Formation of rectifier with gold nanoclusters

Gold nanoclusters encapsulated with organic molecules are of great interest for its possible applications in the fields of molecular electronics, catalysis and medical science. Here we demonstrate that monolayer and bilayer films of thiol-capped gold nanoclusters can exhibit diode-like properties provided controlled spatial asymmetry exist between two tunnel junctions used to connect a thiol capped gold nanoclusters. Current-voltage characteristics of this rectifier were obtained from conducting probe atomic force microscopy measurements and also from conventional two probe resistance measurements. Systematic x-ray reflectivity and atomic force microscopy measurements were carried out to characterize the spatial asymmetry introduced by a monolayer of fatty acid salt gadolinium stearate used to deposit thiol-capped gold nanocluster molecules on hydrophilic SiO2-Si(001) substrate by Langmuir Blodgett technique. This information was used to explain prominent rectification observed in these nano-structured films.Comment: 13 pages, 3 figure

Sharp Raman Anomalies and Broken Adiabaticity at a Pressure Induced Transition from Band to Topological Insulator in Sb2Se3

The nontrivial electronic topology of a topological insulator is thus far known to display signatures in a robust metallic state at the surface. Here, we establish vibrational anomalies in Raman spectra of the bulk that signify changes in electronic topology: an E2 g phonon softens unusually and its linewidth exhibits an asymmetric peak at the pressure induced electronic topological transition (ETT) in Sb2Se3 crystal. Our first-principles calculations confirm the electronic transition from band to topological insulating state with reversal of parity of electronic bands passing through a metallic state at the ETT, but do not capture the phonon anomalies which involve breakdown of adiabatic approximation due to strongly coupled dynamics of phonons and electrons. Treating this within a four-band model of topological insulators, we elucidate how nonadiabatic renormalization of phonons constitutes readily measurable bulk signatures of an ETT, which will facilitate efforts to develop topological insulators by modifying a band insulator

Raman anomalies as signatures of pressure induced electronic topological and structural transitions in black phosphorus: Experiments and Theory

We report high pressure Raman experiments of Black phosphorus up to 24 GPa. The line widths of first order Raman modes A$^1_g$, B$_{2g}$ and A$^2_g$ of the orthorhombic phase show a minimum at 1.1 GPa. Our first-principles density functional analysis reveals that this is associated with the anomalies in electron-phonon coupling at the semiconductor to topological insulator transition through inversion of valence and conduction bands marking a change from trivial to nontrivial electronic topology. The frequencies of B$_{2g}$ and A$^2_g$ modes become anomalous in the rhombohedral phase at 7.4 GPa, and new modes appearing in the rhombohedral phase show anomalous softening with pressure. This is shown to originate from unusual structural evolution of black phosphorous with pressure, based on first-principles theoretical analysis.Comment: 13pages, 12figure

Growth and production potential of pigeonpea (Cajanus cajan L.) as influenced by intercropping and integrated nutrient management

A field experiment was conducted during the rainy season of 2010-11 at Varanasi to evaluate the production potential of pigeonpea (Cajanus cajan L. Mill sp.) in intercropping with different fertility levels. The pigeonpea+urdbean intercropping system exhibited its superiority by recording higher growth attribute i.e. plant height (231.22 cm plant-1), no. of branches (18.20 plant-1), dry matter accumulation (213.25 g plant-1), LAI (3.45), yield attribute i.e. no. of pods (135.57 plant-1), no. of grain (4.06 pod-1), Test weight (106.07g), and yield i.e. grain yield (1792.29 kg ha-1) and stalk yield (7614.97 kg ha-1). Application of 100% recommended dose of fertilizer (RDF)+2.5t VC fertility level recorded its superiority by recording higher growth attribute i.e. plant height (232.42 cm plant-1), no. of branch (19.07 plant-1), dry matter accumulation (214.65 g plant-1), LAI (3.62) and yield attributes i.e. no. of pods (141.42 plant-1), no. of grain (4.13 pod-1) and test weight (108.22 g) and yield i.e. grain yield (1831.82 kg ha-1), and stalk yield (8221.61 kg ha-1) over all fertility levels. In the cultivation of long duration crops, the short duration crop may be used as intercrop to generate additional income for farmers’ and INM practices also reduce cost of fertilizer as well as environmental pollution

Nothing but Relativity, Redux

Here we show how spacetime transformations consistent with the principle of relativity can be derived without an explicit assumption of the constancy of the speed of light, without gedanken experiments involving light rays, and without an assumption of differentiability, or even continuity, for the spacetime mapping. Hence, these historic results could have been derived centuries ago, even before the advent of calculus. This raises an interesting question: Could Galileo have derived Einsteinian relativity

CASE STUDY ON BETA BLOCKERS INDUCED PSORIASIS

Drug-induced Psoriasis is one among the common etiological factors of Psoriasis reported worldwide. Familiar drugs known to cause psoriasiform eruptions include Anti-malarials, Beta blockers, NSAIDs, Lithium. etc. Certain antihypertensives like ACE inhibitors, diuretics are also documented to have caused psoriatic episodes. A 57 y old South-Indian male patient with a history of Hypertension, Diabetes Mellitus, Atrial Fibrillation for 4 y; was on antihypertensive therapy for Hypertension and Atrial Fibrillation with proponolol for past 2 y and metoprolol initially. He was presented to the hospital two weeks after switching on to Metoprolol therapy for chief complaints of erythematous scaly lesions especially over both the extremities and paronydrial appearance of nails. Initially, he was on Propranolol therapy which was then shifted to Metoprolol due to an appearance of oral lesions in the mouth. Metoprolol was now discontinued and switched on to Atenolol. After 1-2 w of therapy with Atenolol, the lesions were found to disappear and no recurrence of psoriatic conditions were found. Proper reviewing of medical history for any allergic reactions and the optimization of drug therapy through Therapeutic Drug Monitoring could be initiated by Clinical Pharmacist in order to avoid such drug-induced flares

Charge density analysis of two proton transfer complexes: understanding hydrogen bonding and determination of in-crystal dipole moments

An experimental charge density study has been carried out on proton-transfer complexes exhibiting nonlinear optical (NLO) properties-melaminium tartrate monohydrate and L-asparaginium picrate employing high-resolution X-ray diffraction at 100 K. Both the complexes crystallize in non-centric space group P21 and the structures exhibit interesting patterns of N-H...O and O-H...O hydrogen bonding. Experimental determination of the dipole moment (μ) for the asymmetric unit reveals that for both the crystals, there is a large cooperative enhancement in the crystalline μ arising essentially due to hydrogen bond mediated charge transfer between the melaminium ion and the L-tartrate in one case, between the Lasparaginium ion and the picrate in the other complex. We have additionally performed theoretical calculations at the density functional theory (DFT) level to understand the origin of enhancement of the dipole moments in the two systems

SU(16) grandunification: breaking scales, proton decay and neutrino magnetic moment

We give a detailed renormalization group analysis for the SU(16) grandunified group with general breaking chains in which quarks and leptons transform separately at intermediate energies. Our analysis includes the effects of Higgs bosons. We show that the grandunification scale could be as low as $\sim 10^{8.5}$ GeV and give examples where new physics could exist at relatively low energy ($\sim 250$ GeV). We consider proton decay in this model and show that it is consistent with a low grandunification scale. We also discuss the possible generation of a neutrino magnetic moment in the range of $10^{-11}$ to $10^{-10}\mu_B$ with a very small mass by the breaking of the embedded SU(2)$_\nu$ symmetry at a low energy.Comment: (16 pages in REVTEX + 6 figures not included) OITS-49

Quantum Discord in a spin-1/2 transverse XY Chain Following a Quench

We report a study on the zero-temperature quantum discord as a measure of two-spin correlation of a transverse XY spin chain following a quench across a quantum critical point and investigate the behavior of mutual information, classical correlations and hence of discord in the final state as a function of the rate of quenching. We show that though discord vanishes in the limit of very slow as well as very fast quenching, it exhibits a peak for an intermediate value of the quenching rate. We show that though discord and also the mutual information exhibit a similar behavior with respect to the quenching rate to that of concurrence or negativity following an identical quenching, there are quantitative differences. Our studies indicate that like concurrence, discord also exhibits a power law scaling with the rate of quenching in the limit of slow quenching though it may not be expressible in a closed power law form. We also explore the behavior of discord on quenching linearly across a quantum multicritical point (MCP) and observe a scaling similar to that of the defect density.Comment: 6 pages, 5 figure