Search

The aim of the research is to establish the influence of watering on the phenological and biological features of winter wheat pests development, in particular Sunn pests. Trials were conducted on winter wheat crops under sprinkler irrigation in 2015-2020 in conditions of the Central Forest-Steppe of Ukraine. The size of the experimental plots in the field experiments was 50 m2 (10.4x4.8 m) at the 4 times replication. The allocation of plots was randomized. The average numbers of Sunn pest nymphs in 2015-2020 were 0.7-2.7 exemplars/m² on non-irrigated winter wheat crops and 0.8-3.8 exemplars/m² on irrigated. The share of the factor “presence of irrigation” that impacts on the number of Sunn pests reaches 80.2%. The sums of degree-days necessary for the beginning of different development stages of this phytophagous were calculated. The stage of the revival of Sunn pest nymphs began in mid-May – the first decade of June, which coincided with the phases of development of winter wheat: the end of flowering – soft dough ripening of the grain. The sum of degree-days required for the beginning of this stage was 177.8-233.8°C without irrigation, while in sprinkler irrigation conditions – 275.5-349.1°C. For the beginning of the transformation of the fifth instar nymphs into adults, the required sum of degree-days was 410.5-481.5°C on the non-irrigated crops and 545.7-630.4°C – under conditions of irrigation. Clarifying the sum of degree-days required for different stages of Sunn pest development will allow for predicting the terms of protective measures against this pest in the field conditions under irrigation.

The analysis of the presented works shows that mathematical modeling of austenite decomposition during heat treatment is possible using both ТТТ and ССT diagrams. Тhe effect of the stress-strain state arising in the process of heat treatment of parts on the kinetics of structural transformations is usually not taken into account. The experimental data accumulated to date do not reliably describe the effect of the stress state on structural transitions during the heat treatment of steels. A simple theoretical expression is proposed for calculating the amount of martensite formed as a function of the stress in the γ-phase. To reliably predict the structural state of steels during hot deformation and heat treatment, it is necessary to conduct a comprehensive study related to the experimental study of the effect of stresses on the transformations of all types and the creation of an adequate mathematical model of austenite decomposition based on the experimental data obtained, taking into account this effect.

Objective: To study the peculiarities of the migration of spiromesifen into groundwater and surface water and to predict the risks to human health when using such water for drinking purposes. Methodology: Field experiments to study the dynamics of residual amounts of spiromesifen, its stability and behavior in the soil after fan spraying of apple orchard and vineyard were conducted in different soil and climatic conditions: Steppe, Forest-Steppe, Polissya. Koc, GUS and LEACHmod were used to assess the migration capacity of the insecticide. To predict the risk, we used the integrated hazard vector of groundwater pollution (R) and an integral index of hazard of pesticide contaminated water consumption (IIHPCWC). Results: The calculated value of GUS (-0.92) and leaching index (3.3 × 10-5) allow to pertain spiromesifen to a low level of risk of leaching into groundwater – hazard class 3. It was established that spiromesifen by persistency in soil in soil and climatic conditions of Steppe, Forest-Steppe, Polissya belongs to low-stability pesticides, and characterized by low mobility in soil. Conclusion: It was shown that spiromesifen is a moderately hazardous substance for humans due to groundwater contamination (class 3) and low-risk (class 4) due to surface water contamination by the integral index of hazard of pesticide contaminated water consumption.

The photonic time-stretch technique allows electric field pulse shapes to be recorded with picosecond resolution, at megahertz acquisition rates. Using this strategy, we could directly record spatial patterns that spontaneously appear in relativistic electron bunches, and follow their dynamical evolution over time. We present recent results obtained using two strategies. At SOLEIL, we present the shapes of the THz pulses which are emitted by the structures, and detected far from the emission point, at the end of a beamline. At ANKA, we present how it has been possible to monitor directly the electron bunch near-field. These new types of single-shot recordings allow direct and stringent tests to be performed on electron bunch dynamical models in synchrotron radiation facilities.

Photonic time-stretch enables to record electric field pulse shapes with picosecond resolution, at megahertz acquisition rates. Using this strategy, we could record the complex spatiotemporal evolution of relativistic electron bunches circulating in storage ring accelerators. We tested two complementary approaches. At SOLEIL, we monitored the THz pulses of coherent synchrotron that are emitted by the electrons. At ANKA, we monitored directly the electron bunch near-field.

Longitudinal diagnostics of the electron bunch shapes play a crucial role in the operation of linac-based light sources. Electro-optical techniques allow us to measure the longitudinal electron bunch profiles non-destructively on a shot-by-shot basis. Here we present results from measurements of electron bunches with a length of 200-900 fs rms at the Swiss FEL Injector Test Facility. All the measurements were done using an Yb-doped fibre laser system (with a central wavelength of a 1050 nm) and a GaP crystal. The technique of electro-optical spectral decoding (EOSD) was applied and showed great capabilities to measure bunch shapes down to around 370 fs rms. Measurements were performed for different electron energies to study the expected distortions of the measured bunch profile due to the energy-dependent widening of the electric field, which plays a role for low beam energies below and around 40 MeV. The studies provide valuable input for the design of the EOSD monitors for the compact linear accelerator FLUTE that is currently under commissioning at the Karslruhe Institute of Technology (KIT).