Nucleus-acoustic solitary waves in self-gravitating degenerate quantum plasmas

Nucleus-acoustic(NA) solitary waves(SWs) propagating in a self-gravitating degenerate quantum plasma(SDQP)system(containing non-relativistically degenerate heavy and light nuclei,and non-/ultra-relativistically degenerate electrons) have been theoretically investigated.The modified Korteweg–de Vries(m K-d V) equation has been derived for both planar and non-planar geometry by employing the reductive perturbation technique.It is shown that the NA SWs exist with positive(negative) electrostatic(self-gravitational) potential.It is also observed that the effects of non-/ultra-relativistically degenerate electron pressure,dynamics of non-relativistically light nuclei,spherical geometry,etc.significantly modify the basic features(e.g.,amplitude,width,speed,etc.) of the NA SWs.The applications of our results,which are relevant to astrophysical compact objects,like white dwarfs and neutron stars,are briefly discussed.     

Counters Designs with Minimum Number of Cells and Area in the Quantum-Dot Cellular Automata Technology

The quantum-dot cellular automata (QCA) were highly regarded due to its high operating frequency and significantly low power consumption. One of the most useful circuits in processors architecture is counter. This paper presents effective designs and arrangement of QCA based counter-circuits. In this study new counter circuits in QCA technology are designed and precise simulation are done using the QCADesigner. Three, four and five bits counters are proposed in this paper in QCA technology. A comparison is made between the past and recent designs to illustrate which method is better and more efficient in terms of area, complexity, number of cells, and delay. For example, the proposed three bit shift register has 174 quantum cells, 0.2μm² occupied area and three QCA clock cycles delay.

     

Elastic scattering of e∓ by Na atoms

ABSTRACT

The differential, integrated elastic, momentum transfer, viscosity and total cross-sections along with Sherman function for the elastic scattering of electrons and positrons by sodium atoms have been calculated within the framework of complex projectile–atom optical potential model at the impact energies 0.1 ≤ E_i ≤ 10⁴ eV for both the projectiles. The relativistic Dirac partial wave techniques, with accurate analytical charge densities, are used to obtain the scattering amplitudes. The present results produce satisfactory agreement with the experimental measurements and other theoretical calculations available in the literature.     

Spectrophotometric determination of copper(ii) with acid alizarin black s.n.

Acid alizarin black SN (AABSN) gives a colour reaction with copper(II) in aqueous solution (ε650 = 28,000) which provides greater sensitivity than any other method in the visible range of the spectrum except dithizone. The complex is extremely stable, and EDTA can be used to mask most ions. Only Th, Bi, La(III), Fe(III) and Co(II) interfere seriously. The interference of the first 4 can readily be overcome by coprecipitation with aluminium hydroxide. The nature of the two complexes formed between copper(II) ions and AABSN was examined by procedures of continuous variation.     

Influence of dispersing agents and solution conditions on the solubility of crude kaolin

Experiments measuring the solubility of kaolin particles in terms of the concentration of aluminum and silicon ions in supernatant were carried out as a function of the pH of the slurry over a wide range of dosages of different dispersing agents varying from 0.5 to 12 mg/(g solids). The concentrations of the metal ions in supernatant were found to be strongly affected by the type and the dosage of the dispersants and pH of the solution. In this study, the mechanism of the reaction between the dispersing agents and kaolin particles was studied and the dissolution capacities of metal ions (aluminum and silicon) were identified from kaolin particles in the absence and presence of dispersing agents. The three anionic dispersing agents used were sodium polyacrylate (Na-PAA), sodium hexametaphosphate (Na-HMP), and sodium silicate (Na-silicate), based on the industrial application of these agents and their ability to produce a stable dispersion for this purpose.     

Reactions within association complexes: the reaction of imidazole with substituted phenyl acetates in the presence of detergents in aqueous solution

The bimolecular rate constants for reaction of imidazole with phenyl acetates complexed with sodium dodecyl sulfate (SDS) or cetyltrimethylammonium bromide (CTAB) micelles obey Bronsted equations with beta 1g similar to that of the reaction in aqueous solution. The dissociation constants of ester (Ks) and the hypothetical dissociation constant (KTS) of the transition state of the micelle complexes obey Hansch equations with similar sensitivities (p) to pi (-0.66 and -0.589 for KS and -0.735 and -0.495 for KTS, respectively). The slopes also indicate that the microsolvation environments associated with the transition state and the complexed ester have aqueous character. The relative values of KTS and KS indicate that the transition state of the reaction of imidazole with ester is more weakly complexed to both micelles than is the reactant ester. Log KTS values are linear functions of log KS for reactions with both CTAB and SDS; the slopes are, respectively, -0.893 and -1.19 consistent with a slightly more "water-like" medium for the transition state than for the site of binding of ester with CTAB-micelle and slightly less for the SDS-micelle. The results for ester and transition state are consistent with the location of the phenyl residue in a hydrophobic region that possesses water molecules. It is concluded that the acetyl group in the complexed transition state is located in an aqueous part of the Stern region, whereas the phenyl residue is in a part of the Stern region that possesses alkane components. The derived kinetic and complexation parameters in these experiments refer to micelles with Stern regions that have been maintained at constant ionic compositions.     

New hydrogen-bonded donor-acceptor pairs between dipyridylacetylenes and 2,5-dichloro-3,6-dihydroxyl-1,4-benzoquinone

[structure: see text] The crystalline donor-acceptor hydrogen-bonding complexes between 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone (chloranilic acid) and dipyridylacetylenes (DPA) [2,2'-DPA, 3,3'-DPA, and 4,4'-DPA] were prepared, and crystal structures were revealed by X-ray analysis. The structures of the complexes are formed by intermolecular hydrogen-bonding interactions and demonstrate three supramolecular architectures based on a new common supramolecular synthon, which allows the formation of a different stacking arrangement and ionicity.     

On the Symmetry Structures of the Minkowski Metric and a Weyl Re-Scaled Metric

Symmetries of spacetime manifolds which are given by Killing vectors are compared with the symmetries of a Lagrangian constructed from a Weyl re-scaled metric used in discussing disorder operators in Gauge theories. We find the point generators of the one parameter Lie groups of transformations that leave invariant the action integral corresponding to the Lagrangian (Noether symmetries). It is shown that the Noether symmetries obtained by considering the Lagrangian provide additional symmetries which are not provided by the Killing vectors. New conservation law/s are determined.     

Inhibitory Effect of Nepeta deflersiana on Climax Bacterial Community Isolated from the Oral Plaque of Patients with Periodontal Disease

Background: The red-complex bacteria are one of the most significant complexes found simultaneously in subgingival plaque next to the periodontal pocket. The current antibacterial treatment is not adequate, and multidrug resistance to it is developing. Henceforth, the antibacterial effect of the ethanolic extract of Nepeta deflersiana was put to test against red-complex bacteria in patients with chronic periodontitis. Methods: Well diffusion and micro broth dilution procedure by Alamar blue were applied to assess the zone of inhibition (ZOI), the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC). Anti-virulence efficacies of the plant extract that comprise of adherence and formation of biofilms were examined by the process of adherence and biofilm production assay. Results: The crude extract of Nepeta deflersiana exhibited significant inhibitory outcome against periodontopathic bacteria with noteworthy MIC (0.78–3.12 mg/mL), inhibitory zone (12–20 mm), as well as MBC (3.12–12.50 mg/mL). The N. deflersiana extract inhibited bacterial adhesion ranging from 41% to 52%, 53% to 66%, and 60% to 79% at the given MIC × 0.5, MIC × 1, and MIC × 2 in succession. Substantial suppression was also developed in the biofilm production of the investigated periodontopathic strains following exposure to numerous concentrations of N. deflersianan extract for a period of 24 and 48 h. Conclusion: These outcomes divulge a new concept that N. deflersiana extract can be utilized to manufacture valuable antibacterial compounds to treat chronic and acute periodontitis. This identifies N. deflersiana as an essential natural source for future drug development.     

Regio- and stereoselective functionalization of alkenes with emphasis on mechanistic insight and sustainability concerns

Alkene is an attractive substrate for chemists due to its easy availability and reactivity towards large number of reactants affording diverse range of organic compounds. It reacts under ionic and free radical mechanisms including single electron transfer (SET). In this review, strategies used for C–C and C-heteroatom functionalization of alkene has been discussed with emphasis on the regio, stereoselectivity, mechanistic detail and sustainability aspects. These strategies mainly follow the free radical mechanism, and the highly reactive carbon radicals show uncontrollable regio- and stereoselectivities. Thus these strategies still need to be focused; especially in the asymmetric versions. The regio- and stereoselectivities of functionalization of alkenes have been highlighted and debated. In addition, the hazardous reagents such as Cl₂, Br₂ I₂, CO, peroxides, and benzene have also been discussed with the emphasis on their impact on the environment. Their plausible green alternatives have also been suggested, such as MX as halogen replacement; CO surrogates (formaldehyde etc.); sustainable aromatic solvents as benzene replacement. The non-green strategies relying on pre-formed silyl hydride and their green alternative strategies such as transfer hydrogenations have also been indicated. The applications of the functionalization of alkenes for the total synthesis of bioactive compounds have also been discussed in detail. In addition, future perspectives are also highlighted for further developments in the functionalization of alkenes.