Removal of Solophenyl Red 3BL Dye from Textile Effluents by Adsorption Using a Natural Adsorbent Oxalis pes-caprae L.

The aim of the present study was to assess the adsorption potential of a natural adsorbent Oxalis pes-caprae L. for the removal of azo-dye solophenyl red 3BL (SR 3BL) from textile effluents. The adsorbent was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The effect of various parameters on the efficiency of the adsorption was studied. The optimum was found with the contact time of 35 minutes, pH of 6, and temperature of 25 °C. The equilibrium experimental data were fitted with the Langmuir, Freundlich, and Temkin models. Experimental data were well described with the Langmuir isotherm indicating monolayer adsorption. Pseudo-first-order, pseudo-second-order, and Elovich kinetic models were used to evaluate the adsorption kinetics. The adsorption kinetics was found to follow closely the pseudo-first-order kinetic model. Thermodynamics studies revealed that the adsorption process was spontaneous and exothermic. This work is licensed under a Creative Commons Attribution 4.0 International License

Backstepping and Sliding-mode Techniques Applied to an Indoor Micro Quadrotor

The latest technological progress in sensors, actuators and energy storage devices enables the developments of miniature VTOL systems. In this paper we present the results of two nonlinear control techniques applied to an autonomous micro helicopter called Quadrotor. A backstepping and a sliding-mode techniques. We performed various simulations in open and closed loop and implemented several experiments on the test-bench to validate the control laws. Finally, we discuss the results of each approach. These developments are part of the OS4 project in our lab

Microstructure and mechanical behavior in dissimilar 13Cr/2205 stainless steel welded pipes

Thiswork aims to investigate the microstructure and themechanical behavior of dissimilar 13Cr Supermartensitic/2205 Duplex stainless steelwelded pipes. A wide variety ofmicrostructures resulting fromboth solidification and solid state transformation is induced by the fusion welding process across the weld joint. The tensile tests show that the deformation process of the dissimilarweld joint ismainly controlled by the two basematerials: the duplex steel at the beginning of the deformation and the supermartensitic one at its end. This is confirmed by the microtensile tests showing the overmatching effect of the weld metal. The fatigue tests conducted on dissimilar welded specimens led us to conclude that the weld metal is considered as a weak link of the weld joint in the high cycle fatigue regime. This is supported by its lower fatigue limit compared to the two basematerials that exhibit a similar fatigue behavio

Chemical recycling of poly(ethylene terephthalate). Application to the synthesis of multiblock copolyesters

The chemical recycling of the poly(ethylene terephthalate), (PET), has been successfully carried out by glycolysis in the presence of bis (2-hydroxyethyl) terephthalate (BHET) resulting in the formation of hydroxytelechelic oligomers. These oligomers were then treated with carboxytelechelic poly(ε-caprolactone) oligomers of Mn = 2300 and Mn = 730 g•mol–1 molecular weight, in the absence or presence of the titanium tetrabutyloxide (Ti(OBu)4) as a catalyst to get multiblock copolyesters. The chemical structure of the synthesized copolyesters was investigated by size exclusion chromatography (SEC) and proton Nuclear Magnetic Resonance (1H NMR) spectroscopy. Moreover the differential scanning calorimetry (DSC) was used to explore their thermal properties. The ester-ester interchange reaction was observed between the two oligopolyesters, was studied and discussed in detail

Design and Control of an Indoor Micro Quadrotor

Recent progress in sensor technology, data processing and integrated actuators has made the development of miniature flying robots fully possible. Micro VTOL1 systems represent a useful class of flying robots because of their strong capabilities for small-area monitoring and building exploration. In this paper we describe the approach that our lab2 has taken to micro VTOL evolving towards full autonomy, and present the mechanical design, dynamic modelling, sensing, and control of our indoor VTOL autonomous robot OS43

Towards Autonomous Indoor Micro VTOL

ISSN:0929-5593ISSN:1573-752

PID vs LQ Control Techniques Applied to an Indoor Micro Quadrotor

The development of miniature flying robots has become a reachable dream thanks to the new sensing and actuating technologies. Micro VTOL1 systems represent a useful class of flying robots because of their strong abilities for small-area monitoring and building exploration. In this paper, we present the results of two model-based control techniques applied to an autonomous four-rotor micro helicopter called Quadrotor. A classical approach (PID) assuming a simplified dynamics and a modern technique (LQ), based on a more complete model. Various simulations were performed and several tests on the bench validate the control laws. Finally, we present the results of the first test in flight with the helicopter released. These developments are part of the OS42 project in our lab3

Autonomous Navigation and Security: A 13000h/3000km Case Study

This paper presents the design of an autonomous mobile platform and its security system. The MB835 mobile platform has been adopted for RoboX, a fully autonomous tour guide robot. In 2002, 11 of these tour guides have served the Robotics exhibition at Expo.02 (Swiss National Exhibition) from May 15 to October 20. This project has been conjointly conducted by the Autonomous Systems Lab, Swiss Federal Institute of Technology Lausanne (EPFL) and BlueBotics SA the spin-off company of the lab, which has produced the robots. The goal was to maximize the autonomy and mobility of the platform while ensuring high performance, robustness and security. The paper presents the platform, its navigation and security, which resulted in the ANT product (Autonomous Navigation Technology) and the results of the Robotics exhibition as empirical validation of the whole system

SKY-SAILOR Design of an autonomous solar powered martian airplane

For more than two decades, Mars has been of great interest for scientific exploration, using orbiting spacecrafts or landers. Orbiters like Mars Express cover large areas and give images of the surface with a resolution limited to several meters. Rovers missions, like Pathfinder or MER, offer the ability to maneuver to scientifically interesting sites, perform analysis of soil and rock composition, but are limited in range to the immediate surroundings of the landing site. There is a strategic gap for systems that would combine high-resolution imagery and extensive coverage. This gap can be addressed by micro-airplanes that will give more accurate images than satellites, thanks to their proximity to the ground (about 0.5 to 2 km) and cover much larger areas than rovers without being limited by terrain roughness. This paper presents a feasibility study and the first design of a very lightweight solar powered airplane for Mars exploration. Called Sky-Sailor, it was investigated in an ESA definition study within the framework of the Startiger technology program