Energy transfers and magnetic energy growth in small-scale dynamo

In this letter we investigate the dynamics of magnetic energy growth in small-scale dynamo by studying energy transfers, mainly energy fluxes and shell-to-shell energy transfers. We perform dynamo simulations for magnetic Prandtl number $\mathrm{Pm}=20$ on $1024^3$ grid using pseudospectral method. We demonstrate that the magnetic energy growth is caused by nonlocal energy transfers from the large-scale or forcing-scale velocity field to small-scale magnetic field. The peak of these energy transfers move towards lower wavenumbers as dynamo evolves, which is the reason why the integral scale of the magnetic field increases with time. The energy transfers $U2U$ (velocity to velocity) and $B2B$ (magnetic to magnetic) are forward and local.Comment: 6 pages, 8 figure

Novel flow apparatus for investigating shear-enhanced crystallization and structure development in semicrystalline polymers

An instrument to study the effects of shearing on the crystallization process in semicrystalline polymers is described. It can impose transient stresses similar to those encountered in polymer processing and provides in situ monitoring of microstructure development during and after cessation of flow. Box-like wall shear stress profiles (rise and fall times under 50 ms with maximum wall shear stress on the order of 0.1 MPa) can be applied for controlled durations. A unique feature of our device is that it accommodates a wide variety of real-time probes of structure such as visible and infrared polarimetry and light and x-ray scattering measurements. The design also allows us to retrieve the sample for ex situ optical and electron microscopy. Data are acquired with millisecond resolution enabling us to record the extent of shear deformation of the polymer melt during the pressure pulse. Our device works with small sample quantities (as little as 5 g; each experiment takes ~ 500 mg) as opposed to the kilogram quantities required by previous instruments capable of imposing comparable deformations. This orders-of-magnitude reduction in the sample size allows us to study model polymers and new developmental resins, both of which are typically available only in gram-scale quantities. The compact design of the shear cell makes it possible to transport it to synchrotron light sources for in situ x-ray scattering studies of the evolution of the crystalline structure. Thus, our device is a valuable new tool that can be used to evaluate the crystallization characteristics of resins with experimental compositions or molecular architectures when subjected to processing-like flow conditions. We demonstrate some of the features of this device by presenting selected results on isotactic polypropylenes

Emergence of resistance to linezolid in methicillin resistant Staphylococcus haemolyticus reported from the sub Himalayan region of India

The spread of resistance among coagulase negative Staphylococci against major drugs is alarming as it limits the treatment options for serious infections. Resistance to linezolid in these organisms is emerging and further compounded by being observed in multidrug resistant strains. It is the only antibiotic available as an oral formulation for resistant Staphylococcal infections and due to the presence of a novel structure and unique mechanism of action, it does not display cross resistance with other classes of antimicrobial agents. However, the widespread use of Linezolid has gradually turned the impending fear of emergence of resistance against this novel drug into a reality. Herein we report a case of sepsis due to methicillin resistant Staphylococcus haemolyticus in a 16-year-old male child found resistant to linezolid, rarely reported from Sub Himalayan region of Indian sub-continent

Mapping the Indian Contribution in Pathogen Research during 2008-2017: A Scientometric Analysis

The present study mainly examines the growth rate of publications in the field of Pathogen research in India during the period of 2008-2017. The study based on Scopus databases and using scientometric tools. It reveals that a total 13070 of publications were published from the marked period of study. our analysis includes the year wise publications output, annual growth rate, compound annual growth rate, relative growth rate and doubling time, most productive authors, documents wise distribution of publications etc., and found that the maximum 1925 (14.73%) of research papers were published in the year 2016, followed by 1896 (14.51%) of publication in 2017. The maximum 36.541 annual growth rate was recorded in the year 2011, and 0.1189 CAGR was recorded in the year 2009. The maximum RGR 0.82 was recorded in the year 2009, and the highest doubling time 4.414 was recorded in the year 2017. The highest 69 publications were contributed by Dhama, K. and the maximum 10909 documents were ‘Article’ type

A Novel Approach to Extract Morphological Variables in Crystalline Polymers from Time-Resolved Synchrotron SAXS Data

A novel approach to extract morphological variables in crystalline polymers from time-resolved SAXS data using the method of correlation and interface distribution functions has been devised. The principle of the calculation is based on two alternative expressions of Porod's law using the form of the interference function. The approach enables the continuous estimate of the Porod constant, and corrections for liquid scattering and finite interface between the two phases, from the time-resolved data. A model of lamellar morphology has been implemented to interpret the calculated correlation and interface distribution functions. Many detailed morphological variables such as lamellar long period, thicknesses of crystal and amorphous phases, interface thickness, and scattering invariant can be estimated. An example analysis of isothermal crystallization in PET measured by synchrotron SAXS is demonstrated