Trends in Cardiac Pacemaker Batteries

Batteries used in Implantable cardiac pacemakers-present unique challenges to their developers and manufacturers in terms of high levels of safety and reliability. In addition, the batteries must have longevity to avoid frequent replacements. Technological advances in leads/electrodes have reduced energy requirements by two orders of magnitude. Micro-electronics advances sharply reduce internal current drain concurrently decreasing size and increasing functionality, reliability, and longevity. It is reported that about 600,000 pacemakers are implanted each year worldwide and the total number of people with various types of implanted pacemaker has already crossed 3 million. A cardiac pacemaker uses half of its battery power for cardiac stimulation and the other half for housekeeping tasks such as monitoring and data logging. The first implanted cardiac pacemaker used nickel-cadmium rechargeable battery, later on zinc-mercury battery was developed and used which lasted for over 2 years. Lithium iodine battery invented and used by Wilson Greatbatch and his team in 1972 made the real impact to implantable cardiac pacemakers. This battery lasts for about 10 years and even today is the power source for many manufacturers of cardiac pacemakers. This paper briefly reviews various developments of battery technologies since the inception of cardiac pacemaker and presents the alternative to lithium iodine battery for the near future

Microstructure and Mechanical Properties of Laser Beam Welds of 15CDV6 Steel

The present study is concerned with laser beam welding of 15CDV6 steel, that is in the hardened (quenched and tempered) condition before welding. Autogenously butt-welded joints are made using carbon dioxide laser with a maximum output of 3.5 kw in the continuous wave mode. Weld microstructure, microhardness measurement across the weldment, transverse tensile properties, and room temperature impact properties of the weldment have been evaluated. The fusion zone exhibits a epitaxial grain growth. The microstrutural features of heat-affected zone and fusion zone vary, due to different thermal cycles for which these were subjected during welding. The average weld metal hardness was 480 Hv. The observed hardness distribution across the welds were correlated with the microstructures. The welds exhibited lower toughness of 50 joules as compared to parent metal of 55 joules and the tensile strength values of the welded specimens are close to that obtained for sheet specimens.Defence Science Journal, Vol. 65, No. 4, July 2015, pp. 339-342, DOI: http://dx.doi.org/10.14429/dsj.65.874

X-Ray Peak Broadening Analysis and Optical Studies of ZnO Nanoparticles Derived by Surfactant Assisted Combustion Synthesis

In this paper, synthesis of ZnO nanoparticles is done by a simple and facile surfactant assisted combustion synthesis. The synthesis of ZnO nanoparticles has been prepared using Zinc nitrate as a precursor material, glycine as a fuel with the support of non-ionic surfactant TWEEN 80. The obtained ZnO nanoparticles have been studied using characterization techniques like X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), and UV-Vis Spectroscopy. XRD results reveal that the sample is crystalline with a hexagonal wurtzite phase. X-ray peak broadening analysis was used to evaluate the crystallite sizes and lattice strain by the Williamson-Hall (W-H) analysis. Further appropriate physical parameters such as strain, stress, and energy density values were also calculated using W-H analysis with different models, viz, uniform deformation model, uniform deformation stress model and uniform deformation energy density model. Transmission electron microscopy (TEM) result reveals that the ZnO nanoparticles sample is spherical in shape showing particle sizes less than 40 nm. The optical properties of ZnO nanoparticles were studied by UV-Vis spectroscopy. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3102

A comparative study of the consistent and simplified finite element analyses of Eigenvalue, problems

Classical displacement method of the finite element analysis of eigenvalue problems requires the use of consistent and conforming elements. However, simpler approaches based on relaxing the condition of consistency of the element descriptions, such as lumped inertia force method and others are also found to yield satisfactory results. In this paper we make a comparative study of the consistent and simplified approaches with reference to four representative problems. In the simplified approach studied in this paper, the contribution of straining modes in the derivation of the mass and geometric stiffness matrices is neglected and this simplifies their derivation substantially. The results indicate that this simplification introduces only small errors in the eigenvalues

Assessment of accuracies of finite eigenvalues

This article does not have an abstract

A Numerical Study of Penetration in Concrete Targets by Eroding Projectiles of Different Materials

Numerical simulations have been performed to examine the effect of three different eroding rod materials on the penetration in concrete targets. Same kinetic energy is delivered to concrete target using cylindrical rods of Aluminium, Iron, and Copper of identical size. Impact velocities have been varied to keep the kinetic energy the same. Penetration characteristics like centerline interface velocity, penetrator deceleration, plastic strain in the target, and energy partitioning during penetration have been studied for the three different penetrator materials. In all three cases, penetration proceeds nearly hydrodynamically. It is seen that even though the steady-state penetration ceases before reaching the hydrodynamic limit, the secondary penetration takes the total penetration beyond the hydrodynamic value. Plastic strain in the target material is a measure of damage beyond the crater produced by penetration. The lateral extent of plastic strain in target is more for Aluminium penetrator compared to the other two. Energy partitioning during penetration provides details of the rate at which energy is entering into the target. Kinetic energy delivered to the target during impact is partitioned into internal energy and kinetic energy of the target. Finally, the influence of target thickness on the extent of plastic strain has been studied. The result shows that Aluminium penetrators inflict maximum damage to targets of finite thickness

MOBILE ROBOT SELF-PLANNING AND NAVIGATION BASED ON ARTIFICIAL LANDMARK LOCALIZATION METHOD AND BINOCULAR STEREO VISION

This paper describes design of artificial landmark based on colour model used for Self-planning in unstructured environment to a robot for its movement. This method provides less error in estimation when compared to existing methods. This project is an investigation into building a system which visually detects artificial landmarks to determine the landmarks within a location, decipher their position within that location and track the landmark throughout the location using Binocular stereo vision

Antihepatotoxic effect of Elephantopus scaber L. on carbon tetrachloride-induced hepatotoxicity in rats

Elephantopus scaber was used in folk medicine in several countries to treat different diseases. Liver diseases are major World wise health Problems. The Present aim of the study was evaluate The Antihepatotoxic effects of different fractions of Elephantopus scaber against Carbon tetrachloride (CCl4) induced hepatic damage in Rats. All the fractions were given orally in different doses (125mg/kg, 250mg/kg, 500mg/kg). The Antihepatotoxic effect was assessed by measuring serum parameters like  aspertate transaminase (AST), alanine transaminase (ALT), Alkaline Phospatase (ALP) and total bilurubin.  All the fractions of Elephantopus scaber showed Antihepatotoxic effect.The ethanol fraction was shows significant percentage protection than compared to other fractions. Therefore, our study supports the isolation and use of active constituents from Ethanol fraction of Elephantopus scaber in treating of liver disease

Effect of Explosive Shapes (in Sand Buried Condition) on the Failure of a Circular Clamped Plate of Protective Vehicle

Protective vehicles like armoured personnel carriers (APCs) require assessment of failure of structural elements subjected to impulsive load resulting from explosive blast under sand buried conditions. The explosive shape and location of detonation affect the failure in near field region. In the present study, a circular clamped Rolled Homogenous Armour (RHA) steel plate has been modelled using JC strength & damage model and explosive using JWL equation. Initially, the reflected pressure and specific impulse for a fixed quantity of explosive (3.75 kg) of various shapes i.e. sphere, hemisphere, cylinders with Length to Diameter (L/D) ratio varying from 0.1 to 1 were studied for sand buried at a standoff distance of 118.1 mm. Further, studies were extended for cylindrical charges of φ 213.77 mm with conical 120°-150° and hemispherical cavities with radius of R1.2-R1.8. It was observed that, reflected pressure and specific impulse is much higher for hemispherical cavity of R1.2. The permanent deformation obtained using non-dimensional impulse is valid for explosives without cavities. However, the cavity charges produce failure of plate in the central region of the charge. The critical impulse emerges as an important parameter for assessing failure due to cavity charges. In addition, the scale down experiment is conducted to validate the effectiveness of cavity charges. It can be concluded that cavity charge with hemispherical radius of R1.2 can provide highest damage to RHA plates in close standoff distance