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Title: Drawing on Darwinism: Rewriting the Origin of Louis Sullivan's Idea
Creator: Frey, Syan
Date: 2021
Description: To observe that the unique architectural ornaments that make up the body of work of Louis Henri Sullivan (1856-1924) emulate nature is to...
Show moreTo observe that the unique architectural ornaments that make up the body of work of Louis Henri Sullivan (1856-1924) emulate nature is to state a reality so obvious that it is both pedantic and droll. To use the double entendre that those natural forms drew on Darwinism, however, is to make several more specific claims. First, it can be credibly established that the system of architectural ornament that was the primary contribution of Louis Sullivan to the discipline of architecture was directly inspired by Sullivan’s synthesis of the thesis of natural selection contained within the pages of Asa Gray’s botanical manual. Second, the circumstances of that moment of synthesis reveal that the reason for Sullivan’s Darwinism was not merely the desire to emulate nature, but rather to signify the end of faith. Finally, Sullivan’s synthesis of various Darwinisms drew not only on the thesis for his own artistic inspiration, he drew on the substance of Darwin’s arguments to formulate a secular theory of the nature of inspiration and the technique of design. In the years following, this theory has become the primary technique by which design is taught.Louis’ unique education, which was tied to Darwinism from the very beginning, gave him an unusual perspective on the challenges of architectural design in the industrial age. The economic circumstances of his life as a first-generation immigrant exposed him to just the right education to lead him to explore evolutionary science as the inspiration for design. To be clear, the content of the thesis of natural selection was entirely irrelevant to the theory and practice of architecture in the nineteenth century. Yet by the end of the century the broad consensus among architects, historians, and theorists alike was that there was a, “close and causal relationship,” between Darwinism and modern architecture. Sullivan’s theory drew on Darwinian ideas to dismiss theological styles as empty formalisms, reveal the racism of ethnographic accounts for architectural forms, and argue for the evolution of an American Architecture, liberated from its colonialist origins. The context within which that shift occurred is significant. The justification for nearly every work of architecture in human history prior to the middle of the nineteenth century was some form of god. Mid-nineteenth century architecture in the United States was composed of a variety of regional ethnic styles intended to represent the ethnic origins, religious affiliations, moral inclinations, and nationalist allegiances of an array of displaced immigrant communities. The Civil War laid bare the reality that such ethnic styles represented a segregationist and racialized idea of the modern world. Over the course of the late nineteenth century, the profession of architecture was forced to abandon theological justifications for the practice of architecture as scientifically invalid, morally corrupt, and motivated by racism. This was Sullivan’s full idea: Put instinct before reason in priority, and engage in the iterative analysis of various instincts about the situation. Observe the patterns that emerge. Explore those instincts, until you find that your patterns merge with universal patterns. Do not fear error, as it makes the work alive. The capacity to capture that living essence is in all of us, individually and collectively, not some external force. The most-right instincts are ones in which the resulting form is a demonstration of its function. To understand what Sullivan meant with this we must see it as a Darwinian idea. Instinct is an animal property, a capacity which we share with other species. For Darwin, this sharing of instinct is essential for interspecies empathy. The antithesis of instinct is reason, which Sullivan describes as secondary. Reason is cold and lifeless, but also correct. True reason, Sullivan claims, is learned by experiment, and example. The greatest art speaks not just to our reason, but to our instinct. This, then is the task of the designer – to temper instinct with reasoned evaluation. Sullivan argues that it begins with an intuition, an idea he drew from Darwin’s Descent of Man.
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Title: Sex Differences in a Network Model of Depressive Symptoms
Creator: Ginger, Emily J
Date: 2021
Description: Major Depressive Disorder (MDD) is one of the most prevalent mental health disorders, with a lifetime prevalence rate of 13-16% and 12-month...
Show moreMajor Depressive Disorder (MDD) is one of the most prevalent mental health disorders, with a lifetime prevalence rate of 13-16% and 12-month prevalence rates of 5-7%. It has long been established that the rates of MDD in females is two to three times that of males. Previous research has examined sex differences in the occurrence and severity of MDD symptoms, primarily indicating greater severity of appetite increase and weight gain in females compared to males. The majority of previous research has been conducted assuming the latent factor model that MDD accounts for the symptoms of depression, and sex operates as a mediator or moderator between the latent variable and MDD, or between MDD and its symptoms. The present study used network analysis to examine whether there are sex differences in the relations between symptoms of depression, which might be an important factor for understanding sex differences in prevalence rates of MDD. The present study compared networks of DSM MDD symptoms between currently depressed females and males, and separate networks that also included other symptoms commonly associated with depression (e.g., anxiety, anger). Sex differences were examined using jointly estimated networks, and a Network Comparison Test (NCT) for the independently estimated networks. Results indicated no sex differences in depression symptom networks. These results indicate that depressive symptom networks, or the relations between symptoms are not an important factor for understanding the disparity in sex differences in MDD prevalence rates. Interestingly, non-DSM symptoms were among the strongest and most important symptoms within the network, suggesting future research and diagnostic criteria should consider inclusion of non-DSM symptoms associated with MDD.
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Title: TASK-BASED LOAD FORECASTING AND ROBUST RESOURCE SCHEDULING IN SMART GRID
Creator: Han, Jiayu
Date: 2021
Description: In microgrids, the uncertainty of load and renewables and lack of generation capacity will lead to a wide variety of operation problems in...
Show moreIn microgrids, the uncertainty of load and renewables and lack of generation capacity will lead to a wide variety of operation problems in both grid-connected mode and islanded mode. This motivates the design of the state-of-art microgrid master controller for microgrid energy management, load forecasting, and demand response. Uncertainty in renewables and load is a great challenge for microgrid operation, especially in islanded mode as the microgrid may be small in size and has limited flexible resources. A multi-timescale, two-stage robust dispatch model is proposed to optimize the microgrid operation. The proposed one uses only one model to combine the hourly and sub-hourly dispatch together, which means the day-ahead hourly dispatch results must also satisfy the sub-hourly conditions. At the same time, the feasibility of the day-ahead dispatch result is verified in the worst-case condition considering the high-level uncertainty in renewable energy output and load consumptions. In addition, battery energy storage system (BESS) and solar PV units are integrated as a combined solar-storage system in the proposed model and the output power of the combined solar-storage system remains unchanged on an hourly basis. Furthermore, both BESS and thermal units provide regulating reserve to manage solar and load uncertainty. The model has been tested in a controller hardware in loop (CHIL) environment for the Bronzeville Community Microgrid system in Chicago. The simulation results show that the proposed model works effectively in managing the uncertainty in solar PV and load and can provide a flexible dispatch in both grid-connected and islanded modes.When the generation capacity of an islanded microgrid is less than the load demand, load curtailment is inevitable. This dissertation proposes a multi-objective optimization model to minimize the load curtailments. Specifically, the proposed model minimizes the generation cost and total load curtailments and also minimizes the maximum load curtailment. Furthermore, the impact of the penalty coefficients of total load curtailment and maximum load curtailment is analyzed, which provides a strategy to choose the value of the two penalty coefficients according to different practical purposes. The proposed model can be used in both microgrid generation scheduling and microgrid planning problems. It was tested in the Bronzeville Community Microgrid system and the results showed that the proposed model can reduce the total load curtailment and maximum load curtailment.Load forecasting is one of the most important and studied topics in modern power systems. However, traditional load forecasting is an open-loop process as it does not consider the end use of the forecasted load. This dissertation proposes a closed-loop task-based day-ahead load forecasting model labeled as LfEdNet that combines two individual layers in one model, including a load forecasting layer based on deep neural network (Lf layer) and a day-ahead stochastic economic dispatch (SED) layer (Ed layer). The training of LfEdNet aims to minimize the cost of the day-ahead SED in the Ed layer by updating the parameters of the Lf layer. Sequential quadratic programming (SQP) is used to solve the day-ahead SED in the Ed layer. The test results demonstrate that the forecasted results produced by LfEdNet can lead to lower cost of day-ahead SED at the expense of slight reduction in forecasting accuracy.
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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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