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Elements of microfluidic systems created by 3D printing offer numerous advantages, such as rapid manufacturing, low cost, and the ability to create complex 3D channel topologies. Their parameters and performance can be quickly adjusted by editing the model loaded into the printer. However, the mechanical properties of polymers used for printing are often poorly documented and can significantly change over time due to aging, relaxation, or creep effects, leading to unexpected behaviour of 3D-printed devices. To address this issue, we performed a complete mechanical characterization of the samples made by 3D printing, including stress relaxation and creep tests, at different time intervals after printing. The determined properties of the material allowed us to model the mechanical and hydrodynamical performance of the 3D-printed microfluidic device, which we demonstrate using an example of a fully printed check valve specially developed for use in microfluidic systems. This approach allows easy quantitative evaluation of the optimal production cycle and lifetime of 3D-printed microfluidic devices. [ABSTRACT FROM AUTHOR]

Infrared spectroscopy (IR) is a widely used technique enabling to identify specific functional groups in the molecule of interest based on their characteristic vibrational modes or the presence of a specific adsorption site based on the characteristic vibrational mode of an adsorbed probe molecule. The interpretation of an IR spectrum is generally carried out within a fingerprint paradigm by comparing the observed spectral features with the features of known references or theoretical calculations. This work demonstrates a method for extracting quantitative structural information beyond this approach by application of machine learning (ML) algorithms. Taking palladium hydride formation as an example, Pd‐H pressure‐composition isotherms are reconstructed using IR data collected in situ in diffuse reflectance using CO molecule as a probe. To the best of the knowledge, this is the first example of the determination of continuous structural descriptors (such as interatomic distance and stoichiometric coefficient) from the fine structure of vibrational spectra, which opens new possibilities of using IR spectra for structural analysis. [ABSTRACT FROM AUTHOR]

Pervaporation is considered the most promising technology for dehydration of bioalcohols, attracting increasing attention as a renewable energy source. In this regard, the development of stable and effective membranes is required. In this study, highly efficient membranes for the enhanced pervaporation dehydration of ethanol were developed by modification of sodium alginate (SA) with a polyethylenimine (PEI) forming polyelectrolyte complex (PEC) and graphene oxide (GO). The effect of modifications with GO or/and PEI on the structure, physicochemical, and transport characteristics of dense membranes was studied. The formation of a PEC by ionic cross-linking and its interaction with GO led to changes in membrane structure, confirmed by spectroscopic and microscopic methods. The physicochemical properties of membranes were investigated by a thermogravimetric analysis, a differential scanning calorimetry, and measurements of contact angles. The theoretical consideration using computational methods showed favorable hydrogen bonding interactions between GO, PEI, and water, which caused improved membrane performance. To increase permeability, supported membranes without treatment and cross-linked were developed by the deposition of a thin dense layer from the optimal PEC/GO (2.5%) composite onto a developed porous substrate from polyacrylonitrile. The cross-linked supported membrane demonstrated more than two times increased permeation flux, higher selectivity (above 99.7 wt.% water in the permeate) and stability for separating diluted mixtures compared to the dense pristine SA membrane. [ABSTRACT FROM AUTHOR]

In this work, the concentration dependencies of unit cell parameters, microstructure, dielectric, impedance spectra, and magnetic properties of (1 – x)SmFeO3–xNaNbO3 were studied for the first time. It was found that at a concentration x = 0.7, the unit cell parameter a, the tilt angles θ and rotation angles φ of oxygen octahedra and the bond lengths Fe-O1 and Fe-O3 of samarium ferrite SmFeO3 (SFO) have a maximum, and Fe-O2 has a minimum value. The tilt angle θ, rotation angle φ of the octahedral, and the bond lengths of sodium niobate NaNbO3 (NNbO) change nonmonotonically. For x = 0.9, the unit cell parameters b and c, as well as all bond lengths in the NaO9 tetradecahedra, reach their minimum values. Anomalies corresponding to the spin-reorientation transition temperatures TSR1 and TSR2 were detected in the dielectric spectra of SFO at temperatures of 200 and 309 °C. The jump in the real part of the dielectric constant ε′(T), starting before – 100 °C, is attributed to the response of the dipole moments to the magnetic moment jump and spin switching (TSSW). Anomalies corresponding to transitions between different phases in this antiferroelectric were found in the temperature dependences of ε′(T) and dielectric loss tangent tgδ(T) of NNbO at temperatures of – 75, 23, 160, 278, 379, and 433 °C. From magnetic measurements, it was found that the composition with x = 0.8 has a minimum size of coherent scattering regions of D = 94 nm, representing the second critical size at which the coercive field Hc reaches its maximum value. [ABSTRACT FROM AUTHOR]

Simple Summary: This review examines the latest technologies using machine learning (ML) methods, including the use of convolutional neural networks, decision trees, and generative adversarial networks to solve problems concerning cancer recognition, planning optimal treatment strategies, as well as predicting the likelihood of patient survival. The authors also discuss the prospects of using machine learning technologies in medicine. In addition, the authors emphasize the need to address issues such as the anonymization of data received from patients. The role of machine learning (a part of artificial intelligence—AI) in the diagnosis and treatment of various types of oncology is steadily increasing. It is expected that the use of AI in oncology will speed up both diagnostic and treatment planning processes. This review describes recent applications of machine learning in oncology, including medical image analysis, treatment planning, patient survival prognosis, and the synthesis of drugs at the point of care. The fast and reliable analysis of medical images is of great importance in the case of fast-flowing forms of cancer. The introduction of ML for the analysis of constantly growing volumes of big data makes it possible to improve the quality of prescribed treatment and patient care. Thus, ML is expected to become an essential technology for medical specialists. The ML model has already improved prognostic prediction for patients compared to traditional staging algorithms. The direct synthesis of the necessary medical substances (small molecule mixtures) at the point of care could also seriously benefit from the application of ML. We further review the main trends in the use of artificial intelligence-based technologies in modern oncology. This review demonstrates the future prospects of using ML tools to make progress in cancer research, as well as in other areas of medicine. Despite growing interest in the use of modern computer technologies in medical practice, a number of unresolved ethical and legal problems remain. In this review, we also discuss the most relevant issues among them. [ABSTRACT FROM AUTHOR]

Grain boundaries (GBs), with their diversity in both structure and structural transitions, play an essential role in tailoring the properties of polycrystalline materials1–5. As a unique GB subset, {112} incoherent twin boundaries (ITBs) are ubiquitous in nanotwinned, face-centred cubic materials6–9. Although multiple ITB configurations and transitions have been reported7,10, their transition mechanisms and impacts on mechanical properties remain largely unexplored, especially in regard to covalent materials. Here we report atomic observations of six ITB configurations and structural transitions in diamond at room temperature, showing a dislocation-mediated mechanism different from metallic systems11,12. The dominant ITBs are asymmetric and less mobile, contributing strongly to continuous hardening in nanotwinned diamond13. The potential driving forces of ITB activities are discussed. Our findings shed new light on GB behaviour in diamond and covalent materials, pointing to a new strategy for development of high-performance, nanotwinned materials.We report atomic observations of six incoherent twin boundary configurations and structural transitions in diamond at room temperature, showing a dislocation-mediated mechanism different from metallic systems and shedding new light on grain boundary behaviour. [ABSTRACT FROM AUTHOR]

The development of artificial intelligence (AI) has revolutionized medical care in recent years and plays a vital role in a number of areas, such as diagnostics and forecasting. In this review, we discuss the most promising areas of AI application to the field of bone tissue engineering and prosthetics, which can drastically benefit from AI-assisted optimization and patient personalization of implants and scaffolds in ways ranging from visualization and real-time monitoring to the implantation cases prediction, thereby leveraging the compromise between specific architecture decisions, material choice, and synthesis procedure. With the emphasized crucial role of accuracy and robustness of developed AI algorithms, especially in bone tissue engineering, it was shown that rigorous validation and testing, demanding large datasets and extensive clinical trials, are essential, and we discuss how through developing multidisciplinary cooperation among biology, chemistry with materials science, and AI, these challenges can be addressed. [ABSTRACT FROM AUTHOR]

Rare-earth-doped nanoscaled BaGdF5 is known as an efficient contrasting agent for X-ray micro-CT and NMR as well as a promising candidate for X-ray photodynamic therapy, thereby opening an opportunity for theragnostic applications. Conventional synthesis of Ln-doped BaGdF5 consider a long-lasting batch procedure, while a conjugation with photosensitizer usually implies a separate stage requiring active mixing. To the best of our knowledge, in this work, we for the first time obtain BaGdF5:Tb3+ nanophosphors in a microfluidic route at temperatures as low as 100 °C while decreasing the time of thermal treatment down to 6 min. The proposed synthesis route allows for the obtaining of single-phase and monodisperse BaGd1−xF5:Tbx3+ nanoparticles with an averaged particle size of ca. 7–9 nm and hydrodynamic radius around 22 nm, as estimated from TEM and DLS, respectively. In addition, X-ray-excited optical luminescence has been recorded in situ for the series of nanophosphors synthesis with varied flow rates of Tb3+ and Gd3+ stock solutions, thereby anticipating a possible application of microfluidics for screening a wide range of possible co-dopants and reaction conditions and its effect on the optical properties of the synthesized materials. Moreover, we demonstrated that BaGd1−xF5:Tbx3+@RoseBengal conjugates might be obtained in a single-stage route by implementing an additional mixer at the synthesis outcome, namely, by mixing the resulting reaction mixture containing nanoparticles with an equivalent flow of photosensitizer aqueous solution. In vitro cytotoxicity test declares moderate toxicity effect on different cell lines, while the results of flow cytometry indirectly confirm cellular uptake. Finally, we report long-term biodistribution monitoring of the synthesized nanocomposites assessed by X-ray micro-CT in the in vivo experiments on balb/c mice, which depicts an unusual character of agents' accumulation. [ABSTRACT FROM AUTHOR]

The xBiFeO3–(1–x)PbZr0.9Ti0.1O3 composites synthesized by the solid-phase reaction were characterized using complex methods to determine their structure and physical properties. According to the results of X-ray diffraction analysis, it was found that the synthesized composites have a rhombohedral perovskite structure with the space symmetry group R3с, and there are no impurities or second phases present in either the ferrite or ferroelectric phases. According to the results of impedance spectroscopy, it was found that the nature of the relaxation in the composites is non-Debye, suggesting a complex conduction mechanism involving multiple relaxation processes. With an increasing proportion of ferroelectric PbZr0.9Ti0.1O3 (PZT) phase, the composites exhibit dual-arc behavior in the Cole-Cole diagrams obtained from the impedance spectroscopy measurements. The dual-arc behavior shows the contribution of both the bulk (grain) and grain boundary to the conduction mechanism in the temperature range of 160–230 °C. The dynamics of the crystal lattice in the composites were studied using optical and FTIR spectroscopy. The magnetization curves M(H) of the composites are characterized by weak ferromagnetism, which is due to the substitution of (Ti/Zr)4+ by Fe3+ in the crystal lattice. This substitution leads to structural distortions and the appearance of ferromagnetic ordering in the composite materials. [ABSTRACT FROM AUTHOR]

Heterometallic FeCo dinuclear complexes on the basis of the redox-active 1,10-phenanthroline-5,6-dione with ancillary bis(pyrazolyl)borate anions and tetradentate N-donor ligands (N,N′-dialkyl-2,11-diaza[3.3]-(2,6)pyridinophane and tris(2-pyridilmethyl)amine derivatives) were studied by the DFT UTPSSh/6–311 + + G(d,p) method in a view to possible spin-crossover (SCO) or valence tautomeric (VT) interconversions. The electronic structures (namely, spin and oxidation states of the electronically labile centers) and magnetic properties of the considered compounds were found to be determined by the position of the outer-sphere PF6– counterion and the type of N-donor base. The most energetically preferred isomers contain a counterion near the cobalt ion. The presence of PF6– next to the iron center stabilizes the ferric state of this metal and the dianionic form of the 1,10-phenanthroline-5,6-dione linker ligand. The variation of the structural peculiarities allowed us revealing the dinuclear complexes prone to exhibit the SCO and VT processes, which makes them promising building blocks of magnetic materials. [ABSTRACT FROM AUTHOR]

A multichannel microfluidic cell (MFC) obtained using 3D printing for studying the structure of complex solutions by small-angle X-ray scattering (SAXS) is described. MFC was tested at the BioMUR beamline of the Kurchatov synchrotron. A comparative analysis of SAXS signal from the standard capillary and from the developed MFC was carried out, with MFC showing significant advantages. The dynamics of SAXS scattering curves for lysozyme solutions with NaCl precipitant were studied when the protein and precipitant concentrations changed. The obtained time series of data are well consistent with the known data for the lysozyme solution. [ABSTRACT FROM AUTHOR]

The present study investigates the concentration dependence of physical properties and structural parameters of YbMn1−хFeхO3 (YbMF) compositions, which were nanostructured using the mechanical activation method at a pressure of 1 GPa. Using X-ray diffraction, the dependence of the unit cell parameters of the H-hexagonal (P63cm) and O-orthorhombic (Pnma) phases on the Fe3+ dopant concentration was studied. It was found for the first time that a morphotropic region (MR) was formed in YbMF in the concentration range x = 0.6–0.8, characterized by the coexistence of H and O-phases. At the point х = 0.5, the minimum values of all bond lengths of the H-phase were observed, while at х = 0.8, the bond length minimum of the YbO8 dodecahedra of the O-phase was observed. The tilt θ° and rotation φ° angles of oxygen octahedra MnO6/FeO6 of the O-phase also vary with the Fe3+ concentration in the range of (19.354–19.754)° and (12.648–12.677)°, respectively. Using the complex impedance method Z* = Z′(ω) − j·Z″ (ω), the study showed that the relaxation character was non-Debye. Theoretical and experimental curves were obtained for each YbMF composition at different temperatures, along with the corresponding equivalent circuits. The study also investigated the parameters of the stochastic magnetic domain structure using the random magnetic anisotropy model. It was found that in the region of solid solutions of YbMF, the values of Hc and Mr have maxima at x = 0.5, and the highest value of Hc, equal to 452 Oe, is inside the MR. [ABSTRACT FROM AUTHOR]

LiCoPO4 is considered the most interesting positive electrode material. Therefore, 4 different percentages of LiCo1 − xFexPO4 were synthesized by a hydrothermal route at low temperatures. The as-prepared sample has a single orthorhombic Pn21a-phase at 220 °C. As a result, the thermodynamics and combustion process were investigated at numerous rates of heating, and the kinetic parameters were calculated using thermogravimetric experiments. Pyrolysis went to the high-temperature region with an increase in intensity in heating rate, according to the TGA study of the combustions. Three stages were determined according to the TGA analysis, and each stage predicted another phase which was confirmed by XRD. The thermodynamics study of LiCo1 − xFexPO4 materials was an efficient technique to investigate the temperature impact on the pyrolysis activity, which may be beneficial in many contemporary applications. The values of Avrami exponent n(χ) calculated in terms of conversion rate dχ/dt of the first, second, and third conversion peak is 2.22 and 2.95 (for different compositions of LiCo1 − xFexPO4 (0 ≤ x ≤ 20)), respectively. The Impedance spectrum shows that the increase in the Fe content improves the electrical conductivity of LiCoPO4. [ABSTRACT FROM AUTHOR]

In this work, the structural phase state and physical properties of YbMn1-xFexO3 (hereinafter YbMF) ceramics in the range of x = 0.0–1.0 with a concentration step Δx = 0.1 were studied by complex methods. X-ray diffraction revealed that the YbMF compositions in the range of x = 0.1–0.5 were hexagonal (H) phase solid solutions. In the concentration range of x = 0.6–0.8, the hexagonal and orthorhombic (O) systems coexist, and the unit cell parameters of these phases rise with increasing x. The study of the lattice parameters, bond lengths, bond angles and the main parameters of the magnetic hysteresis loop of the H-phase revealed the presence of a singular point x = 0.5 in the concentration range, where extrema of the corresponding parameters were observed. By analyzing the Cole–Cole plots for the electric modulus M*(ω), a conclusion was drawn about the thermally activated nature of the dielectric relaxation for each composition with a single relaxation time τ. The magnetodielectric MD(ω) and magnetoresistive MR(ω) coefficients measured in crossed and parallel fields E and H show high values, which reach 1.6% and 50%, respectively, depending on the frequency of the measuring field. [ABSTRACT FROM AUTHOR]

Microfluidic devices have opened new opportunities for functional material chemical synthesis in a few applications. The screening of microfluidic synthesis processes is an urgent task of the experimental process in terms of automation and intellectualization. This study proposes a methodology and software for extracting the morphological and dynamic characteristics of generated monodisperse droplets from video data streams obtained from a digital microscope. For this purpose, the paper considers an approach to generating an extended feature space characterizing the process of droplet generation using a microfluidic device based on the creation of synthetic image datasets. YOLOv7 was used as an algorithm for detecting objects in the images. When training this algorithm, the values in the test dataset mAP@0.5 0.996 were obtained. The algorithms proposed for image processing and analysis implement the basic functionality to extract the morphological and dynamic characteristics of monodisperse droplets in the synthesis process. Laboratory validation and verification of the software demonstrated high results of the identification of key characteristics of the monodisperse droplets generated by the microfluidic device with the average deviation from the real values not exceeding 8%. [ABSTRACT FROM AUTHOR]

The structure and properties of nanoparticles are greatly influenced by the synthesis method and the stabilizer used in their preparation. The paper presents the results of the effect of various stabilizers (gelatin, sodium citrate, sodium borohydride) on the structure, synthesis, and tribotechnical properties of silver nanoparticles. The mechanism of the formation and growth of silver nanoclusters was investigated using quantum-chemical calculations with full optimization of all parameters using the density functional theory (DFT) PBEPBE/Lanl2DZ method. It is shown that the use of organic stabilizers (for example, gelatin) leads to an increase in the stability of stabilized silver clusters. Such systems have greater conformational flexibility and a large number of molecular donor oxygen centres in their composition. The effect of the stabilizer on the structure of the Ag13 silver cluster was revealed in four model systems: gelatin, ammonium chloride NH4Cl, sodium borohydride NaBH4, and trisodium citrate Na3C6H5O (Na3Cit). Silver nanoparticles (AgNPs) obtained by the sonoelectrochemical, citrate, borohydride, and citrate-borohydride method varied in size from nanometers to several tens of nanometers. As a result of tribotechnical tests of lubricants with the obtained silver nanoparticles, a positive effect of stabilized silver clusters was revealed in the composition of lubricant compositions. The best tribotechnical characteristics were shown by lubricating compositions containing AgNPs stabilized with gelatin. It was found that a decrease in the size of gelatin stabilized AgNPs, when added to lubricants, leads to an increase in the tribological properties. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries based on high-voltage cathode materials, such as LiCoPO4, despite being promising in terms of specific power, still suffer from poor cycle life due to the lower stability of common non-aqueous electrolytes at higher voltages. One way to overcome this issue might be decreasing the working potential of the battery by doping LiCoPO4 by Fe, thus reducing electrolyte degradation upon cycling. However, such modification requires a deep understanding of the structural behavior of cathode material upon lithiation/delithiation. Here we used a combination of operando synchrotron-based XRD and XAS to investigate the dynamics of d-metal local atomic structure and charge state upon cycling of LiCo0.5Fe0.5PO4 mixed d-metal olivine cathode material. Principal components analysis (PCA) of XAS data allowed the extraction of spectra of individual phases in the material and their concentrations. For both Co and Fe two components were extracted, they correspond to fully lithiated and delithiated phases of LixMPO4 (where M = Fe, Co). Thus, we were able to track the phase transitions in the material upon charge and discharge and quantitatively analyze the M2+/M3+ electrochemical conversion rate for both Fe and Co. Rietveld's refinement of XRD data allowed us to analyze the changes in the lattice of cathode material and their reversibility upon (de)lithiation during cycling. The calculation of DFT and Bader charge analysis expects the oxygen redox procedure combined with d-metals redox, which supplements iron charge variations and dominates at high voltages when x < 0.75 in LixCoFePO4. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen (H2) production is a promising route for alternative energetics. Understanding structure–activity relationships is a crucial step towards the rational design of photocatalysts, which requires the application of operando spectroscopy under relevant working conditions. We performed an operando investigation on a catalytic system during the photodeposition of Pt on TiO2 and photostimulated H2 production, using simultaneous laboratory X-ray absorption spectroscopy (XAS), UV–Vis spectroscopy, and mass spectrometry. XAS showed a progressive increase in Pt fluorescence for Pt deposited on TiO2 for over an hour, which is correlated with the signal of the produced H2. The final Pt/TiO2 catalyst contained Pt(0) particles. The electronic features corresponding to the Pt4+ species in the UV–Vis spectrum of the solution disappear as soon as UV radiation is applied in the presence of formic acid, which acts as a hole scavenger, resulting in the presence of Pt(0) particles in solution. [ABSTRACT FROM AUTHOR]

This work is the first to study the influence of crystallite sizes and structural defects on the crystal structure and physical properties of bismuth ferrite BiFeO3 (BFO). Rotatable Bridgman anvils were used to generate the structural defects, with the uniaxial pressures ranging from 0.5 to 1 GPa. According to the X-ray diffraction analysis (XRD), the symmetry space group R3c remains unchanged over the entire pressure range. From the results of the complex impedance spectroscopy, it was found that the relaxation has a non-Debye character and the activation energy increased from 1.48 eV to 2.48 eV for the starting and mechanically activated samples at 1 GPa, respectively. The crystal lattice dynamics were studied by optical and FTIR spectroscopies, and it has been found that Eg varied in the range of 2.18–2.33 eV, whereas the force constant showed variation in the range of 2.2–2.4 N/cm, depending on the applied mechanical activation pressure. The magnetization curves M(H) have been described by the law of approach magnetization to saturation (LAS). Also, a possible critical crystallite size of 70 nm has been determined, at which Hc and Mr reach their maximum values. [ABSTRACT FROM AUTHOR]

In this work, the influence of simultaneous action of high pressure and shear deformation (mechanical activation) on the physical properties of synthesized YbFeO3 was studied using complex methods. The formation of crystalline structures of YbFeO3 powders with different concentrations of structural defects was carried out using Bridgman anvils. It was found that during mechanical activation, the tilting angles of FeO6 oxygen octahedra change within the range θ = 12.69–28.45°. Using X-ray diffraction, it was established that the linear unit cell parameters a, b and c change in a consistent manner with changing mechanical activation pressure, while the space-group symmetry D 2 h 16 –Pbnm is preserved. The sizes of the coherent scattering regions (D) decrease by more than 90% at the maximum mechanical activation pressure (1200 MPa). It was found that the mechanical activation pressures of YbFeO3 have a threshold value (800 MPa), above which the dislocation density decreases. According to the results of impedance spectroscopy, the nature of relaxation was found to be non-Debye and the activation energy increased from 0.649 eV for the starting sample to 1.395 eV for the sample mechanically activated sample at 1 GPa. The magnetization curves M(H) were described using the law of approach to magnetic saturation (LAS), and the critical crystallite size (Dcr) was determined to be 50 nm, at which the maximum Hc is observed. The behaviors of the spectroscopic splitting factor (g) and half-width (ΔH) of the electron paramagnetic resonance (EPR) spectrum are analogous to Hc and Mr, however, the maximum ΔH is observed in the range of 50–105 nm, and the g-factor reaches its maximum at particle sizes of 105 nm. [ABSTRACT FROM AUTHOR]

X-ray photodynamic therapy (XPDT) is aimed at the treatment of deep-located malignant tumors thanks to the high penetration depth of X-rays. In XPDT therapy, it is necessary to use materials that effectively absorb X-rays and convert them into visible radiation-nanophosphors. Rare-earth elements, fluorides, in particular, doped BaGdF5, are known to serve as efficient nanophosphor. On the other hand, the particle size of nanophosphors has a crucial impact on biodistribution, cell uptake, and cytotoxicity. In this work, we investigated various Tb:Gd ratios in the range from 0.1 to 0.5 and optimized the terbium content to achieve the maximum luminescence under X-ray excitation. The effect of temperature, composition of the ethylene glycol/water solvent, and the synthesis technique (solvothermal and microwave) on the size of the nanophosphors was explored. It was found that the synthesis techniques and the solvent composition had the greatest influence on the averaged particle size. By varying these two parameters, it is possible to tune the size of the nanophosphor particles, which make them suitable for biomedical applications. [ABSTRACT FROM AUTHOR]

Lead ions are an efficient neurotoxic metal that results in serious disorders for human beings, including poisoning, kidney and liver disorders, hepatitis, anaemia, encephalopathy, and nephritic syndrome. The low-cost and eco-friendly biocomposite from Zea mays sponge (ZMS) biomass encapsulated using Na-alginate in the cross-linked matrix (ZMS/Na-alginate) as a biosorbent. A statistical approach uses full factorial design space to optimize the best conditions for preparation beads. The effect of concentrations (w/v, g/100 mL) of Na-alginate (X1), ZMS biomass (X2), and CaCl2 cross-linker (X3) retesting for Pb(II) ions elimination from the aquatic medium in batch mode. The supreme values optimized for X1, X2, and X3 are relevant to 4.5%, 2.5%, and 1.97%. After optimization using response surface methodology, the maximum lead removal by ZMS/Na-alginate biocomposite was 97.11%. The ZMS/Na-alginate biocomposite was characterized using scanning electron microscopy and attenuated total reflection spectroscopy to investigate physical and chemical modification in the structure during the biosorption system. Therefore, the synthesized ZMS/Na-alginate beads show considerable stability during 5 consecutive adsorption–desorption cycles. This approach study demonstrates that the optimized condition affects the removal of lead ions. The findings support using the modified raw biomass as a potential absorbent for heavy metal ions removal from aqueous media. [ABSTRACT FROM AUTHOR]

Microscopic tissue analysis is the key diagnostic method needed for disease identification and choosing the best treatment regimen. According to the Global Cancer Observatory, approximately two million people are diagnosed with colorectal cancer each year, and an accurate diagnosis requires a significant amount of time and a highly qualified pathologist to decrease the high mortality rate. Recent development of artificial intelligence technologies and scanning microscopy introduced digital pathology into the field of cancer diagnosis by means of the whole-slide image (WSI). In this work, we applied deep learning methods to diagnose six types of colon mucosal lesions using convolutional neural networks (CNNs). As a result, an algorithm for the automatic segmentation of WSIs of colon biopsies was developed, implementing pre-trained, deep convolutional neural networks of the ResNet and EfficientNet architectures. We compared the classical method and one-cycle policy for CNN training and applied both multi-class and multi-label approaches to solve the classification problem. The multi-label approach was superior because some WSI patches may belong to several classes at once or to none of them. Using the standard one-vs-rest approach, we trained multiple binary classifiers. They achieved the receiver operator curve AUC in the range of 0.80–0.96. Other metrics were also calculated, such as accuracy, precision, sensitivity, specificity, negative predictive value, and F1-score. Obtained CNNs can support human pathologists in the diagnostic process and can be extended to other cancers after adding a sufficient amount of labeled data. [ABSTRACT FROM AUTHOR]

In the field of intelligent surface inspection systems, particular attention is paid to decision making problems, based on data from different sensors. The combination of such data helps to make an intelligent decision. In this research, an approach to intelligent decision making based on a data integration strategy to raise awareness of a controlled object is used. In the following article, this approach is considered in the context of reasonable decisions when detecting defects on the surface of welds that arise after the metal pipe welding processes. The main data types were RGB, RGB-D images, and acoustic emission signals. The fusion of such multimodality data, which mimics the eyes and ears of an experienced person through computer vision and digital signal processing, provides more concrete and meaningful information for intelligent decision making. The main results of this study include an overview of the architecture of the system with a detailed description of its parts, methods for acquiring data from various sensors, pseudocodes for data processing algorithms, and an approach to data fusion meant to improve the efficiency of decision making in detecting defects on the surface of various materials. [ABSTRACT FROM AUTHOR]

Glycopolymer materials have emerged as a significant biopolymer class that has piqued the scientific community's attention due to their potential applications. Recently, they have been found to be a unique synthetic biomaterial; glycopolymer materials have also been used for various applications, including direct therapeutic methods, medical adhesives, drug/gene delivery systems, and biosensor applications. Therefore, for the next stage of biomaterial research, it is essential to understand current breakthroughs in glycopolymer-based materials research. This review discusses the most widely utilized synthetic methodologies for glycopolymer-based materials, their properties based on structure–function interactions, and the significance of these materials in biosensing applications, among other topics. When creating glycopolymer materials, contemporary polymerization methods allow precise control over molecular weight, molecular weight distribution, chemical activity, and polymer architecture. This review concludes with a discussion of the challenges and complexities of glycopolymer-based biosensors, in addition to their potential applications in the future. [ABSTRACT FROM AUTHOR]

We have designed, built, and tested two cells for in situ and, potentially, operando X-ray absorption spectroscopy experiments in transmission and fluorescence modes. The cells were developed for high-pressure and high-temperature conditions to study the catalytic processes under relevant industrial conditions. Operation of the cells was tested for Ru and Rh-based homogeneous and heterogeneous catalytic systems. Using synchrotron-based in situ X-ray absorption spectroscopy we tracked the evolution of active metal species during catalytic reactions. Our setup proved that it was capable to investigate liquid-state homogeneous and heterogenous systems under elevated temperatures, high pressures of reactive gasses, and in the presence of corrosive reagents. [ABSTRACT FROM AUTHOR]

A family of ionic ferric catecholate complexes 1–4 bearing a disubstituted 3,6-di-tert-butyl-catecholate ligand (3,6-DBCatH2) and tetradentate tris(2-pyridylmethyl)amine (TPA) was prepared and its spin transitions were investigated. Variation of the outer-sphere counteranions (PF6, BPh4, ClO4, BF4) is accompanied by changes in the magnetic behavior of the compounds under consideration. The crystal structures of complexes 1, 3 and 4 were determined by single crystal X-ray diffraction analysis at 100 K and 293 K. The complexes were characterized by the occurrence of a thermally induced spin-crossover process in the solid state with different degrees of completeness, which was confirmed by the comprehensive spectroscopic investigation (EPR, magnetic susceptibility, Mössbauer, and XAS) of the isolated compounds. Complex 4 containing BF4 anions was found to demonstrate valence tautomeric transition along with spin-crossover. This finding makes compound 4 the first salt-like mononuclear ferric catecholate complex exhibiting valence tautomerism. [ABSTRACT FROM AUTHOR]

In this study, we used density functional theory (DFT) and natural bond orbital (NBO) analysis to determine the structural, electronic, reactivity, and conformational features of 2,5,5-trimethyl-1,3,2-di-heteroatom (X) phosphinane-2-sulfide derivatives (X = O (compound 1), S (compound 2), and Se (compound 3)). We discovered that the features improve dramatically at 6-31G** and B3LYP/6-311+G** levels. The level of theory for the molecular structure was optimized first, followed by the frontier molecular orbital theory development to assess molecular stability and reactivity. Molecular orbital calculations, such as the HOMO–LUMO energy gap and the mapping of molecular electrostatic potential surfaces (MEP), were performed similarly to DFT calculations. In addition, the electrostatic potential of the molecule was used to map the electron density on a surface. In addition to revealing molecules' size and shape distribution, this study also shows the sites on the surface where molecules are most chemically reactive. [ABSTRACT FROM AUTHOR]

As is known from molecular dynamics simulation, lysozyme oligomers in crystallization solutions are most stable when taking into account as many precipitant ions as possible embedded in the corresponding crystal structure. Therefore, the number of precipitant ions associated with crystallographic oligomer models can play a role during the modeling of small-angle X-ray scattering (SAXS) data. This hypothesis has been tested in the present work. As a result, it turned out that the best fit quality to the experimental SAXS data is reached when using oligomers without precipitant ions at all or with embedded chlorine ions. Molecular dynamics (MD) simulation shows that the stability of crystallization oligomers depends on the consideration of anions and cations in oligomer structure. Thus, it is chlorine ions which stabilize dimer and octamers in lysozyme crystallization solution. As SAXS is more sensitive to the role of cations and MD shows the role of anions which are "light" for X-rays, it has been shown that precipitant cations most likely do not bind to monomers, but to already-formed oligomers. [ABSTRACT FROM AUTHOR]

In an article published in Small Methods, Bugaev and co-workers discuss the use of machine learning algorithms to analyze infrared spectra and extract metal-metal interatomic distances in palladium hydride nanoparticles. By using CO as a probe molecule, this approach provides an efficient, cheap, and non-destructive method for characterizing the atomic structure of metal catalysts under in situ and operando conditions. The study highlights the potential of machine learning in providing valuable insights into the structural information of materials. [Extracted from the article]

The attempts to develop efficient methods of solar energy conversion into chemical fuel are ongoing amid climate changes associated with global warming. Photo-electrocatalytic (PEC) water splitting and CO2 reduction reactions show high potential to tackle this challenge. However, the development of economically feasible solutions of PEC solar energy conversion requires novel efficient and stable earth-abundant nanostructured materials. The latter are hardly available without detailed understanding of the local atomic and electronic structure dynamics and mechanisms of the processes occurring during chemical reactions on the catalyst–electrolyte interface. This review considers recent efforts to study photo-electrocatalytic reactions using in situ and operando synchrotron spectroscopies. Particular attention is paid to the operando reaction mechanisms, which were established using X-ray Absorption (XAS) and X-ray Photoelectron (XPS) Spectroscopies. Operando cells that are needed to perform such experiments on synchrotron are covered. Classical and modern theoretical approaches to extract structural information from X-ray Absorption Near-Edge Structure (XANES) spectra are discussed. [ABSTRACT FROM AUTHOR]

Ordered amorphous carbon clusters (OACC) transformed from m-xylene solvated C60 (C60·m-xylene) are known as the first crystalline material constructed from amorphous building blocks and have attracted a lot of attention. The formation mechanism and physical properties of this material are of great importance for the design of more materials with such structural characteristics. In this article, the transport and structural properties of C60·m-xylene are systematically investigated under pressure using impedance spectroscopy, four-probe resistance measurements, and Raman spectroscopy. It is found that C60·m-xylene is an insulator at ambient pressure. The resistance decreases sharply starting at the pressure around 8 GPa due to the pressure-induced dimerization of C60 verified by the Raman study. The presence of solvent hinders further polymerization of C60 under higher pressures. The temperature-dependence of resistance exhibits a semiconducting characteristic at > 8–26.9 GPa, and is well described by Mott's three-dimensional variable-range hopping model (3D-VRH), indicating an insulating-to-semiconducting transition accompanied with pressure-induced dimerization. The resistance and hopping energy are both found to decrease monotonically with pressure and reach the minimum near 24 GPa. Above the pressure, resistance and hopping energy values start to rise, suggesting a transition to another semiconducting state, which is attributed to the pressure-induced formation of OACC. The conductivity shows a large hysteresis during decompression from higher than 24 GPa, confirming a different transport behavior of the sample with retained fullerenes versus OACC. The findings of our study suggest that the transport property of fullerene is tunable by introducing solvates and further enhance our understanding of the OACC. [ABSTRACT FROM AUTHOR]

This study investigated the effect of boron-doped and undoped diamond coatings on the cutting performance of cobalt cemented tungsten carbide (WC-Co) drills when drilling CFRP. Three types of diamond coating, as boron-doped microcrystalline (B-MCD), boron-doped nanocrystalline (B-NCD), and undoped nanocrystalline (NCD), were deposited on specially designed for drilling of CFRP one-shot drills by the hot filament chemical vapor deposition (HFCVD) method. The coating characteristics, such as surface morphology, roughness, carbon structure, and interfacial adhesion, were investigated. Then cutting tests were carried out, and the tool's flank wear, thrust force, and torque were evaluated. For comparison of cutting performance, non-coated WC-Co drills were used in the tests as well. Furthermore, drilled holes were inspected in terms of peel-up and push-out delamination. According to the results, the B-MCD coated drill presented advantages in tool life, and quality of drilled holes over the NCD and B-NCD coated drills. Also, the results confirmed the adhesion enhanced effect of diamond coating to WC-Co substrate through boron doping of the layer. [ABSTRACT FROM AUTHOR]

In this work, the structure and physical properties of (1 − x)(CoFe2O4) − x(PbTiO3) compositions, synthesized by the solid-phase method, were studied for the first time using complex methods. It was found that the solid-phase sintering of the inverse spinel CoFe2O4 (CFO) and the ferroelectric PbTiO3 (PTO) is frequently accompanied by the formation of additional phases—hexaferrite PbFe12O19 (PFO) and solid solutions, which were identified by X-ray diffraction, energy-dispersive X-ray analysis, and Raman spectroscopy. The dependencies of the unit cell parameters of the main components and additional phases on the concentration of PTO were studied at room temperature. The concentration interval (x = 0.3–0.7) with extreme values of structural parameters and non-monotonic changes of the physical properties was discovered. Complex quantities such as dielectric permittivity ɛ*(ω) and electric modulus M*(ω) were studied over a wide range of frequencies and temperatures using dielectric spectroscopy. The polarization switching kinetics of (1 − x)(CFO) − x(PTO) compositions were studied, and the saturated ferroelectric hysteresis loops P(E) with maximum spontaneous polarization Ps equal to 132 μC/cm2 were obtained for the first time. The bandgap Eg was determined by optical absorption spectroscopy at room temperature; Eg varies depending on the PTO concentration in the range 2.11–2.57 eV. The dynamic properties of the compositions were studied by Fourier transform infrared spectrometer (FTIR) and Raman spectroscopy. The Raman modes corresponding to PFO are well detected starting from compositions 0.3(CFO)–0.7(PTO). [ABSTRACT FROM AUTHOR]

This paper was the first to present the results of studying the influence of structural defects on the physical properties of pre-synthesized ytterbium iron garnet (YbIG). The concentration and type of structural defects were controlled by mechanically activating the powders using Bridgman anvils. Using scanning electron microscopy and X-ray diffraction (XRD), it was revealed that the particle morphology, the unit cell parameters, mean size of the coherent scattering regions (D ) and microstrains ( Δ d / d ) vary in a wide range. Using optical spectroscopy, XRD and FTIR to study the dynamic properties of the crystal lattice, showing that the bandgap and force constants of dodecahedral-coordinated ytterbium (Yb–O)d and octahedral-coordinated iron (Fe–O)o change non-monotonically with decreasing crystallite size. By analyzing the dependence of the magnetic hysteresis loop M (H) on the crystallite size D , it was concluded that there was a critical crystallite size ( D crit = 75 nm) of YbIG, at which the coercive force H c has a maximum value. For the first time, changes in g-factor and the half-width Δ H of the electron paramagnetic resonance (EPR) spectra of nanoscale crystallites were found to be correlated with the parameters of the magnetic hysteresis loop M (H) . [ABSTRACT FROM AUTHOR]

Coal slurry is an essential component of mining operations, accounting for more than half of operating costs. Dewatering technology is simultaneously confronted with obstacles and possibilities, and it may yet be improved as the crucial step for reducing the ultimate processing cost. Coagulation/flocculation is used as a dewatering process that is reasonably cost-effective and user-friendly. This paper reviews application of different coagulants/flocculants and their combinations in dewatering mechanisms. In this context, various polymeric flocculants are discussed in the coal slurry in depth. Many operational parameters that influence the performance of coal slurry flocculation are also presented. Furthermore, a discussion is provided on the mechanism of flocculants' interaction, the strategy of combining flocculants, and efficient selection methods of flocculants. Finally, coagulation/flocculation remaining challenges and technological improvements for the better development of highly efficient treatment methods were highlighted, focusing on the intricate composition of slurry and its treatment difficulties. [ABSTRACT FROM AUTHOR]

In recent years, CVD diamond-coated tungsten carbide (WC-Co) tools have been widely utilized due to their benefits in the machining of non-ferrous alloys and polymer composite materials, especially carbon-fiber-reinforced plastics (CFRPs). The reconditioning of such coated tools is economically attractive due to their high cost and short tool life. The decoating of the remaining diamond film from the used tools and the subsequent surface preparation by wet chemical pretreatment are essential steps for new CVD diamond film formation. Previously, it was shown that reactive ion beam etching (RIBE) could effectively remove CVD diamond films. However, some degree of WC-Co tool substrate damage is expected due to the high ion energy in RIBE and the chemical activity in wet etching. This study addresses the effects of RIBE decoating and surface pretreatment steps on WC-Co tools with a complex shape in terms of the ion-induced surface damage, geometry alteration, and adhesion of a subsequently re-applied CVD diamond film. Moreover, the cutting performance of the tools subjected to the RIBE decoating and repeated film deposition was studied via CFRP cutting tests. It has been shown that the RIBE decoated and recoated tools had a high level of cutting performance comparable to the new tools. [ABSTRACT FROM AUTHOR]

Modeling metal sorption in soils is of great importance to predict the fate of heavy metals and to assess the actual risk driven from pollution. The present study focuses on adsorption of HM ions on two types of hydromorphic soils, including calcaric fluvisols loamic and calcaric fluvic arenosols. The individual and competitive adsorption behaviors of Cu and Zn on soils and soil constituents are evaluated comprehensively. It is established that the sorption processes were best described with the Langmuir model. The results suggest that the calcaric fluvic arenosols are more vulnerable to heavy metal input compared to fluvisols loamic. In all cases, Cu had a higher range of values of the adsorption process parameters relative to Zn. The Zn is likely to be the most critical environmental factor in such soils since it exhibited a decreased sorption under competitive conditions. The retention mechanisms of HM in hydromorphic soils are considered. Based on theoretical calculations of ion activity in soil solutions using solubility diagrams of Cu and Zn compounds, the possibility of precipitation of Cu hydroxide and Zn carbonate in the studied soils is shown. Direct physical methods of nondestructive testing (XAFS and XRD) are applied to experimentally prove the formation of these HM compounds on the surface of montmorillonite, the dominant mineral in hydromorphic soils, and calcite. Thus, the combination of both physicochemical methods and direct physical methods can provide a large amount of real information about the mechanisms of HM retain with solid phases. [ABSTRACT FROM AUTHOR]

Low-toxic colloidal superparamagnetic iron oxide nanoparticles (SPIONs) for theranostic applications were obtained by microwave-assisted technique. Nanoparticles were synthesized by the hydrothermal method under different conditions. XANES, XRD, and XPS studies support the maghemite (γ-Fe2O3) atomic and electronic structure of the nanoparticles. XANES data analysis reveals that nanoparticles have the structure reminiscent of the macroscopic maghemite. Mossbauer spectroscopy supports the γ-Fe2O3 phase of the nanoparticles and vibration magnetometry study shows that the nanoparticles appear to be superparamagnetic. Nanoparticle shape and size were studied by TEM and DLS methods. It was shown that the nanoparticles do not exceed 20 nm. Also, the nanoparticles are found to be low-toxic and did not have significant effects on the viability of the HeLa cell culture. The obtained nanoparticles generated heat with the highest ILP value of 2.56 nHm2/kg and can be considered potential candidates as heat mediators for local magnetic hyperthermia in oncology. [ABSTRACT FROM AUTHOR]

In the present study, the biochar derived from sunflower husks was used as a mediator in the heterogeneous Fenton process. The physical and chemical characteristics were studied in terms of specific surface area, elemental contents, surface morphology, surface functional groups, thermal stability, and X-ray crystallography. The main aim was to evaluate the effectiveness of biochar in a heterogeneous Fenton process catalyzed by hematite toward the degradation of benzo[a]pyrene (BaP) in Haplic Chernozem. The Fenton-like reaction was performed at a pH of 7.8 without pH adjustment in chernozem soil. The effects of operating parameters, such as hematite dosage and H2O2 concentrations, were investigated with respect to the removal efficiency of BaP. The overall degradation of 65% was observed at the optimized conditions where 2 mg g−1 hematite and 1.25 M H2O2 corresponded to the H2O2 to Fe ratio of 22:1. Moreover, the biochar amendment showed an increment in the removal efficiency and promotion in the growth of spring barley (Hordeum sativum distichum). The BaP removal was reached 75 and 95% after 2.5 and 5% w/w addition of biochar, respectively. The results suggested that the Fenton-like reaction's effectiveness would be greatly enhanced by the ability of biochar for activation of H2O2 and ejection of the electron to reduce Fe(III) to Fe(II). Finally, the presence of biochar could enhance the soil physicochemical properties, as evidenced by the better growth of Hordeum sativum distichum compared to the soil without biochar. These promising results open up new opportunities toward the application of a modified Fenton reaction with biochar for remediating BaP-polluted soils. [ABSTRACT FROM AUTHOR]

Carbon is one of the most fascinating elements due to its structurally diverse allotropic forms stemming from its bonding varieties (sp , sp 2 and sp 3). Exploring new forms of carbon has been the eternal theme of scientific research. Herein, we report on amorphous (AM) carbon materials with a high fraction of sp 3 bonding recovered from compression of fullerene C60 under high pressure and high temperature, previously unexplored. Analysis of photoluminescence and absorption spectra demonstrates that they are semiconducting with a bandgap range of 1.5–2.2 eV, comparable to that of widely used AM silicon. Comprehensive mechanical tests demonstrate that synthesized AM-III carbon is the hardest and strongest AM material known to date, and can scratch diamond crystal and approach its strength. The produced AM carbon materials combine outstanding mechanical and electronic properties, and may potentially be used in photovoltaic applications that require ultrahigh strength and wear resistance. [ABSTRACT FROM AUTHOR]

The ability to control the target physical properties of functional materials without changing stoichiometry and doping is one of the tasks of physical materials science. This work is the first to study the influence of structural defects generated under a force action combined with shear deformation (mechanical activation) on the crystal structure and physical properties of PbZr0.7Ti0.3O3 solid solution. Bridgman's anvils were used to generate structural defects. The symmetry of PbZr0.7Ti0.3O3 was best described by the space group R3m. It was found that PbZr0.7Ti0.3O3 is characterized by a non-monotonic change in the unit cell parameters (a and α) of the dislocation density (ρD) with an increase in the mechanical activation pressure. By measuring the sizes of coherent scattering regions (D) and microstrains (Δd/d), it was found that at a mechanical activation pressure of 120 MPa, a recrystallization process develops in mechanically activated powders, leading to the "healing" of the crystal structure. It is shown that by choosing the mechanical activation pressure, one can control the temperature Tm of the maximum of the dielectric permittivity εm within ΔTm = 11 °C, the Weiss constant CW, and the degree of change in the first-order phase transition. The microstructure of the compositions was studied using SEM, the dynamics of the crystal lattice were studied by X-ray diffraction analysis, optical absorption and FTIR-spectroscopy, where the controlled parameters were the root-mean-square static displacements U ¯ s 2 , the bandgap Eg and the force constants k . It was found that with a change in the pressure of mechanical activation, Eg changes nonmonotonically within the range of 3.21–3.37 eV. [ABSTRACT FROM AUTHOR]

Micro X‐ray fluorescence (XRF) analysis, scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), X‐ray diffraction (XRD), and Mössbauer and X‐ray absorption near‐edge structure (XANES) spectroscopies have been used to study the element and phase composition, and Fe and Ni oxidation states in ordinary chondrites. The meteorites have been initially classified as Markovka (H4 type), Polujamki (H4 type), Sayh al Uhaymir (SaU) 001 (L5 type), Dhofar (Dho) 020 (H4/5 type), and Jiddat al Harasis (JaH) 055 (L4‐5 type). We have applied a set of spectroscopic methods to characterize and quantify the differences between samples. While the concentration of Fe in the meteorites is in agreement with the qualitative assignment of their types (L or H) made upon discovery, we observed extremely low Mg/Si and Al/Si values compared to the data published by Palme et al. (2014). Phase content of the meteorites has been studied by means of XRD, as well as by SEM and EDX. Mössbauer spectroscopy of Fe‐containing phases has determined that Fe ions are present mainly in olivine and pyroxene phases in all studied samples. Goethite, hematite, and troilite phases were found in Markovka, Polujamki, and Sayh al Uhaymir 001, respectively. Markovka and Polujamki samples contained the largest concentration of Fe‐Ni‐Co metal grains. Fe and Ni K‐XANES spectra were analyzed to estimate metal oxidation state in the chondrites and compared with the Mössbauer data. The multispectral data acquired in the present work are of importance for further understanding of meteoritic processes. [ABSTRACT FROM AUTHOR]

Recently our work exhibited the influence of Zirconium oxide on the linear and non-linear optical properties of Sodium silicate glass. The optical constants were computed by Kramer-Kroing relation based on the reflectance spectra, which measured in typical mode spectra by the spectrometer ranging from 200 to 1000 nm. The refractive index, n, was reduced by an increase in the concentrations of ZrO2, while the extinction coefficient, k, was increased. The real and imaginary dielectric constants were calculated. Based on the Miller's equation, the non-linear optical properties were computed and decreased with an increase in zirconium oxide concentration, which implied that an important factor for controlling the optical properties of Sodium silicate glass which useful to utilize in several photonic applications. XRD studied structural properties. [ABSTRACT FROM AUTHOR]

Palladium-based catalysts are exploited on an industrial scale for the selective hydrogenation of hydrocarbons. The formation of palladium carbide and hydride phases under reaction conditions changes the catalytic properties of the material, which points to the importance of operando characterization for determining the relation between the relative fractions of the two phases and the catalyst performance. We present a combined time-resolved characterization by X-ray absorption spectroscopy (in both near-edge and extended regions) and X-ray diffraction of a working palladium-based catalyst during the hydrogenation of ethylene in a wide range of partial pressures of ethylene and hydrogen. Synergistic coupling of multiple techniques allowed us to follow the structural evolution of the palladium lattice as well as the transitions between the metallic, hydride and carbide phases of palladium. The nanometric dimensions of the particles resulted in the considerable contribution of both surface and bulk carbides to the X-ray absorption spectra. During the reaction, palladium carbide is formed, which does not lead to a loss of activity. Unusual contraction of the unit cell parameter of the palladium lattice in the spent catalyst was observed upon increasing hydrogen partial pressure. [ABSTRACT FROM AUTHOR]

X‐ray absorption spectroscopy (XAS) was used to characterize the structure of the photoactive Co(II) azobenzene complex. Optical absorption spectra show that photoinduced changes occur only in dimethylformamide (DMF) solvent, while in acetonitrile, this complex is photochemically inactive. Co K‐edge XAS spectra indicate 6‐coordinated species in acetonitrile with a structure similar to one in the crystalline form of the complex. However, in DMF, an activation process occurs related to the decrease of coordination number, bond shortening and absorption edge shift to the higher energies. Quantitative analysis indicates that observed spectral changes are related to the high spin ‐ low spin transition in the Co complex accompanied by the bond dissociation and solvent coordination. [ABSTRACT FROM AUTHOR]

A key factor that determines the mechanical and electrical performance of graphene-based materials and devices is how graphene behaves under extreme conditions, yet the response of few-layer graphene to high shear stress has not been investigated experimentally. Here we applied high pressure and shear to graphene powder using a rotational diamond anvil cell and studied the recovered sample with multiple means of characterization. Sustaining high pressure and shear, graphene breaks into nanometer-long clusters with generation of large number of defects. At a certain stress level, it transforms to amorphous state and carbon onions. The reduction of infrared reflectivity in the severely sheared phase indicates the decrease in conductivity. Our results unveil the shear sensitive nature of graphene, point out the effects of shear on its physical properties, and provide a potential method to manipulate this promising material. [ABSTRACT FROM AUTHOR]

Palladium-based catalysts are exploited on an industrial scale for the selective hydrogenation of hydrocarbons. The formation of palladium carbide and hydride phases under reaction conditions changes the catalytic properties of the material, which points to the importance of operando characterization for determining the relation between the relative fractions of the two phases and the catalyst performance. We present a combined time-resolved characterization by X-ray absorption spectroscopy (in both near-edge and extended regions) and X-ray diffraction of a working palladium-based catalyst during the hydrogenation of ethylene in a wide range of partial pressures of ethylene and hydrogen. Synergistic coupling of multiple techniques allowed us to follow the structural evolution of the palladium lattice as well as the transitions between the metallic, hydride and carbide phases of palladium. The nanometric dimensions of the particles resulted in the considerable contribution of both surface and bulk carbides to the X-ray absorption spectra. During the reaction, palladium carbide is formed, which does not lead to a loss of activity. Unusual contraction of the unit cell parameter of the palladium lattice in the spent catalyst was observed upon increasing hydrogen partial pressure. [ABSTRACT FROM AUTHOR]

Metal speciation, linked directly to bioaccessibility and lability, is a key to be considered when assessing associated human and environmental health risks originated from anthropogenic activities. To identify the Zn and Cu speciation in the highly contaminated, technogenically transformed soils (Technosol) from the impact zone near the industrial sludge reservoirs of chemical plant (Siverskyi Donets River floodplain, southern Russia), the validity of the BCR sequential extraction procedure using the X-ray absorption fine-structure and X-ray powder diffraction (XRD) analyses was examined after each of the three stages. After the removal of exchange and carbonate-bonded Zn and Cu compounds from Technosol (first stage of extraction), the resulting residual soil showed enrichment in a great diversity of metal compounds, primarily with Me–S and Me–O bonds. The number of compounds with a higher solubility decreased at the subsequent stages of extraction. In the residual soil left over after extracting the first and second fractions, the dominant Zn–S bond appeared as würtzite (hexagonal ZnS) that made up more than 50%, while the Cu–S bond was almost completely represented only by chalcocite (Cu2S). The XRD analysis revealed the authigenic minerals of metals with S: sphalerite (cubic ZnS), würtzite (hexagonal ZnS), covellite (CuS) and bornite (Cu5FeS4). The scanning electron microscopy data confirmed that würtzite was the dominant form of Me with sulfur-containing and carbonate-containing minerals. The Zn–S bond was the main component (57%), whereas the Cu–O bond was dominant in the residual fraction (the fraction after the third-stage extraction). The results revealed that the composition of the residual fractions might include some of the most stable and hard-to-recover metal compounds of technogenic origin. Thus, the application of the novel instrumental methods, coupled with the chemical fractionation, revealed the incomplete selectivity of the extractants in the extraction of Zn and Cu in long-term highly contaminated soils. [ABSTRACT FROM AUTHOR]