2,096 research outputs found
Selection of Dominant Characteristic Modes
The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The theory of characteristic modes is a popular
physics based deterministic approach which has found several recent
applications in the fields of radiator design, electromagnetic
interference modelling and radiated emission analysis. The modal
theory is based on the approximation of the total induced current
in an electromagnetic structure in terms of a weighted sum of
multiple characteristic current modes. The resultant outgoing
field is also a weighted summation of the characteristic field
patterns. Henceforth, a proper modal measure is an essential
requirement to identify the modes which play a dominant role
for a frequency of interest. The existing literature of significance
measures restricts itself for ideal lossless structures only. This
paper explores the pros and cons of the existing measures and
correspondingly suggests suitable alternatives for both radiating
and scattering applications. An example is presented in order
to illustrate the proposed modal method for approximating the
shielding response of a slotted geometry
Robustness of d-Density Wave Order to Nonmagnetic Impurities
Effect of finite density of nonmagnetic impurities on a coexisting phase of
d-density wave (DDW) order and d-wave superconducting (DSC) order is studied
using Bogoliubov-de Gennes (BdG) method. The spatial variation of the
inhomogeneous DDW order due to impurities has a strong correlation with that of
density, which is very different from that of DSC order. The length scale
associated with DDW is found to be of the order of a lattice spacing. The
nontrivial inhomogeneities are shown to make DDW order much more robust to the
impurities, while DSC order becomes very sensitive to them. The effect of
disorder on the density of states is also discussed.Comment: 4 pages, 3 PostScript figure
Impact of disorder on unconventional superconductors with competing ground states
Non-magnetic impurities are known as strong pair breakers in superconductors
with pure d-wave pairing symmetry. Here we discuss d-wave states under the
combined influence of impurities and competing instabilities, such as pairing
in a secondary channel as well as lattice symmetry breaking. Using the
self-consistent T-matrix formalism, we show that disorder can strongly modify
the competition between different pairing states. For a d-wave superconductor
in the presence of a subdominant local attraction, Anderson's theorem implies
that disorder always generates an s-wave component in the gap at sufficiently
low temperature, even if a pure d_{x^2-y^2} order parameter characterizes the
clean system. In contrast, disorder is always detrimental to an additional
d_{xy} component. This qualitative difference suggests that disorder can be
used to discriminate among different mixed-gap structures in high-temperature
superconductors. We also investigate superconducting phases with lattice
symmetry breaking in the form of bond order, and show that the addition of
impurities quickly leads to the restoration of translation invariance. Our
results highlight the importance of controlling disorder for the observation of
competing order parameters in cuprates.Comment: 13 pages, 10 figure
System level simulation for femtocellular networks
© 2014 IEEE. LTE is an emerging wireless data communication technology to provide broadband ubiquitous Internet access. Femtocells are included in 3GPP since Release 8 to enhance the indoor network coverage and capacity. System level simulation is used for performance evaluation of LTE-Femtocellular networks. Research works on performance optimization could not be justified since there was no common reference simulator to do so until the inception of LTE-Sim. The simulation scenarios for Femtocells in LTE-Sim encompasses two-tier macro-femto scenario but to the best of our knowledge there is no published work on coding and scripting of femtocell scenario in LTE-Sim. In this paper, the development of a femtocell scenario is discussed with simulation outcomes
Enhanced photocatalytic and antibacterial activity of plasma-reduced silver nanoparticles
A non-thermal atmospheric pressure plasma jet has been used for the green synthesis of highly dispersed colloidal silver nanoparticles. The reducing species such as hydrogen radicals and hydrated electrons are identified, and the change in the solution pH is studied during AgNP formation. The structural properties and size of the plasma-reduced silver nanoparticles are characterized via X-ray diffraction, ultraviolet-visible spectroscopy, fluorescence spectroscopy and transmission electron microscopy. The size of the colloidal AgNPs is tuned by adjusting the initial concentration of AgNO3. The effect of terephthalic acid, a hydroxyl radical scavenger, on the reduction of Ag+ ion is studied. The typical catalytic activity data indicate the better performance of the plasma-reduced colloidal Ag nanoparticles than that obtained from the chemical reduction method. The antibacterial activity of the plasma-reduced Ag nanoparticles also shows a better performance than that of the chemically reduced AgNPs, highlighting the potential of the plasma reduction approach for the synthesis of metal nanoparticles, which are stable even after 30 days without a stabilizing agent. Additionally, the effects of hydroxyl scavengers (isopropyl alcohol) and Fenton's reagent (Fe2+ salt) on CV degradation are studied
A comparative study of total body fat percentage, visceral fat percentage and whole body subcutaneous and skeletal fat percentage between patients with depression and normal subjects
Background: In today’s world, depression has been named as the foremost public health problem while obesity has reached epidemic proportions in India in the 21st century. A probable association between depression and obesity has been suspected. The quantification of obesity, can be done by various methods such as body mass index (BMI), bioelectrical impedance analysis (BIA) etc. Among these, BMI and BIA have emerged as well accepted techniques. From impedance measurement values and other data such as a person’s height, weight and body types, it is possible to calculate the percentage of body fat, fat-free mass (skeletal muscles), and other body composition values.
Methods: This was an analytical cross-sectional study. Cases comprised of subjects who were diagnosed with depression but were ‘drug naive’ while the control group comprised of age-matched subjects drawn from the normal population. Measurement of various anthropometric parameters like BMI, total body fat (TBF) %, visceral fat % etc. was carried out among the cases and controls using a portable body fat monitor scan that employed BIA.
Results: BMI, TBF%, visceral fat %, whole body subcutaneous and skeletal fat % were found to be much higher among the cases (subjects with depression) in comparison with the controls (normal subjects), in a statistically significant way.
Conclusions: The study showed that the intrinsic inflammatory potential of obesity coupled with its probable dysregulatory impact on the (hypothalamo-pituitary-adrenal) HPA axis was possibly the underlying cause of the elevated anthropometric parameters noted among the cases
Unveiling Novel insights in healthcare through exploring knowledge, Attitude, and practice (KAP) toward Covid-19: A Cross sectional study among Nepalese College students
Purpose: The goal of this study was to evaluate the COVID-19 knowledge, attitude, and practise of college students in Lalitpur, Nepal, and to investigate how these factors relate to sociodemo graphic factors. Design/Methodology/Approach: College students were surveyed through questionnaire to learn more about their understanding, attitudes, and COVID-19-related behaviours. Binary logistic regression was used to examine the association between these variables. Findings: The survey found that a fair amount of people had a general understanding of COVID-19 symptoms (29.32%), whereas a smaller number had a good understanding of preventive actions (16.42%). It was discovered that students' knowledge of COVID-19 was highly influenced by income, education, and age. The majority of those surveyed (82.11%) thought that following preventive guidelines was very helpful in limiting the spread of the virus. Students' perceptions towards COVID-19 were found to be highly influenced by their age, education, and income. A considerable percentage of the students avoided large gatherings in practise (88.26%), showing the influence of age, education, income, and occupation on preventive practises. However, there was no discernible connection between marital status and COVID-19 preventive strategies. Originality/Value: This study advances knowledge of college students' beliefs, practises, and knowledge of COVID-19. In order to effectively stop the virus from spreading among college students, it emphasises the significance of focused interventions and educational campaigns that emphasise knowledge enhancement, the promotion of preventative measures, and consideration of socio-demographic factors
Combustion synthesized TiO2 for enhanced photocatalytic activity under the direct sunlight-optimization of titanylnitrate synthesis
Optimized synthesis of Ti-precursor ‘titanylnitrate’ for one step combustion synthesis of N- and C-doped TiO2 catalysts were reported and characterized by using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), diffused reflectance UV–vis spectroscopy, N2 adsorption and X-ray photoelectron spectroscopy (XPS). XRD confirmed the formation of TiO2 anatase and nano-crystallite size which was further confirmed by TEM. UV-DRS confirmed the decrease in the band gap to less than 3.0 eV, which was assigned due to the presence of C and N in the framework of TiO2 as confirmed by X-ray photoelectron spectroscopy. Degradation of methylene blue in aqueous solution under the direct sunlight was carried out and typical results indicated the better performance of the synthesized catalysts than Degussa P-25
Effect of Mn Concentration on Magneto-mechnaical Properties in Directionally Solidified Ferromagnetic Shape Memory Ni-Mn-Ga Alloys
Heusler type alloys Ni50Mn25+xGa25-x (x=2,3,4 and 5) based on near stoichiometric Ni2MnGa compositions were directionally solidified using modified Bridgman method. The alloys thus prepared were characterized for their chemical composition, crystal structure, microstructure, phase transformation, magnetic and magneto-mechanical properties. The directionally solidified Ni50Mn30Ga20 alloy rod exhibited maximum magnetocrystalline value of 95 kJm-3 and lowest detwinning stresses for martensite phase of about 5MPa. The reversible room temperature magnetic field induced strain of 0.2% under external magnetic field of 0.6T and 0.05kN bias load was obtained for the directionally solidified Ni50Mn30Ga20 alloy
Interaction Effects in the Mesoscopic Regime: A Quantum Monte Carlo Study of Irregular Quantum Dots
We address the issue of accurately treating interaction effects in the
mesoscopic regime by investigating the ground state properties of isolated
irregular quantum dots. Quantum Monte Carlo techniques are used to calculate
the distributions of ground state spin and addition energy. We find a reduced
probability of high spin and a somewhat larger even/odd alternation in the
addition energy from quantum Monte Carlo than in local spin density functional
theory. In both approaches, the even/odd effect gets smaller with increasing
number of electrons, contrary to the theoretical understanding of large dots.
We argue that the local spin density approximation over predicts the effects of
interactions in quantum dots.Comment: Final Version, to appear in PRB as a Rapid Com
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