Numerical solution of heat conduction problems with a change of phase

Numerical solutions for the freezing of finite slabs, cylinders, and spheres initially above the fusion temperature subject to boundary conditions of the first, second, and third kind were obtained by utilizing the DuFort-Frankel finite-difference scheme. Illustrative calculations for the transient temperature field, freezing front location, heat flux at the wall, and times for complete freezing were presented for various values of the dimensionless parameters. The ranges of values for the dimensionless parameters for which solutions can be successfully obtained were determined. FORTRAN IV computer programs which can be used to obtain solutions for any conditions within these ranges have been made available. The computer programs were written in such a way as to be easily extended and/or modified to solve other freezing problems

A Vlasov-Poisson Numerical model for Multipactor Analysis

This thesis report describes a Vlasov-Poisson finite difference time domain numerical model that simulates parallel plate multipactor. The Vlassov approach which neglects collisions is well suited for sich analysis since the mutlipactor phenomenon occurs under near-vacuum collisionless conditions. Thus, electron transport can be modeled as the motion of a fluid subject to the influence of an external electromagnetic field. The advection of the electron swarm is determined by solving the Vlasov equation using a Koren flux limited numerical scheme. A direct Poisson solver accounts for space charge effects that become significant as electron growth occurs, hence a self-consistent Vlasov-Poisson combination. Bombarding electrons undergo secondary electron emission (SEE) with an energy-dependent secondary electron yield (SEY) at the spatial boundaries of the simulation. The model is able to simulate electron swarm dynamics from multipactor onset to well into the saturation regime. Specific analyses are performed on the time dependent physics that evolve within a multipacting system. Various orders of multipactor are compared to one another, and an analysis of the simulation parameters which alter multipactor saturation values is also discussed. This unique numerical model is meant to present an alternative way of simulating multipactor growth. Our results are compared to the predictions of SPARK 3D (a commercial software) and available experimental data, with good agreement in both cases

Some asymptotic results for functional lineal regression

We study the asymptotic behavior of the slop estimator in functional linear regression model with functional outputs. It turns out that expansions of analytic functions of covariance operator is a valuable tool in the theory of functional data. It this dissertation we apply this tool to obtain an upper bound for the integrated squared error (ISE) of the functional regression estimator for both random and fixed design. A lower bound is also discussed in this paper and obtained by van Trees inequality in the fixed design case. Our calculations are based on abstract Hilbert space, which generalizes the optimal rate provided in Hall and Horowitz (2007)

Open Educational Resource Advocacy: Examining Strategies and Resources for OER Supporters

It is not easy to bring an open educational resource (OER) into existence, but after all that work, creators are sometimes dismayed to find that their OER does not gain traction with their intended audience. Once the OER—be it a textbook or other material—is produced, what is next? How will other educators know that the newly composed OER exists, and why should they want to adopt it for their classrooms? The library can help. Three academic librarians successfully received an Affordable Learning Georgia Research Grant, the purpose of which was to conduct research on OER sustainability and advocacy. The grant team recruited a data analyst, and together they conducted a qualitative research study using an online survey instrument and received 98 responses from librarians and OER creators. Themes that emerged from the study include challenges (i.e. lack of time, energy, and support), communication and engagement (i.e., at events and other programming), and structured strategies (i.e., encouraging faculty and other creators to update their materials). Findings revealed that depositing into collections, making recommendations, and sharing via word of mouth and listservs are practical strategies and resources for OER creators and advocates. The article concludes with steps librarians and supporters can take to help OER creators design an advocacy plan and prioritize outreach.The research project and research team were funded through an ALG Affordable Materials Grant: Research Grants, Round 24, Grant RG008, to the amount of $10,000

Addition of Ticarcillin-Clavulanic Acid to INRA96 Extender in the Extension and Storage of Equine Semen: An Examination of its Effect on Semen Motion Characteristics and Viability

The use of stallion semen extenders containing antimicrobials is increasingly common in equine breeding facilities. Breeders now have numerous options for commercially available semen extenders for use in fresh, cooled semen. Commercially produced semen extenders, such as INRA 96®, commonly contain antimicrobials that may have limited efficacy. When this is a concern, many breeding facilities in the United States rely on the addition of ticarcillin-clavulanic acid to inhibit or eliminate possible bacterial growth. This practice, however, needs standardization from proven data. The focus of this study was on evaluating the effects of the addition of ticarcillin-clavulanic acid, Timentin®, to INRA 96. This included assessing the effect of different extender and antimicrobial storage conditions on sperm motion characteristics, sperm membrane integrity and antimicrobial effectiveness. Fourteen mature, actively breeding Quarter Horse stallions were collected and 42 gel-free semen ejaculates were diluted with INRA 96 extender and stored for 24 hours in Equitainer II units. Post storage evaluations consisted of sperm motion characteristics analysis by a computer-assisted analysis device, sperm membrane integrity evaluation by fluorescent measurements and bacterial isolation cultures for both aerobic and anaerobic bacteria. Data evaluation included analysis-of-variance and chi-square statistical methods with the P value for significance predetermined to < 0.05. Significant reduction in sperm motion characteristics, total motility, progressive motility and sperm membrane integrity, after 24 h of cooled storage were found in treatments that were subjected to freezing and thawing of modified or unmodified extender prior to use. The addition of reconstituted ticarcillin-clavulanic acid to the extender prior to use resulted in higher sperm velocity when treatments were exposed to cooled storage rather than frozen. Bacterial isolates were cultured from neat semen in only 28 of 42 ejaculates (67%). The addition of ticarcillin-clavulanic acid to INRA 96 was no different than the use of INRA 96 alone for the inhibition of bacterial growth (98% vs. 94%). The addition of ticarcillin-clavulanic acid at a dose rage of 1 mg/ml to INRA 96 extender did not negatively impact sperm motion characteristics and viability in extended semen after cooled storage. The act of freezing and thawing of extender prior to use did however have negative effects on sperm quality. This trial was conducted on a commercial breeding facility that did not have any cases of Pseudomonas aeruginosa or Klebsiella pneumoniae. Thus, additional studies are needed using samples that could be subjected to such pathogens. Results of this study suggest that INRA 96 extender should not be exposed to freezing and thawing prior to use. Bacterial cultures of the extender treatments indicated effective inhibition of bacterial growth when compared to neat semen

Boron nitride coatings for the enhanced detection of neutrons in CR-39

The neutron detection efficiency of Columbia Resin 39 (CR-39) nuclear track detectors was assessed for AmBe, 252Cf, and D-T (14 MeV) neutron source spectra. A boron nitride (BN) coating for CR-39 was developed to enhance the neutron detection efficiency by converting neutrons into energetic alpha particles through the well-known 10B (n,α)7Li reaction. Separate partially coated CR-39 pieces were exposed to each neutron source and subsequently analyzed under optical microscope and through large-area Scanning Electron Microscopy (SEM) imaging over the irradiated area. The detection efficiency (tracks per neutron) was evaluated for each source spectra under optical and scanning electron microscopes and with or without BN coating. This resulted in a comprehensive guide to neutron detection with various sources using CR-39.This work was supported by the Department of Energy award No. DE-AR0001736

Dual-impedance cardiography for the assessment of arterial stiffness: associations with blood pressure, cardiometabolic risk factors, and preclinical atherosclerosis in midlife adults

Purpose: Pulse wave velocity (PWV) is a measure of arterial stiffness that reflects vascular ageing and predicts risk for cardiovascular disease. We developed a PWV measurement method that uses dual-impedance cardiography (d-ICG) to address limitations of other common methods (e.g. ultrasound, tonometry, etc.), as well as to enable PWV assessments across a broader range of populations. This pre-registered, cross-sectional study tested for the first time the extent to which d-ICG PWV associates with cardiometabolic risk factors (i.e. blood pressure and other metabolic syndrome components) and vascular markers of preclinical atherosclerosis (i.e. carotid-artery intima-media thickness [C-IMT] and plaque). Methods: Participants were 366 healthy adults (aged 28–57; 63.4% female). In a subsample (N = 179), estimates of d-ICG PWV were compared for the first time against carotid-femoral PWV (cfPWV) measured by a Complior device. Results: d-ICG PWV and cfPWV measures were comparably associated with age and blood pressure (r’s ≥ .28, p’s ≤ .001), and they exhibited moderate consistency (ICCs = 0.51 to 0.55, p’s < .001). Across all cardiometabolic risk factors and markers of preclinical atherosclerosis, there were no clinically meaningful differences in the average composite (Fisher’s Z-score) correlations with arterial stiffness measured by d-ICG and cfPWV based on Cohen’s q values (q’s = 0.042 to 0.097). Conclusion: d-ICG PWV may be a low-cost, reliable, and alternative method for obtaining estimates of arterial stiffness that track with cardiometabolic risk factors and preclinical atherosclerosis.The research reported here was supported by the National Heart, Lung, and Blood Institute of the National Institutes of Health under grants [P01 HL040962 and R01 HL169990]. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health

Nurturing Green Hearts: The Relationship Between Connectedness to Nature, Well-Being, and Ecocentrism

Research has repeatedly shown that spending time in nature can provide mental and physical health benefits like stress and anxiety reduction. Building on such findings, our study attempts to demonstrate a cyclical human-nature relationship, arguing that high levels of connectedness and interconnectedness to nature promote higher levels of environmental concern and higher life satisfaction levels. A total of 106 U.S college students ranging from ages 18-24 were recruited through flyers, listservs, and snowball sampling. Participants completed our anonymous questionnaire via Qualtrics. The survey is a combination of four well-established scales used in both psychology and environmental psychology research: the Connectedness to Nature Scale (CNS), the New Ecological Paradigm (NEP) Scale, the Satisfaction with Life Scale (SWLS) and the Inclusion of Nature in Self (INS) Scale. These scales measure the four key variables in our study: belongingness to nature, environmental values, overall life satisfaction, and how much one chooses to include nature in one's life. In addition, we also gathered participants’ age, gender and major. We hypothesized that participants with stronger connection and interconnectedness with nature will also exhibit higher levels of life satisfaction and environmental concern. Our data analysis proved higher levels of life satisfaction amongst participants that choose to include nature in their lives but no significant correlation between any other variables. Future research can focus on cultivating a connection with nature in the youth to possibly ensure consistent mental health benefits while also exploring the foundation of ecological responsibility within generations. Hence, the title of our study, Nurturing Green Hearts: The Relationship Between Connectedness to Nature, Well-Being, and Ecocentrism

Architecture Library Reference Bibliography

The bibliography attached is related to Veeder’s research article, “Reimaging Reference and Permanent Reserve Collections: Dynamic Presentation and Pedagogical Foundations.” Physical titles held in the Architecture Library are listed as they appear upon the shelves, with the curriculum-based categories of the Huckabee College of Architecture undergraduate courses framing the sections. The ‘Architects’ and ‘TTU & Lubbock’ sections noted in the research are not listed here-within

Looking Backward Toward Progress: Re-evaluating Whiteness through Puritan Texts

This thesis takes a look back historically to link the Puritans’ ideological construction of whiteness to contemporary theoretical ideas of whiteness using Toni Morrison’s Playing in the Dark (1992) and Richard Dyer’s White (1997). The introduction begins with me detailing the theoretical frameworks that I’ll be applying to Puritan texts in order to show the legacy of whiteness. Through these theoretical frameworks, I discover that Puritans formed one foundation of the systemic racism which still exists in America today. This helps me uncover the racial and social injustice that American society has conveniently ignored. If Americans continue to ignore these habits that privilege whiteness, then these habits will continue to replicate themselves in the social, political, and economic spheres. I use whiteness as a lens to focus on the construction of a collective consciousness of white identity that John Cotton, Cotton Mather, John Winthrop, and Robert Cushman used to form communities and exclude others. Using Maryse Condé’s I, Tituba, the Black Witch, published in 1992, and Morrison’s A Mercy 2008, I read the novels in relation to a long tradition of black feminist thought, specifically, as outlined in Patricia Hill Collins’s Black Feminist Thought. These novels provide an insight into the psyche of colonial America and illuminate important questions regarding racialized legitimization, privilege, and transnational dimensions of slavery. Black women acquire a perspective that Collins calls the ‘outsider-within’ stance where black women are able to “have a distinct view of the contradictions between the dominant group’s actions and ideologies” (11). In effect, I am using Condé’s and Morrison’s novels to discuss issues of diasporic identity and memory that are important to the tradition of black feminist thought