Meander Line EBG Based Multiband Antenna for WLAN and WiMAX application

There have been many investigations in the past regarding the design of multi- band antennas. A multiband antenna is the one in which the same antenna can be operated at different frequencies. There have been many approaches towards the design of the multiband antenna like stacked patches, parasitic patches, use of slots, shaping i.e., the use of notches, reactive loading, slot loaded patches etc. The use of slots is an easier approach towards the design of multiband an- tenna as there is a well defined theoretical approach towards the design of the slot antennas. These slots can be cut either in the patch or in the ground plane as needed for the application. Higher gain is an important requirement for an antenna and use of Electromagnetic Band-Gap structures(EBG) is one of the promising technique to achieve this. The present thesis work focuses on the design of multiband antenna as well as novel Electromagnetic Band-Gap structures and their integration for enhance- ment of the gain of the antenna at desired frequencies of operation. The multi- band antenna is designed by cutting slots in the ground plane and the Uniplanar EBG is employed for the gain enhancement. The Fractalized Meander Line EBG based Microstrip Patch Slot Antenna oper- ates in the 6-7 GHz (Extended C-Band) and has a fractional bandwidth of 13% , and it maintains the radiation characteristics in the desired band with gain rang- ing from 5.5 to 7 dB. The Meander Line EBG based Multiband Antenna operates in the WLAN and WiMAX bands at frequencies 2.4, 3.6, 5.2 GHz respectively having gain 3.5 , 4.2 and 6.19 d

Effect of foliar spray of elicitors on status of defense proteins in relation to mustard aphid infestation in crop Brassica cultivars

Mustard aphid, Lipaphis erysimi Kalt., is the key insect pest of crop Brassicas causing significant reduction in crop yield. In the present study, widely grown Brassica cultivars RLC-1 (Brassica juncea) and GSC-6 (Brassica napus) were treated with elicitors salicylic acid (SA) and jasmonic acid (JA) at 0.5mM and 1mM concentration via foliar spray (given at 40 and 60 days after planting (DAP). Their effect was evaluated in terms of total soluble protein content and activities of defense proteins (peroxidase, protease inhibitor, polyphenol oxidase, amylase inhibitor and lectins) in relation to aphid infestation in leaf tissue. SA and JA application caused significant increase in activities of defense proteins as well as total soluble proteins. JA at 1mM concentration was most effective in both Brassica cultivars. The 2nd foliar spray gave a booster response. The aphid population/plant reduced significantly in both the cultivars with JA as well as SA. POD and PPO registered negative correlation with aphid population count. SA and JA foliar applications seemed effective against mustard aphid through positive modulation in activities of defense proteins

Surface optical Raman modes in InN nanostructures

Raman spectroscopic investigations are carried out on one-dimensional nanostructures of InN,such as nanowires and nanobelts synthesized by chemical vapor deposition. In addition to the optical phonons allowed by symmetry; A1, E1 and E2(high) modes, two additional Raman peaks are observed around 528 cm-1 and 560 cm-1 for these nanostructures. Calculations for the frequencies of surface optical (SO) phonon modes in InN nanostructures yield values close to those of the new Raman modes. A possible reason for large intensities for SO modes in these nanostructures is also discussed.Comment: 13 pages, 4 figures, Submitted in Journa

Effect of Pre-Harvest Treatment on Yield, Maturity and Quality of Flame Seedless Grape (Vitis vinifera L.)

To improve fruit quality in grape cv. Flame Seedless, application of Ethephon (400 and 500 ppm) and trunk girdling was done at veraison stage. Cluster thinning was done by retaining 100, 75 and 50% of total number of bunches on the vines, and, the rest were removed immediately after full bloom. Highest yield was obtained in the treatment 100% Crop load + 500ppm Ethephon, followed by 75% Crop load + 500ppm Ethephon. The treatment of 50% Crop load + 500ppm Ethephon resulted in maximum bunch weight, lowest percentage of uneven coloured berries, maximum TSS, minimum acidity and maximum TSS:acid ratio, maximum anthocyanin content, advanced maturity by 9 days and had maximum sensory rating. But, in this treatment, yield was significantly lower than in treatments where either 75% or 100% Crop load was retained. Thus, considering yield as well as quality parameters, the treatment 75% Crop load + 500ppm Ethephon was found to be the best

Fourier PCA and Robust Tensor Decomposition

Fourier PCA is Principal Component Analysis of a matrix obtained from higher order derivatives of the logarithm of the Fourier transform of a distribution.We make this method algorithmic by developing a tensor decomposition method for a pair of tensors sharing the same vectors in rank-$1$ decompositions. Our main application is the first provably polynomial-time algorithm for underdetermined ICA, i.e., learning an $n \times m$ matrix $A$ from observations $y=Ax$ where $x$ is drawn from an unknown product distribution with arbitrary non-Gaussian components. The number of component distributions $m$ can be arbitrarily higher than the dimension $n$ and the columns of $A$ only need to satisfy a natural and efficiently verifiable nondegeneracy condition. As a second application, we give an alternative algorithm for learning mixtures of spherical Gaussians with linearly independent means. These results also hold in the presence of Gaussian noise.Comment: Extensively revised; details added; minor errors corrected; exposition improve

Confined Acoustic Phonon in CdS1-xSex Nanoparticles in Borosilicate Glass

We calculate low-frequency Raman scattering from the confined acoustic phonon modes of CdS1-xSex nanoparticles embedded in borosilicate glass. The calculation of the Raman scattering by acoustic phonons in nanoparticles has been performed by using third-order perturbation theory. The deformation potential approximation is used to describe the electronphonon interaction. The Raman-Brillouin electronic density and the electron-phonon interaction are found to increases with decreasing size of nanoparticle. A good agreement between the calculated and reported low-frequency Raman spectra is found.Comment: 13 pages, 3 figures. Journal of Nanoscience and Nanotechnology (In Press