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Extensive researches have been dedicated to study creep in wooden structures where good insight was gained on the phenomenological behaviour. However, long-term creep laws and practical methods to investigate the creep’s influence on safety and serviceability of wood structures during their life-cycle are still very few or don’t exist. This paper investigates the creep of wooden structures using a combined numerical and experimental study. Uni-axial tests (i.e. compression/tensile tests in different directions) were used to calibrate the constitutive law of spruce species and to identify the elastic parameters of the constitutive law. For creep parameters identification, three point bending tests were performed for compressed and uncompressed spruce wood. Subsequently, the results of the three point bending tests were used in conjunction with the numerical model in an inverse problem to obtain the viscous parameters. This technique was adopted for both compressed and uncompressed wood samples. Furthermore, a parametric study was conducted on laminated beams of uncompressed spruce boards assembled by compressed spruce dowels. The behaviour of the whole hybrid structure was studied and several interesting findings were highlighted.

In contrast to neighbouring Maghrebian countries and despite recent progress, knowledge of the Ephemeroptera of Algeria remains fragmentary. As part of an ongoing survey of the Ephemeroptera of Algeria, we investigated the mayfly fauna of Wadi Cherf, a major tributary of the Seybouse River, northeastern Algeria, and present an updated checklist and distribution of Ephemeroptera of this major Maghrebian river. Eighteen species were identified with new records for northeastern Algeria, filling distributional gaps. In addition, two species, Habrophlebia sp. and Procloeon sp., are new to science. A multivariate analysis indicated that mayfly assemblages of the Seybouse River were driven by the physical characteristics of habitats. Species richness was positively correlated with permanent flow and coarse substrate and negatively associated with altitude and salinity. Results also showed that Caenis luctuosa and Baetidae, in particular Baetis gr. pavidus and Cloeon gr. dipterum, dominated the mayfly community.

North African streams and rivers face multiple anthropogenic stressors, and their aquatic fauna is rapidly dwindling before comprehensive knowledge of their distribution and ecology has been attained. We investigated the distribution and life cycle of the Maghrebian endemic Ecdyonurus rothschildi Navas, 1929 in northeastern Algeria. The species was recorded both from permanent and intermittent freshwater habitats with stony substrate. It exhibited pronounced sexual dimorphism, with F-0 females being significantly larger than F-0 males. Three generations were completed during an annual multivoltine cycle. The first generation extended from October to February/March, the second spanned the months of March to June, and the third stretched from June to the end of September/October. We argue that monitoring of E. rothschildi could prove useful for assessing the rapid changes affecting North African hydrosystems, which are in need of adequate management.

In this study, the photodegradation of organophosphorus (OPs) pesticides in the honey medium was evaluated under sunlight irradiation. Some of the 22 samples collected at different sites contained OPs pesticides (Methyl parathion, Coumaphos and Fenitrothion) with an average of 8 ng/g. Moreover, three samples were found with pesticide residue levels exceeding the maximum residue limits (MRL ≥ 50 ng/g) imposed by the standard water (WHO). Gas chromatography (GC) combined with a tritium electron capture detector system was used for the analysis of OPs pesticides in honey. Total degradation of the Methyl parathion was obtained in less than 60 min of irradiation. Moreover, the elimination of the other OPs found in the samples was also effective with a rate of 85% for Coumaphos and Fenitrothion after 50 min of sunlight irradiation. The kinetics of the photodegradation reaction of all OPs pesticides studied followed a pseudo-first order model.

Coastal and mountainous honey samples were collected from different regions in Jijel (Algeria) to evaluate their moisture content, electrical conductivity, ash content, pH, acidity, protein content, color parameters, antioxidants content, radical scavenging activity, reducing power, and antibacterial activity, to reveal the differences between coastal and mountain honeys and to determine the correlation between altitude and different parameters. The results indicate that Jijelian honeys were dark with acceptable physicochemical properties and a good bioactive potential. Escherichia coli was sensitive to Jijelian honeys while Staphylococcus aureus and Pseudomonas aeruginosa were more resistant. Coastal honeys had statistically significantly higher pH, electrical conductivity, ash content, color intensity, hydroxymethylfurfural (HMF) content, and reducing power than the mountainous samples (p

Background: Chronic obstructive pulmonary disease (COPD) is a chronic disease that affects more and more people worldwide. We know today that it is not only a respiratory disease but that there are also extrapulmonary alterations. So we need to find a way to manage these patients as a whole.Objective: The aim of this literature review is to determine whether respiratory rehabilitation has an effect on exercise capacity and tolerance, quality of life and dyspnea.Method: Three scientific databases were searched (Pubmed, Cochrane Library and LILACS) for randomized controlled trial studies.Results: Four studies were selected for analysis. The results were presented in narrative form and with the help of tables for better understanding. We found an improvement of the criteria of judgment in all the studies with however significant values in only two studies.Discussion: Respiratory rehabilitation seems to show positive effects on the improvement of capacity and tolerance to effort, quality of life and a reduction in dyspnea. However, there are still shadowy areas such as the intensity of exercise training, a reference protocol with a predefined duration adapted to the greatest number.; Contexte : La bronchopneumopathie chronique obstructive est une pathologie chronique qui touche de plus en plus de gens dans le monde. Nous savons aujourd’hui qu’elle n’est plus seulement une maladie respiratoire mais que l’on retrouve également des altérations extra-pulmonaires. Il faut donc trouver un moyen de prendre en charge ces patients dans leur globalité.Objectif : Le but de cette revue de littérature est de déterminer si la réhabilitation respiratoire a un effet sur la capacité et la tolérance à l’exercice, la qualité de vie et la dyspnée.Méthode : Trois bases de données scientifiques ont été investiguées (Pubmed, Cochrane Library et LILACS) pour l’obtention des études de type essai contrôlé randomisé.Résultats : Quatre études ont été sélectionnées pour être analysées. Les résultats ont été présentés sous forme narrative et à l’aide de tableau pour une meilleure compréhension. Nous retrouvons une amélioration des critères de jugement dans toutes les études avec cependant des valeurs significatives dans seulement deux études.Discussion : La réhabilitation respiratoire semble montrer des effets positifs sur l’amélioration de la capacité et la tolérance à l’effort, la qualité de vie et une diminution la dyspnée. Il reste tout de même des zones d’ombres telles que l’intensité d’entrainement à l’effort, un protocole de référence avec une durée prédéfinie adapté au plus grand nombre.

We investigated the odonates of Wadi Cherf, a tributary of Wadi Seybouse, and explored the main environmental factors that may be important drivers of the abundance and diversity of Odonata assembl...

The stoneflies and caddisflies of North Africa are still poorly known as vast areas of Algeria have yet to be investigated. A survey of the macroinvertebrates of the Seybouse River, northeast Algeria, was carried out from July 2014 to December 2016. Three species of stoneflies (Capnopsis schilleri, Capnioneura petitpierreae, and Tyrrhenoleuctra tangerina) and five taxa of caddisflies (Mesophylax aspersus, Hydropsyche maroccana, H. resmineda, H. artax/lobata, and H. gr. pellucidula) were identified. All taxa are new records to the Seybouse River and seven of them are new to northeastern Algeria. A multivariate analysis indicated that the Hydropsychidae exhibited a clear longitudinal gradient along the Seybouse River while Mesophylax aspersus seemed adapted to species-poor, intermittent streams. Further investigations of the stoneflies and caddisflies may inform conservation efforts and will prove useful to monitor the Seybouse River and similarly threatened North African rivers and streams.

We investigated the technical feasibility of photochemical hydrogen release based on CuFe2O4 powder dispersion in an aqueous electrolyte containing a reducing agent (\({\text{S}}_{2} {{\text{O}}_{3}}^{ - 2}\)). The oxide combines an average resistance to corrosion and an optimum inter-referred band Eg of 1.67 eV. The intercalation of a small amount of oxygen should be accompanied by partial oxidation of Cu+ to Cu2+ involving a p-type semi-conductivity. The oxidation S2− inhibits the photo-corrosion, and the evolution of H2 increases in parallel with the formation of polysulfides. Most of H2 is produced when p-CuFe2O4 is connected to n-ZnO formed in situ. The release of H2 is mainly on CuFe2O4, whereas, the oxidation of S2− takes place on the surface of ZnO and the hetero-system CuFe2O4/ZnO is optimized with respect to certain physical parameters. The photoelectrochemical production of H2 is a multi-step process whose decisive step is the arrival of electrons at the interface due to their low mobility. Remarkable performance with a rate of 6.74 (μmol g−1 min−1) cm3 h−1 hydrogen evolution in 0.1 M \({\text{S}}_{2} {{\text{O}}_{3}}^{ - 2}\) (pH 13) is recorded.

Engineered Wood Products (EWPs) are increasingly being used as construction and building materials. However, the predominant use of petroleum-based adhesives in EWPs contributes to the release of toxic gases (e.g. Volatile Organic Compounds (VOCs) and formaldehyde) which are harmful to the environment. Also, the use of adhesives in EWPs affects their end-of-life disposal, reusability and recyclability. This paper focusses on dowel laminated timber members and densified wood materials, which are adhesive free and sustainable alternatives to commonly used EWPs (e.g. glulam and CLT). The improved mechanical properties and tight fitting due to spring-back of densified wood support their use as sustainable alternatives to hardwood fasteners to overcome their disadvantages such as loss of stiffness over time and dimensional instability. This approach would also contribute to the uptake of dowel laminated timber members and densified wood materials for more diverse and advanced structural applications and subsequently yield both environmental and economic benefits. The authors wish to record their appreciation to Interreg North-West Europe (NWE) funded by the European Regional Development Fund (ERDF) for supporting the project (Towards Adhesive Free Timber Buildings (AFTB) - 348). peer-reviewed

An advanced numerical model based on the eXtended Finite Element Method (XFEM) is developed and used to investigate the effect of heat transfer and fluid flow on crack propagation in multi-layered SOFC with anisotropic porous layers. Effect of the anisotropy on the onset and the propagation path of cracks are investigated. Heat transport in the porous media is described by heat convection in the fluid phase, and heat conduction in both the fluid and solid phases. A time splitting technique is used to allow different numerical treatment for the heat transfer processes within the porous layer. A combination of Discontinuous Galerkin (DG) and Multi-Point Flux Approximation (MPFA) methods are used to solve the advection–diffusion heat transfer in the flow channel and the fluid phase in the porous material. XFEM is used to solve the heat diffusion within the porous layers and the thermomechanical problem. The fluid flow, governed by Navier–Stokes and Darcy's law, is discretised with the nonconforming Crouzeix–Raviart (CR) finite element method. The multi-physics model is implemented and validated by comparing the computed Stress Intensity Factors (SIF) to ones from the literature. The methodology seems to be robust, accurate and the computational cost is reduced thanks to the XFEM.

A dynamic mathematical model capable of predicting the energy conversion and crack propagation in Solid Oxide Fuel Cell (SOFC) unit is developed. Finite Element Method (FEM) and eXtended Finite Element Method (XFEM) are used to solve the multiphysics phenomenon taking place in the SOFC during service. A pre-existing crack is assumed lying within one of the cell's porous electrodes and far from the cell's electrochemically active sites (electrodes/electrolyte interfaces), and thus it is assumed to not affect the electrochemical reactions. The pre-existing crack propagates instantaneously once the crack-tip equivalent stress intensity factor (SIF) overcomes the porous electrode material toughness. Due to their small opening, cracks are assumed to affect only the heat conduction within the solid phase of the porous electrodes. The coupled fluid flow, fluid's energy transfer in the porous electrodes, and mass transport are solved using advanced FEM based schemes, where transition between SOFC interfaces (mainly porous electrodes/flow channels) does not require any special treatment. The heat transfer in the solid phase of the porous electrodes and the thermo-mechanical problem are solved using the XFEM. The predicted energy conversion is validated using experiments from the literature as well as our previously published experiments [J. Power Sources 272 (2014) 233–238]. The developed FEM/XFEM numerical tool is used to investigate the effect of temperature gradients on the propagation path of a pre-existing crack within an anode-supported SOFC. The crack propagation path is found to depend on the position of the pre-existing crack relative the SOFC interfaces as well as its initial orientation.