Derivations and spectral triples on quantum domains II: Quantum annulus

Science China Mathematics - Continuing our study of spectral triples on quantum domains, we look at unbounded invariant and covariant derivations in the quantum annulus. In particular, we...     

Efficiency of the Incomplete Enumeration Algorithm for Monte-Carlo Simulation of Linear and Branched Polymers

We study the efficiency of the incomplete enumeration algorithm for linear and branched polymers. There is a qualitative difference in the efficiency in these two cases. The average time to generate an independent sample of configuration of polymer with n monomers varies as n ² for linear polymers for large n, but as exp(cn ^α) for branched (undirected and directed) polymers, where 0<α<1. On the binary tree, our numerical studies for n of order 10⁴ gives α = 0.333±0.005. We argue that α =1/3 exactly in this case. An erratum to this article can be found at .     

Aspects of auditing in clinical laboratories

Quality and patient safety are terms that both providers and recipients of healthcare are very familiar with. Accreditation is another term that is closely linked to quality and patient safety. Audit is a systematic, independent, and documented process for obtaining evidence and evaluating it objectively to determine the extent to which audit criteria are fulfilled. Accreditation and audit are integral components of the same process. Three different types of audit are well recognized—internal, external, and co-operative. Reading of relevant documents, observation of laboratory practices, and asking open-ended probing questions are important auditing techniques. For auditing to be successful, experienced, qualified, and well trained auditors are essential. Furthermore, the auditor should be open-minded, not prejudiced, a team player and effective communicator, both in writing and verbally. In many instances, the emphasis for seeking laboratory accreditation has shifted from building quality systems—to produce reliable results and ensure patient safety—to just passing the inspection. Recently, the emphasis for laboratory quality improvement has been placed on pre and post-analytical processes in preference to analytical quality. The analytical quality of laboratory results is still far from ideal and it may be detrimental if less emphasis is placed on this aspect of laboratory medicine. Auditing or on-site inspection as a regulatory tool does not work or present a realistic picture of laboratory quality. A continuous quality improvement approach will help laboratories to build quality into their systems. Presented at the Conference “Excellence in Laboratory Medicine”, November 2007, Al Ain, United Arab Emirates.     

Influence of γ-irradiation on the non-isothermal decomposition of calcium-gadolinium oxalate

Thermal decomposition of co-precipitated unirradiated and irradiated Ca-Gd oxalate has been studied by adopting differential thermal analysis (DTA) and thermogravimetric (TG) techniques. The reaction occurs through two stages corresponding to the decomposition of gadolinium oxalate (Gd-Ox) followed by that of calcium oxalate (Ca-Ox). The kinetic parameters for both the stages are calculated by using solid state reaction models and Coats-Redfern's equation. The co-precipitation as well as irradiation alter the DTA peak temperatures and the kinetic parameters of Ca-Ox. The decomposition of Gd-Ox follows the two dimensional Contracting area ( R 2 ) mechanism, while that of Ca-Ox follows the Avrami-Erofeev ( A 2 ) mechanism ( n =2), which are also exhibited by the co-precipitated and irradiated samples. Co-precipitation decreases the energy of activation and the pre-exponential factor of the individual components but the reverse phenomenon takes place upon irradiation of the co-precipitate. The mechanisms underlying the phenomena are explored.     

Effect of γ-irradiation and semiconducting oxide (tio2) on the thermal decomposition of mgc2o4: A comparative study

The simultaneous rising temperature (DTA-TG) technique and the gas evolution method are adopted for studying the thermal decomposition of unirradiated and irradiated MgC₂O₄ and MgC₂O₄ + TiO₂ mixtures. The data are applied to theories of different solid state reaction models and the best fit is obtained for the Avrami-Erofeev mechanism (n=2) suggesting that both the nucleation and growth processes occur at the reactant product interface in a two dimensional chain branching manner. Low irradiation doses decrease the rate of reaction remarkably whereas the reverse phenomenon takes place at higher doses. The n-type semiconducting oxide, TiO₂ (5-40 mol%) enhances the rate of decomposition which increases with increasing concentration of the catalyst. The influence of n -irradiation is explained in the light of defects, dislocations and electron-hole (e^?, h⁺) pairs generated in the lattice, whereas the influence of TiO₂ is understood on the basis of electron transfer process involved in the reaction.     

Transition curves for the variance of the nearest neighbor spacing distribution for Poisson to Gaussian orthogonal and unitary ensemble transitions

Using an appropriate 2x2 random matrix ensemble, transition curves for the variance of the nearest neighbor spacing distribution are constructed for the Poisson to Gaussian orthogonal and unitary ensemble transitions in terms of an easily identifiable transition parameter.     

Quenched Averages for Self-Avoiding Walks and Polygons on Deterministic Fractals

We study rooted self avoiding polygons and self avoiding walks on deterministic fractal lattices of finite ramification index. Different sites on such lattices are not equivalent, and the number of rooted open walks W _n (S), and rooted self-avoiding polygons P _n (S) of n steps depend on the root S. We use exact recursion equations on the fractal to determine the generating functions for P _n (S), and W _n(S) for an arbitrary point S on the lattice. These are used to compute the averages ,, and over different positions of S. We find that the connectivity constant μ, and the radius of gyration exponent are the same for the annealed and quenched averages. However, , and , where the exponents and , take values different from the annealed case. These are expressed as the Lyapunov exponents of random product of finite-dimensional matrices. For the 3-simplex lattice, our numerical estimation gives and , to be compared with the known annealed values and .     

Facile combustion synthesis of Ag2O nanoparticles using cantaloupe seeds and their multidisciplinary applications

Silver oxide nanoparticles (Ag₂O NPs) were prepared using cantaloupe (Cucumis melo) seeds as a fuel by employing a green synthesis method. The prepared Ag₂O NPs were investigated using powder X-ray diffraction (PXRD), UV–visible spectrum, Fourier transform infrared analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy-dispersive spectroscopy, and photoluminescence studies. PXRD data reveal the establishment of cubic crystal structure of Ag₂O NPs. According to SEM and TEM results, the morphology of the prepared NPs was agglomerated and spherical. The photodegradation activity of the prepared Ag₂O NPs over methylene blue dye was promising under visible light irradiation. Furthermore, the antimicrobial assay of the synthesized Ag₂O NPs was carried out by the disc diffusion method against Gram-positive and Gram-negative microbial strains.     

Thermo-hydraulic and entropy generation analysis of recharging microchannel using water-based graphene–silver hybrid nanofluid

Journal of Thermal Analysis and Calorimetry - This work numerically investigates thermo-hydraulic and entropy generation characteristics of water-based graphene–silver (Gr–Ag) hybrid...     

Enhanced dielectric and electrical performance of phosphonic acid-modified tantalum (Ta)-doped potassium sodium niobate (KNaNbO3)-P(VDF-HFP) composites

The European Physical Journal E - We discuss the lateral dynamics of two active force dipoles, which interact with each other via hydrodynamic interactions in a thin fluid layer that is active and...