Population Densities Of States Research Articles

Novel use of UV broad-band excitation and stretched exponential function in the analysis of fluorescent dissolved organic matter: study of interaction between protein and humic-like components

A combination of broad-band UV radiation (UV A and UV B; 250–400 nm) and a stretched exponential function (StrEF) has been utilised in efforts towards convenient and sensitive detection of fluorescent dissolved organic matter (FDOM). This approach enables accessing the gross fluorescence spectral signature of both protein-like and humic-like components in a single measurement. Commercial FDOM components are excited with the broad-band UV excitation; the variation of spectral profile as a function of varying component ratio is analysed. The underlying fluorescence dynamics and non-linear quenching of amino acid moieties are studied with the StrEF (exp(-V[Q]β)). The complex quenching pattern reflects the inner filter effect (IFE) as well as inter-component interactions. The inter-component interactions are essentially captured through the ‘sphere of action’ and ‘dark complex’ models. The broad-band UV excitation ascertains increased excitation energy, resulting in increased population density in the excited state and thereby resulting in enhanced sensitivity.

Higher USA State Resident Neuroticism Is Associated With Lower State Volunteering Rates.

Highly neurotic persons have dispositional characteristics that tend to precipitate social anxiety that discourages formal volunteering. With the 50 American states as analytical units, Study 1 found that state resident neuroticism correlated highly ( r = -.55) with state volunteering rates and accounted for another 26.8% of the volunteering rate variance with selected state demographics controlled. Study 2 replicated Study 1 during another period and extended the association to college student, senior, secular, and religious volunteering rates. Study 3 showed state resident percentages engaged in other social behaviors involving more familiarity and fewer demands than formal volunteering related to state volunteering rates but not to neuroticism. In Study 4, state resident neuroticism largely accounted statistically for relations between state volunteering rates and state population density, collectivism, social capital, Republican preference, and well-being. This research is the first to show that state resident neuroticism is a potent predictor of state volunteering rates.

An important rule for realizing metal → half-metal → semiconductor transition in single-molecule junctions

Recently, Zhong et al (2015 Nano Lett. 15 8091) found that two additional hydrogen atoms can be adsorbed to the opposite aza-bridging nitrogen atoms of the manganese phthalocyanine (MnPc) macrocycle when exposed to H2. Thus the symmetry of the MnPc molecule is changed from 4-fold to 2-fold. Motivated by this recent experiment, we theoretically investigate a MnPc-based single-molecule junction in this work and propose a simple and reliable way to realize the transition of its electronic properties. On the basis of spin-polarized density-functional theory calculations combined with the Keldysh nonequilibrium Green’s technique, we find that the gradual hydrogenation in MnPc molecules gives rise to the changes of the hardness of the electron density and spin-selective orbital decoupling, which eventually leads to the realization of the first ever metal → half-metal → semiconductor transition behavior in single-molecule junctions. Analysis of molecular projected self-consistent Hamiltonian, Mulliken population, and local density of states also reveals an important rule for realizing this transition behavior. Our research confirms that the hydrogenation of MnPc molecules can realize various molecular functionalities in unitary material background.

Regional Variation in Rates of IVF Treatment across Australia: A Population-based Study.

Background: There is variation in uptake of in vitro fertilisation (IVF) between countries, and Australia has high incidence rates of IVF due to universal public funding. However, it remains unclear whether there is regional variation and, if present, what might cause this.Objectives: We sought to determine whether regional variations in treatment rates existed and what might influence these.Methods: The number of cycles of fresh IVF and intrauterine insemination (IUI) for women were obtained for the period 2011 until 2014 in two age groups (25 to 34 years and 35 to 44 years) to calculate incidence rates. Proxy indicators that might influence treatment affordability were: unemployment rates; average weekly total earnings; coverage of private health insurance; and, percentage of women in the highest socioeconomic quintile. Measures of accessibility considered were percentage of the population remote from urban areas and average state population density. Linear regressions were performed using log-transformed ratio of IVF and IUI incidence rates.Results: Variations were found in IVF uptake between states with greater differences in older women. There was no significant association between IVF procedures and population density or geographic isolation. Economic factors were not associated with IVF uptake.Conclusion: These findings suggest that factors such as physician preference, clinical practice guidelines, and cryopreservation protocols of ART units might explain the national variation in uptake of IVF.

Stochastic Liouville equation for particles driven by dichotomous environmental noise.

We analyze the stochastic dynamics of a large population of noninteracting particles driven by a global environmental input in the form of a dichotomous Markov noise process (DMNP). The population density of particle states evolves according to a stochastic Liouville equation with respect to different realizations of the DMNP. We then exploit the connection with previous work on diffusion in randomly switching environments, in order to derive moment equations for the distribution of solutions to the stochastic Liouville equation. We illustrate the theory by considering two simple examples of dichotomous flows, a velocity jump process and a two-state gene regulatory network. In both cases we show how the global environmental input induces statistical correlations between different realizations of the population density.

OBSERVATIONS AND SIMULATIONS OF THE Na i D1 LINE PROFILES IN AN M-CLASS SOLAR FLARE

ABSTRACT We study the temporal evolution of the Na i D1 line profiles in the M3.9 flare SOL2014-06-11T21:03 UT, using observations at high spectral resolution obtained with the Interferometric Bidimensional Spectrometer instrument on the Dunn Solar Telescope combined with radiative hydrodynamic simulations. Our results show a significant increase in the intensities of the line core and wings during the flare. The analysis of the line profiles from the flare ribbons reveals that the Na i D1 line has a central reversal with excess emission in the blue wing (blue asymmetry). We combine RADYN and RH simulations to synthesize Na i D1 line profiles of the flaring atmosphere and find good agreement with the observations. Heating with a beam of electrons modifies the radiation field in the flaring atmosphere and excites electrons from the ground state 3s 2S to the first excited state 3p 2P, which in turn modifies the relative population of the two states. The change in temperature and the population density of the energy states make the sodium line profile revert from absorption into emission. Furthermore, the rapid changes in temperature break the pressure balance between the different layers of the lower atmosphere, generating upflow/downflow patterns. Analysis of the simulated spectra reveals that the asymmetries of the Na i D1 flare profile are produced by the velocity gradients in the lower solar atmosphere.

Багаторічна динаміка щільності стану розвитку міжвидових популяцій злакових попелиць (Homoptera, Aphididae) упродовж вегетації пшениці озимої в умовах Лісостепу України

Багаторічна динаміка щільності стану розвитку міжвидових популяцій злакових попелиць (Homoptera, Aphididae) упродовж вегетації пшениці озимої в умовах Лісостепу України

Quantitative Emission Spectroscopy for Superorbital Reentry in Expansion Tube X2

A superorbital reentry flow was realized in the X2 expansion tunnel of the Centre for Hypersonics of the University of Queensland, resulting in measurements of electronic excitation temperature, electron density, and particle densities of neutral and ionized atomic nitrogen and oxygen. A rectangular cold wall model was exposed to a flow corresponding to a flight equivalent velocity. Vacuum ultraviolet optical emission spectroscopy in the wavelength range between 116 and 185 nm was conducted through a window at the stagnation point. Spatially resolved optical emission spectroscopy of the stagnation streamline in the near-infrared wavelength range from 695 to 880 nm was conducted, analyzing the flow from the side. Population densities of excited atomic states, electronic excitation temperatures, and electron and ion densities were determined by analyzing the radiative transport in the flowfield. Additionally, the flowfield was numerically simulated using the code URANUS. Agreement in electron density () and electron temperature () in the equilibrium region is observed between the numerical simulations and the measurement. Significant differences between measurement and simulation in the distribution of the electron temperature at the shock are attributed to the modeling of the URANUS electron temperature.

Financial inclusion in India: an application of TOPSIS

PurposeThe purpose of this paper is to combine the critical parameters used to study financial inclusion into a composite index. The idea is to rank Indian states and union territories (UTs) on the basis of this index, determine change in ranks during 2011 to 2014 and identify factors affecting high/low scores on the index.Design/methodology/approachData for the study were collected from secondary sources published by Reserve Bank of India (RBI) and Central Statistical Organization. Applying technique of order preference by similarity to ideal solution (TOPSIS), a composite multi-dimensional index of financial inclusion (IFI) has been built by using three broad parameters of penetration, availability and usage of banking services. Factors significantly influencing scores of states/UTs on IFI were identified using multiple regression analysis.FindingsThe value of financial inclusion for India on composite IFI has increased by 0.045 points during the study period. Share of agriculture to state gross domestic product, literacy ratio, population density, infrastructure development and farmer suicides are significant factors affecting financial inclusion.Practical implicationsThe multi-dimensional IFI is a useful tool to measure financial inclusion using several parameters for various states/regions. The index can also be used to compare the performance of states/regions over same/different periods.Originality/valueThis paper is unique in its attempt to construct multi-dimensional IFI for Indian states/UTs by applying TOPSIS. It will prove useful for future researchers by combining several aspects of financial inclusion into single index.

Effect of boron doping in sumanene frame toward hydrogen physisorption: A theoretical study

Because of carbon-based materials have shown excellent results for the adsorption of hydrogen as an energy source, in this study, adsorption properties of 26 boron disubstituted sumanene isomers were investigated using MP2/6-311++G(d,p)//B3LYP/6-31+G(d) level of theory. The influence of sumanene modifications on its adsorption properties towards the hydrogen molecule was evaluated and zero point energy (ZPE) and basis set superposition error (BSSE) corrections were applied to calculate interaction energies (IE). Molecular electrostatic potential (MEP) surfaces were also employed to better understanding the adsorption sites and additional details about adsorption. The adsorption properties were discussed by using density of states (DOS), projected density of states (PDOS), overlap population density of states (OPDOS) and natural bond orbital (NBO) analysis. Stability and reactivity, natural population analysis (NPA), dipole moment, HOMO–LUMO gap (HLG) and bowl depth of the isomers were discussed and temperature effects on the interaction energy were evaluated. The results indicate a physisorption mechanism and insignificant perturbation of isomers after adsorption. Also, respect to position of boron atoms in frame of sumanene, interaction energy increases or decreases in comparison with pristine sumanene. The best and the worst isomers and the best and the worst classes of isomers were proposed for future experimental studies.

Adsorption properties of CO, H2 and CH4 over Pd/γ-Al2O3 catalyst: A density functional study

Density functional theory (DFT) calculations were employed to investigate the adsorption characteristics of carbon monoxide (CO), hydrogen (H2), and methane (CH4) on the surface of clean γ-Al2O3 and Pd supported γ-Al2O3, which is of significant for catalytic combustion. The adsorption intensities of the three gas molecules in pure γ-Al2O3 (1 1 0) and Pd/γ-Al2O3 (1 1 0) were in the order of CO>H2>CH4. The corresponding adsorption energies on the Pd/γ-Al2O3 (1 1 0) surface were at least three times higher than those on γ-Al2O3 (1 1 0). Anlysis of Mulliken population and partial density of states (PDOS) showed that the adsorption mechanisms were as follow: (a) CO stably adsorbed on the bridge site of dimer Pd with two CPd bonds because of charges transfer from the surface to CO, and the triple bond (CO) was broken to a double bond (CO); (b) H2 was dissociated into hydrogen atoms on the dimer Pd and produced a stable planar configuration; and (c) the tetrahedral structure of CH4 was destroyed on the surface and formed a CH3 species bonded to the Pd atom, which contributes to the orbital hybridization between C and Pd atoms.

Study of Ar and Ar-CO2 microwave surfaguide discharges by optical spectroscopy

A surfaguide microwave discharge operating at 2.45 GHz in Ar and Ar-CO2 mixtures is studied using diagnostics methods based on optical emission spectroscopy. The population densities of Ar metastable and resonant states of the lowest group of excited levels (1sx) are investigated for several experimental conditions using the self-absorption technique. It is found that the densities of these levels, ranging from 1017 to 1016 m−3 for the pure Ar case, are dependent on the discharge pressure and applied power. The electron temperature and electron density are calculated via the balances of creation/loss mechanisms of radiative and metastable levels. In the range of the studied experimental conditions (50–300 W of applied power and 0.5–6 Torr of gas pressure), the results have shown that lower values of electron temperature correspond to higher values of power and pressure in the discharge. Adding CO2 to the argon plasma results in a considerable decrease (about 3 orders of magnitude) of the Ar metastable atom density. The feasibility of using the ratio of two Ar emission line intensities to measure the electron temperature in CO2 discharges with small Ar admixtures is studied.

Theoretical investigation of nonthermal equilibrium exciton dynamics in GaN using hydrogen plasma model

As a basis of the study on exciton stability under a nonthermal equilibrium state, the excitation and deexcitation population fluxes and population densities of several states of the principal quantum number p are calculated using a hydrogen plasma model for various electron excitation densities and temperatures of the lattice, electron, and exciton. It is found that the balance of the excitation and deexcitation population fluxes depends on the p number. At a lower-lattice-temperature region, ladderlike deexcitation flux is dominant for low p states, while the quasi-Saha–Boltzmann relation holds for high p states. At temperatures higher than 150 K, the exciton formation and dissociation fluxes become dominant. Exciton dissociation is enhanced at temperatures higher than approximately 120 K. This process is triggered by the excitation between the states of p = 1 and 2. High- and low-order states sometimes exhibit different population flow characteristics, which reveal the exciton dissociation dynamics.

Spectroscopic studies on 9H-carbazole-9-(4-phenyl) boronic acid pinacol ester by DFT method

9H-Carbazole-9-(4-phenyl) boronic acid pinacol ester (9-CPBAPE) molecule was investigated by FT-IR, Raman, UV–vis, 1H and 13C NMR spectra. FT-IR, FT-Raman and dispersive Raman spectra were recorded in the solid phase. 1H, 13C NMR and UV–vis spectra were recorded in dimethyl sulfoxide (DMSO) solution. The results of theoretical calculations for the spectra of the title molecule were compared with the experimental spectra. The highest occupied molecular orbital (HOMO) the lowest unoccupied molecular orbital (LUMO) and molecular electrostatic potential (MEP) analyses were performed. The theoretical calculations for the molecular structure and spectroscopic studies were performed with DFT (B3LYP) and 6-311G (d,p) basis set calculations using the Gaussian 09 program. The total (TDOS), partial (PDOS) density of state and overlap population density of state (OPDOS) diagrams analyses were performed using GaussSum 2.2 program.

Spatial Panel VAR and Application to Forecast Influenza Incidence Rates of US States

In this paper, we propose a spatial panel vector autoregression, SPVAR(p), which generalizes the spatial dynamic panel data (SDPD) models with individual fixed effects to allow for multivariate vector observations and higher order lags. The regression residuals can be independently or spatial autoregressively (SAR) distributed. We investigate in the issues of identification and estimation via profile QMLE. We prove that the QML estimators are consistent and asymptotically normally distributed when both N and T are large. Then, we analyze the bias and bias correction. The finite sample performance of the profile QMLE is evaluated by Monte Carlo simulations. Information criteria and likelihood ratio test are used to select the lag orders and test the residual specifications in the SPVAR(p). The SPVAR(p) is then used to estimate and forecast the incidence rates of influenza like illness (ILI) in the United States. We combine weekly ILI incidence rate data by Google Flu Trends and the office of Centers for Disease Control and Prevention (CDC) into a vector measure for 48 US continental states, and then we use the vector observations to estimate the SPVAR(p) model, where the spatial weight matrix is the row normalized state geographical adjacency matrix. We use state population density, temperature, and precipitation as predictors. We find that SPVAR(p) achieves satisfactory in-sample estimates and out-of-sample forecasts based on Google Flu Trends and CDC ILI incidence rate data. The estimated SPVAR(p) is compared against univariate SDPD(p) model of Google Flu Trends ILI incidence rates. We also conduct an impulse response analysis of the dynamic diffusions of California flu shock.

Systematic analysis of structural and spectroscopic properties of neptunimine (HN=NpH2) and plutonimine (HN=PuH2).

The structures, stabilities, nature of bonding, and spectroscopic properties of the new actinide imine molecules, neptunimine (HN=NpH2) and plutonimine (HN=PuH2), in the gas phase have been systematically explored at different levels of theory. Our calculation indicates that HN=AnH2 (An=Np, Pu) should be nonplanar and have a quartet ([Formula: see text]) and quintet ([Formula: see text]) ground state, respectively. The nature of the chemical bonding in these molecules were investigated by employing topological methods including electron localization function (ELF), atoms in molecules (AIM) as well as natural bond orbital analysis (NBO). The results showed that these actinide complexes possess relatively strong An=N multiple bonds between the An 6d-5f hybrid orbitals with N 2s-2p orbitals. The charge decomposition analysis (CDA) diagram demonstrated that the transition of electrons mainly happened inside the AnH2 of HN=AnH2. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (OPDOS) diagrams analysis were implemented. The IR and Raman spectra were theoretically simulated as a convenient way to confirm the existence of the actinide imine complexes in further experiments.

A collisional radiative model of hydrogen plasmas developed for diagnostic purposes of negative ion sources.

A collisional radiative model of low-pressure hydrogen plasmas is elaborated and applied in optical emission spectroscopy diagnostics of a single element of a matrix source of negative hydrogen ions. The model accounts for the main processes determining both the population densities of the first ten states of the hydrogen atom and the densities of the positive hydrogen ions H(+), H2 (+), and H3 (+). In the calculations, the electron density and electron temperature are varied whereas the atomic and molecular temperatures are included as experimentally obtained external parameters. The ratio of the Hα to Hβ line intensities is calculated from the numerical results for the excited state population densities, obtained as a solution of the set of the steady-state rate balance equations. The comparison of measured and theoretically obtained ratios of line intensities yields the values of the electron density and temperature as well as of the degree of dissociation, i.e., of the parameters which have a crucial role for the volume production of the negative ions.

The spectroscopic (FT-IR, FT-Raman, dispersive Raman and NMR) study of ethyl-6-chloronicotinate molecule by combined density functional theory

In this study, ethyl-6-chloronicotinate (E-6-ClN) molecule is recorded in the region 4000–400cm−1 and 3500–100cm−1 (FT-IR, FT-Raman and dispersive Raman, respectively) in the solid phase. 1H and 13C nuclear magnetic resonance (NMR) spectra are recorded in DMSO solution. The structural and spectroscopic data of the molecule are obtained for two possible isomers (S1 and S2) from DFT (B3LYP) with 6-311++G(d,p) basis set calculations. The geometry of the molecule is fully optimized, vibrational spectra are calculated and fundamental vibrations are assigned on the basis of the potential energy distribution (PED) of the vibrational modes. 1H and 13C NMR chemical shifts are calculated by using the gauge-invariant atomic orbital (GIAO) method. The electronic properties, such as excitation energies, oscillator strengths, wavelengths, HOMO and LUMO energies, are performed by time-dependent density functional theory (TD-DFT). Total and partial density of state and overlap population density of state diagrams analysis are presented for E-6-ClN molecule. Furthermore, frontier molecular orbitals (FMO), molecular electrostatic potential, and thermodynamic features are performed. In addition to these, reduced density gradient of the molecule is performed and discussed. As a conclusion, the calculated results are compared with the experimental spectra of the title compound. The results of the calculations are applied to simulate the vibrational spectra of the molecule, which show excellent agreement with the observed ones. The theoretical and tentative results will give us a detailed description of the structural and physicochemical properties of the molecule. Natural bond orbital analysis is done to have more information stability of the molecule arising from charge delocalization, and to reveal the information regarding charge transfer within the molecules.

Quantum Mechanical Study of Substituent Dependence on the Structure, Spectroscopic (13C, 1H NMR and UV), NBO, Hyperpolarizability and HOMOLUMO Analysis of Ru(NHC)2Cl2(CH‐p‐C6H4X) Complexes

AbstractIn this work, we have explored the structural, electronic properties, 13C and 1H NMR parameters and first hyperpolarizability of Ru(NHC)2Cl2(CH‐p‐C6H4X) complexes (XH, F, Cl, Me, NH2, OH, CN, NO2, CHO, COOH) by mpw1pw91 quantum method. The X‐substituent effect on structural parameters, frontier orbital energies, spectroscopic (1H and 13C NMR, UV) of complex was carried out. The results indicate that the substituent has played a significant role on the structures and properties of complex. 1H and 13C NMR chemical shifts were calculated by using the gauge‐invariant atomic orbital (GIAO) method. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (OPDOS) diagrams analysis were exhibited. In analyzing the bonding characteristics of this structure, Ru‐Ccarbene and Ru‐CNHC bonds were identified and characterized in details by Natural bond orbital (NBO) analysis.

Magnetic ordering and electronic structure of the ternary iron arsenide BaFe2As2

In this paper, we report structural parameters, magnetic ordering and the electronic structure of the tetragonal and orthorhombic ternary iron arsenide compound [Formula: see text]. Ab initio calculations are performed by the means of full-potential linearized augmented plane waves plus local orbitals method for both spin states. The local spin density plus Hubbard potential ([Formula: see text]) and generalized gradient plus Hubbard potential ([Formula: see text]) approximations are used to treat the exchange and correlation potentials. The results mainly show that orthorhombic [Formula: see text] compound has an antiferromagnetic spin ordering. Both spin-up and spin-down polarizations are considered to investigate the band structure, density of states and electron charge density. High density of states population at the Fermi level reveals metallic character of this material. The magnetism property arises essentially from the [Formula: see text] orbital of iron atom.