558 research outputs found

    Hydrodynamic signatures of stationary Marangoni-driven surfactant transport

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    We experimentally study steady Marangoni-driven surfactant transport on the interface of a deep water layer. Using hydrodynamic measurements, and without using any knowledge of the surfactant physico-chemical properties, we show that sodium dodecyl sulphate and Tergitol 15-S-9 introduced in low concentrations result in a flow driven by adsorbed surfactant. At higher surfactant concentration, the flow is dominated by the dissolved surfactant. Using Camphoric acid, whose properties are {\it a priori} unknown, we demonstrate this method's efficacy by showing its spreading is adsorption dominated

    Rate-distortion function for finite block codes: Analysis of symmetric binary hamming problem

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    Shannon's rate-distortion theory provides an asymptotic analysis, where delays are allowed to grow unbounded. In practice, real-time applications, such as video streaming and network storage, are subject to certain maximum delay. Accordingly, it is imperative to develop a finite-delay framework for analyzing the rate-distortion limit. In this backdrop, we propose an intuitive generalization of Shannon's asymptotic operational framework to finite block codes. In view of the extreme complexity of such framework, we obtain insight by specializing to the symmetric binary hamming problem. Even upon such specialization, the proposed framework is computationally so intensive that accurate evaluation of the finite-delay rate-distortion function is practical only upto a block length of three. In order to obtain further insight, we then propose a lower-complexity lower bound, based on the partition function of natural numbers, whose computation is practical upto a block length of six. Finally, using a simple combinatorial argument, we propose an upper bound to localize the desired rate-distortion function between our lower and upper bounds

    Peripartum cardiomyopathy with a history of doxorubicin therapy: case report & review of literature

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    Background: Peripartum cardiomyopathy and doxorubicin-induced cardiomyopathy are well described conditions but there is little description in the literature of both occurring together. Case: A 29 year old G1P0 with a remote history of childhood chondroblastic osteosarcoma treated with high-dose doxorubicin therapy who developed minimally symptomatic cardiomyopathy during her pregnancy with ejection fraction reaching as low as 20-30%. She delivered via primary low-transverse cesarean section at 37 weeks complicated by uterine atony with an unremarkable recovery. Cardiomyopathy was treated with metoprolol and enalapril and she achieved ejection fraction of 44% at one year follow-up with complete return to baseline activity. Discussion: We present a woman with a history of doxorubicin therapy who developed peripartum cardiomyopathy and recovered symptomatically after one year. Although treatment of peripartum cardiomyopathy regardless of etiology is well-defined, there are few reports and no standard guidelines for special considerations in pregnant women with a history of doxorubicin therapy, a topic that may warrant further investigation

    Peripartum cardiomyopathy with a history of doxorubicin therapy: case report & review of literature

    Get PDF
    Background: Peripartum cardiomyopathy and doxorubicin-induced cardiomyopathy are well described conditions but there is little description in the literature of both occurring together. Case: A 29 year old G1P0 with a remote history of childhood chondroblastic osteosarcoma treated with high-dose doxorubicin therapy who developed minimally symptomatic cardiomyopathy during her pregnancy with ejection fraction reaching as low as 20-30%. She delivered via primary low-transverse cesarean section at 37 weeks complicated by uterine atony with an unremarkable recovery. Cardiomyopathy was treated with metoprolol and enalapril and she achieved ejection fraction of 44% at one year follow-up with complete return to baseline activity. Discussion: We present a woman with a history of doxorubicin therapy who developed peripartum cardiomyopathy and recovered symptomatically after one year. Although treatment of peripartum cardiomyopathy regardless of etiology is well-defined, there are few reports and no standard guidelines for special considerations in pregnant women with a history of doxorubicin therapy, a topic that may warrant further investigation

    Force Distributions in Frictional Granular Media

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    We report a joint experimental and theoretical investigation of the probability distribution functions (pdf's) of the normal and tangential (frictional) forces in amorphous frictional media. We consider both the joint pdf of normal and tangential forces together, and the marginal pdf's of normal forces separately and tangential forces separately. A maximum entropy formalism is utilized for all these cases after identifying the appropriate constraints. Excellent agreements with both experimental and simulational data are reported. The proposed joint pdf (which appears new to the literature) predicts giant slip events at low pressures, again in agreement with observations.Comment: 13 pages, 15 figure

    Precision Attitude Stabilization with Intermittent External Torque

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    The attitude stabilization of a micro-satellite employing a variable-amplitude cold gas thruster which reflects as a time varying gain on the control input is considered. Existing literature uses a persistence filter based approach that typically leads to large control gains and torque inputs during specific time intervals corresponding to the 'on' phase of the external actuation. This work aims at reducing the transient spikes placed upon the torque commands by the judicious introduction of an additional time varying scaling signal as part of the control law. The time update mechanism for the new scaling factor and overall closed-loop stability are established through a Lyapunov-like analysis. Numerical simulations highlight the various features of this new control algorithm for spacecraft attitude stabilization subject to torque intermittence.Comment: Presented as paper AAS 21-402 at the 31st AAS/AIAA Space Flight Mechanics Meeting, Virtual, February 1-4 202

    Integrated Alternative Source of Energy System with Grid Substation

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    This paper discusses the modeling, simulation and optimization of integrated alternative source of energy system with grid substation. When there is a lack of energy in grid substation to meet the demand of customer load then alternative source of energy compensates energy deficiency and after that if there is excess energy available then remaining energy is stored in battery bank or sells to grid according to need. In another case when required energy is not generated by alternative sources then remaining energy is purchased from the grid and if the grid substation hasn't available these remaining energy to meet the customer load demand during the peak load then stored battery energy is also active. The size of integrated alternative source of energy system may vary from few hundred watts to ten or hundreds of MW. The possible sources of alternative energy like solar, wind and biomass are considered under this paper. Study location, Muzaffarpur district of Bihar (India), is taken because there is good potential of energy generation from alternative source of energy and still there is no any wind and solar energy power plant. The modeling and simulation of the system is done by using HOMER software and the software solve the optimization problem to minimize the total cost of system and maximum utilization of alternative source of energy

    A Novel approach for Agrobacterium-mediated germ line transformation of Indian Bread wheat (Triticum aestivum) and Pasta wheat (Triticum durum)

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    Recalcitrance of wheat towards tissue culture procedures has hampered the wide use of conventional transformation techniques for its improvement. In the present study, a novel, non-tissue culture, cost effective approach has been established for the introduction of transgenes in wheat. Dry, mature seeds of two Indian varieties of wheat, Triticum aestivum cv. HD2329 (bread wheat), and Triticum durum cv. PDW215 (pasta wheat), were co-cultivated with Agrobacterium strain GV2260 (p35SGUSINT) and LBA4404 (pCAMBIA 3301), respectively, in the presence of 200 μM acetosyringone. The plantlets testing gus positive were raised till maturity in garden pots. T0 lines were screened by PCR for presence of selectable markers in the transformed plants followed by confirmation with Southern hybridization. In bread wheat, nptII was detected in five primary transformed lines (T0) (ws1, ws2, ws3, ws4, ws5) and the bar gene in three putatively transformed durum wheat lines (wsb1, wsb2, wsb3). The transformation efficiency was calculated as 1.16%, and 0.84% for T. aestivum and T. durum, respectively.Â

    Intelligent recognition of colorectal cancer combining application of computer-assisted diagnosis with deep learning approaches

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    The malignancy of the colorectal testing methods has been exposed triumph to decrease the occurrence and death rate; this cancer is the relatively sluggish rising and has an extremely peculiar to develop the premalignant lesions. Now, many patients are not going to colorectal cancer screening, and people who do, are able to diagnose existing tests and screening methods. The most important concept of this motivation for this research idea is to evaluate the recognized data from the immediately available colorectal cancer screening methods. The data provided to laboratory technologists is important in the formulation of appropriate recommendations that will reduce colorectal cancer. With all standard colon cancer tests can be recognized agitatedly, the treatment of colorectal cancer is more efficient. The intelligent computer assisted diagnosis (CAD) is the most powerful technique for recognition of colorectal cancer in recent advances. It is a lot to reduce the level of interference nature has contributed considerably to the advancement of the quality of cancer treatment. To enhance diagnostic accuracy intelligent CAD has a research always active, ongoing with the deep learning and machine learning approaches with the associated convolutional neural network (CNN) scheme
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