An off-lattice, self-learning kinetic Monte Carlo method using local environments

We present a method called local environment kinetic Monte Carlo (LE-KMC) method for efficiently performing off-lattice, self-learning kinetic Monte Carlo (KMC) simulations of activated processes in material systems. Like other off-lattice KMC schemes, new atomic processes can be found on-the-fly in LE-KMC. However, a unique feature of LE-KMC is that as long as the assumption that all processes and rates depend only on the local environment is satisfied, LE-KMC provides a general algorithm for (i) unambiguously describing a process in terms of its local atomic environments, (ii) storing new processes and environments in a catalog for later use with standard KMC, and (iii) updating the system based on the local information once a process has been selected for a KMC move. Search, classification, storage and retrieval steps needed while employing local environments and processes in the LE-KMC method are discussed. The advantages and computational cost of LE-KMC are discussed. We assess the performance of the LE-KMC algorithm by considering test systems involving diffusion in a submonolayer Ag and Ag-Cu alloy films on Ag(001) surface.     

Effect of complementary small molecules on the properties of bicomponent hydrogel of riboflavin

Three new bicomponent hydrogels of riboflavin (R) with salicylic acid (S), dihydroxybenzoic acid (B) and acetoguanamine (D) in 1:1 molar ratio have been reported. FTIR and UV-vis spectra suggest formation of H-bonded complexes in 1:1 molar ratio of the components. The network consists of tape, bar and helical tubes for RB11, RS11 and RD11 systems, respectively. Reversible first order phase transition and invariant storage modulus (G') with angular frequency (ω) characterise the systems as forming thermoreversible hydrogels. The RD11 gel has the highest gel melting temperature and highest critical strain compared to other gels. WAXS study indicates different crystal structures for different gels. NMR spectra reveals higher shielding of protons in RD11 gel suggesting better π-stacking compared to RS11 and RB11 gels. RD11 gel shows two-fold enhancement of photoluminescence (PL) intensity with a substantial red shift of emission peak but RB11 and RS11 gels show PL-quenching. The gels exhibit a small decrease in lifetime and the PL property is very much temperature and pH dependent. So the complementary molecules have a pronounced effect on morphology, structure, stability and optical property of riboflavin gels.     

A uniqueness result related to certain non-linear differential polynomials sharing the same 1-points

We prove some uniqueness theorems concerning the derivatives of meromorphic functions when they share two or three sets which will improve some existing results.     

Fluorescent nanoparticles based on a microporous organic polymer network: fabrication and efficient energy transfer to surface-bound dyes

Well-defined nanoparticles composed of a tetraphenylmethane-based microporous polymer network with an average particle diameter of 30-60 nm were fabricated by a miniemulsion polymerization technique. Strong green emission was observed and efficient excitation energy transfer from nanoparticles to surface-bound dye molecules was explored.     

Synthesis of a boronated amino acid as a potential neutron therapy agent: 1-amino-3-[(dihydroxyboryl)ethyl]cyclobutanecarboxylic acid

A novel boronated aminocyclobutanecarboxylic acid was synthesized in 10 steps for potential use in neutron capture therapy. The molecule was modeled after the unnatural amino acid 1-aminocyclobutanecarboxylic acid, which has shown high uptake in brain tumors.     

Mean-field theories of spin glasses

Different kinds of mean-field theories (MFT) of spin glasses (SG) are reviewed. A brief introductory review of major experimental results, which have to be explained theoretically, is presented in the beginning. Marshall-Klein-Brout type random local field theories are described qualitatively. Edwards-Anderson MFT of SG transition is introduced after defining the various relevant order parameters. Almost all the static and dynamic approaches to the solution of the Sherrington-Kirkpatrick model are reviewed in detail. The existence of mixed phase(s) in the MFT of vector SG is examined critically in the light of recent theories and experiments. The existence of macroscopic anisotropy energy in SG and their microscopic origin are mentioned. The upper and lower critical dimensionalities obtained by different authors are enlisted. The concept of frustration and its deeper connection with other branches of human knowledge are indicated. Nonlinear susceptibilities, spin wave and relaxational modes in SG are also reviewed. The two-level-system picture of SG, its physical basis and important consequences are presented. The Tholence-Tournier-Wohlfarth phenomenological cluster model of SG is discussed with a stress on the role of measurement time. SG transition has been described as percolation and localization-delocalization problems. Some special features of the local field distribution in SG are mentioned. Some results of computer simulation on the various models of SG are summarized. The theories of the transport properties of SG are enlisted. Recent trends in the theory of SG are indicated at the end.     

Probing CPT violation in neutrino oscillation: A three flavor analysis

We have studied CPT violation in neutrino oscillation considering three flavor framework with matter effect. We have constructed a new way to find the oscillation probability incorporating CPT violating terms without any approximation. Then CPT   violation with atmospheric neutrinos for a magnetized iron calorimeter detector considering the muons (directly measurable with high resolution) of the charge current events has been studied for zero and nonzero θ₁₃${\theta }_{13}$ values. It is found that a potential bound of δb₃₂?6×¹⁰⁻²⁴ GeV$\delta b_{32}?6\times {10}^{-24}\text{GeV}$ at 99% CL can be obtained with 1 Mton.year exposure of this detector; and unlike neutrino beam experiments, there is no possibility to generate ‘fake’ CPT violation due to matter effect with atmospheric neutrinos. The advantages of atmospheric neutrinos to discriminate CPT violation from CP violation and nonstandard interactions are also discussed.     

Hadron mass spectrum from lattice QCD

Finite temperature lattice simulations of quantum chromodynamics (QCD) are sensitive to the hadronic mass spectrum for temperatures below the "critical" temperature T(c) ≈ 160 MeV. We show that a recent precision determination of the QCD trace anomaly shows evidence for the existence of a large number of hadron states beyond those known from experiment. The lattice results are well represented by an exponentially growing mass spectrum up to a temperature T=155 MeV. Using simple parametrizations of the hadron mass spectrum we show how one may estimate the total spectral weight in these yet undermined states.