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We present an effective model of "space-coiled metacrystals"" composed of a periodic array of sound rigid blocks into which long slots have been coiled up. The periodic cell of the block contains a coiled slot whose straight parts are at wavelength scale, which enables the appearance of Bragg resonances. These resonances, which prevent high transmission, compete with the Fabry--P\'erot resonances of the entire slot, which foster perfect transmission. This results in complex scattering properties driven by the characteristics of the turning regions that act as atoms in a onedimensional coiled crystal. Using appropriate scaling and combining two-scale homogenization with matched asymptotic techniques, the modeling of such metacrystals is proposed. The resulting model is validated through a comparison with full-wave numerics in both harmonic and transient regimes. [ABSTRACT FROM AUTHOR]

An erbium-doped β -GaLaS3 crystal has been grown by the solution-melt method, and the effect of γ -irradiation on their vibrational and radiative properties has been investigated. Experiments have demonstrated that the crystal is transparent in the near and mid-infrared (IR) regions (transparency ∼62% in the range of 350–7100 cm−1), which allows it to be used as an effective matrix for creating lasers in this spectral range. For the first time, the vibrational spectrum of the crystal and the density of phonon states have been calculated using the density-functional theory (DFT) method. Both the original and γ -irradiated β -GaLaS3:Er crystals were investigated by Raman and IR spectroscopy. It has been established that irradiation with a dose of up to 5000 Gray does not lead to structural changes in the crystals. The effect of the formed defects is more clearly manifested in the IR reflection spectra, compared to the Raman spectra. The mechanism of the occurrence of excited states and the emission of Er ions embedded in the lattice has been established, and the effect of γ -irradiation on the radiative properties of β -GaLaS3:Er due to the occurrence of radiation-induced defects has been analyzed. A model has been constructed that explains the Stokes and anti-Stokes radiation of the erbium ions in the crystal. It has been demonstrated that the grown crystal has good prospects for sensor and laser technology of the near and mid-IR ranges due to relatively high values of optical transparency and the intense radiative capacity of the erbium ions. [ABSTRACT FROM AUTHOR]

Kidney stone disease ranks as the world's third most prevalent urological condition, described by the formation of crystalline deposits within the urinary system due to dissolved minerals in the urine. These stone formations can be excruciatingly painful, causing urinary flow obstruction, urinary tract infections, swollen kidneys (hydronephrosis), excessive bleeding, and sometimes necessitate surgical intervention for their removal or fragmentation. While treatments like extracorporeal shock wave lithotripsy (ESWL) and pharmacotherapy are available, their utilization is limited due to high costs, the risk of residual stone fragments post-ESWL, and associated adverse effects such as acute kidney damage, impaired renal function, and increased stone recurrence. Recent studies have highlighted the potential role of plant-derived bioactive compounds, including polyphenols, flavonoids, phenolic acids, terpenes, and alkaloids, in the prevention and treatment of kidney stones. These phytochemicals exhibit diverse mechanisms such as diuretic properties, antioxidant effects, anti-inflammatory actions, inhibition of crystallization and aggregation, reduction of hyperoxaluria, diminishing stone size, and lowering urinary supersaturation. This paper aims to delve into the discussion of these anti-lithiatic phytochemicals and elucidate the mechanisms by which they function in preventing and treating kidney stones. [ABSTRACT FROM AUTHOR]

The simplest method for changing and improving the dielectric properties of crystals involves introducing various substitutional impurities or subjecting the crystals to external infiuences. This allows us to uncover the potential for expanding the practical applications of crystals as optical filters, acousto-optic modulators, temperature and pressure sensors, piezo transducers, scintillators, etc. Currently, the effect of manganese admixture on the dielectric parameters of K2SO4 crystals remains unstudied. Therefore, the objective of this work is to investigate the effect of introducing a manganese admixture into potassium sulfate crystals on their band-energy and refractive properties. In this study, a potassium sulfate crystal with a manganese admixture was synthesized, and its crystal structure was determined. The dispersion of refractive indices was investigated, and the band-energy structure was calculated. It was established that the crystal structure of K2SO4 impurity crystals can be considered a result of multiple heterovalent replacement of two K+ atoms by one Mn2+ atom in the framework of stacking of SO2− 4 tetrahedra. The study reveals that the conduction band's bottom is formed by s- and p-states of sulfur and potassium atoms, while the valence band's top is formed by pstates of oxygen and s-states of oxygen. The manganese impurity in the density of states of the potassium sulfate crystal is represented by a narrow intense d-electron peak, which corresponds to impurity levels in the band gap near the top of the valence band. The calculated band gap for the impurity crystal is Eg = 5.92 eV. It was found that the introduction of the admixture results in a reduction in the volume of the unit cell and a decrease in the refractive indices for three crystal physical directions, with an average decrease of 1.9 × 10−3 . Additionally, it causes a shift in the position of the centers of ultraviolet oscillators in the long-wavelength spectrum region, leading to a decrease in the strength of the corresponding oscillators and electronic polarizability compared to pure crystals. [ABSTRACT FROM AUTHOR]

Gout, calcium pyrophosphate deposition disease, and apatite calcifications, the three main crystal disorders, may involve the spine. These disorders can be completely asymptomatic or associated with various clinical symptoms, such as acute flares and more chronic manifestations. This article presents the typical and more unusual imaging features encountered in these disorders. [ABSTRACT FROM AUTHOR]

Scanning electron microscopy (SEM) and energy dispersive X‐ray (EDX) are powerful tools to study the ultrastructure of numerous specimens and to determine their elemental composition, respectively. However, results have not yet been reported on their application to urine samples in routine clinical laboratory practice. Herein we investigate urine sediment by using SEM and EDX to detect and identify different urine components. A total of 206 urine samples from patients with and without urinary tract infections were analyzed using SEM and EDX. Microorganisms, crystals, epithelial cells, leukocytes, and erythrocytes were targeted in urine sediment samples. The identification of urine components was based on their morphology, size, contrast, and elemental composition. SEM‐analysis allowed us to identify and classify microorganisms in urine sediments into the categories of gram‐negative bacilli, cluster cocci, chain cocci, gram‐negative bacilli, gram‐positive bacilli, and yeasts. In addition, various types of epithelial cells such as renal, transitional, and squamous epithelial cells were found. Furthermore, leukocytes and erythrocytes were well identified, with the detection of various morphological forms of erythrocytes, such as dysmorphic and isomorphic erythrocytes. Using SEM–EDX analysis, calcium oxalate was the most frequently‐identified crystal (92.0%), with prominent peaks of C, O, and Ca elements, followed by struvite (6%), with peaks of Mg, P, O, and N. These preliminary data suggest that the two complementary SEM–EDX analyses can be used to detect and identify microorganisms and crystals in urine samples. Further studies are still needed to apply SEM–EDX to urine sediment analysis. SEM–EDX analyses provided comparative results with the routine results, with accurate identification, high resolution and deep focus compared to the routine urinalysisSEM‐analysis allowed us to identify and classify microorganisms in urine sediments into the categories of gram‐negative bacilli, cluster cocci, chain cocci, gram‐negative bacilli, gram‐positive bacilli and yeasts.SEM–EDX analysis enabled the accurate identification of crystals based on both morphology and elemental composition. [ABSTRACT FROM AUTHOR]

The set of finite binary matrices of a given size is known to carry a finite type A bicrystal structure.We first review this classical construction, explain how it yields a short proof of the equality between Kostka polynomials and one-dimensional sums together with a natural generalisation of the 2M -- X Pitman transform. Next, we show that, once the relevant formalism on families of infinite binary matrices is introduced, this is a particular case of a much more general phenomenon. Each such family of matrices is proved to be endowed with Kac--Moody bicrystal and tricrystal structures defined from the classical root systems. Moreover, we give an explicit decomposition of these multicrystals, reminiscent of the decomposition of characters yielding the Cauchy identities. [ABSTRACT FROM AUTHOR]

The eighth annual international G-CAN research symposium was held in Alexandria, VA on 21st and 22nd October 2022. This hybrid meeting, live face-to-face and virtual live symposium, was attended by over 150 participants. Over 20 research abstract submissions were received from early-career investigators, for plenary oral and poster presentations. Here, we present the accepted, lightly-edited abstracts from the presenters consenting to have their materials published. We thank and congratulate the presenters for their work and contributions to the meeting. [ABSTRACT FROM AUTHOR]

Ceramic ZnO-SnO2-Fe2O3 powders and transparent coatings on glasses prepared using the non-isothermal polymer-salt method demonstrate a strong ability to generate chemically active oxygen species under UV and visible irradiation. Crystal structures and morphologies of these materials were studied using the XRD and the SEM analysis. It was found that there are significant differences in the crystal structure of ceramic powders and thin coatings. The powders consist of randomly oriented oxide nanocrystals of size ~47 nm. The strong orientation of the ZnO nanocrystals due to their interaction with the glass substrate is observed in the coating structure. Experimental data show that thin ceramic coatings are transparent (~90%) in the visible spectral range and the band gap of the ceramic material is 3.44 eV. The band gap value of this multi-component ceramic material is described sufficiently using Verlag’s law. Ceramic powders and coatings demonstrate the intensive photogeneration of reactive oxygen species, both in liquid and air. High photocatalytic activity of ZnO-SnO2-Fe2O3 ceramic coatings and powders was observed upon the oxidation of the diazo dye, Chicago Sky Blue. In the presence of transparent photocatalytic coating, the value of the constant rate of the dye photodecomposition was high (k = 0.056 min−1). It was found that, in spite of their short life time, photogenerated reactive oxygen species demonstrate the ability to decompose dye molecules located up to a distance of 0.5 mm from the surface of ceramic coating. Obtained experimental results suggest that the prepared ceramic materials are promising for different practical applications of the photocatalytic materials.

Abstract X‐ray diffraction from a solid crystal shows the wave nature of photons. It is an important electromagnetic (EM) physics process when X‐ray photons interact with a crystal. Bragg diffraction, often called Bragg reflection, is a special case of the general form of X‐ray diffraction, known as Laue diffraction. When the Bragg's law is met, the incident photon beam is reflected from the crystal plane behaving as a specular reflection at the Bragg angle. However, the Bragg reflection physical process has not been integrated into the general‐purpose Monte Carlo simulation toolkit Geant4 for particle physics. In the current study, we developed a new EM physical process class “G4CrystalBraggReflection” and a new EM physical model class “G4DarwinDynamicalModel” for modeling the Bragg reflection physical process within a crystal. We added the Bragg reflection physical process to the EM physics category of Geant4. The preliminary results of photon tracking in a silicon crystal slab have shown the feasibility of simulating the Bragg reflection process in addition to the standard EM processes in the framework of Geant4.

The conformation of tetrahydrofuran (THF) molecules in vapor has been the subject of considerable computational and experimental studies, the most recent by Park and Kwon stated that the difference between the most stable, twisted C2 conformer and the bent Cs conformer is 17 ± 15 cm−1. Because of low symmetry, all modes from both conformers are allowed in the Raman and infrared spectra. In 1982, Aleksanyan and Antipov observed the emergence of two Raman bands at 249 and 303 cm−1 at 20 K, while only one band at 293 cm−1 was present in solid THF at 142. They assigned the 249 cm−1 band to the restricted pseudorotational motion of THF in the solid state, because on heating, the band diminishes and is too weak to be observed near melting point (at 142 K). Cadioli et al. reported a study of the vibrational spectrum of tetrahydrofuran, giving a complete assignment of all bands including those present in the low-temperature Raman spectrum at 85 K and infrared bands observed at 90 K. They assigned the band at 242 cm−1 in the Raman spectrum at 85 K as an overtone of the lowest normal mode (pseudorotational mode), while the 299 cm−1 band in the same spectrum was assigned as a radial mode. In the following, low-temperature Raman spectra of solid THF together with the Raman matrix isolated spectrum of THF in air will be presented and compared to published data. Our results indicate that the band observed at 245 cm−1 at 10 K is too strong to be assigned as an overtone, since its intensity is of the same magnitude as the 299 cm−1 band.

To investigate the influence of the crosslinked polyethylene (XLPE) structure on electrical performance, various analytical methods were employed to study polyethylene structures with different degrees of crosslinking. Dynamic rheological analysis was conducted to determine material shear viscosity, dynamic viscosity, storage modulus (G′), loss modulus (G″), and other rheological parameters. Additionally, the electrical performance of the material was analyzed by studying the phenomenon of space charge accumulation under direct current voltage. The results indicate that with an increasing mass fraction of the crosslinking agent, the crosslink density of crosslinked polyethylene initially increases and then decreases. When the dicumyl peroxide (DCP) content exceeds 1.0 wt.%, there is an accumulation of like-polarity space charges. The best rheological processing performance of crosslinked polyethylene is observed when the DCP content is in the range of 1.0–1.5 wt.%.

Introduction: Synovial fluid (SF) analysis is one of the most important tests used in approach to arthritis and is necessary for rheumatology fellowship training. It depends on the operator's experience and can be affected by handling, processing, temperature, type of preservative, and time from aspiration to analysis. Therefore, we aimed to reevaluate the SF with positive results for crystals, after at least 10 days for the persistency and visibility of the crystals. Method: For 1 year, we reevaluated crystal positive synovial fluid samples after at least 10 days under light and polarized microscopy. The samples were sent in tubes without any preservative. After the first day of diagnosis of a crystal arthropathy, all the samples were kept in 4 °C refrigerator in a syringe without any preservative and then reevaluated. Results: 14 calcium pyrophosphate (CPP); 12 monosodium urate (MSU), 1 of which was combined CPP and MSU; and 1 post-methylprednisolone (Depomedrol) injection, steroid crystal arthropathy were found and reevaluated. In all reevaluated samples [between 10–24 (median:14 days)], the crystals were detectable again. Conclusion: Our results suggests that SF CPP, MSU and methylprednisolone crystals at 4 °C without preservation could be detectable after 10–24 days (median: 14, 15.5, and 10 days, respectively) under light and polarized microscopy. It seems that the samples evaluated in emergency settings without enough time and those sent from other centers or gathering samples for trainees can be kept to detect crystals at least 10 days for all and till 22 days (for CCP and MSU) after sampling. [ABSTRACT FROM AUTHOR]

Copyright of Precious Metals / Guijinshu is the property of Precious Metals Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We provide a new tableau model from which one can easily deduce the characters of finite-dimensional irreducible polynomial representations of the special orthogonal group S O n (C) . This model originates from the representation theory of the ı quantum group (also known as the quantum symmetric pair coideal subalgebra) of type A I and is equipped with a combinatorial structure, which we call A I -crystal structure. This structure enables us to describe combinatorially the tensor product of an S O n (C) -module and a G L n (C) -module, and the branching from G L n (C) to S O n (C) . [ABSTRACT FROM AUTHOR]

The crystal structure of tetra-n-butylammonium perchlorate has been successfully elucidated using single-crystal X-ray diffraction. The compound crystallizes in the triclinic space group P 1 ¯ with unit cell of dimensions a = 14.2706(7) Å, b = 20.6904(9) Å, c = 39.970(2) Å, α = 89.316(4)°, β = 88.638(4)°, and γ = 87.801(4)°. Although complicated by partial disorder, the structure has remarkable features where columns of some of the perchlorate anions running down [100] lie within what can be regarded as nanotubular entities formed by some of the tetrabutylammonium cations, while the remaining tetrabutylammonium cations lie in parallel columns surrounded by the remaining perchlorate anions, one entity being essentially the inverse of the other. Interactions within the structure have been characterized using Hirshfeld surface analysis and comparisons drawn with other unsolvated salts of the cation. [ABSTRACT FROM AUTHOR]

By borrowing the four gems in the “Treasure Hid in Chinese Poetry” and introducing their main components, functions and chemical principles in a personified way, the readers can understand the preciousness of the four gems and the chemical knowledge contained in the interesting reading. [ABSTRACT FROM AUTHOR]

The absorption and emission cross-section spectra of LiNbO3:Tm3+ crystals were investigated within the wavelength range of 1 65 0-2 000 nm at room temperature. This study delves into the potential for achieving radiation-balanced lasing. Optimal parameters for both the pump and emission wavelengths, denoted as λOP and λOL, respectively, were determined. At these wavelengths, the corresponding optimal values for gain Fgain ≅ 0.8 x 10-22 cm² and radiation-balanced generation efficiency Feff ≅ 0.4 x 10-22 cm² were identified. These findings underscore the feasibility of radiation-balanced lasing in LiNbO3:Tm3+ crystals under the specified conditions. [ABSTRACT FROM AUTHOR]

A 6‐year‐old female spayed Great Dane was evaluated for acute onset cluster seizures. Magnetic resonance imaging (MRI) identified a mass in the olfactory bulbs with a large mucoid component caudal to the primary mass. The mass was removed via transfrontal craniotomy and histopathology revealed a tyrosine crystalline‐rich, fibrous meningioma with a high mitotic index. Repeat MRI at 6 months showed no detectable tumor regrowth. The dog is clinically normal with no seizures at the time of publication 10 months after surgery. This meningioma subtype is rare in humans. This unique meningioma occurred in a dog of younger age and uncommon breed for intracranial meningioma. Biological progression of this tumor subtype is unknown; however, growth rate might be slow despite the high mitotic index. [ABSTRACT FROM AUTHOR]

The hydration product Fe(OH)3 gel phase or Al-containing Fe(OH)3 [abbreviated as (A/F)H3 ] gel phase enables calcium sulfoaluminate cement (CSA) to obtain excellent cementitious properties. The formation of these two gels is closely related to the ratio of Al and Fe in the raw materials. The microstructure and properties of hydration products in CSA are seriously affected by the ratio of Al and Fe, and the effect on the gel cannot be ignored. In order to enable the influence relationship between the ratio of Al and Fe and the gel phase was thoroughly investigated. In this study, (A/F)H3 with different Al/(Fe+Al) ratios was synthesized from its chemical composition by sol-gel method, and its microstructure was characterized to determine the formation process of this phase. X-ray diffraction (XRD), thermogravimetric analysis (TGA), inductively coupled plasma emission spectroscopy (ICP), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscope (TEM) and N2 adsorption-Brunauer Emmett Teller (BET) were utilized to investigate the microstructure of (A/F)H3 with different Al/(Fe+Al) ratios. The results show that Fe in Fe(OH)3 was substituted by Al to form the (A/F)H3 phase of goethite crystal structure at pH=12.5. The gradual increase of Al/(Fe+Al) ratios significantly changed the crystal structure parameters of (A/F)H3 , and the adsorption capacity and desorption temperature of -OH groups were improved. When the ratio was greater than 40% by mol, the crystal structure of (A/F)H3 was transformed, and the crystallinity was significantly reduced. In addition, the substitution of Al resulted in a significant decrease in the aspect ratio of the (A/F)H3 phase particles, the microscopic morphology changed from needle-rod to granular, and a larger specific surface area was obtained. [ABSTRACT FROM AUTHOR]

Radial free harmonic wave propagation is considered for the investigation in cylindrical shells made of orthotropic human bones, transversely isotropic hexagonal crystals and simply isotropic materials under the effect of magnetic field and hydrostatic state of stress. Numerical investigations are performed for the frequency equation through 2D and 3D graphical visuals for the impact of rotation, hydrostatic stress, axial magnetic field, inner and outer radii of the cylindrical shell on the radial phase velocity of the wave. A comparative study has been developed for femoral, tibia, mandibular buccal and lingua bones, Mg, Co, Cd, Zn, beryl and ice hexagonal crystals. [ABSTRACT FROM AUTHOR]

If the SrCl2-Tl+ crystals get irradiated with ionizing radiation at a temperature of 80-150 K, the low-temperature color centers appear in them, having surplus electric charge relative to the lattice as a result of capturing electrons and holes by the impurity-vacancy dipoles. If the crystal is irradiated at temperatures above 150 K, when the anionic vacancies can migrate, the high-temperature color centers emerge, which are electrically neutral relative to the lattice. Hence, the coloration of crystal is more effective at high temperatures. However, if the crystal irradiated at high temperatures is cooled down to 80 K, then discolored and re-irradiated with ionizing radiation, both types of color centers are effectively generated in it. Namely, SrCl2-Tl+ crystals have "radiation memory" and, as a result of such modifications, the effectiveness of crystal coloration at low temperatures increases several times. The parameters of radiation sensitivity of the SrCl2-Tl+ crystals were calculated in a one-dimensional model. The limit concentrations of the color centers as a function of the concentration of the Tl+-impurity in the crystal were defined. The calculation results are in good agreement with the experimental data, which confirms the validity of using such a one-dimensional model for predicting the radiation properties of real crystals and searching for ways to increase the effectiveness of crystal coloration. [ABSTRACT FROM AUTHOR]

In this work, a study on large-diameter GaAs ingot growth is presented. Optimized temperature control technology is developed. Horizontal and vertical temperature application technologies with optimum conditions are investigated. The design result is verified through thermal analysis. In addition, polishing process technology for large-diameter GaAs substrates is developed. Simulation data were used to carry out experiments to determine the optimum temperature conditions. As a result of the defect analysis, the final manufacturing result is found to have excellent thickness variations. This presents the validity of the manufacturing process developed in this work. [ABSTRACT FROM AUTHOR]

In eukaryotic cells, vesicular transport plays a crucial role in the docking and fusion of secretory vesicles with their respective target membranes. This intricate process is dependent on a complex network of multiple molecules. One of the important processes is tethering. The exocyst complex facilitates the tethering of secretory vesicles to the plasma membrane during exocytosis. The Sec6 subunit in yeast interacts with other exocyst subunits and may regulate SNARE assembly, which is crucial for understanding the assembly mechanism of exocyst and its interaction with SNARE. In this study, we designed two truncated forms of HuSec6, HuSec6 121-734 and HuSec6 121-745, based on results of bioinformatics analysis. We expressed and purified the proteins in E. coli, obtaining a protein purity of over 95% and protein crystals. X-ray diffraction results showed a resolution of approximately 9 Å for the crystals, providing a solid foundation for the crystal structure analysis of HuSec6. [ABSTRACT FROM AUTHOR]

Consistent basis sets of triple‐zeta valence quality for the elements La‐Lu were derived for periodic quantum‐chemical solid‐state calculations. They are an extension of the pob‐TZVP‐rev2 [D. Vilela Oliveira, et al., J. Comput. Chem. 2019, 40(27), 2364–2376], [J. Laun and T. Bredow, J. Comput. Chem. 2021, 42(15), 1064–1072], [J. Laun and T. Bredow, J. Comput. Chem. 2022, 43(12), 839–846] basis sets and are based on the fully relativistic effective core potentials of the Stuttgart/Cologne group and on the def2‐TZVP valence basis of the Ahlrichs group. The basis sets are constructed to minimize the basis set superposition error in crystalline systems. The contraction scheme, orbital exponents, and contraction coefficients were optimized in order to ensure robust and stable self‐consistent‐field convergence for a set of compounds and metals. For the applied PW1PW hybrid functional, the average deviations of the calculated lattice constants from experimental references are smaller with pob‐TZV‐rev2 than with standard basis sets available from the CRYSTAL basis set database. After augmentation with single diffuse s‐ and p‐functions, reference plane‐wave band structures of metals can be accurately reproduced. [ABSTRACT FROM AUTHOR]

The terms that Galileo's contemporaries used for lenses (cristallo/i, lente/i, and vetro/i) have often been treated, and even translated, interchangeably. In this article, we argue that Galileo used references to crystals as lenses to embed epistemological and cosmological arguments in the material object of the telescope. Across Galileo's correspondence and letters, the term crystal had many uses and meanings. As a substance, crystal was a form of raw material, but crystal was also a substance that was central to scholastic cosmology and an explanatory device on which scholastics relied to explain first the appearance of the new star of 1604 and then Galileo's new telescopic discoveries. When Galileo began using the word crystals as a synonym for lenses, he endowed the material of his instrument with cosmological arguments. Galileo's choice of language was deliberate and polemical, serving as a joke at the expense of scholastics and as a linguistic marker of social proximity to Galileo and his intellectual agenda, especially among the members of the Academy of the Lincei. Rhetorically and linguistically, Galileo chose to refer to his lenses as crystals both because of the material from which they were made and because in so doing he signaled the epistemological work that the lenses would perform. Ultimately, the crystal lenses in Galileo's telescope and writings shattered the crystalline spheres, replacing explanatory metaphors with a polemical emphasis on the material and empirical realities of objects. [ABSTRACT FROM AUTHOR]

A terbium 2,6-naphthalenedisulfonic acid compound, [Tb(H2O)9]Cl(C10H6O4S4)2 (C10H6O4S42− = 2,6-naphthalenedisulfonate), is prepared and characterized by single-crystal X-ray diffraction. This compound is characterized by an isolated structure with the terbium ion possessing a mono-capped square antiprism coordination geometry. The [Tb(H2O)9]3+ cations and (2,6-naphthalenedisulfonic acid)2− anions are linked by hydrogen-bonding interactions to yield a three-dimensional supramolecular network. The solid state luminescence spectrum reveals that this compound shows the strongest emission band in the red region. The luminescence emission peaks can be ascribed to the characteristic emissions of the 4f electron intrashell transitions 5D4 → 7F5, 5D4 → 7F4 and 5D4 → 7F2 of the Tb3+ ion. The CIE (Commission Internationale de L'Eclairage) chromaticity coordinates are (0.5647, 0.4338). Solid-state UV/Vis diffuse reflectance spectra reveal that compound 1 shows a wide optical band gap of 4.92 eV. A novel terbium 2,6-naphthalenedisulfonic acid compound is prepared and characterized [ABSTRACT FROM AUTHOR]

The structure of four hydroxamic acids (HA) that show antifungal activities in complexes with several metals is revealed by single crystal diffraction. The structures of HA with C2, C6, C10, and C12 hydrocarbon chains are reported. The smallest member of the series, N-hydroxyacetamide (HA2), crystallizes in the centrosymmetric space group P21/c while those with longer chain lengths N-hydroxyhexanamide (HA6), N-hydroxydecanamide (HA10), and N-hydroxydodecanamide (HA12) crystallize in the space group P21, and display remarkable packing. [ABSTRACT FROM AUTHOR]

Enzymatic interesterification (EIE) of beef tallow (BT) blended with soybean oil (SO), peanut oil (PO) and canola oil (CO) in different proportions were analyzed in terms of the fatty acid compositions, thermal properties (melting and crystallization behaviors), rheological properties, hardness, crystal, and microstructure to achieve their sufficient utilization. The content of saturated fatty acids in all interesterified oils (IOs) decreased gradually with the increase of plant oil content in base stock. The higher the proportion of plant oil in the base stock, the lower the enthalpy of IOs. All IOs were in the solid-like state, and the hardness of all IOs met the requirements of traditional plastic oil. All IOs were mainly in α and β′ crystal forms and can be used as basic stock for special oils. [ABSTRACT FROM AUTHOR]

Ceramic ZnO-SnO2-Fe2O3 powders and transparent coatings on glasses prepared using the non-isothermal polymer-salt method demonstrate a strong ability to generate chemically active oxygen species under UV and visible irradiation. Crystal structures and morphologies of these materials were studied using the XRD and the SEM analysis. It was found that there are significant differences in the crystal structure of ceramic powders and thin coatings. The powders consist of randomly oriented oxide nanocrystals of size ~47 nm. The strong orientation of the ZnO nanocrystals due to their interaction with the glass substrate is observed in the coating structure. Experimental data show that thin ceramic coatings are transparent (~90%) in the visible spectral range and the band gap of the ceramic material is 3.44 eV. The band gap value of this multi-component ceramic material is described sufficiently using Verlag's law. Ceramic powders and coatings demonstrate the intensive photogeneration of reactive oxygen species, both in liquid and air. High photocatalytic activity of ZnO-SnO2-Fe2O3 ceramic coatings and powders was observed upon the oxidation of the diazo dye, Chicago Sky Blue. In the presence of transparent photocatalytic coating, the value of the constant rate of the dye photodecomposition was high (k = 0.056 min−1). It was found that, in spite of their short life time, photogenerated reactive oxygen species demonstrate the ability to decompose dye molecules located up to a distance of 0.5 mm from the surface of ceramic coating. Obtained experimental results suggest that the prepared ceramic materials are promising for different practical applications of the photocatalytic materials. [ABSTRACT FROM AUTHOR]

By solution growth process, metal organic single crystalline material bis(2,6-diaminopyridin-1-ium) hexaaquacobalt(II)disulfatedihydrate (ACS) was grown efficaciously. Crystal Bis(2,6-diaminopuridin-1-ium) hexaaquacobalt(II)disulfatedehydrate synthesized and theoretically studied utilizing Density Functional Theory (DFT) through B3LYP/6-31G(d,p) basis set for all scheming. Electric absorption, gaseous phase absorption and UV–vis spectroscopy are characterized for ACS. Theoretical studies show ACS has electrical belongings and reduced bandgap HOMO–LUMO energies from electrochemical and optical testing are suitable for use as donor materials. First-order NLO response, molecular electrostatic potential, global chemical reactivity descriptors, were investigated. ACS single crystal was subjected to structural, crystallinity, optical, mechanical, and Z–scan. [ABSTRACT FROM AUTHOR]

The orientational dependence of Poisson's ratio ν in tetragonal single crystalline γ-TiAl was calculated based on previously measured single crystal elastic constants. Depending on the orientation of the applied stress, ν can be quite isotropic or highly anisotropic when the transverse direction varies. For example, when the stress axis is along the [001] direction, the resulting Poisson's ratio is a constant independent of the transverse direction; when the stress tensile axis is perpendicular to the 1 ¯ 01 crystallographic plane, ν is highly anisotropic, varying from a slightly negative value to more than 0.40. Orientational dependence of Poisson's ratio ν in γ-TiAl single crystal for a [110] tensile direction at T = 298 K . θ is the angle between the [001] crystal axis and the transverse direction. [ABSTRACT FROM AUTHOR]

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The optical properties of nominally pure LiNbO3stoich, near-stoichiometric LiNbO3stoich (6,0 wt% K2O), LiNbO3cong and LiNbO3:B (0,55 and 0,83 mol% B2O3 in the charge) crystals in the visible region of the spectrum (λ = 380-700 nm) were studied by photoluminescence. LiNbO3:B crystals were grown by Czochralski using the technology of a direct solid-phase doping of the congruent charge by boron oxide (B2O3). The photoluminescence intensity increases in the series of crystals: LiNbO3stoich, LiNbO3stoich (6,0 wt% K2O), and LiNbO3cong. The photoluminescence intensity is determined by the concentration of deep electron traps (NbLi – «niobium antisite») and the stoichiometry of these crystals. The photoluminescence intensity of LiNbO3:B (0,55 and 0,83 mol% B2O3 in the charge) crystals is close to the photoluminescence intensity of LiNbO3stoich crystal. This can be explained by the fact that the composition and structure of LiNbO3:B (0,55 and 0,83 mol% B2O3 in the charge) crystals approach the composition and structure of the stoichiometric crystal.

Specific features of the defect structure of nominally pure LiNbO3:B crystals were studied by the X-ray diffraction analysis. Nominally pure LiNbO3:B crystals were grown by Czochralski using the technology of the direct solid-phase doping of the congruent charge by orthoboric acid (H3BO3). The bonds lengths of Me-O in MeO6 clusters (Me-Li, Nb) determine the ferroelectric and nonlinear optical properties of the lithium niobate crystal. The values of these bonds in LiNbO3:B crystals differ significantly from the bonds lengths of the nominally pure congruent crystal LiNbO3cong. The differences in the bonds lengths are caused by a change in the properties of the boron-containing melt, technological parameters of the growth of LiNbO3:B crystals, and the localization of a trace amounts of boron in tetrahedral voids of the lithium niobate crystal structure. The results of the study of LiNbO3:B crystals were compared with those for nominally pure LiNbO3cong crystals and near-stoichiometric LiNbO3stoich (5,5 wt% K2O) ones.

Objective. The objective of the study is to increase the reliability of the contact of the semiconductor transistor crystal to the body and the reproducibility of the technological process.Method. A method for obtaining multilayer metallization of the reverse side of the crystal has been developed and the most optimal technological modes of its formation have been selected. The parameters of the reliability of the connection of the crystal to the body of the transistor were checked.Results. Layer-by-layer metallization has been obtained, which provides a strong contact to the collector region of the transistor and a reliable fit of the crystal to the base of the case.The control of technological operations showed 100% distribution of solder over the surface of the crystal, the absence of pores in the solder, the improvement in the output characteristics of the device and the increase in the percentage of output usable transistors.Conclusion. An analysis of the experimental results showed that in order to create a reliable contact and remove heat from the collector junction of power semiconductor transistors on the reverse side of the plates, it is necessary to form a metallization in one technological cycle, consisting of four layers of metals (Cr-Ni-Sn-Ag). The technical result of the research is to improve the quality of fit by obtaining a uniform distribution of the layer of Cr-Ni-Sn-Ag metals in a single technological cycle.

Abstract Quartz crystals are found in nature. It is believed that these crystals are eco‐friendly and known for healing, decoration, and gem therapy. However, there is no scientific evidence of such effects, except it is a piezoelectric material. The piezocatalytic effect is viewed as having significant potential for tackling environmental challenges such as water cleaning. The piezocatalytic performance of Quartz crystals was examined and reported for a few dyes degradation. The purity of these crystals was confirmed via X‐ray diffraction, Raman spectroscopy, and X‐ray photoelectron spectroscopy analysis before experimentation. Degradation of organic dyes methylene blue, methylene violet, and Rhodamine b (RB) dyes from aqueous solutions was observed using these crystals. Naturally occurred Quartz was exposed to ultrasonic vibrations for dyes and its piezocatalytic property was studied. Furthermore, using the germination index of Cicer arientium the treated water was utilized as a growth parameter. The signature of dye degradation indicates their eco‐friendly behavior. It can be assumed that these crystals can actively participate to clean organic pollutants under the application of mechanical vibrations.

This paper is dealing with the dissolution mechanism of crystalline sulindac into amorphous Polyvinylpyrrolidone (PVP) upon heating and annealing at high temperatures. Special attention is paid on the diffusion mechanism of drug molecules in the polymer which leads to a homogeneous amorphous solid dispersion of the two components. The results show that isothermal dissolution proceeds through the growth of polymer zones saturated by the drug, and not by a progressive increase in the uniform drug concentration in the whole polymer matrix. The investigations also show the exceptional ability of temperature Modulated Differential Scanning Calorimetry (MDSC) to identify the equilibrium and out of equilibrium stages of dissolution corresponding to the trajectory of the mixture into its state diagram. [ABSTRACT FROM AUTHOR]

As an engineering material, polyether ether ketone (PEEK) has been widely used in many fields. It is important to study its thermal oxidative aging law for its material service optimization. The changes of chemical structure and relative properties of PEEK sheets after thermal oxygen aging at 280°C for different times were measured by universal tensile machine, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and resistance meter. The results showed that the elongation at break of the aged samples decreased with the extension of thermal aging time, while the tensile strength continuously increased within 336 h of thermal aging and then decreased gradually. Moreover, the crystallization temperature, melting enthalpy, and crystallinity of the samples decreased with the increase of thermal aging time. The crystallinity decreased to 2.3% after 2852 h aging and the initial decomposition temperature and the maximum decomposition temperature of PEEK gradually decreased from 554.3 to 523.5°C and 572.9 to 558.2°C, respectively. The increase of tan δ was more significant in the low frequency band (10−2–101) Hz. With the increase of aging time, the zeta potential of PEEK surface constantly moved to the negative direction and the volume resistivity and the dielectric strength similarly increased first and then decreased. [ABSTRACT FROM AUTHOR]

[Display omitted] Colloidal particles can be used to generate water-in-oil (W/O) emulsions resistant against coalescence. Demulsification is possible with addition of low molecular weight surfactants to the emulsion continuous oil phase. Whether surfactants demulsify particle-stabilized W/O emulsions depends on their ability to modify the wettability of interfacially-bound particles. Crystals of glycerol monostearate (GMS) were prepared followed by water addition to generate GMS-stabilized W/O emulsions. The surfactants sorbitan monooleate (SMO), sorbitan monolaurate (SML), citric acid esters of monoglycerides (CITREM), sorbitan trioleate (STO), propylene glycol monolaurate (PgML), and polyglycerol polyricinoleate (PGPR) were added to the emulsion oil phase. Emulsion microstructure was characterized by light microscopy and cryo-scanning electron microscopy. Surfactant activity and crystal wetting were characterized by interfacial tension and three-phase contact angle measurements. Salt release from within the emulsions was used to assess demulsifier efficacy. Emulsions stabilized by platelet-like GMS crystals were generated. Of the six surfactants, SMO, SML, and CITREM were effective demulsifiers whereas STO, PgML, and PGPR were ineffective. The former three sufficiently modified the wettability of GMS crystals on the droplet surface, as they adsorbed to both the oil–water interface and GMS crystal surface. Emulsion destabilization was associated with faster NaCl release from the emulsion internal phase. [ABSTRACT FROM AUTHOR]

It has been found that the gas-phase diffusion of gallium and phosphorus atoms into silicon provides not only the compensation but also partial interaction of the elements with each other. Analysis under a scanning electron microscope has shown that, after diffusion and surface treatment, gallium and phosphorus atoms are present on the silicon surface in similar concentrations. Studies of the concentration distribution of charge carriers over depth have shown that, upon codiffusion, the solubility of gallium increases by an order of magnitude, while the charge carrier mobility decreases by a factor of three to four. Based on the obtained data, the concentration (~1019 cm–3) and energy of formation (~0.62 eV) of neutral complexes [Ga–P+] have been calculated. The results can be attributed to the electrostatic interaction of gallium and phosphorus ions during diffusion, which leads to a change in the concentration distribution of the impurities and the formation of quasi-neutral complexes of the [Ga–P+] type in the silicon lattice. [ABSTRACT FROM AUTHOR]

The effects of the resonant scattering of fast relativistic leptons directed at small angles relative to a selected crystallographic plane are considered. Simultaneously, the processes of radiation and the generation of excitations in crystals by a collimated beam of channeled leptons entering a single crystal at small angles (both greater and less than the Lindhard angle ) are considered from a unified point of view. The processes of the Raman scattering of a monochromatic electromagnetic wave by channeled relativistic leptons (electrons, positrons), which experience the effect of resonant scattering at a small angle of entry relative to a selected crystallographic plane are theoretically studied, as well as the processes of Raman scattering by the relaxing deeply nonequilibrium electron-phonon system of the semiconductor, excited by a relativistic beam of charged leptons of subnanosecond duration directed at a small angle to the crystallographic plane. [ABSTRACT FROM AUTHOR]

Since its introduction in the early 1970s, high pressure crystallography (HPX) has shown great potential for the investigation of different types of matter. Using diamond anvil cells, HPX is an emerging technique that has been rapidly implemented, making it available to biologists, and there is immense potential for utilizing this technique in biological systems in the future. At the molecular level, high-pressure crystallographic investigation provides information on structural characteristics that not only determine the native conformation of a protein but also the conformations with higher free-energy, thus revealing function-related structural changes and properties that can be modified as a result of pressurization. The increase in the number of crystal structures of different macromolecules determined under high pressure over the last five decades can be ascribed mainly to two factors: the emergence of high-pressure cells with very large, open angles, and the advent of third generation synchrotron sources. The use of high pressure crystallography as a research tool has been shown to contribute to the advancements in the basic fields of biochemistry (protein misfolding and aggregation), biophysics (protein stability), and biotechnology (food processing). Presently, with a growing interest in biomedicine and nanotechnology, this nonstandard method appears to be a valid instrument for probing more challenging and complex systems. In this review, we present the method, highlight a selection of recent applications, and describe challenges for high pressure macromolecular crystallography (HPMX). [ABSTRACT FROM AUTHOR]

Various classification approaches have been developed for geometric form of crystals. One method involves the generation of three-dimensional (3D) models of crystals, mainly through graphical representations. However, traditional graphical representations mainly depend on symmetrical operations of crystal planes and the application of polar stereographic projections. There is still very few geometric analysis or mathematical expression for the rectangular coordinate system, implying the limited 3D visualization of crystal forms. In this paper, we present a newly geometric analysis that allows 3D visualization analysis of crystal forms and further identifies geometric relations between crystal forms. In detail, crystal models are divided in a 3D rectangular coordinate system within 47 types of geometric form into the tetrahedron, polygon (polyhedron), and cube classes. What's more, we determine the vertex space coordinates of the 47 types of crystal form through geometric analysis and coordinate calculation of the crystal forms. Last but not least, in order to obtain 3D models of every geometric form under the automorphism of crystals, it is the convex envelope geometric polyhedron algorithm created to calculate the edges and triangular faces by WebGL technology, which makes it possible to accomplish an online interactive 3D crystallographic study system in a web-browser. [ABSTRACT FROM AUTHOR]