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

Review: Colchicine, Current Advances and Future Prospects

Ade R, Rai MK. 2010. Colchicine, current advances and future prospects. Nusantara Bioscience 2: 90-96. Colchicine isa toxic natural compound and secondary metabolite commonly produced by plants like Colchicum autumnale and Gloriosa superba. Itis originally used to treat rheumatic complaints, especially gout, and still finds its uses for these purposes today despite dosing issuesconcerning its toxicity. It is also prescribed for its cathartic and emetic effects. Initially oral colchicine has not been approved as a drugby U.S. Food and Drug Administration (FDA). But now FDA approved colchicine as a drug for some disorders. Colchicine's presentmedicinal use is in the treatment of gout and familial mediterranean fever. It is also being investigated for its use as an anticancer drug.In neurons, axoplasmic transport is disrupted by colchicine. Due to all the pharmacological application of colchicine, there is urgentneed to enhance the properties and increase the production of colchicine with the help of in vitro technologies. The present review ismainly focused on the chemistry of colchicine, its medicinal uses and toxicity

Fast analysis of decabrominated diphenyl ether using low-pressure gas chromatography electron-capture negative ionization mass spectrometry

Peer reviewe

Design of HPCF with nearly zero flattened Chromatic Dispersion

Here we have consider an air-silica honeycomb lattice and demonstrate a new approach to the formation of a core defect. The honeycomb lattice has recently been suggested for the formation of a photonic band-gap guiding silica-core. Here we discuss how a core defect can be formed by manipulating the cladding region rather than the core region itself. There are so many difficulties occur during the design process. Because when parameters are being changed the designing varies accordingly. For this purpose we have use HPCF in scalar effective index method (SEIM) and consider chromatic dispersion of HPCF for having air hole diameter 1.0 micro.m, and pitch 2.0 micro.m. The maximum pitch can be consider as 5.0 micro.m and air hole diameter is 9.0 micro.m. Transparent boundary condition (TBC) is proposed here for the calculation of Refractive index of HPCF

Determination of the chromospheric quiet network element area index and its variation during 2008-2011

Generally it has been considered that the plages and sunspots are the main contributors to the solar irradiance. There are small scale structures on the sun with intermediate magnetic fields that could also contribute to the solar irradiance. It has not yet been quantified how much of these small scale structures contribute to the solar irradiance and how much it varies over the solar cycle. In this paper, we used Ca II K images obtained from the telescope installed at Kodaikanal observatory. We report a method to separate the network elements from the background structure and plage regions. We compute the changes in the network element area index during the minimum phase of solar cycle and part of the ascending phase of cycle 24. The measured area occupied by the network elements is about 30% and plages less than 1% of the solar disk during the observation period from February 2008-2011. During the extended period of minimum activity it is observed that the network element area index decreases by about 7% compared to the area occupied by the network elements in 2008. A long term study of network element area index is required to understand the variations over the solar cycle.Comment: 12 pages, 9 Figures, Accepted for publication in RA

Effect of Spacing and Pruning on Growth, Yield and Quality of Cv. Deanna Fig (Ficus carica L.)

The effects of tree spacing (5x2m, 5x2.5m, 5x3m, 5x3.5m and 5x4m) and pruning (8 buds/cane, 6 buds/cane and 4 buds/cane) on vegetative growth, physiological parameters, fruit yield and quality were studied in fig (Ficus carica L.) cv. Deanna in the 3rd and 4th year of its growth during the period 2010-12. It was observed that with increase in tree spacing, growth parameters like leaf number, shoot length, internode length, tree-spread, tree height and tree circumference, along with fruit yield both in terms of fruit number and fruit weight per tree, declined gradually under different pruning levels. Increase in pruning level from 8 buds/cane to 4 buds/cane resulted in increased leaf number, shoot length and internode length. Yield characters, viz., fruit number/tree, fruit weight/tree, fruit number/hectare and fruit weight/hectare were marginally influenced by pruning. However, interaction effects of pruning and spacing were found to be non-significant. Consistently declining trends in photosynthesis rate and stomatal conductance, along with increase in leaf water potential value were observed with increase in spacing. Effects of spacing were more conspicuous than those of pruning. Best results for maintenance of vigour and fruit yield were observed under a spacing of 5x2m or 5x2.5m, and 4 buds/cane pruning. Although there was reduction in average fruit size under closer spacing when compared to wide spacing, fruit quality attributes like TSS and acidity were not affected by various treatments. Effects of closer spacing on growth and yield parameters were more pronounced in the 3rd year as compared to the 4th year, showing better response to treatments in young trees. Fruit yield calculated on per hectare basis showed highest fruit number of 116500-133750 and 274500-299500, and fruit weight of 54.5-62.0 and 158.77- 173.30 quintals/ha, respectively, during the 3rdand 4th year of planting under closer spacing of 5x2m and 4 buds/cane pruning

Properties of Umbral Dots from Stray Light Corrected Hinode Filtergrams

High resolution blue continuum filtergrams from Hinode are employed to study the umbral fine structure of a regular unipolar sunspot. The removal of scattered light from the images increases the rms contrast by a factor of 1.45 on average. Improvement in image contrast renders identification of short filamentary structures resembling penumbrae that are well separated from the umbra-penumbra boundary and comprise bright filaments/grains flanking dark filaments. Such fine structures were recently detected from ground based telescopes and have now been observed with Hinode. A multi-level tracking algorithm was used to identify umbral dots in both the uncorrected and corrected images and to track them in time. The distribution of the values describing the photometric and geometric properties of umbral dots are more easily affected by the presence of stray light while it is less severe in the case of kinematic properties. Statistically, umbral dots exhibit a peak intensity, effective diameter, lifetime, horizontal speed and a trajectory length of 0.29 I_QS, 272 km, 8.4 min, 0.45 km/s and 221 km respectively. The 2 hr 20 min time sequence depicts several locations where umbral dots tend to appear and disappear repeatedly with various time intervals. The correction for scattered light in the Hinode filtergrams facilitates photometry of umbral fine structure which can be related to results obtained from larger telescopes and numerical simulations.Comment: Accepted for publication in ApJ : 10 pages, 10 figures, 3 table