The Nonexistence of Instrumental Variables

The method of instrumental variables (IV) and the generalized method of moments (GMM) has become a central technique in health economics as a method to help to disentangle the complex question of causality. However the application of these techniques require data on a sufficient number of instrumental variables which are both independent and relevant. We argue that in general such instruments cannot exist. This is a reason for the widespread finding of weak instruments.

Effect of Hedging-Integrated Rule Curves on the Performance of the Pong Reservoir (India) During Scenario-Neutral Climate Change Perturbations

This study has evaluated the effects of improved, hedging-integrated reservoir rule curves on the current and climate-change-perturbed future performances of the Pong reservoir, India. The Pong reservoir was formed by impounding the snow- and glacial-dominated Beas River in Himachal Pradesh. Simulated historic and climate-change runoff series by the HYSIM rainfall-runoff model formed the basis of the analysis. The climate perturbations used delta changes in temperature (from 0° to +2 °C) and rainfall (from −10 to +10 % of annual rainfall). Reservoir simulations were then carried out, forced with the simulated runoff scenarios, guided by rule curves derived by a coupled sequent peak algorithm and genetic algorithms optimiser. Reservoir performance was summarised in terms of reliability, resilience, vulnerability and sustainability. The results show that the historic vulnerability reduced from 61 % (no hedging) to 20 % (with hedging), i.e., better than the 25 % vulnerability often assumed tolerable for most water consumers. Climate change perturbations in the rainfall produced the expected outcomes for the runoff, with higher rainfall resulting in more runoff inflow and vice-versa. Reduced runoff caused the vulnerability to worsen to 66 % without hedging; this was improved to 26 % with hedging. The fact that improved operational practices involving hedging can effectively eliminate the impacts of water shortage caused by climate change is a significant outcome of this study

Transformations of q-boson and q-fermion algebras

We investigate the algebras satisfied by q-deformed boson and fermion oscillators, in particular the transformations of the algebra from one form to another. Based on a specific algebra proposed in recent literature, we show that the algebra of deformed fermions can be transformed to that of undeformed standard fermions. Furthermore we also show that the algebra of q-deformed fermions can be transformed to that of undeformed standard bosons.Comment: 7 pages, RevTe

Kinetics & Mechanism of Ag+-catalysed Oxidation of Dicarboxylic Acids by Potassium Peroxydisulphate

1115-111

No Eigenvalue in Finite Quantum Electrodynamics

We re-examine Quantum Electrodynamics (QED) with massless electron as a finite quantum field theory as advocated by Gell-Mann-Low, Baker-Johnson, Adler, Jackiw and others. We analyze the Dyson-Schwinger equation satisfied by the massless electron in finite QED and conclude that the theory admits no nontrivial eigenvalue for the fine structure constant.Comment: 13 pages, Late

Generalized symmetric nonextensive thermostatistics and q-modified structures

We formulate a convenient generalization of the q-expectation value, based on the analogy of the symmetric quantum groups and q-calculus, and show that the q->q^{-1} symmetric nonextensive entropy preserves all of the mathematical structure of thermodynamics just as in the case of non-symmetric Tsallis statistics. Basic properties and analogies with quantum groups are discussed.Comment: 9 pages, 1 figure. To appear in Mod. Phys. Lett.

Development and Validation of Glimepiride and Metformin in Human Plasma by HPLC: An application study

A simple and cost effective RP-HPLC method is developed for simultaneous estimation of glimepiride (GLIM) and metformin (MET) at tablet dosage form using C-18 column (4.6 x 250mm, 5?, 100 A?) with a mobile phase composed ofmethanol: water (90:10% v/v) buffered with ortho phosphoric acid at a flow rate of1.0 mL/min (UV detection at 231 nm). The retention time of both drugs (GLIM and MET) are observed as 4.286 and 2.262 respectively. Human plasma spiking studies of both the API and the formulation at the concentration of (0.2g/mL - 1g/mL) for glimepiride and metformin (1g/mL - 5g/mL) expresses the standard correlation coefficients of 0.9998 and 0.9999 respectively for API and 0.9917 and 0.99 respectively for the tablet dosage form. The mean (%) recoveries of glimepiride and metformin are 99.98 and 99.9% respectively. The % RSD below 0.5 shows the high precision of the proposed method. Assay studies revealed that 98.05% of purity is observed for glimepiride and 99.69 for metformin in a tablet dosage form. Human plasma spiking studies revealed that a minimal quantum of glimepiride had been bound with the plasma proteins compare to metformin in the tablet dosage form. The method was validated as per the ICH guidelines

GREEN SYNTHESIS OF NANOSTRUCTURED ZINC PARTICLES USING AQUEOUS LEAF EXTRACT OF SCHREBERA SWIETENIOIDES ROXB. AND THEIR CATALYTIC APPLICATION IN DEGRADATION OF METHYL ORANGE, CRYSTAL VIOLET DYES AND CHROMIUM METAL

Objective: The present work was aimed to synthesized the zinc nanoparticles (ZnO NPs) using aqueous leaf extract of Schrebera swietenioides Roxb., and further, the green-synthesized ZnO NPs were studied for its efficacy in the degradation of hazardous dyes like methyl orange, crystal violet and hazardous metal such as chromium. Methods: The ZnO NPs were synthesized using aqueous leaf extract of S. swietenioides Roxb., as a green reducing agent and 0.1 M Zinc acetate as metal source and the NPs synthesis was completed within a short period of 6 h. The ZnO NPs synthesized were characterized using SEM, TEM, EDS, XRD, FT-IR and UV-visible spectrophotometer. Further, the synthesized NPs were applied for reduction of pollutant days such as methyl orange, crystal violet and pollutant metal chromium. Results: The synthesis of NPs was monitored by observing the color change in the reaction mixture and UV visible spectral analysis. The UV spectral analysis shows a characteristic absorption wavelength at 379 nm. The synthesized NPs were hexagonal wurtzite form crystals having a spherical shape with rough surfaces with an average size of 68 nm and having 73.7 % of zinc content. At a NPs dose of 1.0 g/l the photocatalytic reduction was observed as 85.33±0.02 %, 86.82±0.095 % and 86.73±0.104 % for crystal violet dye, methyl orange dye and chromium metal, respectively. The NPs shows a high % photocatalytic reduction of chromium metal, crystal violet dye and methyl orange dye with less contact time confirms that the synthesized ZnO NPs were effectively catalyzed the degradation of methyl orange, crystal violet dyes and chromium metal. The NPs were observed to be recyclable and can shows high reduction activity after the completion of three cycles of degradation. Conclusion: Hence it can be concluded that synthesized greener nanocatalyst was efficient for pollutant treatment and demonstrated the power of green biosynthesis for metallic nanoparticles