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Phenomenal profiling functions were applied for the simulation of an X-ray diffraction (XRD) pattern of pyrite ash bioprocessed in Acetobacter aceti contained growth media. The full width at half maximum (FWHM) values were estimated for each pattern of pyrite ash, and the Bragg equation was used to determine the atomic layer spacing, as well crystallite size and strain broadening were accomplished by applications of Scherrer and Williamson-Hall equations. Errors in line broadening were correlated with the FWHM equations of the generalised profiling functions, and the microstrain (ε) was estimated with the relation between the integral breadth (βi) and cosθ. Furthermore, the XRD pattern of a discrete peak was 3D simulated using Gaussian, Lorentzian, Pearson VII, pseudo-Voigt, and Voigt functions. The Gaussian function with a round top peak was designated the most suitable profile simulation by offering the maximum peak height, Imax and tails comparable to the experimental peak.

The Nickel ferrite has been synthesized by co-precipitation method. X-ray diffraction pattern confirms the formation of cubic spinel structure with lattice constant 8.347Å. Structural properties like X-ray density, average crystalline size, bond length, dislocation density and microstrain have been studied. The scanning electron microscope images show grain of bead structures. The Fourier transform infrared spectroscopy spectrum of nickel ferrite under investigation reveals the formation of a cubic spinel structure showing two significant absorption bands, corresponding to high frequency band ν1and low frequency band ν2arising from tetrahedral (A) and octahedral (B) interstitial sites respectively. [ABSTRACT FROM AUTHOR]

Hexagonal zinc oxide nanorods (ZnO-NRs) were prepared via solution process using zinc nitrate hexahydrate (Zn(NO3)2·6H2O, 0.25 M), hexamethylenetetramine (HMT) and sodium hydroxide at low concentration (4 × 10-3 M in 100 ml of distilled water) and refluxed at 100 °C for an hour. The HMT was used because its act as a template for the nucleation and growth of zinc oxide nanorods. The X-ray diffraction patterns (XRD) clearly reveal that the grown product is pure zinc oxide. The diameters and lengths of the synthesized nanorods lie between 200 and 250 nm and 2–3 μm respectively as observed from the field emission scanning electron microscopy (FESEM). The chemical functional properties was analyzed by Fourier Transform infra-red (FTIR) spectroscopy. This study was designed to show the possible effect of ZnO-NRs in human liver cancer (HepG2) cells. It induces cytotoxicity via reactive oxygen species (ROS), mitochondrial membrane potential. For gene expression analysis, it induces apoptotic gene marker P53, Bax, caspase3, Bcl2 genes. Based on analysis and observations, it concludes that the ZnO-NRs were utilized for toxicity at dose dependent via ROS generation against human hepato cellular liver carcinoma cell line.

Computer image recognition (CIR) on the diffraction patterns of X-ray single crystal diffractometer was used to assist the analysis of the unit cell parameters in terms of lattice volume. This method can improve the prediction accuracy of unit cell parameters in the pre-experiment step since erroneous prediction by the software may occur for 5% tested crystal samples, which may critically affect the complete crystal data quality and cause unnecessary testing time. In the imaging processing, the diffraction pattern images saved as .img format files were firstly batch transferred into .jpg format with high quality for further treatment. Specific features of the crystal diffraction points or zones in the images were extracted for the recognition processing by color mode. The Findcontour algorithm and the Canny algorithm based on Gaussian filtering were used for the diffraction peak points and area detection. The relationship between the distribution of crystal diffraction points (DCDP) and the lattice volumes based on reciprocal lattice theory was established for the users to judge the reasonable location range of the lattice volumes. A Density model was proposed to correlate the dependence of the DCDP and the experimental data. Special crystal samples were chosen to test the CIR performance, and its accuracy for the lattice volume prediction was evaluated. The CIR method can be used for the assistance in the analysis of the lattice volume location range and for crystal structure solving.

The present studies have mainly been focused on the development (synthesis and characterization) of eco-friendly co-substituted (Ni, Ti) bismuth ferrite (referred as BFO) multiferroic of a composition Bi(Ni0.35Ti0.35Fe0.30)O3. The structural and morphological features of the ceramic technology prepared material were first examined by powder X-ray diffraction and field-emission scanning electron microscopy (FE-SEM) techniques. It is found that the Fe-site co-substitution has created deformation in structure of BFO from rhombohedral to orthorhombic symmetry. Their crystallite size was estimated by the Scherrer's technique and found to be in the range of 20–49 nm. Detailed analysis of the FE-SEM micrograph and EDX (energy-dispersive X-rays) spectrum has shown the (i) uniform distribution of grains of varying size and (ii) elemental content and composition of the Bi(Ni0.35Ti0.35Fe0.30)O3 compound. Studies of the dielectric-impedance spectroscopy and transport parameters, obtained in a broad range of temperatures (298–773 K) and frequency (1 kHz–1 MHz), have provided many important data and mechanism, such as dielectric dispersion at high temperature, conduction mechanism, transport properties, non-Debye type of relaxation processes and negative temperature coefficient behavior of resistance (NTCR) of the studied material. The polarization vs. electric field (hysteresis loop) analysis exhibits that the magnitude of polarization increases with the increase of applied electric field. The magnetic measurement shows the change in ferromagnetic properties which may be due to the observed high remanent magnetization and coercive field. Thus, prepared material with modified multiferroic features may lead to numerous applications in the field of transducers, sensors and electronic industry. [ABSTRACT FROM AUTHOR]

The present studies have mainly been focused on the development (synthesis and characterization) of eco-friendly co-substituted (Ni, Ti) bismuth ferrite (referred as BFO) multiferroic of a composition Bi(Ni0.35Ti0.35Fe0.30)O3. The structural and morphological features of the ceramic technology prepared material were first examined by powder X-ray diffraction and field-emission scanning electron microscopy (FE-SEM) techniques. It is found that the Fe-site co-substitution has created deformation in structure of BFO from rhombohedral to orthorhombic symmetry. Their crystallite size was estimated by the Scherrer's technique and found to be in the range of 20–49 nm. Detailed analysis of the FE-SEM micrograph and EDX (energy-dispersive X-rays) spectrum has shown the (i) uniform distribution of grains of varying size and (ii) elemental content and composition of the Bi(Ni0.35Ti0.35Fe0.30)O3 compound. Studies of the dielectric-impedance spectroscopy and transport parameters, obtained in a broad range of temperatures (298–773 K) and frequency (1 kHz–1 MHz), have provided many important data and mechanism, such as dielectric dispersion at high temperature, conduction mechanism, transport properties, non-Debye type of relaxation processes and negative temperature coefficient behavior of resistance (NTCR) of the studied material. The polarization vs. electric field (hysteresis loop) analysis exhibits that the magnitude of polarization increases with the increase of applied electric field. The magnetic measurement shows the change in ferromagnetic properties which may be due to the observed high remanent magnetization and coercive field. Thus, prepared material with modified multiferroic features may lead to numerous applications in the field of transducers, sensors and electronic industry. [ABSTRACT FROM AUTHOR]

Abstract The study investigates Curie temperature (T C), bulk magnetic susceptibility, hysteresis, and X-ray diffraction pattern of in situ target basalts of Lonar impact crater, India. The main magnetic phase in the target basalt is low-Ti titanomagnetite. This study reveals an increase in T C and decrease in magnetic susceptibility and in full width at half maxima of the 311 peaks of titanomagnetite with distance from the crater center. Changes in crystal lattice of titanomagnetite, such as straining of 311 peaks, decrease in apparent crystallite size, and grain fragmentation may be among the possible reasons for the observed trends in T C and magnetic susceptibility. However, they both do not show any correlation between each other, indicating that different shock-induced processes affect them.

In this work, titanium carbide (TiC) nanoparticles have been successfully synthesized at much lower temperatures of 500°C using cheaper starting materials, such as waste polytetrafluoroethylene (PTFE) (carbon source) and titanium and metallic sodium, than the traditional carbothermal reduction of TiO2 at 1,800°C. An XRD pattern proved the formation of face-centered cubic TiC, and TEM images showed the obtained TiC nanoparticles with an average size of approximately 50 nm. In addition, the separator coated with TiC nanoparticles as an active material of interlayer effectively mitigates the shuttling problem by taming the polysulfides in Li–S batteries compared with a traditional celgard separator. The assembled cell realizes good cycling stability with 501 mAh g−1 and a low capacity fading of 0.1% per cycle after 300 cycles at 1 C due to high utilization of the sulfur-based active species.

Phenomenal profiling functions were applied for the simulation of an X-ray diffraction (XRD) pattern of pyrite ash bioprocessed in Acetobacter aceti contained growth media. The full width at half maximum (FWHM) values were estimated for each pattern of pyrite ash, and the Bragg equation was used to determine the atomic layer spacing, as well crystallite size and strain broadening were accomplished by applications of Scherrer and Williamson-Hall equations. Errors in line broadening were correlated with the FWHM equations of the generalised profiling functions, and the microstrain (ε) was estimated with the relation between the integral breadth (βi) and cosθ. Furthermore, the XRD pattern of a discrete peak was 3D simulated using Gaussian, Lorentzian, Pearson VII, pseudo-Voigt, and Voigt functions. The Gaussian function with a round top peak was designated the most suitable profile simulation by offering the maximum peak height, Imax and tails comparable to the experimental peak. [ABSTRACT FROM AUTHOR]

The optimization of secondary phase in thermoelectric (TE) materials can help to improve the efficiency of the material. Being a potential candidate for lower temperature TE application, bismuth telluride (Bi2Te3) nanoparticles were synthesized via different routes and profiles to optimize their pure single phase. Systematic characterizations were performed with the help of X-ray diffraction (XRD), Rietveld refinement, and field effect scanning electron microscopy (FE-SEM) for structural and morphological behaviors, while TE properties such as Seebeck coefficient, electrical conductivity, and power factor were measured for the purest sample chosen. Rietveld refinement in the XRD pattern of the samples revealed that only a small amount (∼ 1.6%) of Bi2Te3 was formed in the coprecipitation method, while the hydrothermal technique increases this phase with increment in synthesis duration. This work focused on the phase evolution of Bi2Te3 with increasing synthesis duration time at constant temperature and vice versa. XRD and Rietveld refinement revealed that the hydrothermal technique (150°C for 48 h) can synthesize purest samples (84% Bi2Te3 phase in this case). FE-SEM and energy-dispersive X-ray analysis also indicated that the impure phase in the system is decreased along with an atomic percentage of oxygen from 37% to 11% and decreases in particle size with increase in temperature in case of hydrothermally synthesized samples. Decrease in the size of the particle, with an increase in synthesis temperature, shows a decrease in percentage abundance of Bi2Te3 phase due to surface Te desorption. The observed electrical conductivity is ∼20 times greater, while Seebeck coefficient is ∼3 times lower than that of the pure Bi2Te3 phase. The detailed analysis has generalized the growth mechanism in Bi2Te3 phase evolution by the diffusion of Bi into Te nanorods to fabricate hexagonal Bi2Te3, and Te-desorption from the surfaces of these particles.

The effect of the polycarboxylate ether and the complex hydrophobic-plasticizing additive on the structure, phase and mineral composition of cement based on polymineral clay with content of relict minerals more than 85 % (52.49 % of quartz) was studied. As research methods chosen X-ray diffraction pattern, differential scanning calorimetry and scanning electron microscopy. The regularities of the effect of the complex hydrophobic-plasticizing additive based on polycarboxylate ether and octyltriethoxysilane on the formation of cement hydration products in a strengthened clayey soil are established. Changes in structure and composition include the following: the formation of a strong skeleton of the crystallization phase due to the increase in the number of hydrated new formation in the form of low-basic hydrated calcium silicate and ettringite, decrease in portlandite content, as well as an increase in the amount of amorphous phase (up to 16 %) in the form of tobermorite gel filling intercrystalline spaces. In soil-cement hydrated silicate calcium are formed in an amount of more than 4 % and ettringite in an amount of more than 7 %, the amount of portlandite reduced by 46 %. The result of modification of the complex hydrophobic-plasticizing admixture of soil-cement, a denser and homogeneous structure with a pronounced "overgrowth" of the pores formed by gel-like hydrated calcium silicate is formed, which are deposited in a large amount on the minerals of the strengthened soil.

The microwave dielectric properties of (Mg1-xCox)2SnO4 were investigated by X-ray diffraction (XRD) patterns, Rietveld refinement, Raman spectroscopy, and microstructural observation. As x increased from 0 to 0.05, both the lattice constant and the unit cell volume increased, indicating that the Co2+ ions effectively dissolved among the Mg2+ ions. However, when x exceeded 0.05, the Co2+ ions were not effectively dissolved. The bond length in the oxygen octahedron increased with x. In the Raman spectroscopy, the Raman peak in the A1g vibration mode shifted to a lower frequency as x increased. The (Mg0.95Co0.05)2SnO4 ceramic had the lowest FWHM of the peak in the A1g Raman mode. (Mg0.95Co0.05)2SnO4 ceramic that was sintered at 1550 °C for 4 h had a dielectric constant (εr) of 8.3, a quality factor (Q × f) of 120,200 GHz (at 17.6 GHz), and a temperature coefficient of resonant frequency (τf) of − 63 ppm/°C. [ABSTRACT FROM AUTHOR]

The present study demonstrated the preparation of three different acid‐functionalised magnetic nanoparticles (MNPs) and evaluation for their catalytic efficacy in hydrolysis of cellobiose. Initially, iron oxide (Fe3 O4)MNPs were synthesised, which further modified by applying silica coating (Fe3 O4 ‐MNPs@Si) and functionalised with alkylsulfonic acid (Fe3 O4 ‐MNPs@Si@AS), butylcarboxylic acid (Fe3 O4 ‐MNPs@Si@BCOOH) and sulphonic acid (Fe3 O4 ‐MNPs@Si@SO3 H) groups. The Fourier transform infrared analysis confirmed the presence of above‐mentioned acid functional groups on MNPs. Similarly, X‐ray diffraction pattern and energy dispersive X‐ray spectroscopy analysis confirmed the crystalline nature and elemental composition of MNPs, respectively. TEM micrographs showed the synthesis of spherical and polydispersed nanoparticles having diameter size in the range of 20–80 nm. Cellobiose hydrolysis was used as a model reaction to evaluate the catalytic efficacy of acid‐functionalised nanoparticles. A maximum 74.8% cellobiose conversion was reported in case of Fe3 O4 ‐MNPs@Si@SO3 H in first cycle of hydrolysis. Moreover, thus used acid‐functionalised MNPs were magnetically separated and reused. In second cycle of hydrolysis, Fe3 O4 ‐MNPs@Si@SO3 H showed 49.8% cellobiose conversion followed by Fe3 O4 ‐MNPs@Si@AS (45%) and Fe3 O4 ‐MNPs@Si@BCOOH (18.3%). However, similar pattern was reported in case of third cycle of hydrolysis. The proposed approach is considered as rapid and convenient. Moreover, reuse of acid‐functionalised MNPs makes the process economically viable. [ABSTRACT FROM AUTHOR]

The microwave dielectric properties of (Mg0.93Ni0.07)2SnO4 ceramics were examined with a view to their exploitation for wireless high-temperature dielectric resonator antenna temperature sensor. A dielectric constant of 8.1, a quality factor of 124,200 GHz, and a temperature coefficient of the resonant frequency of −67 ppm/°C were obtained for (Mg0.93Ni0.07)2SnO4 ceramics that were sintered at 1550 °C for 4 h. The developing procedures and test results for dielectric resonator antenna temperature sensor were recorded. The resonating frequency and 3 dB bandwidth measured at 25 °C were 12.62 GHz and 53 MHz, respectively. A sensitivity of −0.99 MHz/°C was successfully achieved. [ABSTRACT FROM AUTHOR]

In this work, a new BN polymorph with Pnma symmetry is proposed by RG2 and investigated by density functional theory. Pnma -II BN polymorph is shown to be dynamically and mechanically stable, and the relative enthalpy of Pnma -II BN is 0.187 eV per atom higher than that of c-BN, respectively. Mechanical properties calculations indicate that Pnma -II BN is also a potential superhard material with hardness of 49.7 GPa. The electronic band structures of Pnma -II BN show that the Pnma -II BN is a direct and ultrawide band gap semiconductor (band gap is 5.82 eV). The mechanical anisotropy of Young's modulus of Pnma -II BN and Pnma BN is greater than that of c-BN, while the mechanical anisotropy of shear modulus of Pnma -II BN in the (100), (001) plane is lower than that of c-BN. In addition, simulated X-ray diffraction patterns are provided for experimental confirmation of the predicted structures. [Display omitted] [ABSTRACT FROM AUTHOR]

The study investigates Curie temperature (TC), bulk magnetic susceptibility, hysteresis, and X-ray diffraction pattern of in situ target basalts of Lonar impact crater, India. The main magnetic phase in the target basalt is low-Ti titanomagnetite. This study reveals an increase in TC and decrease in magnetic susceptibility and in full width at half maxima of the 311 peaks of titanomagnetite with distance from the crater center. Changes in crystal lattice of titanomagnetite, such as straining of 311 peaks, decrease in apparent crystallite size, and grain fragmentation may be among the possible reasons for the observed trends in TC and magnetic susceptibility. However, they both do not show any correlation between each other, indicating that different shock-induced processes affect them. [ABSTRACT FROM AUTHOR]

This work explores the rapid synthesis of silver nanoparticles (AgNPs) from Musa paradisiaca (M. paradisiaca) bract extract. The bio‐reduction of Ag+ ion was recorded using ultraviolet–visible spectroscopy by a surface plasmon resonance extinction peak with an absorbance at 420 nm. The phytoconstituents responsible for the reduction of AgNPs was probed using Fourier transform infrared spectroscopy. The X‐ray diffraction pattern confirmed the formation of crystalline AgNPs that were analogous to selected area electron diffraction patterns. Morphological studies showed that the obtained AgNPs were monodispersed with an average size of 15 nm. The biologically synthesised AgNPs showed higher obstruction against tested phytopathogens. The synthesised AgNPs exhibited higher inhibitory zone against fungal pathogen Alternaria alternata and bacterial pathogen Pseudomonas syringae. Free radical scavenging potential of AgNPs was investigated using 1,1‐diphenyl‐2‐picryl hydroxyl and 2,2‐azinobis (3‐ethylbenzothiazoline)‐6‐sulphonic acid assays which revealed that the synthesised AgNPs act as a potent radical scavenger. The catalytic efficiency of the synthesised AgNPs was investigated for azo dyes, methyl orange (MO), methylene blue (MB) and reduction of o‐nitrophenol to o‐aminophenol. The results portrayed that AgNPs act as an effective nanocatalyst to degrade MO to hydrazine derivatives, MB to leucomethylene blue, and o‐nitro phenol to o‐amino phenol [ABSTRACT FROM AUTHOR]

We have studied the effect of microwave processing (power of 700 W, frequency of 2.45 GHz, and duration of 600 s) on the phase and polymorphic transformations of natural clay particles in air and humid media. In iron oxides, hematite (Fe2O3) converts into Fe-cordierite (Fe2Al3[AlSi5O18]) and magnetite (FeO ∙ Fe2O3). The aluminum oxide γ-Al2O3 undergoes a partial polymorphic transformation, and corundum (α-Al2O3) crystallizes from an amorphous phase. Silicon oxides also undergo polymorphic transformations. Of the three silica polymorphs present in natural clay, only two, β-quartz and β-cristobalite, persist after microwave processing in air and only β-quartz persists in a humid atmosphere. The working medium has been shown to influence the nature of the phase transformations. Our results demonstrate the possibility of initiating structural changes in disperse clay systems by microwave processing. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) were prepared by a green method using Cordia myxa leaf extract. They were characterised by UV–vis spectroscopy, Fourier transform infrared spectroscopy and their X‐ray diffraction pattern. Their sizes were determined by scanning electron micrographs, transmission electron micrographs imaging and dynamic light scattering analysis. The shapes of nanoparticles were spherical or truncated triangular and their average size was determined to be 51.6 nm. Their solution was stable at least for one month. The prepared AgNPs were used as a selective chemical sensor for determination of iron(III) (only when Cl− ions were present in the medium) and mercury(II) ions with detection limits of 0.084 and 0.037 nM, respectively. It was shown that the mechanism of these detections is through oxidation of Ag atoms by Fe3+ and Hg2+ ions. [ABSTRACT FROM AUTHOR]

(ZnSe)x(SnSe)1–x films have been produced using chemical molecular beam deposition (CMBD) from an ZnSe and SnSe compound with a stoichiometric composition at a substrate temperature of 500°С. The structural, morphological, and electrophysical properties of (ZnSe)0.1 (SnSe)0.9 films are studied. The size of film grains is 5–6 μm. The results of X-ray diffraction analysis of specimens have revealed that the films have a crystalline (orthorhombic) structure. The structural parameters of the produced films are presented. The electrical conductivity of the films measured using the Van der Pauw method varies within 15–0.6 Ω cm–1. [ABSTRACT FROM AUTHOR]

Based on X-ray diffraction (XRD) pattern of coal, an empirical model for judging the coalification degree is used to calculate the ratio of the 002 peak height to the Full width at half maximum (FWHM). However, the existing models are often simpler and more suitable for judgment of the medium and low rank coal, while are not feasible in determination of high rank coal. In order to address this issue, the objective of this study is to establish a new modified mathematical model based on optimization of the existing empirical models. Through the calculation of Bragg equation, it demonstrates that the low-angle region (2θ = 3-10°) in the XRD pattern reflects the information of micropore in coal with a diameter of (0.884-2.94) nm. Accordingly, its diffraction intensity corresponds to the porosity rate in coal. As a result, the modified mathematical model has been established for characterizing the coalification degree by introducing the variation of porosity rate with the coal ranks creatively. The synergistic effects of the change regulation of organic matter peak and the porosity rate with coal rank ensure the accuracy of the model. Furthermore, the good stability and high reliability of new model are verified through the recalculation of a total of 14 coal samples. Study results demonstrated that the new method enabled to determine coal rank more conveniently and accurately in the industrial production. [ABSTRACT FROM AUTHOR]

For the past 50 years there has been considerable debate over the sub-structure of the fully differentiated (oxidised) trichocyte keratin intermediate filament. Depending on the staining and preparative procedures employed, IF observed in transverse section in the transmission electron microscope have varied in appearance between that of a “ring” and a “ring-core” structure, corresponding to the so-called (8+0) and (7+1) protofilament arrangements. In a new analysis of the fine structure of the 1 nm equatorial region of the X-ray diffraction pattern of quill we show that the observed pattern is consistent with the (8+0) model and we are also able to assign values to the various parameters. In contrast, we show that the observed X-ray pattern is inconsistent with a (7+1) arrangement. Furthermore, in the (7+1) model steric hindrance would be encountered between the core protofilament and those constituting the ring. The appearance of a central “core” in transverse TEM sections, previously attributed to a central protofilament, is explained in terms of portions of the apolar, disulfide-bonded head and/or tail domains of the trichocyte keratin IF molecules, including the conserved H subdomains, lying along the axis of the IF, thereby decreasing the efficacy of the reducing agents used prior to staining. The H1 subdomain, previously shown to be important in the assembly of epidermal IF molecules at the two- to four-molecule level, is likely to have a similar role for the trichocyte keratins and may form part of a central scaffold on which the molecules assemble into fully functional IF. [ABSTRACT FROM AUTHOR]

Environmental pollution and toxicity have been increasing due to the overuse of chemical fertilisers, which has encouraged nanotechnologists to develop eco‐friendly nano‐biofertilisers. The authors demonstrated the effect of biogenic copper nanoparticles (CuNPs) on the growth of pigeon pea (Cajanus cajan L.). The UV–visible analysis showed absorbance at 615 nm. Nanoparticle tracking and analysis revealed particle concentration of 2.18 × 108 particles/ml, with an average size of 33 nm. Zeta potential was found to be −16.7 mV, which showed stability. X‐ray diffraction pattern depicted the face centred cubic structure of CuNPs; Fourier transform infrared spectroscopy demonstrated the capping due to acidic groups, and transmission electron micrograph showed nanoparticles with size 20–30 nm. The effect of CuNPs (20 ppm) on plant growth was studied, for the absorption of CuNPs by plants on photosynthesis, which was evaluated by measuring chlorophyll a fluorescence using Handy‐Plant Efficiency Analyser. CuNPs treatment showed a remarkable increase in height, root length, fresh and dry weights and performance index of seedlings. The overall growth of plants treated with CuNPs after 4 weeks was recorded. The results revealed that inoculation of CuNPs contribute growth and development of pigeon pea due to growth promoting activity of CuNPs. [ABSTRACT FROM AUTHOR]

Silica aerogel is a unique three-dimensional nano-porous material and its characteristics have attracted much attention from both engineers and researchers. However, their structural behaviors under high temperature are not well known yet. The structure of silica aerogel under high temperature from 950 °C to 1200 °C was investigated based on pycnometry, scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET) analysis, Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction patterns (XRD). It was obtained that the structure of silica aerogels was strongly affected by heating temperature and time. It was known based on experimental results that the changes of silica aerogel during 950–1200 °C can be divided into three steps: expansion of primary particles at sample surface (step I), atrophy and pore collapse of primary particles at the surface (step II), and atrophy and pore collapse of primary particles inside the sample (step III). Change rate was found significantly dependent on the moving rate of expansion region, while during the first two steps only limited changes were observed about three dimensional nanoporous structures. During Step III, the structure of silica aerogel was completely destructed, while the density can reach to about 1600 kg/m 3 . [ABSTRACT FROM AUTHOR]

X-ray diffraction peak profile analysis is a powerful method for investigation of the microstructural characteristics of nanocrystalline materials produced by severe plastic deformation. Williamson-Hall method, its modification, and Fourier transform methods like Warren-Averbach and its modification are used to extract microstructural information based on integral breadth and Fourier coefficients of the peak profiles. In this work, pure nickel powders were milled for 2, 5, 20, and 40 h to clarify the microstructural variations for this metal with FCC atomic structure. By using the Williamson-Hall and Warren-Averbach methods and their modifications, crystallite size, microstrain, dislocation density, and character of dislocation were extracted. It was obtained that the fraction of edge-type dislocation decreased with milling time (above 50%), while after prolonged milling, the fraction of screw-type dislocations decreased, so that 50%-edge-to 50%-screw ratio was obtained. It was also found that the values of the crystallite size obtained from classical Warren-Averbach and modified Warren-Averbach (area-average) were closed. [ABSTRACT FROM AUTHOR]

The optimal conditions (υк = 8−9 Å/s; Тп = 673 K) to obtain structurally perfect (W1/2 = 100″−140″) Cd1 − x(Mn, Fe)xSe epitaxial films in the (111) plane are determined. The structure and surface morphology of the epitaxial films are studied. It is established that in Cd1 − x(Mn, Fe)xSe thin films, unlike bulk samples, the sphalerite structure with the lattice parameter a = 6.05 Å is formed. Using an additional source of Se vapor during growth, Cd1 − x(Mn, Fe)xSe epitaxial films with a clean, smooth surface are obtained. [ABSTRACT FROM AUTHOR]

Solvent-free synthesis of [Cu(CH3COO)2(TMP)2](1) and [Ni(CH3COO)2(TMP)2](2) by ball milling of Cu(CH3COO)2.H2O and Ni(CH3COO)2.4H2O with Trimethoprim in the absence of solvent is described. Conventional synthesis of 1. CH3OH and 2. CH3OH was carried out by the reaction of metal acetate salt and Trimethoprim using the solution-based method (reflux in CH3OH for 2 h) for comparison purposes. The mechanochemical products were characterized by comparison of melting points, conductivity values, spectral data, XRPD patterns with those of free ligand and solution based conventional synthesis products. X-ray diffraction patterns of the complex were similar to the simulated pattern of the complex obtained from single crystal structure suggesting the formation of identical compounds as obtained in solvent medium. The process presented here is operationally simple, environmentally benign and affords excellent yields without the need for solvents or external heating. Clearly, it can present a higher efficiency in terms of materials, energy and time compared to classical solution phase synthesis.

Solvent-less synthesis of [Co(CIM)2](SO4) and [Ni(CIM)2](OAC)2 by grinding of CoSO4 and Ni(CH3COO)2.4H2O with cimetidine without any solvent is described. The complexes have been characterized by elemental analysis, melting point, AAS, conductivity measurements, TLC, infrared and UV-Vis spectroscopies as well as X-ray powder diffraction. Cimetidine was found to be bidentate or tridentate ligand. Cobalt ion coordinate with cimetidine through the sulphur atom in the thiol group, nitrogen atom of imidazole ring and the nitrogen atom of the secondary amine to give an octahedral geometry with ligand acting as tridentate whereas nickel ion coordinates through the sulphur atom in the thiol group, nitrogen atom of imidazole ring to give tetrahedral structure with ligand acting as bidentate. X-Ray diffraction patterns of the complex were different from that of the ligand suggesting formation of coordination compounds. The method is quick and gives a quantatively yield, without the need for solvents or external heating. Clearly, it can present higher efficiency in terms of materials, energy and time compared to classical solution phase synthesis.

Abstract This paper presents the fabrication and characterization of zinc oxide micro-flowers and their antibacterial activity. The micro-flowers of zinc oxide composed of hexagonal nanorods have been prepared via solution process using precursor zinc acetate di-hydrate and sodium hydroxide in 3 h of refluxing time at ~90°C. The antibacterial activities of grown micro-flowers were investigated against four pathogenic bacteria namely S. aureus, E. coli, S. typhimurium and K. pneumoniae by taking five different concentrations (5–45 μg/ml) of ZnO micro-flowers (ZnO-MFs). Our investigation reveals that at lowest concentration of ZnO-MFs solution inhibiting the growth of microbial strain which was found to be 5 μg/ml for all the tested pathogens. Additionally, on the basis of morphological and chemical observations, a chemical reaction mechanism of ZnO-MFs composed of hexagonal nanorods was also proposed.

The biosynthesis of silver nanoparticles (AgNPs) has been proved to be a cost effective and environmental friendly approach toward chemical and physical methods. In the present study, biosynthesis of AgNPs was carried out using aqueous extract of Zea mays (Zm) husk. The initial colour change from golden yellow to orange was observed between 410 and 450 nm which confirmed the synthesis of AgNPs. Also, dynamic light scattering‐particle size analysis confirmed the average size to be 113 nm and zeta potential value of −28 kV. The morphology of synthesised Zm AgNPs displayed flower‐shaped structure, X‐ray diffraction pattern revealed the strongest peaks at 2θ = 38.6° and 64° which proved that the nanoparticle has the face centred crystalline structure. The Fourier transform infrared spectroscopy results showed strong absorption bands at 1394.53, 2980.02 and 2980.02 cm−1 due to the presence of alkynes, carboxylic acids, alcoholic and phenolic groups. The maximum zone of inhibition was observed against Salmonella typhi (22 mm) and Candida albicans (18 mm). The synthesised nanoparticles exhibited more free radical scavenging activity than the aqueous plant extract. This is the first report on the synthesis of AgNP from Zm husk, delivers the efficient and stable Zm AgNPs through simple feasible approach toward green biotechnology. [ABSTRACT FROM AUTHOR]

In this study, the authors report a facile synthesis for the formation of nanoscale CoO dots to nanospheres via solution technique at low temperature and characterized in terms of their morphological, structural, compositional, and thermal properties. The morphological characterizations of as-synthesized and annealed CoO structures were done by scanning electron microscopy (SEM) and transmission electron microscopy, which confirmed that synthesized products are very small in size and bears small dots to spheres such as structures. The surface of nanodots is smooth and clean throughout the whole morphology. The crystalline property was analyzed with X-ray diffraction pattern and it reveals that the formed structures exhibit small size and clearly consistent with SEM observation. The compositional and thermal properties of as-synthesized and annealed CoO structures were observedviaFourier transform infrared spectroscopy and Thermogravimetric analysis, which confirmed that synthesized structures are pure CoO and showed good thermal stability. Finally, plausible mechanisms for the formation of CoO nanodots to nanospheres are also discussed. [ABSTRACT FROM AUTHOR]

We have studied the growth and structure of epitaxial films of CdMn ( x = 0.03) diluted magnetic solid solutions grown on mica substrates by molecular beam epitaxy and identified conditions for producing n- and p-type epitaxial films. Using an additional Te vapor source and optimizing the substrate temperature in the growth process, we were able to obtain structurally perfect p-type CdMnTe ( x = 0.03) films with clean, smooth surfaces. The growth plane of the films on the mica substrates is (111) of a face-centered cubic lattice and their unit-cell parameter is а = 6.477 Å. [ABSTRACT FROM AUTHOR]

The authors report the comparative antibacterial activity of silver nanoparticles synthesised by biological (using Fusarium oxysporum) and chemical routes in the presence and absence of pluronic F68 as a stabilising agent. The production of silver nanoparticles was evidenced by UV–visible spectra, with absorbance at about 420 nm in the case of both biological and chemical synthesis. X‐ray diffraction pattern confirmed the presence of face‐centred cubic structure (FCC plane). The nanoparticles characterised by transmission and scanning electron microscopy showed spherical silver nanoparticles with size range of 5–40 and 10–70 nm in the case of biologically and chemically synthesised nanoparticles, respectively. Addition of pluronic F68 showed the stabilisation of silver nanoparticles. Antibacterial efficacy of silver nanoparticles demonstrated different inhibitory activity against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Overall, biologically synthesised silver nanoparticles showed higher activity as compared with chemically synthesised nanoparticles. Silver nanoparticles synthesised in the presence of pluronic F68 by the chemical route exhibited synergism in antibacterial activity as compared with those synthesised without pluronic F68. On the contrary, biogenic silver nanoparticles without pluronic F68 showed higher antibacterial potential. [ABSTRACT FROM AUTHOR]

Effects of pretreatment and drying methods and particle size on characteristics of fibre powder from Centella asiatica L. leaves were investigated. Thermal stability of oil-based colour solutions was also assessed. Steaming and combined steaming and alkaline soaking resulted in the powder with more greenness and higher chlorophylls contents, while combined steaming and acid soaking yielded dark yellow powder with lower chlorophylls contents. Chemical soaking led to the powder with decreased water holding capacity and solubility. Vacuum-drying reduced chlorophylls degradation, hence retention of the greenness of the powder. Increased particle size resulted in decreased lightness of the powder, but in increased lightness of the solutions; water and oil holding capacities of the powder increased with the particle size. Fourier transform infrared (FTIR) spectra and X-ray diffraction ( XRD) patterns of the powder corresponded to its colour and functional property changes. Colour of the solutions changed only slightly upon heating at 80 and 180 °C for 1 h. [ABSTRACT FROM AUTHOR]

In this study, degradation of 2-nitrophenol (2NP) by UV/NiFe2O4 supported on Clinoptilolite (UV/NiFe2O4/CP) was investigated in a batch photo reactor. The prepared catalyst was characterized by X-ray diffraction pattern and scanning electronic microscopes and the effect of different variables such as initial pH, catalyst concentration and initial dosage of pollutant on the rate of reaction has been examined. In optimum conditions (1 g/L of catalyst, pH at 6 and initial concentration of 2NP at 20 mg/L), 95.3% of the pollutant degraded and 71% of COD removed in 180 and 240 min, respectively. The rate of degradation represented by the mechanism of Langmuir-Hinshelwood was found to follow pseudo first-order kinetics with =1.69×10-min-1 The degradation and mineralization of 2NP were confirmed by HPLC and COD tests. [ABSTRACT FROM AUTHOR]

The correlation between structural and electrical properties of cadmium titanate (CdTiO3) ceramic was established through X-ray diffraction combined with electrical and optical characterization techniques. The compound was prepared using a hightemperature solid-state reaction technique. Preliminary study on some structural aspect of the material using X-ray diffraction pattern showed the formation of singlephase compound in orthorhombic crystal system. Some characteristics of molecular structure of the material were studied by using Fourier transform infrared spectroscopy and ultraviolet visible spectroscopy techniques. The size and distribution of grains in the scanning electron micrograph revealed the polycrystalline nature of the material with size anisotropy and small number of voids. Detailed analysis of temperature-frequency dependence of dielectric parameters (i.e. dielectric constant and tangent loss) has revealed many interesting and important results of the material. The impedance studies of CdTiO3 over a wide range of temperature and frequency in the complex plane formalism with suitable equivalent circuit have shown some correlation between microstructure and electrical properties of the material. From the impedance and dielectric measurements some electrical parameters such as bulk resistance, capacitance, relaxation time and relative dielectric constant were calculated. The variation of DC conductivity with inverse of absolute temperature follows the Arrhenius relation. The study of frequency dependence of AC conductivity suggests that the material obeys Jonscher's universal power law. [ABSTRACT FROM AUTHOR]