200 research outputs found

    Instabilities and waves in thin films of living fluids

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    We formulate the thin-film hydrodynamics of a suspension of polar self-driven particles and show that it is prone to several instabilities through the interplay of activity, polarity and the existence of a free surface. Our approach extends, to self-propelling systems, the work of Ben Amar and Cummings [Phys Fluids 13 (2001) 1160] on thin-film nematics. Based on our estimates the instabilities should be seen in bacterial suspensions and the lamellipodium, and are potentially relevant to the morphology of biofilms. We suggest several experimental tests of our theory.Comment: 4 pages, pdflatex, accepted for publication in Phys Rev Let

    QUALITY BY DESIGN-BASED OPTIMIZATION AND VALIDATION OF NEW REVERSE PHASE-HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY METHOD FOR SIMULTANEOUS ESTIMATION OF LEVOFLOXACIN HEMIHYDRATE AND AMBROXOL HYDROCHLORIDE IN BULK AND ITS PHARMACEUTICAL DOSAGE FORM

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    ABSTRACTObjective: Innovative application of quality by design (QbD) technique for simultaneous estimation of levofloxacin and ambroxol hydrochloride (HCL)in bulk and its pharmaceutical dosage form using reverse phase-high-performance liquid chromatography (RP-HPLC) method.Method: A method has been developed for the separation of levofloxacin and ambroxol HCL using RP-HPLC on C18 column (250 4.6 mm, 5 ml) withultraviolet detection at 306 nm. Experimental designs were applied for multivariate optimization of the experimental conditions of RP-HPLC method.Three independent factors: Acetonitrile content in the mobile phase composition, buffer pH, and flow rate were used to design mathematical models.Here, central composite design (CCD) experimental design was used to study the response surface technique and to study in depth the effects ofthese independent factors. Derringer's desirability function was applied to simultaneously optimize the retention time of last eluting peak (ambroxolhydrochloride) and resolution between levofloxacin and ambroxol hydrochloride.Result and Discussion: The predicted optimum assay condition consisted of acetonitrile, potassium dihydrogen phosphate buffer (pH 5.00;potassium dihydrogen phosphate), and methanol in a proportion of 20:70:10% v/v, respectively, as the mobile phase at a flow rate of 1.2 ml/minute.Using this optimum condition, baseline separation of both drugs with good resolution and a run time of <5 minutes were achieved. The optimizedassay condition was validated according to the ICH guidelines to confirm specificity, linearity, accuracy, and precision.Keywords: Levofloxacin, Ambroxol hydrochloride, Experimental design, Response surface methodology, Derringer's desirability, Quality by designapproach

    ANALYITCAL METHOD DEVELOPMENT AND VALIDATION OF A REVERSED-PHASE HIGHPERFORMANCE LIQUID CHROMATOGRAPHY FOR THE DETERMINATION OF MODAFINIL IN BULK AND PHARMACEUTICAL DOSAGE FORMS

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    Objective: To development and validation of a reversed-phase high-performance liquid chromatography (RP-HPLC) for the determination of modafinil in bulk and pharmaceutical dosage forms.Methods: A simple, precise, rapid, and accurate RP-HPLC method was developed for the estimation of modafinil in bulk and pharmaceutical dosageforms. Xterra RP 18 (250 mm × 4.6 mm, 5 μ particle size) with a mobile phase consisting of methanol:water 70:30 V/V was used. The flow rate1.0 ml/min and the effluents were monitored at 260 nm. The retention time and recovery time was 12 minutes. The detector response was linear inthe concentration of 10-50 μg/ml. The respective linear regression equation being Y=452.1x+65237. The limit of detection and limit of quantificationwere 4.547 and 1.377 mcg, respectively. The method was validated by determining its accuracy, precision, and system suitability.Result: The objective of the present work is to develop simple, precise, and reliable HPLC method for the analysis of modafinil in bulk andpharmaceutical dosage forms. This is achieved using the most commonly employed Xterra RP 18 (250 mm × 4.6 mm, 5 μ particle size) columndetection at 260 nm. The present method was validated according to ICH guidelines.Conclusion: In this study, a simple, fast and reliable HPLC method was developed and validated for the determination of modafinil in pharmaceuticalformulations.Keywords: Modafinil, Reversed-phase high-performance liquid chromatography, Estimation, ICH guidelines, Tablets

    IoT Based Industrial Production Monitoring System Using Wireless Sensor Networks

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    The objective of the work is to monitoring the production lines in industry using wireless sensor networks. This work presents the benefits of an automated data collection and display system for production lines. It involves wireless sensor networks for monitoring the productions in industry. Condition monitoring reduces human inspection requirements through automated monitoring, reduces maintenance through detecting faults before they escalate and improves safety and reliability. This work can monitor productions using temperature, voltage and current sensors with support of microcontroller. The relay is acts like a switch to monitor the production lines. In this work, Global System for Mobile communication technique is used to transferring the collected data. The collection of data, it is transferred into computerize spreadsheet in the remote office by authorized personnel for reporting purpose. The system will generate an automated report which stays in place and the management only needs to act base on the results. This work is cost effective automatic data collection is the alternative to manual data collection. It significantly improves the accuracy of the valuable reports for the management. It also reduces the time for identifying the fault using this techniqu

    Review on Computational Electromagnetics

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    Computational electromagnetics (CEM) is applied to model the interaction of electromagnetic fields with the objects like antenna, waveguides, aircraft and their environment using Maxwell equations.  In this paper the strength and weakness of various computational electromagnetic techniques are discussed. Performance of various techniques in terms accuracy, memory and computational time for application specific tasks such as modeling RCS (Radar cross section), space applications, thin wires, antenna arrays are presented in this paper

    Integrated energy planning: Part II. Examples of DEFENDUS scenarios

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    The first part of this paper presented an ab initio exposition of the development-focused end-use oriented service-directed (DEFENDUS) approach to energy planning. In this approach, the future demand for any source of energy is estimated on the basis of the energy services required and the efficiency with which these are provided. To meet this demand, the costs per unit of the available energy-supply/saving technologies are estimated and a least-cost mix of options identified. In this second part, some of the energy studies for which the DEFENDUS method has been used are described to demonstrate that its applicability is not confined to a particular region or source of energy. These studies include: electricity for five states of India, petroleum products for the country as a whole, biomass for the state of Karnataka, and a composite energy scenario for Karnataka involving integration of all the currently-used sources of energy. In every case, the energy usage pattern in the commencement year of the plan, i.e., the total energy usage disaggregated between the existing categories of users according to their end-uses, is obtained. Then, depending on the goals selected and the strategies that could be adopted to achieve them, growth rates for each category of users are used to estimate the number of users in future years. Improvement in the efficiency of end-use devices and/or substitution of energy sources are considered, to determine the possible reduction in the category-wise unit energy usage, and the corresponding energy requirement is estimated. The electricity plan for the state of Karnataka comprises future demand estimation as well as the comparative costs of various supply/saving options. For the other states, electricity demand has been estimated in various scenarios. In the oil scenarios for India, the focus is mainly on demand management through modal and carrier shifts, with emphasis on the middle distillates. The biomass strategy for Karnataka includes both demand- and supply-side measures. All these studies show that the DEFENDUS planning procedure is easily amenable to modification according to the particular case under consideration. Further, the integration of worksheets for individual sources of energy demonstrates that this method, though simple, is capable of dealing with composite energy planning. Above all, with the popularity of personal computers and spreadsheet packages, the DEFENDUS method facilitates the democratization of energy planning

    Self-organized Pattern Formation in Motor-Microtubule Mixtures

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    We propose and study a hydrodynamic model for pattern formation in mixtures of molecular motors and microtubules. The steady state patterns we obtain in different regimes of parameter space include arrangements of vortices and asters separately as well as aster-vortex mixtures and fully disordered states. Such stable steady states are observed in experiments in vitro. The sequence of patterns obtained in the experiments can be associated with smooth trajectories in a non-equilibrium phase diagram for our model.Comment: 11 pages Latex file, 2 figures include

    Determinants of Kangaroo Mother Care uptake for small babies along the health facility to community continuum in Karnataka, India

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