Study and Simulation of a Sensor Based on 2D Photonic Crystals for the Detection of Aromatic Compounds: C6H5I, C6H5F and C6H5Cl

A new study was presented on a new sensor based on two-dimensional photonic crystals (Phc's) to detect the following three organic materials: iodobenzene (C6H5I), fluorobenzene (C6H5F), chlorobenzene (C6H5Cl). These materials have dielectric constants (εr) equal to 2.623; 2.140; 2.318, respectively. The proposed sensor is a structure made of silicon rods submerged in air plus a ring resonator. The ring resonator is stuck between two horizontal waveguides. At the end of the ends of the structure there are four ports where port 1 and 2 belong to the top guide and port (3) and (4) the bottom one. In order to analyze the behavior of the sensor, a plane wave expansion approach (PWE) and the finite element method (FEM) are applied. Thanks to the MATLAB and COMSOL simulation software, we were able to obtain the following numerical results: the norm of the electric field, the total energy density and this last magnitude according to the refractive indices of the different organic materials used. We could observe variations in energy density for each material. So, this change is due to their refractive index which varies from one material to another. In this study, we have fixed the other parameters like the constant of the lattice "a" and the radius "r" and we are interested in the dielectric constants (εr) or more precisely the refractive index (n), the latter proves that it is one of the important parameters for detection.

The gravitational energy density of the Universe

The teleparallel gravitational energy–momentum tensor density of the Friedmann–Lemaître–Robertson–Walker spacetime is calculated and analyzed: it is decomposed into density, isotropic pressure, non-isotropic pressures, and the heat-flux 4-vector; the antisymmetric part is decomposed into “electric” and “magnetic” components. It is found that the gravitational field obeys a radiation-like equation of state, the antisymmetric part does not contribute to the gravitational energy–momentum; and the total energy density, the non-isotropic pressures and the heat-flux 4-vector vanish for spatially flat universes. Finally, it is verified that the field equations have a well-defined vacuum.

About the Origin of the Dark Energy and the Zero Mass/Energy Universe

Based on the Gravito-Electro-Magnetic (GEM) equations as another form (for low fields) of Einstein's Equations of General Relativity Theory (GRT) an equation is derived for the total energy density in the universe, including the gravitational fields, the contribution thereof is always negative and so it seems to represents the Dark Energy (DE). When calculating the total energy of the universe from this equation, the result is near to zero because of negative contributions from gravitational fields, depending a little on the available parameters of the universe as e.g. it's baryonic mass. Thus the assumption is given a high amount of probability, that the total energy (mass) in the universe is really zero and very likely is always zero. This would mean, that the universe developed from empty space-time or from nothing (may be by quantum fluctuations). Looking on the development it could be that the average energy density is zero for each sufficient large part of the universe at any time, except for very local deviations (e.g. galaxies, black holes etc.). As a consequence the expansion of the universe is probably not retarded by gravity (thus the Friedmann equation and others do not apply). The expansion of the universe can be considered as driven by the pressure of a gas-like medium with positive masses as by intergalactic gas, dust, stars and galaxies. Conclusions are drawn as to the interpretation of the formation of voids in the universe, flat space etc.

Intermediate Band Studies of Substitutional V2+, Cr2+, and Mn2+ Defects in ZnTe Alloys

We present first-principles total-energy density functional calculations to study the intermediate band states of substitutional V2+, Cr2+, and Mn2+ ions in ZnTe alloys. The intermediate band states of substitutional transition metal defects of TM2+xZn1−xTe (TM = V, Cr, Mn) alloys are examined as their atomic, structural, and electronic analysis. Our findings show that the scissor-corrected transitions due to Jahn-Teller effects lead to the wavelengths 2530 nm and 2695 nm in the emission spectra. Our findings agree with previously reported experimental results.

Adsorption of NO2 and H2S on ZnGa2O4(111) Thin Films: A First-Principles Density Functional Theory Study

We performed first-principles total-energy density functional calculations to study the reactions of NO2 and H2S molecules on Ga–Zn–O-terminated ZnGa2O4(111) surfaces. The adsorption reaction and work functions of eight NO2 and H2S adsorption models were examined. The bonding of the nitrogen atom from a single NO2 molecule to the Ga atom of the Ga–Zn–O-terminated ZnGa2O4(111) surfaces exhibited a maximum work function change of +0.97 eV. The bond joining the sulfur atom from a single H2S molecule and the Ga atom of Ga–Zn–O-terminated ZnGa2O4(111) surfaces exhibited a maximum work function change of −1.66 eV. Both results concur with previously reported experimental observations for ZnGa2O4-based gas sensors.

Dietary Fat and Energy Content of Steeped, Germinated and Unprocessed Maize Grains Meant For Complementary Feeding In Nigeria

Household technologies such as fermentation, soaking, roasting and malting are traditionally used in many societies with the assumption that they can contribute to improving the safety and quality of complementary foods. To observe the dietary lipid quality, unprocessed, steeped and germinated maize grains were used to evaluate their effect on the enhancement of fatty acids, phospholipids and phytosterols. Maize samples were denoted as B1 (unprocessed) B2 (sprouted) and B3 (steeped) maize. In crude fat, B2 was enhanced by 0.47g/100g (9.23%). Calculated fatty acids had values (g/100g) of:B1(3.66)<B2(4.00)> B3(3.63). Highest levels of these fatty acids were observed as follows: SFA(B2, 27.2%), MUFA(B1,34.7%) and PUFA(B1,47.0%); but B3 was more concentrated in MUFA and PUFA than B2 but less than B1.Both oleic and linoleic fatty acids slightly increased during steeping stage of malting but later declined during germination phase particularly oleic acid. Total energy density (kcal/100g) concentration in the samples with the percentage linoleic acid had these values: B1(32.9, 43.7%), B2(36.0, 37.2%) and B3(32.7, 41.9%). Total phytosterol (mg/100g) values were low: B1(52.3), B2(43.7) and B3(45.1) with sitosterol predominating in all: 33.5 > 28.8 < 29.6 respectively. In phospholipids, values were generally higher than the phytosterols as we have total values (mg/100g) of: B1(74.4); B2(71.3) and B3(62.0) with phosphatidylinositol predominating in all samples: 25.5 > 25.1 > 22.4 respectively. Raw maize sample had highest concentration of phospholipids, phytosterols, MUFA and PUFA. The declines in B2 and B3 in the above parameters suggested that lipids were used for biochemical processes. However, B3 was better concentrated than B2 in phytosterols, MUFA, PUFA, linoleic and oleic acids. This showed germination reduced fat content due to hydrolysis and utilization of fat as an energy source in germination. Observations had depicted the contribution of maize to presence of high level phosphatidylinositol and sitosterol to the infant. It also contributed to information on discrepancies on the effect of fermentation/ germination on cereal lipids in literature. Either steeped or sprouted maize is good as complementary food.

Ultrasonic Deicing Efficiency Prediction and Validation for a Flat Deicing System

An effective deicing system is needed to be designed to conveniently remove ice from the surfaces of structures. In this paper, an ultrasonic deicing system for different configurations was estimated and verified based on finite element simulations. The research focused on deicing efficiency factor (DEF) discussions, prediction, and validations. Firstly, seven different configurations of Lead zirconate titanate (PZT) disk actuators with the same volume but different radius and thickness were adopted to conduct harmonic analysis. The effects of PZT shape on shear stresses and optimal frequencies were obtained. Simultaneously, the average shear stresses at the ice/substrate interface and total energy density needed for deicing were calculated. Then, a coefficient named deicing efficiency factor (DEF) was proposed to estimate deicing efficiency. Based on these results, the optimized configuration and deicing frequency are given. Furthermore, four different icing cases for the optimize configuration were studied to further verify the rationality of DEF. The effects of shear stress distributions on deicing efficiency were also analyzed. At same time, a cohesive zone model (CZM) was introduced to describe interface behavior of the plate and ice layer. Standard-explicit co-simulation was utilized to model the wave propagation and ice layer delamination process. Finally, the deicing experiments were carried out to validate the feasibility and correctness of the deicing system.

Ld/Mm+ Simulation of Some Aristolochic and Humic Acids Species Coupled in Periodic Box with Water

Background: This study is one of the dynamics molecular docking that presents the interactions between a molecular model of the mixture of humic acid structure and 18 aristolochic acids structures, from PubChem database in a water box that simulates the environment reactions. Objective: The major objective was to identify what happens in this procedure(LD/MM+) with the coupled species. Method: LD/MM+ SIMULATION ( Langevin dynamics simulation) Results: The R-Squared statistic indicates that the model as fitted by MLR , explains 90.9437% of the variability in Volume. Conclusion: The interactions of these acids, the types of forces, and the way that these molecules can get closer to each other, in terms of total energy density, while identifying the specificities vis-à-vis of wateraromaticity or water-reactivity behaviors.

NMR Investigations of Crystalline and Glassy Solid Electrolytes for Lithium Batteries: A Brief Review

The widespread use of energy storage for commercial products and services have led to great advancements in the field of lithium-based battery research. In particular, solid state lithium batteries show great promise for future commercial use, as solid electrolytes safely allow for the use of lithium-metal anodes, which can significantly increase the total energy density. Of the solid electrolytes, inorganic glass-ceramics and Li-based garnet electrolytes have received much attention in the past few years due to the high ionic conductivity achieved compared to polymer-based electrolytes. This review covers recent work on novel glassy and crystalline electrolyte materials, with a particular focus on the use of solid-state nuclear magnetic resonance spectroscopy for structural characterization and transport measurements.

Hydrogen vs. Halogen Bonds in 1-Halo-Closo-Carboranes

A theoretical study of the hydrogen bond (HB) and halogen bond (XB) complexes between 1-halo-closo-carboranes and hydrogen cyanide (NCH) as HB and XB probe has been carried out at the MP2 computational level. The energy results show that the HB complexes are more stable than the XBs for the same system, with the exception of the isoenergetic iodine derivatives. The analysis of the electron density with the quantum theory of atoms in molecules (QTAIM) shows the presence of a unique intermolecular bond critical point with the typical features of weak noncovalent interactions (small values of the electron density and positive Laplacian and total energy density). The natural energy decomposition analysis (NEDA) of the complexes shows that the HB and XB complexes are dominated by the charge-transfer and polarization terms, respectively. The work has been complemented with a search in the CSD database of analogous complexes and the comparison of the results, with those of the 1-halobenzene:NCH complexes showing smaller binding energies and larger intermolecular distances as compared to the 1-halo-closo-carboranes:NCH complexes.