Dynamical Diffraction Research Articles

Hole drilling in basalt-reinforced sustainable composites using abrasive waterjet for construction applications

This study aimed to develop, characterize, and optimize abrasive waterjet (AWJ) machining of sustainable basalt fiber-reinforced polymer composites for construction and industrial applications. Dynamic mechanical analysis, thermogravimetric analysis, and X-ray diffraction revealed enhanced thermal stability, increased decomposition temperatures, and improved crystallinity, correlating with improved tensile strength of developed composites. To address drilling-induced damage that can compromise long-term quality and applicability, AWJ drilling parameters were optimized to minimize damage while enhancing material removal rates. A novel quantification method for entry total surface damage (ETD) was implemented to assess machining defects. Results showed that standoff distance significantly influences ETD and exit delamination, while higher water pressure reduces entry damage. Abrasive flow rate primarily affected the material removal rate. FE-SEM analysis revealed microstructural changes in drilled surfaces, including damage zones and matrix fractures specific to AWJ processing. Multi-objective optimization using Genetic Algorithm is performed to enable flexible parameter selection and informed decision making, balancing machining efficiency and minimal damage.

Dynamic X-ray Coherent Diffraction Analysis: Bridging the Time Scales between Imaging and Photon Correlation Spectroscopy.

The advent of diffraction limited sources and developments in detector technology opens up new possibilities for the study of materials in situ and operando. Coherent X-ray diffraction techniques such as coherent X-ray diffractive imaging (CXDI) and X-ray photon correlation spectroscopy (XPCS) are capable for this purpose and provide complementary information, although due to signal-to-noise requirements, their simultaneous demonstration has been limited. Here, we demonstrate a strategy for the simultaneous use of CXDI and XPCS to study in situ the Brownian motion of colloidal gold nanoparticles of 200 nm diameter suspended in a glycerol-water mixture. We visualize the process of agglomeration, examine the spatiotemporal space accessible with the combination of techniques, and demonstrate CXDI with 22 ms temporal resolution.

Preparation of New Liposomal Daunorubicin and Evaluation of its Anti-colorectal Cancer in HCT116 Cells

Background: Colorectal cancer (CRC) is the third most common cause of cancerrelated deaths worldwide. To develop more effective anti-CRC drugs, this research evaluated the impact of synthesized liposomal daunorubicin on HTC116 colon cancer cell line. Methods: Liposomal daunorubicin (LDNR) was synthesized by the thin layer hydration method and size was determined by dynamic light diffraction (DLS). MTT assay was used to determine the cytotoxicity and IC50 of LDNR against the HCT116 CRC cell line. Relative mRNA expression of the NF-κB gene and apoptosis were evaluated in 24 hours treatments of HCT116 cells by qRT-PCR and flow cytometry, respectively. Results: The hydrodynamic diameter of liposomes containing daunorubicin (DNR) was determined 25.2 nm. MTT assay showed a 38% decrease in HCT116 cells viability after 24-hour treatment with the DNR (0.5 μM). The lowest (0.125 μM) and highest (2 μM) dose of LDNR showed 20.4% and 71.6% cytotoxicity, respectively. LDNR showed dose-dependent cytotoxicity with the IC50 of 0.87 μM. The phase contrast microscope evaluation confirmed the LDNR cytotoxicity. The DNR and LDNR (0.87 μM) decreased relative mRNA levels of NF-κB 63% (P= 0.023) and 99.6% (P=0.003), respectively. The percentage of apoptotic cells in the DNR and LDNR increased by 27.1% (P<0.0001) and 49.7% (P<0.0001), respectively. Conclusion: DNR increases the rate of apoptosis by decreasing the NF-κB gene expression in HCT116 cells. These effects are intensified in the liposomal form. Therefore, the LDNR produced in this research can be considered in the treatment of CRC.

Dynamic Wavelength-Selective Diffraction and Absorption with Direct-Patterned Hydrogel Metagrating.

Hydrogel nanophotonic devices exhibit attractive tunable capabilities in structural coloration and optical display. However, current hydrogel-based tunable strategies are mostly based on a single physical mechanism, and it remains a challenge to merge multiple mechanisms for active devices with integrated functionalities. Here, a hydrogel metagrating combining Fabry-Pérot (FP) resonance and diffraction effects is proposed for achieving tunable absorption and dynamic wavelength-selective beam steering. Through exploiting hydrogel shrinkage under electron-beam exposure, a hydrogel nanocavity composed of Ag/Hydrogel/Ag three-layer films can be directly printed with arbitrary patterns, enabling the direct-pattering technique of metagrating. The hydrogel nanocavity performs as an FP-type absorber, and its absorption peak rapidly shifts with humidity variation due to the hydrogel layer scaling. The response speed is <320ms, and the absorption peak shift range is >150nm. It is further demonstrated that the hydrogel metagrating exclusively deflects light at the resonance wavelength, and its operating wavelength can be actively switched by regulating ambient humidity. The proposed tunable hydrogel metagrating can promote new technologies of tunable metasurfaces for optical filtering, gas sensing, and optical imaging.

An alternative method to the Takagi-Taupin equations for studying dark-field X-ray microscopy of deformed crystals.

This study introduces an alternative method to the Takagi-Taupin equations for investigating the dark-field X-ray microscopy (DFXM) of deformed crystals. In scenarios where dynamical diffraction cannot be disregarded, it is essential to assess the potential inaccuracies of data interpretation based on the kinematic diffraction theory. Unlike the Takagi-Taupin equations, this new method utilizes an exact dispersion relation, and a previously developed finite difference scheme with minor modifications is used for the numerical implementation. The numerical implementation has been validated by calculating the diffraction of a diamond crystal with three components, wherein dynamical diffraction is applicable to the first component and kinematic diffraction pertains to the remaining two. The numerical convergence is tested using diffraction intensities. In addition, the DFXM image of a diamond crystal containing a stacking fault is calculated using the new method and compared with the experimental result. The new method is also applied to calculate the DFXM image of a twisted diamond crystal, which clearly shows a result different from those obtained using the Takagi-Taupin equations.

Preliminary Study of Stone Sawing Sludges-based Alkali Activated Materials (AAMs) for the Conservation of Archaeological Ceramics

This paper presents research into the feasibility of using stone sawing sludge-based Alkali Activated Materials (AAMs) for conservation of Cultural Heritage. Sawing sludges are a stone processing waste product resulting from the mixing of rock powder with the water used to cool down the cutting blades. The chemical composition of the sawing sludges, when aluminosilicatic, is suitable for acting as a precursor to produce AAMs. AAMs are known for their low environmental impact and versatility since their existence is drawn from recycling waste materials. One of their possible applications is in the conservation of Cultural Heritage objects. This work presents a preliminary investigation into three sawing sludge-based AAMs with different mineralogical compositions and contributes to formulating guidelines for applying them as fillers on modern and archaeological ceramic pottery based on the evaluation of their workability, appearance and physical properties over time from the moment of application and up to 30 days. Dynamic Vapor Sorption and X-Ray Diffraction results provided an overview of the structural and mineralogical changes under high RH conditions, where the tested AAMs showed a type II isotherm curve, as expected for concrete-like materials, as well as disappearance of thermonatrite after one isothermal cycle. Ultrasonic Pulse Velocity test demonstrated the general homogeneity of the AAMs despite the lower velocity exhibited by one of the formulations, probably due to its internal pore distribution and possible presence of microstratification. The Oddy tests, application tests and colourimetric measurements evidenced the advantages and weaknesses of the AAMs, with overall encouraging results ensuing investment in further in-depth studies of these innovative conservation materials in view of their future use in the field of conservation of Cultural Heritage as a result of a circular economy model.

Prospect for detecting magnetism in two-dimensional perovskite oxides by electron magnetic circular dichroism

Two-dimensional (2D) magnets, especially strongly correlated 2D transition-metal perovskite oxides, have attracted significant attention due to their intriguing electromagnetic properties for potential applications in spintronic devices. Potentially electron magnetic circular dichroism (EMCD) under zone axis conditions can provide three-dimensional components of magnetic moments in 2D materials, but the collection efficiency and the signal-to-noise ratio for out-of-plane (OOP) components is limited due to the limited collection angle. Here we conducted a comprehensive computational simulation to optimize the experimental setting of EMCD for detecting the OOP components of magnetic moments in three beam conditions (3BCs) on 2D perovskite oxides La1-xSrxMnO3 (LSMO) in a TEM. The key parameters are sample thickness, accelerating voltage, Sr doping concentration, collection semi-angle and position, and sample orientation including systematic reflections excited and tilt angle. Our simulation results demonstrate that the relative dynamical diffraction coefficients of Mn OOP EMCD of LaMnO3 with a thickness ranging from 1 unit cell (uc) to 4 uc can be optimized in a 3BC with (110) systematic reflections excited and a relatively large collection semi-angle of 19 mrad at the relatively low accelerating voltage of 80 kV. In most cases, the relative dynamic diffraction coefficients for La1-xSrxMnO3 with the thickness ranging from 1 uc to 4 uc decrease with the increase of the Sr doping concentrations. The optimal tilt angle from a zone axis to a 3BC is 18° for the cases of the LSMO thickness of 2 uc, 3 uc and 4 uc, and 22° for the monolayer LSMO. Our work provides the theoretical simulation foundation for optimized EMCD experiments for measuring OOP components of magnetic moments in 2D transition-metal perovskite oxides.

Hydro-abrasive erosion in Kaplan turbines: a case study

ABSTRACT Sediment in the flowing water causes hydro-abrasive erosion of hydraulic turbines and other underwater components. In the present study, erosion quantification in the Kaplan turbine of a low-head hydropower plant (HPP) on the Upper Ganga Canal, is considered in the study. The study uses the guidelines of the International Electrotechnical Commission IEC 62364: 2019 for quantifying erosion in the Kaplan turbine. This work extends the research of Rai and Kumar (2016) and uses their primary details of some suspended sediment and operating parameters. The shape and mineral composition of the suspended sediment were quantified using dynamic imaging and X-ray diffraction techniques, respectively. The annual average particle load at the study HPP is obtained to be 356.87 kg·h/m3. Based on the analysis, it is estimated that the erosion depth varies from 0.88 to 1.37 mm/year at the blade tip, whereas from 2.40 to 3.74 mm/year at the blade outlet. At the runner chamber, the erosion depth varies from 1.27 to 1.98 mm/year. The erosion depth varies from 0.01 to 1.53 mm/year in the guide vanes. The calibration factor corresponding to the maximum erosion in guide vanes is estimated to be 1.75 × 10−5.

Effects of dynamic diffraction in coherent X-ray radiation from a beam of relativistic electrons in a periodic layered medium with three layers in a period

The possibilities of manifestation of dynamic diffraction effects in coherent X-ray radiation (CXR) of relativistic electrons in a periodic layered medium (PLM) with three different layers in a period are being investigated. A dynamic theory of CXR of relativistic electrons has been developed for the case of such a target. The corresponding formulas for the spectral-angular characteristics of parametric X-ray radiation (PXR) and diffracted transition radiation (DTR) are obtained and studied. The influence of asymmetric diffraction on the spectral-angular densities of PXR and DTR is shown. A striking effect of anomalous photoabsorption in PXR in a layered target, similar to the Bormann effect in a single crystal, is predicted.

Computerized simulation of 2-dimensional phase contrast images using spiral phase plates in neutron interferometry

Abstract We present calculations of interferograms (interference patterns) of one or multiple spiral phase plates that would be observed with a perfect crystal neutron interferometer of Mach–Zehnder type. A spiral phase plate (SPP) in one of the two coherent beam paths produces a twist in the phase front and thus a vortex beam with intrinsic angular momentum, which in the case of neutrons should be observed as a characteristic interference pattern that appears complementary to each other in both detectors behind the interferometer. Adding additional SPPs in one beam path of the interferometer yield interference patterns similar to that of a single SPP but only due to the cumulative step height. All simulated interferograms have been calculated on the basis of dynamical neutron diffraction without any assumption of a neutron orbital angular momentum and show very convincing agreement with experimental results from the literature, see e.g. (C. W. Clark, R. Barankov, M. G. Huber, M. Arif, D. G. Cory, and D. A. Pushin, “Controlling neutron orbital angular momentum,” Nature, vol. 525, pp. 504–506, 2015). In particular, this clarifies, that the cited experiments do not give evidence of the quantization of interactions caused by a twist of the phase front of a neutron wave in the interferometer and thus no evidence for the effect of a neutron orbital angular momentum.

Асимметричная рентгеновская дифракция ограниченных пучков в кристаллах

Asymmetric dynamic diffraction of confined X-ray beams in crystals has been theoretically studied using Takagi–Taupin equations, including numerical solution using nodal grid and calculations of X-ray fields in Fourier space. We have fulfilled simulation of scattering intensity distribution maps from silicon crystal near reciprocal lattice site depending on size of X-ray beams.

Dynamic surface gratings for optical encryption: A simple approach based on azobenzene photoisomerization and solvent engineering

Dynamic diffraction gratings are optical devices that allow for non-mechanical, non-contact and remote on-demand control, and have garnered significant interest in optical encryption. Azobenzene materials are ideal materials for developing dynamic gratings owing to the advantages of fast photo isomerization and good reversibility. It is still challenging to precisely fabricate ordered periodic gratings on the surfaces of azobenzene materials. Here, controllable dynamic grating patterns were successfully fabricated by mask exposure and solvent engineering on azobenzene polyamide acid (PAA-Azo)-solvent system. The movement and mass migration of polymer chains can be regulated by modulating the intermolecular hydrogen bonding and free volume based on different solvents and solvent contents within the system, resulting in the formation of surface gratings with customizable morphology and light-splitting ability. Finally, by regulating the periodicity and amplitude of gratings, colorful dynamic patterns were obtained to monitor the expiration of light-sensitive and short shelf-life products, based on the azobenzene polyamide acid (PAA-Azo)-solvent system. This work provides a new and simple approach for controllable preparation of high-regularity and high-performance dynamic gratings.

Effect of crosslinker molecular weight on the characteristics of thermoelectric ionogels

Abstract The present study investigates an ionic thermoelectric gel with adjustable functionality through the manipulation of crosslinker molecular weight. The thermoelectric properties of 2-hydroxyethyl acrylate (2-HEA) ionogels, prepared using PEGDA200, PEGDA575, and PEGDA1000 as crosslinkers, were thoroughly examined. Furthermore, dynamic thermal mechanical analysis (DMA) and X-ray diffraction (XRD) techniques were employed to elucidate the underlying reasons for variations in the thermoelectric material properties resulting from changes in crosslinker molecular weight. Notably, the thermoelectric gel synthesized with PEGDA575 exhibited a remarkable thermal power output of 19.19 mV•K-1 along with a tensile capacity of 231%. Additionally, the developed ionic thermoelectric capacitor demonstrated an impressive energy density of 4.288 J•m−2, thereby showcasing its potential application in flexible low-grade heat energy recovery devices.

Comparative characterization and dyeing properties of poly(ethylene terephthalate-co-polyethylene glycol) fibers and poly(ethylene terephthalate) fibers

A comparative characterization of poly(ethylene terephthalate-co-polyethylene glycol) (PCP) fibers was performed using various parameters, including chemical and supramolecular structures, thermal properties, and physical properties. Dynamic scanning calorimetry and X-ray diffraction analyses revealed that PCP exhibits a lower melting point, glass transition temperature, and crystallinity than PET. In terms of tensile properties, PCP exhibited reduced tensile strength but increased elongation at break, indicating enhanced toughness. Dyeing test results demonstrated that PCP fibers are disperse dyeable at lower temperatures and exhibited optimal dyeability at 100 °C, surpassing PET, without compromising leveling properties or color fastness. These findings underscore the potential for energy savings and process streamlining through atmospheric-pressure dyeing.

Production of nanocomposite films based on low density polyethylene/surface activated nanoperlite for modified atmosphere packaging applications

The modified atmosphere packaging films based on polyethylene nanocomposites reinforced with perlite nanoparticles were prepared using a blow molding machine. The perlite particles were first reduced to nano dimensions using an abrasive mill, then the porosity of nanoperlite was increased to improve their efficiency in absorbing ethylene gas. For this purpose, 6 normal sodium hydroxide solution at 50°C temperature was used. Finally, perlite nanoparticles were modified by polymethyl hydrogen siloxane silane compound. In each of the stages of grinding and modifying the perlite surface, the necessary tests including dynamic light diffraction test, nitrogen absorption test and ethylene gas absorption test were performed using gas chromatography method. The results showed that the size of perlite particles was reduced to 500 nm by using an abrasive mill, and the surface modification process increased the specific surface area of perlite by 10 times. Based on this, the amount of ethylene gas absorption in perlite nanoparticles with modified surface increased up to 3 times compared to normal perlite. The results of the gas chromatography test showed that the nanocomposite film based on polyethylene reinforced with 6% by weight of modified perlite nanoparticles has several times the efficiency in absorbing ethylene gas compared to the potassium permanganate sachets The results of the mechanical properties tests of nanocomposite film in comparison with pure polyethylene film showed that nanocomposite film has higher properties than pure polyethylene. The results of shelf-life tests of green tomatoes packed in nanocomposite film based on polyethylene reinforced with modified nanoperlite showed that green tomatoes can be stored for two months using the prepared modified atmosphere packaging.

Characterization Methods to Determine Interpenetrating Polymer Network (IPN) in Hydrogels.

Significant developments have been achieved with the invention of hydrogels. They are effective in many fields such as wastewater treatment, food, agriculture, pharmaceutical applications, and drug delivery. Although hydrogels have been used successfully in these areas, there is a need to make them better for future applications. Interpenetrating polymer networks (IPNs) can be created to make hydrogels more adjustable and suitable for a specific purpose. IPN formation is an innovative approach for polymeric systems. It brings two or more polymer networks together with entanglements. The properties of IPNs are controlled by its chemistry, crosslinking density, and morphology. Therefore, it is necessary to understand characterization methods in order to detect the formation of IPN structure and to develop the properties of hydrogels. In recent studies, IPN structure in hydrogels has been determined via chemical, physical, and mechanical methods such as Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), X-ray diffraction (XRD), and rheology methods. In this paper, these characterization methods will be explained, recent studies will be scrutinized, and the effectiveness of these methods to confirm IPN formation will be evaluated.

An Electrochemically Programmable Metasurface with Independently Controlled Metasurface Pixels at Optical Frequencies.

Metasurfaces have revolutionized optical technologies by offering powerful, compact, and versatile solutions to control light. Conducting polymers, characterized by their conjugated molecular structures, facilitate charge transport and exhibit interesting electrical, optical, and mechanical properties. Integrating conducting polymers with optical metasurfaces can unlock new opportunities and functionalities in modern optics. In this work, we demonstrate an electrochemically programmable metasurface with independently controlled metasurface pixels at optical frequencies. Electrochemical modulation of locally conjugated polyaniline on gold nanorods, which are arranged on addressable electrodes according to the Pancharatnam-Berry phase design, enables dynamic control over the metasurface pixels into programmable configurations. With the same metasurface device, we showcase diverse optical functions, including dynamic beam diffraction and varifocal lensing along and off the optical axis. The synergy between flat optics and conducting polymer science holds immense potential to enhance the performance and function versatility of metasurfaces, paving the way for innovative optical applications.

DENNIS: a design and analysis tool for dynamic material x-ray diffraction experiments

We present DENNIS (Diffraction Experiment desigN and aNalysiS): a graphical software tool useful for the design and analysis of dynamic x-ray diffraction experiments, such as those performed on the Z Pulsed Power Facility, Thor Pulsed Power Generator, and Dynamic Compression Sector (DCS) of the Advanced Photon Source. DENNIS provides rapid powder and single-crystal diffraction pattern predictions and powder diffraction pattern image integration in three-dimensional geometries. Additional features include crystallographic information file reading, image processing, and synthetic diffraction pattern image generation. We overview the software's capabilities, detail the prediction and integration methodologies, and provide example implementations on Z and DCS experiments.

Compact hard x-ray flash radiography device based on wire-shorted low-impedance rod pinch diode.

A rod pinch diode (RPD) is a feasible load configuration to generate a high-brightness, small-size hard x-ray radiation source. In this paper, the radiography performance of a wire-shorted low-impedance RPD on a compactly designed table-top driver (WRPD-1) is demonstrated for the first time. The driver consists of four high-power discharge branches connected in parallel, with each branch consisting of two metal-film capacitors and one multigap field-distortion switch in series. The four branches are triggered synchronously to generate a fast-rising current pulse: the inductance of the load section at the short circuit is ∼10 nH, and the short-circuit current amplitude is ∼325kA at ±90kV charging voltage, with a 10%-90% rise time of 110ns. With a low-impedance RPD shorted by an 18-µm-diameter aluminum wire, a quasi-spherical x-ray focal spot with diameter <0.6mm (width of the half-maximum grayscale) and a pulse duration of ∼25ns (half-width of the radiation pulse) is obtained at ±70kV charging voltage, and the imaging resolution excels 10 lp/mm under 1.56× magnification. According to the transmission-absorption x-ray spectrum estimation, the average emitted photon energy is ∼30keV with a distinct peak in the 10-15keV range that corresponds to the L-lines of tungsten, and the total energy of photons >10keV reaches ∼1.16J. The present results show that the device can serve well for the flash radiography diagnosis and potentially as an efficient light source for dynamic x-ray diffraction.

Dynamic diffraction of thermal neutrons in crystals with continuous deformation field

The purpose of the work is to consider the basics of the formation of a diffraction wave field of thermal neutrons in the case of Laue transmission geometry of a limited beam of neutrons in the crystal, taking into account the peculiarities of the interaction of thermal neutrons with a continuously and slowly changing deformation field of the crystal net. The conditions of both diffraction blurring and diffraction contraction (focusing) up to the practical restoration of the original shape of the packet will be studied.An integral form for determining the quasi-amplitudes of diffracted waves within the framework of the original spatially inhomogeneous beams is formulated, based on the constructed functions of the influence of a point source of thermal neutron waves for crystals with a continues deformation field. It has been shown that neutron focusing is effective, which is revealed by a smaller half-width of the focal spot, an increase in the resolving power of the energy spectrum and focusing efficiency.