2,274 research outputs found

    Axially-loaded centrifuge pile tests

    Get PDF
    This report concerns investigations of the behavior of piles under axial loading using centrifugal modeling and t-z analysis. The results of five centrifuge model pile tests on instrumented piles are presented. The present chapter puts this work into perspective, both with relation to current practical concerns with pile performance and existing analytical techniques

    Comparison of three separate one-step soft contact lens solutions in relation to patient sensitivity

    Get PDF
    Three new contact lens solutions have recently been approved by the FDA for one-step disinfection of soft contact lenses: Alcon\u27s Opti-OneTM, Allergan\u27s COMPLETE®, and Ciba\u27s Quick CARE™. These solutions are indicated for use in the disinfection, daily cleaning, rinsing and storing of soft contact lenses. They are approved for direct placement on the eye with soft contact lenses. This investigation compared the relationship between the three solutions and subjective ocular comfort/sensitivity. Ninety subjects participated in one of three experimental sessions to compare the ophthalmic solutions. Ratings for ocular surface sensitivity to OptiOneTM, Quick CARE™, and COMPLETE®, demonstrated no statistically significant change from pre-instillation to post-instillation conditions. In addition, there was no consistent pattern of preference for one solution over another. In fact, in direct comparison of solutions, over forty percent of subjects reported no difference in ocular comfort

    Using Electrochemical Oxidation to Remove PFAS in Simulated Investigation-DerivedWaste (IDW): Laboratory and Pilot-Scale Experiments

    Get PDF
    Repeated use of aqueous firefighting foams at military aircraft training centers has contaminated groundwater with per and polyfluorinated alkyl substances (PFAS). To delineate the extent of PFAS contamination, numerous site investigations have occurred, which have generated large quantities of investigation-derived wastes (IDW). The commonly used treatment of incinerating PFAS-tainted IDW is costly, and was recently suspended by the Department of Defense. Given long-term IDW storage in warehouses is not sustainable, our objective was to use electrochemical oxidation to degrade PFAS in contaminated water and then scale the technology toward IDW treatment. This was accomplished by conducting a series of laboratory and pilot-scale experiments that electrochemically oxidized PFAS using direct current with boron-doped diamond (BDD) electrodes. To improve destruction efficiency, and understand factors influencing degradation rates, we quantified the treatment effects of current density, pH, electrolyte and PFAS chain length. By using 14C-labeled perfluorooctanoic acid (PFOA) and tracking temporal changes in both 14C-activity and fluoride concentrations, we showed that oxidation of the carboxylic head (-14COOH ! 14CO2) was possible and up to 60% of the bonded fluorine was released into solution. We also reported the efficacy of a low-cost, 3D printed, four-electrode BDD reactor that was used to treat 189 L of PFOA and PFOS-contaminated water (Co ≤ 10 µg L-1). Temporal monitoring of PFAS with LC/MS/MS in this pilot study showed that PFOS concentrations decreased from 9.62 µg L-1 to non-detectable (\u3c0.05 µg L-1) while PFOA dropped from a concentration of 8.16 to 0.114 µg L-1. Efforts to improve reaction kinetics are ongoing, but current laboratory and pilot-scale results support electrochemical oxidation with BDD electrodes as a potential treatment for PFAS-tainted IDW

    Downregulation of HLA Class I Renders Inflammatory Neutrophils More Susceptible to NK Cell-Induced Apoptosis

    Get PDF
    Neutrophils are potent effector cells and contain a battery of harmful substances and degrading enzymes. A silent neutrophil death, i.e., apoptosis, is therefore of importance to avoid damage to the surrounding tissue and to enable termination of the acute inflammatory process. There is a pile of evidence supporting the role for pro-inflammatory cytokines in extending the life-span of neutrophils, but relatively few studies have been devoted to mechanisms actively driving apoptosis induction in neutrophils. We have previously demonstrated that natural killer (NK) cells can promote apoptosis in healthy neutrophils. In this study, we set out to investigate how neutrophil sensitivity to NK cell-mediated cytotoxicity is regulated under inflammatory conditions. Using in vitro-activated neutrophils and a human skin chamber model that allowed collection of in vivo-transmigrated neutrophils, we performed a comprehensive characterization of neutrophil expression of ligands to NK cell receptors. These studies revealed a dramatic downregulation of HLA class I molecules in inflammatory neutrophils, which was associated with an enhanced susceptibility to NK cell cytotoxicity. Collectively, our data shed light on the complex regulation of interactions between NK cells and neutrophils during an inflammatory response and provide further support for a role of NK cells in the resolution phase of inflammation

    Assessment of Dose-dependent Endocrine and Immune Responses to Simulated Ionizing Radiation

    Get PDF
    The hypothalamic-pituitary-adrenal axis can regulate immune responses to counteract stressful stimuli in maintaining homeostasis within the body. Cosmic ionizing radiation is an innate risk within the space environment and it is known to cause direct DNA damage and indirectly impact cellular function, transduction, and communication processes. Assessment of different physiological systems and their interactions are important to consider for mitigation strategies in spaceflight. The degree of ionizing radiation and relative biological effectiveness is an open question as it pertains to immune and endocrine responses. Therefore, this study will assess the dose-dependent responses of immunity and adrenal function to cosmic ionizing radiation. For this, male and female C57 BL/6J mice were exposed to simulated, simplified five-ion galactic cosmic ray (GCR) radiation at 5cGy, 15cGy, and 50cGy. Blood and tissues were collected two-weeks post exposure and inflammatory biomarkers and hormone biochemical pathways were characterized by whole transcriptome RNA sequencing. Results displayed differential transcriptomic profiles for each condition and sex, indicating complex responses and networks are generated from different doses of ionizing radiation. Careful consideration of unique profiles highlights the current need for personalized medicine requirements for astronauts exposed to similar doses on exploration missions. Supported by the NASA Human Research Program (HRP) Human Factors Behavioral Performance Element Grant 18 18FLAG 2 0028 and Embry-Riddle Aeronautical University startup funding

    Search for CP violation at CLEO

    Get PDF
    Recent results from CLEO on the search for CP violation in beauty and charm meson decays are reviewed.Comment: 7 pages, 5 figures, contribution to the proceedings of CPconf 2000, International Conference On CP Violation Physics, September 18-22, 2000, Ferrara, ITALY. Replacement version with typos and grammar correction

    Heat to Electricity Conversion by a Graphene Stripe with Heavy Chiral Fermions

    Full text link
    A conversion of thermal energy into electricity is considered in the electrically polarized graphene stripes with zigzag edges where the heavy chiral fermion (HCF) states are formed. The stripes are characterized by a high electric conductance Ge and by a significant Seebeck coefficient S. The electric current in the stripes is induced due to a non-equilibrium thermal injection of "hot" electrons. This thermoelectric generation process might be utilized for building of thermoelectric generators with an exceptionally high figure of merit Z{\delta}T \simeq 100 >> 1 and with an appreciable electric power densities \sim 1 MW/cm2.Comment: 8 pages, 3 figure
    • …
    corecore