Crystallographic Nature Research Articles

Cullen corylifolium (L.) Medik. Seed Extract, an Excellent System For Fabrication of Silver Nanoparticles and Their Multipotency Validation Against Different Mosquito Vectors and Human Cervical Cancer Cell Line

Development of therapeutic drugs for mosquito control and cancer is the need of the hour. This study highlights the fabrication of silver nanoparticles by incubating 45 ml of AgNO3 (0.5 mM) solution with 5 ml of Cullen corylifolium aqueous green seed extract at 60 ± 2 °C, 9 pH for 90 min. Ultraviolet–visible spectroscopy confirmed the synthesis of AgNPs by observing the absorption peak at 422 nm. Crystallographic nature of AgNPs was proved by XRD spectrum. FE-SEM images exhibited that most of AgNPs were spherical in shape with 20–60 nm average size. FT-IR spectrum revealed the existence of secondary metabolites that were involved in the reduction, stabilization and capping of AgNPs. The synthesized AgNPs exhibited the strong bioefficacy against the 3rd instar larvae of Anopheles stephensi (LC50, 6.03; LC90, 10.86 ppm), Aedes aegypti (LC50, 8.29; LC90, 13.75 ppm) and Culex quinquefasciatus (LC50, 16.55; LC90, 36.81 ppm) after 72 h of exposure. The AgNPs also exhibited strong anti-cancer activity having IC50 value 1.129 μg/ml after 24 h. These were proved to be non-toxic against non-target organism and normal cell line. These results suggest that synthesized AgNPs have strong larvicidal and anti-cancer potential and thus can be employed in cancer therapy, targeted drug delivery and drug designing.

A comparative study of the anodic alumina film thickness measured via SEM and evaluated using Faraday’s Law

Five Al specimens (99.301 wt% pure) were anodized in 0.3 M oxalic acid at 0 °C and 40 V for five different anodization times in the range 5–30 min. The thickness of the anodic alumina films was measured by SEM as well as calculated by Faraday’s Law. It was found that the average current (4.71 mA), average current density (2.14 mA cm−2), and average growth rate (57.37 nm min−1) of the anodic alumina films remain independent of anodization time. The total charge transferred (1.42–8.16 C) and thickness of alumina film calculated by Faraday’s Law (0.29–1.66 μm) increase linearly with the increase in anodization time from 5 to 30 min. It was established that the value of film thickness measured by SEM (5–79 μm) also increases linearly with the anodization time. However, the value of was substantially greater than that of The relation between and can be described by = R (t, V, T) × where the value of multiplying factor R depends on the anodization time (t), voltage (V), and temperature (T). Analysis of the SEM top-view image micrographs of the anodic alumina films revealed that the pore diameter, interpore distance, and porosity of the anodic alumina film increase linearly with the increase in the anodization time. On the contrary, opposite behavior was observed in the case of pore circularity and pore density. The peak intensity of preferentially oriented (311) plane of Al substrate decreased whereas the FWHM increased on anodization, which means that the crystallographic nature of (311) plane was rather deteriorated on anodization.

Biosynthesis and Characterization of Iron Oxide Nanoparticles via Syzygium aromaticum Extract and Determination of Its Cytotoxicity against Human Breast Cancer Cell Lines

Magnetic iron oxide nanoparticles exhibit many interesting properties due to their surface chemistry and they can be exploited in biomedical and technological applications. The iron oxide nanoparticles (FeO NPs) using ferric chloride, ferrous chloride, PVP (Poly Vinyl Pyrolidone) and <i>Syzygium aromaticum</i> extract were successfully synthesized by wet-chemical co-precipitation method. The PVP coated FeO NPs and <i>S. aromaticum</i> loaded to PVP coated FeO NPs were systematically characterized by using expository tools. UV-Visible spectroscopy showed the maximum absorbance at 480 nm and 554 nm due to the excitation of surface plasmon vibrations in the FeO NPs formation. Fourier transform infrared (FT-IR) spectrum showed the presence of functional groups of in the form of various band positions and this study confirmed that phenols and primary amines were majorly present. DLS studies revealed narrow size of particles i.e., 399.8 nm and 190.1 nm. Particle size distribution was showed at 256 nm and 153 nm for these samples and zeta potential values were observed at -23.7 and -18.8 mV with greater stability. The X-ray diffraction (XRD) analysis is in good agreement with a high degree of crystallographic nature of particles and the average particle size was found to be 23 nm and 29 nm using Scherrer equation. FT-Raman spectrum showed three main characteristic peaks. The scope of this study was extended by examining the cytotoxicity of PVP coated FeO NPs and S. aromaticum loaded PVP coated FeO NPs on human breast (MCF-7) cancer cell lines. The results suggest that the <i>S. aromaticum</i> loaded FeO NPs acts as a potential anti-cancer agent and are a promising research field for lots of biomedical applications particularly for breast cancer studies.<div><br></div>

Impact of Hydrogen Content on the Thermal Stability of Hydride Phases in Zirconium Alloys

The fast and spontaneous hydrogen diffusion in HCP structures leads to the hydride precipitation. It is often pointed as causing embrittlement and rupture in zirconium alloys for applications in the nuclear industry. In our previous works TEM, DSC, SEM-EBSD and XRD were used to study the hydride stability after many precipitation-dissolution thermal cycles as well as the crystallographic hydride phase nature and the hydride-substrate crystallographic orientation relationships as a function of the hydrogen content. Results showed that the evolution of the dissolution and precipitation energies is correlated to the concentration of hydrogen atoms available to reprecipitate, which is submitted to a diffusion controlled by the misfit dislocation migration. In the present work in-situ TEM thermal cycling was performed in order to locally investigate the crystallographic stability of zirconium hydrides of different structures after many dissolution-reprecipitation cycles.

Revealing abnormal {11[formula omitted]1} twins in commercial purity Ti subjected to split Hopkinson pressure bar

The deformation behavior of Ti alloys during conventional deformation, such as rolling and compression, have been extensively investigated, while it is less understood during high strain rate deformation. In the present work, a commercial purity (CP) Ti alloy was subjected to high strain rate (∼600 s−1) compression deformation using a split Hopkinson pressure bar (SHPB) system. By multi-impacts, an accumulative deformation strain of ∼0.15 was achieved. The microstructural evolution has been systematically analyzed by electron backscatter diffraction (EBSD). It is found that the CP-Ti alloy has been deformed predominantly by three different twinning modes, {101¯2} (T1), {112¯1} (T2) and {112¯2} (C1). A large fraction of the {112¯1} (T2) twin boundary (TB) segments are found to be in connection with deformation band (DB) boundary segments with misorientation angles much lower than the theoretical value of the {112¯1} (T2) TB, ∼35°. Based on the analysis of the crystallographic nature of these abnormal {112¯1} (T2) TBs and the calculation of Schmid factor, it is suggested that these abnormal {112¯1} (T2) TBs are evolved from DB boundaries through the accumulative slip of single basal-〈a〉 dislocations, namely a kinking mechanism. This special twinning mode of the {112¯1} (T2) twin has been attributed to the high strain rate deformation during SHPB compression, which is helpful for understanding the deformation and twinning behavior during high strain rate deformation.

Facile synthesis of Au and Ag nanoparticles using fruit extract of Lycium chinense and their anticancer activity

A simple green approach for the synthesis of gold (Au) and silver (Ag) nanoparticles was prepared using Lycium chinense (LC) fruit extract as a reducing and stabilizing agent. The synthesized nanoparticles (NPs) were characterized by relevant surface plasmon resonance peaks for gold and silver nanoparticles at 536 and 480 nm, respectively, with an ultraviolet–visible spectrophotometer. The confirmation of gold and silver elements in the synthesized NPs with maximum distribution profiles and the crystallographic nature of the synthesized NPs were confirmed using energy dispersive X-ray spectroscopy, elemental mapping, and X-ray diffraction analysis. LC-prepared silver NPs (LC-AgNPs) antimicrobial activity demonstrated inhibitory activity against pathogenic microorganisms such as Escherichia coli and Staphylococcus aureus. The synthesized LC-prepared gold NPs (LC-AuNPs) did not show inhibitory activity. The LC-AgNPs exhibited significant cytotoxicity to the human breast cancer MCF7 cell line and less cytotoxicity to non-diseased RAW264.7 (murine macrophage) cells, whereas LC-AuNPs showed minimal toxicity to both cell lines. The rapidly synthesized NPs could play a role in the field of nanotechnology and in biomedical applications.

A Revisit to the Notation of Martensitic Crystallography

As one of the most successful crystallographic theories for phase transformations, martensitic crystallography has been widely applied in understanding and predicting the microstructural features associated with structural phase transformations. In a narrow sense, it was initially developed based on the concepts of lattice correspondence and invariant plane strain condition, which is formulated in a continuum form through linear algebra. However, the scope of martensitic crystallography has since been extended; for example, group theory and graph theory have been introduced to capture the crystallographic phenomena originating from lattice discreteness. In order to establish a general and rigorous theoretical framework, we suggest a new notation system for martensitic crystallography. The new notation system combines the original formulation of martensitic crystallography and Dirac notation, which provides a concise and flexible way to understand the crystallographic nature of martensitic transformations with a potential extensionality. A number of key results in martensitic crystallography are reexamined and generalized through the new notation.

Nano-Deformation Behavior of a Thermally Aged Duplex Stainless Steel Investigated by Nanoindentation, FIB and TEM

Nanoindentation and electron backscattering diffraction were conducted on a thermally aged duplex stainless steel to investigate the effect of crystal orientation on the plastic deformation behavior during indentation testing. Both nanohardness H and indentation modulus E are correlated with the orientation factor averaged over three normal directions of the contact surface. After thermal aging, the orientation dependence of the hardness and indentation modulus in ferrite significantly changed. For both the ferrite and austenite phases, the maximum and minimum values of the hardness and indentation modulus are given by the near- $$\left\langle {111} \right\rangle$$ and near- $$\left\langle {001} \right\rangle$$ -oriented grains, respectively. The TEM analysis results indicate that the area of plastic deformation in the ferrite grain decreases after thermal aging. The interactions between precipitates and dislocations are considered to be responsible for the degradation of plastic deformation ability in ferrite. The anisotropy of hardness is related to the crystallographic nature and shearing mechanisms.

A full-field crystal plasticity study on how texture and grain structure influences hydrostatic stress in thermally strained β-Sn films

The present study uses full-field thermo-mechanically coupled crystal plasticity to simulate the stress distribution in thermally strained β-Sn films to better understand the conditions causing the generally rare nucleation of whiskers from such films. Following the notion that stress-driven diffusion along the grain boundary network is leading to and supporting whisker formation, the goal is to identify critical factors of crystallographic and/or geometric nature that influence the hydrostatic stress in such films prior to the onset of actual whisker formation. Approximating the film as a periodic structure of around a hundred columnar grains on an isotropic substrate, the simulations reveal a strong spatial variation of hydrostatic stress over distances comparable to the grain size but without apparent long-range gradients, suggesting whisker nucleation to be a phenomenon that depends on specifics within a relatively small neighborhood of grains. Furthermore, neither the grain size distribution nor the presence of oblique surface grains alters the width of the stress distribution by much. In contrast, the variation of hydrostatic stress notably depends on the crystallographic texture of the film, where β-Sn films for which the film normal is aligned with ⟨0 0 1] show a narrower distribution than films with ⟨1 0 0] parallel to the normal. The former film texture, therefore, is predicted to be less prone to whisker formation than the latter.

Green synthesis of silver nanoparticles from aqueous leaf extract of Pomegranate (Punica granatum) and their anticancer activity on human cervical cancer cells

Plants contain different important phytochemicals that can be used as a potential treatment for various ailments including cancer. The green synthesis of silver nanoparticles from the extract of different plant parts has gained a wide range of engrossment among the researchers due to its unique optical and structural property. The aim of this study is green synthesis of silver nanoparticles from the aqueous leaf extract of pomegranate (Punica granatum) and to investigate its anticancer activity on human cervical cancer cells (HeLa). The synthesis of silver nanoparticle was depicted by the colour change from golden yellowish to dark brownish, UV-visible spectral analysis gave a characteristic surface plasmon absorption peak at . Further morphological characterization was done by Zeta potential where the size analysis was depicted to be 46.1 nm and zeta potential as . Fourier transform infrared spectroscopy (FTIR) inferred 3 intense sharp peaks at , , , confirmed the presence of flavonoids and polyphenols. The scanning electron microscopy (SEM) analysis with energy diffraction spectroscopy (EDS) confirmed the presence of silver nanoparticles with size ranged from to . X-ray diffraction (XRD) confirmed the crystallographic nature of silver. The cell proliferation activity of nanoparticles was tested by 3, −4, 5 dimethylthiazol-2,5 diphenyl tetrazolium bromide (MTT) assay where the inhibitory concentration () was found at inhibiting of HeLa cell line. The anticancer activity of nanoparticles was determined by lactate dehydrogenase (LDH) assay where showed of cytotoxicity. Furthermore, the anticancer property of nanoparticles was confirmed by the DNA fragmentation assay.

Crystallographic Features and Nature of Luminescence Centres of the Niobate and Tantalate Compounds with Layered Perovskite-Like Structure

Aim and Objectives The ultrafine powders of the perovskite-like layered AII3LaM3O12 (AII = Sr, Ba; M = Nb, Ta) compounds have been synthesized by heat treatment of co-precipitated hydroxy-carbonates. The luminescence of these compounds is reported for the first time. Methods: Luminescence spectra of all studied compounds are complex and contain two main wide bands with maxima near 2.9 and 2.5 eV. These luminescence bands were assigned to radiation electron transitions in the MoO67- molecular groups of different symmetry located in the various lattice positions. Conclusion: The energy levels scheme of the MoO67- group and related radiation and absorption transitions had been proposed.

Synthesis, surface chemistry and pseudocapacitance mechanisms of VN nanocrystals derived by a simple two-step halide approach

Chloroamide precursors generated via a simple two-step ammonolysis reaction of transition metal chloride in the liquid phase at room temperature were heat treated in ammonia at moderate temperature to yield nano-sized VN crystallites. Grain growth inhibited by lowering the synthesis temperature (≈400 °C) yielded agglomerated powders of spherical crystallites of cubic phase of VN with particle sizes as small as 6 nm in diameter. X-ray diffraction, FTIR, mass spectroscopy (MS), and nuclear magnetic resonance (NMR) spectroscopy assessed the ammonolysis and nitridation reaction of the VCl4-NH3 system. X-ray Rietveld refinement, the BET technique and high-resolution transmission microscopy (HRTEM), energy dispersive X-ray (EDX) and thermogravimetric analysis (TGA) helped assess the crystallographic and microstructural nature of the VN nanocrystals. The surface chemistry and redox reaction leading to the gravimetric pseudo-capacitance value of (≈855 F/g) measured for the VN nanocrystals was determined and validated using FTIR, XPS and cyclic voltammetry analyses.

A study on the wetting properties of broccoli leaf surfaces and their time dependent self-healing after mechanical damage.

Plants are protected from the elements by a complex hierarchical epicuticular wax layer which has inspired the creation of super-hydrophobic and self-cleaning surfaces. Although many studies have been conducted on different plant wax systems to determine the mechanisms of water repulsion hardly any have studied the recovery of the epicuticular wax layer. In the current study the wetting properties and crystallographic nature of the wax surface of Brassica oleracea var. italica (broccoli) has been studied, as well as the time-dependent recovery of the surface after mechanical damage. It was found that the surface of the broccoli leaves is not only super-repulsive and self-cleaning in regards to water but also in regards to glycerol and formamide, both of which have considerably lower surface tension values. Furthermore, it was shown that the surface properties do indeed recover after damage and that this recovery is multi-stepped and strongly dependent on the recovery of the roughness of the surface.

Self-Organized Growth of Crystallographic Macropores in Multicrystalline Zn by Nanoscale Sculpturing

The self-organized formation of crystallographically oriented macropores in multicrystalline Zn is presented in the present paper. These pores are obtained by pulsed-potential electrochemical etching in an aqueous KCl electrolyte. They exhibit the typical characteristics of crystallographically-oriented pores like growth along certain crystallographic directions, formation of pore domains, branching of pores, and intersections of pores, as observed for e.g. III-V semiconductors such as InP. The pore walls of the pores in Zn are entirely composed of metallic Zn unlike the amorphous metal oxide ones observed in other metals like Al (AAO) or Ti (TiO2). The main pore growth direction in Zn is along <0001>. The branching of side pores occurs along [] and [] in 90° angles from the root pore forming a pore geometry reminding remotely on a monkey puzzle tree. Because of their crystallographic nature of the pores they grow under various angles into the multicrystalline Zn surface depending on the underlying crystal orientation. Like this they form a perfectly suitable structure for mechanical interlocking with polymers. When filled with polymer, the root pores together with the branched side pores act as ideal hooks anchoring the polymer in Zn solving the well-known problem of poor adhesion of polymers and paint on Zn surfaces.

Experimental and Finite Element Analysis of Asymmetric Rolling of 6061 Aluminum Alloy Using Two-Scale Elasto-Plastic Constitutive Relation

AbstractThe goal of this work was theoretical and experimental study of micro- and macroscopic mechanical fields of 6061 aluminum alloy induced by the asymmetric rolling process. Two-scale constitutive law was used by implementing an elasto-plastic self-consistent scheme into the Finite Element code (ABAQUS/Explicit). The model was applied to study the asymmetric rolling. Such a deformation process induces heterogeneous mechanical fields that were reproduced by the model thanks to the crystallographic nature of constitutive law used. The studied material was processed, at room temperature, in one rolling pass to 36% reduction. The resulting material modifications were compared with predictions of the two-scale model. Namely, the calculated textures were compared with experimental ones determined by X-ray diffraction. Especially, detailed quantitative analysis of texture variation across the sample thickness was done. The influence of this texture variation on plastic anisotropy was studied. The advantages of asymmetric rolling process over symmetric one were identified. The main benefits are a nearly homogeneous crystallographic texture, reduced rolling normal forces and homogenization of plastic anisotropy through the sample thickness.

Nanostructure and nanomaterial characterization, growth mechanisms, and applications

Abstract Nanostructures are playing significant roles in the development of new functions and the enhancement of the existing functions of industrial devices such as sensors, transistors, diodes, lithium-ion batteries, and photovoltaic cells, due to their piezoelectricity, biocompatibility, and pyroelectrical characteristics. This research focused on the review of the characteristics of different nanostructures and nanomaterials such as ZnO, ZnS, MoS2, GO, TiO2, SnO2, and Fe2O3, their fabrication techniques, growth mechanisms, and applications. The factors affecting the growth mechanisms, the crystallographic natures, growth models of anisotropic nanostructures, and growth of nanocrystals, were also highlighted in this research. The existence of lattice mismatch, differential thermal expansion, and high deposition temperature, have affected uniform deposition of nanoparticles on substrates and caused heteroepitaxy, which has resulted in defective nanostructures. Although heteroepitaxy has negatively affected the characteristics and potential applications of nanostructures, it has also opened new research frontiers for potential new applications of nanostructures. The use of nanostructures for gas sensing is attributed to the high specific area, change of resistance on exposure to gases, and high photoconduction abilities, while the photon-carrier collection abilities and anti-reflectance qualities are vital for solar photovoltaic cells. Nanostructures have also been used as coating pigments to prevent corrosion of facilities, reduce urban heat islands and energy consumptions, due to the near infrared (NIR) reflective characteristics.

Understanding Morphology Evolution in Lithium Electrodeposition

Lithium-ion batteries are poised to play an important role in the push for electric vehicles. Electroplating and possible dendritic growth, however, have been a safety concern. Non-uniform electrodeposition and subsequent growth may cause short circuit. Apart from catastrophic failure, Li plating results in the battery performance decay as well. There is a need for a better understanding of the factors that are most critical in the nucleation and growth of Li electrodeposition and the morphology evolution thereof. The metal ion reaches the electrode surface where it is reduced. The metal atom can thereafter diffuse inside the bulk electrode or aggregate on the surface under some specific set of conditions and form a variety of structures on the electrode surface, like small islands, uniform film, mossy or filament like structure or dendrite (as schematically shown in Figure 1). Physicochemical determinants affecting electrodeposition include the adsorption energy of metal atom on electrode surface, diffusion barrier for metal atom in the bulk electrode compared to that on the electrode surface, the crystallographic nature of the electrode surface, the strength of cohesive metal-metal interaction. Beyond the nature of the electrode material, the operating temperature, current density and applied potential can also affect the electrodeposition rate, which consequently control the morphology evolution. In this study, a mesoscale interfacial modeling and analysis is presented in order to investigate the lithium electrodeposition regimes and morphology evolution. Figure 1

Bioinspired green synthesis of copper oxide nanoparticles from Syzygium alternifolium (Wt.) Walp: characterization and evaluation of its synergistic antimicrobial and anticancer activity

In recent times, nanoparticles are attributed to green nanotechnology methods to know the synergistic biological activities. To accomplish this phenomenon, present study was aimed to synthesize copper oxide nanoparticles (CuO NPs) by using Syzygium alternifolium stem bark, characterized those NPs using expository tools and to elucidate high prioritized antimicrobial and anticancer activities. Synthesized particles exhibited a color change pattern upon synthesis and affirmed its respective broad peak at 285 nm which was analyzed through UV–vis spectroscopy. FT-IR study confirmed that phenols and primary amines were mainly involved in capping and stabilization of nanoparticles. DLS and Zeta potential studies revealed narrow size of particles with greater stability. XRD studies revealed the crystallographic nature of particles with 17.2 nm average size. Microscopic analysis by using TEM revealed that particle size range from 5–13 nm and most of them were spherical in shape, non-agglomerated and poly-dispersed in condition. Antimicrobial studies of particles showed highest inhibitory activity against E. coli and T. harzianum among bacterial and fungal strains, respectively. The scope of this study is extended by examining anticancer activity of CuO NPs. This study exhibited potential anticancer activity towards MDA-MB-231 human breast cancer lines. Overall, these examinations relate that the S. alternifolium is described as efficient well-being plant and probabilistically for the design and synthesis of nanoparticles for human health. This study paves a way to better understand antimicrobial and anticancer therapeutic drug potentials of nanoparticles to design and analysis of pharmaceuticals by in vivo and in vitro approaches.

Identification of Mo-based Precipitates in Haynes 282 Superalloy

Electron microscopy analyses were used to unambiguously identify the crystallographic nature of the largely speculated about Mo-based and carbon-rich intergranular precipitates in a newer γ′ precipitation strengthened nickel-based superalloy, Haynes 282.

Modelling the transport of geometrically necessary dislocations on slip systems: application to single- and multi-crystals of ice

A model based on the elastic theory of continuously distributed dislocations, accounting for the transport of geometrically necessary dislocations (GND) on slip systems is developed. It allows keeping the crystallographic nature of glide by allocating velocities specific to slip systems to GND. At grain boundaries, the dislocation transport equation is resolved between a specific system in a grain and a specific system in the adjacent grain. It is used to simulate a compression creep test followed by unloading of a multiple slip deforming multi-crystal of ice during which kink band formation, grain boundary migration and localized grain nucleation are observed. The model predictions are compared to 2D strain fields obtained by digital image correlation and show a good agreement. Besides, the kink band position corresponds very well with an area of strong lattice misorientation predicted by the model and is also bounded by opposite densities of edge dislocations, in agreement with kink banding theory and characterization. Furthermore, the grain boundary migration is observed to happen from predicted low dislocation density area towards high dislocation ones—also in agreement with the theory. Lastly, the triple junctions where nucleation is observed are also characterized by high GND density and especially strong gradient of elastic energy density. These different features show the relevance of using a continuum theory of polarized dislocations per slip system to study the onset of relaxation mechanisms like kink banding, grain boundary migration and grain nucleation and possibly to propose nucleation and migration criteria.