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In the present paper, magnetic Barkhausen noise (MBN) measurements have been carried out to evaluate the hardness and ferrite grain size of API X70 steel. All samples were austenitized at 900–1200 °C for 0.5 h followed by air-cooling identically to develop different ferrite grain size. The microstructure examinations were determined by Scanning Electron Microscope (SEM). The average ferrite grain size in each sample was estimated using ImageJ open-source software. Hardness measurements were performed using durometer device. Measurements of MBN were conducted using MikroMach (Micromagnetic Materials Characterization) system. The microstructure observation shows that the increase in the austenization temperature (AUT) causes an increase in the ferrite grain size as well as their change in shape from polygonal to acicular. The results of mechanical tests showed that the increase in the austenization temperature leads to an increase in the hardness of the X70 steel. Actually, MBN method can be used to evaluate the changes in hardness and ferrite grain size in ferromagnetic materials. The sample with the lowest austenitic temperature has the highest Barkhausen noise amplitude (BNA); in contrast, the sample which contains the highest austenitic temperature has the lowest BNA; furthermore, when the austenization temperatures increases, the signal of the coercive field Hc shifts to the higher values of magnetic field. Additionally, BNA decreases, and Hc increases whenever hardness and ferrite grain size increases. In this way, a good correlation was found between MBN parameters, ferrite grain size, and hardness values. The realized experimental setup can be used for online evaluate steel microstructures and quality control of ferromagnetic materials in some industrial applications. [ABSTRACT FROM AUTHOR]

In recent years, Pd/CeO2 materials have proven to be effective catalysts for the total oxidation of methane. In this work, three different synthesis routes were used to prepare high specific surface area supports, consisting of pure CeO2 and 10 at% Pr‐doped ceria (Ce90Pr10). Nano‐structured spheres were obtained with a microwave‐assisted synthesis, dumbbell‐like particles were produced through a urea‐based hydrothermal method, and ordered mesoporous oxides were prepared by using SBA‐15 as hard‐template. The six materials were then impregnated with 2 wt% Pd, calcined at 500 °C, and comprehensively characterized. All the samples retained their high surface area after impregnation (75–110 m2 g−1), allowing a good dispersion of palladium. No significant structural or morphological differences were observed upon Pr doping, but a higher Pd oxidation state was induced by Pr‐doped supports. However, all Pd/CeO2 and Pd/Ce90Pr10 catalysts exhibited similar activity for dry methane oxidation below 500 °C, regardless of the synthesis technique and of the Pr presence: they all achieved almost complete CH4 oxidation at 400 °C, showing a really remarkable improvement with respect to analogous low surface area supports. A promoting role of Pr was instead noticed in wet conditions, thanks to its ability to counteract water‐induced deactivation phenomena. [ABSTRACT FROM AUTHOR]

The Paris COP21 held on December 2015 represented a step forward global GHG emission reduction: this led to intensify research efforts in renewables, including biofuels and bioliquids. However, addressing sustainable biofuels and bioliquid routes and value chains which can limit or reverse the ILUC (indirect land-use change effect) is of paramount importance. Given this background condition, the present study targets the analysis and modelling a new integrated biomass conversion pathway to produce renewable advanced fuels, enabling the issue of indirect land-use change (ILUC) of biofuels to be tackled. The bioenergy chain under investigation integrates the decentralized production of biogas through anaerobic digestion and its upgrading to biomethane, followed by a centralized conversion to liquid transport fuels, involving methane reforming into syngas, Fischer–Tropsch (FT) synthesis, and methanol synthesis. The methodology adopted in this work stem from extensive literature review of suitable bio/thermo-chemical conversion technologies and their process modelling using a commercial flow-diagram simulation software is carried out. The major significance of the study is to understand the different modelling approaches, to allow the estimation of process yields and mass/energy balances: in such a way, this work aims at providing guidance to process modellers targeting qualitative and quantitative assessments of biomass to biofuels process routes. Beyond FT products, additional process pathways have been also explored, such as MeOH synthesis from captured CO2 and direct methane to methanol synthesis (DMTM). The analysis demonstrated that it is possible to model such innovative integrated processes through the selected simulation tool. However, research is still needed as regards the DMTM process, where studies about modelling this route through the same tool have not been yet identified in the literature. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to investigate the efficacy of teeth flux sensors in detecting, locating and assessing the severity of short-circuit faults in the stator windings of induction machines. Design/methodology/approach: The experimental study involves inducing short-circuit winding turn variations on the induction machine's stator and continuously measuring the RMS values across teeth flux sensors. Two crucial steps are taken for machine diagnosis: measurements under load operating conditions for fault detection and measurements under no-load conditions to determine fault location and severity. Findings: The experimental results demonstrate that the proposed approach using teeth flux sensors is reliable and effective in detecting, locating and evaluating the severity of stator winding faults. Research limitations/implications: While this study focuses on short-circuit faults, future research could explore other fault types and alternative sensor configurations to enhance the comprehensiveness of fault diagnosis. Practical implications: The methodology outlined in this paper holds the potential to significantly reduce maintenance time and costs for induction machines, leading to substantial savings for companies. Originality/value: This research contributes to the field by presenting an innovative approach that uses teeth flux sensors for a comprehensive fault diagnosis in induction machines. The originality lies in the effectiveness of this approach in providing reliable fault detection, location and severity evaluation. [ABSTRACT FROM AUTHOR]

Fast estimation is a critical feature of the proposed modeling approach as a "forward" fast solver that has a key role in solving the "inverse" problem involved in crack sizing, especially for real‐time applications. To this end, two different inversion methods have been proposed to estimate the crack depth. The first one uses an interpolation model of the 3D direct model simulation data. The second approach is based on artificial neural networks (ANN). In this article, the rotating uniform eddy current (RUEC) probe is used to detect the normal magnetic component Bz which is defined as the characteristic signal for reconstructing the crack length and depth concurrently. Using the first approach, The Bz characteristic 3D surface is presented, and this can be modeled by a fitted polynomial interpolation equation. Thus, the crack depth can be inverted using this equation referring to the experimental or simulated Bz signal and the crack length. The ANN is outlined to determine the crack depth based on the simulated Bz signature. The move from the first inversion method to the second was flexible and useful, in which the interpolation model is used as a defect signal generator for fast building of a large and efficient database for ANN training. Both of the proposed methods proved the objectivity and accuracy of the inversion results and offered more robust engineering support for automated NDT, reducing production time and increasing productivity. [ABSTRACT FROM AUTHOR]

The treatment of dairy industry effluents poses a significant challenge from the environmental point of view because of its high organic load. In this work, the aqueous phase reforming of lactose was investigated as a representative model compound for the production of renewable hydrogen. The tests were conducted using two different scenarios: the first one is referred to as direct aqueous phase reforming (APR); the second one proposed a pre-hydrogenation step, followed by APR. The implementation of this reactive pretreatment allowed for minimizing the solid by-product formation with respect to the direct APR, where most of the initial carbon ended up as solid residue. The pre-hydrogenation was investigated in the range of 180–220 °C, using Ru-based catalysts. In the best scenario (using 5% Ru/C), the carbon to solid was reduced by 95%, and up to 70% of the initial carbon was converted into gaseous compounds, hence contributing to the removal of the organic content of the wastewater while producing an energy carrier. Moreover, the hydrogen selectivity increased up to 70% (with respect to 2.5% for direct APR), thanks to hindering homogeneous reaction pathways that do not lead to hydrogen production. Finally, an energetic analysis was conducted to assess the possibility of coupling the APR with the dairy industry and quantifying the percentage of energy which may be produced in situ to satisfy industrial duties. [ABSTRACT FROM AUTHOR]

The hydrothermal liquefaction (HTL) of biomass is a strategic process to convert wet and waste feedstocks into liquid biofuel. In this work, we investigated the hydrothermal liquefaction of glucose and glycine, alone and together, to mimic the composition of low-lipid content biomass. Experimental tests were performed in a batch setup in the temperature range of 200–350 °C. As the feeding composition and temperature changed, the distribution among the different phases (gas, solid, biocrude, and aqueous phase) and their compositions were evaluated through different analytical techniques (GC–MS, µ-GC, HPLC). Glucose–glycine showed strongly different interactions with reaction temperature: increased biocrude production at high temperature and increased solid production at low temperature, following a proportionally inverse trend. Biocrude, as well as all the other phases, was observed to be completely different according to the feedstock used. To study how their formation and mutual interactions were affected by the composition of the starting feedstock, consecutive reactions of the generated phases were innovatively carried out. The solid phase generated from glucose–glycine interaction at low temperatures was experimentally observed to be mostly converted into biocrude at high temperatures. Furthermore, no interaction phenomena between the different phases were observed with glucose–glycine, while with glucose alone the co-presence of the molecules in the different phases seemed to be the cause for the lowest biocrude yield at high temperatures. The results obtained in this work can provide new insights into the understanding of hydrothermal liquefaction of low-lipid biomass, pointing out synergetic phenomena among both the biomolecules and the resulting phases. [ABSTRACT FROM AUTHOR]

Hingrand, C, Olivier, N, Combes, A, Bensaid, S, and Daussin, FN. Power is more relevant than ascensional speed to determine metabolic demand at different gradient slopes during running. J Strength Cond Res 37(11): 2298-2301, 2023--Trail running is characterized by successive uphill and downhill running sessions. To prescribe training intensity, an assessment of maximal running capacity is required. This study compared 2 uphill incremental tests using the same ascensional speed increment to identify the influence of the slope gradient on performance. Ten subjects (8 men and 2 women) performed 3 incremental exercises on various slope (1%: IT01, 10%: IT10, and 25%: IT25), and the ascensional speed increment was similar between IT10 and IT25 (100 m·h21 every minute). Gas exchanges, heart rate, and power were monitored continuously during the tests. Similar V̇O2max levels were observed in the 3 conditions: 68.766.2 for IT01, 70.167.3 for IT10, and 67.667.0 for IT25. A greater maximal ascensional speed was reached in the IT25 (1760 6 190 vs. 1,330 6 106 for IT25 and IT10, respectively, p, 0.01). A significant relationship was observed between relative V̇O2 levels and relative power without any effect of slope. Power should be the parameter used for prescribing training intensity compared with ascensional speed in trail. [ABSTRACT FROM AUTHOR]

Purpose: Detecting the orientation of cracks is a major challenge in the development of eddy current nondestructive testing probes. Eddy current-based techniques are limited in their ability to detect cracks that are not perpendicular to induced current flows. This study aims to investigate the application of the rotating electromagnetic field method to detect arbitrary orientation defects in conductive nonferrous parts. This method significantly improves the detection of cracks of any orientation. Design/methodology/approach: A new rotating uniform eddy current (RUEC) probe is presented. Two exciting pairs consisting of similar square-shaped coils are arranged orthogonally at the same lifting point, thus avoiding further adjustment of the excitation system to generate a rotating electromagnetic field, eliminating any need for mechanical rotation and focusing this field with high density. A circular detection coil serving as a receiver is mounted in the middle of the excitation system. Findings: A simulation model of the rotating electromagnetic field system is performed to determine the rules and characteristics of the electromagnetic signal distribution in the defect area. Referring to the experimental results aimed to detect artificial cracks at arbitrary angles in underwater structures using the rotating alternating current field measurement (RACFM) system in Li et al. (2016), the model proposed in this paper is validated. Originality/value: CEDRAT FLUX 3D simulation results showed that the proposed probe can detect cracks with any orientation, maintaining the same sensitivity, which demonstrates its effectiveness. Furthermore, the proposed RUEC probe, associated with the exploitation procedure, allows us to provide a full characterization of the crack, namely, its length, depth and orientation in a one-pass scan, by analyzing the magnetic induction signal. [ABSTRACT FROM AUTHOR]

Lignin‐rich stream from lignocellulosic ethanol production was converted into biocrude by continuous hydrothermal liquefaction (HTL) while hydrogen was produced by aqueous phase reforming (APR) of the HTL aqueous by‐product. The effects of Na2CO3 and NaOH were investigated both in terms of processability of the feedstock as well as yield and composition of the obtained products. A maximum biocrude yield of 27 wt% was reached in the NaOH‐catalyzed runs. A relevant amount of dissolved phenolics were detected in the co‐produced aqueous phase (AP), and removed by liquid–liquid extraction using butyl acetate or diethyl ether, preserving the APR catalyst stability and reaching an hydrogen yield up to 146 mmol H2 L−1 AP. Preliminary mass balances integrating HTL and APR showed that the hydrogen provided by APR may account for up to 46% of the hydrogen amount theoretically required for upgrading the HTL biocrude, thus significantly improving the process performance and sustainability. [ABSTRACT FROM AUTHOR]

The direct hydrogenation of CO2 into dimethyl-ether (DME) has been studied in the presence of ferrierite-based CuZnZr hybrid catalysts. The samples were synthetized with three different techniques and two oxides/zeolite mass ratios. All the samples (calcined and spent) were properly characterized with different physico-chemical techniques for determining the textural and morphological nature of the catalytic surface. The experimental campaign was carried out in a fixed bed reactor at 2.5 MPa and stoichiometric H2/CO2 molar ratio, by varying both the reaction temperature (200–300 °C) and the spatial velocity (6.7–20.0 NL∙gcat−1∙h−1). Activity tests evidenced a superior activity of catalysts at a higher oxides/zeolite weight ratio, with a maximum DME yield as high as 4.5% (58.9 mgDME∙gcat−1∙h−1) exhibited by the sample prepared by gel-oxalate coprecipitation. At lower oxide/zeolite mass ratios, the catalysts prepared by impregnation and coprecipitation exhibited comparable DME productivity, whereas the physically mixed sample showed a high activity in CO2 hydrogenation but a low selectivity toward methanol and DME, ascribed to a minor synergy between the metal-oxide sites and the acid sites of the zeolite. Durability tests highlighted a progressive loss in activity with time on stream, mainly associated to the detrimental modifications under the adopted experimental conditions. [ABSTRACT FROM AUTHOR]

Transfer function and state-space model are two powerful complementary tools have been used to monitoring the physical system. These two ways can be very successful in giving a comprehensive analysis of electrical power transformer malfunctions. This paper proposes a novel robust approach nondestructive to diagnose short circuit (SC) faults by considering axial displacements (AD) in the transformer winding. Initially, elaboration a native autonomously tool to control the LCR meters through computing systems. This platform will control the impedance measurement by the instrument of the LCR meter through MATLAB software. Additionally, achieving estimation autonomously to all the parameters of the lumped equivalent model of the winding accurately using frequency response analysis signal morphology interpretation (FRASMI). On the other hand, obtaining a new representation of the state-space model of the lumped equivalent model of an isolated winding with SC fault between its turns to locate and assess its severity. Finally, the relationship between the model parameters and the resonance frequencies of the frequency response curve can provide an effective nondestructive diagnostic tool for all mechanical damages of winding (e.g., SC with AD) which have been implemented experimentally, in which a new physical index has been proposed making it possible to locate and assess the extent of these defects simultaneously. [ABSTRACT FROM AUTHOR]

In this study, a set of CuCeOx catalysts was prepared via the coprecipitation method using a Multi-Inlet Vortex Reactor: the Cu wt.% content is 5, 10, 20, 30 and 60. Moreover, pure CeO2 and CuO were synthesized for comparison purposes. The physico-chemical properties of this set of samples were investigated by complementary techniques, e.g., XRD, N2 physisorption at −196 °C, Scanning Electron Microscopy, XPS, FT-IR, Raman spectroscopy and H2-TPR. Then, the CuCeOx catalysts were tested for the CO and ethene oxidation reactions. As a whole, all the prepared samples presented good catalytic performances towards the CO oxidation reaction (1000 ppm CO, 10 vol.% O2/N2): the most promising catalyst was the 20%CuCeOx (complete CO conversion at 125 °C), which exhibited a long-term thermal stability. Similarly, the oxidative activity of the catalysts were evaluated using a gaseous mixture containing 500 ppm C2H4, 10 vol.% O2/N2. Accordingly, for the ethene oxidation reaction, the 20%CuCeOx catalyst evidenced the best catalytic properties. The elevated catalytic activity towards CO and ethene oxidation was mainly ascribed to synergistic interactions between CeO2 and CuO phases, as well as to the high amount of surface-chemisorbed oxygen species and structural defects. [ABSTRACT FROM AUTHOR]

In skeletal muscle, chronic oxygen depletion induces a disturbance leading to muscle atrophy. Mechanical stress (physical exercise) and nutritional supplement therapy are commonly used against loss of muscle mass and undernutrition in hypoxia, while oxygenation therapy is preferentially used to counteract muscle fatigue and exercise intolerance. However, the impact of oxygenation on skeletal muscle cells remains poorly understood, in particular on signalling pathways regulating protein balance. Thus, we investigated the effects of each separated treatment (mechanical stress, nutritional supplementation and oxygenation therapy) on intracellular pathways involved in protein synthesis and degradation that are imbalanced in skeletal muscle cells atrophy resulting from hypoxia. Myotubes under hypoxia were treated by electrical stimulation, amino acids supplement or oxygenation period. Signalling pathways involved in protein synthesis (PI3K-Akt-mTOR) and degradation (FoxO1 and FoxO3a) were investigated, so as autophagy, ubiquitin–proteasome system and myotube morphology. Electrical stimulation and oxygenation treatment resulted in higher myotube diameter, myogenic fusion index and myotubes density until 48 h post-treatment compared to untreated hypoxic myotubes. Both treatments also induced inhibition of FoxO3a and decreased activity of ubiquitin–proteasome system; however, their impact on protein synthesis pathway was specific for each one. Indeed, electrical stimulation impacted upstream proteins to mTOR (i.e., Akt) while oxygenation treatment activated downstream targets of mTOR (i.e., 4E-BP1 and P70S6K). In contrast, amino acid supplementation had very few effects on myotube morphology nor on protein homeostasis. This study demonstrated that electrical stimulation or oxygenation period are two effective treatments to fight against hypoxia-induced muscle atrophy, acting through different molecular adaptations. [ABSTRACT FROM AUTHOR]

In this paper we present a simple approach to compute quickly and accurately the global inductance of multilayer circular air coils with a wire of rectangular cross section. The case of the uniform current density distribution in the wire cross section is considered. The approach, implemented under GNU Octave, computes the inductance of the multilayer coil in three steps. First, the selfinductance of each coil turn is computed using the Maxwell's formula. Secondly, each wire section is subdivided into several negligible square or rectangular subsections to form a filiform turn, and then the mutual inductances between the turns are computed using Rosa's formula. The last step sums all obtained self-inductances and mutual inductances to deduce the global inductance of the multilayer coil. To verify the efficiency and accuracy of the proposed approach, the obtained equivalent inductance of each turn is compared to the computed one using finite element method implemented in FEMM open source. Furthermore, the global coil inductance is compared to the measured one. The proposed approach shows a good accuracy with a relative error less than 1% for all considered coils. [ABSTRACT FROM AUTHOR]

A set of cerium–manganese–copper oxide catalysts with various foreign metal contents was prepared via the solution combustion synthesis (SCS). The catalysts were characterized by complementary techniques such as N2 physisorption at − 196 °C, X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), H2-temperature-programmed reduction (H2-TPR), O2-temperature-programmed desorption (O2-TPD) and X-ray photoelectron spectroscopy (XPS). Their catalytic activity was tested towards the VOC oxidation using ethylene and propylene as probe molecules. As a whole, it has been observed that the Ce55Mn45 sample (Mn 45 at.%), containing MnOx clusters interacting with the ceria phase, was the most active catalyst for propylene oxidation, exhibiting a complete conversion at 250 °C. On the other hand, the ternary oxide catalyst (Ce55Mn22.5Cu22.5 with Mn = 22.5 at.% and Cu = 22.5 at.%) has exhibited the best results for the oxidation of ethylene. These findings suggest that the co-presence of different active phases on the catalytic surface may have a beneficial (multiplicative) role on the whole reactivity. Finally, the most active powder catalysts were wash-coated in a SiC monolith and tested in a bench-scale reactor. As a whole, the catalyzed monoliths performed the complete oxidation of either ethylene or propylene at lower temperatures (550 and 450 °C, respectively) than those required to thermally decompose these molecules. [ABSTRACT FROM AUTHOR]

A group of catalysts was developed with the purpose of enhancing the soot oxidation in the selective catalytic reduction on filter system, without negatively effecting the NOx conversion associated to NH3 oxidation. The impregnation with alkali metal of a series of supports, characterized by a lack of strong superficial acid sites, improved soot oxidation simultaneously preventing ammonia adsorption, thus its catalytic oxidation. Strong synergy was observed between a ZrO2–CeO2 support and potassium, decreasing the T50 of the soot conversion of 170 °C in loose contact. This catalyst was added to a Fe-ZSM5 selective catalytic reduction (SCR) catalyst without negative effect for the SCR activity. The complex interaction between the potassium-based soot oxidation catalyst and the SCR one was investigated. The soot–soot oxidation catalyst-SCR catalyst contact mode was found to be a key factor and the increased contact of the soot–soot oxidation catalyst is preferable. Such dual component catalyst system was demonstrated to be promising for simultaneous removal of NOx and soot on a single filter. [ABSTRACT FROM AUTHOR]

Hypoxia, occurring in several pathologies, has deleterious effects on skeletal muscle, in particular on protein homeostasis. Different induction methods of hypoxia are commonly used in cellular models to investigate the alterations of muscular function consecutive to hypoxic stress. However, a consensus is not clearly established concerning hypoxia induction methodology. Our aim was to compare oxygen deprivation with chemically induced hypoxia using cobalt chloride (CoCl2) or desferrioxamine (DFO) on C2C12 myotubes which were either cultured in hypoxia chamber at an oxygen level of 4% or treated with CoCl2 or DFO. For each method of hypoxia induction, we determined their impact on muscle cell morphology and on expression or activation status of key signaling proteins of synthesis and degradation pathways. The expression of HIF-1α increased whatever the method of hypoxia induction. Myotube diameter and protein content decreased exclusively for C2C12 myotubes submitted to physiological hypoxia (4% O2) or treated with CoCl2. Results were correlated with a hypophosphorylation of key proteins regulated synthesis pathway (Akt, GSK3-β and P70S6K). Similarly, the phosphorylation of FoxO1 decreased and the autophagy-related LC3-II was overexpressed with 4% O2 and CoCl2 conditions. Our results demonstrated that in vitro oxygen deprivation and the use of mimetic agent such as CoCl2, unlike DFO, induced similar responses on myotube morphology and atrophy/hypertrophy markers. Thus, physiological hypoxia or its artificial induction using CoCl2 can be used to understand finely the molecular changes in skeletal muscle cells and to evaluate new therapeutics for hypoxia-related muscle disorders. [ABSTRACT FROM AUTHOR]

In this work, ceria-based nanocatalysts mixed with copper and manganese were studied. All the catalysts were synthesized via the hydrothermal procedure. Four samples were prepared here denoted through the atomic ratios of the metals in the mixed oxide: Ce0.95Mn0.05, Ce0.95Cu0.05, Ce0.95Mn0.025Cu0.025 and CeO2. The samples were tested for the CO and soot oxidation reactions with different gas-phase oxygen concentrations (10, 1.0, 0.5 and 0.02 vol% O2). As a whole, the most promising catalysts for the CO oxidation reaction are the Ce0.95Cu0.05 and Ce0.95Mn0.025Cu0.025 samples. Indeed, the presence of Cu species in the solid enhances the surface redox mechanism for the CO oxidation. High vol% O2 values lead to competitive CO and O2 adsorption on the catalyst surface thus reducing the catalytic performances for binary and ternary oxides. On the other hand, the CO oxidation reaction over the CeO2 catalyst appears favored with 10 vol% O2. For the soot oxidation reaction, the most active catalyst (in terms of soot conversion %) is the CeO2 sample likely due to the unique feature of presenting well-defined and highly reactive nanocubic structures. Moreover, the presence of 10 vol% O2 in the mixture appears to be the best condition to oxidize the soot particles.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Generally, the thickness of thick metallic plates is measured by exploitation of some physical phenomenon outside of eddy currents which are naturally limited for thin plates with respect to the skin effect. Indeed, it is the capacitive or ultrasound sensors which are the commonly used for thick plates. This paper proposes an alternative for thickness evaluation of thick metallic plates using eddy currents. The measurement system consists mainly of two eddy current sensors, an impedance analyzer LCR-meter and a personnel computer equipped with the Labview software. The plate we want to measure its thick thickness is placed between the two sensors. The proposed measurement procedure is based on lift-offs evaluation of a bi-eddy current sensor. The system has been verified and validated with success using several thick aluminum plates. The realized experimental setup can be used for online thickness measurement in some industrial applications. [ABSTRACT FROM AUTHOR]

This research developed a comprehensive computer model for a lab-scale Slurry Bubble Column Reactor (SBCR) (0.1 m Dt and 2.5 m height) for Fischer–Tropsch (FT) synthesis under flexible operation of synthesis gas load flow rates. The variable loads of synthesis gas are set at 3.5, 5, 7.5 m3/h based on laboratory adjustments at three different operating temperatures (483, 493 and 503 K). A set of Partial Differential Equations (PDEs) in the form of mass transfer and chemical reaction are successfully coupled to predict the behavior of all the FT components in two phases (gas and liquid) over the reactor bed. In the gas phase, a single-bubble-class-diameter (SBCD) is adopted and the reduction of superficial gas velocity through the reactor length is incorporated into the model by the overall mass balance. Anderson Schulz Flory distribution is employed for reaction kinetics. The modeling results are in good agreement with experimental data. The results of dynamic modeling show that the steady state condition is attained within 10 min from start-up. Furthermore, they show that step-wise syngas flow rate does not have a detrimental influence on FT product selectivity and the dynamic modeling of the slurry reactor responds quite well to the load change conditions. [ABSTRACT FROM AUTHOR]

Ceria-based catalysts doped with manganese and copper were obtained via the hydrothermal synthesis. Four systems were synthesized: CeO (pure ceria), CeMn (Mn/Ce at. ratio = 1/19), CeCu (Cu/Ce at. ratio = 1/19) and CeMnCu (Mn/Cu/Ce at. ratio = 1/1/38). The catalytic activity of the prepared materials was tested for the CO and soot oxidations. Complementary techniques (XRD, N physisorption at − 196 °C, FESEM, XPS, Raman spectroscopy, CO-TPR and Soot-TPR) were performed to investigate their physico-chemical properties. The samples were characterized by nanocubes, in the case of CeO, and by nanopolyhedra for binary (CeMn and CeCu) and ternary oxides (CeMnCu). The CO-TPR analysis has confirmed that the reducibility follows the order: CeO < CeMn < CeMnCu < CeCu. A similar trend appears for the surface defective sites (Raman spectroscopy). These findings suggest the beneficial role of dopants in improving the structural defects and the surface reducibility of ceria. Both properties promote the CO oxidation activity. In fact, the CeCu was the most effective catalyst for the CO oxidation. The CeMn sample exhibited the best performance in soot oxidation. The following order was achieved: CeMnCu < CeCu < CeO ≈ CeMn, in agreement with the reduction profiles obtained by the Soot-TPR above 400 °C. Graphical Abstract: [ABSTRACT FROM AUTHOR]

Three Ce–Cu mixed oxides, namely Ce0.95Cu0.05, Ce0.6Cu0.4 and Ce0.15Cu0.85, along with pure CeO2 and CuO were characterized by in situ electrical conductivity measurements. Their electrical conductivity was studied as a function of temperature and oxygen partial pressure, and was followed with time during successive exposure to air, nitrogen and different gaseous mixtures containing propane as a VOC model molecule, under conditions close to those of their catalytic applications. CeO2 and CuO appeared to be n-type and p-type semiconductors, respectively, while the semiconducting behavior of the Ce–Cu mixed oxides depended on the oxide composition. The semiconductive and redox properties of the samples were correlated with their catalytic behavior in CO oxidation, ethene total oxidation and soot combustion. [ABSTRACT FROM AUTHOR]

In this work, several nanostructured ceria catalysts were prepared by means of a hydrothermal procedure, in which the synthesis conditions (i.e., temperature and pH values) were varied. CeO2 samples of different shapes and structural properties were obtained, namely cubes, rods, cube and nanorod mixtures, and other polyhedra. The prepared materials were tested using four probe catalytic reactions: CO oxidation, NO oxidation, NOx-free soot oxidation, and NOx-assisted soot oxidation. The physicochemical properties of the prepared catalysts were studied by means of complementary techniques (i.e., XRD, N2-physisorption at --196 °C, CO-TPR (temperature-programmed reduction), field emission scanning electron microscopy (FESEM), micro-Raman spectroscopy). The abundance of defects of the catalysts, measured through in-situ Raman spectroscopy at the typical temperatures of each catalytic process, was correlated to the CO and NO oxidation activity of the prepared catalysts, while the soot oxidation reaction (performed in loose conditions), which was hindered by a poor soot-catalyst contact, was found to be less sensitive to the observed structural defects. [ABSTRACT FROM AUTHOR]

This article presents an environmentally friendly approach for the conversion of rapeseed oil via supercritical ethanol condition, with and without the presence of a solid catalyst, to produce biodiesel. The experiment was conducted in a batch reactor at various temperatures, reaction times, and ethanol to oil molar ratios. The evolution of process was followed by high performance liquid chromatography to determine accurately and quickly the content of final reaction mixture in a single analysis. The results show that the highest biodiesel yields of 93% (with ZnO) and 88% (with CaO) were obtained after the reaction time of 60 min at a temperature of 270°C. This process has high potential in minimizing the production cost of biodiesel due to its simplicity and technical advantage. [ABSTRACT FROM AUTHOR]

In this work, we investigated a set of ceria-based catalysts prepared by the hydrothermal and solution combustion synthesis. For the first time to our knowledge, we synthesized nanocubes of ceria doped with zirconium and praseodymium. The catalysts were tested for the CO and soot oxidation reactions. These materials exhibited different surface reducibility, as measured by H2-TPR, CO-TPR and Soot-TPR, despite their comparable chemical compositions. As a whole, Soot-TPR appears a suitable characterization technique for the soot oxidation catalysts, whereas CO-TPR technique allows to better discriminate among the CO oxidation activities. Praseodymium contributes positively toward the soot oxidation. On the other hand, it has an adverse effect on the CO oxidation over the same catalysts, as compared to pure ceria. The incorporation of zirconium into the ceria lattice does not have a direct beneficial effect on the soot oxidation activity, although it increases the catalyst performances for CO oxidation. © 2016 American Institute of Chemical Engineers AIChE J, 63: 216-225, 2017 [ABSTRACT FROM AUTHOR]

The embodiment of the NOx selective catalytic reduction (SCR) functionality in a diesel particulate filter (DPF), so-called SCR-on-Filter (SCRoF), is investigated through numerical modeling with SCR kinetics corresponding to Cu-Chabazite and Fe-ZSM5 catalysts. The results of the simulations of the SCR activity, performed in the absence and presence of soot, indicate that the presence of soot negligibly affects the NOx conversion efficiency, given the slow dynamics of passive regeneration. Conversely, the reduction in cake thickness by soot passive oxidation is significantly different in the absence of SCR activity (uncatalyzed DPF) compared to that in its presence (SCRoF). In fact, in the SCRoF only 60-80% of the original soot consumption obtained in the absence of SCR reaction over 1 h can be achieved. Individual Cu-Chabazite and Fe-ZSM5 catalysts, as well as in-series layers of the two catalysts, are investigated to devise the widest temperature window for SCRoF. © 2016 American Institute of Chemical Engineers AIChE J, 63: 238-248, 2017 [ABSTRACT FROM AUTHOR]

The freezing of the food is one of the most important technological developments for the storage of food in terms of quality and safety. The aim of this work was to study the role of an ice structuring protein (ISP) on freezing-thawing cycles of different solutions and commercial Italian pasta sauces. Ice structuring proteins were related to the modification of the structure of ice. The results showed that the freezing time of an aqueous solution containing the protein was reduced to about 20% with respect to a pure water solution. The same effect was demonstrated in sugar-containing solutions and in lipid-containing sauces. The study proved a specific role of ISP during thawing, inducing a time decrease similar to that of freezing and even more important in the case of tomato-based sauces. This work demonstrated the role of ISP in the freezing-thawing process, showing a significant reduction of processing in the freezing and thawing phase by adding the protein to pure water and different sugar-, salt- and lipid-containing solutions and commercial sauces, with considerable benefits for the food industry in terms of costs and food quality. [ABSTRACT FROM AUTHOR]

In the present work, ceria, ceria-zirconia (Ce = 80 at.%, Zr = 20 at.%), ceria praseodymia (Ce = 80 at.%, Pr = 20 at.%) and ceria-zirconia-praseodymia catalysts (Ce = 80 at.%, Zr = 10 at.% and Pr = 10 at.%) have been prepared by the multi-inlet vortex reactor (MIVR). For each set of samples, two inlet flow rates have been used during the synthesis (namely, 2 ml min and 20 ml min) in order to obtain different particle sizes. Catalytic activity of the prepared materials has been investigated for CO and soot oxidation reactions. As a result, when the catalysts exhibit similar crystallite sizes (in the 7.7-8.8 nm range), it is possible to observe a direct correlation between the O/F vibrational band intensity ratios and the catalytic performance for the CO oxidation. This means that structural (superficial) defects play a key role for this process. The incorporation of Zr and Pr species into the ceria lattice increases the population of structural defects, as measured by Raman spectroscopy, according to the order: CeO < CeZr < CeZrPr < CePr. On the other hand, the presence of zirconium and praseodymium into the ceria lattice does not have a direct beneficial effect on the soot oxidation activity for these catalysts, in contrast with nanostructured ones (e.g., Ce-Zr-O nanopolyhedra, Ce-Pr-O nanocubes) described elsewhere (Andana et al. Appl. Catal. B 197: 125-137, 2016; Piumetti et al., Appl Catal B 180: 271-282, 2016). [ABSTRACT FROM AUTHOR]

A series of ceria nanocatalysts have been prepared to study the structure dependency of the CO oxidation reaction. The ceria samples with well-defined nanostructures (nanocubes/Ce-NC and nanorods/Ce-NR) have been prepared using the hydrothermal method. Mesoporous ceria (Ce-MES) and ceria synthesized with solution combustion technique (Ce-SCS) have also been prepared for comparison. The lowest CO oxidation temperature has been reached by using ceria nanocubes (Ce-NC). This high activity draws immense contributions from the highly reactive (100) and (110) surfaces of the truncated nanocubes. The Ce-MES and Ce-SCS samples, despite their high surface areas, are unable to outdo the activity of Ce-NC and Ce-NR due to the abundant presence of (111) crystalline planes. This finding confirms the structure sensitivity of CO oxidation reaction catalyzed with ceria. [ABSTRACT FROM AUTHOR]

This paper presents the optimal design of a rotating eddy-current probe using the inverse problem method. The probe is dedicated to identify the electrical tensor conductivity of carbon fiber composite materials. A 3-D anisotropic shell elements model associated with annealing optimization algorithm is used to minimize the goal function. [ABSTRACT FROM PUBLISHER]

Two numerical models for studying the dynamics of formation and rise of single bubbles in high-viscosity ionic liquids were implemented using the level-set method. The models describe two stages of bubble dynamics: bubble formation at the inlet nozzle and bubble displacement across the column. The models were experimentally validated through a laboratory-scale bubble column using water-glycerol mixtures and two imidazolium-type ionic liquids. The models were consistent with the experimental tests for Reynolds numbers < 5. Outside this range, the models tend to underestimate the bubble terminal velocity, which can be explained by the effect of the high velocity and pressure gradients close to the gas-liquid interface. The models also predicted the velocity and pressure fields near the bubble surface before and after detachment. [ABSTRACT FROM AUTHOR]

In this article the concept, the materials and the exploitation potential of a photosynthetic microbial electrochemical cell for the production of hydrogen driven by solar power are investigated. In a photosynthetic microbial electrochemical cell, which is based on photosynthetic microorganisms confined to an anode and heterotrophic bacteria confined to a cathode, water is split by bacteria hosted in the anode bioactive film. The generated electrons are conveyed through external "bio-appendages" developed by the bacteria to transparent nano-pillars made of indium tin oxide (ITO), Fluorine-doped tin oxide (FTO) or other conducting materials, and then transferred to the cathode. On the other hand, the generated protons diffuse to the cathode via a polymer electrolyte membrane, where they are reduced by the electrons by heterotrophic bacteria growing attached to a similar pillared structure as that envisaged for the anode and supplemented with a specific low cost substrate (e.g., organic waste, anaerobic digestion outlet). The generated oxygen is released to the atmosphere or stored, while the produced pure hydrogen leaves the electrode through the porous layers. In addition, the integration of the photosynthetic microbial electrochemical cell system with dark fermentation as acidogenic step of anaerobic digester, which is able to produce additional H2, and the use of microbial fuel cell, feed with the residues of dark fermentation (mainly volatile fatty acids), to produce the necessary extra-bias for the photosynthetic microbial electrochemical cell is here analyzed to reveal the potential benefits to this novel integrated technology. [ABSTRACT FROM AUTHOR]

As morphology plays a relevant role in solid/solid catalysis, where the number of contact points is a critical feature in this kind of reaction, three different ceria morphologies have been investigated in this work as soot oxidation catalysts: ceria nanofibers, which can become organized as a catalytic network inside diesel particulate filter channels and thus trap soot particles at several contact points but have a very low specific surface area (4 m/g); solution combustion synthesis ceria, which has an uncontrolled morphology but a specific surface area of 31 m/g; and three-dimensional self-assembled (SA) ceria stars, which have both high specific surface area (105 m/g) and a high availability of contact points. A high microporous volume of 0.03 cm/g and a finer crystallite size compared to the other morphologies suggested that self-assembled stars could improve their redox cycling capability and their soot oxidation properties. In this comparison, self-assembled stars have shown the best tendency towards soot oxidation, and the temperature of non-catalytic soot oxidation has dropped from 614°C to 403°C in tight and to 552°C in loose contact conditions, respectively. As far as the loose contact results are concerned, this condition being the most realistic and hence the most significant, self-assembled stars have exhibited the lowest T onset temperature of this trio (even after ageing), thus proving their higher intrinsic activity. Furthermore, the three-dimensional shape of self-assembled stars may involve more of the soot cake layer than the solution combustion synthesis or nanofibers of ceria and thus enhance the total number of contact points. The results obtained through this work have encouraged our efforts to understand soot oxidation and to transpose these results to real diesel particulate filters. [ABSTRACT FROM AUTHOR]

Engineered nanomaterials (ENMs) are growing in interest and use due to the enhancements envisaged in many applications. ENM hazard identification and exposure scenarios are growing in interest too. Inhalation, ingestion and assimilation through skin during ENM production or use have to be considered as possible events, and potential ENM toxicity has to be investigated before new ENM-based products are placed on the market. To design new ENM-based additive in lubricants for automotive application, the European FP7 Project AddNano is investigating the use of fullerene-like inorganic nanomaterials, including transition metal disulphides. In this work, the potential toxicities of well-characterized pristine MoS and WS ENMs were evaluated by in vitro cellular and a cell-free chemical tests. Cytotoxicity and oxidative stress on human pulmonary epithelial cells (A549), ENM surface reactivity (free radical production and lipid peroxidation), and ENM durability in simulated biological fluids were evaluated. In all tests, WS did not elicit a response significantly different from the negative control. MoS showed a moderate cellular toxicity at the highest dose and was inert in all other circumstances. Both WS and MoS were soluble in simulated biological fluids, suggesting a short durability in vivo. The low overall biological and chemical reactivity of WS and MoS suggests that tested nanomaterials are unlikely to be an hazard, as far as human respiratory system is concerned. Data could be usefully implemented in the context of environmental risk assessment and life cycle assessment. [ABSTRACT FROM AUTHOR]

The search for sustainable synthesis pathways for biodiesel generation is still ongoing, although extensive research and development work on this topic has already led to a broad variety of process alternatives, utilizing different feedstocks, alcohols, catalysts and process parameters. Thus, the choice for the most sustainable option is not an easy task, depending on related costs and environmental impacts deriving from up-stream and down-stream processes, but also on safety constraints. The aim of our work presented herein is to demonstrate a decision support procedure for the best suited process design of biodiesel production in front of a pilot plant construction. The development of a novel biodiesel production alternative was accompanied by Life Cycle Management and Risk Analysis in an iterative procedure nearly from the beginning in order to point out favorable process parameter combinations in parallel to experimental optimization. The transesterification of waste oil via supercritical processing in intensifying continuous flow reactors, using the feedstock methanol, was found to be the most favourable option. [ABSTRACT FROM AUTHOR]

Several powder samples obtained from a spent catalytic converter, which contained approximately 1.1% w/w of platinum (Pt), were subjected to a leaching process to assess the relationships between the amount of recovered Pt, the time, and the temperature of the leaching process. The leached powder samples were characterized by X-ray fluorescence (XRF), which showed that the amount of recovered Pt increased linearly with increasing temperature. Our best recovery results (nearly 85% recovery) were reached at a temperature of 100°C, that was applied for 1 h. In the second step of the process, the leached solution was exposed to 100°C for 1 h and then run through ion exchange column with two basic resins: Amberlite-IRA 400 and 900. The aim of this second stage was to eliminate the impurities that originated from the first stage. The purity of the recovered Pt was higher when the process was carried out with the macroreticular matrix resin. Two 2-wt% Pt/Al2O3 catalyst powder samples were synthesized via incipient wetness impregnation, either using recovered platinum or an aqueous hydrogen hexachloroplatinate solution. The activity of these catalysts toward carbon and NO oxidation was assessed using a temperature-programmed combustion (TPC) plant. Results showed that the Tp values (peak combustion temperatures) of carbon oxidation were 555 and 560°C for the commercial Pt and the recovered Pt catalysts, respectively. When the catalysis of NO to NO2 is considered, both catalysts showed similar performances. They both reached their highest conversion (~61%) at 310°C without the production of nitrous oxide. [ABSTRACT FROM AUTHOR]

The 3-D shell elements model is used to determine the sensor impedance variation due to anisotropic metal fiber composite materials (AMFCM). The homogenization of these materials is realized by the inverse problem method. The impedance variation gives the information about the lift off and/or the integrity of the AMFCM. [ABSTRACT FROM AUTHOR]

A methodology based on shell elements, to study the electromagnetic and thermal behavior of multilayered anisotropic conductive composite materials, is presented. The anisotropic behavior and orientation of each layer of the composite material has been taken into account. The model is validated with experimental results. It is then applied to study the induction heating of composite materials, and also to detect the delamination in these materials. [ABSTRACT FROM AUTHOR]

Mitochondrial dysfunction is widely reported in various diseases and contributes to their pathogenesis. We assessed the effect of cocoa flavanols supplementation on mitochondrial function and whole metabolism, and we explored whether the mitochondrial deacetylase sirtuin-3 (Sirt3) is involved or not. We explored the effects of 15 days of CF supplementation in wild type and Sirt3-/- mice. Whole-body metabolism was assessed by indirect calorimetry, and an oral glucose tolerance test was performed to assess glucose metabolism. Mitochondrial respiratory function was assessed in permeabilised fibres and the pyridine nucleotides content (NAD+ and NADH) were quantified. In the wild type, CF supplementation significantly modified whole-body metabolism by promoting carbohydrate use and improved glucose tolerance. CF supplementation induced a significant increase of mitochondrial mass, while significant qualitative adaptation occurred to maintain H2O2 production and cellular oxidative stress. CF supplementation induced a significant increase in NAD+ and NADH content. All the effects mentioned above were blunted in Sirt3-/- mice. Collectively, CF supplementation boosted the NAD metabolism that stimulates sirtuins metabolism and improved mitochondrial function, which likely contributed to the observed whole-body metabolism adaptation, with a greater ability to use carbohydrates, at least partially through Sirt3. [ABSTRACT FROM AUTHOR]