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In this article, with an overview to the dynamics of the homogeneous and isotropic cosmology for the usual and phantom scalar fields, we investigate the model of exponentially damping fields. We obtain the extract solutions for the potential function, the scale factor of the model and the dynamics of the parameter of the equation of state. We present two proposals for the scalar field to achieve the exponential potential function in terms of time and extract Hubble’s cosmological parameters, scale factor and equation of state parameter for each model. At the end of the work, we turn our attention to the quantum cosmology of the model with time-damped exponential potential and form the Wheeler-Dewitt equation with some new variables. The Wheeler-DeWitt wave packets with the Gaussian weight function are obtained for the scalar fields in different cases and draw the probability function of each one. [ABSTRACT FROM AUTHOR]

Piezoelectric vibration-based energy harvesters (PVEHs) are designed to convert mechanical energy into electric energy. Researchers deal with issues like inefficient amount of energy and frequency bandwidth. Optimizing and widening the PVEH can address the issues. As a modification to the dynamic magnification concept of conventional PVEH, a novel integrated oscillatory multisystem of cantilever-oscillator-spring is proposed. In this project maximizing the widened effective frequency bandwidth with respect to the oscillator mass and spring constant is the main goal. The closed-form voltage function obtained numericallyanalytically is expensive in terms of computational time and cannot be used in the genetic optimization. In this regard, soft computing techniques is adopted. Utilizing adaptive-neuro-fuzzy-inferencesystem (ANFIS), a regressor model is designed to estimate voltage function evaluations in the genetic optimization, such fuzzy system is tuned with decent type and number of membership functions according to the root-mean-square-error criteria. Fuzzy inference system (FIS) is implemented using 64 and 49 fuzzy rules derived from Gaussian membership functions (MFs) and passed to the genetic algorithm initiating with 100 iterations and 30 populations. Using roulette wheel, tournament, and random selection methods, optimal values of the mass and stiffness ratios are found to yield the most widened frequency bandwidth. Findings reveal integration of the proposed oscillator-spring subsystem drastically reinforces utmost generated voltage. Furthermore, tuning parameters result the maximum widened frequency bandwidth which improves the harvester performance up to 3 times the conventional values. [ABSTRACT FROM AUTHOR]

• The shoot tips of Phalaenopsis are rooted under eight-light qualities. • The survival rate of rooted plants under fluorescent and green light was highest in ex vitro. • The best growth and largest cells of the cortex zone of roots were observed under fluorescent and green light. • Monosaccharide content was highest under red+blue, fluorescent, and green light, respectively. The emergence and application of light-emitting diodes (LEDs) as an adjustable light source, developed our knowledge about the role of various light parameters in plant growth and development. Our aim was to evaluate the rooting of regenerated shoot tips and subsequent survival rate of Phalaenopsis tissue cultured plantlets by analyzing the monosaccharide profile and anatomical evaluation of regenerated roots under eight-light wavelengths including red (R), blue (B), green (G), red+blue (RB), red+green (RG), blue+green (BG), white (W), and Fluorescent (FL). The results revealed different responses depending on the type of light quality. Rooting traits were better under FL and G light; however, the maximum root length was obtained under white LED. In general, rooting was not suitable under RG light. Despite the high fresh and dry weight of roots under RB light, leaf length decreased. Leaf length was better under FL and G followed by R and W and decreased under spectra containing blue light. Also, the content of chlorophyll under FL and G was balanced and the levels of anthocyanins and carotenoids in FL and G were lower than in blue light and treatments containing blue. The highest content of monosaccharides (glucose, xylose, galactose, rhamnose, arabinose, and mannose) was obtained under RB and FL followed by the G light. The lowest content of monosaccharides was recorded under RG and BG. Analysis of the root showed that the size of the cells in this area was larger under fluorescent and green light. Expanded leaves, balanced monosaccharide and pigment levels, and large cells of the root cortex were common features of FL and G light, which also led to the highest ex vitro survival rate. [ABSTRACT FROM AUTHOR]

• Stenting is the simultaneous use of grafting and cutting methods in one action. • The different stem parts as rootstock are important for the success of stenting. • The different stem parts affect phenolic compounds in the biosynthesis of lignin. • Antioxidant enzymes play a key role in graft union and adventitious root formation. • The bottom and middle positions of stem should be used to multiply by stenting. Stenting is a commercial propagation method for roses that combines grafting and cutting in one action and the resulting plantlet is named 'stentling'. Several physiological and biochemical factors can significantly influence graft union healing and adventitious root formation. The effect of rootstock and its cutting-prepared region have not been well studied for successful stenting. We provide a comprehensive overview of the physiological and biochemical aspects of the stenting process, utilizing rootstock positions as the source of variation among treatments. Morphophysiological and biochemical assays were performed to evaluate the effect of three different stem parts (bottom, middle, and top) of 'Natal Briar' as rootstock on graft union healing and adventitious root formation of the rose stentlings. When the rootstock originating from the bottom and middle positions improved the physiological, biochemical, and morphological responses of the stentling, significantly. In this regard, the improved biochemical properties, including total soluble sugars, total phenolic and flavonoid contents, phenylalanine ammonia-lyase, peroxidase and lignin content seem to play a special role in the success of grafting and subsequently the adventitious root formation. Assessing morphophysiological and biochemical parameters paves the way for a better understanding of the mechanism of successful stenting. [ABSTRACT FROM AUTHOR]

This paper carefully evaluates the electrocatalytic activity of Sr 2 FeMo 0.5 Mn 0.5 O 6 (SFMM) double perovskite as a candidate to substitute the state-of-the-art Ni/YSZ fuel electrode. The electrochemical performance of a 40% SFMM/CGO composite electrode was studied in CO/CO 2 and H 2 with different oxygen partial pressure. Two different cell configurations are prepared at a relatively low temperature of 800 °C to increase the electrochemically active surface area. The cell was supported with a 150 μm 10Sc1CeSZ electrolyte in the first configuration. The cell in the second configuration was made by applying a 400 nm thin 8YSZ layer on 150 μm CGO electrolyte to improve the electrolyte ionic conductivity. Improving catalytic activity with increasing oxygen partial pressure is a key characteristic of the developed electrode. The polarization resistance of about 0.34 and 0.56 Ω cm2 at 750 °C in 3%H 2 O + H 2 and 60% CO/CO 2 makes this electrode a promising candidate for SOCs application. • A crack-free SFMM/CGO composite fuel electrode prepared at 800 °C without the formation of the SrZrO 3 insulator phase. • The SFMM double perovskite shows a stable structure at high oxygen partial pressure. • The electrochemical behavior obtained in CO/CO 2 and H 2 with 3–20 vol% H 2 O. • The relatively small polarization resistance makes it a candidate for substitution of the state-of-art Ni/YSZ electrode. [ABSTRACT FROM AUTHOR]

Micro-electro-mechanical-systems scale robots are prone to impulsive disturbances during operation. Such disturbance leads to adverse oscillations of the robot manipulator. So, it is essential to mitigate and control such unwanted oscillations. On the other hand, to capture size dependencies of such robot elements, it is required to adopt nonclassical models. To address these cases, robot manipulator is modeled as a mechanical rod, comprehensive rod models are utilized, proportional integral derivative (PID) controller is designed, and the time-domain response of the system is simulated in MATLAB. Results show that adopting proper gain values of the PID controller leads to total rejection of the pulsive disturbances. However, findings conceal the importance of the nonclassical rod model such that strain gradient (SG) model shows less oscillatory amplitude than the classical theory (CT) model. While considering the nonlocal model effects (NL), such undesired vibrations are bigger than CT model. In other words, meanwhile, a simple PID controller can reject the disturbance for SG models; a stronger controller should be adopted to reject such pulsive disturbances with NL models. Eventually, it is valuable to note that to suppress unwanted oscillations in small-sized robots, PID closed-loop feedback controller is a decent choice because of the simplicity and less costs. Application of successful control design alongside the proper nonclassical theory leads to neutralizing the disturbances and increases the robot manipulator precision. [ABSTRACT FROM AUTHOR]

Free lateral vibration analysis of gyroscope model is studied in this paper. This gyroscope is modeled as a rotating simply-supported beam which is under an initial thermal stress. Thermo-mechanical properties of the beam are mutable with temperature. For the first time beam is supposed to rotate around a fixed axis in which rotational displacement field is expressed as a liner function in terms of combination of axial and lateral displacements. Dynamic-vibration equations of the proposed model are derived based on the Hamilton's principle. Due to the symmetry of the system, Navier approach is adopted as solution approach. For evaluation, current results are compared with the results available at the technical literature showing high level of accuracy. New results emerged from of this paper imply effects of rotation of the beam and thermal stresses simultaneously upon the dynamic response of beams: different values of lateral velocity factor strongly affect the frequencies of the system; however, axial velocity factor does not play any role. In short, rotation of the beam accompanied by thermal stresses are affecting the dynamic behavior of the beam-type gyroscope remarkably. Consideration of thermal stresses and rotation rates are the most vital factors in the design of a gyroscope. [ABSTRACT FROM AUTHOR]

Forced longitudinal vibration response of nonlocal strain gradient (NLSG) rods is scrutinized and compared with nonlocal (NL), strain gradient (SG), and classical (CL) rods. In this respect, size-dependent kinematics and extended Hamilton's principle are utilized to derive governing equations of motion. For the first time, forced longitudinal vibratory behavior of non-classical and classical rods is presented including three different types of non-harmonic forcing functions: unit impulse, unit step, and unit ramp. Forcing terms are functions of both temporal and spatial domains. Nonlocal strain gradient and nonlocal rod models take into account the Laplacian of the external forcing term as well. This implies that in models including nonlocal effects (NL, NLSG-h, s, n), forcing term is reduced by the order of its Laplacian with respect to spatial variables. Effect of non-classical parameters over time-domain response of the system is analyzed in details. Results are compared with benchmark for the sake of evaluation. This implies the necessity of adopting proper values of non-classical theory and corresponding parameters through analysis of forced oscillations of small-scaled size-dependent rods. Such external excitations are modeled using spatial Dirac delta function as a concentrated force applying at the critical point of mode shape function. Findings of this research reveal the underlying impact of non-classical theorems along with corresponding non-classical parameters over the prediction of the response of size-dependent rod elements for wide range of applications such as in musical instruments, navigating equipment, gyroscopes, control of robotics, sensors and actuators, resonators, energy harvesters, and vibration control systems. [ABSTRACT FROM AUTHOR]

In this technical paper, forced longitudinal vibration response of non-local strain gradient (NLSG) rods is obtained and compared with that of non-local (NL), strain gradient (SG), and classical (CL) rods. To this end, size-dependent kinematics along with extended Hamilton's principle are used to derive governing equations of motion. Classical clamped-free and non-classical clamped-forcing free-strained boundary conditions are adopted. For the first time, forced longitudinal vibratory behavior of non-classical and classical rods subjected to harmonic external loading is presented. In investigation process, effects of non-classical parameters over mechanical impedance, resonance frequency, mechanical frequency response function (FRF) (transmissibility), time period, and time-domain response are determined. Effect of non-classical parameters over time-domain response of the system is analyzed in details. Results are compared with benchmark approving good level of accuracy, disclosing the intensifying effects of material length scale parameter over natural frequency as well as mechanical impedance and resonance frequency. Meanwhile, non-local parameter leads to decrement of natural frequency, mechanical impedance and resonance frequency. Furthermore, it is realized that crest value of transmissibility is not predictable based on frequency and/or impedance variations with respect to non-classical parameters; and requires separate analysis for individual cases. In other words, a pattern referring to gradations of natural and resonance frequencies, mechanical impedance and non-classical parameters and rod models is detectable; however, such patterns do not hold for estimation of mechanical frequency response function (transmissibility peak value). Moreover, stiffness-softening and stiffness-hardening effects are the most impressive and influential factors over transmissibility peak values which can be highly important for energy harvesting rod analysis. Findings of this research point to the importance of proper non-classical theorems along with corresponding non-classical parameters to predict the response of small-scaled rods for wide range of applications in control of robotics, musical instruments, navigating equipment, space wheels, fly wheels, gyroscopes, sensors, actuators, resonators, vibration isolators and energy harvesters. [ABSTRACT FROM AUTHOR]

In this research paper, lateral vibration analysis of simply-supported microbeam under thermal stress is investigated. Microbeam model is presented based on the modified couple stress theory and Timoshenko beam theory. Thermo-mechanical properties of the microbeam are assumed variable by temperature shifts. This means that any shift in the temperature leads to different thermo-mechanical properties. Thermal stress is induced to the system due to the temperature difference between the lateral surfaces and the system itself. Major novelty of the current research includes the variable nonclassical length scale parameter. The mentioned parameter derived from the modified couple stress theory is assumed variable based on the power law. Hamilton's approach is taken to derive the system of governing equations of motion. The mentioned coupled system of equations is solved using the Navier method. For verification, current results are compared with those available at benchmark. This research implies the importance of temperature, distribution profile of nonclassical length scale parameter, and slenderness ratio upon dynamic responses of the present model based on both classical and modified couple stress theories. [ABSTRACT FROM AUTHOR]

Nanostructured Sr 2 FeMoO 6 double perovskite was synthesized by the sol-gel combustion method. X-ray diffraction results showed that SrMoO 4 starts to form at 450 °C, and the formation of single-phase double perovskite with a tetragonal I4/m space group occurs at a relatively low temperature of 750 °C. Rietveld refinement by FullProf software showed the mean crystallite size of 49 nm, and unit cell parameters of a = b = 5.577 Å and c = 7.918 Å for the synthesized Sr 2 FeMoO 6. Analysis of the FTIR spectra revealed that with mechanical activation process, the peak corresponding to the C–O band at 2341 cm−1 vanishes and intensity of carboxyl group (1445 cm−1) and nitrate ions band (1396 cm−1) are affected. The presence of the peaks related to the vibration of metal ions bands at octahedral sites at 644 and 831 cm−1 confirms the evolution of Sr 2 FeMoO 6 double perovskite structure. Scanning electron microscope images showed that the Sr 2 FeMoO 6 powder processed at 750 °C in 5%H 2 /N 2 atmosphere has a mean particle size of about 250 nm. It was observed that the saturation magnetization increases to the high value of 18 emu.g−1 in the ordered structure at 800 °C. High Curie temperature of 423 K in the prepared sample makes it a promising candidate for the magnetocaloric applications. [ABSTRACT FROM AUTHOR]

Development of automotive three-way catalysts (TWC) is a critical research topic owing to the increasingly stringent emission regulations together with the price and scarcity of precious metals. Among different materials classes, perovskite-type oxides are known to be valuable alternatives because of their high catalytic activities and thermal stability. The interest in doped lanthanum ferrite perovskite as a catalyst is the concept of regeneration of catalyst nanoparticles, which makes it be used efficiently in automobile exhaust for longer duration in comparison to the conventional TWCs. B-site cation regeneration prevents particle growth and sulfur poisoning; hence, the consumption of precious metals will be reduced without lowering the catalytic performance. The aim of this study is to optimize the characteristics of a LaFe0.6Co0.4O3 (LFC) washcoat layer on a cordierite (2MgO.2Al2O3.5SiO2) monolithic substrate through dip coating of the slurry of amorphous and calcined nano-sized LFC particles. Experiments have been conducted to find the optimum amount of viscosity of the slurry, number of dipping repetitions, and suspension time in order to get the highest specific surface area and adherence to the substrate. Also, differences between a slurry with amorphous and calcined powder, precipitation agent and calcination temperature are investigated. It was found that a slurry with 8% w/w of LFC powder, 2% w/w of PVA, 1% w/w of HNO3, and 7.8% w/w of glycerol in water yields suitable slurry characteristics for the dip-coating purpose. SEM pictures were acquired to find out the morphology of the washcoat layer. By repeating the dip-coating process for two times with the calcined powder, a uniform and porous layer is formed on the monolithic substrate with particle size of around 200 nm after sintering at 900 °C. [ABSTRACT FROM AUTHOR]

The effects of introducing La2NiO4 nanocatalyst on the electrochemical performance of La0.8Sr0.2MnO3 are investigated under solid oxide electrolysis cell and fuel cell modes, as well as open circuit voltage. Extracted data from impedance spectroscopy are interpreted with the analysis of distribution of relaxation times. La2NiO4 infiltration effectively reduces the activation energy of the oxygen reactions from 1.35 to 0.99 eV. It also changes the rate controlling process of the overall reaction. Polarization behavior of La2NiO4‐infiltrated La0.8Sr0.2MnO3 electrode shows superior performance under electrolysis mode compared to the fuel cell mode. Drastic increase in the size of low frequency arc during anodic current passage in the non‐infiltrated La0.8Sr0.2MnO3 electrode is hampered by infiltration of La2NiO4 nanocatalyst. By applying anodic current on infiltrated La0.8Sr0.2MnO3, no displacement is observed in the position of high frequency peaks in the distribution of relaxation time graphs and only a small increase in height occurs for the low frequency arc. Additionally, La2NiO4‐infiltrated electrode impressively decreases overpotential by 74% compared to the non‐infiltrated one under electrolysis mode at 800°C. [ABSTRACT FROM AUTHOR]

In this study, Ag-ceria, Co-ceria, and Ba0.5Sr0.5Co0.8Fe0.2O3 nano-catalysts were introduced onto the structure of La0.6Sr0.4Co0.2Fe0.8O3−δ cathode of solid oxide fuel cells through infiltration technique and the electrochemical features of the infiltrated cathodes were examined by electrochemical impedance spectroscopy and analysis of distribution of relaxation times in the temperature range of 500–800 °C. The results revealed that Ba0.5Sr0.5Co0.8Fe0.2O3 exhibits considerable promoting behavior in the upper portion of the studied temperature range, while Co-ceria demonstrates significant catalytic activity for the oxygen reduction reaction at lower temperatures probably due to the active valence exchange of cobalt species in the spinel structure of cobalt oxide. Analysis of distribution of relaxation times revealed that low frequency arc of the impedance spectra is effectively hampered as a result of Ag-ceria and Co-ceria infiltration. Cathodic polarization of the infiltrated cells showed stable performance of the infiltrated electrodes over 50 h at 700 °C. [ABSTRACT FROM AUTHOR]

Abstract La 0.75 Sr 0.25 Cr 0.5 Mn 0.5 O 3-δ /ZrO 2 -8 mol% Y 2 O 3 (LSCM/YSZ) was used as the fuel electrode of solid oxide electrolyzer cell and its performance during steam electrolysis and CO 2 /H 2 O co-electrolysis at 850 °C was analyzed. Results from polarization and electrochemical impedance spectroscopy data showed that the electrode exhibits better performance when the steam and CO 2 concentration in the carrier gas were 20% and 9%, respectively, rather than when the carrier gas only had 20% steam. In order to further enhance the performance of the electrode, LaFe 0.6 Co 0.4 O 3 nanoparticles were introduced onto the LSCM/YSZ scaffold by means of infiltration technique, with different concentration of LaFe 0.6 Co 0.4 O 3 precursors. The field emission scanning electron microscopy images and Energy-dispersive X-ray spectroscopy confirmed the formation of nanoparticles of catalytic materials in the fuel electrode. Polarization and impedance data verified the promotion of the electrochemical behavior of LSCM/YSZ fuel electrode, during both steam and co-electrolysis; for example, by using a 0.6 mol L−1 LaFe 0.6 Co 0.4 O 3 precursor for infiltration, 80% and 75% decrease in the polarization resistance occurred at steam and co-electrolysis modes, respectively at 850 °C and under potential of −1 V. Moreover, analysis of distribution of relaxation times of impedance data showed that three distinct processes occurred during steam and co-electrolysis on the infiltrated electrodes, which were related to charge transfer process at high frequency region, gas diffusion at medium frequency region and reactant gas adsorption and surface diffusion of activated species from gas dissociation to triple phase boundaries and ionic diffusion at low frequency region. Graphical abstract Image 1004 Highlights • Electrolysis performance of LSCM/YSZ was highly H 2 O/CO 2 ratio-dependent. • LSCM/YSZ showed better performance during co-electrolysis than steam electrolysis. • DRT showed that by LFC infiltration three distinctive peaks emerged. • LFC Infiltration drastically reduced R p during both steam and co-electrolysis. [ABSTRACT FROM AUTHOR]

Free longitudinal vibration analysis of a rotating rod based on the Eringen's nonlocal elasticity is studied in this paper. Rod is supposed to rotate around a fixed axis with a constant angular velocity. To capture the effect of the rotational motion into analysis of the continuous system, a linear proportional relation is introduced between axial and angular velocities. For the first time the mentioned relation is presented based on the internal motions of the infinitesimal element. This novelty makes the rotational displacement as a dependent function of axial displacement playing a significant role through the analysis. Variational approach is adopted to derive the equations of motion for clamped-clamped and clamped-free boundary conditions. For verification of the results obtained from the Galerkin approach, comparison with technical literature is reported. Finally current results illustrate the dependency of the dynamic-vibration analysis of the presented system on the nonlocality and the rotational velocity parameter. This dependency shows the decrement of the frequency with increment in both the angular velocity and the nonlocal parameter. As a result, the mentioned parameters are key factors in the design and analysis of such systems. [ABSTRACT FROM AUTHOR]

In this paper, thermally-excited, lateral free vibration analysis of a small-sized Euler-Bernoulli beam is studied based on the nonlocal theory. Nonlocal effect is exerted into analysis utilizing differential constitutive model of Eringen. This model is suitable for design of sensors and actuators in dimensions of micron and submicron. Sudden temperature rise conducted through the thickness direction of the beam causes thermal stresses and makes thermo-mechanical properties to vary. This temperature field is supposed to be constant in the lateral direction. Temperatures of the top and bottom surfaces of the system are considered to be equal to each other. Governing equation of motion is derived using Hamilton’s principle. Numerical analysis of the system is performed by Galerkin’s approach. For verification of the present results, comparison between the obtained results and those of benchmark is reported. Numerical results demonstrate that dynamic behavior of small-sized system is been effected by temperature shift, nonlocal parameter, and slenderness ratio. As a result, taking the mentioned parameters into account leads to better and more reliable design in miniaturized-based industries. [ABSTRACT FROM AUTHOR]

Abstract The electrochemical performance and stability of La 0·8 Sr 0·2 MnO 3 oxygen electrodes infiltrated with La 2 Ni 0·5 Co 0·5 O 4 (Ruddlesden-Popper) and LaNi 0·5 Co 0·5 O 3 (perovskite) nano-particles were studied under cyclic solid oxide electrolysis cell and solid oxide fuel cell modes. Electrochemical impedance spectroscopy and analysis of distribution of relaxation times were utilized to investigate the effect of addition of catalysts with Ruddlesden-Popper and perovskite structures on the reversible operation of electrochemical cells. Results indicated that addition of La 2 Ni 0·5 Co 0·5 O 4 nanoparticles has more impact on polarization resistance reduction as compared to LaNi 0·5 Co 0·5 O 3 in cyclic operation, probably due to the facile oxygen transport in the rock salt layer of Ruddlesden-Popper structure. Analysis of the polarization resistance fluctuations shows a better stability in Ruddlesden-Popper structure-infiltrated electrodes as compared to perovskite structure. The difference between maximum and minimum of polarization resistances (i.e. fluctuations) in cyclic operation is reduced significantly by introducing Ruddlesden-Popper-structured lanthanum nickel cobaltite nanoparticles. Graphical abstract Image 1 Highlights • Significant improvement in the reversible operation of LNC infiltrated LSM. • Reduced polarization resistance by LNC infiltration is disclosed from DRT analysis. • Ruddlesden-Popper LNC infiltration is more effective compared to perovskite LNC. [ABSTRACT FROM AUTHOR]

Abstract A new method entitled Friction Stir Radial Backward Extrusion (FSRBE) is presented for processing fine-grained tubes. In FSRBE technique, an initial pure copper billet is placed inside a cylindrical chamber. The billet is pushed toward a rotating tool which results in radial and backward flow of the material while is frictionally stirred. The microstructure evolution during FSRBE was investigated through experimental observations and cellular automaton (CA) modeling. The observations reveal that the microstructure with initial grain size of 75 μm was refined to a fine-grained structure with an average grain size of 12 μm. The results of tensile tests demonstrate slight improvement in the value of yield and ultimate strength, elongation and microhardness. The microstructural evolution during FSRBE processing in the micro-level was studied using a coupled cellular automaton algorithm and finite element model. First, the macroscopic plastic flow behavior of material during FSRBE was calculated using FEM simulation method. Next, by tracing the plastic strain, the strain rate and temperature, in the deformation domain of cellular automaton, the DRX kinetics of pure copper is obtained in a devised post-processing step. The microstructure observations showed that the proposed model predictions were in reasonably good agreement with the experimentally obtained results. [ABSTRACT FROM AUTHOR]

The electrochemical performance of a La 0.8 Sr 0.2 MnO 3 (LSM) cathode electrode of solid oxide fuel cells (SOFCs) was promoted by the infiltration of metallic (Ag) and ceramic (La 0.8 Sr 0.2 FeO 3 (LSF), CeO 2 ) nano-catalysts. Electrochemical and microstructural techniques were used to investigate the effects of the addition of the infiltrated materials. The SEM observations showed that a well-dispersed arrangement of catalyst nano-particles is formed on the micron-sized LSM backbone. Electrochemical impedance spectroscopy (EIS) along with the analysis of distribution of relaxation time (DRT) and polarization measurement were conducted using a three electrode configuration setup. The EIS results revealed that the effect of the Ag nano-catalyst in lowering the polarization resistance is more sensible at lower temperatures, whereas LSF has more impact on the reduction of polarization resistance at higher temperatures. The best performance enhancement was achieved by the co-infiltration of Ag-ceria into the LSM electrode. The co-infiltration of Ag and ceria reduced the polarization resistance of the electrode to 2.5% of that for the pure LSM electrode. Furthermore, the infiltration of Ag solution reduced the electrode overpotential by about 114% at 700 °C. [ABSTRACT FROM AUTHOR]

LaFe x Co (1-x) O 3 nanoparticles were prepared via a coprecipitation method and the effects of Pd dopant along with the type of alkaline agent on the powder particle characteristics have been studied. The catalytic activities of the synthesized perovskites for the CO and CH 4 oxidation were also studied. X-ray diffraction (XRD) patterns confirmed the formation of a single-phase orthorhombic perovskite structure in the synthesized samples. Field emission scanning electron microscopy (FESEM) and BET analyses showed that using ammonia as the precipitant yields finer particles with higher specific surface areas for both un-doped and Pd-doped samples. FESEM micrographs also indicated that incorporation of Pd decreases the mean particle size of the perovskite powders. Raman spectroscopy results demonstrated that palladium occupies the B octahedral sites of the perovskite lattice. H 2 temperature programmed reduction (H 2 -TPR) and O 2 temperature programmed desorption (O 2 -TPD) results revealed that Pd-doping not only improves the reducibility of the iron and cobalt cations, but also boosts the number of mobile lattice oxygen species. Transmission electron microscopy (TEM) analysis confirmed formation of metallic Pd clusters having the size of 2–7 nm on the surface of Pd-doped perovskite under the reductive atmosphere. LaFe 0 . 57 Co 0 . 38 Pd 0 . 05 O 3 sample co-precipitated by NH 4 OH enjoys the highest catalytic activity for both CO and CH 4 oxidation. [ABSTRACT FROM AUTHOR]

In this paper free vibration analysis of functionally graded micro-beam is investigated based on the modified couple stress theory. The model is established using the Euler-Bernoulli beam theory. The thermal and mechanical properties of the micro-beam are assumed to be temperature-dependent and vary smoothly through the thickness direction. The power law distribution is used for exerting the material gradation. The micro-beam is initially stressed by temperature change thorough the thickness. The temperature field is supposed to be constant in the cross section plane. The induced thermal stress, and the power index affect dynamic responses of the micro-beam. The Hamilton's principle is utilized to derive the governing equation of motion, and Galerkin's method is used in the solution procedure. Upon using the modified couple stress theory, non-classical results are obtained, moreover by neglecting the non-classical parameter, classical results are reported. For verification, the numerical results are compared with those of benchmark. Present results denote the vitality of temperature and material gradation upon dynamic responses of micro-systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • The electrocatalysts anodes using base metals by sol-gel method were synthesized. • The anode of the CoSb 2 O x electrocatalyst has the best electrocatalytic activity. • The electrocatalytic CoSb 2 O x and NiCoSb 4 O x anodes have high durability. • The CoSb 2 O x electrocatalytic anode had the most extended life. • The anode of the NiCoSb 4 O x electrocatalyst has the highest ECSA. The electrocatalysts anodes using base metals on titanium substrate by sol–gel method were synthesized as an alternative due to the scarcity of noble metals, such as iridium and ruthenium. For this purpose, the cobalt antimonate and nickel–cobalt antimonate stable electrocatalysts to carry out the oxygen evolution reaction (OER) were developed. LSV showed that the cobalt antimonate electrocatalyst has an intrinsic potential of 1.615 V vs. RHE. For the cobalt antimonate electrocatalyst, the potential corresponding to the current density of 10 mA.cm−2 is 1.791 V vs. RHE. The stability of all synthesized anodes at a current density of 10 mA.cm−2 was at least 200 h (more than 8 days) while the CoSb 2 O x electrocatalyst displayed a superior lifetime for at least 650 h (more than 27 days) at a current density of 100 mA.cm−2. According to the EIS data at the potential of 1.791 V vs. RHE, the nickel–cobalt antimonate had the lowest charge transfer resistance (R ct) of 4 Ω.cm2. The combination of the above results confirms the capability of the proposed anode as a substitute for precious ones. [ABSTRACT FROM AUTHOR]

Ziziphus jujuba Mill is an important medicinal plant which is of high importance in medicinal industry due to containing mucilage, different types of vitamin, pectin, alkaloid, phenolic compounds and fatty acids. The current study was conducted to evaluate phylogenetic relations of jujube accessions using morphological, phytochemical and AFLP molecular markers. In morphological and phytochemical experiments, minimum, maximum, and average of fruit weight, were respectively 1.52, 2.99 and 2.31 g. In the same way, the minimum (1.3 g), maximum (2.65 g) and average (1.99 g) of fruit flesh weight were observed in accessions. The lowest (11.58 %) and highest (28.85 %) of mucilage quantity were related to Kalaghneshin1 and Kasva accessions. Simple correlation analysis of the traits showed that there were significant positive and negative correlations among some important traits including the positive correlation between the amount of mucilage and flesh to kernel ratio and kernel shape, and negative correlation between mucilage rate and kernel weight and diameter and fruit shape. Analysis of factors based on Varimax method defined four factors of fruit volume, kernel, fruit flesh and mucilage. Cluster analysis classified accessions into four groups, and segregated three groups with Esfahani, Qomi and Mazandarani origins. In a similar matrix molecular experiment using Jaccard coefficient, cluster analysis was performed by using UPGMA algorithm. 12 out of 15 pairs of AFLP primer showed polymorphism, with these primers producing 689 bands, out of which 44 bands presented polymorphism. Based on the results obtained from dendrogram, the studied accessions were divided into 8 discrete groups at similarity level of 0.75. AFLP marker could clearly cluster three groups of Qom, Esfahan and Khorasan. The results obtained from cluster analysis were confirmed by the principal component analysis. Two groups of Qom and Esfahan were distinctively separated in all markers; therefore these regions (central regions) can be introduced with high probability as one of the origins of jujube. In general, diversity of traits, efficiency of markers and high correlation between the makers were considerable in segregation and separation of the accessions, and can provide an appropriate foundation for breeding of this valuable medicinal plant. • The significant positive correlation between the amount of mucilage and flesh to kernel ratio and kernel shape. • Identification of superior genotypes in terms of desirable fruit characteristics and mucilage amount. • Determining the four factors of fruit volume, kernel, fruit flesh and mucilage, based on analysis of factors. • Separation of two groups of Qom and Isfahan in all markers and introducing the central regions as one of the main origins of jujube. [ABSTRACT FROM AUTHOR]

With the exponential growth in mobile data traffic taking place currently and projected into the future, mobile operators need cost effective ways to manage the load of their networks. Traditionally, this has been achieved by offloading mobile traffic onto Wi-Fi networks due to their low cost and increasingly ubiquitous deployment. Recently, LTE operating in the unlicensed spectrum has drawn significant interests from mobile operators due to the availability of the unlicensed spectrum. Using this technology, the unlicensed spectrum is directly utilized by LTE without the need to offload traffic to an alternative radio access technology such as Wi-Fi. However, the deployment of LTE networks in the unlicensed band poses significant challenges to the performance of current and future Wi-Fi networks. We discuss the LTE and Wi-Fi coexistence challenges and present analysis on performance degradation of the Wi-Fi networks at the presence of LTE. [ABSTRACT FROM AUTHOR]

Chromosomal and karyotype parameters and genome size were examined in 22 Iranian populations of nine different Tulipa species, using squash technique and 1 % (w/v) aceto-orcein stain. Flow cytometric studies were performed using PI staining method and Vicia faba cv. Inovec (2C DNA = 26.9 pg) as a reference standard. Most species were diploid (2 n = 2 x = 24), having three chromosome types ('m', 'sm', 'st'). The chromosome length (TL) varied from 6.4 μm (S2) to 12.90 μm (S3). Total chromosome volume (TCV) ranged from 32.9 μm (S2) to 66.0 μm (S8). Statistical analyses confirmed more intraspecific chromosomal and genome size variations than interspecific. S1E2, S2E1 and S5E2, with the highest intrachromosomal ( M) and relatively high interchromosomal asymmetry (CV), indicated higher asymmetry in the karyotype. The genome size in Tulipa species of Iran is being reported for the fist time. The mean 2C DNA was 54.52 pg, and ranged from 77.40 in S6E2 to 31.51 pg in S9E2. Significant positive correlations were found between 2C DNA and either TL or TCV. [ABSTRACT FROM AUTHOR]

Five species (14 ecotypes) belonging to three subgenera of ornamental-medicinal Iranian Fritillaria plant were chromosomally and karyotypically assessed, using squash technique and 1 % (w/v) aceto-orcein stain. All species were diploid (2 n = 2 x = 24) having mean chromosome length of 16.8 μm (14.2-18.6 μm). The satellites varied in number (1-4 pairs) and in size (1.27-3.01 μm): mostly locating on long arms. Four chromosome types ('m', 'sm', 'st', 'T') formed 11 different karyotypic formulas: the latter is being reported for the first time in some ecotypes in either S1 or S4. Nine chromosomal parameters were calculated. ANOVA verified intra- and inter-specific chromosomal variation in examined Iranian Fritillaria species. Twelve different methods were used to assess the degree of karyotype asymmetry. Among those, one qualitative (Stebbins classification) and seven quantitative (TF %, CV, DI, AsK %, A2, Rec, CG %) parameters verified that S2 and S5 species were recognized as having the most asymmetrical and symmetrical karyotypes, respectively. [ABSTRACT FROM AUTHOR]

• Effects of light intensity and AgNPs on shoot proliferation were evaluated in Phalaenopsis in vitro cultures. • Low light intensity (40 µmol−2 s−1) enhances shoot proliferation. • 5 µM of silver nanoparticles are suitable for increase the shoot quality. • The biochemical quality of regenerants is higher under high light intensity and high level of silver nanoparticles (AgNPs). This experiment was designed to improve shoot proliferation by optimizing light intensity and reducing the potential effects of ethylene such as explant yellowing, unexpanded leaf and narrow shoots. For this purpose, shoot tips as explants were cultured in to the Murashige and Skoog medium with major salts at half‐strength supplemented with silver nanoparticles concentrations (0, 5, 10, 20, 40 µM AgNPs) which were then exposed to three different light intensities (40, 80, 160 µmol m−2 s−1) for a period of three months. Morphological (leaf number, dry and fresh weight of regenerants), biochemical and oxidant/antioxidant responses of regenerants were quantified. According to the results, low light intensity (40 µmol m−2 s−1) stimulated the shoot proliferation of Phalaenopsis and the effects of 5 µM AgNPs on shoot number while showing the maximum fresh and dry weight. It was also observed that chlorophyll, carbohydrate and protein content, enzymatic activity (superoxide dismutase and catalase), H 2 O 2 generation, medium browning and phenolics content improve with higher light intensities (80 and 100 µmol m−2 s−1). Higher AgNP concentrations reduced shoot proliferation, dry weight, and soluble proteins. The most effective combinatorial treatment for the shoot proliferation stage of Phalaenopsis was determined to be 5 µM AgNPs and 40 µmol m−2 s−1. [ABSTRACT FROM AUTHOR]

Abstract: The electrochemical performance and carbon deposition on palladium catalyst promoted Ni/Gd0.1C0.9O1.95 (Ni/GDC) anode in methane and alcohol fuels like methanol and ethanol are investigated at open circuit potential and under dc bias using electrochemical impedance spectroscopy technique. Presence of Pd nanoparticle catalyst significantly promotes the electrocatalytic activity of Ni/GDC for the electrooxidation reaction in methane and in particularly in methanol and ethanol fuels. For instance, in the case of methanol oxidation reaction, there is clear separation of the impedance arcs at high and low frequencies and activation energy for the reaction is reduced by ∼33% on a 0.15 mg cm−2 PdO impregnated or infiltrated Ni/GDC anode. The transitional impedance response study when the inlet gas is switched from hydrogen to methane or alcohol fuels indicates that the oxidation reaction in methane and alcohol fuels is most likely dominated by adsorption, dissociation and diffusion steps of the reaction. Carbon deposition is also observed on Pd-infiltrated Ni/GDC in methanol and ethanol, but different from that observed in methane, there is no filament carbon fibers formation on the Pd-impregnated Ni/GDC surface in methanol fuel. [Copyright &y& Elsevier]

Abstract: A new severe plastic deformation (SPD) technique entitled PTCAP is proposed to be suitable for deforming cylindrical tubes to extremely large strains. The tube constrained between mandrel and die is pressed by a first punch into a tubular angular channel with two shear zones and the diameter of the tube is increased and then pressed back to the initial dimension by the second punch. This process was applied to a commercially pure copper and a significant grain refinement resulted to a mean grain size of 150–300nm was achieved even after a single pass PTCAP. Finite element (FE) results showed that the equivalent plastic strain of about 3±0.05 could be achieved at the end of the second cycle of PTCAP while it is about 3±0.4 at the end of the recently developed TCAP process. So, there is excellent strain homogeneity through the length and thickness of the PTCAP processed tube. Also, from the numerical results it was obtained that 57% lower loads are required for the PTCAP compared to TCAP. So, this new SPD process has two important advantages of excellent strain homogeneity and requiring a lower load. [Copyright &y& Elsevier]

Abstract: The effect of catalyst loading, operation temperature and co-infiltration of the palladium-based catalysts on the performance and stability of La0.8Sr0.2MnO3 (LSM) cathode of solid oxide fuel cells (SOFCs) is investigated. The result shows that adding a small amount of Pd catalyst (0.08mgcm−2) has a remarkable effect on the reduction of overpotential of LSM cathodes and high palladium loading is detrimental to the electrochemical activity of LSM cathodes. The performance and stability of the Pd-impregnated LSM cathodes can be enhanced significantly by co-infiltration of palladium with either 20 mol% of silver or 5 mol% of cobalt. Increased stability of the co-infiltrated catalyst materials is probably related to the enhanced resistance of the co-impregnated Pd0.95Co0.05 and Pd0.8Ag0.2 nanoparticles against agglomeration and sintering at SOFC operation temperatures. The results indicate the co-impregnation is effective not only to enhance the electrochemical activity but also to improve the stability of LSM cathodes for the O2 reduction reaction of SOFCs. [Copyright &y& Elsevier]

Abstract: La0.7Ca0.3Cr0.5Mn0.5O2.6/Gd-doped ceria (LCCM)/GDC composite oxides are developed as anodes for the hydrogen and methane oxidation reactions of solid oxide fuel cells (SOFCs). The composite anodes are sintered in temperatures range from 1150 to 1350°C and the lowest ohmic and polarization resistances of the cells are obtained on the anodes sintered at 1300°C. Electrode polarization resistance or area specific resistance (ASR) of the LCCM/GDC anode is 0.47Ωcm2 for the hydrogen oxidation reaction and ~2.2Ωcm2 for the methane oxidation reaction at 850°C. Addition of the Pd nanoparticles via a wet impregnation to the LCCM/GDC anodes decreases the ASR substantially to 0.15 and 0.23Ω cm2 for the hydrogen and methane oxidation reaction at 850°C, respectively. The reduction of the ASR is more pronounced for the methane oxidation reaction. The results indicate that the addition of Pd nanoparticles mainly affects the electrode process associated with the low frequencies, revealing the significant promotion effect of the impregnated Pd catalyst for the dissociation and diffusion processes of the hydrogen and methane oxidation reactions. The Pd-Impregnated LCCM/GDC composite anodes show a good stability in H2 and CH4 under conditions studied. [ABSTRACT FROM AUTHOR]

Introduction: Loss of the penis can have a devastating effect on the lives of sufferers with significant psychogenic implications. Penile reconstruction or phallus construction poses a difficult challenge and a demanding problem to the urologists and plastic surgeons. Different techniques have been used for construction of a total penis and reconstruction of severely injured penis. The objective of this review was to determine the efficacy, advantages and disadvantages of the most popular penile reconstruction (PR) and phallus construction techniques. Materials and Methods: We searched without language restriction MEDLINE, Pre-MEDLINE EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from January 1960 to January 2009. In addition, we searched the citation lists of relevant articles and book chapters. Studies evaluating the functional and cosmetic results of different techniques of total phallus construction (TPC) and penile reconstruction (PR) were identified. Two authors independently evaluated studies for selection, study quality, and extracted data. The primary outcome was creation of a sensate and cosmetically acceptable phallus. The secondary outcomes were competent neourethra that allows voiding in comfortable position, sexual intercourse, and the rate of complications. Results: One hundred and forty-six studies with a total of 1 622 patients were included in this review. Conclusion: Data from the available studies are insufficient to recommend any technique for TPC or PR. In the absence of evidence to support any method, the review authors recommend the one-stage TPC or PR. Further studies are warranted, preferably multi-centered studies. [ABSTRACT FROM AUTHOR]

Abstract: Forty landraces of Damask rose were collected from 28 provinces (13 origin sites) in Iran and evaluated to determine the diversity among them. The investigated characters were: flower weight, flower diameter, peduncle length, number of petals, number of stamens and oil content. Pearson''s coefficients showed that number of petals was positively correlated with flower weight (r =0.642) and number of stamens (r =0.630), while its correlation with peduncle length was negative (r =−0.53). A negative correlation was obtained between oil content and number of stamens (r =−0.60) which is useful for indirect selection of landraces with low number of stamens and therefore high amount of oil content. Cluster analysis based on five botanical characters and oil content separated the origin site 12, which included Guilan, Mazandaran and Golestan provinces with a specific climate condition of temperate humid, from other origin sites. This distinctiveness was already confirmed by the bi-plot of the principal components. The distribution of Damask rose landraces provided useful information for the future collection and for the genetic resource management in these origin sites. [Copyright &y& Elsevier]

Background: Damask roses (Rosa damascena Mill.) are mainly used for essential oil production. Previous studies have indicated that all production material in Bulgaria and Turkey consists of only one genotype. Nine polymorphic microsatellite markers were used to analyze the genetic diversity of 40 accessions of R. damascena collected across major and minor rose oil production areas in Iran. Results: All microsatellite markers showed a high level of polymorphism (5-15 alleles per microsatellite marker, with an average of 9.11 alleles per locus). Cluster analysis of genetic similarities revealed that these microsatellites identified a total of nine different genotypes. The genotype from Isfahan province, which is the major production area, was by far the most common genotype (27/40 accessions). It was identical to the Bulgarian genotype. Other genotypes (each represented by 1-4 accessions) were collected from minor production areas in several provinces, notably in the mountainous Northwest of Iran. Conclusion: This is the first study that uncovered genetic diversity within Damask rose. Our results will guide new collection activities to establish larger collections and manage the Iranian Damask rose genetic resources. The genotypes identified here may be directly useful for breeding. [ABSTRACT FROM AUTHOR]

Solid Oxide Cells (SOC), as a key energy-conversion technology, require sintering at temperatures exceeding 1200 °C, which tend to coarsen the structure of the fuel electrode. Nanostructured electrodes with high surface areas can help to decrease the electrode resistance and facilitate the operation of the SOC stacks at low temperatures with current collectors made from cheaper steel types. In this paper, we demonstrate and carefully evaluate a novel low-temperature manufacturing method for nanostructured Strontium Iron Molybdenum Oxide (SFM)/Gadolinium Doped Ceria (CGO) composite electrodes. The composite electrodes are applied on both sides of a Zr-based electrolyte with CGO barrier layers and sintered at 800 °C for 3 h in a 5% H 2 /N 2 atmosphere. The preparation parameters, thermal behavior, and electrode microstructure are studied to improve electrochemical performance. Based on the fitting of Nyquist plots, the electrochemical performance is mainly limited by two reactions in series at low frequency, in the 0.08–1 Hz and 1–50 Hz ranges. The electrode polarization resistance is almost constant at 1.24 Ω cm2 for 110 h at 750 °C in 60 vol% CO/CO 2. Unlabelled Image • A crack-free SFM/CGO composite fuel electrode prepared at 800 °C without formation of the SrZrO 3 insulator phase. • The electrochemical behavior obtained in CO/CO 2 and H 2 with 3 to 50 vol% H 2 O. • The relatively small polarization resistance makes it a candidate for substitution of the state-of-art Ni/YSZ electrode. • The quite dense and thin CGO barrier layer is applied via Radio-frequency magnetron sputtering. [ABSTRACT FROM AUTHOR]

Mixed ionic-electronic conductor LSCF is a popular cathode material for intermediate to low temperature solid oxide fuel cells; nevertheless, there are concerns about its surface-limited oxygen reduction reaction. In this work, Ruddlesden-Popper-structured La 2 NiO 4+δ (LNO) nanoparticles are introduced onto the surface of (La 0.6 Sr 0.4) 0.995 Co 0.2 Fe 0.8 O 3-δ (LSCF) cathode and the electrode performance is examined by means of electrochemical impedance spectroscopy (EIS) in the temperature range of 550–750 °C. Impedance spectra analysis shows that an 81% reduction in polarization resistance can be achieved by infiltration of LNO nanoparticles. The distribution of relaxation times (DRT) technique is used to gain insights on the physicochemical properties of the system under study. Obtained results reveal that by correlating oxygen surface exchange, bulk diffusivity, ionic conduction, and particle size of nano-structured LNO with the electronic and ionic conductivity of LSCF, the electrochemical behavior of the cathodes is improved. [ABSTRACT FROM AUTHOR]

• Facile route was developed to produce nanostructured LiFePO 4 olivine phase. • Medium milling energy decreased the formation temperature of LiFePO 4 well below 500 °C. • Activated carbon coating improved the capacity, rate capability and stability of battery. Nanostructured olivine LiFePO 4 was successfully synthesized by mechanical activation of powder obtained by co-precipitation. The effects of mechanical activation energy, calcination temperature and carbon coating on the LiFePO 4 characteristics were investigated. X-ray diffraction results revealed that mechanical activation has facilitated the formation of pure, fully crystallized and nano-structured LiFePO 4. Scanning electron microscope observations showed that the average particle size of LiFePO 4 powder is approximately 70 nm. Fourier transform infrared spectra analysis revealed the existence of no extra peak in the carbon coated LiFePO 4 samples compared to the pure one. Raman spectra demonstrated high quality of the obtained carbon layer with sp2/sp3 ratio of about 0.9 which proves the existence of highly conductive graphite like carbon in the cathode materials. Electrochemical analyses showed superior properties in the fields of capacity (163 mA h g−1 at 0.1C), rate capability, and battery stability over 50 cycles for mechanically activated LiFePO 4 /C cathode materials. [ABSTRACT FROM AUTHOR]

As the solid oxide cells (SOCs) are becoming durable, their air electrode materials require investigation for their tolerance against chromium (Cr) poisoning. Herein, La 2 NiO 4±δ (LNO), a highly electroactive and nucleation agent-free material, is infiltrated into the (La,Sr)MnO 3-δ (LSM) backbone to diagnose its' influence on the Cr-poisoning of LSM. While the non-impregnated LSM's degrades by Cr contaminant, LNO-infiltrated LSM (LSM.LNO) shows less sensitivity to Cr presence specifically during the electrolysis mode. LNO's presence inhibits the formation of detrimental phases at the electrode/electrolyte interface during the anodic polarization in Cr-containing ambient. Moreover, surface promotion by LNO nanoparticles reduces, but not inhibits, the formation of undesirable phases during the cathodic polarization in the Cr presence. According to the electrodes' overpotential trends, the electrochemical impedance spectroscopy (EIS) responses in addition to the distribution of the relaxation times (DRT) analysis, the presence of Cr alters the LSM.LNO's electrochemical characteristics via reacting with the nanoparticles. As the XRD analysis proves, LaCrO 3 formation on the LNO nanoparticles' surface gradually decays the LSM.LNO's cathodic performance. However, LNO's higher activity for oxygen evolution than oxygen reduction reaction accompanied by slower LNO/Cr reaction kinetics during anodic polarization improve and stabilize the LSM.LNO's anodic performance in Cr-containing environment. [Display omitted] • LNO impregnation improved LSM's ORR and OER performance. • LaCrO 3 formation was detected after LNO/Cr reaction. • LSM.LNO anode showed a stable behavior against Cr-poisoning. • Gradual formation of LaCrO 3 continuously impeded the ORR activity of the LSM.LNO cathode. • Detrimental phase formation was totally inhibited in the LSM.LNO anode. [ABSTRACT FROM AUTHOR]

In this article, we report the effects of slurry formulation and sintering conditions on the microstructure and permeability of porous titania sheets prepared by tape casting. It was found that solid concentration and binder content in the titania slurry play a vital role in the porosity and microstructure of the sintered titania sheets. Solid concentration and binder content were optimized based on the green tape quality and open porosity of the sintered titania sheets. The optimum solid concentration with the lowest surface roughness was obtained at 0.61 g/cm3. The effects of temperature and sintering time on the open porosity and crystal structure of the final product were also investigated. Increasing the sintering temperature from 1000 to 1100 °C resulted in increasing the pore size from 170 to 264 nm and decreasing the open porosity. Finally, water permeability of the porous titania sheets was studied to evaluate the permeation flux and maximum operating pressure. The results revealed that the permeability of the porous titania sheet is increased not only by increasing the open porosity but also by increasing the pore size. [ABSTRACT FROM AUTHOR]

Metal-air rechargeable batteries are being studied as an alternative to lithium-ion batteries. MnCo 2 O 4 as a ternary mixed metal oxide appeared as a promising oxygen electrocatalyst in metal-air batteries due to relatively high electrocatalytic activity and electronic conductivity. The effects of surface facets and calcination temperature on the electrochemical properties of MnCo 2 O 4 in zinc-air batteries are investigated experimentally and theoretically. The results show that by increasing calcination temperature, the surface facet is changing from the high index {112} to the low index {110}. Concurrently, the oxygen vacancy concentration rises with calcination temperature. Electrochemical results and first principle calculations indicate that the oxygen-deficient {110} facet has superior electrochemical activity over the {112} facet in terms of oxygen evolution reaction and oxygen reduction reaction. These results are essential for designing high performance spinel structured electrocatalyst materials. [Display omitted] [ABSTRACT FROM AUTHOR]

A retraction to the article "Accumulative Radial-Forward Extrusion (ARFE) processing as a novel severe plastic deformation technique" is presented.

Tuberose volatile components were evaluated at four developmental stages of flowers extracted by Hydrodistillation Extraction (HE), Solvent-Assisted Hydrodistillation Extraction (SAHE), Accelerated Organic Solvent Extraction (AOSE) and Organic Solvent Extraction (OSE). Among the total number of 37 compounds, benzenoids such as benzyl benzoate via AOSE and OSE seemed to have the highest values at Fully Opened stage (FO). In addition, FO showed the highest total amount of sesquiterpenoids extracted by all tested methods. Half-opened stage (HO) had the highest values of monoterpenoids such as 1,8-cineole in all methods of extraction, and benzenoids such as methyl benzoate from SAHE. Unopened bud (UO) and Nearly Slight Opened bud (NSO) stages showed the least amount of volatile compounds. Although OSE is treated as a traditional preparative extractive technique for tuberose oil, SAHE and AOSE could be useful for rapid extraction of preferable compound and the qualitative analysis of volatile components at analytical level. [ABSTRACT FROM AUTHOR]

[Display omitted] • The equivalent circuit of LR Ω (QR H)G was proposed based on the EIS response and DRT analysis of SFM/GDC cathode. • The LF part of EIS were related to the Gerischer response of SFM/GDC composite electrode. • Pd infiltration reduced the R G by 48% and 10% at 650 °C and 800 °C, respectively. • Surface exchange kinetics of SFM/GDC air electrode needs enhancement at intermediate temperatures. Employing potent advanced materials to perform as the cathode of SOFC requires a profound investigation on the material's electrochemical response within the oxygen reduction reaction. Accordingly, in this research, electrochemical characteristics of Sr 2 Fe 1.5 Mo 0.5 O 6-δ /Gd 0.1 Ce 0.9 O 1.5 (SFM/GDC) air electrode was studied using electrochemical impedance spectroscopy (EIS) and distribution of relaxation time (DRT) technique. SFM/GDC composite electrode sintered at 1050 °C shows the lowest polarization resistance of 0.23 Ω.cm2 at 800 °C. Three DRT peaks determined, and an LR Ω (QR H)G equivalent circuit is proposed for the EIS response, in which the Gerischer element was related to the low-frequency part. Two of the peaks indicated by DRT were associated to the Gerischer response, which reveals simultaneous occurrence of oxygen surface reaction and diffusion sub-processes during ORR. By temperature rising from 650 °C to 800 °C, Gerischer resistance (R G) reduces by 91%. Introduction of Pd nanoparticles into the electrode reduces the R G by 48% and 10% at 650 °C and 800 °C, respectively. The results demonstrate that at the intermediate temperature range, the SFM/GDC composite electrode requires improvement by surface decoration due to its insufficient surface exchange kinetics; however, significantly improved surface exchange kinetics is observed at higher temperature range without any surface modification. [ABSTRACT FROM AUTHOR]

The mechanism of non-stoichiometric MnCo 2 O 4+δ to stoichiometric MnCo 2 O 4 structural transformation in the calcination temperature range of 350–650 °C and its morphology evolution from nanoplates with {112} facets to quasi nanoplates with {110} facets in the preferential orientation of [220] direction is investigated in detail and confirmed using XPS, HRTEM, TGA, and XRD analysis. By having a profound understanding of this mechanism, MnCo 2 O 4 with a well-controlled structure and morphology was synthesized via co-precipitation as the anode for Li-ion batteries to overcome the capacity fading issue. Moreover, the anode microstructure was optimized based on the correlation between Li+ storage, electrode durability, and interfacial resistance through the electrochemical response of electrode components, including MnCo 2 O 4 , carbon black, and binder. The optimum electrode exhibited a high initial discharge capacity of 2063 mAh g−1 at 400 mA g−1, excellent rate capability (807 mAh g−1 at 1000 mA g−1), and outstanding cycling performance (709 mAh g−1 at 400 mA g−1 after 150 cycles). These are attributed to the balance between the high surface area and robust architecture of MnCo 2 O 4 , and the stability, conductivity, and porosity of the electrode. [Display omitted] • Phase studies show that increasing the temperature to 650 °C resulted in the evacuation of excess oxygen in MnCo 2 O 4+δ. • By increasing the temperature, {112} facets alter to {110} facets in the preferential orientation of [220] direction. • The optimized electrode exhibited a stable reversible capacity of 709.5 mAh g−1 over 150 cycles at 400 mA g−1. [ABSTRACT FROM AUTHOR]

Lovastatin is a blood cholesterol-lowering agent and is produced as a secondary metabolite by Aspergillus terreus. Microbial production of this drug is carried out in solid-state or submerged culture, and due to difficulties of controlling the procedure parameters in solid-state method, the submerged method is conventional for industrial production. Although the submerged method is widely used, but this method damages the morphology of fungus due to shear stress caused by stirring. Since the morphology of fungus is a key factor in lovastatin production, using a bioreactor that causes the least damage to it, can improve the lovastatin production. In this paper, for the first time, it has been shown that the membrane gradostat bioreactor is suitable for lovastatin production, using A. terreus, due to providing suitable environmental conditions, therefore, it can be implemented as an alternative method for lovastatin production. Furthermore, it was found that implementing two-stage feeding, using different ratios of Carbon to Nitrogen in the culture medium, makes the lovastatin production to be 5 times more than one-stage feeding. Finally, it is shown that adding Zinc and Magnesium at the second stage further increases lovastatin production by 18%. [ABSTRACT FROM AUTHOR]

In the present study, the effect of different aluminum and vanadium precursors on the formation and physical properties of the V 2 AlC MAX phase were studied. The results showed that the synthesis of V 2 AlC is more favorable by elemental precursors than carbide precursors, and at least the presence of one metallic element is essential to accelerate the phase formation. The highest electrical conductivity (254 ± 12 Sm − 1) was for the sample with fine powders of VC and aluminum as precursors. The purest sample (76.2% wt. V 2 AlC) had metallic elemental precursors for both vanadium and aluminum sources and showed electrical conductivity of 188 ± 9 Sm − 1. The results showed that the specific surface area had no direct effect on the electrical conductivity because its increase can improve the electrical contacts between the powder particles and on the other side, it increases the surface resistivity. [Display omitted] • The V 2 AlC MAX phases were synthesized successfully using different precursors. • The presence of at least one metallic element is essential to form the V 2 AlC phase. • The surface area has a "double-edged sword" effect on electrical conductivity. [ABSTRACT FROM AUTHOR]

This study develops a comprehensive vibrational analysis of rotating nanobeams on visco-elastic foundations with thermal effects based on the modified couple stress and Eringen's nonlocal elasticity theories. This approach accurately simulates the nonlocal stress and size effects. Higher-order shear deformation beam theory and the generalized differential quadrature method are used to obtain the numerical results. The effects of nonlocal parameters, length scale, Winkler–Pasternak coefficients, thermal gradient, slenderness ratios, rotating velocity, and viscoelastic coefficient are demonstrated and discussed in detail. Mode switching and the importance of the correct choice of theory and associated size effect parameters are highlighted. [ABSTRACT FROM AUTHOR]