Development and human performance evaluation of a ground vehicle robotic force-feedback tele-operation system

ABSTRACT DEVELOPMENT AND HUMAN PERFORMANCE EVALUATION OF A GROUND VEHICLE ROBOTIC FORCE-FEEDBACK TELE-OPERATION SYSTEM by ANKUR SARAF May 2011 Advisor: Dr. Abhilash K. Pandya. Major: Electrical Engineering. Degree: Master of Science. Modern tele-operation systems are trying to take into account haptic and audio information in addition to visual data to provide as feedback to the tele-operator.This research emphasizes on the development of hardware and software architecture to enhance the tele-operation capabilities of omni-directional inspection robot (ODIS). The system enhances the tele-operation capabilities by introducing force-feedback to the tele-operators. The conventional joystick is replaced with Novint Falcon haptic joystick which gets the feedback from the wireless accelerometer sensor module mounted on the top of ODIS. The wireless accelerometer sensor module uses XBee modules for sending the acceleration data to the server. The server in-turn is connected to the joystick which is used to direct the ODIS. The advantage of the wireless accelerometer system is it can be used not only with ODIS but with any other unmanned vehicle as well. Though this research uses ODIS robot as the platform, the ideas and concepts put forward are applicable to tele-operation of robots in general

Picomolar Detection Of Hydrogen Peroxide Using Enzyme-Free Inorganic Nanoparticle-Based Sensor

A philosophical shift has occurred in the field of biomedical sciences from treatment of late-stage disease symptoms to early detection and prevention. Ceria nanoparticles (CNPs) have been demonstrated to neutralize free radical chemical species associated with many life-threatening disease states such as cancers and neurodegenerative diseases by undergoing redox changes (Ce3+ ↔ Ce4+). Herein, we investigate the electrochemical response of multi-valent CNPs in presence of hydrogen peroxide and demonstrate an enzyme-free CNP-based biosensor capable of ultra-low (limit of quantitation: 0.1 pM) detection. Several preparations of CNPs with varying Ce3+:Ce4+ are produced and are analyzed by electrochemical methods. We find that an increasing magnitude of response in cyclic voltammetry and chronoamperometry correlates with increasing Ce4+ relative to Ce3+ and utilize this finding in the design of the sensor platform. The sensor retains sensitivity across a range of pH\u27s and temperatures, wherein enzyme-based sensors will not function, and in blood serum: Reflecting selectivity and robustness as a potential implantable biomedical device

Functional Nial-Graphene Oxide Composite As A Model Coating For Aerospace Component Repair

Metallic plasma sprayed coatings are widely used in the aerospace industry to repair engine components. However, the inherent defects in coatings limit such repairs and reduce the service life of the parts. In this study, to improve the serviceability and mechanical properties of plasma sprayed coatings, multi-layered graphene oxide (GO) have been introduced as a reinforcement. The novelty of this work lies in the processing of the plasma sprayed, GO-reinforced metallic composite coatings. Commercially available Ni-Al powders were used with GO reinforcement, resulting in an increase in the mechanical properties. Retention of the GO was made successful by installing a customized inert argon shroud to prevent the combustion of GO. The HRTEM image confirms a homogenous distribution of GO within the metallic matrix. We report an improvement in hardness and tensile adhesion strength, and a reduction in residual strain and the coefficient of friction. The results presented in this article prove that GO can successfully be retained as an additive in thermal spray coatings and provide opportunities for low-cost manufacturing or repair

Modulating the Catalytic Activity of Cerium Oxide Nanoparticles with the Anion of the Precursor Salt

In this work, we tested our hypothesis that surface chemistry and antioxidant properties of cerium nanoparticles (CNPs) are affected by the presence of counterions. We first employed various precursor cerium­(III) (Ce­(III)) salts with different counterions (acetate, nitrate, chloride, and sulfate) to synthesize CNPs following the same wet chemical methodology. Electron spin resonance (ESR) studies provided evidence for the formation of radicals from counterions (e.g., NO₃^•²^– from reduction of NO₃^– in CNPs synthesized from Ce­(III) nitrate). Physicochemical properties of these CNPs, e.g., dispersion stability, hydrodynamic size, signature surface chemistry, superoxide dismutase (SOD)-mimetic activity, and oxidation potentials, were found to be significantly affected by the anions of the precursor salts. CNPs synthesized from Ce­(III) nitrate and Ce­(III) chloride exhibited higher extent of SOD-mimetic activities. Therefore, these CNPs were studied extensively employing in situ ultraviolet (UV)–visible spectroelectrochemistry and changing the counterion concentrations affecting the oxidation potentials of these CNPs. Thus, the physicochemical and antioxidant properties of CNPs can be modulated by anions of the precursor. Furthermore, our ESR studies present evidence of the formation of guanine cation radical (G^•⁺) in 5′-dGMP via UV-photoionization at 77 K in the presence of CNPs synthesized from Ce­(III) nitrate and chloride, and CNPs act as the scavenger of radiation-produced electrons

Acute-on-chronic liver failure: consensus recommendations of the Asian Pacific association for the study of the liver (APASL): an update (vol 13, pg 353, 2019)

10.1007/s12072-019-09980-1HEPATOLOGY INTERNATIONAL136826-82

Acute-on-chronic liver failure: consensus recommendations of the Asian Pacific association for the study of the liver (APASL): an update

10.1007/s12072-019-09946-3HEPATOLOGY INTERNATIONAL134353-39