Optimization and design of a cable driven upper arm exoskeleton

This paper presents the design of a wearable upper arm exoskeleton that can be used to assist and train arm movements of stroke survivors or subjects with weak musculature. In the last ten years, a number of upper-arm training devices have emerged. However, due to their size and weight, their use is restricted to clinics and research laboratories. Our proposed wearable exoskeleton builds upon our extensive research experience in wire driven manipulators and design of rehabilitative systems. The exoskeleton consists of three main parts: (i) an inverted U-shaped cuff that rests on the shoulder, (ii) a cuff on the upper arm, and (iii) a cuff on the forearm. Six motors, mounted on the shoulder cuff, drive the cuffs on the upper arm and forearm, using cables. In order to assess the performance of this exoskeleton, prior to use on humans, a laboratory test-bed has been developed where this exoskeleton is mounted on a model skeleton, instrumented with sensors to measure joint angles and transmitted forces to the shoulder. This paper describes design details of the exoskeleton and addresses the key issue of parameter optimization to achieve useful workspace based on kinematic and kinetic models.</jats:p

Low temperature method for synthesis of MgNb2O6 and its characterization

There are various methods for synthesizing luminescent semi-conductor nano-particles.&nbsp; A sample at chemical root of low temperature method was used to synthesize the magnesium niobate (MgNb2O6) nano-particles by using Niobium pentaoxide (Nb2O5), Magnesium nitrate, Ammonium carbonate were used.&nbsp; All chemicals was taken A.R. Grade (99.99%).&nbsp; Ammonium carbonate and Ammonium hydroxide was used to precipitate magnesium carbonate as Mg2+ cation and Niobium hydroxide as a Nb5+ cations under basic conditions.&nbsp; This precipitate was heating at 800&deg;C it produced MgNb2O6 fine powders.&nbsp; The lattice parameters were studied by least square method and obtained a = 5.687 A&deg;, b = 13.975 A&deg; and C = 4.938 A&deg;.&nbsp; The average particle size of MgNb2O6 were studied by Scaning Electron Microscope (SEM) and found to be 45 nm.&nbsp; The crystallite size calculated from Scherrer's formula

Effect of post-irradiation deformation on the tl of Cu++ doped nacl crystals

The effect of post, irradiation deformation on the TL of &gamma;-irradiated undoped and Cu++ doped NaCl crystals for different impurity concentrations and radiation doses have been studied. In the case of post-irradiation deformation, the two TL peak are found for &gamma;-irradiated undoped and Cu++ doped NaCl crystals at 393ï‚°K and 464ï‚°K respectively. The intensity of both the peak decreases with increasing post-irradiation deformation of the crystals, however, the peak temperatures Tm1 and Tm2 do not change in the post-irradiations deformation of the crystals. There is no occurrence of post-irradiation deformation generated new TL peak in Cu++ doped NaCl crystals. The deformation bleaching as well as enhanced number of the compatible electron traps are responsible for the effect of post-irradiation deformation on the TL of crystals

Tensor weight structures and t-structures on derived categories of Noetherian schemes

We give a condition which characterises those weight structures on a derived category which come from a Thomason filtration on the underlying scheme. Weight structures satisfying our condition will be called $\otimes ^c$-weight structures. More precisely, for a Noetherian separated scheme $X$, we give a bijection between the set of compactly generated $\otimes ^c$-weight structures on $\mathbf{D} (\mathrm{Qcoh\hspace{1mm}}X)$ and the set of Thomason filtrations of $X$. We achieve this classification in two steps. First, we show that the bijection of S\v{t}ov\'{\i}\v{c}ek and Posp\'{\i}\v{s}il restricts to give a bijection between the set of compactly generated $\otimes ^c$-weight structures and the set of compactly generated tensor t-structures. We then use our earlier classification of compactly generated tensor t-structures to obtain the desired result. We also study some immediate consequences of these classifications in the particular case of the projective line. We show that in contrast to the case of tensor t-structures, there are no non-trivial tensor weight structures on $\mathbf{D}^b (\mathrm{Coh \hspace{1mm}} \mathbb{P}^1_k)$.Comment: 11 pages, comments are welcome

Hardware in the Loop Simulation and Control Design for Autonomous Free Running Ship Models

This paper presents an hardware-in-the-loop (HIL) simulation system tool to test and validate an autonomous free running model system for ship hydrodynamic studies with a view to verification of the code, the control logic and system peripherals. The computer simulation of the plant model in real-time computer does not require the actual physical system and reduces the development cost and time for control design and testing purposes. The HIL system includes: the actual programmable embedded controller along with peripherals and a plant model virtually simulated in a real-time computer. With regard to ship controller design for ship model testing, this study describes a plant model for surge and a Nomoto first order steering dynamics, both implemented using Simulink software suit. The surge model captures a quasi-steady state relationship between surge speed and the propeller rpms, obtained from simple forward speed towing tank tests or derived analytically. The Nomoto first order steering dynamics is obtained by performing the standard turning circle test at model scale. The control logic obtained is embedded in a NI-cRIO based controller. The surge and steering dynamics models are used to design a proportional-derivative controller and an LQR controller. The controller runs a Linux based real-time operating system programmed using LabVIEW software. The HIL simulation tool allows for the emulation of standard ship hydrodynamic tests consisting of straight line, turning circle and zigzag to validate the combined system performance, prior to actual for use in the autonomous free-running tests

Study of serum calcium and serum magnesium levels in newly diagnosed hypertensives

Background: In normal vascular tissue physiology, calcium plays a crucial role. Calcium and magnesium metabolism have been implicated in the pathogenesis of primary hypertension. The present study aimed to assess serum calcium and serum magnesium levels and to study the association of the serum magnesium and serum calcium levels with hypertension in newly diagnosed hypertensive patients of Bikaner, Rajasthan. Methods: This cross- sectional study was carried out on 60 subjects aged between 18 years to 60 years in the department of physiology and in association with department of medicine and department of cardiology, S. P. Medical College and associated group of hospitals, Bikaner. Data was compiled and entered into Microsoft software statistical package for the social sciences (SPSS) version 22.0. Data was summarised as frequencies, mean and standard deviations. For continuous data the means were compared between cases and controls using unpaired or independent t test; and for nominal data, chi-square or Fisher’s exact tests were applied to compare frequency distribution between cases and controls to see the statistical significance. Results: The present study shows statistically insignificant change in serum calcium and serum magnesium levels in newly detected hypertensive patients when compared to normotensive controls. Conclusions: In view of statistically insignificant change in serum calcium and magnesium levels in newly detected hypertensive patients in our study, further studies with a large sample size and more uniform population are required to find if any significant association exists between these cations and hypertension