Nonclassical Radiation from Two Atoms and Quantum Search Algorithms

We discuss the non-classical aspects of the radiation emitted from a system of two atoms. We first consider the radiation emitted from independently radiating quantum systems. If the atoms are excited by coherent light then the radiation exhibits the usual interference fringes in the far field as the point of observation is varied. By contrast,if the system is incoherently excited no interferences can be seen in the far held intensity pattern, 1. e. tne first order correlation function. However, if the second order correlation function is considered interferences appear even if the system is incoherently excited, i.e. even if the emitted photons are uneorrelated .This can be understood in terms of interferences between multiple pathways for quantum transitions as well as the detection induced entanglement. We show the non-classical nature of these intensity-intensity correlations. Such quantum interferences can be used for range of applications, i.e. for information processing or in applications to quantum search algorithms.We also consider the ease when the atoms are dose to each other so that the dipole-dipole interaction between them is significant. In this ease it is demonstrated that as a function of the detector position we can probe the decay either in the symmetric space or in the antisymmetrie space.     

The Number of Congruent Simplices in a Point Set

Abstract. For 1 ≤ k≤ d-1 , let f _k ^(d) (n) be the maximum possible number of k -simplices spanned by a set of n points in R ^d that are congruent to a given k -simplex. We prove that f ₂ ⁽³⁾ (n) = O(n ^5/3 2 ^O(α2(n)) ) , f ₂ ⁽⁴⁾ (n) = O(n^ 2+ ɛ ) , for any ɛ >0 , f ₂ ⁽⁵⁾ (n) = Θ(n ^7/3 ) , and f ₃ ⁽⁴⁾ (n) = O(n^ 20/9+ ɛ ) , for any ɛ >0 . We also derive a recurrence to bound f _k ^(d) (n) for arbitrary values of k and d , and use it to derive the bound f _k ^(d) (n) = O(n^ d/2+ ɛ ) , for any ɛ >0 , for d ≤ 7 and k ≤ d-2 . Following Erdos and Purdy, we conjecture that this bound holds for larger values of d as well, and for k≤ d-2 .     

Structural and stability studies of CdS and SnS nanostructures synthesized by various routes

CdS nanorods and SnS nano-flakes have been synthesized by solvothermal process and CdS nanoparticles have been synthesized by aqueous media process. Structural properties of these nanocomposites are performed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Chemical purity of these nanocomposites has been confirmed by energy dispersive analysis of X-ray (EDAX). Thermal stability of these nanocomposites is investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Different parameters such as activation energy (E) for the degradation, Arrhenius parameter (A) and the entropy change (ΔS) have been calculated by Coats-Redfern and Satava model. It is observed that the activation energy of the CdS nanorods is much higher compared to that of CdS nanoparticles and SnS nano-flakes.     

Rapid Polyolefin Hydrogenolysis by a Single-Site Organo-Tantalum Catalyst on a Super-Acidic Support: Structure and Mechanism

The novel electrophilic organo-tantalum catalyst AlS/TaNp_x ( 1 ) (Np=neopentyl) is prepared by chemisorption of the alkylidene Np₃Ta=CH^tBu onto highly Brønsted acidic sulfated alumina (AlS). The proposed catalyst structure is supported by EXAFS, XANES, ICP, DRIFTS, elemental analysis, and SSNMR measurements and is in good agreement with DFT analysis. Catalyst 1 is highly effective for the hydrogenolysis of diverse linear and branched hydrocarbons, ranging from C2 to polyolefins. To the best of our knowledge, 1 exhibits one of the highest polyolefin hydrogenolysis activities (9,800 (CH₂ units) ⋅ mol(Ta)⁻¹ ⋅ h⁻¹ at 200 °C/17 atm H₂) reported to date in the peer-reviewed literature. Unlike the AlS/ZrNp₂ analog, the Ta catalyst is more thermally stable and offers multiple potential C−C bond activation pathways. For hydrogenolysis, AlS/TaNp_x is effective for a wide variety of pre- and post-consumer polyolefin plastics and is not significantly deactivated by standard polyolefin additives at typical industrial concentrations.     

Surrogate optimization of deep neural networks for groundwater predictions

Sustainable management of groundwater resources under changing climatic conditions require an application of reliable and accurate predictions of groundwater levels. Mechanistic multi-scale, multi-physics simulation models are often too hard to use for this purpose, especially for groundwater managers who do not have access to the complex compute resources and data. Therefore, we analyzed the applicability and performance of four modern deep learning computational models for predictions of groundwater levels. We compare three methods for optimizing the models’ hyperparameters, including two surrogate model-based algorithms and a random sampling method. The models were tested using predictions of the groundwater level in Butte County, California, USA, taking into account the temporal variability of streamflow, precipitation, and ambient temperature. Our numerical study shows that the optimization of the hyperparameters can lead to reasonably accurate performance of all models (root mean squared errors of groundwater predictions of 2 meters or less), but the “simplest” network, namely a multilayer perceptron (MLP) performs overall better for learning and predicting groundwater data than the more advanced long short-term memory or convolutional neural networks in terms of prediction accuracy and time-to-solution, making the MLP a suitable candidate for groundwater prediction.

     

Proanthocyanidins Modulate Rumen Enzyme Activities and Protein Utilization In Vitro

This study investigated the principal leaf protein (rubisco) solubilization and in vitro ruminal enzyme activity in relation to the molecular structure of proanthocyanidins extracted from leaves of Anogeissus pendula and Eugenia jambolana. Six proanthocyanidin fractions were extracted by 50% (v/v) methanol–water followed by 70% (v/v) acetone–water and then distilled water from leaves of A. pendula (AP) and E. jambolana (EJ) to yield EJ–70, EJ–50, EJ–DW, AP–70, AP–50 and AP–DW. Fractions were examined for their molecular structure and their effects on sheep ruminal enzymes and solubilization of rubisco in vitro. All fractions significantly (p < 0.05) inhibited the activity of ruminal glutamic oxaloacetic transaminase and glutamic pyruvic transaminase. The fractions AP–50 and EJ–50 significantly inhibited the activity of the R-cellulase enzyme. Most of the fractions inhibited R-glutamate dehydrogenase activity (p < 0.05) by increasing its concentration, while protease activity decreased by up to 58% with increasing incubation time and concentration. The solubilization of rubisco was observed to be comparatively higher in A. pendula (16.60 ± 1.97%) and E. jambolana (15.03 ± 1.06%) than that of wheat straw (8.95 ± 0.95%) and berseem hay (3.04 ± 0.08%). A significant (p < 0.05) increase in protein solubilization was observed when wheat straw and berseem hay were supplemented with A. pendula and E. jambolana leaves at different proportions. The efficiency of microbial protein was significantly (p < 0.05) greater with the supplementation of leaves of A. pendula in comparison to E. jambolana. The overall conclusion is that the proanthocyanidins obtained from E. jambolana exhibited greater inhibitory activities on rumen enzymes, whereas A. pendula recorded higher protein solubilization. Thus, PAs from A. pendula and E. jambolana appear to have the potential to manipulate rumen enzyme activities for efficient utilization of protein and fiber in ruminants.     

Nonlinear Neutral Delay Differential Equations of Fourth-Order: Oscillation of Solutions

The objective of this paper is to study oscillation of fourth-order neutral differential equation. By using Riccati substitution and comparison technique, new oscillation conditions are obtained which insure that all solutions of the studied equation are oscillatory. Our results complement some known results for neutral differential equations. An illustrative example is included.     

Role of Layer-by-Layer Deposition on Electrical and Optical Properties of PEDOT: PSS/Polyaniline Thin Films for Solar Cells

In this article, electrical and optical properties of PEDOT:PSS/Polyaniline: (PANI)bilayer thin films deposited on indium tin oxide (ITO) are reported. Spin coater has been used for fabrication of thin films of 40–50 nm thickness at 5000 rpm. The deposited thin films have been characterized by using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), UV-vis spectroscopy and Keithley electrometer. Layer-by-layer (LBL) technique has been shown to produce electroactive polymer films with low roughness, excellent uniformity, and high electrical conductivity for heterojunction solar cells. The electrical response of fabricated films showing ohmic behavior for PEDOT: PSS/PANI thin films.