Training Graduate Students in Utilization of Analytical Instruments in a Failure Analysis Course

Department of Engineering Technology at University of North Texas offers a graduate course on failure analysis (MSET 5150) during spring semesters. Partial requirement for the course is for students to submit a term paper based on their collected data related to a term project. Case studies are given to groups of students to work on actual failed components received from area industries. Results of their findings are presented at the end of the semester in both oral presentation form and written term paper form followed the format of a well-established technical papers. Results of such exercises allows graduate students devote skills in using scientific instruments and practice manuscript preparations for publication. This paper presents examples of a case studies done by groups of students who worked on failure analysis of components failed in an oil and gas industry. Students developed skills in utilization of scanning electron microscope (SEM), Energy Dispersive Spectroscopy (EDS), and Fourier Transform Infrared Spectrophotometry. This exercise has proven highly effective in introducing young engineers to real world problems in oil and gas industry and help them develop skills needed in performing failure analysis and steps involved.Cockrell School of Engineerin

Measurement of the Coefficient of Thermal Expansion of Superconducting Thin Films Using Powder X-Ray Diffraction

The High Density Electronics Center (HiDEC) at the University of Arkansas, Fayetteville is developing the technology for High Temperature Superconductor Multi-Chip Modules (HTSC-MCM\u27s). As part of this work, we are looking at the mechanical properties of HTSC materials. An important mechanical property which influences the mechanical integrity of the hybrid MCMis the coefficient of thermal expansion (CTE) of the HTSC films. As a first step in developing a procedure for the determination of the CTE of HTSC materials, the lattice parameters and the CTE of an alpha-alumina substrate have been determined by powder x-ray diffraction technique. An extension of this technique applicable to HTSC materials is presented

Hotspot ESR1 mutations are multimodal and contextual modulators of breast cancer metastasis

Constitutively active estrogen receptor α (ER/ESR1) mutations have been identified in approximately one-third of ER+ metastatic breast cancers. Although these mutations are known as mediators of endocrine resistance, their potential role in promoting metastatic disease has not yet been mechanistically addressed. In this study, we show the presence of ESR1 mutations exclusively in distant but not local recurrences in five independent breast cancer cohorts. In concordance with transcriptomic profiling of ESR1-mutant tumors, genome-edited ESR1 Y537S and D538G-mutant cell models exhibited a reprogrammed cell adhesive gene network via alterations in desmosome/gap junction genes and the TIMP3/MMP axis, which functionally conferred enhanced cell–cell contacts while decreasing cell-extracellular matrix adhesion. In vivo studies showed ESR1-mutant cells were associated with larger multicellular circulating tumor cell (CTC) clusters with increased compactness compared with ESR1 wild-type CTCs. These preclinical findings translated to clinical observations, where CTC clusters were enriched in patients with ESR1-mutated metastatic breast cancer. Conversely, context-dependent migratory phenotypes revealed cotargeting of Wnt and ER as a vulnerability in a D538G cell model. Mechanistically, mutant ESR1 exhibited noncanonical regulation of several metastatic pathways, including secondary transcriptional regulation and de novo FOXA1-driven chromatin remodeling. Collectively, these data provide evidence for ESR1 mutation–modulated metastasis and suggest future therapeutic strategies for targeting ESR1-mutant breast cancer

Polymer Derived Heteroatom Doped Porous Carbon Materials

Heteroatom doped porous carbon materials HPCMs have found extensive applications in adsorption separation, organic catalysis, sensing, and energy conversion storage. The judicious choice of carbon precursors is crucial for the manufacture of HPCMs with specific usages and maximization of their functions. In this regard, polymers as precursors have demonstrated great promise because of their versatile molecular and nanoscale structures, modulatable chemical composition, and rich processing techniques to generate textures that, in combination with proper solid state chemistry, can be maintained throughout carbonization. This Review comprehensively surveys the progress in polymer derived functional HPCMs in terms of how to produce and control their porosities, heteroatom doping effects, and morphologies and their related use. First, we summarize and discuss synthetic approaches, including hard and soft templating methods as well as direct synthesis strategies employing polymers to control the pores and or heteroatoms in HPCMs. Second, we summarize the heteroatom doping effects on the thermal stability, electronic and optical properties, and surface chemistry of HPCMs. Specifically, the heteroatom doping effect, which involves both single type heteroatom doping and codoping of two or more types of heteroatoms into the carbon network, is discussed. Considering the significance of the morphologies of HPCMs in their application spectrum, potential choices of suitable polymeric precursors and strategies to precisely regulate the morphologies of HPCMs are presented. Finally, we provide our perspective on how to predefine the structures of HPCMs by using polymers to realize their potential applications in the current fields of energy generation conversion and environmental remediation. We believe that these analyses and deductions are valuable for a systematic understanding of polymer derived carbon materials and will serve as a source of inspiration for the design of future HPCM

Refractive accuracy and visual outcome by self-refraction using adjustable-focus spectacles in young children. A randomized clinical trial

IMPORTANCE: Uncorrected refractive error is the most common cause of vision impairment in children. Most children 12 years or older can achieve visual acuity (VA) of 20/25 or better by self-refraction using adjustable-focus spectacles, but data on younger children are lacking. OBJECTIVE: To assess refractive accuracy, corrected VA, and factors associated with not achieving VA of 20/25 or better among children aged 5 to 11 years performing self-refraction with Adspecs adjustable-focus spectacles (Adaptive Eyecare), compared with noncycloplegic autorefraction and cycloplegic refraction. DESIGN, SETTING, AND PARTICIPANTS: This was a cross-sectional noninferiority trial conducted from September 2, 2015, to December 14, 2017. The study setting was an academic pediatric eye clinic. Children aged 5 to 11 years with uncorrected VA of 20/40 or worse in 1 or both eyes and without systemic or ocular conditions preventing best-corrected VA of 20/25 or better were enrolled. Children who had best-corrected VA worse than 20/25 were excluded. Study data were analyzed from September 2017 to June 2023. EXPOSURES: Children were taught to self-refract with adjustable-focus spectacles. MAIN OUTCOMES AND MEASURES: Spherical equivalent refractive error (using self-refraction, noncycloplegic autorefraction, and cycloplegic refraction) and VA (uncorrected and using self-refraction, noncycloplegic autorefraction, and cycloplegic refraction) for study eyes were evaluated. Potential predictors of failure to achieve VA of 20/25 or better with self-refraction were assessed using logistic regression. RESULTS: A total of 127 consecutive children were enrolled. After exclusions, 112 children (median [IQR] age, 9.0 [8.0-10.3] years; 52 boys [46.4%]) were included in the study. Mean (SD) spherical equivalent refractive power was -2.00 (1.52) diopters (D) for self-refraction, -2.32 (1.43) D for noncycloplegic autorefraction, and -1.67 (1.49) D for cycloplegic refraction. Mean (SD) difference in refractive power between self-refraction and noncycloplegic autorefraction was 0.32 (1.11) D (97.5% 1-sided CI, 0.11 to ∞ D; P  .99). Those failing to achieve best-corrected VA of 20/25 or better with self-refraction had higher astigmatism (odds ratio [OR], 10.6; 95% CI, 3.1-36.4; P < .001) and younger age (OR, 1.5; 95% CI, 1.1-2.2; P = .02). CONCLUSIONS AND RELEVANCE: Self-refraction among children aged 5 to 11 years may result in more myopic power than cycloplegic refraction but not necessarily to a clinically relevant degree. Although the proportion of children achieving VA of 20/25 or better with self-refraction using adjustable-focus spectacles did not differ from cycloplegic refraction, it was less likely among younger children and those with higher astigmatism