23 research outputs found
POSSIBILITIES FOR INCREASING THE YIELDS AFTER PRE-SOWING ELECTRIC TREATMENT OF WHEAT AND MAIZE SEEDS
Following many years of research, it has been determined that for the environmentally friendly stimulation of the growth of plants and increase of their yields, it is necessary to apply pre-sowing electromagnetic treatment to the seeds of these plants.A study has been carried out of the impact of the pre-sowing electromagnetic treatment of the seeds of different Bulgarian wheat varieties and of maize hybrids provided by Bulgarian producers and by the companies Pioneer-USA and the French Maisadour Semences.At certain values of the controllable factors of the pre-sowing treatment, the following results have been achieved: an increase of (9...20)% in wheat yields as compared to the control batch, and an increase in the length of the maize ears, a higher number of leaves and a higher number of kernel rows in an ear, a higher number of kernels in a row, and yields increased by (5...21)% as compared to the control batch.Following many years of research, it has been determined that for the environmentally friendly stimulation of the growth of plants and increase of their yields, it is necessary to apply pre-sowing electromagnetic treatment to the seeds of these plants.A study has been carried out of the impact of the pre-sowing electromagnetic treatment of the seeds of different Bulgarian wheat varieties and of maize hybrids provided by Bulgarian producers and by the companies Pioneer-USA and the French Maisadour Semences.At certain values of the controllable factors of the pre-sowing treatment, the following results have been achieved: an increase of (9...20)% in wheat yields as compared to the control batch, and an increase in the length of the maize ears, a higher number of leaves and a higher number of kernel rows in an ear, a higher number of kernels in a row, and yields increased by (5...21)% as compared to the control batch
Pulsed electromagnetic field - a cultivation practice used to increase soybean seed germination and yield
The aim of the research was to test the effect of pulsed electromagnetic field (PEMF) on soybean seed germination and yield depending on specific field conditions, years of study, exposure duration and frequency. Field trial was conducted on an experimental field of Institute of Field and Vegetable Crops in Novi Sad, Serbia in 2010-2013. Seeds of the soybean (Glycine hispida (Moench)) medium-early cultivar. Valjevka 'were exposed to the PEMF therapy using the impulse generator and strip. Low-frequency (16, 24, 30 and 72 Hz) PEMF was used in the duration of 0, 30, 60 and 90 minutes. Research results indicate that this method can increase seed germination up to 8.00% and yield by 960.5 kg, or 21% in field conditions, which is a significant increase and a solid basis to introduce this practice, primarily in organic production with a very limited use of seed treatment preparations. However, the practice can have an inhibitory effect under an unfavourable combination of exposure duration and frequency. The obtained data were processed using the analysis of variance of three-factorial trials considering all years of study. Due to different meteorological conditions in the study years, analysis of variance was conducted for each year of study and correlations between the tested traits were examined
VPA: Computer program for the computation of the phase shift in atom–atom potential scattering using the Variable Phase Approach
A computer code for the computation of the phase shift in atom–atom and electron–atom potential scattering is presented. The phase shift is the central quantity required for the calculation of all types of scattering cross sections. The program uses the Variable Phase Approach (VPA). This is the only exact method for the direct calculation of the scattering phase shift. All other methods are based on examining the large distance behavior of the exact solution of the Schrödinger equation. Such methods yield the phase shift only modulo π. The absolute value of the phase shift and its variation with scattering energy is, however, needed for a full understanding of the scattering process, such as for instance in the study of shape resonances and Glory oscillations. The VPA has been sparingly used owing to the instability of the underlying equations and the consequent difficulty of writing computer code to solve them. We present a computer code for the efficient implementation of the VPA method for atom–atom scattering problems over a wide range of scattering energies. The code works for potentials which are singular and for those that are non-singular at the origin. An example of the implementation of the code is given for both an interaction potential with an attractive well and for a purely repulsive potential
VPA: Computer program for the computation of the phase shift in atom–atom potential scattering using the Variable Phase Approach
A computer code for the computation of the phase shift in atom–atom and electron–atom potential scattering is presented. The phase shift is the central quantity required for the calculation of all types of scattering cross sections. The program uses the Variable Phase Approach (VPA). This is the only exact method for the direct calculation of the scattering phase shift. All other methods are based on examining the large distance behavior of the exact solution of the Schrödinger equation. Such methods yield the phase shift only modulo π. The absolute value of the phase shift and its variation with scattering energy is, however, needed for a full understanding of the scattering process, such as for instance in the study of shape resonances and Glory oscillations. The VPA has been sparingly used owing to the instability of the underlying equations and the consequent difficulty of writing computer code to solve them. We present a computer code for the efficient implementation of the VPA method for atom–atom scattering problems over a wide range of scattering energies. The code works for potentials which are singular and for those that are non-singular at the origin. An example of the implementation of the code is given for both an interaction potential with an attractive well and for a purely repulsive potential
Collision Cross Sections for O + Ar<sup>+</sup> Collisions in the Energy Range 0.03–500 eV
The
interatomic potentials of the a<sup>2</sup>Î and b<sup>2</sup>Î states of the OAr<sup>+</sup> molecule are calculated
using the relativistic complete-active space Hartree–Fock method
followed by a multireference configuration interaction calculation
with an aug-cc-pwCVNZ-DK basis sets where N is 4 and 5. The calculations
were followed by an extrapolation to the complete basis set limit.
An avoided crossing between the two potential energy curves is found
at an internuclear separation of 5.75 bohr (3.04 Ã…). As the transition
probability between the curves is negligible in the relative collision
energy range 0.03–500 eV of interest here, collisions on the
lower adiabatic a<sup>2</sup>Î potential may be treated without
reference to the upper state. For low energies and orbital angular
momentum quantum numbers, the one-dimensional radial Schrödinger
equation is solved numerically using a Numerov algorithm method to
determine the phase shift. The semiclassical JWKB approximation was
employed for relative energies greater than 5 eV and orbital angular
quantum numbers higher than 500. Differential, integral, transport
(diffusion), and viscosity cross sections for elastic collisions of
oxygen atoms with argon ions are calculated for the first time for
the range of relative collision energies studied. The calculated cross
sections are expected to be of utility in the fields of nanotechnology
and arc welding. The combination of an Ar<sup>+</sup>(<sup>2</sup>P) ion and a OÂ(<sup>3</sup>P) atom gives rise to a total of 12 different
molecular electronic states that are all coupled by spin–orbit
interactions. Potential energy curves for all 12 states are computed
at the complete active space self-consistent field (CASSCF) level
and scattering calculations performed. The results are compared with
those obtained using just the lowest potential energy curve
Collision Cross Sections for O + Ar<sup>+</sup> Collisions in the Energy Range 0.03–500 eV
The
interatomic potentials of the a<sup>2</sup>Î and b<sup>2</sup>Î states of the OAr<sup>+</sup> molecule are calculated
using the relativistic complete-active space Hartree–Fock method
followed by a multireference configuration interaction calculation
with an aug-cc-pwCVNZ-DK basis sets where N is 4 and 5. The calculations
were followed by an extrapolation to the complete basis set limit.
An avoided crossing between the two potential energy curves is found
at an internuclear separation of 5.75 bohr (3.04 Ã…). As the transition
probability between the curves is negligible in the relative collision
energy range 0.03–500 eV of interest here, collisions on the
lower adiabatic a<sup>2</sup>Î potential may be treated without
reference to the upper state. For low energies and orbital angular
momentum quantum numbers, the one-dimensional radial Schrödinger
equation is solved numerically using a Numerov algorithm method to
determine the phase shift. The semiclassical JWKB approximation was
employed for relative energies greater than 5 eV and orbital angular
quantum numbers higher than 500. Differential, integral, transport
(diffusion), and viscosity cross sections for elastic collisions of
oxygen atoms with argon ions are calculated for the first time for
the range of relative collision energies studied. The calculated cross
sections are expected to be of utility in the fields of nanotechnology
and arc welding. The combination of an Ar<sup>+</sup>(<sup>2</sup>P) ion and a OÂ(<sup>3</sup>P) atom gives rise to a total of 12 different
molecular electronic states that are all coupled by spin–orbit
interactions. Potential energy curves for all 12 states are computed
at the complete active space self-consistent field (CASSCF) level
and scattering calculations performed. The results are compared with
those obtained using just the lowest potential energy curve
Fluorine atoms interaction with the nanoporous materials: experiment and DFT simulation
Fluorine atoms interactions with organosilicate glass (OSG)-based low-κ dielectric films are experimentally and theoretically studied. One-dimensional 1-D Monte Carlo & gas-surface kinetics (MC&GSK) model and density functional theory (DFT) simulations used for the development of the multi-step mechanism of OSG films damage and etching are further verified on FTIR spectroscopy data. DFT method is applied to calculate vibrational mode frequencies and their shifts under F atoms flux. In the frame of 1-D model, evolutions of the SiCH3 and appeared SiCHxFy surface groups distributions inside the porous films are calculated as a function of F atoms dose. F atoms quasi-chemisorption on surface SiOx groups accompanied by fourth-coordinated Si atoms transition to pentavalent Si states is related with the experimentally observed fast fluorination stage and vibrational frequency shifts. In addition, quasi-chemisorbed F atoms induce the weakening of the adjacent Si–O bonds in OxSiFy surface complexes promoting breaks of these Si–O bonds under further F atoms attacks. Quasi-chemisorbed F atoms could be also responsible for F atoms recombination on SiOx surfaces
Experimental and DFT study of nitrogen atoms interactions with SiOCH low-
Damage of porous organosilicate glass (OSG) films with low dielectric constants (low-κ films) in plasma processing is a critical problem for modern microelectronics. For this problem, understanding and revealing of basic reaction steps for radicals etching and damage are of importance. Previously we have studied experimentally and theoretically the etching and damage of low-κ dielectric films under oxygen and fluorine atoms. Here the effects of N atoms on OSG films are studied experimentally by Fourier Transform InfraRed (FTIR) spectroscopy method and theoretically by density functional theory (DFT) method. Experimental FTIR spectra are compared with calculated vibrational spectra to reveal the relevant surface SiCHxNy groups which could be produced in multi-step reactive collisions of N atoms in ground and lower metastable states with OSG low-κ dielectric films