52 research outputs found

    APPLICATION OF HYBRID DIBR-FUCOM-LMAW-BONFERRONI-GREY-EDAS MODEL IN MULTICRITERIA DECISION-MAKING

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    The selection of unmanned aerial vehicles for different purposes is a frequent topic of research. This paper presents a hybrid model of an unmanned aerial vehicle (UAV) selection using the Defining Interrelationships Between Ranked criteria (DIBR), Full Consistency Method (FUCOM), Logarithm Methodology of Additive Weights (LMAW) and grey - Evaluation based on Distance from Average Solution (G-EDAS) methods. The above-mentioned model is tested and confirmed in a case study. First of all, in the paper are defined the criteria conditioning the selection, and then with the help of experts and by applying the DIBR, FUCOM and LMAW methods, the weight coefficients of the criteria are determined. The final values of the weight coefficients are obtained by aggregating the values of the criteria weights from all the three methods using the Bonferroni aggregator. Ranking and selection of the optimal UAV from twenty-three defined alternatives is carried out using the G-EDAS method. Sensitivity analysis confirmed a high degree of consistency of the solutions obtained using other MCDM methods, as well as changing the criteria weight coefficients. The proposed model has proved to be stable; its application is also possible in other areas and it is a reliable tool for decision-makers during the selection process

    Structural Investigations of Polyvinyliden Fluoride Thin and Thick Films

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    Polyvinyliden fluoride (PVDF) is a low-density fluoropolymer that exhibits piezoelectric and pyroelectric properties. It can be used in the chemical, semiconductor, medical and defense industries, as well as in aviation and aerospace applications. Crucial factors that lead to the PVDF ferroelectric properties and determine its piezoelectric, mechanical, optical, electrical and thermal properties are its polar conformations, crystal structure, and crystallinity. These characteristics of the material significantly depend on the conditions used in the processing of polymer films. Therefore, we investigated structure and morphology of thin and thick PVDF films obtained by spin coating and solution casting methods, respectively. Structural investigations of PVDF thin and thick films were performed by the X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Fourier transform infrared spectrometry (FTIR) methods, while microstructure morphology has been analyzed by scanning electron microscope (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Present results will enable optimization of PVDF processing techniques for the production of pressure and IR sensors

    Formation and decay of the Rydberg states of multiply charged ions interacting with solid surfaces

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    Processes of formation and decay of the Rydberg states of multiply charged ions escaping solid surfaces with intermediate velocities (v approximate to 1 a.u.) represent complex quantum events that require a detailed quantum description. We have developed a two-state vector model for the population process, with the functions Psi(1) and Psi(2) for definition of the state of a single active electron. The electron exchange between the solid and the moving ion is described by a mixed flux through a plane positioned between them. For the low values of the angular momentum quantum numbers l the radial electronic coordinate rho can be neglected, whereas for the large-l values a wide space region around the projectile trajectory was taken into account. The reionization of the previously populated states is considered as a decay of the wave function Psi(2). The corresponding decay rates are obtained by an appropriate etalon equation method: in the large-l case the radial electronic coordinate rho is treated as a variational parameter. The theoretical predictions based on that population-reionization mechanism are compared with the available beam-foil experimental data, as well as the experimental data obtained in the interaction of multiply charged ions with micro-capillary foil. Generally, the model reproduces the experimentally observed non-linear trend of the l distributions from l = 0 to l(max) = n - 1.25th Summer School and International Symposium on the Physics of Ionized Gases - SPIG 2010, Aug 30-Sep 03, 2010, Donji Milanovac, Serbi

    Antioxidant biomarker profile of chironomid larvae from carp ponds: Evaluation of the effects of different fish feeding patterns

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    A 102-day feeding trial was conducted to evaluate the effects of four different fish feeding patterns on carp pond water quality and antioxidant biomarkers [superoxide dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GPx), Glutathione reductase (GR), Glutathione S-transferase (GST) and Thiol groups (SH)], protein content and biomass of the midge Chironomus plumosus. Farmed fish were fed two commercial diets: Soprofish 25/7 Standard (containing 25% protein and 7 % fat) and Soprofish 32/7 Profi Effect (containing 32 % protein and 7 % fat). These feeds were combined during a feeding trial in four different feeding patterns, designated as A, B, C and D. In feeding pattern A, the fish received Soprofish 25/7 Standard throughout the experiment and in feeding pattern D, Soprofish 32/7 Profi Effect. During feeding patterns B and C, a mixed feeding pattern was used, alternating between lower and higher protein diets. The study revealed no significant effects (P > 0.05) of the feeding regimens on water quality, so their effects on C. plumosus larvae can be evaluated independently. The activities of the chironomid enzymes CAT and GR showed a clear statistically significant dependence on the feeding pattern (P 0.05). Overall, our results suggest that long-term supplementation with a highly concentrated protein diet may have preventive effects against oxidative stress and support the use of C. plumosus as a model for assessing the effects of organic pollution on pond zoobenthic fauna. © 202

    RF IC performance optimization by synthesizing optimum inductors

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    Even with optimal system design and careful choice of topology for a particular RF application, large amounts of energy are often wasted due to low-quality passives, especially inductors. Inductors have traditionally been difficult to integrate due to their inherent low quality factors and modelling complexity. Furthermore, although many different inductor configurations are available for an RF designer to explore, support for integrated inductors in electronic design automation tools and process design kits has been very limited in the past. In this chapter, a recent advance in technology-aware integrated inductor design is presented, where drawbacks of the integrated inductor design are addressed by introducing an equation-based inductor synthesis algorithm. The intelligent computation technique aims to allow RF designers to optimize integrated inductors, given the inductor center frequency dictated by the device application, and geometry constraints. This does not only lay down a foundation for system-level RF circuit performance optimization, but, because inductors are often the largest parts of an RF system, it also allows for optimal usage of chip real estate

    Bioimaging of liver cancer cells incubated with partially reduced graphene oxide

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    Functional materials based on graphene oxide (GO) and reduced graphene oxide (rGO) have a high potential for application in the fields of biophysics, material science, and biomedical engineering [1]. It is due to their tunable physical properties, high surface area, remarkable photoluminescence, as well as their controllable chemical functionalization [2]. Beyond their applications in nanomedicine for drug/gene delivery, phototherapy and bioimaging, they have shown significant interaction and adhesive properties with proteins, mammalian cells and microorganisms, which makes them potential candidates for multifunctional biological applications. In this lecture, we will present a study of the interaction of partially reduced graphene oxide (prGO) with Huh7.5.1 liver cancer cells. The study was conducted by means of synchrotron excitation DUV fluorescence bioimaging (performed on DISCO beamline of synchrotron SOLEIL) [3]. The prGO sample was obtained by the reduction (to a certain extent) of the initially prepared GO nanosheets. The fluorescence of the GO nanosheets increases with time of the reduction due to a change in the ratio of the sp2 and sp3 carbon sites, and the prGO sample was extracted from the dispersion when the intensity of the fluorescence reached its maximum. After that, Huh7.5.1 cells were incubated with GO, prGO and rGO nanosheets and used in bioimaging studies. The presence of graphene materials influenced the fluorescence properties of the cells, and by analyzing fluorescence photobleaching dynamics, we were able to localize graphene nanosheets inside the liver cancer cells.VII International School and Conference on Photonics : PHOTONICA2019 : Abstracts of Tutorial, Keynote, Invited Lectures, Progress Reports and Contributed Papers; August 26-30; Belgrad

    Structural Investigations of Polyvinyliden Fluoride Thin and Thick Films

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    Polyvinyliden fluoride (PVDF) is a low-density fluoropolymer that exhibits piezoelectric and pyroelectric properties. It can be used in the chemical, semiconductor, medical and defense industries, as well as in aviation and aerospace applications. Crucial factors that lead to the PVDF ferroelectric properties and determine its piezoelectric, mechanical, optical, electrical and thermal properties are its polar conformations, crystal structure, and crystallinity. These characteristics of the material significantly depend on the conditions used in the processing of polymer films. Therefore, we investigated structure and morphology of thin and thick PVDF films obtained by spin coating and solution casting methods, respectively. Structural investigations of PVDF thin and thick films were performed by the X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Fourier transform infrared spectrometry (FTIR) methods, while microstructure morphology has been analyzed by scanning electron microscope (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Present results will enable optimization of PVDF processing techniques for the production of pressure and IR sensors

    Electronic structure of silver-bismuth iodide rudorffite nanomaterials studied by synchrotron radiation soft X-ray photoemission spectroscopy

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    Silver-bismuth iodide (Ag-Bi-I) rudorffites are chemically stable and non-toxic materials that can act as a possible replacement for methylammonium lead halide perovskites in optoelectronic devices. In this report we will present innovative routes for fabrication of AgBi-I nanomaterials, as well as the results of the investigation of the electronic structure of isolated Ag-Bi-I nanoparticles by soft X-ray aerosol photoemission spectroscopy [1, 2]. Aerosol photoemission spectroscopy allows studies of the electronic structure of submicrometer particles that are free from the influence of a substrate or solvent [1-5]. In this approach the aerosol particles can be produced directly from a solution or a colloidal dispersion, which opens a possibility for investigation of a variety of nanosystems that can be produced by wet chemistry methods. This technique relies on the interaction of focused beam of isolated particles with ionizing radiation under high vacuum conditions. In addition, by using tunable synchrotron radiation as an excitation source it is possible to obtain highresolution photoelectron spectra in the investigated photoelectron energy range.X Serbian Ceramic Society Conference - Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts; September 26-27, 2022; Belgrad

    A fluorescent nanoprobe for single bacterium tracking: functionalization of silver nanoparticles with tryptophan to probe the nanoparticle accumulation with single cell resolution

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    The investigation of the interaction of silver nanoparticles and live bacteria cells is of particular importance for understanding and controlling their bactericidal properties. In this study, the process of internalization of silver nanoparticles in Escherichia coli cells was followed by means of synchrotron excitation deep ultraviolet (DUV) fluorescence imaging. Antimicrobial nanostructures that can absorb and emit light in the UV region were prepared by functionalization of silver nanoparticles with tryptophan amino acid and used as environmentally sensitive fluorescent probes. The nanostructures were characterized by morphological (TEM) and spectroscopic methods (UV-vis, FTIR, XPS, and photoluminescence). The TEM images and the analyses of the UV-vis spectra suggested that the addition of tryptophan led to the formation of hybrid nanostructures with pronounced eccentricity and larger sizes with respect to that of the initial silver nanoparticles. The DUV imaging showed that it was possible to distinguish the fluorescent signal pertaining to silver-tryptophan nanostructures from the autofluorescence of the bacteria. The spatial resolution of the fluorescence images was 154 nm which was sufficient to perform analyses of the accumulation of the nanostructures within a single bacterium. The DUV imaging results imply that the tryptophan-functionalized silver nanoparticles interact with cell membranes via insertion of the amino acid into the phospholipid bilayer and enter the cells

    Roadmap on dynamics of molecules and clusters in the gas phase

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    This roadmap article highlights recent advances, challenges and future prospects in studies of the dynamics of molecules and clusters in the gas phase. It comprises nineteen contributions by scientists with leading expertise in complementary experimental and theoretical techniques to probe the dynamics on timescales spanning twenty order of magnitudes, from attoseconds to minutes and beyond, and for systems ranging in complexity from the smallest (diatomic) molecules to clusters and nanoparticles. Combining some of these techniques opens up new avenues to unravel hitherto unexplored reaction pathways and mechanisms, and to establish their significance in, e.g. radiotherapy and radiation damage on the nanoscale, astrophysics, astrochemistry and atmospheric science
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