Focusing by Plano-Concave lens using Negative Refraction

We demonstrate focusing of a plane microwave by a plano-concave lens fabricated from a photonic crystal (PhC) having negative refractive index and left-handed electromagnetic properties. An inverse experiment, in which a plane wave is produced from a source placed at the focal point of the lens is also reported. A frequency dependent negative refractive index, is obtained for the lens from the experimental data which matches well with that determined from band structure calculations

Negative Refraction and Left-handed electromagnetism in Microwave Photonic Crystals

We demonstrate negative refraction of microwaves in metallic photonic crystals. The spectral response of the photonic crystal, which manifests both positive and negative refraction, is in complete agreement with band-structure calculations and numerical simulations. The negative refraction observed corresponds to left-handed electromagnetism and arises due to the dispersion characteristics of waves in a periodic medium. This mechanism for negative refraction is different from that in metamaterials.Comment: 13 pages, 4 figure

Onset of dielectric modes at 110K and 60K due to local lattice distortions in non-superconducting YBa_{2}Cu_{3}O_{6.0} crystals

We report the observation of two dielectric transitions at 110K and 60K in the microwave response of non-superconducting YBa_{2}Cu_{3}O_{6.0} crystals. The transitions are characterized by a change in polarizability and presence of loss peaks, associated with overdamped dielectric modes. An explanation is presented in terms of changes in polarizability of the apical O atoms in the Ba-O layer, affected by lattice softening at 110K, due to change in buckling of the Cu-O layer. The onset of another mode at 60K strongly suggests an additional local lattice change at this temperature. Thus microwave dielectric measurements are sensitive indicators of lattice softening which may be relevant to superconductivity.Comment: 5 pages, 3 ps format figure

Non-linear microwave impedance of short and long Josephson Junctions

The non-linear dependence on applied $ac$ field ($b_{\omega}$) or current ($i_{\omega}$) of the microwave (ac) impedance $R_{\omega}+iX_{\omega}$ of both short and long Josephson junctions is calculated under a variety of excitation conditions. The dependence on the junction width is studied, for both field symmetric (current anti-symmetric) and field anti-symmetric (current symmetric) excitation configurations.The resistance shows step-like features every time a fluxon (soliton) enters the junction, with a corresponding phase slip seen in the reactance. For finite widths the interference of fluxons leads to some interesting effects which are described. Many of these calculated results are observed in microwave impedance measurements on intrinsic and fabricated Josephson junctions in the high temperature superconductors, and new effects are suggested. When a $$ field ($b_{dc}$) or current ($i_{dc}$) is applied, interesting phase locking effects are observed in the ac impedance $Z_{\omega}$. In particular an almost periodic dependence on the dc bias is seen similar to that observed in microwave experiments at very low dc field bias. These results are generic to all systems with a $\cos (\phi)$ potential in the overdamped limit and subjected to an ac drive.Comment: 7 pages, 11 figure

Bio-nanotechnology application in wastewater treatment

The nanoparticles have received high interest in the field of medicine and water purification, however, the nanomaterials produced by chemical and physical methods are considered hazardous, expensive, and leave behind harmful substances to the environment. This chapter aimed to focus on green-synthesized nanoparticles and their medical applications. Moreover, the chapter highlighted the applicability of the metallic nanoparticles (MNPs) in the inactivation of microbial cells due to their high surface and small particle size. Modifying nanomaterials produced by green-methods is safe, inexpensive, and easy. Therefore, the control and modification of nanoparticles and their properties were also discussed

A Crystallized Treatise on Determinants of Motivational Environment in Oil and Natural Gas Corporation Limited (ONGC)

Technologies have become stakes and those companies who can turn strategy into action at jet speed can bring seamless changes in the organization. In this context motivation has become an important HR intervention in making human resources effective. Companies realized the importance of the motivation as the contribution of employees directly relates their vision and mission statements. Demotivated workforce can cause havoc in failing to meet the organizational objectives.  It has the role to develop and intensify the desire of every member of the organization to work effectively and efficiently in their roles. After employees are hired and trained, it is important to motivate them to get the desired efforts from them, to achieve organizational objectives. Owing to the stiff competition among the Multi Nationals in retaining them has become challenge, this paper focus on motivating the workforce by introducing various HR Interventions to motivate and retain for the benefit of the organizational objectives.  For this cause a range of motivational factors were considered for a critical assessment on motivational environment in ONGC. Keywords: Motivation, technology, environment, organizational objectives, workforce DOI: 10.7176/EJBM/13-11-03 Publication date:June 30th 202

The complex genetics of gait speed:Genome-wide meta-analysis approach

Emerging evidence suggests that the basis for variation in late-life mobility is attributable, in part, to genetic factors, which may become increasingly important with age. Our objective was to systematically assess the contribution of genetic variation to gait speed in older individuals. We conducted a meta-analysis of gait speed GWASs in 31,478 older adults from 17 cohorts of the CHARGE consortium, and validated our results in 2,588 older adults from 4 independent studies. We followed our initial discoveries with network and eQTL analysis of candidate signals in tissues. The meta-analysis resulted in a list of 536 suggestive genome wide significant SNPs in or near 69 genes. Further interrogation with Pathway Analysis placed gait speed as a polygenic complex trait in five major networks. Subsequent eQTL analysis revealed several SNPs significantly associated with the expression of PRSS16, WDSUB1 and PTPRT, which in addition to the meta-analysis and pathway suggested that genetic effects on gait speed may occur through synaptic function and neuronal development pathways. No genome-wide significant signals for gait speed were identified from this moderately large sample of older adults, suggesting that more refined physical function phenotypes will be needed to identify the genetic basis of gait speed in aging