Nuclear electric propulsion reactor control systems status

The thermionic reactor control system design studies conducted over the past several years for a nuclear electric propulsion system are described and summarized. The relevant reactor control system studies are discussed in qualitative terms, pointing out the significant advantages and disadvantages including the impact that the various control systems would have on the nuclear electric propulsion system design. A recommendation for the reference control system is made, and a program for future work leading to an engineering model is described

Loss of function of myosin chaperones triggers Hsf1-mediated transcriptional response in skeletal muscle cells

Quality of sequences obtained with CASAVA 1.8.1 (Illumina) workflow. PF reads passing Illumina chastity filter. (XLSX 46 kb

Symmetry Identified in 2-Dimensional Artwork Compositions Using Visuospatial Ability

At the John Langdon Down Foundation A.C. in the La Escuela Mexicana de Arte Down school in Mexico City D.F., Mexico, art students with Trisomy 21 display the use of a mathematical construct in the painting compositions of their artworks. The mathematical construct is a type of symmetry and it carries a positive affect. This is important because there have been no studies that have investigated the use of the symmetry in the artwork compositions of persons with Down syndrome. The geometric construction of the artwork compositions follows the artistic principle of the Rule of Three and the division of extreme and mean ratio (DEMR). The two specific geometric patterns are known as harmonic ratios and referred to as the HR-RT symmetry (harmonic ratio with Rule of Three) in this research. Painting composition is a demonstration of the intentionality of the artist, which involves sensory and cognitive processes that engage both artist and viewer. This communication is via the motoric ability of proportional gauging. The action of proportional gauging is the manner in which both the artist and viewer perceive the geometrics and aesthetics of the composition. This process is a conjoined visuospatial and bodily kinetic cortical process. A group of seven representative Master artists\u27 paintings from the Quattrocento was the standard of HR-RT with which to compare the use of the construct in the art students\u27 painting compositions. The Master artists\u27 employed HR-RT as a compositional element to direct the communication of a 3-dimensional spatial representation of an aesthetic experience via a 2-dimensional venue. A novel 5-step measurement procedure identifies the mathematical construct using a geometric grid overlay on the student artworks. In 159 student artworks (out of 161), the variable use of HR-RT, similar to the Master artists, was revealed in five quantized levels. The art students demonstrated the use of the construct at a strong level 62 images (38.51%) and at the moderate level 65 images (40.37%). Twenty-five of the images were at a low level (13.04%), 7 images were an inconsistent representation (4.347%) and in 2 images the construct was not found (1.24%)

Modern Survey Estimation with Social Media and Auxiliary Data

Traditional survey methods have been successful for nearly a century, but recently response rates have been declining and costs have been increasing, making the future of survey science uncertain. At the same time, new media sources are generating new forms of data, population data is increasingly readily available, and sophisticated machine learning algorithms are being created. This dissertation uses modern data sources and tools to improve survey estimates and advance the field of survey science. We begin by exploring the challenges of using data from new media, demonstrating how relationships between social media data and survey responses can appear deceptively strong. We examine a previously observed relationship between sentiment of ``jobs" tweets and consumer confidence, performing a sensitivity analysis on how sentiment of tweets is calculated and sorting ``jobs" tweets into categories based on their content, concluding that the original observed relationship was merely a chance occurrence. Next we track the relationship between sentiment of ``Trump" tweets and presidential approval. We develop a framework to interpret the strength of this observed relationship by implementing placebo analyses, in which we perform the same analysis but with tweets assumed to be unrelated to presidential approval, concluding that our observed relationship is not strong. Failing to find a meaningful signal, we next propose following a set of users over time. For a set of politically active users, we are able to find evidence of a political signal in terms of frequency and sentiment of their tweets around the 2016 presidential election. In a given corpus of tweets, there are likely to be several topics present, which has the potential to introduce bias when using the corpus to track survey responses. To help discover and sort tweets into these topics, we create a clustering-based topic modeling algorithm. Using the entire corpus, we create distances between words based on how often they appear together in the same tweet, create distances between tweets based on the distance between words in the tweets, and perform clustering on the resulting distances. We show that this method is effective using a validation set of tweets and apply it to the corpus of tweets from politically active users and ``jobs" tweets. Finally, we use population auxiliary data and machine learning algorithms to improve survey estimates. We develop an imputation-based estimation method that produces an unbiased estimate of the mean response of a finite population from a simple random sample when population auxiliary data are available. Our method allows for any prediction function or machine learning algorithm to be used to predict the response for out-of-sample observations, and is therefore able to accommodate a high dimensional setting and all covariate types. Exact unbiasedness is guaranteed by estimating the bias of the prediction function using subsamples of the original simple random sample. Importantly, the unbiasedness property does not depend on the accuracy of the imputation method. We apply this estimation method to simulated data, college tuition data, and the American Community Survey.PHDStatisticsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/163193/1/fergr_1.pd

Creativity Advances Logical, Spatial, and Aesthetics Cognitive Abilities Through Self-Reflection and May Improve Spatial Sequencing Memory

Creativity is defined as the ability to make new things or think of new ideas using multiple human aptitudes; it is inventiveness. Therefore, an important part of understanding creativity is through the self-reflection of your own cognitive components of logical, spatial and aesthetics thinking, which requires the cortical processes of spatial sequencing memory and affective symmetry gauging. Creativity is relevant to the global community and international education because it is an inherent human expression. A case study of the experience of the art teachers at the John Langdon Down Foundation A.C. (JLDF) Mexican art school (who chose to undergo a meaningful and emotional journey of self-reflection) is the account of the development of a novel visuospatial and bodily kinetic curriculum for the JLDF art students with Down syndrome that seemed to improve both the teachers’ and students’ creativity, self-efficacy and spatial sequencing memory

Using PXRD to Investigate the Crystallization of Highly Concentrated Emulsions of NH4NO3

The process of crystallization of highly concentrated emulsions of ammonium nitrate can be studied using powder X-ray diffraction. The dispersed particles comprise a supercooled aqueous solution of the ammonium nitrate salt and are dispersed in a paraffin-based oil. This results in a thermodynamically unstable system that ‘ages’ with time resulting in changes in rheological properties and its phase composition where the collapse of the supercooled aqueous solution forms the crystallized salt. The crystallization processes of these emulsions are kinetically slow and can take up to a few months to crystallize completely. The general approach to this type of analysis is to determine the change in crystalline diffraction peak intensities relative to the halo due to the amorphous content. However, there are a number of problems associated with this method which are addressed by using Rietveld refinement methods which can take into account factors such as preferred orientation, crystallite size variations and mixtures of solid phases. The study showed that the ammonium nitrate emulsions kept at room temperature slowly crystallize predominantly to the room temperature solid ammonium nitrate phase IV. However, depending on the formulations used some samples showed crystallization to the high temperature ammonium nitrate phase II before changing to phase IV. The crystallization change could be modelled by the well-known JMAK kinetic relationship.Keywords:  Ammonium nitrate emulsion, crystallinity, X-ray diffractio

The Use of an Experimental Design Approach to Investigate the Interactions of Additives used in the Making of the Negative Plate in Lead-acid Batteries

When a conventional starting, lighting and ignition (SLI) lead acid battery is exposed to a high rate partial state of charge (HRPSoC) cycling, it would experience a build-up of irreversible PbSO4 on the negative plate, resulting in capacity loss and electrode damage. The addition of certain graphites to the negative paste mix has proven to be successful in reducing this effect. This study looked at using statistical design of experimental (DoE) principles to observe interactions between two graphite types and a nanocarbon together with other additives, such as BaSO4 and Vanisperse, to a negative paste mixture. The response factors considered were in relation to their effect on the battery’s cold cranking ability (CCA) at –18 °C, the HRPSoC and its active material utilization. Typical flooded nominal 8 Ah test cells were assembled in a reverse ratio build,with three positive and two negative plates, with three types of added carbons (flake graphite, natural graphite and nanocarbon) added to the negative paste mixture at a two-level design. The study showed the usefulness of a statistical DoE approach in the effective use of additives that are included to the negative plate paste mixture, where there are interactions between the amounts of added carbon, BaSO4 and Vanisperse, with respect to the responses of CCA and HRPSoC, that do not necessarily act independently – based on their amounts – on the performance of the active material. The study also showed that there are correlations between certain response factors, such as the number of achievable cycles within a HRPSoC test sequence, and the type of added carbon.Keywords: Pb-acid battery, Pb-plate, graphite, expanders, design of experimen

Finite element modeling of the higher harmonic controlled OH-6A helicopter airframe

An MSC/NASTRAN finite element model of the higher harmonic control configured OH-6A helicopter fuselage was developed. This finite element model was verified by performing various model checkouts and correlation with results from a ground vibration test

Electrochemical Oxidation of Phenol using a Flow-through Micro-porous Lead Dioxide/Lead Cell

The electrochemical oxidation of phenol to benzoquinone followed by the reduction to hydroquinone and catechol was demonstrated by constructing a three-dimensional porous micro-flow cell from lead dioxideand lead. The electrodes were made by using the principles of curing and formation of lead oxide material that are common in the construction of the electrodes used in lead-acid batteries. This resulted in highly porous electrodes that can allow the reactant solution to flow through them in series, without the risk of having the products being oxidized again at the anode that usually occurs in a simple undivided cell. In this study, a 50 mM solution of phenol in a 60 % acetonitrile and water mixture was used that contained 2 % sulphuric acid. The reactantsolution would flow through the anode porous material oxidizing the phenol to benzoquinone. The benzoquinone in solution would then flow through the cathode porous material and reduce to catechol and hydroquinone. The study showed that almost all of the phenol could be converted in one continuous flow process in using a relatively low cost electrochemical micro-flow cell that can be easily scaled up to accommodate larger volumes and concentrations by using electrode manufacturing principles used in the lead-acid battery industry.Keywords: Phenol, hydroquinone, catechol, lead dioxide, micro-flow cel