10 research outputs found
Design and Development of Compact Conformal Microstrip Antenna at S-Band
A compact microstrip antenna at S-Band is described in this work. This paper presents the theoretical and experimental investigations on conformal 90° Sectoral circular microstrip antenna using shorting wall. The performance of antenna characteristics is obtained using FEM based HFSS software and the computed results are verified by measurement. Here, microstrip antenna is loaded with shorting wall to achieve frequency reduction of about 75 per cent. The antenna characteristics were studied with radome surrounded by metallic ring. The radiation characteristics of antenna mounted on vehicle body is carried out. The antenna has moderate gain and wider coverage in roll plane as well as azimuth plane and may be used as small, compact antenna for onboard telemetry applications
Sodium ion storage in reduced graphene oxide
The performance of few-layered metal-reduced graphene oxide (RGO) as a negative electrode material in sodium-ion battery was investigated. Experimental and simulation results indicated that the as-prepared RGO with a large interlayer spacing and disordered structure enabled significant sodium-ion storage, leading to a high discharge capacity. The strong surface driven interactions between sodium ions and oxygen-containing groups and/or defect sites led to a high rate performance and cycling stability. The RGO anode delivered a discharge capacity of 272 mA h g(-1) at a current density of 50mAg(-1), a good cycling stability over 300 cycles and a superior rate capability. The present work provides new insights into optimizing RGOs for high-performance and low-cost sodium-ion batteries. (C) 2016 Elsevier Ltd. All rights reserved
Multiparent-Derived, Marker-Assisted Introgression Lines of the Elite Indian Rice Cultivar, ‘Krishna Hamsa’ Show Resistance against Bacterial Blight and Blast and Tolerance to Drought
Major biotic stresses viz., bacterial blight (BB) and blast and brown plant hopper (BPH) coupled with abiotic stresses like drought stress, significantly affect rice yields. To address this, marker-assisted intercross (IC) breeding involving multiple donors was used to combine three BB resistance genes—xa5, xa13 and Xa21, two blast resistance genes—Pi9 and Pi54, two BPH resistance genes—Bph20 and Bph21, and four drought tolerant quantitative trait loci (QTL)—qDTY1.1, qDTY2.1, qDTY3.1 and qDTY12.1—in the genetic background of the elite Indian rice cultivar ‘Krishna Hamsa’. Three cycles of selective intercrossing followed by selfing coupled with foreground selection and phenotyping for the target traits resulted in the development of 196 introgression lines (ILs) with a myriad of gene/QTL combinations. Based on the phenotypic reaction, the ILs were classified into seven phenotypic classes of resistance/tolerance to the following: (1) BB, blast and drought—5 ILs; (2) BB and blast—10 ILs; (3) BB and drought—9 ILs; (4) blast and drought—42 ILs; (5) BB—3 ILs; (6) blast—84 ILs; and (7) drought—43 ILs; none of the ILs were resistant to BPH. Positive phenotypic response (resistance) was observed to both BB and blast in 2 ILs, BB in 9 ILs and blast in 64 ILs despite the absence of corresponding R genes. Inheritance of resistance to BB and/or blast in such ILs could be due to the unknown genes from other parents used in the breeding scheme. Negative phenotypic response (susceptibility) was observed in 67 ILs possessing BB-R genes, 9 ILs with blast-R genes and 9 ILs harboring QTLs for drought tolerance. Complex genic interactions and recombination events due to the involvement of multiple donors explain susceptibility in some of the marker positive ILs. The present investigation successfully demonstrates the possibility of rapid development of multiple stress-tolerant/resistant ILs in the elite cultivar background involving multiple donors through selective intercrossing and stringent phenotyping. The 196 ILs in seven phenotypic classes with myriad of gene/QTL combinations will serve as a useful genetic resource in combining multiple biotic and abiotic stress resistance in future breeding programs
Spigolatura triumvirale: il procuratore Manio fra Marco Antonio e il giovane Cesare
We illustrate here the interplay
of decoordination and accessible
pore volume in nanosized supercapacitors, using constant voltage Gibbs
ensemble based grand canonical Monte Carlo simulations for three different
microporous carbon electrodes of known atomistic structure and 1-ethyl-3-methylimidazolium
boron tetrafluoride (EMI-BF<sub>4</sub>) as electrolyte. We demonstrate
that the counterion coordination number decreases with pore size,
and this trend is similar for the electrodes considered, despite their
different structures, suggesting that the pore shape is less important
to this relation, at least for the carbons examined here. It is seen
that ions with low coordination and/or completely decoordinated ions
induce maximum charge, while those with higher coordination induce
less, in accordance with recent MD simulation results which demonstrate
that ions in high degree of confinement (DOC) induce more charge than
those in low DOC. Our results indicate that electrodes with different
pore volumes can exhibit similar capacitances by balancing accessibility
and decoordination effects. Thus, similar capacitance may be obtained
for electrodes having low pore volume, but which can adsorb a small
amount of high charge inducers (decoordinated ions) by virtue of having
suitable pore size, and those having high pore volume and adsorbing
many more low charge inducers (more highly coordinated ions)
High Interfacial Barriers at Narrow Carbon Nanotube–Water Interfaces
Water displays anomalous fast diffusion
in narrow carbon nanotubes
(CNTs), a behavior that has been reproduced in both experimental and
simulation studies. However, little is reported on the effect of bulk
water–CNT interfaces, which is critical to exploiting the fast
transport of water across narrow carbon nanotubes in actual applications.
Using molecular dynamics simulations, we investigate here the effect
of such interfaces on the transport of water across arm-chair CNTs
of different diameters. Our results demonstrate that diffusion of
water is significantly retarded in narrow CNTs due to bulk regions
near the pore entrance. The slowdown of dynamics can be attributed
to the presence of large energy barriers at bulk water–CNT
interfaces. The presence of such intense barriers at the bulk–CNT
interface arises due to the entropy contrast between the bulk and
confined regions, with water molecules undergoing high translational
and rotational entropy gain on entering from the bulk to the CNT interior.
The intensity of such energy barriers decreases with increase in CNT
diameter. These results are very important for emerging technological
applications of CNTs and other nanoscale materials, such as in nanofluidics,
water purification, nanofiltration, and desalination, as well as for
biological transport processes
Structure, energetics and diffusion properties of isomers of trimethyl benzene in beta zeolite: Uptake and Monte Carlo simulation study
A Monte Carlo study along with experimental uptake measurements of 1,2,3-trimethyl benzene, 1,2,4-trimethyl benzene and 1,3,5-trimethyl benzene (TMB) in beta zeolite is reported. The TraPPE potential has been employed for hydrocarbon interaction and harmonic potential of Demontis for modeling framework of the zeolite. Structure, energetics and dynamics of TMB in zeolite beta from Monte Carlo runs reveal interesting information about the diameter, properties of these isomers on confinement. Of the three isomers, 135TMB is supposed to have the largest diameter. It is seen TraPPE with Demontis potential predicts a restricted motion of 135TMB in the channels of zeolite beta.Experimentally, 135TMB has the highest transport diffusivity whereas MID results suggest this has the lowest self diffusivity. (C) 2009 Elsevier Inc. Ail rights reserved
Dye-induced photoluminescence quenching of quantum dots: Role of excited state lifetime and confinement of charge carriers
Molecular and Morphological Characterization of Introgression Lines with Resistance to Bacterial Leaf Blight and Blast in Rice
The present study evaluates marker assisted forward breeding (MAFB)-derived disease resistant introgression lines (ILs) which do not have the targeted resistance genes for bacterial blight (xa5 + xa13 + Xa21) and blast (Pi2 + Pi9 + Pi54). The ILs were derived in the background of two elite rice cultivars, Krishna Hamsa [Recurrent Parent 1 (RP1)] and WGL 14 (RP2), involving multi-parent inter-crossing. Molecular characterization with gene specific markers for seven reported resistance genes each for bacterial blight (Xa33, Xa38, xa23, Xa4, xa8, Xa27 and Xa41) and blast (Pi1, Pi20, Pi38, Pib, Pitp, Pizt and Pi40) revealed the presence of xa8 and Xa38, in addition to the targeted xa5, xa13 and Xa21 for bacterial blight resistance and Pi1, Pi38, Pi40, Pi20, Pib and Pipt, in addition to the targeted Pi9 and Pi54, for blast resistance in various combinations. A maximum of nine resistance genes xa5 + Xa21 + Pi54 + xa8 + Pipt + Pi38 + Pi1 + Pi20 + Pib was observed in RP1-IL 19030 followed by eight genes xa5 + xa13 + Xa21 + xa8 + Pi9 + Pipt + Pi1 + Pi20 in two RP2-ILs, 19344 and 19347. ANOVA revealed the presence of significant variability for all the yield traits except “days to 50% flowering” (DFF). Box plots depicted the seasonal differences in the phenotypic expression of the yield traits. There was significant positive association of grain yield with days to flowering, tiller number and panicle number. Thousand grain weight is also significantly and positively correlated with grain yield. On the contrary, grain yield showed a significantly negative association with plant height. Multi-parent selective inter-crossing in the present study not only led to the development of high yielding disease resistant ILs but also enhanced recovery of the recurrent parent via selection for essential morphological features. More than 90.0% genetic similarity in the ILs based on SNP-based background selection demonstrated the success of multi-parent selective intercrossing in the development of disease resistant NILs