Error analysis for rotating active Stokes-Mueller imaging polarimeters

Retrieval of Mueller matrices from intensity measurements is a noise-sensitive process. In addition, the choice of the method used for extracting Mueller matrix elements greatly influences the precision of the final results. Among available procedures, three have been tested and their robustness analyzed by adding Gaussian noise to computer synthesized data and have been verified by comparing experimental data. As expected, the methods based on classical matrix inversion reach their noise reduction limit even if more data are considered. In contrast, the discrete Fourier transform approach features a remarkable stability. The identified reason is that the retrieval process corresponds to filtering with a periodic kernel.     

Effects of thermal fluctuations on non-minimal regular magnetic black hole

We analyze the effects of thermal fluctuations on a regular black hole (RBH) of the non-minimal Einstein–Yang–Mill theory with gauge field of magnetic Wu–Yang type and a cosmological constant. We consider the logarithmic corrected entropy in order to analyze the thermal fluctuations corresponding to non-minimal RBH thermodynamics. In this scenario, we develop various important thermodynamical quantities, such as entropy, pressure, specific heats, Gibb’s free energy and Helmholtz free energy. We investigate the first law of thermodynamics in the presence of logarithmic corrected entropy and non-minimal RBH. We also discuss the stability of this RBH using various frameworks such as the \(\gamma \) factor (the ratio of heat capacities), phase transition, grand canonical ensemble and canonical ensemble. It is observed that the non-minimal RBH becomes globally and locally more stable if we increase the value of the cosmological constant.     

Impact of generalized dissipative coefficient on warm inflationary dynamics in the light of latest Planck data

The warm inflation scenario in view of the modified Chaplygin gas is studied. We consider the inflationary expansion to be driven by a standard scalar field whose decay ratio \(\Gamma \) has a generic power-law dependence with the scalar field \(\phi \) and the temperature of the thermal bath T. By assuming an exponential power-law dependence in the cosmic time for the scale factor a(t), corresponding to the intermediate inflation model, we solve the background and perturbative dynamics considering our model to evolve according to (1) weak dissipative regime and (2) strong dissipative regime. Specifically, we find explicit expressions for the dissipative coefficient, scalar potential, and the relevant inflationary observables like the scalar power spectrum, scalar spectral index, and tensor-to-scalar ratio. The free parameters characterizing our model are constrained by considering the essential condition for warm inflation, the conditions for the model evolves according to weak or strong dissipative regime, and the 2015 Planck results through the \(n_s\)–r plane.     

Two Novel Lyso-Ornithine Lipids Isolated from an Arctic Marine Lacinutrix sp. Bacterium

The Lacinutrix genus was discovered in 2005 and includes 12 Gram-negative bacterial species. To the best of our knowledge, the secondary metabolite production potential of this genus has not been explored before, and examination of Lacinutrix species may reveal novel chemistry. As part of a screening project of Arctic marine bacteria, the Lacinutrix sp. strain M09B143 was cultivated, extracted, fractionated and tested for antibacterial and cytotoxic activities. One fraction had antibacterial activity and was subjected to mass spectrometry analysis, which revealed two compounds with elemental composition that did not match any known compounds in databases. This resulted in the identification and isolation of two novel isobranched lyso-ornithine lipids, whose structures were elucidated by mass spectrometry and NMR spectroscopy. Lyso-ornithine lipids consist of a 3-hydroxy fatty acid linked to the alpha amino group of an ornithine amino acid through an amide bond. The fatty acid chains were determined to be iso-C15:0 (1) and iso-C16:0 (2). Compound 1 was active against the Gram-positive S. agalactiae, while 2 showed cytotoxic activity against A2058 human melanoma cells.     

Anisotropic Inflationary Scenario Via Generalized Chaplygin Gas Model

We investigate generalized chaplygin gas for warm inflationary scenario in the context of locally rotationally symmetric Bianchi type I universe model.We assume two different cases of dissipative coefficient,i.e.,constant as well as function of scalar field.We construct dynamical equations as well as a relationship between scalar and radiation energy densities under slow-roll approximation.We also derive slow-roll parameters,scalar and tensor power spectra,scalar spectral index,tensor to scalar ratio for analyzing inflationary background during high dissipative regime.We also use the WMAP7 data for the discussion of our parameters.     

Overlap of Doxycycline Fluorescence with that of the Redox-Sensitive Intracellular Reporter roGFP

Tetracycline-inducible systems allow for either suppression or induction of transgene expression to facilitate studies of cell physiology. Doxycycline is a preferred inducer for these gene expression systems due to its membrane permeability; however, the heterocyclic structure of doxycycline exhibits fluorogenic properties that can potentially bias measurement of other fluorochromes. Thus the simultaneous use of tetracycline-inducible systems and fluorescent proteins as reporter genes or as intracellular biosensors may lead to potentially confounding results. Herein, using cells which co-express the ratiometric redox sensitive intracellular reporter, roGFP, and a tetracycline-inducible reporter plasmid encoding the reporter gene, mCherry, as a model system, we describe the overlapping intracellular fluorescent signals between doxycycline and commonly used intracellular fluorescent probes. In our cells, the addition of doxycycline to cells caused a dose- and time-dependent increase in cell fluorescence with 405 nm excitation which overlapped with that of the oxidized configuration of roGFP. Incubating cells in concentrations of doxycycline less than 1 μg/mL and removing doxycycline from the media 60 min before performing experiments eliminated fluorescence interference while still maintaining maximal reporter transgene activation.     

Impedance study of polymethyl methacrylate composites/multi-walled carbon nanotubes (PMMA/MWCNTs)

The dielectric behavior of polymethyl methacrylate/multi-walled carbon nanocomposites (PMMA/MWCNTs) was investigated using impedance spectroscopy technique. The composites were prepared using melt mixing with MWCNTs loading ranging from 0.01 to 10 wt%. The experimental results showed that the measured impedance reflects the insulating behavior of the host material (PMMA) with no appreciable effects of the filler less than 8.5 wt%. However, for the sample containing 10 wt%, the calculated value of dc conductivity increases with increasing temperature from 2.0×10⁻⁶ (Ω m)⁻¹ to attain a value of 4.8×10⁻⁶ (Ω m)⁻¹ at 110 °C. The percolation threshold derived from the dielectric data was estimated to be higher than 8.5 wt% and lower than 10 wt%. A temperature dependent electrical relaxation phenomenon was only observed in the sample containing 10 wt% of MWCNTs. The frequency dependence of the ac conductivity data followed a power law.     

Studies of the Rate Constant of l-DOPA Oxidation and Decarboxylation by HPLC

The objective of current investigation was to study the degradation behavior of l-DOPA under different conditions by high performance liquid chromatography (HPLC), and to develop and validate a stability-indicating HPLC method. The developed RP-HPLC method was validated with respect to linearity, accuracy, precision and specificity. Oxidation was found to occur in alkaline and to some extent in thermal conditions, while the drug was stable when incubated at acidic conditions and under photolytic stress. The oxidation of l-DOPA was observed to follow first-order kinetics. The degradation rate constants and half-life were calculated. The cytotoxicity and enzymatic degradation of l-DOPA was examined using the human intestinal epithelial Caco-2 cells. The drug was rapidly decarboxylated by aromatic amino acid decarboxylase to dopamine. The conversion of l-DOPA to dopamine was dose- and time-dependent.     

Synthesis of a novel highly efficient flame-retardant coating for cotton fabrics with low combustion toxicity and antibacterial properties

Cellulose - The synthesis of multi-function flame retardants is widely increasing to fulfill industrial and economic goals. In this work, a novel flame retardant, melamine salt of tannic phosphate...     

Effect of annealing on the electrical properties and refractive index of HgI2 single crystals

The effect of annealing on the electrical properties and the refractive index of red mercuric iodide (HgI₂) single crystals is investigated. The ac-impedance and phase angle were measured in the frequency range from 100 Hz to 10 kHz at different annealing temperatures. The ac-conductivity, dielectric constants, loss tangent and the refractive index as a function of frequency are determined. The results are discussed in terms of structural changes taking place as a result of the heat treatment of the HgI₂ single crystals.