618 research outputs found

    Trends in Cardiac Pacemaker Batteries

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    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

    A new analytical method for determination of ledipasvir and sofosbuvir in pharmaceutical formulations by HPLC method

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    A simple, Accurate, precise method was developed for the simultaneous estimation of the Sofosbuvir and Ledipasvir in Tablet dosage form. Chromatogram was run through Std Discovery C8 150 x 4.6 mm, 5m. Mobile phase containing Buffer 0.1% OPA: Acetonitrile taken in the ratio 60:40 was pumped through column at a flow rate of 1 ml/min. Buffer used in this method was 0.1% OPA buffer. Temperature was maintained at 30°C. Optimized wavelength selected was 260 nm. Retention time of Sofosbuvir and Ledipasvir were found to be 2.367 min and 3.436 min. %RSD of the Sofosbuvir and Ledipasvir were and found to be 0.6 and 0.5 respectively. %Recovery was obtained as 99.61% and 99.80% for Sofosbuvir and Ledipasvir respectively. LOD, LOQ values obtained from regression equations of Sofosbuvir and Ledipasvir were 0.67, 2.02 and 0.70, 2.12 respectively. Regression equation of Sofosbuvir is y = 4266.x + 7700, and y = 4861.x + 2656.of Ledipasvir. Retention times were decreased and run time was decreased, so the method developed was simple and economical that can be adopted in regular Quality control test in Industries

    A new analytical method for determination of dolutegravir and rilpivirine in pharmaceutical formulations by RP-HPLC method

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    A simple, rapid, precise, sensitive and reproducible reverse phase high performance liquid chromatography (RP-HPLC) method has been developed for the quantitative analysis of Dolutegravir and Rilpivirine in pharmaceutical dosage form. Chromatographic separation of Dolutegravir and Rilpivirine was achieved on Waters Alliance -2695, by using Luna C18 (250mm x 4.6mm, 5µm) column and the mobile phase containing 0.1% OPA & ACN in the ratio of 50:50 v/v. The flow rate was 1.0 ml/min, detection was carried out by absorption at 245 nm using a photodiode array detector at ambient temperature. The number of theoretical plates and tailing factor for Dolutegravir and Rilpivirine were NLT 2000 and should not more than 2 respectively. The linearity of the method was excellent over the concentration range 10-150 µg/ml and 5-75 µg/ml for Dolutegravir and Rilpivirine respectively. The correlation coefficient was 0.999. % Relative standard deviation of peak areas of all measurements always less than 2.0. The proposed method was validated according to ICH guidelines. The method was found to be simple, economical, suitable, precise, accurate & robust method for quantitative analysis of Dolutegravir and Rilpivirine study of its stability

    Invention into the AC Voltage Regulator with V/F Technique for Induction Motor Starting Applications

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    Modern electrical motors are available in many different forms with different mounting arrangements. To ensure a long life for the motor it is important to select it with correct degree of protection when operating under heavy duty conditions in a severe environment. Smooth starting is also one of major considerations to get long life and optimum efficiency. The conventional method to start an asynchronous motor with a soft starter is by reducing the voltage of the motor by varying the voltage “off time”. The “off time” could for example be controlled to achieve a desired maximum current level or a constant driving torque.  Even if the voltage is reduced the fundamental frequency of the voltage is equal to the supply voltage frequency. That gives a large difference between angular speed of supply voltage and angular speed of the rotor during start. Due to the large difference in angular speed the motor flux will be low and thereby also the ability to produce torque. Instead of using the conventional control method with a reduced voltage it is possible to use a method with controlled flux similar to frequency inverters for soft-starters. As the soft-starter does not have the intermediate DC energy storage the applied voltage vector has to be directly modulated from the mains supply

    Beneficiation studies on beach placer sample for steel making industries

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    Beneficiation studies were carried out on the Talashil beach placer sample of South Maharastra Coast, India. The sample contains magnetite, ilmenite, rutile, hematite, goethite and chromite as opaque minerals in the sample. The total heavy minerals fraction reaches 53.8 % by weight whereas the total magnetic minerals are 56.9%. It is observed that the 2nd stage DHIMS magnetic fraction contains 65.2 % Fe2O3 with an over all yield of 37.8 % and a 86 % recovery from a containing 26.8 % Fe2O3 feed. This product can be used in the pellet feed for steel making after suitable blending with high-grade iron ore fines

    Adaptive Estimation of Line-of-sight Rate Measurement from a Radio Frequency Seeker

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    The line-of-sight (LOS) rate output from a radio frequency (RF) seeker is widely used during the homing phase guidance of a tactical missile: The LOS rate is noisy and needs to be filtered.The application of an adaptive Kalman filter for the L.OS rate state estimation has been studied. This filter requires minimal a priori knowledge about technical parameters of the seeker. It isalso capable of estimating the variable noise statistics

    DEVELOPMENT OF CIRCUIT FOR STANDALONE SOLAR PV HYBRID SYSTEM

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    A control rule for a standalone star electrical phenomenon (PV)-the diesel-battery hybrid system is enforced during this paper. The planned system deals with the intermittent nature of the energy generated by the PV array and it conjointly provides power quality improvement. The PV array is integrated through a dc– dc boost converter and is controlled employing the most powerful point pursuit rule to get the most power underneath varying in operation conditions. The battery energy storage system (BESS) is integrated into the ICE generator set for the coordinated load management and power flow inside the system. The admittance-based management rule is employed for load equalization, harmonics elimination, and reactive power compensation underneath three-phase four-wire linear and nonlinear hundreds. A four-leg voltage-source converter with BESS conjointly provides neutral current compensation. The performance of the planned stand-alone hybrid system is studied underneath completely different loading conditions through an experiment on a developed epitome of the system
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