Today, fresh water resources are reached by pollution, in particular the organic pollutants. Recent studies reveal the presence of various toxic substances, such as pesticides and textile colorants, in surface or underground waters everywhere in the world. Among these products, we are interested in two pesticides, the paraquat (PQ) and diquat (DQ) as well as a textile colorant: methylene blue (BM). The treatment of these pollutants requires in addition to the usual treatments (coagulation-flocculation, decantation, filtration, oxidation…), a stage of refining by adsorption on activated carbon. These processes remain hard and expensive. In this respect, this actual work depends on the elimination of the PQ, the DQ and the BM, by adsorption on natural polymeric chitin, which is a principal structural constituent of the protective cuticles shellfish, insects and also of the cellular walls of certain mushrooms and micro-organisms. This material is chosen because of on one hand its great abundance in Morocco, and on the other hand, its structural and textural properties, allowing its use in the treatment of polluted water. Chitin were extracted primarily from Moroccan exoskeleton shellfish. Characterization of chitin was performed by infrared spectroscopy and nuclear magnetic resonance. The adsorption of PQ, DQ and BM by chitin was studied at different pH values, the pollutants-adsorbent contact time and initial pollutants concentration. The adsorption is described by both Langmuir-type isotherm and Freundlich-type isotherm.

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“Assist as needed” control algorithms promote activity of patients during robotic gait training. Implementing these requires a free walking mode of a device, as unassisted motions should not be hindered. The goal of this study was to assess the normality of walking in the free walking mode of the LOPES gait trainer, an 8 degrees-of-freedom lightweight impedance controlledexoskeleton. Kinematics, gait parameters and muscle activity of walking in a free walking mode in the device were compared with those of walking freely on a treadmill. Average values and variability of the spatio-temporal gait variables showed no or small (relative to cycle-to-cycle variability) changes and the kinematics showed a significant and relevant decrease in knee angle range only. Muscles involved in push off showed a small decrease, whereas muscles involved in acceleration and deceleration of the swing leg showed an increase of their activity. Timing of the activity was mainly unaffected. Most of the observed differences could be ascribed to the inertia of the exoskeleton. Overall, walking with the LOPES resembled free walking, although this required several adaptations in muscle activity. These adaptations are such that we expect that Assist as Needed training can be implemented in LOPES.

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This study presents a three control degrees of freedom myoelectric control scheme that employs an independent signal for thumb flexion intended to allow for multiple gripping patterns. This scheme is designed to work with an adaptive grasp prosthesis designed in a parallel study. The control scheme is designed and employed using LabVIEW 8.2®. Human subject testing is conducted to evaluate functionality, perceived ease of learning, and perceived ease of control for both genders. Testing indicated that independent control of thumb flexion and generating DC motor drive signals for multiple grips was possible (success rate ≥83%). A visual analog scale score of 9.28/10 indicated that the system and the program user interface were very easy to learn. A visual analog scale score of 6.3/10 indicated that the system was fairly easy to control. A marginally significant difference (p = 0.057) was observed between genders, where females perceived the system to be easier to control than males.

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This paper proposes a knee joint moment estimating algorithm which utilizes the surface EMGs of involved muscles and joint angle kinematic data. This algorithm will be essential part for the control system design of exoskeletal robotic devices. In order for this algorithm to accurately predict joint moments, it is necessary to know the one’s musculo-skeletal properties, which is virtually impossible. An optimization process is used to determine one’s musculo-tendon characteristics. The proposed method is evaluated through the comparison with the isokinetic experimental results. Based on the analysis on this comparison, it is claimed that the gravity compensation data of the dynamometer (CON-TREX MJ system) contains not only purely gravity compensated portion but also the knee joint moment contributed by the passive muscle fiber forces.

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Neurological injuries caused by stroke, spinal cord injury or other illnesses and accidents often lead to walking disabilities. If not properly treated, gait disorders can lead to impaired physical and mental health, reduced physical activity, falls, fear of falling, loss of independence and the need for continuous medical care. After an accident or the start of an illness it is important to start the patient’s gait rehabilitation process as soon as mental and physical conditions allow. Robotized rehabilitation systems have a number of potential benefits over traditional manual rehabilitation. These benefits include an increase in the effectiveness of the rehabilitation process, reduced costs of rehabilitation and reduced need for trained medical personnel. This paper presents details of the development of the concept of a mobile gait rehabilitation system consisting of a mobile base and powered exoskeleton. In particular, modeling and simulation of its mechanical system are considered. The presented simulation results demonstrate the need for including actuated translational degrees of freedom between the support platform and the exoskeleton to allow displacement of patient’s pelvis and practice of dynamically balanced walking.

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