Uncertainty Analysis of Experimental Discharge Coefficients in Additively Manufactured Liquid Injector Elements

Screening of two additively manufactured liquid injector designs was conducted in the UAH high pressure spray facility. Four variants of each geometry with slightly different dimensions were obtained from eleven separate commercial additive manufacturing services. The devices were manufactured from Inconel 625 using the selective laser melting (SLM) powder bed process. The devices were cold flowed with water over a range of relevant pressure drops (75 psi to 1500 psi) to produce water flow rates from 0.037 to 1.75 lbm/s into ambient back pressure. Discharge coefficients determined from the testing along with the associated uncertainties provide insight into characteristic flow performance variabilities that can be expected from the SLM process for similar geometries

Age-Based Dynamics of a Stable Circulating Cd8 T Cell Repertoire Component

T-cell memory to pathogens can be envisioned as a receptor-based imprint of the pathogenic environment on the naive repertoire of clonotypes. Recurrent exposures to a pathogen inform and reinforce memory, leading to a mature state. The complexity and temporal stability of this system in man is only beginning to be adequately described. We have been using a rank-frequency approach for quantitative analysis of CD8 T cell repertoires. Rank acts as a proxy for previous expansion, and rank-frequency, the number of clonotypes at a particular rank, as a proxy for abundance, with the relation of the two estimating the diversity of the system. Previous analyses of circulating antigen-experienced cytotoxic CD8 T-cell repertoires from adults have shown a complex two-component clonotype distribution. Here we show this is also the case for circulating CD8 T cells expressing the BV19 receptor chain from five adult subjects. When the repertoire characteristic of clonotype stability is added to the analysis, an inverse correlation between clonotype rank frequency and stability is observed. Clonotypes making up the second distributional component are stable; indicating that the circulation can be a depot of selected clonotypes. Temporal repertoire dynamics was further examined for influenza-specific T cells from children, middle-aged, and older adults. Taken together, these analyses describe a dynamic process of system development and aging, with increasing distributional complexity, leading to a stable circulating component, followed by loss of both complexity and stability

Uncertainty Analysis of Experimental Discharge Coefficients in Additively Manufactured Liquid Injector Elements

No abstract availabl

Current method of high level disinfection (HLD) of duodenoscopes appears to prevent Carbapenem-resistant Enterococcal (CRE) colonization and transmission: a QI project

Conclusion: HLD appears to eliminate the risk of colonization and transmission of CRE. Periodic cultures of the elevator tip and the scope tip might be a cost effective way to monitor for potential CRE contamination and risk of transmission. Larger data from other centers might be useful to validate the protocol used in this study

Stakeholder Perspectives on the School Experiences of Students With Traumatic Brain Injury: The Effects of COVID-19 Pandemic on Service Delivery

Background: For students with traumatic brain injury (TBI), the COVID-19 pandemic exacerbated challenges they were already experiencing at school. Methods: This qualitative study employed focus groups and interviews with students, parents, school, and medical personnel to explore the school experiences of students with TBI. Thematic qualitative analyses were used. Results:Key themes from the analysis include (a) incidence of brain injuries decreased; (b) screen time for students with TBI exacerbated symptoms; (c) COVID protocols at school made it difficult for educators to identify and provide accommodations for students with TBI; (d) COVID protocols at school could inadvertently exacerbate mental health difficulties after a TBI; and (e) COVID-related logistics increased the time between an injury and return to school or return to play. Implications for School Health Policy, Practice, and Equity: The results from this study suggest that professional development for teachers supporting students with TBI is needed, especially for online learning environments. Additionally, because mental/behavioral health concerns may arise for students with TBI in online learning environments, school health care providers can work with families to assess a student\u27s mental health, making referrals to appropriate supports. Conclusions There is a significant need for professional development and school-wide infrastructure supportive of students with TBI

Synthesis and Structural Characterization of Heterometallic Thorium Aluminum Polynuclear Molecular Clusters

Aluminum can undergo hydrolysis in aqueous solutions leading to the formation of soluble molecular clusters, including polynuclear species that range from 1 to 2 nm in diameter. While the behavior of aluminum has been extensively investigated, much less is known about the hydrolysis of more complex mixed-metal systems. This study focuses on the structural characteristics of heterometallic thorium–aluminum molecular species that may have important implications for the speciation of tetravalent actinides in radioactive waste streams and environmental systems. Two mixed metal (Th⁴⁺/Al³⁺) polynuclear species have been synthesized under ambient conditions and structurally characterized by single-crystal X-ray diffraction. [Th₂Al₆(OH)₁₄(H₂O)₁₂(hedta)₂]­(NO₃)₆(H₂O)₁₂ (<b>ThAl1</b>) crystallizes in space group <i>P</i>2₁/<i>c</i> with unit cell parameters of <i>a</i> = 11.198(1) Å, <i>b</i> = 14.210(2) Å, <i>c</i> = 23.115(3) Å, and β = 96.375° and [Th₂Al₈(OH)₁₂(H₂O)₁₀(hdpta)₄]­(H₂O)₂₁ (<b>ThAl2</b>) was modeled in <i>P</i>1̅ with <i>a</i> = 13.136(4) Å, <i>b</i> = 14.481(4) Å, <i>c</i> = 15.819(4) Å, α = 78.480(9)°, β = 65.666(8)°, γ = 78.272(8)°. Infrared spectra were collected on both compounds, confirming complexation of the ligand to the metal center, and thermogravimetric analysis indicated that the thermal degradation of these compounds resulted in the formation of an amorphous product at high temperatures. These mixed metal species have topological relationships to previously characterized aluminum-based polynuclear species and may provide insights into the adsorption of tetravalent actinides on colloidal or mineral surfaces

Synthesis and Structural Characterization of Heterometallic Thorium Aluminum Polynuclear Molecular Clusters

Aluminum can undergo hydrolysis in aqueous solutions leading to the formation of soluble molecular clusters, including polynuclear species that range from 1 to 2 nm in diameter. While the behavior of aluminum has been extensively investigated, much less is known about the hydrolysis of more complex mixed-metal systems. This study focuses on the structural characteristics of heterometallic thorium–aluminum molecular species that may have important implications for the speciation of tetravalent actinides in radioactive waste streams and environmental systems. Two mixed metal (Th⁴⁺/Al³⁺) polynuclear species have been synthesized under ambient conditions and structurally characterized by single-crystal X-ray diffraction. [Th₂Al₆(OH)₁₄(H₂O)₁₂(hedta)₂]­(NO₃)₆(H₂O)₁₂ (<b>ThAl1</b>) crystallizes in space group <i>P</i>2₁/<i>c</i> with unit cell parameters of <i>a</i> = 11.198(1) Å, <i>b</i> = 14.210(2) Å, <i>c</i> = 23.115(3) Å, and β = 96.375° and [Th₂Al₈(OH)₁₂(H₂O)₁₀(hdpta)₄]­(H₂O)₂₁ (<b>ThAl2</b>) was modeled in <i>P</i>1̅ with <i>a</i> = 13.136(4) Å, <i>b</i> = 14.481(4) Å, <i>c</i> = 15.819(4) Å, α = 78.480(9)°, β = 65.666(8)°, γ = 78.272(8)°. Infrared spectra were collected on both compounds, confirming complexation of the ligand to the metal center, and thermogravimetric analysis indicated that the thermal degradation of these compounds resulted in the formation of an amorphous product at high temperatures. These mixed metal species have topological relationships to previously characterized aluminum-based polynuclear species and may provide insights into the adsorption of tetravalent actinides on colloidal or mineral surfaces