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The Internet of things (IoT) is gaining popularity due to diverse applications and market potential. They are pushed more into remote locations and developers look for a perpetual power source. The vibration energy harvester (EH) is capable to mitigate powering issues. Zinc oxide (ZnO), Polydimethylsiloxane (PDMS) and Silver (Ag) were used. However, it is observed that film grains size has a great impact i.e. large-grained films are superior to small-grained films. This work analyses impacting parameters and relevant empirical study. Scanning-Electron-Microscope (SEM), X-ray Diffraction (XRD), Electrical characterization were carried out for in-depth analysis. It is observed that 46.92 µWpeak/15.03 µWrms power is achieved in this work. [ABSTRACT FROM AUTHOR]

Organic single crystal of p-Toluidinium l -Tartrate (PTLT) was grown from aqueous solution by slow evaporation technique. X-ray diffraction analysis confirmed the crystal structure and high resolution XRD showed the crystalline perfection of the grown crystal. UV–vis spectral analysis revealed the cut-off wavelength at deep UV region and band gap energy of the grown crystal. The second order nonlinear optical properties of the grown crystal were ascertained by Kurtz-Perry powder technique. The laser damage threshold value of PTLT (2.0 GW/cm2) was estimated and it is relatively higher than that of Ammonium hydrogen l -Tartrate single crystal (0.53 GW/cm2). The optical studies demonstrated that the PTLT crystal could be a potential organic NLO material for frequency doubling applications. [ABSTRACT FROM AUTHOR]

This paper presents the experimental study on the thermophysical behavior, thermal cyclic characteristics and energy storage performance of liquid metal (LM) laden in organic solid-liquid phase change material (PCM) for energy storage. In this view, Gallium (Ga) is added into D-Mannitol (DM) with a weight fraction of 0.1% and 0.5% by dispersion technique using a ball mill. Repeated melting/freezing cycle was carried out for 350 cycles and the samples were characterized using Differential Scanning Calorimetry (DSC), Thermogravimetry Analysis (TGA) and Fourier Transform Infrared (FTIR). The DM/Ga composite PCM showed enhanced thermal conductivity of ∼8.4%, ∼27.8% for 0.1 and 0.5 wt % Ga as compared to pure DM. XRD studies reveal that the pure DM exhibited β polymorphic phase while TGA and FTIR analysis confirm the thermal reliability and chemical stability of composites in the temperature range of 50–200 °C. Non isothermal crystal kinetic study proved that the addition of Ga increased the crystallization rate due to heterogeneous nucleation effect and leads to the reduction in subcooling temperature of the PCM. The experimental setup results to test the charging and discharging performance of the composite PCM revealed that the total time for one complete cycle reduced from 97.48 min for pure DM to 84.73 min and 63.92 min for DM-Ga composite with 0.1 wt % and 0.5 wt % respectively. Based on the results obtained, D-Mannitol based composites could be recommended as potential PCM candidates for solar heat and industrial waste heat recovery application due to its high energy density capacity, thermal/chemical stability and good heat transfer performance. [ABSTRACT FROM AUTHOR]

Glasses of composition PbO–Nb 2 O 5 –GeO 2 –SiO 2 doped with different concentrations of Cr 2 O 3 (ranging from 0 to 0.5 mol%) were prepared by conventional melt quenching technique. The prepared glasses were characterized by X-ray diffraction (XRD). Spectroscopic studies viz., optical absorption, EPR, FTIR, Raman and photoluminescence were carried out on these glasses. The optical absorption spectra exhibited three bands at about 646, 674 and 711 nm which are the characteristic bands of octahedral Cr 3+ ions. From the analysis of the absorption spectra the crystal field splitting parameters D q , B and nephelauxetic parameters (β and h ) were evaluated. The EPR spectra exhibited two resonance signals at g≈1.97 and g≈4.84. FTIR and Raman spectra have revealed the increasing presence of GeO 6 and NbO 6 structural units in the glass network with increasing the concentration of Cr 2 O 3 in the glass network. Photoluminescence spectra exhibited a broad emission band in the wavelength region 600 to 850 nm with a meta center at about 680 nm which is also a characteristic of Cr 3+ ions. Correlating optical and EPR data the molecular bonding coefficient parameter (α) has been evaluated. The quantitave correlation and analysis of all the results indicated that the glasses doped with higher content of Cr 2 O 3 are efficient luminescence materials. [ABSTRACT FROM AUTHOR]

This work focussed on the optical, magnetic and photocatalytic properties of sol-gel-synthesized FeO-doped ZnO nanospheres and was compared with pristine ZnO nanospheres. The crystalline phase of FeO-doped ZnO nanospheres was studied with X-ray diffraction analysis and was well matched with standard pattern. Surface morphology was studied with HR-SEM images and EDAX spectrum. Furthermore, elemental mapping analysis was carried out to confirm the presence of FeO phase in FeO-doped ZnO nanospheres. FT-Raman spectral studies show that a strong intense peak at 670 cm indicates the presence of FeO in FeO-doped ZnO nanospheres. The mean crystallite size of FeO-doped ZnO nanospheres was 34 nm as calculated by Debye-Scherrer's formula which confirmed with HR-TEM image. The SAED pattern shows the presence of (100), (101), (102) and (202) of ZnO phase and (400) of FeO phase, confirming the crystalline nature of FeO-doped ZnO nanospheres. The vibrating sample magnetometer (VSM) result shows that FeO-doped ZnO nanospheres possess superparamagnetic nature and the composite nanospheres are magnetically separable. The optical properties have been studied by diffuse reflectance spectroscopy and time-resolved photoluminescence spectra. Implantation of FeO in ZnO nanospheres modifies the UV absorption edge, and it displays near-band gap emission and deep-level emission. The photocatalytic activity of FeO-doped ZnO nanospheres studied against rhodamine B dye is found higher than that of pristine ZnO nanospheres which shows that FeO-doped ZnO nanospheres are a promising photocatalyst. [ABSTRACT FROM AUTHOR]

The interaction of metal oxide nanoparticles with plants has not been extensively studied. An attempt has been made to examine the potential variation in peanut plant leaves due to the application of Fe 2 O 3 nanoparticle by pre-sowing technique and to compare with its bulk counterpart. Fe 2 O 3 nanoparticle was synthesized by chemical route and characterized using X-ray diffraction, atomic force and scanning electron microscopy. The Fe 2 O 3 nanoparticle and its bulk counterpart are applied to the peanut seeds by pre-soaking method at two different concentrations: 500 and 4000 ppm. A total of three replicates were chosen for each morphological and physiological measurement (at an average of three plants per replica). The Fourier transform infrared spectral analysis shows the most prominent peaks at 2923 and 1636 cm −1 , and other peaks vary due to Fe 2 O 3 stress, which was confirmed by the calculated mean ratio of the peak intensities for various frequency regions. All leaf samples show considerable increase in glycoprotein, with 500 ppm bulk and 4000 ppm nano-Fe 2 O 3 samples exhibiting a maximum increase of 73.86% and 71.45%, respectively. The total amide I and II protein content of leaf sample soaked in 500 ppm bulk Fe 2 O 3 suspension decreased to a greater extent compared with other leaf samples. The leaf samples soaked in 500 ppm concentration of both bulk and nano-Fe 2 O 3 suspension exhibited lower lipid content with total band area of 76.97 ± 0.832 and 76.31 ± 0.468, respectively. The cumulative percentage of explained variance in secondary structure of protein of all leaf samples is 83.888% in which factor 1 accounts for 51.870% and factor 2 accounts for 32.018% of the total data variance. The principal component (PC) loadings plot for the spectral range 1600–1700 cm −1 clearly shows that the PC1 factor might establish the maximum variation of the secondary structure of protein in leaf samples. [ABSTRACT FROM AUTHOR]

Chemical bath deposition (CBD) technique was used for the synthesis of the Nickel Sulphide (NiS) thin films. The prepared NiS thin films were found to be polycrystalline and the crystals had hexagonal structure as revealed in the X-ray diffraction (XRD) analysis. The surface morphology of these films was studied by means of scanning electron microscopy (SEM). The optical properties of the NiS thin films were determined using UV-Visible absorption spectrum. The electrical studies were carried out at different frequencies and at different temperatures for the prepared NiS thin films. Further, electronic properties, such as valence electron plasma energy, average energy gap or Penn gap, Fermi energy and electronic polarizability of the NiS thin films were calculated. The AC electrical conductivity measurements revealed that the conduction depended on both the frequency and the temperature. Photoconductivity measurements were carried out to reveal the positive photoconductivity of the NiS thin films. [ABSTRACT FROM AUTHOR]

In this article a series of epoxy nanocomposites film were developed using amine functionalized (ZnO-APTES) core shell nanoparticles as the dispersed phase and a commercially available epoxy resin as the matrix phase. The functional group of the samples was characterized using FT-IR spectra. The most prominent peaks of epoxy resin were found in bare epoxy and in all the functionalized ZnO dispersed epoxy nanocomposites (ZnO-APTES-DGEBA). The XRD analysis of all the samples exhibits considerable shift in 2θ, intensity and d-spacing values but the best and optimum concentration is found to be 3% ZnO-APTES core shell nanoparticles loaded epoxy nanocomposites supported by FT-IR results. From TGA measurements, 100 wt% residue is obtained in bare ZnO nanoparticles whereas in ZnO core shell nanoparticles grafted DGEBA residue percentages are 37, 41, 45, 46 and 52% for 0, 1, 3, 5 and 7% ZnO-APTES-DGEBA respectively, which is confirmed with ICP-OES analysis. From antimicrobial activity test, it was notable that antimicrobial activity of 7% ZnO-APTES core shell nanoparticles loaded epoxy nanocomposite film has best inhibition zone effect against all pathogens under study. [ABSTRACT FROM AUTHOR]

The transparent glasses with composition 30PbO–10GeO 2 –(60−x)SiO 2 −xNb 2 O 5 (mol%) (0 ≤ x ≤ 2.5) are prepared by conventional melt quenching technique. The amorphous nature of the prepared glasses is characterized by XRD. The spectroscopic studies such as optical absorption, FTIR, Raman spectra were carried out at room temperature on these glasses. Besides this electrical properties, like dielectric constant ε ' , loss tan δ , ac conductivity σ a c etc., were also investigated over a moderately wide range of frequency (10 3 –10 6 Hz) and temperature (30–300 °C). The optical absorption spectrum of the prepared glasses has exhibited absorption bands around 325 nm and 340 nm and these are due to the triplet – singlet electronic transition of Ge 2+ state presents in the glass matrix as conversion of GeO 2 into GeO is much easier rather than SiO 2 . From FTIR spectra of as prepared glasses, it is noticed that the intensity of octahedral NbO 6 structural units is found to increase up to 2 mol% of Nb 2 O 5 there after it is observed to decrease. It is also supported by Raman shift of NbO 6 structural units observed around 650 and 930 cm −1 . The analysis of electrical studies is also revealed that the conductivity of prepared glasses is found to increase gradually up to 2 mol% of Nb 2 O 5 beyond this concentration it is observed to decrease. When the spectroscopic investigations are coupled with electrical studies it is concluded that the glass samples doped with 2 mol% of Nb 2 O 5 are found to exhibit good semiconducting nature among the prepared glasses. Such glasses are suitable for fabrication of solid state devices. [ABSTRACT FROM AUTHOR]

Uniform hierarchical hollow microspheres of manganese carbonate (MnCO 3 ) have been synthesized by an efficient template assisted method using SiO 2 , manganese sulfate, and urea. Under a hydrothermal condition, manganese silicate is completely transformed into MnCO 3 , accompanied by dissolution of the inner SiO 2 core. The synthesized compounds have been characterized by powder X-ray diffraction (XRD), thermal analysis (TGA), and electron paramagnetic resonance (EPR) spectra. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have been used to investigate the surface morphology of MnCO 3 particles. The galvanostatic charge–discharge curves are used to evaluate the specific capacity of hollow sphere MnCO 3 . The initial discharge capacity was found to be 330 mA h g −1 at a current density of 44 mA g −1 . The capacity retention is significantly enhanced when compared with commercial MnCO 3 powder. [ABSTRACT FROM AUTHOR]

Highlights: [•] Various experiments were conducted on Al6061–TiB2 composite. [•] XRD and EDS studies confirm the crystalline size and elements present. [•] SEM, EDS and OM observations were used to study the characteristics. [•] Curve fitting and RSM design methods are effectively used to develop the model. [ABSTRACT FROM AUTHOR]

Abstract: The kinetic phase behavior and phase transformation paths of purified tristearoylglycerol (SSS), 3-palmitoyl-1,2-distearoyl-sn-glycerol (PSS) and 1,2-dipalmitoyl-3-stearoyl-sn-glycerol (PPS) were investigated in terms of polymorphism, crystallization and melting. The details of the phase transformation paths were obtained using the heating cycles of two sets of experiments: (a) cooling rate was varied and heating rate fixed and (b) cooling rate was fixed and heating rate varied. Kinetic effects were manifest in all measured properties, underscoring the complexity of the phase transformation paths for each TAG, and the intricate thermodynamics–molecular relationships. For the first time, XRD data obtained for SSS, PSS and PPS TAGs, cooled at rates higher than 0.5°C/min, suggested the formation of a transient structure similar to the so-called α2-phase which has been observed in mixed saturated–unsaturated TAGs quenched from the melt. The more stable phases (β′ in PSS and PPS, and β in SSS) were only observed for cooling rates lower than 1.0°C/min. The kinetic and thermodynamic differences observed in the crystallization, structure and melting of SSS, PSS and PPS are proposed to be mainly due to the disturbances introduced at the “terrace” level via methyl-end group interactions, i.e., the missing of two or four CH2 groups compared to SSS. The symmetrical SSS with a relatively flat “terrace” crystallizes preferably in the most stable β-form. Two missing CH2 groups at the sn-1 position (PSS) introduces enough structural disturbances to promote the relative prevalence and persistence of the β′-phase, and four missing CH2 groups at the sn-1 and sn-2 positions (PPS) is relatively too large of a disturbance and therefore favors the α-form. [Copyright &y& Elsevier]

Heat transfer and friction factor characteristics in a circular tube fitted with wire coil inserts are investigated experimentally using Al2O3/water nanofluid as the working fluid. The effects of the pitch ratio and nanofluid on the Nusselt number and the friction factor are determined in a circular tube with fully developed transition flow for Reynolds number in the range of 2500 to 5000. The experiments were performed using wire coil inserts having different pitch ratios with Al2O3/water nanofluid having 0.1% volume concentration of nanoparticles as the working fluid. Experiments using the plain tube and with wire coil inserts were also carried out with distilled water as the working fluid for experimental setup validation and comparison. The experimental results reveal that the use of nanofluids increases the heat transfer rate with negligible increase in friction factor in the plain tube and the tube fitted with wire coil inserts. In addition, empirical correlations are proposed based on the experimental results of the present study, which are found to be sufficiently accurate for prediction of the heat transfer and friction factor characteristics. [ABSTRACT FROM AUTHOR]

Abstract: Gallium nitride (GaN) epitaxial layers were grown with different V/III ratios by varying the ammonia (NH3) flow rate, keeping the flow rate of the other precursor, trimethylgallium (TMG), constant, in an MOCVD system. X-ray rocking curve widths of a (102) reflection increase with an increase in V/III ratio while the (002) rocking curve widths decrease. The dislocation density was found to increase with an increase in ammonia flow rate, as determined by hot-wet chemical etching and atomic force microscopy. 77K photoluminescence studies show near band emission at 3.49eV and yellow luminescence peaking at 2.2eV. The yellow luminescence (YL) intensity decreases with an increase in V/III ratio. Positron annihilation spectroscopy studies show that the concentration of Ga-like vacancies increases with an increase in ammonia flow rate. This study confirms that the yellow luminescence in the GaN arises due to deep levels formed by gallium vacancies decorated with oxygen atoms. [ABSTRACT FROM AUTHOR]

Abstract: Gallium nitride (GaN) nanocrystals were synthesized by nitridation of Ga-EDTA (ethylene diamine tetra acetic acid) complexes at different temperatures starting from 600 to 900°C. X-ray diffraction analysis, Fourier transform infrared spectroscopy and Raman studies revealed that the compound synthesized at 900°C consists of single-phase GaN nanocrystals with wurtzite structure. The change in morphology of the GaN crystals at different temperatures was observed using scanning electron microscopy. The transmission electron microscopy showed the average size of the crystalline particles to be ∼20nm. The room temperature photoluminescence exhibits band-edge emission of GaN at 3.46eV for all the samples. The present study demonstrates that the nitridation of Ga-EDTA complex method has significant potential for the synthesis of GaN nanocrystals as a simple and inexpensive method. [Copyright &y& Elsevier]

The mechanical properties of edible fats can be influenced by a series of factors, including the amount of solids, the polymorphism of the solid-state, as well as the microstructure of networks of polycrystalline particles created upon crystallization. This work demonstrates that for binary mixtures of the high-melting fraction of milk fat (HMF) with cocoa butter as well as for mixtures of HMF with the middle-melting fraction of milk fat, changes in the storage shear modulus (G′) are mostly controlled by the solid fat content (SFC), and the material’s microstructure. The SFC, in turn is a function of the phase behavior of the mixtures in the solid state. Experimental techniques used in the characterization of the different levels of structure are presented in this work. A model developed to explain mechanical properties of these materials taking into account all levels of structure is proposed. The polymorphism of the solid state did not seem to influence the mechanical properties of the fats, indicative of this material being structured as a network of weakly-attractive polycrystalline particles. Moreover, the mass fractal dimension of the network was closely related to the polymorphism of the solid state. [Copyright &y& Elsevier]

Multi-component glass ceramics with composition 29PbO–5Al 2 O 3 –1TeO 2 –10GeO 2 – (55–x) SiO 2 doped with different concentrations of CuO (0 ≤ x ≤ 1.0 mol %) were synthesized by melt quenching technique and subsequent heat treatment. These glass ceramics were characterized by X–ray diffraction, scanning electron microscope, differential thermal analysis, optical absorption, electron paramagnetic resonance, Fourier transform infrared and Raman studies. The absorption spectra of these glass ceramics exhibited a broad absorption band in the range 650–950 nm which is ascribed to 2 B 1g → 2 B 2g octahedral transition of Cu 2+ ions. A feeble band around 364 nm is also identified in the samples doped with CuO up to 0.6 mol% as being due to charge transfer between the two oxidation states Cu 2+ and Cu + of copper ions. The EPR spectrum recorded at room temperature exhibited a strong resonance signal at g ⊥ = 2.072 and a shallow quadruplet at about g ǁ = 2.401. FTIR and Raman spectra of the titled samples provide significant information about various structural units viz ., silicate, germanate, PbO 4 , PbO 6 , AlO 6 , TeO 4 and TeO 3 that are present in these ceramic matrix. Analysis of the spectroscopic investigations reveals that with an increase in the concentration of CuO up to 0.6 mol% copper ions do exist in Cu 2+ and Cu + states and they act as modifiers and net work formers respectively. Therefore, glass ceramic sample contains 0.6 mol% of CuO is favorable for memory switching action. [ABSTRACT FROM AUTHOR]

P 2 O 5 -PbO-Bi 2 O 3 -R 2 O 3 (R = Al, Ga, In) glasses doped with Pr 6 O 11 were prepared by melt quenching technique. The prepared glasses were characterized by X-ray diffraction, optical absorption, luminescence studies in both visible and near infra-red regions. Judd-Ofelt parameters have been evaluated for three glass systems from optical absorption spectra and in turn radiative parameters for excited luminescent levels of Pr 3 + ion are also calculated by using modified J-O theory. J-O intensity parameters follows the trend Ω 2 > Ω 6 > Ω 4 . Transition probability and branching ratio values are observed to high for 3 P 0 → 3 F 2 transition in Pr 3 + ion. The calculated laser parameters such as transition probability, scattering emission cross section, optical gain band width are found to high for the glasses mixed with Ga 2 O 3. Two dominant emission bands are observed in the visible region at about 611and 641 nm. The evaluated chromaticity coordinates lie in reddish orange region. Quantum efficiency of prepared glasses was measured by using radiative and calculated life times. Near infra-red emission spectra of the prepared glasses exhibit broad emission weak band in the range 1358–1591 nm which is suitable for optical telecommunication window devices. Cross relaxation channels are discussed and later verified by Dexter's theory. [ABSTRACT FROM AUTHOR]

Multi-component CaF 2 −ZnO–Bi 2 O 3 −P 2 O 5 glasses doped with different concentrations of CoO (ranging from 0 to 1.0 mol %) were crystallized by heat treatment. These samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), EDS and differential thermal analysis (DTA) techniques. The XRD patterns have indicated the presence of various phases viz., Ca 3 (PO 4 ) 2 , Bi 3 PO 7 , CaZn 2 (PO 4 ) 2 , Bi(PO 4 ), Zn 3 (PO 4 ) 2 , ZnCo(P 2 O 7 ), CaCoP 2 O 7 , ZnCo 2 O 4 , CoF 2 , Co 3 O 4 and CoF 3 . Conventional spectroscopic studies such as optical absorption, FTIR and Raman were also carried out on these glass ceramic samples. The analysis of these results has indicated that cobalt ions exist in both Co 2+ and Co 3+ states in the glass ceramic network. These studies have further revealed that the rigidity of the glass ceramic network decreases up to 0.6 mol% of CoO. Beyond this concentration the insulating strength of the prepared samples is found to increase. [ABSTRACT FROM AUTHOR]

The phase behavior of a model binary system made of OSO (2-stearoyl diolein) and MeS (methyl stearate) was investigated with differential scanning calorimetry and X-ray diffraction. The study is part of a series of investigations of unconventional additives such as TAGs (triacylglycerols) and dimers of TAGs with a demonstrated potential to significantly alter the crystallization of biodiesel. The TAG (triacylglycerol) was found to be effective in depressing the crystallization onset of the FAME (fatty acid methyl ester) significantly even at low concentration. OSO was shown to affect the crystallization of the mixtures strongly, and to dramatically alter their polymorphism. The system's phase diagram involved marked transformation lines including eutectics and solid–solid transitions. The molecular interactions were evaluated using a simple thermodynamic model. A mechanism for disruption of crystallization was proposed to be dependent on the peculiar geometry of OSO: the “straight” stearic acid participates easily in the lamellar packing of the equally “straight” FAME, whilst its kinked oleic acids effectively halt additional saturated FAMEs from participating due to steric hindrances. The findings of the study indicate that judicious loadings of TAGs which would target biodiesel's saturated FAMEs will have a substantial beneficial effect on the low temperature performance of the fuel. [ABSTRACT FROM AUTHOR]

In the present investigation we report the synthesis of a series of transparent glasses of composition 20Li 2 O 20PbO 45B 2 O 3 (15− x ) P 2 O 5 : x V 2 O 5 with eight values of x ranging from 0 to 2.5 mol%, and their characterization. X-ray diffraction (XRD) spectra reflected the amorphous nature of the glasses. Optical absorption, electron paramagnetic resonance (EPR) spectra and FTIR study of vanadyl ions in the present glass network have been analyzed. The optical absorption and EPR investigations have revealed that vanadium ions do exist in both V 4+ and V 5+ states and the redox ratio (V 4+ /V 5+ ) is observed to increase with the increase in concentration of V 2 O 5 . Dielectric properties viz., dielectric constant ε ′( ω ), loss tan δ , electrical moduli M ′( ω ), M ″( ω ), a.c. conductivity σ ac over an extensive scale of frequency and temperature have been investigated as a function of V 2 O 5 concentration. The dispersion of dielectric constant ε ′( ω ) with temperature has been interpreted by space charge polarization model. The dielectric loss and electrical moduli variation with frequency and temperature exhibited relaxation effects. These effects are ascribed to V 4+ ions. The a.c. conductivity of the prepared glasses is perceived to escalate with the hike in V 2 O 5 concentration whereas the activation energy for conduction exhibits a reverse trend. The conductivity mechanism is explained on the basis of polaronic transfer between V 4+ and V 5+ ions. The low temperature a.c. conductivity mechanism is elucidated by the quantum mechanical tunneling model. The growth in the values of dielectric parameters with raise in the concentration of V 2 O 5 is due to V 4+ ions which act as modifiers. The investigation of these results has indicated that at higher concentrations of V 2 O 5 , the VO 2+ ions in the glasses were present in octahedral sites with tetragonal compression and belong to C 4v symmetry. [ABSTRACT FROM AUTHOR]

The crystal structure development of jojoba-like esters incorporating either 1-decenoic acid and/or 1-decenol, namely octadec-9-enyl dec-9-enoate (JLE-281), and its isomer dec-9-enyl oleate (JLE-282) was investigated to reveal the effect of symmetry about the ester group on crystallization of aliphatic fatty monoesters. The phase transformation path was investigated with temperature-time resolved X-ray diffraction during stepped isothermal crystallization, and while cooling from the melt at a fixed rate. Startling differences in phase behavior were uncovered between the isomers. When stepped isothermals were used, selective extinctions occurred at a transition temperature for JLE-281 but not for JLE-282. The extinctions, which are due to dramatic changes in the electronic density of certain families of planes, indicate a phase transition attributed to a brusque rearrangement of the oxygen atoms in the crystal subcell. The phase transition did not occur when the JLEs were cooled continuously. The crucial role played by the position of the alkyl chain and its orientation relative to the easy rotation site of the C-O bond in the phase trajectories of the JLEs was particularly highlighted. [ABSTRACT FROM AUTHOR]

Abstract: A robust, well-defined and reproducible method to accurately measure the oil binding capacity (OBC) of structuring fats was developed. The method was validated using two oil/fat model systems, i.e., fully hydrogenated canola oil (FHCO) in canola oil (CO) (FHCO/CO) and fully hydrogenated soybean oil (FHSO) in CO (FHSO/CO). The mixtures were crystallized from the melt down to three different temperatures (15, 25 and 35°C) at constant rates of cooling and the OBC was measured after different periods of storage time. The critical concentration of hard fat at which the solid fat network is stable and effectively binds oil has been also measured for mixtures crystallized at temperatures close to room temperature, i.e., 25°C. Crystal structure, melting behavior, microstructure, and solid fat content of these binary systems have been investigated in relation to the OBC of the solid fat network using X-ray diffraction (XRD), differential scanning calorimetry (DSC), polarized light microscopy (PLM), and wide-line pulsed nuclear magnetic resonance (pNMR) techniques. The two model systems exhibited similar trends in OBC over time, a behavior attributed to their similar TAG composition and polymorphism. However, relatively smaller OBC values were achieved by the CO/FHSO compared to CO/FHCO samples, largely due to differences in their solid network structure. Four successive decreasing linear segments, identifying successive mechanisms of oil migration/binding, were observed in the experimental OBC versus fat weight fraction curves. The critical concentration of hard fat, at which the solid fat network is effective in binding oil, was also determined and found to be ∼6wt% for both systems. [ABSTRACT FROM AUTHOR]

Nickel ferrite NiFeO nanoparticles (NPs) were successfully synthesized by using nickel nitrate, ferric nitrate, citric acid, and ethyl cellulose as a surfactant by a simple sol-gel-assisted combustion method (SACM) and microwave-assisted combustion method (MACM). Structural, morphological, optical, and magnetic properties of the obtained powder were characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), photoluminescence (PL) spectroscopy, and vibrating sample magnetometry (VSM). XRD results show that the resultant powder was pure crystalline with cubic structure. The average crystalline size was found to be 18.8 and 10.2 nm synthesized by SACM and MACM, respectively. FT-IR spectra indicate the type of bonds between Ni-O and Fe-O (metal and oxygen). SEM images show that the morphology of the powder consists of well-defined structure. VSM results showed a ferromagnetic behavior of the sample. Antimicrobial activity of NiFeO nanoparticles was performed. Both sample 1 (SACM) and sample 2 (MACM) show good inhibition in the zone 100 μg/ml. While comparing, sample 2 shows high inhibition than sample 1. [ABSTRACT FROM AUTHOR]

The present paper includes the mechanical behavior of Al6061 alloy, Al6061–10TiB 2 composite and Al6061–10TiB 2 –1Gr and Al6061–10TiB 2 –2Gr hybrid composite prepared using a powder–metallurgy method. The samples were characterized by the Scanning Electron Microscope, Energy Dispersive Spectrum, X-ray Diffraction, Particle Size and Transmission Electron Microscope. Normally for Gr reinforced hybrid composite, the hardness and tensile strength decreased with increased Gr content. However, in this present study, the addition of TiB 2 with nano-Gr particle improved the hardness and tensile strength up to some extent. The tensile fractured specimens were also analyzed using SEM. An acoustic emission (AE) technique was employed in all the tensile test specimens to monitor the acoustic energy released during the deformation process and for the early crack detection. [ABSTRACT FROM AUTHOR]

AlN layers of thickness of about 2 μm have been grown with AlN nucleation layers (NLs) on (001) sapphire substrates using metal organic chemical vapor deposition. Increasing the AlN-NL deposition temperature from 850 to 1250 °C has been found to have significant effect on the surface morphology and the structural quality of the AlN layers. The surface morphology of the AlN-NLs and the AlN layers has been assessed using atomic force microscopy (AFM). The AFM images of the AlN-NLs reveal the coalescence pattern of NLs. AFM images of the AlN layers and the in-situ reflectance measurement disclose the surface morphology and the growth pattern of the AlN layers, respectively. Smooth surface with macro-steps and terrace features has been achieved for the AlN layer grown on the NL deposited at 950 °C. The structural quality of AlN layers has been studied by high resolution X-ray diffraction and Raman spectroscopy. The screw dislocation density from (002) reflection and the average edge dislocation density from (102), (302) and (100) reflections of the AlN layer on NL deposited at 950 °C are estimated to be 9×10 7 cm −2 and 4.4×10 9 cm −2 , respectively. Lateral correlation length ( L ) is calculated from the (114) reciprocal space mapping of the AlN layers and correlated with the edge dislocation density of the AlN layers. Raman E 2 (high) phonon mode indicates compressive strain in the AlN layers grown on the NLs deposited at various temperatures. From this work, it has been inferred that the uniform coalescence of the nucleation islands and the complete coverage of AlN-NL determine the surface morphology and the structural quality of the subsequently grown AlN layers. [ABSTRACT FROM AUTHOR]

Abstract: The binary phase behavior of purified 1,3-dilauroyl-2-stearoyl-sn-glycerol (LSL) and 1,2-dilauroyl-3-stearoyl-sn-glycerol (LLS) was investigated at a slow (0.1°C/min) and a relatively fast (3.0°C/min) cooling rate in terms of melting and crystallization, polymorphism, solid fat content (SFC), hardness and microstructure. Much of the behavior of the system is explained by its polymorphism and the influence of thermal processing. The α-form and the β′-form of a double chain length structure were detected in the mixtures cooled at 3.0°C/min, whereas only the β′-form was detected in those cooled at 0.1°C/min. X-ray diffraction data as well as thermodynamic data propose that the most stable phases are promoted by the symmetrical LSL. The measured trends in structural characteristics, thermal properties, SFC, relative hardness and microstructure delimit three groups of mixtures which imply a competition between the stabilizing effect of LSL and disordering introduced by kinetic effects: (a) LLS-rich mixtures with LSL molar fractions (X LSL) less than 0.3, (b) mixtures with X LSL clustered around 0.5 and (c) LSL-rich mixtures with X LSL ≥0.7. The balance between ordering and kinetic effects determines the polymorphism of the mixtures, which in turn determines the behavior of the LSL/LLS system. The kinetic phase diagram of the LSL/LLS binary system constructed using heating differential scanning calorimetry thermograms displayed a singularity at the 0.5LSL molar fraction which delimits two distinct behaviors: eutectic behavior in one region and monotectic behavior in the other. The molecular interactions, as depicted by a non-ideality parameter of mixing obtained from a thermodynamic model based on the Hildebrand equation, suggests an almost ideal mixing behavior and a moderate tendency to the formation of unlike-pairs in the liquid state. [Copyright &y& Elsevier]