Many people in the materials science and solid-state community are familiar with the acronym "DFT+U." For those less familiar, this technique uses ideas from model Hamiltonians that permit the description of both metals and insulators to address problems of electron over-delocalization in practical implementations of density functional theory (DFT). Exchange-correlation functionals in DFT are o...

In image authentication research, a common approach is to divide a given image into a number of smaller blocks, and embed a fragile watermark into each block. The modifications can therefore be detected in the blocks that have been tampered with. The literature includes many authentication techniques for detecting modifications only. In this paper, we propose a method for recovering the damaged...

The use of formalin-fixed paraffin-embedded (FFPE) tissues for HPV DNA detection by PCR from biopsy materials is not entirely clear in retrospective studies. The aim of our study was to evaluate the usefulness and efficiency of FFPE tissues from laryngeal cancer (LSCC) in HPV detection by immunohistochemistry reaction (IHC) and PCR-DNA enzyme immunoassay method (PCR/DEIA) and to compare with HP...

The term FFT is used to signify a specific method to compute the DFT in an efficient manner. While a transform in its own right, the DFT/FFT can be interpreted in terms of the CT-Fourier transform for a sampled signal x(t). Let us consider a signal x(t), sampled at the time instants nT, n = 0,1,...N-1, and suppose that the signal is 0 outside the sampled interval [0, (N-1)T]. The Fourier transf...

We compare the NMR indirect nuclear spin-spin coupling constants in strychnine calculated using density functional theory (DFT) with the semiempirical relativistic force field (RFF) method of Kutateladze and Mukhina (KM) (J. Org. Chem. 2015, 80, 10838-10848). DFT values significantly more accurate than those obtained by KM for their comparison with RFF values can be obtained, at a lower cost, b...

Density functional theory (DFT) is now the most commonly used method of electronic structure calculation in both condensed matter physics and quantum chemistry, thanks in part to the focus it has received over the first 50 years of the Sanibel Symposium. We present a short history, and review fourteen short and easy but important lessons about nonrelativistic DFT, with some partiality but with ...

A method for the frequency estimation of complex exponential signals observed under additive white Gaussian noise is presented. Unlike competing methods based on relatively few Discrete Fourier Transform (DFT) samples, the presented technique can generate a frequency estimate by fusing the information from all DFT samples. The estimator is shown to follow the Cramer–Rao bound with a smaller sig...

A DFT-SOFM-RBFNN method is proposed to improve the accuracy of DFT calculations on Y-NO (Y = C, N, O, S) homolysis bond dissociation energies (BDE) by combining density functional theory (DFT) and artificial intelligence/machine learning methods, which consist of self-organizing feature mapping neural networks (SOFMNN) and radial basis function neural networks (RBFNN). A descriptor refinement s...

A series of tetraphenylporphyrins appended at the β-pyrrolic position with an ethynylphenylene- or ethynylpyridine-substituent have been subjected to spectroscopic and density functional theory (DFT) analyses. The mean absolute deviation between corresponding experimental and DFT-derived vibrational spectra is up to 10.2 cm(-1), suggesting that the DFT B3LYP/6-31G(d) method provides an accurate...

Highly crystalline and pure lithium metasilicate (Li2SiO3) and lithium disilicate (Li2Si2O5) nanomaterials were synthesized by hydrothermal method and characterized by PXRD technique. The changes in the morphology and particle size of the synthesized nanomaterials with reaction time were investigated using SEM technique. The UV-Vis and photoluminescence spectra of the compounds were studied. Th...