Mesoscopic Behavior Near a Two-Dimensional Metal-Insulator Transition

We study conductance fluctuations in a two-dimensional electron gas as a function of chemical potential (or gate voltage) from the strongly insulating to the metallic regime. Power spectra of the fluctuations decay with two distinct exponents (1/v_l and 1/v_h). For conductivity $\sigma\sim 0.1 e^{2}/h$, we find a third exponent (1/v_i) in the shortest samples, and non-monotonic dependence of v_i and v_l on \sigma. We study the dependence of v_i, v_l, v_h, and the variances of corresponding fluctuations on \sigma, sample size, and temperature. The anomalies near $\sigma\simeq 0.1 e^{2}/h$ indicate that the dielectric response and screening length are critically behaved, i.e. that Coulomb correlations dominate the physics.Comment: Revised according to referee remark

Optical Emission Lines and the X-Ray Properties of Type 1 Seyfert Galaxies

In this contribution we report on the study of the optical emission lines and X-ray spectra of a sample of Type 1 AGNs, collected at the Sloan Digital Sky Survey database and observed by the XMM Newton satellite. Exploiting the different instruments carried onboard XMM, we identify the spectral components of the soft and hard energy bands (in the range from 0.3 keV up to 10 keV). The properties of the X-ray continuum and of the Fe Kalpha line feature are investigated in relation to the optical broad emission line profiles and intensity ratios. The resulting picture of emission, absorption and reflection processes is interpreted by means of a BLR structural model that was developed on the basis of independent optical and radio observations.Comment: 6 pages, 3 figures, Proceedings of the VIII Serbian Conference on Spectral Line Shapes in Astrophysics, accepted for publication on Baltic Astronomy. Corrected typos in V

A new model for the structure of the DACs and SACs regions in the Oe and Be stellar atmospheres

In this paper we present a new mathematical model for the density regions where a specific spectral line and its SACs/DACs are created in the Oe and Be stellar atmospheres. In the calculations of final spectral line function we consider that the main reasons of the line broadening are the rotation of the density regions creating the spectral line and its DACs/SACs, as well as the random motions of the ions. This line function is able to reproduce the spectral feature and it enables us to calculate some important physical parameters, such as the rotational, the radial and the random velocities, the Full Width at Half Maximum, the Gaussian deviation, the optical depth, the column density and the absorbed or emitted energy. Additionally, we can calculate the percentage of the contribution of the rotational velocity and the ions' random motions of the DACs/SACs regions to the line broadening. Finally, we present two tests and three short applications of the proposed model.Comment: 9 pages, 5 figures, accepted for publication in PAS

Are Boltzmann Plots of Hydrogen Balmer lines a tool for identifying a subclass of S1 AGN?

It is becoming clear that we can define two different types of nearby AGN belonging to the Seyfert 1 class (S1), on the basis of the match of the intensities of their Broad Balmer Lines (BBL) with the Boltzmann Plots (BP). These two types of S1 galaxies, that we call BP-S1 and NoBP-S1, are characterized, in first approximation, by Broad Line Regions (BLR) with different structural and physical properties. In this communication, we show that these features can be well pointed out by a multi-wavelength analysis of the continuum and of the broad recombination Hydrogen lines, that we carry out on a sample of objects detected at optical and X-ray frequencies. The investigation is addressed to verify whether BP-S1 are the ideal candidates for the study of the kinematical and structural properties of the BLR, in order to derive reliable estimates of the mass of their central engine and to constrain the properties of their nuclear continuum spectrum.Comment: 26 pages, 4 figures (1 multi-paged). Accepted for publication on Advances in Space Research. Contribution to the IX SCSLS

Influence of vine loads with fertile buds on grape yield and quality of variety ŽiŽak in podgorica vineyard area

Results of a two-year study of the influence of different vine loads with fertile buds on elements of grape yield and quality of Žižak grape variety are presented in this paper. The research was conducted in the Podgorica sub region, at the Lješkopolje site. Four different vine loads with fertile buds were applied: 14 buds, 18 buds, 20 and 24 buds per vine. The results of this research show that the applied loads significantly influence the examined parameters of the autochthonous variety Žižak. The highest percentage of developed and fertile shoots, as well as the average number of flowers per bud, had a variant with load of 14 buds. The relative coefficient of yielding in all examined load variants had mean values. In terms of the number of flowers per fertile shoot in the two-year average, variants with a load of 18 and 14 buds (1.44 and 1.39) stood out. The highest yield of grapes in the two-year average had the variant with a load of 24 buds-3.60 kg/vine, while the highest bunch weight had the variant V1-185 g. The quality of grapes also varied significantly under the influence of the vine load with fertile buds. The highest sugar content in must had variant with a load of 18 buds (22.32%), while the highest acid content (6.27g/l) was recorded in the variant with 24 buds per vine

Analysis of hip joint loading during walking with different shoe types using instrumented total hip prostheses

Hip joint loads need careful consideration during postoperative physiotherapy after joint replacement. One factor influencing joint loads is the choice of footwear, but it remains unclear which footwear is favorable. The objective of the present study was to investigate the influence of footwear on hip joint loads in vivo. Instrumented hip endoprostheses were used for in vivo load measurements. The parameters resultant contact force (F-res), bending moment (M-bend) and torsional moment (M-tors) were evaluated during treadmill walking at 4 km/h with different shoe types. In general, footwear tended to increase hip joint loading, with the barefoot shoe having the least influence. F-res and M-bend were significantly increased during heel strike for all shoe types in comparison to barefoot walking, with everyday shoe (34.6%; p=0.028 and 47%; p=0.028, respectively) and men's shoe (33.2%; p=0.043 and 41.1%; p=0.043, respectively) resulting in the highest changes. M-tors at AbsMax was increased by all shoes except for the barefoot shoe, with the highest changes for men's shoe (+17.6%, p=0.043) and the shoe with stiffened sole (+17.5%, p=0.08). Shoes, especially those with stiff soles or elaborate cuishing and guiding elements, increase hip joint loads during walking. The influence on peak loads is higher for M-tors than for F-res and M-bend. For patients in which a reduction of hip joints loads is desired, e.g. during physiotherapy after recent surgery or to alleviate symptoms of osteoarthritis, low profile shoes with a flexible sole may be preferred over shoes with a stiff sole or elaborate cushioning elements

Effects of long-term fertilization on yield of siderates and organic matter content of soil in the process of recultivation

The aim of this research was to determine the possibility of increasing organic matter content in humusless deposol topsoil and forming of a more favourable adsorptive complex by introducing green manure. Green manure biomass came from these compound plant species: winter rye + common vetch, forage pea + rapeseed mustard and Sudan grass. Compound feed was sown on degraded soil (type deposol) of the Stanari coal mine. Applied cultivation practices included primary and secondary tillage and additional plant nutrition. Mineral fertilizers were applied: NPK 7:20:30 (400 kg ha(-1)) and CAN 27% (200 kg ha(-1)). One of the treatments included addition of bentonite clay as absorbent of nutrients. During intensive vegetation the growth of the green biomass was measured, the crops were harvested, cut and ploughed in deposol topsoil. Organic matter content in deposol was determined when soil samples were taken 6 months after green manure incorporation. The results show that the mineral fertilization of siderates significantly increased green biomass yield and Sudan grass gave two cuts, which positively affected the increase of organic matter content in soil

Canonical approach to 2D induced gravity

Using canonical method the Liouville theory has been obtained as a gravitational Wess-Zumino action of the Polyakov string. From this approach it is clear that the form of the Liouville action is the consequence of the bosonic representation of the Virasoro algebra, and that the coefficient in front of the action is proportional to the central charge and measures the quantum braking of the classical symmetry.Comment: RevTeX, 19 page

Morphological characterization of sweet sorghum genotypes across environments

Sweet sorghum being a C4 crop accumulates more sugar in its stalks, also suitable for biofuel production and has high degree of tolerance to biotic and abiotic stresses. Morphological characteristics i.e., plant height, plant biomass, leaves on the stem, panicle length and yield of crude biomass of sweet sorghum genotypes were studied across different environments. Environments and genotype by environment interaction (GEI) had a significant effect on the yield of crude biomass. The smallest yield of crude biomass was achieved in 2016 (42.54 t ha(-1)), which was found significantly lower as compared to that in 2014 and 2015. The average plant height had a significant and positive correlation with the number of leaves (0.54) and number of leaves had highly a significant and positive correlation with the mass of stem (0.46) and panicle length (0.61). Biomass yield was positively and significantly correlated with precipitation (0.72) and negatively significantly correlated with temperature (-0.57). In breeding of sweet sorghum, the highest attention should be given to biomass yield as it manage the whole variation and controlled by polygenes

Detailed Analysis of Balmer Lines in a Sloan Digital Sky Survey Sample of 90 Broad Line Active Galactic Nuclei

In order to contribute to the general effort aiming at the improvement of our knowledge about the physical conditions within the Broad Line Region (BLR) of Active Galactic Nuclei (AGN), here we present the results achieved by our analysis of the spectral properties of a sample of 90 broad line emitting sources, collected at the Sloan Digital Sky Survey (SDSS) database. By focusing our attention mainly onto the Balmer series of hydrogen emission lines, which is the dominant feature in the optical wavelength range of many BLR spectra, we extracted several flux and profile measurements, which we related to other source properties, such as optical continuum luminosities, inferred black hole masses, and accretion rates. Using the Boltzmann Plot method to investigate the Balmer line flux ratios as a function of the line profiles, we found that broader line emitting AGN typically have larger H_alpha / H_beta and smaller H_gamma / H_beta and H_delta / H_beta line ratios. With the help of some recent investigations, we model the structure of the BLR and we study the influence of the accretion process on the properties of the BLR plasma.Comment: 14 pages, 11 figures, fixes the wrong names of 4 objects; published on Ap