Remote-Controlled Ambidextrous Robot Hand Concept

In the development of robotic limbs, the side of members is of importance to define the shape of artificial limbs and the range of movements. It is mainly significant tbr biomedical applications concerning patients suffering arms or legs injuries, fn this paper, the concept of an ambidextrous design lbr robot hands is introduced. The fingers can curl in one xvay or another, to imitate either a right hand or a left hand. The advantages and inconveniences of different models have been investigated to optimise the range and the maximum force applied by fingers. Besides, a remote control interthce is integrated to the system, allowing both to send comrnands through internet and to display a video streaming of the ambidextrous hand as feedback. Therefore, a robotic prosthesis could be used for the first time in telerehabilitation. The main application areas targeted are physiotherapy alter strokes or management of phantom pains/br amputees by/earning to control the ambidextrous hand. A client application is also accessible on Facehook social network, making the robotic limb easily reachable for the patients. Additionally the ambidextrous hand can be used tbr robotics research as well as artistic performances.     

Failure analysis of air pre-heater tubes of a petrochemicals plant

Heat resistant alloy tubes used in the higher temperature range of 1150–1273 K depends on the protective scale integrity for prevention of corrosion induced premature failures in a mixed gas environment with potential corrodents for oxidation, carburization and sulphidation attack. Cast HK40+Nb alloy tubes of an air pre-heater unit of a petrochemical industry failed prematurely after 13,000 h in service. The unit used smoke gas containing gaseous corrodents that could cause oxidation/sulphidation/carburization type of attack. Failed parts showed crack/punctures below the corrosion product filled pits. The crack occurred in the fully carburized zone present at the thinned out centre of the pit. Factors like excessive temperature cycling, overheating, presence of impurities either in the pre-heating gas mixture or that got introduced while in operation were found to be the reasons for breach of protective scale integrity leading to unwarranted corrosion attack resulting in thinning of tube material and internal corrosion penetration which finally led to premature failure.     

Biosorptive removal of cationic dye from aqueous system: a response surface methodological approach

In this study, response surface methodology (RSM) was employed for the removal of methylene blue (MB) from aqueous solution using neem (Azadirachta indica) bark dust (NBD) as a bioadsorbent. The influence of various process parameters namely initial concentration (500–1,000 mg L^?1), bioadsorbent dose [0.20–1.50 g (100 mL)^?1], pH (5–12), and stirring rate (250–650 rpm) was taken as an input parameter. A total of 29 biosorption experimental runs were carried out employing the detailed conditions designed by RSM based on the Box–Behnken design (BBD). Response surface plots were studied to determine the interaction effects of main factors and optimum conditions of process. Regression analysis showed good fit of the experimental data to the second-order polynomial model with coefficient of determination (R ²) value of 0.9760 and model F value of 40.68. The predicted R ² value is 0.8979. In addition, results reported in this research demonstrated the feasibility of employing NBD as bioadsorbent for MB removal.     

Scattering from finite by infinite arrays of slots in a thinconducting wedge

The radar scattering from a finite by infinite array of slots cut into a thin conducting wedge is considered. The wedge is formed by taking a thin ground plane and applying a bend to create a sharp edge which is parallel to the columns of slots in the infinite axis. Results are derived for thin linear slots whose major axes are either parallel or perpendicular to the edge. A hybrid moment method and geometrical theory of diffraction approach is used, with magnetic current expansion functions defined using Floquet's theorem on single columns of slots. Predictions generally agree with scattering measurements of finite by finite array physical models with monostatic patterns taken in a plane orthogonal to the sharp edge     

Design and analysis of MEMS based piezoelectric energy harvester for machine monitoring application

Microsystem Technologies - In this paper a new structure of MEMS based piezoelectric (PZ) energy harvester with resonant frequency of 100 Hz is proposed which can be integrated with...     

Electromagnetic forward and inverse scattering analysis of a one‐dimensional collision system

A one‐dimensional electromagnetic scattering analysis in presence of a colliding system is presented. A detailed analysis of higher order Doppler effect, due to multiple electromagnetic field reflection upon the two moving objects is performed, invoking the center of momentum frame and taking all possible range of velocity into account. A quasi‐stationary based finite difference time domain numerical method is then performed in order to test the proposed mathematical model for forward scattering analysis. Further, a spectral‐temporal mathematical derivation is performed for the inverse scattering analysis to compute the spatial and temporal information of the target system.     

Quad notch UWB antenna using combination of slots and split‐ring resonator

A novel coplanar waveguide fed UWB antenna with quad notch band characteristics has been proposed in this work. The antenna layout is designed based on a combination of well‐known geometrical shapes: a half ellipse patch, rectangle, and triangle. The shape of the ground plane is partially tapered rectangular. The overall dimension of the antenna is 41.5 × 32 mm. The antenna uses three U‐shaped slots at the top surface to create three notched band characteristics. A split‐ring resonator is then introduced at the bottom surface of the antenna. With the integration of split‐ring resonator at the bottom surface, an additional notch band at 7.25 to 7.75 (6.7%) GHz is created in the antenna. The designed antenna has an operating impedance bandwidth (VSWR ≤2) ranges from 3.03 to 12.34 GHz except in quad frequency stop bands of 3.3 to 3.7 (11.4%), 5.15 to 5.35 (3.8%), 5.725 to 5.825 (1.7%), and 7.25 to 7.75 (6.7%) GHz. The proposed antennas are successfully designed, prototyped, and measured. The simulated and measured results are extensively studied and discussed. Correlation between the time‐domain transmitting antenna input signal and the received antenna output signal is calculated in order to ensure that the proposed antenna can be used in pulse‐communication systems. This antenna finds applications in medical imaging, military radar systems, and other common UWB applications.     

The Effect of Pitting on Fatigue Lives of Peak-Aged and Overaged 7075 Aluminum Alloys

Fatigue lives at high peak stresses for peak-aged (T6) and overaged (T73) 7075 aluminum alloy were compared in the uncorroded and precorroded (pitted) states. Absolute fatigue lives of T73 samples were much higher than that of T6 in the virgin as well as precorroded condition, but the normalized life of T73 was less than that of T6, indicating an intrinsic crack initiation resistance in the former, borne out by fractography, which showed that fatigue cracks almost always initiated at pits for T73 but not for T6. The various crack initiation methodologies observed and the effect of pitting on fatigue lives in the two aging conditions are discussed.