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In this study, we will model a light-weight building made of phase change materials (PCMs) to analyze the impact of the building volume, window orientation, and air infiltration on the PCM performance. This is done by calculating the energy savings attained by the use of PCM across all of Morocco. We'll use the commercial Rubitherm panels with RT28HC as a phase change material in this work. Typically, the EnergyPlus simulation engine is chosen to perform the modeling. The impact of building volumes is also evaluated on the PCM activation for light-weight square buildings with different side lengths of 10 m, 9 m, 8 m, and 7 m. Also, we looked at how well the PCM performed in terms of energy savings and thermal regulation at different window orientation placements (south, north, west, and east) and various air infiltration rates (0.5, 1, 1.5, and 3 ACH). This paper's primary objective is to determine the energy savings for the PCM-enhanced building in Morocco, as well as the effect of building volume, window orientation, and infiltration on the PCM capabilities for stabilizing the indoor room temperature. The results show good indoor temperature stabilization during the summer, for the light-weight square building with a south-facing window and no air infiltration. This configuration was able to achieve a total fluctuation reduction of 1303.3 °C for the 10 m building in a semi-arid environment. Besides, a high energy savings percentage of 69.56% was achieved for the PCM-enhanced building with the south-oriented window and air infiltration of 0.5 air change per hour. [ABSTRACT FROM AUTHOR]

Vaccination is a vital strategy to prevent and control the spread of infectious diseases. In this paper, we propose a vaccination strategy that starts with community detection in a dynamic epidemic network, then uses centrality measures to identify spreaders in these communities, who are then targeted for vaccination. By vaccinating the most influential individuals in each community, we aim to achieve a highly vaccinated network that can effectively contain the spread of the disease. To test the effectiveness of the methods, we evaluate them using different evaluation metrics. Our strategy is also highly scalable and adaptable to different epidemic scenarios, making it a promising approach for future epidemic control. [ABSTRACT FROM AUTHOR]

Phosphogypsum (PG) is a byproduct of phosphoric acid production and consists mainly of calcium sulfate (CaSO4). PG management is a critical concern in the phosphoric acid industry. As a solution, PG is decomposed to extract sulfur dioxide (SO2), which is recycled to produce sulfuric acid (H2SO4). Carbon monoxide (CO) decreases the temperature of PG decomposition, producing calcium monoxide (CaO) and calcium sulfide (CaS). This work aims to develop a kinetic model of PG decomposition under reductive conditions by considering the effect of CO partial pressure on the reaction scheme and kinetics. The tests performed with a thermogravimetric analyzer (TGA) at several CO partial pressures and a thermodynamic study indicate that PG decomposition produces CaS and CaO as parallel reactions, while the selectivity towards each of the products depends on the temperature and CO partial pressure. As part of the kinetic study, the kinetics triplet of CaS and CaO production were individually estimated. The activation energy for each reaction, CaS and CaO production, was defined as 259.0 and 140.3 kJ/mol, respectively. The overall kinetic model of PG decomposition with CO reveals that both diffusion and interface reaction (reaction on the surface and adsorption) are equally controlling steps. The PG reduction with CO is achieved by CO adsorption on the CaSO4 surface. [ABSTRACT FROM AUTHOR]

Lead-free Sr0.6Ca0.4TiO3 ceramic was prepared by solid-state reaction route. X-ray diffraction technique showed the phase purity and identified the orthorhombic perovskite structure. Scanning Electronic Microscopy observation evidenced homogeneous morphology and dense microstructure. Electrical conduction and dielectric relaxation mechanisms at high temperature have been studied by complex impedance measurement techniques over a wide range of frequencies and temperatures, from 100 Hz to 1 MHz and from 573 K to 783 K. Fitting of impedance measurements allowed us to study grains and grain boundaries electrical characteristics and their contribution to the conduction and dielectric relaxation processes in the ceramic. Electrical conduction in grains is due to oxygen vacancy jumps for temperatures below 733 K and to polarons above 763 K. Electrical DC conductivity in grains and grain boundaries is mainly due to oxygen vacancies. Impedance measurements and relaxation time distribution function calculations show non-Debye-type relaxation effects for both grains and grain boundaries. [ABSTRACT FROM AUTHOR]

This study investigates the efficacy of a solar-powered single-stage distillation system for treating domestic wastewater, supplemented with complex conductivity analysis. Domestic wastewater samples were collected from a municipal manhole in El Jadida, Morocco, over a 24-h period. The single-stage distillation system, designed for domestic wastewater treatment, utilizes heat to vaporize the wastewater, followed by condensation to produce pure liquid water. The system demonstrated increased distilled water production with rising temperatures, with domestic wastewater outperforming seawater as a feed water source. Physical and chemical testing of the treated water revealed significant improvements in water quality, meeting, or exceeding Moroccan irrigation water standards. Reductions in parameters such as biological oxygen demand (BOD), chemical oxygen demand (COD), suspended matter, and heavy metals underscored the effectiveness of the distillation process. Complex conductivity analysis provided insights into the electrical properties of untreated wastewater and distilled water. Deconvolution of complex conductivity data using an equivalent electrical circuit model elucidated the electrochemical processes during treatment, highlighting the efficiency of the distillation process. The integration of solar energy addresses water scarcity while promoting environmental sustainability. Complex conductivity analysis enhances process understanding, offering avenues for monitoring and control in wastewater treatment. [ABSTRACT FROM AUTHOR]

Intravascular leiomyomatosis (IVL) is a very rare extension of uterine leiomyoma through the pelvic vessels. It is a benign pathology with malignant potential with a possibility of intra-cardiac extension and metastases (cerebral, pulmonary, lymph node); early diagnosis is very difficult. Prognosis depends on involvement of the inferior vena cava and extension to the right cavities. We report a case of complications of IVL, precisely the extension in the right atrium, in a 49-year-old woman. The objective of our work is to highlight the importance of imaging in the diagnosis of the vascular extension of leimyomatosis. [ABSTRACT FROM AUTHOR]

This article presents an analysis and enhancement of the charging behavior of a double‐pipe LHTES unit with longitudinal fins for concentrated solar power applications using a finite element numerical analysis approach. The finite element approach is applied to this numerical analysis by using "COMSOL Multiphysics" software. The investigated LHTES system has an operating temperature range of 180°C‐300°C and uses "DelcoTerm Solar E 15" as the heat transfer fluid (HTF) with a eutectic inorganic mixture of sodium nitrite and sodium nitrate as the phase change material (PCM). While also taking into account the impact of the tube material and the number of fins, the primary goal of this study is to evaluate performance improvement by changing the thickness and number of fins in a linked manner without changing the storage unit capacity. The results show a maximal impact on thermal performance which decreased the melting time by 46% and the charging time by 49.6% for the configuration with a fin thickness of 1 mm, 27 longitudinal fins, an inner tube made of aluminum, and a mass flow rate of 60 kg/h. [ABSTRACT FROM AUTHOR]

The study investigates the effectiveness of Ferric Chloride as a coagulant for removing pollutants from domestic wastewater in El Jadida, Morocco. It analyzes various parameters, including Total Suspended Solids (TSS), Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), pH levels, and heavy metals. The study combines conventional methods with impedance spectroscopy to monitor the process, and an equivalent circuit model is developed to correlate theoretical factors with empirical data. The study reveals that a concentration of 1000 mg/L of Ferric Chloride is optimal for effective treatment, significantly reducing TSS, BOD, and COD levels. However, higher concentrations show diminishing returns. The study also highlights the presence of heavy metals exceeding Moroccan standards in the wastewater, emphasizing the need for proper treatment. The impedance analysis elucidates the relaxation processes associated with the coagulation reaction and the migration/agglomeration of flocs. The analysis suggests that below 1000 mg/L, more Ferric Chloride is required for effective coagulation, while above 1000 mg/L, overcoagulation may occur. Complex conductivity analysis confirms the presence of two distinct relaxation processes in the samples. The equivalent circuit model accurately describes the electrical spectra. [ABSTRACT FROM AUTHOR]

Several nonlinear treatments of piezoelectric voltages have been studied and developed. These techniques greatly improve the switching capabilities of piezoelectric materials. There are active and passive vibration control techniques: Passive technology involves connecting piezoelectric elements to a passive grid; and active technology requires a bulky system that contains at least a sensor, a controller, and a feedback actuator. In addition, control units and actuators require external power supplies and amplifiers. In addition, control units and actuators require external power supplies and amplifiers. SSD (Synchronous Switch Damping) technology allows optimal management of energy transfer in multiphysical couplings, especially electromechanical couplings created by piezoelectric elements. Based on nonlinear manipulation of the voltage of active elements embedded in the host structure, they greatly increase the extracted mechanical energy, which is then converted into electrical energy. Two main areas can benefit from this optimization: vibration control (SSD) technology, because more energy is extracted from the structure to minimize its energy vibration, and energy harvesting (SSH) technology, because the harvested electrical energy becomes sufficient to supply low consumption electronic circuits. This work focuses on vibration control and energy harvesting using embedded piezoelectric elements. First, the SSD principle applied to piezoelectric materials is introduced. Then, a summary is presented of the work consisting on estimating the attenuation obtained on the vibrations of an optical arm by non-linear SSD techniques. [ABSTRACT FROM AUTHOR]

The main aim of this study was to develop and monitor an effective and cost-efficient industrial wastewater treatment system that utilizes sand, fly ash, and hearth ash. The latter two are potentially available and inexpensive industrial waste materials that can be used for filtration. The infiltration percolation method was utilized in a vertical cylindrical column to filter the raw wastewater from a detergent manufacturing plant. The main parameters analyzed before and after treatment included suspended solids (SS), chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and pH. The system successfully achieved significant reductions, including 89% in COD, 73% in BOD5, and 54% in suspended solids (SS), along with a 66% to 99% reduction in heavy metals. The COD/BOD5 rejection ratio decreased from above 4.24 before treatment to below 1.73 after treatment. Furthermore, impedance measurements were carried out across the frequency range of 100 to 1 MHz. The analysis of complex conductivity spectra revealed two Cole–Cole relaxation behaviors, and an equivalent circuit was developed to extract the primary parameters and further investigate both relaxation processes. The results of the electrical parameters deduced from the impedance spectra demonstrated a strong correlation with the parameters obtained through conventional methods. [ABSTRACT FROM AUTHOR]

This work aims to propose an implicit algorithm for solving the magnetoelastic wave propagation in a magnetostrictive actuator. This algorithm is built by combining meshless methods with the Newmark implicit time scheme. The mathematical formulation of vibrations of the actuator is performed by modeling the experimental actuator device by a monodimensional magnetostrictive cylindrical rod attached to an elastic spring, subjected to an axial magnetic field. The formulation of the problem is carried out using the rod model. The study is carried out taking into account mechanical and magnetic effects described by a linear model of strain-stress magnetoelastic relations, whose coefficients depend on the square of the magnetic field, elastic, magnetostrictive, and magnetoelastic characteristics of the elastomagnetic material of which the rod is made. The dynamic equation which describes the magnetoelastic wave propagation in the actuator is obtained by applying the Lagrangian formalism based on the least action principle. The wave propagation is governed by a spatio-temporal partial differential equation whose coefficients are a function of on elastic, magnetostrictive, and magnetic characteristics and implicitly depends on time. The resolution of the dynamic equation is made by adopting two numerical approaches developed by combining the mesh-free collocation methods, the Moving Least Squares (MLS), and the Radial Point Interpolation Method (RPIM) with the Newmark implicit scheme temporal integration. By performing the spatial discretization of the displacement, we obtain a system of linear second-order ordinary differential equations (ODEs), then transform it into a system of first-order ordinary differential equations after integrating Newmark's implicit time scheme. A comparison of results computed by the proposed numerical approaches RPIM and MLS with experimental data available in the literature is presented. The stability and the solutions qualities of two meshless methods, RPIM and MLS, are also studied. The influence of magnetical and mechanical parameters as well as the coupling coefficients on the performance of the magnetostrictive actuator is also made. [ABSTRACT FROM AUTHOR]

Our patient had an extremely rare type of pediatric Diffuse Midline Glioma (DMG) with modified H3 K27 that occurred in the cervical spinal cord. Due to its location in the spinal cord, slow clinical presentation with torticollis for 7 months, and the non-specific radiological appearance of this tumour, it was initially considered to be a lowgrade glioma. Based on imaging findings, the neurosurgery team performed a complete surgical resection, but the pathological features were consistent with a high-grade, diffuse midline glioma. Therefore, we are reporting a case of an altered high-grade DMG H3K27 glioma, which is difficult to diagnose due to its slow clinical symptoms which caused a delay in diagnosis, nonspecific imaging, and with difficulty in accessing histopathological markers in low and middle income countries (LMIC). [ABSTRACT FROM AUTHOR]

In this study, we numerically investigated the hydrothermal performance of a parabolic trough solar collector system in which nanofluids are used to transfer thermal energy. The single-phase model has been used to evaluate the respective influences of the spherical shape of nanoparticles with a volume fraction of (φ = 3%), Reynolds number varying between 50,000 ≤ Re ≤ 250,000 and the insertion of a turbulator with and without a twisted configuration on the hydrothermal characteristics created by the turbulent forced convection of a CuO/water nanofluid. The shaped turbulator (+) inserted in the absorber tube had a length turb_L = 2.4 m, a height turb_H = 40 mm and a width turb_t = 2 mm. In the second configuration, the considered turbulator was twisted (N_twist = 5, 10 and 15 twists). The turbulator was positioned at 0.6 m from the inlet of the tube and 1 m from the outlet of the collector. The studied performances included the heat transfer characteristics, pressure drop, friction factor, thermal efficiency, temperature and velocity distribution of the outlet field. The most significant contribution of this study is the proposal of the best parameters to increase the thermal and hydraulic efficiency of parabolic troughs by adding a new turbulator with the considered twists. [ABSTRACT FROM AUTHOR]

In recent decades, researchers have focused more on the use of many types of biomaterials from various organisms and agricultural by-products for wastewater treatment. In this study, we are using Moringaoleifera pods powder (MOPP) and Moringaoleifera kernels powder (MOPK) for the removal of industrial Methylene blue (MB) dye from aqueous solutions. The adsorption process of MB onto MOPP and MOKP follows the pseudo-second-order model. First of all, the adsorbents were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscope (SEM). The second objective was the optimization process of Moringaoleifera wastes seeds (MOPP and MOKP) for the removal of methylene blue dye (MB), using Box-Behnken under the Response Surface methodology. The optimal conditions were X1 = 2.5 g/L of adsorbent, X2 = 40 ppm of concentration of MB and X3 = 10.03 of pH with removal efficiency which reaches 98.12% for MOPP and X1 = 2.5 g/L of adsorbent, X2 = 30 mg/L of concentration of MB and X3 = 7.43 of pH with removal efficiency which reaches 96.94% for MOKP. The model envisaged for the optimal design has been well verified by the experimental data, with R2/R2adj equal to 0.99 and 0.74, respectively for MOPP, then for MOKP 0.90 and 0.73. Finally, the analysis of variance (ANOVA), confirmed that MOPP and MOKP had a high-efficiency adsorbent capacity with the MOPP as the best biosorbent than MOKP and that the chosen model is valid. The two materials could be adopted as efficient and cost-effective adsorbents. [ABSTRACT FROM AUTHOR]

The present paper investigates the optimum results on the performance of a parabolic trough solar collector using (3%) CuO-water nanofluid. The single-phase model based on a three-dimensional CFD method is used to model and numerically study the heat transfer behavior and fluid flow under a turbulent regime. Effects of various parameters, including different inlet Reynolds numbers (50000 ≤ Re ≤ 250000), pipe length (0,25 m ≤ L ≤ 8 m) and pipe inner diameter (di = 60 mm, 66 mm, 72 mm, 78 mm, 82 mm, 86 mm) on the thermal and hydraulic efficiency of a parabolic trough solar collector are studied and discussed. [ABSTRACT FROM AUTHOR]

Corrosion inhibition effect of Rumex Nervosus Vhal Leaves Extract (RNVLE) on C38 steel in a 1 M HCl medium has been investigated by electrochemical techniques. Inhibition efficiency of (96.0%) and (95.5%) were achieved with (2 g L−1) at ambient temperature. The polarization studies showed that RNVLE acts as a mixed-type inhibitor. The Nyquist plots showed that increasing RNVLE concentration increases charge transfer resistance and decreases double layer capacitance. RNVLE obeys the Langmuir adsorption isotherm. By noting and matching the values of the correlation coefficient R2 of various adsorption isotherms, the adsorption of our inhibitor RNVLE obeys the Langmuir isotherm (R2 = 0.999). RNVLE controls the corrosion process through physisorption, according to the calculated free energy (ΔG0ads = –16.1 KJ mol−1). The impact of immersion time was also studied, this study showed that RNVLE could be a good inhibitor for up to 6 h − where the inhibition efficiency at this time was 94.2% − before becoming a lower-quality inhibitor even though it still has a strong inhibitory effect. The extract molecules adsorb on the surface of the metal, according to SEM-EDX analysis, which combines scanning electron microscopy and X-ray energy dispersive spectroscopy. The RNVLE can be regarded as an effective corrosion inhibitor for C38 steel in 1M HCl solution, according to these results. [ABSTRACT FROM AUTHOR]

This work investigated the effect of temperature on corrosion of C38 steel in a hydrochloric medium (1M) in the absence and presence of the ethanolic extract from Eriobotrya Japonica (ERJ) seeds treated by maceration. For a better understanding of the corrosion process, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques had applied by increasing the temperature from 303.15 K to 333.15 K. Moreover, studying adsorption isotherms and determining thermodynamic parameters to understand the mechanism adopted in the adsorption of ERJ molecules on the metal surface. The results reveal that the inhibition efficiency increases with higher inhibitor concentration and decreases slightly with increasing temperature. Thus, the Langmuir model is the best model to fit the data obtained, and the adsorption follows a spontaneous physisorption process. According to the evolution of enthalpy, entropy, and activation energy, the inhibition capacity decreases is associated with a slow endothermic dissolution due to forming an active complex on the surface of C38. [ABSTRACT FROM AUTHOR]

Pantothenate kinase-associated neurodegeneration (or previously known as Hallervorden-Spatz syndrome) is a very rare disorder that typically manifests in a child with neurological signs such as gait difficulties, dysarthria, and hyperreflexia, associated potentially with psychiatric symptoms such as cognitive decline. It demonstrates on MRI the typical 'eye of the tiger' appearance, which is due to gliosis and accumulation of iron in the globi pallidi. Other differentials can mimic this appearance on MRI, it is therefore important to search for the involvement of other basal ganglia nuclei and the cerebral cortex, and also to consider the clinical and biological context. [ABSTRACT FROM AUTHOR]

We study a class of non-autonomous linear boundary control and observation systems that are governed by non-autonomous multiplicative perturbations. This class is motivated by fundamental partial differential equations, such as controlled wave equations and Timoshenko beams. Our main results give sufficient condition for well-posedness, existence and uniqueness of classical and mild solutions. [ABSTRACT FROM AUTHOR]

In the environment, water is present in a wide variety of scenes, and its detection enables a broad range of applications such as outdoor/indoor surveillance, maritime surveillance, scene understanding, content-based video retrieval, and automated driving as for unmanned ground and aerial vehicles. However, the detection of water is a delicate issue since it can appear in quite varied forms. Moreover, it can adopt simultaneously several textural, chromatic and reflectance properties. The diversification of water appearances makes their classification in the same class a quite difficult task using the general dynamic texture recognition methods. In this work, we propose a new more appropriate approach for recognition and segmentation of water in videos. In this approach, we start with a preprocessing phase in which we homogenize the aspect of the different aquatic surfaces by eliminating any differences in coloration, reflection and illumination. In this phase, a pixel-wise comparison is introduced leading to a unidirectional binarization. Two segmentation steps are then deployed: preliminary segmentation and final segmentation. In the first segmentation, candidate regions are first generated and then classified by applying our spatiotemporal descriptor. This descriptor investigates both spatial and temporal behavior of textures on a local scale through a sliding window. Secondly, a superpixel segmentation is applied in order to regularize the classification results. The proposed approach has been tested using both the recent Video Water and the DynTex databases. Furthermore, it has been compared with other similar work, and with other dynamic texture and material recognition methods. The obtained results show the efficiency of the proposed approach over the other methods. Additionally, its low computational cost makes it suitable for real-time applications. [ABSTRACT FROM AUTHOR]

Hybrid composites have been elaborated by incorporation of BaTiO3 (BT) inorganic nanoparticles into polyvinylidene fluoride (PVDF) polymer. BT–PVDF composite thick films with different volume fractions of BT (0%, 7%, 15%, and 30%) were deposited by spin-coating onto Pt/SiO2/Si substrates. The effects of the BT inorganic content in the PVDF polymeric matrix on the structural, dielectric, ferroelectric, and energy storage properties were investigated at room temperature. The crystal structure of the samples was identified by X-ray diffraction analysis, and their morphology was observed by scanning electron microscopy. Introduction of BT nanoparticles into the PVDF polymer led to a remarkable enhancement of the dielectric constant value and ferroelectric polarization. Additionally, the abnormal dielectric behavior observed for the composite with 30 vol.% BT nanoparticle volume fraction can be explained by the existence of a Debye relaxation domain at low frequency. Moreover, the stored energy density Wc was enhanced from 2.4 J/cm3 for pure PVDF polymer to 9 J/cm3 for the 30 vol.% BT nanoparticle volume fraction. Such BT–PVDF composite thick films are thus promising materials for the manufacture of electrostatic capacitors for electrical energy storage. [ABSTRACT FROM AUTHOR]

Summary: The effect of Zr substitution by alkaline earth metals Mg, Be and post‐transition metal Al on the evolution of hydrogen storage properties of ZrNiH3 has been investigated by ab‐initio calculations based on density functional theory. The stability of the quaternary hydrides is studied by the determination of the formation enthalpy and the desorption temperature. The obtained results indicate a reduction of the formation enthalpy as well as the desorption temperature, hence reflecting the enhancement of hydrogen storage properties of ZrNiH3. Interestingly, each dopant (Mg, Be and Al) achieved its optimum substitution effect at a particular concentration, with Al and Be elements are found to exhibit the lowest substituting content ~17% and ~23% respectively and Mg with the highest concentration ~85%, to achieve an ideal formation enthalpy (ΔH = −40 kJ/mol.H2) and desorption temperatures (289 to 393 K), as required for practical use of proton exchange membrane fuel cells (PEMFC) without affecting the hydrogen storage capacity as seen in pure ZrNiH3.Moreover, the electronic structure investigated by partial density of states (PDOS), reveals the metallic nature of Zr1−xAMxNiH3 (AM = Mg, Be and Al) hydrides. Highlights: The ZrNiH3 hydride presents high stability and high decomposition temperature.The stability decreases significantly when doping ZrNiH3 with Mg, Be and Al.The density of states reveals the metallic nature of Zr1−xAMxNiH3 hydrides. [ABSTRACT FROM AUTHOR]

Background. Lichens present a complex symbiotic relationship between a filamentous fungus, photoautotrophic partner (algae or cyanobacteria), and bacterial community. The Objective of the Study. This study aimed at investigating the chemical composition and cytotoxic, antioxidant, and antimicrobial activities of acetone extracts of Moroccan Evernia prunastri (E. prunastri), Ramalina farinacea (R. farinacea), and Pseudevernia furfuracea (P. furfuracea). Materials and Methods. The phytochemical analysis was carried out by HPLC-UV. The cytotoxic effect was assessed on human prostate cancer (22RV1), human colon carcinoma (HT-29), human hepatocellular carcinoma (Hep-G2), and Hamster ovarian cancer (CHO) cells lines by WST1 assay. The antioxidant power was assessed by DPPH and FRAP assays. The antibacterial effect was obtained using the broth microdilution method. Results. The findings of phytochemical analysis showed that the lichens studied possess interesting bioactive molecules such as physodalic acid, evernic acid, and usnic acid, as well as protocetraric acid. According to the American National Cancer Institute guidelines, the WST-1 test showed that all crude extracts did not show significant cytotoxic effects against all concerous cell lines, and IC50 values ranged from 42.30 to 140.24 µg/mL. Regarding the antioxidant activity, P. furfuracea extract showed the highest free-radical-scavenging ability (IC50 = 498.40 µg/mL). The most potent antibacterial extract was recorded for P. furfuracea extract with a minimum inhibitory concentration (MIC) ranging from 0.039 to 0.31 mg/mL. Conclusion. In this research work, we report that the studied lichen extracts exhibit an important biological effect, supporting that lichens represent a hopeful source of original natural products for the research of new bioactive molecules having a pharmaceutical interest. [ABSTRACT FROM AUTHOR]

It is reported in this paper on the thermally assisted flux flow in epitaxial YBa2Cu3O7-δ deposited by Laser ablation method on the SrTiO3 substrate. The resistivity measurements ρ (T, B) of the sample under various values of the magnetic field up to 14T in directions B∥ab-plane and B∥c-axis with a dc weak transport current density were investigated in order to determine the activation energy and then understand the vortex dynamic phenomena and therefore deduce the vortex phase diagram of this material. The apparent activation energy U0 (B) calculated using an Arrhenius relation. The measured results of the resistivity were then adjusted to the modified thermally assisted flux flow model in order to account for the temperature-field dependence of the activation energy U (T, B). The obtained values from the thermally assisted activation energy, exhibit a behavior similar to the one showed with the Arrhenius model, albeit larger than the apparent activation energy with ∼1.5 order on magnitude for both cases of the magnetic field directions. The vortex glass model was also used to obtain the vortex-glass transition temperature from the linear fitting of [d ln ρ/dT ] −1 plots. In the course of this work thanks to the resistivity measurements the upper critical magnetic field Hc2 (T), the irreversibility line Hirr (T) and the crossover field HCrossOver (T) were located. These three parameters allowed us to establish a phase diagram of the studied material where limits of each vortex phase are sketched in order to optimize its applicability as a practical high temperature superconductor used for diverse purposes. [ABSTRACT FROM AUTHOR]

Ceramics arising from Pb(Mg1/3Nb2/3)1‑x TixO3 with composition near the morphotropic phase boundary (MPB) were prepared by the modified solid-state reaction method. The synthesized ceramics were characterized, and then the operating principles of pyroelectric and piezoelectric harvesters are reviewed. In addition, the dielectric behavior is measured to determine the dielectric constant and losses at different temperatures and frequencies. The typical behavior of a ferroelectric relaxer was observed by adding the PbTiO3 phase. The thermal properties are also analyzed by PPE calorimetry, presaging a one-dimensional heat-flow process. As a result, the dielectric and thermal behaviors of the as-prepared ceramics as well as their thermal stability are intimately linked to the PbTiO3 addition to PbMgl/3Nb2/3O3 phase. These materials exhibit good physical performances, which makes them promising candidates for pyroelectric micro-generators (PEG), cooling systems and infrared applications. [ABSTRACT FROM AUTHOR]

We consider evolution equations of the form u ˙ (t) + A (t) u (t) = 0 , t ∈ [ 0 , T ] , u (0) = u 0 , where A (t) , t ∈ [ 0 , T ] , are associated with a non-autonomous sesquilinear form a (t , · , ·) on a Hilbert space H with constant domain V ⊂ H. In this note we continue the study of fundamental operator theoretical properties of the solutions. We give a sufficient condition for norm-continuity of evolution families on each spaces V, H and on the dual space V ′ of V. The abstract results are applied to a class of equations governed by time dependent Robin boundary conditions on exterior domains and by Schrödinger operator with time dependent potentials. [ABSTRACT FROM AUTHOR]

We develop a variational approach in order to study qualitative properties of nonautonomous parabolic equations. Based on the method of product integrals, we discuss invariance properties and ultracontractivity of evolution families in Hilbert space. Our main results give sufficient conditions for the heat kernel of the evolution family to satisfy Gaussian‐type bounds. Along the way, we study examples of nonautonomous equations on graphs, metric graphs, and domains. [ABSTRACT FROM AUTHOR]

With recent advancements in energy conversion mechanisms, piezoelectric ceramics (1–x)PbMg1/3 Nb2/3Ο3-xPbTiΟ3 (1–x)PMN-xPT have demonstrated their abilities for converting mechanical vibrations into electricity. Three (1–x)PMN-xPT compositions were used in the present work with (x = 0.25, 0.31 and 0.33). The purpose of this paper is to investigate their piezoelectric performance as generators for energy harvesting applications. The energy harvester is numerically analyzed in this work. It consists of a piezoelectric bimorph clamped at one end to vibrating machinery, and a proof mass mounted on its other end. The energy harvester is also analyzed and experimental measurements of the harvested power are compared to the simulation results. A good agreement was observed between the experimental and the simulations results. According the application to exploit the vibrations of a hot air extractor, the results show that the harvested energy density of solid ceramics (1–x)PMN-xPT is 0.043 W/m2. [ABSTRACT FROM AUTHOR]

Background. Rosmarinus officinalis (R. officinalis) is a medicinal plant called rosemary, largely used in the Mediterranean diet for many decades ago. Objective. The aim of the present study was to investigate the polyphenolic content, the antioxidant activity, and the antiproliferative effect against human prostate cancer cell lines (LNCaP) of carnosol and carnosic acid as bioactive compounds contained in R. officinalis growing in Morocco. Materials and Methods. Polyphenolic content of R. officinalis ethanolic extract was studied using colorimetric assay. Carnosol and carnosic acid contained in R. officinalis extract were quantified using high-performance liquid chromatography (HPLC). The antiproliferative effect of the studied extracts on LNCaP was evaluated by WST-1 bioassay, and the antioxidant activity was assessed using DPPH assay. Results. The extracts of R. officinalis showed an important polyphenolic content ranging from 74.15 μg·GAE/mg to 146.63 μg·GAE/mg. The percentage of carnosol and carnosic acid in rosemary crops ranges from 11.7 to 17.3% and 1.09% to 3%, respectively. The extracts of R. officinalis exhibited a promoting antioxidant activity with IC50 ranging from 0.236 mg/mL to 0.176 mg/mL. Regarding the antiproliferative effect, the WST-1 assay revealed that all the tested extracts reduced notably the cell viability with IC50 values ranging from 14.15 to 15. 04 μg/mL. Conclusion. In the current work, carnosol and carnosic acid exhibit antioxidant and antiproliferative activities in a concentration-dependent manner. [ABSTRACT FROM AUTHOR]

We successfully fabricated polycrystalline zinc oxide catalyst-free nanorods by a successive ion layer adsorption and reaction process. We measured their optical transmittance, reflectance and thickness in addition to performing X-ray diffraction and probing film microscopic topology. We extracted different optical constants such as absorption coefficient, band gap, complex refractive index and complex dielectric function and inferred the behavior of the optical conductivity and show the supremacy of the obtained ZnO nanostructure over a bulk material. It turns out that it is possible to obtain ZnO nanorods ultra-thin film with optical quality almost similar to those obtained by a contaminant metal catalyst approach requiring extra cost. [ABSTRACT FROM AUTHOR]

Nowadays energy storage seems to be a vital point in any new energy paradigm. It has become an important and strategic issue, to ensure the energetic sufficiency of humanity. Indeed, hydrogen storage in solids has been proved and revealed as clean and efficient energy storage. Moreover, it can be thought as a seriously considered solution to enable renewable energy to be a part of our quotidian life. To achieve storing hydrogen in solid form, the present study aimed to concepts and simulates a solid-state hydrogen storage reactor (tank). An investigation of the parameters influencing the hydrogen storage performance is carried out. Meanwhile, to understand the physical phenomenon taking place during the storage of hydrogen, a 2D numerical modelling for a metal hydrides-based in hydrogen reactor is presented. A strong coupling between energy balance, kinetic law, as well as a mass momentum balance at sorbent bed temperature under a non-uniform pressure was resolved based on finite element method. The temporal evolutions of pressure, the raising temperature in the bed during the hydriding process as well as the impact of the hydrogen supply pressure within the tank are analysed and validated by comparison with the experimental work in literature, a good agreement is obtained. From an industrial point of view, this study can be used to design and manufacture an optimal solid-state hydrogen storage reactor. [ABSTRACT FROM AUTHOR]

Building retrofitting plays a key-role in energy saving and a growing interest is focused on insulating materials that allow a reduction in heat loss from envelopes with low thickness, by a process of reducing heating and cooling demand. In this context, a complete characterization of the physical properties of Moroccan natural gypsum materials was carried out. Basic information on the mineralogical, microstructure, thermal, mechanical, and acoustic characteristics of the rocks sampled from two Moroccan regions is provided. It was found that mineralogy, porosity, and water content are the main factors governing the development of the structure and the strength of the samples. The measured values of the porosity were 8.94%, the water content varied between 2.5–3.0% for the two studied typologies, coming from Agadir and Safi, respectively. Gypsum powder was used for fabricating samples, which were investigated in terms of thermal and acoustic performance. Thermal properties were measured by means of a hot disk apparatus and values of conductivity of 0.18 W/mK and 0.13 W/mK were obtained for Agadir and Safi Gypsum, respectively. The acoustic performance was evaluated in terms of absorption coefficient and sound insulation, measured by means of a Kundt's Tube (ISO 10534-2). The absorption coefficients were slightly higher than the ones of conventional plasters with similar thickness. A good sound insulation performance was confirmed, especially for Safi Gypsum, with a transmission loss-value up to about 50 dB at high frequency. [ABSTRACT FROM AUTHOR]

The generation of Municipal Solid Waste (MSW) is inevitable. With population growth year after year and the increase in the standard of living, the quantities of waste are increasing exponentially and their efficient management has become a priority to municipal authorities worldwide. The Moroccan government has recognized the importance of effective sustainable resource management and the implementation of a national strategy as waste management. In Morocco, the Secretariat of State for Sustainable Development and the Ministry of the Interior have developed a waste management strategy called the National Household Waste Management Program (PNDM), which was implemented with the support of the World Bank, which targets for the next few years the quantitative objectives of waste collection (90% in 2020), the implementation of controlled landfills and the development of waste sorting, recycling and valorization. Waste energy recovery is the most optimal management solution that not only eliminates the large quantities of waste produced each day but also creates the energy needed for a constantly growing population. The objective of this research work is to assess the municipal solid waste potential for electrical and thermal energy generation and biogas production using three modes of energy recovery (combustion, gasification and anaerobic digestion) in Oujda city (Morocco). The maximum electric load generated is 177.39 GWh from waste gasification with electrical efficiencies of 17.3%. Whereas for thermal energy, a maximum value of 277.17 GWh is generated by direct combustion of MSW. For anaerobic digestion, the maximum potential methane generation capacity is 2.44 106 m3/year in 2014. [ABSTRACT FROM AUTHOR]

Evolution families are the non-autonomous counterpart of operator semigroups in the well-posedness theory of non-autonomous evolution equations. This note is devoted to fundamental operator theoretical properties, beginning with norm continuity—which we regard as a fingerprint of analyticity. While no known analogue of analytic semigroups is known in the non-autonomous case, we give a sufficient condition for norm-continuity of evolution families. Furthermore, we develop a theory of compact and trace class evolution families. The abstract results are applied to the Laplace operator with time dependent Robin boundary conditions. [ABSTRACT FROM AUTHOR]

The objective of this research was to assess the microbiological status of leafy greens, sprouts, and melons from U.S. markets. A total of 14,183 samples of leafy greens, 2,652 samples of sprouts, and 3,411 samples of melons were collected throughout the United States from 2009 to 2014. The samples were analyzed for aerobic plate counts, total coliform counts, Escherichia coli counts, and the presence and levels of Salmonella, Shigella, Listeria monocytogenes, and Shiga toxin--producing E. coli (STEC), depending on the year and type of produce. Among the leafy greens, no E. coli O157:H7 or non-O157 STEC were detected from iceberg lettuce samples. The overall prevalences of Salmonella, E. coli O157:H7, non-O157 STEC, and L. monocytogenes in the 14,183 samples of leafy greens were 0.05, 0.01, 0.07, and 0.11%, respectively. Among sprout samples, no Salmonella or E. coli O157:H7 was detected, and the overall prevalences of non-O157 STEC and L. monocytogenes were 0.04 and 0.11%, respectively. Among melon samples, no Salmonella was detected from cucumbers, no L. monocytogenes was detected from cantaloupes, and the overall prevalences of Salmonella and L. monocytogenes were 0.12 and 0.23%, respectively. L. monocytogenes levels were 0.4 to 1,470 most probable number (MPN)/g in leafy greens, 0.36 to 1,100 MPN/g in sprouts, and <0.03 to 150 MPN/g in melons, and most positive samples had low levels of these pathogens. The isolates from these foods were very diverse genetically. Foodborne pathogens, including Salmonella, STEC, and L. monocytogenes, had relatively low prevalences in the produce surveyed. Because these foods are usually consumed raw, measures should be taken to significantly minimize the presence and levels of human pathogens. [ABSTRACT FROM AUTHOR]

The recent developments in measurement technology have led to the installation of efficient monitoring systems on many bridges and other structures all over the world. Nowadays, more and more structures have been built and instrumented with sensors. However, calibration and installation of sensors remain challenging tasks. In this paper, we use a case study, Adige Bridge, in order to present a low-cost method for the calibration and installation of elasto-magnetic sensors on cable-stayed bridges. Elasto-magnetic sensors enable monitoring of cable stress. The sensor installation took place two years after the bridge construction. The calibration was conducted in two phases: one in the laboratory and the other one on site. In the laboratory, a sensor was built around a segment of cable that was identical to those of the cable-stayed bridge. Then, the sample was subjected to a defined tension force. The sensor response was compared with the applied load. Experimental results showed that the relationship between load and magnetic permeability does not depend on the sensor fabrication process except for an offset. The determination of this offset required in situ calibration after installation. In order to perform the in situ calibration without removing the cables from the bridge, vibration tests were carried out for the estimation of the cables’ tensions. At the end of the paper, we show and discuss one year of data from the elasto-magnetic sensors. Calibration results demonstrate the simplicity of the installation of these sensors on existing bridges and new structures. [ABSTRACT FROM AUTHOR]