26 research outputs found
Flame-made Alumina Supported Pd-Pt Nanoparticles: StructuralProperties and Catalytic Behavior in Methane Combustion
Bimetallic palladium-platinum nanoparticles supported on alumina were prepared by flame spray pyrolysis. The as-prepared materials were characterized by scanning transmission electron microscopy (STEM), CO chemisorption, nitrogen adsorption (BET), X-ray diffraction (XRD), temperature programmed reduction (TPR), thermogravimetric analysis (TGA) and extended X-ray absorption fine structure (EXAFS) spectroscopy. The materials were tested for the catalytic combustion of methane with a focus on the thermal stability of the noble metal particles. After flame synthesis the noble metal components of the materials were predominantly in oxidized state and finely dispersed on the alumina matrix. Reduction afforded small bimetallic Pd-Pt alloy particles (< 5nm) supported on Al2O3 ceramic nanoparticles. The addition of small amounts of platinum made the palladium particles more resistant against sintering at high temperatures and further lowered the deactivation observed during methane combustio
Use of a novel pressure distribution system for severely ill neonates: a clinical pilot study carried out by the PREPICare consortium
Background: Pressure Injuries are not exclusively an adult phenomenon; various risk factors contribute to a high prevalence rate of 43% in the neonatal and pediatric intensive care population. Effective preventive measures in this population are limited.
Methods: We performed a pilot study to analyze the distribution and localization of support surface interface pressures in neonates in a pediatric intensive care unit (PICU). The hypothesis was that pressure redistribution by a novel air mattress would reduce pressure peaks in critical neonates. The measurements were conducted in a 27-bed level III PICU between November and December 2020. This included measuring pressure distribution and pressure peaks for five neonates positioned on either a state-of-the-art foam mattress or a new prototype air mattress.
Results: We confirmed that the pressure peaks were significantly reduced using the prototype air mattress, compared with the state-of-the-art foam mattress. The reduction of mean pressure values was 9-29%, while the reduction of the highest 10% of pressure values was 23-41%.
Conclusions: The journey to an effective, optimal, and approved product for severely ill neonates to reduce Pressure Injuries is challenging. However, a crucial step was completed by this pilot study with the first pressure measurements in a real-world setting and the successful realization of a decrease in pressure peaks obtained using a prototype air mattress
Meeting Report: ESC Forum on Drug Eluting Stents European Heart House, Nice, 27-28 September 2007
Flame aerosol deposition of Y2O3:Eu nanophosphor screens and their photoluminescent performance
Screens of Y2O3:Eu3 +-nanophosphor (d BET = 24nm) with coating densities in the range 0.23-3.8 mgcm - 2 were obtained by flame aerosol deposition (FAD) from nitrate-based precursors. The average deposition rate was 0.22 mgcm - 2min- 1. Porosity of the obtained deposits was 0.973 ± 0.004. Light scattering of the coatings in the visible range showed a Rayleigh-like dependence on wavelength and, in comparison to the screens made of the commercial micrometer-sized phosphor powder (dSEM = 4μm), was reduced by up to two orders of magnitude. As a result, the nanophosphor coatings maintained nearly constant brightness in a very wide range of coating densities. Furthermore, it should be expected that a substantially improved screen resolution can be achieved with such screens. For excitation at a wavelength of 254nm, the maximum brightness of the FAD-deposited (Y 0.92Eu0.08)2O3 phosphor screens in the transmission mode was nearly one third of that of the screens made of the commercial phosphor. It was demonstrated that light reflection from the supporting substrate and porosity of the coating significantly influence its photoluminescent performance
Flame aerosol deposition of Y2O3:Eu nanophosphor screens and their photoluminescent performance
Screens of Y2O3:Eu3 + -nanophosphor (dBET = 24 nm) with coating densities in the range 0.23–3.8 mg cm − 2 were obtained by flame aerosol deposition (FAD) from nitrate-based precursors. The average deposition rate was 0.22 mg cm − 2 min − 1. Porosity of the obtained deposits was 0.973 ± 0.004. Light scattering of the coatings in the visible range showed a Rayleigh-like dependence on wavelength and, in comparison to the screens made of the commercial micrometer-sized phosphor powder (dSEM = 4 µm), was reduced by up to two orders of magnitude. As a result, the nanophosphor coatings maintained nearly constant brightness in a very wide range of coating densities. Furthermore, it should be expected that a substantially improved screen resolution can be achieved with such screens. For excitation at a wavelength of 254 nm, the maximum brightness of the FAD-deposited (Y0.92Eu0.08)2O3 phosphor screens in the transmission mode was nearly one third of that of the screens made of the commercial phosphor. It was demonstrated that light reflection from the supporting substrate and porosity of the coating significantly influence its photoluminescent performance.ISSN:1367-263
Flame-made Alumina Supported Pd–Pt Nanoparticles: Structural Properties and Catalytic Behavior in Methane Combustion
ISSN:1011-372XISSN:1572-879
Use of a novel pressure distribution system for severely ill neonates: a clinical pilot study carried out by the PREPICare consortium
Abstract Background Pressure Injuries are not exclusively an adult phenomenon; various risk factors contribute to a high prevalence rate of 43% in the neonatal and pediatric intensive care population. Effective preventive measures in this population are limited. Methods We performed a pilot study to analyze the distribution and localization of support surface interface pressures in neonates in a pediatric intensive care unit (PICU). The hypothesis was that pressure redistribution by a novel air mattress would reduce pressure peaks in critical neonates. The measurements were conducted in a 27-bed level III PICU between November and December 2020. This included measuring pressure distribution and pressure peaks for five neonates positioned on either a state-of-the-art foam mattress or a new prototype air mattress. Results We confirmed that the pressure peaks were significantly reduced using the prototype air mattress, compared with the state-of-the-art foam mattress. The reduction of mean pressure values was 9–29%, while the reduction of the highest 10% of pressure values was 23–41%. Conclusions The journey to an effective, optimal, and approved product for severely ill neonates to reduce Pressure Injuries is challenging. However, a crucial step was completed by this pilot study with the first pressure measurements in a real-world setting and the successful realization of a decrease in pressure peaks obtained using a prototype air mattress
Development of a Textile Integrated, Two-State Controlled Tremor Suppression Orthosis for the Wrist
Tremor is one of the most common movement disorders with the highest prevalence in the upper limb. Apart from medication or surgery, the mechanical suppression of the involuntary movement with an orthosis can be used as alternative treatment. Here we propose a controlled energy dissipating suppression orthosis using a mechanical brake. For this approach, we focused on improved wearability with voluntary movement preservation and ergonomics while providing tremor suppression. The novelty of this orthosis is the decentralization of the tremor suppression mechanism and the integration of textiles in the orthosis structure. We performed computational and test bench simulations of a controlled two-state brake with a 1D human model to optimize the brake duration and timing. The objective was to optimize the trade-off between tremor suppression and voluntary movement suppression. The textile-integrated prototype, with the optimized parameter, was validated in a proof-of-concept case study with a tremor-affected person performing activities of daily living. With the optimized parameters, we achieved a tremor suppression of 78.8%, 66.5%, and 40.8% for the simulation, test bench, and case study, respectively as measured by the change in power spectral density (PSD) at the tremor frequency peak. While minimizing the voluntary movement suppression in the simulation and test bench by introducing the trajectory distance as new validation method (23.7% and 31.2%), no voluntary movements suppression was measured in the case study using PSD analysis. Our new orthosis has the potential to become a daily wearable device that can improve the quality of life for tremor-affected people.ISSN:2576-320