Types Of Crystals Research Articles

Long-term mechanical performance of fly ash-incorporated reactive magnesia cements

In this research, after producing reactive magnesia directly from calcination of magnesite, reactive magnesia specimens with fly ash were prepared and cured in two different environments to investigate their long-term mechanical performance by carbonation. To investigate the effect on their microstructures of carbonation, the XRD profiles of the samples were also obtained and investigated. It is found that the strength of reactive magnesia samples is highly affected by the addition rate of reactive magnesia and the curing regime. In spite of the presence of the nesquehonite (MgCO3.3H2O) in the reactive magnesia cements having no portland cement, any type of magnesium carbonate crystal was not found for the cements with portland cement in carbon dioxide curing. The strength increase in reactive magnesia cements can be due to the incorporation of Mg2+ ions to the calcite crystals.

Enhancing the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 by surface modification with homemade high-purity hexagonal phase tungsten oxide nanoparticles

Nickel-rich layered oxides with high energy density and acceptable cost are considered as one of the most ideal cathode materials for power batteries. However, its large-scale production and application still face the challenge in terms of rapid capacity fading and poor structural stability, which has prompted research into surface coating materials/technologies within both academic and industrial fields. In this work, A feasible and environmental friendly fabrication method of high-purity hexagonal phase tungsten oxide (h-WO3) nanoparticles as surface modification of LiNi0.8Co0.1Mn0.1O2(NCM) is proposed.The results indicate that NCM modified with h-WO3 has lower Li+/Ni2+ mixing rate, superior rate performance, and better cycling stability than the pristine NCM. Although tungsten oxide is widely used as surface modification due to its excellent physical and chemical properties, but its crystal type has not been considered, and there is little research on the theoretical explanation of h-WO3 modification.This work reveals the working mechanism of h-WO3 from the perspective of interface and crystal type, which can provide meaningful reference for obtaining nickel-rich layered oxides with excellent electrochemical properties.

Dynamic characteristics and microscopic mechanism of graphene oxide modified coastal soft soil under small strain

Graphene oxide (GO) has been shown to improve the static mechanical properties of cement soils. However, the dynamic mechanical properties of GO-modified cement soils are rarely investigated. Therefore, in this study, the effects of different confining pressures, GO contents, and curing ages on the small-strain dynamic shear modulus (G) and damping ratio (D) of GO-modified coastal cement soil (GOCS) are investigated via resonant column tests. The results show that the G of GOCS increases with the confining pressure, GO content, and curing age, whereas D decreases. Moreover, the GOCS indicate the highest stiffness improvement when 0.05 % GO is used as a modifier. The variation patterns of the maximum dynamic shear modulus and maximum damping ratio with the increase in the confining pressure, GO content, and curing age of the GOCS are consistent with the measured results. Microstructural analysis shows that the incorporation of GO can promote the early cement hydration of GOCS and increase its internal calcium-silicate-hydrate gel as well as its crystal types and numbers. The filling and bridging effects of GO not only enhance the stiffness of GOCS, thus increasing its G value, but also effectively reduce the energy consumption of the vibration wave in the sample, thus reducing its D value. The results of this study can provide important references and guidance for the design and construction of coastal soft-soil roadbed projects.

Strengthened ozone adsorption through positive electric field-induced charge migration on various TiO2 crystal surfaces: A mechanistic and theoretical study

This study investigates the enhancement of ozone adsorption on diverse TiO2 crystal interfaces through an innovative electrochemical modulation approach. The research focuses on the effects of applied electric field strength and reaction sites on ozone interfacial adsorption energies for Ti/Anatase TiO2 (0 0 1) and Ti/Rutile TiO2 (1 1 0) interfaces. The findings reveal that positive electric fields significantly enhance ozone adsorption on both interfaces, with adsorption energies increasing by up to 18% for Ti/Anatase TiO2 (0 0 1) and 15% for Ti/Rutile TiO2 (1 1 0). Notably, double water molecule sites (≡(H2O)2) play a crucial role in this enhancement process. The study demonstrates that the applied electric field alters the charge distribution at the TiO2 catalytic interface, thereby increasing interfacial charge density and promoting charge migration to ozone. Furthermore, this process leads to enhanced overlap and hybridization between ≡(H2O)2 sites and the s and p orbitals of ozone molecules, resulting in the formation of chemical bonds with lower Fermi levels. These comprehensive results demonstrate the broad applicability of the electrochemical interfacial ozone adsorption enhancement method across different crystal types and surfaces. Consequently, this study provides essential data to support the advancement of greener and more energy-efficient heterogeneous catalytic ozonation processes, potentially contributing to significant improvements in ozone-based water treatment technologies.

Seasonal Variances in General Urine Examination Findings among Al-Yarmouk Teaching Hospital Patients

Background: Urinalysis is a common test done for several reasons; for instance, in UTI looking for, hematuria or pseudo-hematuria, pyuria, crystalluria and also looking for different microorganisms (etc...), many laboratories perform either a regular test light microscopy, or examine varying dilutions of urine sediment and fields of view with or without the use of stains or polarization, while other laboratories used analysis of urine using automated system. As being a human; the biological sex(female or male) and broadly influences diverse immune phenotypes, including immune responses to diseases at mucosal surfaces, all contribute to how an organism will respond to diseases of the urinary tract, on the other hand, a close relationship between four seasons and the incidence of UTI has been detected in various areas of the world, where the seasons alternate in a year, and the temperature fluctuates widely among these seasons. Methods: present study was conducted on midstream sample was collected for acquiring accurate results from (68899) individuals (40800 females and 28099 males), these subjects were clinically suspected to have UTI, who were referred to the Department of Teaching Laboratories in AL-Yarmouk Teaching Hospital at Baghdad / Iraq, between January 2020 and December 2023, which examined by; Urilyzer 500 PRO (Analyticon) with Urine strips (dipstick) and Optical Microscope BA 210 (Motic). Results: A total of 68899 urine specimens were tested, of which 28099 male (40.8%) and 40800 female (59.2%) with the highest percentage of urinalysis in 2022 (33.2%), furthermore, the higher percentage of urinalysis parameters was scored in 2021 as follows; pus cells 9012 (49.3%), red blood corpuscles 5284 (48.9%) and crystalluria 3956 (44.2%) with the most common type of crystal was amorphous urate 5032 (56.2%), while highest percentages of microorganisms 1050 (40.3%) in year 2022 , and Bacteria was exhibited the highest percentages 2036 (78.1%). Current study recorded significantly differences between males and females in all urine parameters which was higher percentage in female than male and in the Seasons of (Summer and Autumn) , during the four years of this study. Conclusion: This study registered more accurate diagnostic results of UTI according to the urinary parameters in the microscopic routine urinalysis(centrifugation at 300xg at 5 min) when compared to machines (Urilyzer 500 PRO test/Urine strips) which frequently miss that , in addition, hot season in Iraq could affect to increase the seasonally variable incidence of UTI , as well, increased percentages and frequency of urinary parameters which observed in 2021-2022 out of four study years may indicates, high likelihood side effects of Covid-19 pandemic disease in study persons involved.

Organic Crystals and Optical Functions in Biology: Knowns and Unknowns.

Organic crystals are widely used by animals to manipulate light for producing structural colors and for improving vision. To date only seven crystal types are known to be used, and among them β-guanine crystals are by far the most widespread. The fact that almost all these crystals have unusually high refractive indices (RIs) is consistent with their light manipulation function. Here, the physical, structural, and optical principles of how light interacts with the polarizable free-electron-rich environment of these quasiaromatic molecules are addressed. How the organization of these molecules into crystalline arrays introduces optical anisotropy and finally how organisms control crystal morphology and superstructural organization to optimize functions in light reflection and scattering are also discussed. Many open questions remain in this fascinating field, some of which arise out of this in-depth analysis of the interaction of light with crystal arrays. More types of organic crystals will probably be discovered, as well as other organisms that use these crystals to manipulate light. The insights gained from biological systems can also be harnessed for improving synthetic light-manipulating materials.

Effect of sticky rice on the strength and permeability of bio-cemented sand

Microbially induced carbonate precipitation (MICP) is an eco-friendly soil improvement technique. However, this method still has some drawbacks, such as low conversion efficiency of CaCO3 crystallization, insufficient strength for certain applications, and requiring multiple treatments. Previous studies have reported that sticky rice can regulate CaCO3 crystals (i.e., chemical CaCO3) in the sticky rice-lime mortar, showing potential for improving the bio-cementation. Therefore, this study explored the possibility of using sticky rice to enhance the biocementation effect. Tests were carried out to assess the strength and permeability of bio-cemented sand with the inclusion of sticky rice. The results indicated that sticky rice may regulate the type and size of bio-CaCO3 crystals, and the use of an appropriate amount of sticky rice as additive could increase the strength of sand columns by regulating CaCO3 crystallization. Polyhedral calcites may be more favourable for the increasing strength than some vaterites with a hollow spherical structure. The combination of MICP and sticky rice can significantly decrease the coefficient of permeability to a value that was much lower than that by using sticky rice and MICP alone. Bio-CaCO3 immobilized the sticky rice on one end on sand particles, and the reticulated structure of sticky rice divided large pores into small pores, which may be the important cause of the decrease in permeability coefficient. Finally, this study proposed that the MICP with the sticky rice as an additive may enhance the MICP effect and prevent the surface erosion of coarse-grained sand slopes.

Enhancing the luminescent properties of strontium phosphate glass via controlled crystallization and rare earth dopants

The study focused on investigating the photoluminescence behavior of pure strontium phosphate glasses with a composition of 62.5% P2O5 and 37.5% SrO. Then it was extended to investigate the effects of adding rare earth elements (Pr3+, Sm3+, Eu3+, Dy3+) and the crystallization process on improving luminescent properties of the parent glass. Various spectroscopic measurements, including XRD, SEM & EDAX, and FTIR, were conducted to examine the relationship between structural changes and their impact on luminescent performance. The optical measurements showed a characteristic enhancement resulting from the addition of RE3+-dopants and the crystallization process. The crystallization of glasses yielded a single phase from Sr(PO3)2 with an extended emission peak at 671 nm and heightened intensity compared to the glassy sample. The development of efficient and stable luminescent glasses via crystallization and dopant type can lead to advancements in applications such as glowing devices, optical detectors, and photonics innovations.

SYNTHESIS OF PRECIPITATED CALCIUM CARBONATE IN THE FORM OF CALCITE CRYSTALS AS A VALORIZATION OF LIME CARBIDE SLAG WASTE

The presence of high level of calcium oxide (CaO) has been detected in lime carbide (LC) slag waste generated form the acetylene gas industry. There is untapped potential for the valorization of LC-slag waste, where the calcium oxide content can be converted into Precipitated Calcium Carbonate (PCC/CaCO3) which is valuable and can contribute to carbon dioxide sequestration. Calcium carbonate has unique advantages as a carrier, but some critical problems need to be addressed, such as low productivity, disordered structure, and weak adsorption ability. In this study, the desired type of crystal is calcite which has the most stable characteristics from the other types of crystals. Micro-bubble reactor is used as a method of dispersing CO2 in converting CaO to PCC/CaCO3. This method has the advantage of being able to maintain CO2 gas bubbles longer in solution so that the reaction time that occurs can also be optimize. The LC-Slag valorization process was carried out by varying the LC-slag concentration between 3-7% w/w and the reaction time between 15 - 35 minutes. The dispersion of CO2 gas is fixed at a flow rate of 2.5 L/m. From the yield, it can be seen that the longer the reaction time, the yield of PCC/CaCO3 produced is also greater. At 35 minute reaction time and concentration LC-Slag Waste varied 3, 5, and 7% w/w, the produced yields were 89.44, 95.00, and 93.76%, respectively. This is evidenced by the results of SEM and XRD analysis. In the future, this treatment method is expected to provide more insight and guidance for the valorization of LC-slag waste and CO2 mineralization in the acetylene gas industry.

Chemical-free fabrication of silk fibroin microspheres with silk I structure

Silk fibroin (SF) microspheres show bright prospects for biomedical applications, such as microcarriers, drug delivery, tumor embolization agents, and microscaffolds. However, the chemistry-independent preparation of SF microspheres, which is critical to biomedical applications, has been challenging. In this study, the SF microspheres with silk I crystal type were generated by using electrostatic spraying and freezing-induced assembly. The SF solution was sprayed into liquid nitrogen to form frozen microspheres with tunable size. Annealing can crystallize frozen SF to form silk I crystal type, providing a green approach to harvest water-insoluble microspheres. The SF microspheres can retain a monolithic shape in water for up to 30 days, while having a 77 % degradation ratio in PBS in 14 days, showing high stability in water and rapid degradation under physiological conditions. The biomedical application prospects of the silk I microspheres were demonstrated by cell culture and small molecule drugs (doxorubicin). The microspheres can support the growth and expansion of mammalian cells, and provide a sustainable release for DOX with 10 days. This strategy offers a green approach that avoids the use of organic solvents and cross-linkers for designing SF microsphere biomaterials.

Effect of Sourdough-Yeast Co-Fermentation on Physicochemical Properties of Corn Fagao Batter.

Fagao is one of China's traditional gluten-free staple foods made with rice or corn flour. Corn Fagao prepared by co-fermentation with sourdough and yeast exhibits better quality and less staling compared to traditional yeast-fermented Fagao. The physicochemical properties of corn Fagao batter during sourdough-yeast co-fermentation were investigated. The results showed that compared with yeast fermentation, the gas production and viscosity of the batter increased with co-fermentation. The co-fermented batter showed a higher hydrolysis of starch and less amylose content. The integrity of starch granules in the co-fermented batter was damaged more seriously, and the crystallinity and short-range ordered structure were less than in the yeast-fermented batter, even though the crystal structure type of starch did not obviously change. The peak viscosity, minimum viscosity, final viscosity, decay value, and recovery value of the corn batter were reduced by co-fermentation, which improved the thermal stability of the batter and slowed down the aging. Co-fermentation also resulted in a more pronounced reduction in protein subunit content than yeast fermentation. The changes in the physicochemical properties of the corn Fagao batter help explain the improvement in quality of corn Fagao made from the co-fermentation method and may provide theoretical references for co-fermentation with sourdough and yeast to other gluten-free foods.

TiO2-Supported Catalysts in Low-Temperature Selective Reduction of NOx with NH3: A Review of Recent Progress

Selective catalytic reduction (SCR) stands out as a pivotal method for curbing NOx emissions from flue gas. The support, crucially, for SCR efficacy, loads and interacts with the active components within the catalyst. The catalysts could be amplified by the denitration performance of the catalyst by enhancements in support pore structure, acidity, and mechanical robustness. These improvements ensure efficient interaction between the support and active materials, thereby optimizing the structure and property of the catalysts. TiO2 is the most commonly used support of the NH3-SCR catalyst. The catalyst with TiO2 support has poor thermal stability and a narrow temperature range, which can be improved. This paper reviews the research progress on the effects of various aspects of TiO2 support on the NH3-SCR catalyst’s performance, focusing on the TiO2 crystal type, TiO2 crystal surface, different TiO2 structures, TiO2 support preparation methods, and the effects of TiO2-X composite support on the NH3-SCR catalyst’s performance. The reaction mechanism, denitrification performance, and anti-SO2/H2O poisoning performance and mechanism of TiO2 support with different characteristics were described. At the same time, the development trend of the NH3-SCR catalyst using TiO2 as the support is prospected. It is hoped that this work can provide optimization ideas for SCR catalyst research.

Enhanced magnetic refrigeration capacities of Er6FeSb2 by manganese substitution

Er6FeSb2 is a potential magnetic refrigeration material that can work at the liquid hydrogen temperature range. This work enhances the magnetic refrigeration performance of Er6Fe1-xMnxSb2 by Mn substitution. Mn doping increases the cell volume while maintaining the compound’s crystal structure type. It also results in an increase in the charge density distribution between Er1 and Fe/Mn. As the Mn content increases, the ferromagnetic exchange is enhanced, and the TC continuously increases. The Mn doping induces spin reorientation at low temperature, transforming compounds from traditional magnetocaloric effects to table-like magnetocaloric effects, greatly enlarge the cooling temperature range. When the content of Mn increases from x = 0 to x = 0.3, the δTFWHM increases from 26 K to 62 K, the −(ΔSM)max decreases from 12.1 J/(kg·K) to 5.9 J/(kg·K), and the RCP first increases and then decreases, reaching the maximum value of 435.0 J/kg at x = 0.2. This study opens a new path for the search of magnetic refrigeration material with large cooling temperature range.

Emerging chiral two-dimensional materials.

Research into 2D materials has been growing with impressive speed since the discovery of graphene. Such layered materials with ultrathin morphologies and extreme aspect ratios currently display a vast range of properties; however, until recently a conspicuously missing property of 2D materials was global chirality. The situation has changed over the past few years with the implementation of several distinct types of ultrathin chiral 2D crystals. Here we offer a forward-looking perspective on this field to comprehend the fundamentals of global chirality in two dimensions and develop new directions. We specifically discuss the experimental achievements of the emerging chiral 2D materials with a focus on their design strategy, synthesis, structural characterization, fundamental physical properties and possible applications. We will highlight how the molecular-scale local chirality could be significantly transmitted and amplified throughout ultrathin single-crystalline 2D structures, resulting in distinctive global chirality that brings more sophisticated functions.

Early age accelerated carbonation of cementitious materials surface in low CO2 concentration condition

Accelerated carbonation curing contributes to the carbon sequestration effect of cementitious materials and enhances surface density. However, in large-scale applications, traditional high CO2 concentration conditions (>5 % CO2) are constrained by economic costs. This study traces the early-stage accelerated carbonation process of cement mortar under low CO2 concentration (3 % CO2) condition from the perspectives of the evolution of CaCO3 crystal types, phase transformations, and microstructural changes, and compares the results with those under the 20 % CO2 condition. The results show that the carbonation depth of mortar specimens cured under the 3 % CO2 condition is shallower, but the cumulative concentration of CaCO3 within the surface 3 mm is not significantly lower than that under the 20 % CO2 condition; The carbonation zone generates more low-crystalline forms of CaCO3; The accelerated carbonation process does not affect the formation of CH and ettringite. Microscopic results indicate that under the 3 % CO2 condition, the synergistic effects of hydration and carbonation are better, and appropriately extending the curing time helps to refine the pore structure of the carbonation zone and improve the density of the substrate surface.

Covalent-Organic Frameworks for Selective and Sensitive Detection of Antibiotics from Water.

As the consumption of antibiotics rises, they have generated some negative impacts on organisms and the environment because they are often unable to be effectively degraded, and seeking effective detection methods is currently a challenge. Covalent-organic frameworks (COFs) are new types of crystalline porous crystals created based on the strong covalent interactions between blocked monomers, and COFs demonstrate great potential in the detection of antibiotics from aqueous solutions because of their large surface area, adjustable porosity, recyclability, and predictable structure. This review aims to present state-of-the-art insights into COFs (properties, classification, synthesis methods, and functionalization). The key mechanisms for the detection of antibiotics and the application performance of COFs in the detection of antibiotics from water are also discussed, followed by the challenges and opportunities for COFs in future research.

Resolving localized geometrically necessary dislocation densities in Al-Mg polycrystal via in situ EBSD

The distribution of geometrically necessary dislocation (GND) densities is critical to understanding the heterogeneous plastic deformation at intragranular scales in polycrystals. In this work, we performed an in situ electron backscatter diffraction (EBSD) measurement during the tensile test on a polycrystalline Al-Mg alloy. The EBSD patterns were processed through the integrated digital image correlation algorithm to enhance angular resolution. Based on the Nye dislocation density tensor, GND densities of 18 dislocation types in fcc crystals were resolved and mapped at macroscopic strains ranging from 5% to 16%. The evolution of GND distribution showed that GNDs were generated near grain boundaries at small strains and later localized at grain interiors along subgrain boundaries and slip bands at large strains. The inhomogeneous increase in GND densities of different dislocation types, representing dislocation substructures, along the subgrain boundaries was disclosed. Meanwhile, high GND densities were observed along the slip bands when a double noncoplanar slip system was activated inside the grains. The obstructed movement of dislocations by Lomer junctions explained the GND storage in different {111} slip planes. The existence of Lomer junctions was proven by Burgers circuit analysis with high-resolution transmission electron microscopy, which explained the increase in [101] screw dislocation density according to the dislocation reaction.

Ozone modification of waxy rice starch nanocrystals: Effects on the multi-scale structural and surface properties

The rich active hydroxyl groups on starch nanocrystals (SNC) surface limits its dispersion and stability in the aqueous phase. To address this issue, ozone modification for 0 (SNC), 0.5 (SNC-1), 1 (SNC-2), 1.5 (SNC-3), and 2 h (SNC-4) as compared to conventionally chemical methods was applied to functionally modify the SNC. The impact of ozone treatment on the structural and surface characteristics of waxy rice starch nanocrystals. The findings revealed that longer ozone treatment durations favored the formation of carbonyl groups in starch molecules. Initially, ozone oxidized the hydroxyl group of the macromolecule. Once the carbonyl groups formed, the cross-linking reaction occurred among starch nanocrystals through condensation reactions, leading to the increasing molecular orderliness. X-ray photoelectron spectroscopy, X-ray diffraction and Small-angle X-ray scattering analyses of SNC-2 supported this finding with a reduced O/C ratio, and implied that surface oxidation did not alter the crystal type but rather enhanced molecular hydration in an aqueous system, leading to increased interfacial thickness and fractal dimension. Additionally, ozone oxidation improved surface properties such as charge and hydrophobicity. Oxidized SNC also exhibited altered gelatinization properties due to surface degradation. This study offers a promising strategy for enhancing SNC surface properties, crucial for food science applications.

Novel nanostructured transparent Na2O–Al2O3–SiO2 carnegieite-based glass ceramics with high crystallinity

Developing next-generation cover glasses with high crystallinity and transmittance, such as transparent nanocrystalline Na2O–Al2O3–SiO2 (NAS) glass, has proved highly challenging. Herein, we propose a novel nanostructured transparent NAS glass–ceramic with high crystallinity (65 %) and transmittance (91 %) owing to the involved separation of crystallization peaks and the diffusion barrier properties of ZrO2. Compared with untreated glass, this glass-ceramic shows a considerable increase in hardness (from 5.18 to 7.15 GPa, i.e. >38 %). With the increased crystallinity, no substantial reduction in transmission is detected and the crystal type and size can be effectively controlled by the limitation of ZrO2. Hence, the findings project a novel method for creating high crystallinity and transmittance, providing new directions for transparent NAS glass–ceramic.

Tailoring Optical Properties of Rare‐Earth Doped Oxyfluoride Glass‐Ceramics by Tuning Crystal Structure

AbstractIt is known that oxyfluoride glasses can be used as the host for fluoride crystals that feature promising optical properties. This work demonstrates that the optical properties of the Er3+‐Yb3+ co‐doped oxyfluoride precursor glass‐ceramic (PGC) can be tailored by changing crystal structure through chemical variation (LaF3/BaF2 = 0, 1/3; YF3/LaF3 ratios = 0, 2/7, 4/7, 6/7, 1) and heat treatment. The strong correlations between the crystallization behavior, microstructure, and optical properties are revealed. It is found that the precipitated crystals such as BaF2, Ba2LaF7, Ba2‐xLa1‐xYxF7‐2x (0 < x <1), and BaYF5 are uniformly distributed in the glass matrices of PGC. Upon heat‐treatment, the crystallinity of PGC increases, whereas the crystal type remains unchanged. Both the up‐conversion luminescence and optical transmittance of the samples strongly depend on the substitution of one type of fluoride for another. Moreover, by taking advantage of the effect of crystal structure on the cross‐relaxation propensity of Er3+ ions, it is feasible to tune the up‐conversion luminescence color from green to light yellow. It is unveiled that the enhanced cross‐relaxation arises from lattice shrinkage. This work provides guidance for optimizing the optical properties of rare‐earth‐doped oxyfluoride glass ceramics.