Plasma assisted fabrication of zinc oxide based nanostructures

ZnO/Ag nanocomposite structures were prepared by using a discharge with an atmospheric-pressure mi-croplasma cathode and a solid metal anode immersed in an electrolyte solution and their properties were studied. The effect of Ag on the microstructure and optical properties of ZnO has been discussed

ПРИМЕНЕНИЕ ЛАЗЕРНОЙ АТОМНО-ЭМИССИОННОЙ СПЕКТРОСКОПИИ ДЛЯ АНАЛИЗА ЦЕМЕНТА

Laser-induced breakdown spectroscopy has been applied for a rapid determination of the main components in flooding cement. Spectra of the erosion plume formed under the action of dual laser pulses were recorded. We used the calibration-free approach based on the detailed diagnostic of the laser ablation plasma, without using standard samples of known composition. The accuracy of determining the basic elements for such an analytical approach was ~4 %.Лазерный атомно-эмиссионный спектральный анализ применен для экспрессного определения основных компонент заводненного цемента. Регистрировались спектры эрозионного факела, образованного под воздействием сдвоенных лазерных импульсов. В работе использовался безэталонный подход, основанный на детальной диагностике лазерной плазмы, исключающий калибровку по образцам с известным составом. Точность определения основных элементов для такого варианта анализа составила ~4 %

Computational Design of a Krueger Flap Targeting Conventional Slat Aerodynamics

In this study, we demonstrate the design of a Krueger flap as a substitute for a conventional slat in a high-lift system. This notional design, with the objective of matching equivalent-mission performance on aircraft approach, was required for a comparative aeroacoustic study with computational and experimental components. We generated a family of high-lift systems with Krueger flaps based on a set of design parameters. Then, we evaluated the high-lift systems using steady 2D RANS simulations to find a good match for the conventional slat, based on total lift coefficients in free-air. Finally, we evaluated the mean aerodynamics of the high-lift systems with Krueger flap and conventional slat as they were installed in an open-jet wind tunnel flow. The surface pressures predicted with the simulations agreed well with experimental results

The use of nanoparticles to improve the analytical capabilities of LIBS for solution sample analysis

Laser-induced breakdown spectroscopy (LIBS) is a diagnostic technique based on optical emission spectroscopy, suitable for rapid, in situ, and multi-element analysis of all sample types. LIBS has demonstrated its greatest potential in the analysis of solids, both conducting and nonconducting. However, when it comes to quantitative LIBS analysis of liquids, there are still some drawbacks that limit its applicability, such as poor repeatability and low sensitivity. To some extent LIBS performance may be improved if directly performing LIBS on the solution is avoided by converting the liquid into a solid phase. Another recently proposed method to resolve the difficulties in LIBS analysis of liquid samples is the application of Nanoparticle - Enhanced LIBS (NELIBS) [1,2]. The aim of the present work was to examine the effect of copper oxide nanoparticles (NPs) on the analytical capabilities of LIBS analysis of lead in aqueous solutions. The apparatus for NELIBS experiments comprises a laser source, a spectrograph (F=850 mm, grating 1800 groves/mm, F/11) coupled with a CCD, and the focusing and collecting optics, i.e. the same as used in conventional LIBS. A double pulse Q-switched Nd:YAG laser at 1064 nm, pulse duration 10 ns, pulse energy 50 mJ, interpulse delay 1 μs was used. The spectra were registered in a time-integrated mode (integration time 1 ms). A glass plate was chosen as the substrate to ensure there is no interference between NPs and the substrate. The first type of samples was prepared by drying a droplet of a Pb solution (10 μl, concentration 100 ppm) on the glass substrate. The second type was prepared by drying a droplet of the copper oxide colloidal solution on the glass, prior to the deposition of the analyte solution. Three sets of the LIBS spectra were acquired; spectra of glass with deposited CuO NPs, of glass with deposited sample solution of Pb, and of the glass with deposited NPs of CuO and the sample solution of Pb. The spectra were obtained in the 395-415 nm spectral range. Only in the third case, intense Pb lines appeared in the spectrum. Estimation of the limit of detection (LOD) for the resonance Pb line at 405.78 nm, without additional optimization of the measurement parameters, gave a value of 3.6 ppm. Regarding the fact that without the addition of the NPs layer no analyte signal was obtained, it can be concluded that the enhancement of the lead emission line intensity is caused by the presence of the NPs, i.e. by the lower plasma formation threshold and more efficient atomization of the analyte deposited on the NP layer. The main benefits of using NELIBS for the analysis of solutions lie in its simplicity, speed, the small amount of solution needed (few microliters), and the ability to analyze very dense or slurry samples.VII International School and Conference on Photonics : PHOTONICA2019 : Abstracts of Tutorial, Keynote, Invited Lectures, Progress Reports and Contributed Papers; August 26-30; Belgrad

International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

Comparison of two LIBS techniques for total carbon measurement in soils

The potentials of two advanced laser-induced breakdown spectroscopy (LIBS) techniques which are used to determine the total carbon content in soils have been examined. The first one is the combination of a single-pulse laser ablation with spark excitation of plasma plume triggering the gap between electrodes close to the target surface. The second one is a more conventional double-pulse LIBS. In both modes the calibration graphs have a nonlinear trend in the actual range of carbon contents and present a good R2 value (0.97). In the combined laser-spark approach, using low-cost and portable laser instrumentation is possible, as well as inducing a micro-damage on the target surface. Certain regularities in the spectral line intensities of soil nutritious elements have been detected and appear to be connected to the total carbon content and to the soil origin