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In this paper, some new polythiophenes containing benzo[d]thiazole heterocycle were synthesized by the oxidative polymerization in chloroform using iron(III) chloride as a catalytic oxidant. Infrared (IR) spectroscopy and ultraviolet–visible (UV-Vis) spectroscopy analyses confirmed that the polymerization reaction successfully took place and the absorption band at 497 nm is typical for π–π* transition in the conjugated polythiophenes. The polymers are composed of relatively uniform particles using field emission scanning electron microscopy (FESEM) method. Based on thermal gravimetric analysis (TGA), the polymers had average thermal stability in the atmosphere when decomposed completely at 500 oC. The polymers exhibited fluorescence emission at about 516 nm due to the conjugated chain in the polymers.

Optimization of steel moment frames has been widely studied in the literature without considering shear deformation of panel-zones which is well-known to decrease the load-carrying capacity and increase the drift of structures. In this paper, a robust method for optimizing steel moment frames is developed in which the panel-zone design is considered by using doubler plates. The objective function is the total cost of beams, columns, and panel-zone reinforcement. The strength and serviceability constraints are evaluated by using a direct design method to capture the nonlinear inelastic behaviors of the structure. An adaptive differential evolution algorithm is developed for this optimization problem. The new algorithm is featured by a self-adaptive mutation strategy based on the p-best method to enhance the balance between global and local searches. A five-bay five-story steel moment frame subjected to several load combinations is studied to demonstrate the efficiency of the proposed method. The numerical results also show that panel-zone design should be included in the optimization process to yield more reasonable optimum designs. Keywords: direct design; differential evolution; optimization; panel-zone; steel frame.

Timely monitoring the large-scale civil structure is a tedious task demanding expert experience and significant economic resources. Towards a smart monitoring system, this study proposes a hybrid deep learning algorithm aiming for structural damage detection tasks, which not only reduces required resources, including computational complexity, data storage but also has the capability to deal with different damage levels. The technique combines the ability to capture local connectivity of Convolution Neural Network and the well-known performance in accounting for long-term dependencies of Long-Short Term Memory network, into a single end-to-end architecture using directly raw acceleration time-series without requiring any signal preprocessing step. The proposed approach is applied to a series of experimentally measured vibration data from a three-story frame and successful in providing accurate damage identification results. Furthermore, parametric studies are carried out to demonstrate the robustness of this hybrid deep learning method when facing data corrupted by random noises, which is unavoidable in reality. Keywords: structural damage detection; deep learning algorithm; vibration; sensor; signal processing.

This paper presents the doping influence of both molybdate anion and 10-camphorsulfonic acid (CSA) on the characterization and corrosion protection properties of polypyrrole (PPy) film prepared on passivized CT3 mild steel. The effect of CSA and molybdate anion concentrations on the properties and morphology of PPy film was characterized by Raman, FTIR, EDX and SEM methods. The doping of both CSA and molybdate anion into the PPy film can lead to an increase in the thermal stability and redox properties of the PPy film. The PPy film doped with both CSA and molybdate anion displayed excellent anti-corrosion ability for CT3 mild steel in comparison with the PPy film and PPy film doped with only CSA or molybdate anion. Furthermore, the salt spray test was also carried out to more effectively evaluate the corrosion protection of doped PPy film for mild steel.

Flat slab structures are prone to progressive collapse due to their relatively heavy self-weight and susceptibility to punching shear failure. In this study, three one-third scaled slab–column sub-assemblages were statically and dynamically tested to examine the collapse behaviour of such structures when either an edge or a penultimate column is removed. In the static tests, the development of an alternative load path bridging over the removed column was investigated with two specimens that were loaded to failure by a load-control procedure using concrete weights. In the dynamic test, a specimen that had been loaded by concrete weight up to 80% of the yield-line capacity was subjected to a sudden column removal, which was simulated by a quick-release mechanism. Based on the experimental observations, the potential failure modes of flat slab structures, the development of tensile membrane action as an alternative load path, and the dynamic effects resulting from sudden column removal are discussed.

Background. Left ventricular systolic dysfunction (LVSD) is common in sepsis. Speckle-tracking echocardiography (STE) is a useful emerging tool for evaluating the intrinsic left ventricular systolic function. High-sensitivity cardiac troponin T (hs-cTnT) is the most sensitive biomarker of myocardial injury. However, there are limited data regarding the association between hs-cTnT level and left ventricular systolic dysfunction based on STE in septic patients. We performed this prospective study to evaluate the diagnostic value of hs-cTnT level for subclinical left ventricular systolic dysfunction measured by STE in septic patients according to the sepsis-3 definition. Methods. Patients with sepsis based on sepsis-3 definition admitted to the intensive care unit were prospectively performed STE and hs-cTnT level within 24 hours after the onset of sepsis. Baseline clinical and echocardiographic variables were collected. Left ventricular systolic dysfunction was defined as a global longitudinal strain of ≥−15%. Results. During a 19-month period, 116 patients were enrolled in the study. The elevated hs-cTnT level was seen in 86.2% of septic patients, and 43.1% of patients had LVSD on STE. The median hs-cTnT level and the proportion of elevated hs-cTnT level (>14 ng/L) were significantly higher in patients with LVSD than in patients without LVSD. The area under the ROC curves of hs-cTnT to detect LVSD was 0.73 ( P P = 0.025) and septic shock (HR, 7.6; 95% CI, 2.25 to 25.76; P = 0.001) were independent predictors of LVSD. Conclusion. Our study indicated that the serum hs-cTnT level might be a useful biomarker for detecting LVSD in septic patients.

Polypyrrole (PPy) was prepared on the mild steel substrate by electrochemical polymerisation in the solution containing pyrrole monomer and succinic acid. The mild steel surface could be passivated...

The conductive properties of polypyrrole chains doped with ClO

The work proposed here is devoted to the prediction and the characterization of the mechanical behavior of interlock woven composite structures. We propose an approach to characterize the mechanical properties of interlock woven composite structures and particularly to solve the problems associated with the creation of these complex geometries and their discretization into a conform mesh. One of the difficulties of this meso-macro approach is to reproduce faithfully the geometry of these architectures with complex shapes and to obtain a Representative Volume Element (RVE). Once this complex step is achieved, the mechanical properties of the composite can be thereafter obtained by homogenization from a finite element analysis. The difficulties to generate a RVE of such structures are well known: interpenetration and contacts between yarns, meshing of thin resin layers at interfaces, determination of the orientation of the fibers at all points of the structure. We propose an approach which consists of creating a geometric model of the yarns limiting or controlling the intersections and the contacts, defining a periodic RVE, meshing this RVE by tetrahedral with compatible meshes at the interfaces. Once the model is meshed and the symmetry conditions are defined, the properties are obtained by homogenization. The finite element calculations are performed on the ABAQUS software. Complex weaves can be automatically processed with this technique. The results are compared whit other modeling from the literature and with experimental data.; Ces travaux se placent dans le cadre de l'étude des propriétés mécaniques des architectures à renforcement tridimensionnel dans les structures composites. Nous proposons une approche permettant de caractériser les propriétés mécaniques de structures composites Interlock et en particulier de résoudre les problèmes liés à la création de ces géométries complexes et leur discrétisation.Une des difficultés des approches méso-macro réside dans la manière de reproduire de façon fidèle la géométrie de ces architectures aux formes très complexes et d'obtenir en particulier un Volume Elémentaire Représentatif (VER) duquel on peut déduire par calcul éléments finis les propriétés mécaniques par homogénéisation. Cette pluralité des formes engendre des difficultés de mise en œuvre essentiellement géométriques et des difficultés de maillage bien connues : interpénétration et contact des mèches, maillage de fines couches de résines aux interfaces, détermination en tout point de l'orientation des fibres. Nous proposons une approche qui consiste à créer un modèle géométrique des mèches limitant ou contrôlant les intersections et les contacts, à définir un VER périodique et à mailler ce VER en tétraèdres avec des maillages conformes aux interfaces. Une fois le modèle maillé obtenu et les conditions de périodicités définies, les propriétés mécaniques effectives sont obtenues par homogénéisation. Les calculs par éléments finis sont réalisés avec le logiciel ABAQUS. Les tissages complexes ont été traités automatiquement avec cette technique. Les résultats sont confrontés à ceux d’autres modélisations, issus de la littérature et de l’expérience.

The work proposed here is devoted to the prediction and the characterization of the mechanical behavior of interlock woven composite structures. We propose an approach to characterize the mechanical properties of interlock woven composite structures and particularly to solve the problems associated with the creation of these complex geometries and their discretization into a conform mesh. One of the difficulties of this meso-macro approach is to reproduce faithfully the geometry of these architectures with complex shapes and to obtain a Representative Volume Element (RVE). Once this complex step is achieved, the mechanical properties of the composite can be thereafter obtained by homogenization from a finite element analysis. The difficulties to generate a RVE of such structures are well known: interpenetration and contacts between yarns, meshing of thin resin layers at interfaces, determination of the orientation of the fibers at all points of the structure. We propose an approach which consists of creating a geometric model of the yarns limiting or controlling the intersections and the contacts, defining a periodic RVE, meshing this RVE by tetrahedral with compatible meshes at the interfaces. Once the model is meshed and the symmetry conditions are defined, the properties are obtained by homogenization. The finite element calculations are performed on the ABAQUS software. Complex weaves can be automatically processed with this technique. The results are compared whit other modeling from the literature and with experimental data.; Ces travaux se placent dans le cadre de l'étude des propriétés mécaniques des architectures à renforcement tridimensionnel dans les structures composites. Nous proposons une approche permettant de caractériser les propriétés mécaniques de structures composites Interlock et en particulier de résoudre les problèmes liés à la création de ces géométries complexes et leur discrétisation.Une des difficultés des approches méso-macro réside dans la manière de reproduire de façon fidèle la géométrie de ces architectures aux formes très complexes et d'obtenir en particulier un Volume Elémentaire Représentatif (VER) duquel on peut déduire par calcul éléments finis les propriétés mécaniques par homogénéisation. Cette pluralité des formes engendre des difficultés de mise en œuvre essentiellement géométriques et des difficultés de maillage bien connues : interpénétration et contact des mèches, maillage de fines couches de résines aux interfaces, détermination en tout point de l'orientation des fibres. Nous proposons une approche qui consiste à créer un modèle géométrique des mèches limitant ou contrôlant les intersections et les contacts, à définir un VER périodique et à mailler ce VER en tétraèdres avec des maillages conformes aux interfaces. Une fois le modèle maillé obtenu et les conditions de périodicités définies, les propriétés mécaniques effectives sont obtenues par homogénéisation. Les calculs par éléments finis sont réalisés avec le logiciel ABAQUS. Les tissages complexes ont été traités automatiquement avec cette technique. Les résultats sont confrontés à ceux d’autres modélisations, issus de la littérature et de l’expérience.