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Porosity Determination of Carbon and Glass Fibre Reinforced Polymers Using Phase-Contrast Imaging
摘要： This paper presents multi-modal image data of different fibre reinforced polymer samples acquired with a desktop Talbot-Lau grating interferometer (TLGI) X-ray computed tomography (XCT) system and compare the results with images acquired using conventional absorption-based XCT. Two different fibre reinforced polymer samples are investigated: (i) a carbon fibre reinforced polymer (CFRP) featuring a copper mesh embedded near the surface for lightning conduction and (ii) a short glass fibre reinforced polymer (GFRP) sample. The primary goal is the non-destructive detection of internal defects such as pores and the quantification of porosity. TLGI provides three imaging modalities including attenuation contrast (AC) due to absorption, differential phase contrast (DPC) due to refraction and dark-field contrast (DFC) due to scattering. In the case of the CFRP sample, DPC is less prone to metal streak artefacts improving the detection of pores that are located close to metal components. In addition, results of a metal artefact reduction (MAR) method, based on sinogram inpainting and an image fusion concept for AC, DPC and DPC, are presented. In the case of the GFRP sample, DPC between glass fibres and matrix is lower compared to AC while DPC shows an increased contrast between pores and its matrix. Porosity for the CFRP sample is determined by applying an appropriate global thresholding technique while an additional background removal is necessary for the GFRP sample.
关键词： Porosity,Carbon and glass fibre reinforced polymers,Talbot-Lau grating interferometer,X-ray computed tomography,Differential phase contrast
更新于2025-09-23 15:22:29
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Methods for obtaining characteristic γ-ray net peak count from interlaced overlap peak in HPGe γ-ray spectrometer system
摘要： For a characteristic c-ray with interlaced overlap peak, and the case where its reliable and credible net count cannot be obtained using the current high-purity germanium (HPGe) multichannel c-ray spectrum software, two new methods are proposed herein to obtain the c-ray net peak count from the interlaced overlap peak in the HPGe c-ray spectrometer system, of which one is the symmetric conversion method based on Gaussian distribution and the other is where the energy average value of two close c-rays is regarded as the c-ray energy. The experimental results indicate that the two methods mentioned above are reliable and credible. This study is signi?cant for the development of better c-ray spectrum processing software for measuring complex c-ray spectra concerning the nuclear reaction cross section, neutron activation analysis, and analysis of transuranium elements, using an HPGe detector.
关键词： High-purity germanium (HPGe) c-ray spectrometer system,Peak count,Interlaced overlap peak
更新于2025-09-23 15:22:29
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Enhanced degradation of BPA in water by PANI supported Ag/TiO2 nanocomposite under UV and visible light
摘要： PANI supported Ag@TiO2 nanocomposite was synthesized via oxidative polymerization of aniline on Ag@TiO2. The Ag@TiO2 nanocomposite was synthesized by the photo reduction of Ag nanoparticles on hydrothermally synthesized TiO2 nanofibers. Raman analysis revealed that the anatase phase of TiO2 was synthesized showing typical peaks at 195 cm-1, 396 cm-1, 514 cm-1, and 637 cm-1. The incorporation of PANI, a carbonaceous material was confirmed by appearance of D-band and G-band in Ag@TiO2-PANI that were located at 1505 cm-1 and 1603 cm-1 respectively. X-ray diffraction (XRD) analysis confirmed the anatase phase of TiO2 was synthesized. Transmission electron microscopy analysis (TEM) analysis revealed that TiO2 nanofibers were synthesized successfully and Ag nanoparticles of different sizes were deposited on their surface. X-ray Photon Spectroscopy (XPS) survey scan of the Ag@TiO2-PANI-nanocomposite revealed that the nanocomposite was made from C, O, Ag, Ti, and N. DRS and Tauc`s plot estimated the band gap of Ag@TiO2-PANI to be 3.0 eV. A comparative study of the photocatalytic performance of Ag@TiO2-PANI catalyst showed better degradation performance under both conditions than pristine TiO2, and Ag@TiO2 with a degradation of up to 99.7% under visible light irradiation. The degradation experiments showed that the reactive species that were dominant in the degradation of BPA were h+ and .O2-. The nanocomposite was re-used to degrade BPA for up to four cycles without losing much of its photocatalytic ability with a removal of at least 90% in the fourth cycle.
关键词： Bisphenol A,Ag@TiO2-PANI,visible light,X-ray photoelectron spectroscopy,UV
更新于2025-09-23 15:22:29
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A Study of ΔΣ-CDS Algorithm for X-ray CCD Applications
摘要： Correlated double sampling (CDS) circuits are essential to processing the X-ray charge-coupled devices (CCDs) that have been used in the modern X-ray astronomical field. For spectroscopy observations, the energy resolution is of decisive importance. In this paper, a comprehensive study of the CDS algorithm based on the incremental ΔΣ technique, named ΔΣ-CDS algorithm hereafter, is studied. Theoretical and practical aspects for modulations and demodulations for applications with different pixel rates (PRs) are discussed. The concepts of differential cascade-of-integrator (DCoI) filter and truncated cascaded-integrator-comb (TCIC) filter are extensively investigated from both time-domain and frequency-domain analyses. The operating principles, prototype design and experimental results are addressed. As a prototype for 100 kHz PR, a readout integrated circuit (ROIC) is designed. When tested with the target X-ray CCD–CCD236 using a 1 μCi 55Fe radioisotope, the ROIC achieves an energy resolution characterized by the full-width-at-half-maximum (FWHM) as 132.4±2.4 eV at 5.9 keV which is very close to the 121 eV limit of CCD236.
关键词： X-ray CCD,TCIC,ΔΣ-CDS,ROIC,DCoI
更新于2025-09-23 15:22:29
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Effect of thickness and post deposition annealing temperature on the structural and optical properties of thermally evaporated molybdenum oxide films
摘要： In this paper, the influence of thickness and post deposition annealing temperature on thermally evaporated molybdenum oxide films has been studied. The X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) are used for crystal structural and surface morphological characterization of the films, respectively. The XRD analysis showed that the presence of α-MoO3 and MoO2 crystalline phase of the films annealed at elevated temperature ~ 250 °C after deposition. The optical constants are determined from UV–Vis transmission spectra. The optical band gap and Urbach energy is found to be temperature dependent. The refractive index of the films is estimated by the optical method as well as cross-sectional SEM image analysis. It is found that the refractive index of the films increases from ~ 1.70 to 2.03 with the decrease in film thickness from ~ 2.9 to 1.7 μm. It is also observed that the refractive index decreased from ~ 2.03 to 1.61 with the increase in post deposition annealing temperature from room temperature (RT) to ~ 250 °C. Moreover, extinction coefficient, optical conductivity, porosity, and film density are investigated as a function of source-substrate distance and post deposition annealing temperature. The Photoluminescence (PL) properties of the films are also investigated by recording spectra under the excitation wavelength at 250 nm.
关键词： Optical constants,Molybdenum oxide,X-ray diffraction,Thermal evaporation,Scanning electron microscope
更新于2025-09-23 15:22:29
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One-dimensional coordination polymers based on a new 3-position substituted imidazo[1,2-a]pyridine ligand: Crystal structures, photoluminescent and magnetic properties
摘要： A new 3-position substituted imidazo[1,2-a]pyridine ligand, namely, 5-(2-chloroimidazo[1,2-a]pyridine-3-carboxamido) isophthalic acid (H2L) was synthesized and characterized by 1H NMR spectroscopy. Based on this ligand, three isostructural one-dimensional coordination polymers, [ML(H2O)2]n (M = Zn (1), Ni (2) and Co (3)) were synthesized under the solvothermal conditions, and structurally characterized by single crystal X-ray diffraction, infrared spectroscopy, powder X-ray diffraction and elemental analyses. The coordination polymer 1 reveals similar photoluminescent spectrum to H2L ligand, but possesses the enhanced phosphorescent emission and higher phosphorescent quantum yield, compared to H2L ligand. Furthermore, the magnetic properties of coordination polymers 2 and 3 have been investigated, the results show there are antiferromagnetic interactions between the NiII ions or CoII ions in 2 or 3.
关键词： Photoluminescence,Coordination polymers,Imidazo[1,2-a]pyridine,X-ray structures,Magnetic properties
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE 4th International Forum on Research and Technology for Society and Industry (RTSI) - Palermo, Italy (2018.9.10-2018.9.13)] 2018 IEEE 4th International Forum on Research and Technology for Society and Industry (RTSI) - Structural and Optical Behaviour of MAPbI<inf>3</inf> Layers in Nitrogen and Humid Air
摘要： The tendency of MA+-containing perovskites to degradation under humid air is still the main challenge which limits the durability of technologies. We indeed frame the behavior of MAPbI3 layer through structural and optical characterization under thermal cycles and using the environmental composition as a variable parameter (humid air, N2, Ar, O2). Within the temperature range explored (RT-80°C) we likely approach the thermal operation of the material under the sun and find that the degradation mechanism is linked to the action of water molecules by the formation of lattice defects. They rise the lattice disorder, especially at the crossover of the tetragonal to cubic transition wherein an acceleration of the degradation kinetics is observed. Nitrogen can help rationalizing solutions to stabilize the materials even at this critical transition step, since it behaves as more than an inert species.
关键词： Spectroscopic Ellipsometry,Photovoltaics,X-ray diffraction,Hybrid Perovskites,Stability,Thermal Cycle
更新于2025-09-23 15:22:29
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ZnO-based nanocomposites prepared by a vapor phase route, investigated by XPS
摘要： Nanostructured materials based on ZnO, eventually functionalized with titanium oxide (TiO2) or tungsten oxide (WO3), were fabricated on fluorine-doped tin oxide-coated glass substrates by a combined chemical vapor deposition/radio frequency-sputtering route. In particular, the present work focuses on the use of x-ray photoelectron and x-ray excited Auger electron spectroscopies for a detailed investigation of the system O 1s, Zn 2p3/2, Zn 3p, and Zn LMM core levels, as well as Ti 2p and W 4f photoelectron peaks. In a nutshell, the results of these analyses highlight the obtainment of pure ZnO nanodeposits, as well as of ZnO-TiO2 and ZnO-WO3 composites, in which the identity of each component is preserved, and the occurrence of an electronic interplay between ZnO and WO3 phases in the latter system.
关键词： RF-sputtering,CVD,x-ray photoelectron spectroscopy,WO3,TiO2,ZnO
更新于2025-09-23 15:22:29
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Conformal image-guided microbeam radiation therapy at the ESRF biomedical beamline ID17
摘要： Purpose: Upcoming veterinary trials in microbeam radiation therapy (MRT) demand for more advanced irradiation techniques than in preclinical research with small animals. The treatment of deep-seated tumors in cats and dogs with MRT requires sophisticated irradiation geometries from multiple ports, which impose further efforts to spare the normal tissue surrounding the target. Methods: This work presents the development and benchmarking of a precise patient alignment protocol for MRT at the biomedical beamline ID17 of the European Synchrotron Radiation Facility (ESRF). The positioning of the patient prior to irradiation is verified by taking x-ray projection images from different angles. Results: Using four external fiducial markers of 1.7 mm diameter and computed tomography-based treatment planning, a target alignment error of less than 2 mm can be achieved with an angular deviation of less than 2?. Minor improvements on the protocol and the use of smaller markers indicate that even a precision better than 1 mm is technically feasible. Detailed investigations concerning the imaging dose lead to the conclusion that doses for skull radiographs lie in the same range as dose reference levels for human head radiographs. A currently used online dose monitor for MRT has been proven to give reliable results for the imaging beam. Conclusions: The ESRF biomedical beamline ID17 is technically ready to apply conformal image-guided MRT from multiple ports to large animals during future veterinary trials.
关键词： microbeam radiation therapy,image-guidance,x-ray imaging,fiducial markers,synchrotron radiation
更新于2025-09-23 15:22:29
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Resolving the nature of electronic excitations in resonant inelastic x-ray scattering
摘要： The study of elementary bosonic excitations is essential toward a complete description of quantum electronic solids. In this context, resonant inelastic x-ray scattering (RIXS) has recently risen to becoming a versatile probe of electronic excitations in strongly correlated electron systems. The nature of the radiation-matter interaction endows RIXS with the ability to resolve the charge, spin, and orbital nature of individual excitations. However, this capability has been only marginally explored to date. Here, we demonstrate a systematic method for the extraction of the character of excitations as imprinted in the azimuthal dependence of the RIXS signal. Using this approach, we resolve the charge, spin, and orbital nature of elastic scattering, (para-)magnon/bimagnon modes, and higher-energy dd excitations in magnetically ordered and superconducting copper oxide perovskites (Nd2CuO4 and YBa2Cu3O6.75). Our method derives from a direct application of scattering theory, enabling us to deconstruct the complex scattering tensor as a function of energy loss. In particular, we use the characteristic tensorial nature of each excitation to precisely and reliably disentangle the charge and spin contributions to the low-energy RIXS spectrum. This procedure enables to separately track the evolution of spin and charge spectral distributions in cuprates with doping. Our results demonstrate a new capability that can be integrated into the RIXS toolset and that promises to be widely applicable to materials with intertwined spin, orbital, and charge excitations.
关键词： spin,resonant inelastic x-ray scattering,cuprates,azimuthal dependence,RIXS,electronic excitations,orbital,charge
更新于2025-09-23 15:22:29