Search

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

This work studies the influence of the properties of nanocrystalline -titanium dioxide (ncTiO2) films on the performance of solar cells based on the Organic materials/ncTiO2 multilayer structure. That was investigated using X-ray diffraction, Atomic force microscopy (AFM), and Source-Measure Unit(SMU) under different ambient conditions. The device produced from batch A exhibit better performance compared to the device produced from batch B. The short circuit current, Jsc, increases from 0.03 mA/cm² to 0.22 mA/cm², and the power conversion efficiency, η, from 0.01% to 0.09% in comparison between batches A and B solar cells. That is attributed to the grains of batch A nc-TiO2 having a size of 25 nm and a height of 100 nm, while particles of batch B nc-TiO2 film have a height of 40 nm and a size of 19 nm. These features cause to increase in the resistance and defects throughout the bulk region and interfaces of Batch B solar cells and impact the mechanism processes of charge generation of solar cells. [ABSTRACT FROM AUTHOR]

In order to obtain the effects of different amounts of metakaolin on the physical, mechanical properties and hydration characteristics of concrete, basic physical and mechanical tests of metakaolin concrete and concrete hydration performance tests were carried out. The results show that the proper addition of metakaolin instead of concrete cement admixture can better improve the mechanical properties and working performance of concrete. However, with the increasing content of metakaolin, the cement content inside the concrete will decrease and the chemically bound water inside the concrete will decrease. So that the heat and rate of hydration are reduced, and the content of calcium hydroxide generated by the hydration reaction is reduced. By combining the XRD pattern analysis of metakaolin after hydration, it can be known that the peak value of the XRD pattern of ettringite is the most significant when the content of metakaolin is 15%. This is consistent with the content of metakaolin that is obtained in the early stage to achieve the best mechanical properties of concrete.

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

In this work, Nickel-Cobalt-Phosphorous (Ni-Co-P) ternary coating has been deposited by electroless technique on copper substrate from an acidic electroless coating bath. The effects of heat treatment on surface roughness, surface morphology, crystal orientation and effect on hardness for electroless Ni-Co-P coating have been studied. The as-deposited Ni-Co-P alloy with high Phosphorous content shows initiation of crystalline structure. For the coated samples, structural changes have been observed after heat treatment. The precipitation of the Ni3P phase has been observed after heat treatment at 400°C. Further increase in annealing temperature resulted in the formation of CoP and Ni2P phases. The hardness of the electroless Ni-Co-P coating has been found to reach its maximum at 400°C annealing temperature due to the precipitation of Ni3P phase. Annealing at 400°C caused a significant increase of the hardness of as-deposited coating from 701.3 VHN to 1154.6 VHN. [ABSTRACT FROM AUTHOR]

The goal of this paper was to evaluate the influence of a range of plasma generation voltages on the physicochemical, structural, and technological properties of Aria (Goeppertia allouia) starch. Untreated (0 kV) and high voltages of cold plasma generation (7, 10, 14, and 20 kV) treated samples were evaluated according to their amylose content, pH, groups carbonyl/carboxyl, molecular size distribution, structure and technological properties (empirical viscosity, hydration properties, thermal analysis and gel strength). The applied voltage of 14 kV resulted in the greatest depolymerization of the starch chains, while 20 kV allowed the formation of oxidized complexes, promoting crosslinking of the starches chain. The cold plasma technique did not affect the levels of resistant starches, but increased the starch digestibility. The increased carbonyl and carboxyl groups also influenced the paste viscosity, improved hydration properties. This study suggests that the cold plasma technique can be useful in the controlled modification of starches, producing starches with different technological properties. • Dielectric barrier plasma modifies physicochemical properties of aria starches. • Different plasma generation voltages were applied: 7, 10, 14, and 20 kV. • 14 kV showed greater reduction in amylose content. • Aria starch presented phase transition from type-A to type-B crystal with cold plasma. [ABSTRACT FROM AUTHOR]

Spinel ferrite nanoparticles have astounding uses in the diverse field of applications. The virgin nickel ferrite (NiFe2O4), and cadmium (Cd) and strontium (Sr) substituted nickel ferrite nanostructures were synthesized by a self-ignited auto-combustion method. Such ferrites were characterized at room temperature to determine their composition dependent structural and magnetic properties. XRD patterns revealed cubic spinel single phase. Raman spectra disclosed five active phonon modes assigned to the spinel phase. FTIR spectra of the proposed nanoferrites exhibited two prominent absorption bands allotted to the stretching vibrations of tetrahedral and octahedral complexes. FESEM images manifested the evolution of porous NiFe2O4 microstructures. Magnetic properties of these ferrites were determined in terms of saturation magnetization, magnetic moment and Y–K angles. The small ratios of remanent to saturation magnetization clearly demonstrated the existence of multi-domains in the grown nanoferrites. The observed enhanced magnetic performance was endorsed to the A-site substitution in the spinel structure.

This Letter reports the synthesis of nanoceramic composite ZnAl2O4TiO2 by using a cost‐effective and straight forward sol–gel route. X‐ray diffraction (XRD) showed the ZnAl2O4 cubic structure along with the mixed anatase‐ and rutile‐phases of TiO2. Rietveld refinement is performed using XRD pattern to study the structural parameters. Raman investigation endorsed the corresponding vibration peaks of TiO2 and ZnO. Field‐emission scanning electron microscopy evidenced the agglomerated spherical nanoparticles. Energy‐dispersive spectroscopy analysis demonstrated the elementary peaks of Zn, Al, and Ti at 4.5, 1.5, and 1 eV, respectively. LCR measurement revealed the decreased dielectric permittivity with the rise in frequency and temperature. This dielectric characteristic is attributed to the dipole movement of the charge carriers. Furthermore, the authors present the investigation of the conductivity and impedance of the prepared dielectric ceramic material. [ABSTRACT FROM AUTHOR]

Holmium (Ho3+)‐doped TiO2 solid laser active materials with different concentrations (1, 3, 5, and 7 wt%) of Ho3+ ions were prepared using a sol–gel method. A structural study of the samples using X‐ray diffraction (XRD) revealed the anatase phase of pure and doped TiO2 calcined at 500°C, which is confirmed by (101), (004), (200), (105), (211), (204), (116), (220) and (215) diffraction peaks. XRD analysis showen a deformation along the c‐axis of the anatase lattice constant with doping, and a random change in the grain size of the doped titania with respect to pure samples. The presence of the titania bonds (Ti–O–Ti) and (Ti–O) of pure and Ho3+‐doped samples were confirmed from the FTIR spectroscopy study of the samples. In addition, it was noted that bands around 1338, and 1339 cm−1 belonging to 3, 5, and 7 wt% dopant concentrations, while no band for 1 wt% was observed. UV‐Vis spectrophotometer and spectrofluorophotometer techniques were used to study the optical and spectroscopic characterizations of these samples. It was found that various fluorescence peaks for Ho3+ ions were observed in the UV–vis region under different pump wavelengths. This is a good indication of suitability of the material to be employed as a laser active medium. [ABSTRACT FROM AUTHOR]

NiO:ZnO nanocomposite is examined using a cost-effective gel method. X-ray pattern synthesis demonstrates that the prepared NiO:ZnO nanocomposites have a high crystallization with an average size of a 50 nm crystalline bead. SEM images reveal the morphology and particle size distribution of the NiO:ZnO Nano compound, and the average nanoparticle size was about 70 nm. The results showed that antibacterial studies against positive germs (G + Ve) for S. aureus and negative Gram (G-Ve) bacteria from E-Coli for concentration (50, 75 and 100 g/ml). The results showed that the antibacterial activity of NiO:ZnO nanocomposite against S. aureus bacteria was higher than that of E. coli. [ABSTRACT FROM AUTHOR]

A new uranyl Schiff base complex, [UO2(L)(DMF)] where L= 2, 2'-((1E, 1E')-(1, 2 phenylen bis (azanylylidene)) bis (methanylylidene)) bis (4-bromo phenol) by reaction between of H2L and (CH3COO)2UO2·2H2O was successfully synthesized. The complex characterized by FT-IR, 1H NMR as well as electronic and luminescence property measurements. This complex was used as a novel precursor for preparing U3O8 nanopowder at low temperature (400 ËC) by decomposition method. The average crystallite size of the U3O8 nanopowder that has been synthesized is about 22. nm as determined by the Scherrer equation. According the results, we found that U3O8 could stop biofilm formation in S. aureus PTCC 1112 (0.632 mg/ml), M. luteus PTCC 1110 (0.633 mg/ml) and E. faecalis (0.633 mg/ml). Also, U3O8 repressed biofilm formation in M. luteus PTCC 1110 (0.625 mg/ml), E. faecalis (0.313 mg/ml) and C. albicans PTCC 5027 bacterias (1.27 mg/ml).

Abstract Different formulations of geopolymers were synthesized in acidic media (phosphoric acid) starting from three different raw metakaolin materials to identify compositions of interest. Four different property groups were highlighted based on the most favorable thermal and water resistance properties (while maintaining acceptable mechanical properties). The groups were related to the chemical composition, setting time and setting temperature of the synthesized geopolymers. Indeed, mechanical strength was determined by chemical composition, such as the aluminum content and the amount of water in each sample. The results showed that the sample with Si/Al ≥ 1 and Al/ P = 1 exhibited compressive stress to rupture values ranging between 66 and 120 MPa and was thermal resistant. Water resistance with a mechanical strength of 50 MPa was obtained for the samples with Al/ P = 1 or 4 and Si/Al ≤ 1. This work highlights the possibility of selecting a specific property associated with the mechanical performance for an acidic geopolymer. Highlights • Acid geopolymer with various properties were determined. • The Al/P and Si/Al ratios control the mechanical properties. • Thermal and water resistant materials depend on the quantity of aluminum. • Water content in materials control the mechanical properties. [ABSTRACT FROM AUTHOR]

Micro analysis of pigments, plaster layers and binding media using SEMEDX, XRD and FTIR within Elshinawy palace proved that blue pigment is cobalt blue, green pigment is malachite yellow pigment is goethite, and binding medium is animal glue. These paintings were carried out on a ground layer of gypsum with animal glue as binding medium, in addition to a portion of calcite added deliberately to increase brightness of gypsum. The protein materials of animal glue gave in alkaline medium and in presence of copper a blue violet or purple color called Birut Molecules. [ABSTRACT FROM AUTHOR]

Polymer blend films based on Polyvinyl alcohol (PVA) / Poly(vinylpyrrolidone) (PVP) doped with different concentration of cerium ions [(PVA/PVP)- x wt. % Ce 3+ ] ( x  = 3%, 5%, 10% and 15%) were prepared by the conventional solution casting technique. The characteristics of the prepared polymer composite films were studied using X-ray diffraction (XRD), FT-IR and UV–Vis. spectroscopy. The XRD patterns of the investigated samples revealed a clear reduction on the structural parameters such as crystallinity degree and cluster size D of the doped PVA/PVP blend films compared with the virgin one whereas there is no big difference in the d spacing of the product composite films. Significant changes in FT-IR spectra are observed which reveal an interactions between the cerium ions and PVA/PVP blends. The absorption spectra in the ultraviolet–visible region showed a wide red shift in the fundamental absorption edge of (PVA/PVP)- x wt. % Ce 3+ composites. The optical gap E g gradually decreased from 4.54 eV for the undoped PVA/PVP film to 3.10 eV by increasing Ce 3+ ions content. The optical dispersion parameters have been analyzed according to Wemple–Didomenico single oscillator model. The dispersion energy E d , the single oscillator energy E o , the average inter-band oscillator wavelength λ o and the static refractive index n o are strongly affected by cerium ions doping. Cerium ions incorporation in PVA/PVP blend films leads to a significant increase in the refractive index and decrease in the optical gap. These results are likely of great important in varieties of applications including polymer waveguides, organic semiconductors, polymer solar cells and optoelectronics devices. [ABSTRACT FROM AUTHOR]

The domain structure of 0.367 BiScO 3 - 0.633 PbTiO 3 piezoelectric ceramic is investigated from the view of different electrical poling. The X-ray-diffraction (XRD) approach is used to acquire relative intensity ratio of domain reflections, thus the domain switching fraction or domain texture that results from electrical poling is directly observed. Based on the XRD profiles, a diffraction-plane-transformation (DPT) model that can provide a visualized insight into domain switching in tetragonal perovskite phase is proposed. The intensity variation of diffraction reflections in XRD pattern is comprehensively explained by DPT model, meanwhile an alternative method is also proposed to estimate the domain switching fraction in comparison with previously reported method. The experimental results show that the proposed DPT model is a simple, rational and effective method, which is also of edificatory significance to other tetragonal perovskite piezoelectric ceramic. [ABSTRACT FROM AUTHOR]

The multiferroic BiFeO3 and Bi0.8A0.2Fe0.8Mn0.2O3 (A = Ca, Sr) have been synthesized using direct mechanosynthesis. Detailed investigations were made on the influence of Ca-Mn and Sr-Mn co-substitutions on the structure change, electric and magnetic properties of the BFO. Rietveld refinement on the XRD pattern of the modified samples clarifies the structural transition from R3c:H (parent BiFeO3) to the biphasic structure (R3c: H + Pnma). Scanning electron micrographs confirmed the polycrystalline nature of the materials and each of the microstructure comprised of uniformly distributed grains with less porosity. The dielectric measurements reveal that enhancement in dielectric properties due to the reduction of oxygen vacancies by substitutional ions. Studies of frequency-dependence of impedance and related parameters exhibit that the electrical properties of the materials are strongly dependent on temperature, and bear a good correlation with its microstructure. The bulk resistance (evaluated from impedance studies) is found to decrease with increasing temperature for all the samples. The alternating current (ac) conductivity spectra show a typical signature of an ionic conducting system, and are found to obey Jonscher’s universal power law. Preliminary studies of magnetic characteristics of the samples reveal enhanced magnetization for Ca-Mn co-substituted sample. The magnetoelectric coefficient as the function of applied dc magnetizing field under fixed ac magnetic field 15.368 Oe is measured and this ME coefficient αME corresponds to induction of polarization by a magnetic field. [ABSTRACT FROM AUTHOR]

Numerous industrial processes are based on the application of phenolic compounds such as Bisphenol-A (BPA), which is used as a monomer and additive in plastics, resins, and coatings manufacturing. Many phenolic compounds are highly toxic and responsible for high pollution in food, water, and soil. The endocrine disrupting activities of BPA makes it an emerging environmental pollutant. The most common source of BPA release into the environment is from plastic packaging. This leakage from plastic packaging is facilitated by heat and pH conditions which speeds up the hydrolysis of the ester bonds. In this paper, we report the estimation of BPA concentration in ethanol, using nanostructured manganese dioxide as a receptor using a non-faradaic electrochemical impedance spectroscopy. An equivalent electrical circuit model has been proposed for electrochemical impedance data of BPA solutions in pure ethanol. A linear relationship of impedance response with the concentration over a range from 1 nM– 62.5~\mu \textM is observed. The detection limit is estimated around to be 0.66~\mu \textM . During the measurement, it has been taken care that the electrodes must give excellent reproducibility. [ABSTRACT FROM PUBLISHER]

Copyright of Journal of College of Education is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We proposed a novel ex-situ sol-gel synthesis of Nd3+ (0.7 mol%) and Yb3+ (X; X = 0.0, 0.7, 1.5, 3.0 mol%) ion co-doped Zinc-Silicate (SZNYX) dense glass-ceramic(DGC) samples. The structural analyses of the SZNY07-DGC sample were performed at different annealing temperatures using X-ray diffraction (XRD) analysis and Fourier transforms infrared (FTIR) spectroscopy. The tetragonal willemite Zn 2 SiO 4 structure with an R-3(148) space group was confirmed from XRD results. The formation of the pure oxide phases (bridging oxygen) was noticed at FTIR spectra with the complete removal of hydroxyl impurity at higher annealing temperatures. The presence of ZnO crystallites with the inter-planer spacing of ⁓ 0.28 nm and Nd3+/Yb3+ ion pair in an amorphous silica host was confirmed via transmission electron microscopy (TEM) and TEM-energy dispersive spectroscopy (EDS) respectively. The white up-conversion luminescence (UCL) under a 980 nm excitation was attributed to the simultaneous emission of wavelength in the visible spectrum. The intensity of UCL was initially rising with an increase in Yb3+ ion concentration whereas the optimized luminescence was obtained for samples with 1.5 mol% Yb3+ ion concentration. The CIE chromaticity coordinates (0.34, 0.35) of corresponding UCL spectra were invariant with the change in Yb3+ ion concentration. The photoluminescence (PL) confocal mapping of the SZNY15-DGC sample was performed at different locations under a 980 nm laser excitation source which turned out non-uniform in nature throughout the surface. Thus as-synthesized SZNYX-DGC samples have spectacular upconversion luminescence for near-infrared excitation which may be utilized in thermal sensing, photovoltaic, displays, and photonic devices. [ABSTRACT FROM AUTHOR]

Gadolinium aluminate (GdAlO _3 , GAP) nano whiskers were synthesized by the hydrothermal-solid state method, Fourier-transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) and thermogravimetry-differential thermal analysis (TG-DTA) were employed to analyze the phase change and the nucleation mechanism of GAP during calcing process. The results show that the precursor of GAP prepared by hydrothermal is (NH _4 ) _x GdAl(OH) _y (NO _3 ) _z ·nH2O. When the calcination temperature is higher than 900 °C, the precursor recrystallizes, forming the needle shape GAP under the synergistic effect factors. The best preparation conditions are as follows: ammonia water as mineralizer, pH = 9, calcination temperature 1100 °C and holding time 3 h.

Abstract We report the electrical and optical studies of thin films of a-GaxSe100−x nanorods (x = 3, 6, 9 and 12). Thin films of a-GaxSe100−x nanorods have been synthesized thermal evaporation technique. DC electrical conductivity of deposited thin films of a-GaxSe100−x nanorods is measured as a function of temperature range from 298 to 383 K. An exponential increase in the dc conductivity is observed with the increase in temperature, suggesting thereby a semiconducting behavior. The estimated value of activation energy decreases on incorporation of dopant (Ga) content in the Se system. The calculated value of pre-exponential factor (σ0) is of the order of 101 Ω−1 cm−1, which suggests that the conduction takes place in the band tails of localized states. It is suggested that the conduction is due to thermally assisted tunneling of the carriers in the localized states near the band edges. On the basis of the optical absorption measurements, an indirect optical band gap is observed in this system, and the value of optical band gap decreases on increasing Ga concentration.

In this study, cupric oxide (CuO) nanoparticles were prepared using sonochemical method. The prepared nanoparticles were studied using X‐ray diffraction (XRD) pattern, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) methods. The colloidal chitosan (CS) solution was prepared using ultrasound irradiation method and simultaneously mixed with CuO nanoparticles. The coatings of colloidal solution with and without CuO nanoparticles were studied through TEM images. The cotton fabrics were separately soaked in the prepared nanoparticle‐containing (hybrid) solutions by sonication method followed by pad‐dry‐cure method. The structural, functional, and morphological analyses of the coated and uncoated fabrics were performed using XRD, FTIR‐attenuated total reflectance, and SEM analyses, respectively. The hybrid‐coated cotton fabrics showed better antibacterial activity against Staphylococcus aureus and Escherichia coli. The bioactivity performance of the coated fabrics was in the order of CuO‐coated fabric > CS‐coated fabric. [ABSTRACT FROM AUTHOR]

A method of studying the phase composition of compact ceramics based on titanium nitride is described and the results of the X-ray diffraction analysis of the material obtained are presented. It is shown that, in the process of nitridation, the phase composition of the surface of the specimen changes and every step of the process is characterized by an individual and definite set of phase states. [ABSTRACT FROM AUTHOR]

Nanostructured CoCu granular alloys have been prepared by borohydride reduction of CuCl 2 and CoCl 2 salt solutions using cetyltrimethylammonium bromide (CTAB) as a surfactant. Characterization by inductively coupled plasma optical emission spectroscopy (ICPOES), X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies yields spherical particles of Co x Cu 1− x ( x ∼ 0.01 – 0.3 ) of average size 8–25 nm formed in a face-centered-cubic ( fcc ) lattice as in copper. Studies of zero-field-cooled/field-cooled (ZFC/FC) magnetization and thermoremanent magnetization (TRM) have been performed in the temperature range 4–300 K, and the results have been analyzed by independent particle model. At the lowest cobalt concentration ( x ∼ 0.01 ), the alloy is superparamagnetic and there is no blocking of magnetization down to 4 K. For all other samples, the magnetization at low magnetic field is characterized by a blocking temperature distribution which is not influenced by the Co content in samples. Study of hysteresis loops shows that the magnetization at any temperature 4–300 K is a sum of ferromagnetic (FM), superparamagnetic (SPM) and paramagnetic (PM) contributions. The FM part increases and SPM part decreases with increase in Co content. However, the values of coercivity and magnetic anisotropy constant do not depend on Co content. The results suggest that Co x Cu 1− x alloys are formed in a spherical core-shell type structure with cobalt being concentrated near the core of particles. [ABSTRACT FROM AUTHOR]

• Simulation via molecular dynamics of mechanical properties in (U,Pu)O2 as a function of irradiation dose. • Calculation of simulated XRD patterns as a function of irradiation dose. • Correlation between XRD patterns and microstructural evolution as a function of irradiation dose including swelling. [Display omitted] Molecular dynamics simulations of microstructural evolution under irradiation of (U,Pu)O 2 solid solutions have been carried out with the Frenkel pair accumulation method with two empirical potentials. Simulated X-Ray diffraction patterns have been systematically generated along the irradiation pathway from the computed atomistic configurations. Description of the X-Ray diffraction patterns for each of these well characterized damage microstructure snapshots is discussed. Attempt to correlate the features of the X-Ray diffraction peaks with the microstructural evolution with irradiation dose is also provided. Special attention is dedicated to the swelling effect. [ABSTRACT FROM AUTHOR]

The present paper reports the thermoluminescence (TL) glow curve of Eu-activated SrAlO phosphor with different UV exposure times. Evaluation of kinetic parameters was done by the peak shape method. The recorded glow curve shifts towards lower temperatures with respect to increasing UV exposure time. The peaks were found at 146.76, 141.34 and 140.37 °C, respectively, for 5, 10 and 15 min of UV exposure using the heating rate of 3°C s. The glow peak shows the second-order kinetics. Different kinetic parameters, i.e. trap depth, order of kinetics, activation energy, and frequency factor are also calculated. The XRD pattern of the sample is compared with reported XRD using the software match. [ABSTRACT FROM AUTHOR]

Highlights: [•] Important report on simplified spray deposited In-doped ZnO films. [•] PL, electrical and structural results are corroborated with each other. [•] Enhancement of electrical parameters by means of indium-doping. [•] Smooth nanostructures are grown along c-axis. [•] The linear dependence of physical properties on the substrate temperature of as-grown films is confirmed. [ABSTRACT FROM AUTHOR]

In this study, facile and ecofriendly methods have been developed for the biosynthesis of silver nanoparticles from silver nitrate using the seed extract of Strychnos potatorum, a natural phytocoagulant. The effect of room temperature stirring, water bath heating and autoclaving on nanoparticle synthesis was studied. The water soluble compounds in the extract serve as reducing and stabilising agents. Analytical techniques such as UV–visible spectroscopy, transmission electron microscopy (TEM) and X‐ray diffraction were used to characterise the synthesised nanoparticles. By tuning the reaction conditions, size controlled spherical nanoparticles of around 14.1 ± 4.8 nm were generated. The face centred cubic crystalline structure of the nanoparticles is confirmed from the observed peaks corresponding to (111), (200), (220) and (311) planes in the XRD pattern, concentric rings with intermittent bright dots in selected‐area electron diffraction patterns and clear lattice fringes in high‐resolution TEM images. With Fourier transform infrared spectroscopy and Raman spectroscopy, a probable mechanism involved in the reduction and stabilisation of nanoparticles has been investigated. As the silver nanoparticles are encapsulated with functional groups, they can be easily integrated for various biomedical applications. [ABSTRACT FROM AUTHOR]

The biological approach to synthesize metal nanoparticles is an important aspect of current nanotechnology research. Silver nanoparticles have been well-known for their inhibitory and antimicrobial effects. The ever-increasing antibiotic resistance in pathogenic and opportunistic microorganisms is a major threat to the health care industry. In the present investigation, silver nanoparticles have been successfully biosynthesized by Streptomyces sp JAR1. Biosynthesized silver nanoparticles were characterized by means of several analytical techniques including a UV-Visible spectrophotometer, Fourier transform infrared spectroscopy, X-ray diffraction pattern analysis, and atomic force microscopy. An evaluation of the antimicrobial activity of silver nanoparticles (AgNPs) was carried out against clinically important pathogenic microorganisms. The metal nanoparticles were also evaluated for their combined effects with antibiotics against the clinical pathogens. The anti- bacterial activities of the antibiotics increased in the presence of the biologically synthesized AgNPs against the clinically important pathogens. The highest enhancing effect was observed for erythromycin against the test pathogens. [ABSTRACT FROM AUTHOR]

Two aluminate spinel materials (ZnAlO and NiAlO) were synthesized by the citrate precursor method. The citrate precursors consisting of coprecipitated citrates of Zn or Ni and aluminum were first subjected to thermal analysis (TG-DSC) for determining the optimum temperature for annealing. Two step decomposition was observed incorporating dehydration and formation of the aluminate. The second step gives an endo peak (−2937 J/g) at 356 °C in the DSC curve of the coprecipitated nickel(II) citrate-aluminum citrate gel in O atmosphere. Kinetic/mechanistic analysis of the TG data has also been carried out and values of E, Δ S, Δ G, and A were approximated. On the basis of the findings, 450 °C has been chosen for annealing of the gels. Annealing has also been done at 650 °C for 1 h in muffle furnace in an attempt to obtain nanometric particles of aluminates (MAlO) {M = Ni, Zn} and to find out their magnetic properties which could render them useful for chemical sensing applications, etc. The TG-DSC curves of various powders which were obtained on annealing at the two temperatures did exhibit thermal instability when carried out in N atmosphere. NiAlO and ZnAlO spinels (particle size 17 and 34 nm, respectively) are obtained in pure crystalline phase at 650 °C. ZnAlO prepared this way shows coercivity values of 470 and 58.37 G and NiAlO, 107 and 23.24 G when annealed at 450 and 650 °C, respectively. ZnAlO prepared by a polymer precursor method and annealed at 1000 °C, has earlier been reported to have coercivity value of 469 G. Thus, the citrate precursor method is good for the synthesis of ZnAlO, producing single phase nanocrystalline powder of high quality and crystallinity. The value of magnetization was found to be small in the present case for the NiAlO spinel obtained at 450 °C. [ABSTRACT FROM AUTHOR]

Abstract: ZnAl layered double hydroxides (LDHs) with nitrate as the charge balancing anion in the interlayer space were synthesized by precipitation from homogeneous solution using urea hydrolysis. The composition of the synthesis mixture and the synthesis time were varied in order to identify the parameters, which control if nitrate or carbonate will be the interlayer anion. Especially, the addition of ammonium nitrate turned out to be an effective tool for the synthesis of nitrate containing ZnAl LDHs independent from the synthesis time. Results are mainly based on powder X-ray diffraction measurements of the obtained samples. [Copyright &y& Elsevier]

Abstract: Aluminium nitride (AlN) reactively sputter-deposited from an aluminium target is an interesting piezoelectric thin film material with high CMOS compatibility. A good c-axis orientation is essential for obtaining high piezoelectric coefficients. Therefore, the influence of different sputtering conditions on the microstructure of AlN thin films with a typical thickness of about 500nm was investigated. In this study it is demonstrated that highly c-axis oriented AlN thin films can be deposited on nominally unheated (100) silicon substrates, most preferentially when using a pure nitrogen atmosphere. The degree of c-axis orientation increases with higher nitrogen concentration and with decreasing the sputtering pressure, whereas the influence of plasma power on the microstructure was found to be negligible. A low sputtering pressure is also useful for minimizing the amount of oxygen contaminations in the deposition chamber and hence for reducing the incorporation of impurities into the AlN films. Intrinsic stress values of AlN thin films were determined by wafer bow measurements and were found to be between −3.5 and 750MPa depending on choice of deposition parameters. Finally, the piezoelectric coefficients d 33 and d 31 were determined experimentally by laser scanning vibrometry in conjunction with a theoretical model. Effective values in c-axis oriented 500nm films with FWHM of 0.33° are 3.0 and −1.0pm/V. For a film of 2.4μm thickness, values of 5.0 and −1.8pm/V were measured, which are near the bulk values. [Copyright &y& Elsevier]

We report the electrical and optical studies of thin films of a-Ga xSe100− x nanorods ( x = 3, 6, 9 and 12). Thin films of a-Ga xSe100− x nanorods have been synthesized thermal evaporation technique. DC electrical conductivity of deposited thin films of a-Ga xSe100− x nanorods is measured as a function of temperature range from 298 to 383 K. An exponential increase in the dc conductivity is observed with the increase in temperature, suggesting thereby a semiconducting behavior. The estimated value of activation energy decreases on incorporation of dopant (Ga) content in the Se system. The calculated value of pre-exponential factor (σ0) is of the order of 101 Ω−1 cm−1, which suggests that the conduction takes place in the band tails of localized states. It is suggested that the conduction is due to thermally assisted tunneling of the carriers in the localized states near the band edges. On the basis of the optical absorption measurements, an indirect optical band gap is observed in this system, and the value of optical band gap decreases on increasing Ga concentration. [ABSTRACT FROM AUTHOR]

Starch from Moth bean (Phaseolus acontifolius Jacq) was isolated and some of the important characteristic determined. The yield of starch was 38.8% w/w of a whole raw seed basis. The shape of the starch granule was oval to round shaped, with granules 9-59 μm in diameter. Scanning electron micrograph revealed the presence of smooth surfaces. TGA thermogram value revealed that moth bean starch possesses The gelatinization temperature range was 72-78-82°C .The X-ray diffraction pattern was of the 'C' type and the intensity of X-ray was much stronger than in tuber starches. The Relative viscoamylograph examination of the starch paste showed high paste viscosity as compared to Potato starch. [ABSTRACT FROM AUTHOR]

Abstract: FePt alloy in a bulk state is well known as a magnetic material. FePt nanoparticles, which are protected by poly(N-vinyl-2-pyrrolidone) (PVP) and have a face-centered tetragonal (fct) structure at a size of a few nanometers in diameter, have been directly synthesized by a polyol process in high-boiling point tetraethylene glycol used as a reducing reagent for the reduction of Fe(III) acetylacetonate and Pt(II) acetylacetonate. Their magnetic properties (coercivity and saturation magnetization) were dependent on the size and made progress as their diameters increased. The size in diameter was easily controlled by altering the content of PVP, the time for refluxing, and reaction temperature. FePt nanoparticles showed diameter-dependent coercivities at room temperature and they abruptly increased at over 4nm in diameter. Ferromagnetic FePt nanoparticles with an fct structure were also synthesized at relatively low reaction temperature without refluxing. Likewise, as-synthesized FePt nanoparticles prepared by refluxing at 251°C for 3h displayed the fct structure and clearly indicated the ferromagnetism at room temperature. Reaction kinetics such as long refluxing time and slow temperature elevation rate were found to be important key factors to synthesize the ferromagnetic FePt nanoparticles although the reaction temperature was very critical as well. [Copyright &y& Elsevier]

ZnO thin films are used for a number of MEMS-based sensors because of the piezoelectric and semiconducting properties. In certain class of devices, especially those using surface acoustic wave (SAW) technology on a layered substrate (such as ZnO on Si), it is a requirement to grow several micron thick ZnO layer which must be highly c axis oriented. In this attempt, we have deposited ZnO films by sol-gel spin process and using three different concentrations of 10%, 12.5%, and 25% of sol using zinc acetate as the precursor material and characterized for their thickness and other associated characteristics. The XRD pattern showed diffraction peaks of the hexagonal ZnO phase. The intensity of the 002 peak was much low for low-strength sols indicating substantial preferred orientation of the crystallites perpendicular to the sample surface. The crystallite size was estimated to be about 45 nm from the 100 diffraction peak. For the sample with 25% strength of the sol, the XRD pattern showed diffraction peaks of the hexagonal ZnO phase. The crystallite size was estimated as about 60 nm from the 100 peak and about 145 nm from the 002 peak. The TEM results showed fine nanoparticles with hexagonal ZnO crystal structure and morphology dependence upon the sol strength. Faceted morphology of hexagonal ZnO nanostructures has been obtained. The results would find application in nanoelectronic piezoelectric sensors. [ABSTRACT FROM PUBLISHER]

Pt50–Fe50 nanoparticles were synthesized by the chemically wet process for developing a new high efficiency cathode catalyst in PEFCs. The particle morphology and crystal structure of as synthesized Pt–Fe particles, and electronic state of Fe atoms in them were evaluated using transmission electron microscopy(TEM), X-ray diffraction(XRD) and transmission Mössbauer spectroscopy (TMS), respectively. They are confirmed to be of chemically disordered fcc structure from XRD pattern and the average diameter of them was estimated to be 3.1 nm from both TEM and the width of (111) peak in XRD pattern. From TMS spectrum, it was concluded to consist of mainly the component of Fe oxides connected with the organic ligands according to XPS results mentioned below. But, probably it contains the component for superparamagnetic Pt–Fe nanoparticles. Also the electrocatalytic activity and a hydrogen adsorption/desorption behavior for as synthesized Pt–Fe nanoparticles was observed by cyclic voltammetry and the oxidation of Fe atoms in as synthesized Pt–Fe nanoparticles, Fe metal and Fe oxides were measured. [ABSTRACT FROM AUTHOR]

Abstract: Direct synthesis of fct-structured FePt nanoparticles was successfully achieved by using poly(N-vinyl-2-pyrrolidone) as a protective reagent at lower temperature than the case using low molecular weight ligands as a protective reagent. Experimental data suggest that a transformation of FePt nanoparticles from face-centered cubic to face-centered tetragonal (fct) structure takes place at reaction temperature of 261 °C. The results of XRD and the magnetic properties exhibit that the FePt nanoparticles synthesized at 261 °C have partially ordered fct-structure and a ferromagnetic behavior at room temperature. [Copyright &y& Elsevier]

Abstract: Cobalt containing hexagonal mesoporous molecular sieves (MCM-41) were prepared by different methods viz., direct hydrothermal synthesis, grafting and immobilization. The calcined material was characterized by various spectroscopic tools such as powder X-ray diffraction (XRD), N2 adsorption–desorption isotherms, Fourier transformed infra-red (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance UV–vis and X-ray photoelectron spectroscopy (XPS). The XRD patterns show the highly intense (100) reflection peak in the range 2–3° (2θ angle), characteristic of mesoporous material. Higher order reflection peaks suggest highly ordered mesoporous structure. N2 adsorption–desorption isotherms are of type IV according to IUPAC classification and the steep rise in the isotherms in the narrow range 3.5–4.5 of relative pressure (P/P 0) is due to the condensation of N2 gas molecules in the pores (characteristic of mesoporous structure). In FT-IR increase in the intensity of band at 960cm−1 with the increase of the cobalt content in Co-MCM-41 samples indicate the incorporation of cobalt ions in the framework of MCM-41. SEM and TEM reveal spherical morphology for the cobalt substituted MCM-41. UV–vis spectra demonstrate the characteristic features of framework and extraframework cobalt in MCM-41. Cobalt is in +2 oxidation state as evidenced from UV–vis and XPS. The catalysts were tested for the side chain oxidation of ethylbenzene using 70wt.% tert-butyl hydrogen peroxide as an oxidant with and without the use of solvent. Solvents have effect in the catalytic activity and selectivity. In the absence of solvent, substituted cobalt [Co-MCM-41 (50)] in the framework of MCM-41 gives maximum ethylbenzene conversion while higher selectivity to acetophenone was achieved over immobilized cobalt on the MCM-41. Leaching data shows, immobilized cobalt catalyst is well hetrogenized. [Copyright &y& Elsevier]

Polycrystalline PbZr0.52Ti0.48O3 (PZT) thin films with different thicknesses were prepared by metal-organic decomposition (MOD) at different thermal decomposition temperatures, and their effective elastic constants were evaluated with X-ray diffraction (XRD) techniques. The relative intensities of textures in the thin films were analyzed from XRD patterns, and the effective elastic constants were calculated by averaging over orientations according to the relative intensities. On the other hand, Gaussian distribution functions were used to fit the normalized intensities of (001) pole figures, and the effective elastic constants of PZT thin films were calculated according to the grains’ orientation distribution described by Gaussian distribution functions. The results show that the effective elastic constants of PZT polycrystalline thin films evaluated by XRD patterns are in good agreement with those evaluated by pole figures, and the differences are within 10%. The effective elastic constants of PZT thin films are greatly affected by the thermal decomposition temperature, while the effects of thickness of thin films are relatively small. [ABSTRACT FROM AUTHOR]