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The objectives of the study have been to determine the effects of winter precipitation, NO3-N distribution in the soil profile and their interaction on corn yield in different fertilization systems. Corn yield varied across fertilization systems and winter rainfall in the investigated years (2001–2004). Significantly higher yields were found in variants with manure application in diculture (DC-M-NPK — 12.11 t ha-1) and in monoculture (MC-M-NPK — 9.25 t ha-1). Path coefficients showed that the highest direct positive effects on corn yields were exhibited by NO3-N amounts at soil depths 30–60 cm and 60–90 cm (p = 0.4336** and p = 0.2346**, respectively). Winter precipitation had a direct negative effect on the yield performance (p = -0.1159), however, the downward movement of NO3-N from topsoil (0–30 cm) to deeper soil layers (30–60 and 60–90 cm), whose N levels were directly positively correlated with yield, made the indirect effect of winter precipitation on yield positive.

We present experimental and theoretical differential cross sections for elastic electron scattering from xenon. Two independent measurements were carried out at (1) Chungnam National University for incident electron energies of 10, 20, 30, 50 and 100 eV and scattering angles from 10° up to 180° and (2) the Institute of Physics in Belgrade for incident electron energies of 20, 30 and 50 eV and scattering angles from 10° up to 150°. While these latter measurements do not cover the full angular range up to 180°, they still extend somewhat higher in scattering angle than previous measurements. It would appear that the theoretical treatment of intermediate energy elastic scattering from xenon is sensitive to the inclusion of absorption effects, particularly at backward scattering angles. This observation plus the previous results for the case of krypton indicates that the role of absorption is generally quite important for the rare gases.

Differential cross sections (DCS) for electron-impact excitation of the 3s3p 1P1state in magnesium at incident electron energies E0= 10, 15, 20, 40, 60, 80 and 100 eV have been measured and corresponding calculations carried out. Scattered-electron intensities were measured over a wide range of scattering angles (10°-150°) and normalized to the DCSs at 10° experimentally obtained by Filipovic et al(2006 Int. J. Mass Spectrom. 25166). Corresponding calculations have been conducted in the relativistic distorted-wave approximation. Integrated (integral, momentum transfer and viscosity) cross sections are determined by numerical integration of our DCSs. The results are analysed and compared with previous experimental data and theoretical calculations.

A crossed-beam experimental set-up, which allows independent measurement of differential electron-atom (molecule) elastic scattering cross section as a function of both scattering angle and incident electron energy, is described. The experimental system utilizes an electron gun and a double cylindrical mirror analyser, which are described in detail. A procedure for obtaining constant scattering geometry, transmission function and detection efficiency, in a wide range of the incident electron energies (40-250 eV), was tested experimentally and by means of electron trace simulations. The present experimental procedure allows determination of a two-dimensional relative differential cross-section surface, which can be calibrated to the absolute scale via normalization to a single point.

Differential cross sections (DCSs) for electron-impact excitation of the 4f146s6p3P1(2.231 eV) state of ytterbium have been determined experimentally at incident electron energies, E0= 10, 20 and 40 eV, and scattering angles (?) from 2° to 150° (at 10 eV from 10°). Also, DCSs for the 4f145d6s 1D2(3.432 eV) and 4f135d6s2(7/2, 5/2)1(3.578 eV) states at E0= 10 and 20 eV, and the 4f146s7p 1P1(5.029 eV) state at 20 and 40 eV have been measured. These measurements were performed at ? between 10° and 150° for the 4f145d6s 1D2and 4f135d6s2(7/2, 5/2)1states, and between 2° and 150° for the 4f146s7p 1P1state. The inelastic-to-reference inelastic (the 4f146s6p 1P1resonance state) intensity ratios were obtained from energy-loss spectra recorded with overall energy resolution of 65 meV (FWHM) and angular resolution of 1.5°. Using these ratios and DCSs for the reference state (Predojevic et al2005 J. Phys. B: At. Mol. Opt. Phys.381329) the absolute inelastic DCSs were determined. In this way the obtained DCSs were extrapolated to 0° and 180° and numerically integrated to yield integral, momentum transfer and viscosity cross sections. Our results are compared with available calculated values and experimental data.

The experimental and theoretical studies of elastic electron scattering by calcium atom have been made. The experimental investigation was carried out using a crossed electron-atom beam technique. The measurements were performed at electron-impact energies (E0) of 10, 20, 40, 60 and 100 eV and for a range of scattering angles (?) from 10° up to 150°. The absolute differential cross sections (DCSs) have been obtained from the elastic-to-inelastic (the resonant 41P0state) intensity ratio at ? = 10° at each E0. Calculations have been performed in the optical potential approximation for the same E0and ? between 0° and 180°. Results for DCSs and integrated (integral, momentum transfer and viscosity) cross sections are presented and compared with those predicted by existing calculations.

Elastic scattering of electrons by krypton atom was investigated both experimentally and theoretically. Differential cross sections (DCSs) were measured at fixed incident energies from 20 eV to 80 eV as a function of scattering angle (10°-150°). From 100 eV, DCSs were measured as a function of both incident electron energy (100-260 eV) and scattering angle (30°-110°), in small steps around minima. The energy dependence of the angular positions of DCS minima was determined. Theoretical results were obtained in terms of a model of phenomenological complex potential with allowance for spin-orbit interaction. Two data sets were calculated, with and without an absorption potential, and compared to experimental results. The improvements and deteriorations in agreement with measurements upon inclusion of absorption effects are discussed.

Differential cross sections (DCSs) for electron-impact excitation of the 4f146s6p 1P1resonance state of ytterbium were measured at 10, 20, 40, 60 and 80 eV incident electron energies (E0) and scattering angles (?) between 2° and 150°. The absolute DCS scale for the 1P1state was determined through normalization of its relative DCSs to the optical oscillator strength using the forward scattering function method. DCSs for elastic electron scattering by ytterbium were measured at the same energies for ? between 10° and 150°. Elastic-to-inelastic intensity ratios were obtained from energy-loss spectra recorded with overall energy resolution of 65 meV (FWHM) and angular resolution of 1.5°. Both inelastic and elastic DCSs were extrapolated to 0° and 180° and numerically integrated to yield integral, momentum transfer and viscosity cross sections. Our results are compared with scarce experimental and theoretical data.

The position of the critical minimum in elastic electron-krypton scattering at intermediate electron energies was investigated. Differential cross sections (DCSs) were measured as a function of both incident electron energy (100-260 eV) and scattering angle (30-110°), in small steps around the critical minimum. The energy dependence of the angular positions of DCS minima were determined. Also, the positions of minima in energy-dependent DCSs were obtained at several fixed scattering angles close to the critical value. The position of the critical minimum was determined to be at 187.9 ± 0.5 eV and 83.0° ± 0.2°. However, the strong dependence of critical energy on small changes of critical angle was found. The obtained results are compared with the most recent theoretical calculations.

The application of pressure as a technique for obtaining dense and mechanically strengthen materials has been investigated from the structural aspect by the use of X‐Ray Powder Diffraction (XRPD) and Scanning Tunneling Microscopy (STM).

Zinc‐oxide powder was tribophysically activated in a high‐energy vibro mill in a continual regime in air for 3, 30 and 300 minutes with the purpose of modifying the powders physico‐chemical properties. By analyzing of data obtained by X‐ray powder diffraction, electron diffraction and transmission electron microscopy, the values of distances between corresponding crystallographic planes, average domain sizes of coherent scattering, i.e. crystallites, width of diffraction lines due to the existence of microstrains, and microstrain values, minimal dislocation densities, dislocation density due to microstrain and real dislocation density, and also average distances between dislocations were determined. The dependence of these values on the activation time was established, which enabled analysis of the evolution of the defect structure of zinc‐oxide powders during tribophysical activation by grinding in the described regime.

Tribophysical (mechanical) activation is used as a method for modification of physico‐chemical properties of dispersed systems such as polycrystalline mixture of ZnO and Cr2O3powders, obtained by conventional ceramic powder processing wet technique. Conventional mixtures were tribophysically activated by grinding in a vibro‐mill with a continual regime in air. Conventional mixture and tribophysically activated mixtures, with activation times of 40 and 80 minutes, were thermally treated in non‐isothermal and isothermal conditions. Solid‐state reactions in non‐isothermal conditions were examined by X‐ray diffraction, differential thermal analysis and dilatometric measurements. The influences of tribophysical activation on solid‐state reaction between ZnO and Cr2O3, during thermal treatment in isothermal conditions were investigated by X‐ray diffraction line broadening theory. As a Fourier method for the pure physical line profile analysis a double‐Voigt method is used. Mechanism of mass transport during solid‐state reaction in ZnO‐Cr2O3system is proposed.