Insecticidal contact toxicity of several essential oils against stored product pests: Poster

Results of laboratory bioassays in Petri dishes on evaluation of contact toxicity of Illicium verum, Artemisia absinthium and Abies sibirica essential oils (EOs) against larvae of khapra beetle, Trogoderma granarium Ev., adults of grain weevil, Sitophilus granarius L., and rice weevil, Sitophilus oryzae L., and confused flour beetle, Tribolium confusum Duv., and larvae and adults of the lesser mealworm, Tenebrio molitor L., are presented. EOs commercial samples from retail pharmacy were tested at doses 0.01, 0.25, 0.50, 0.75 and 1.00 µl/cm2. A treated Petri dish surface treted with acetone was used as a control. The experiment was carried out in triplicate. Mortality of insects was assessed after 1, 3, 6 and 24 hours post exposure. After exposure insects were placed into untreated Petri dishes for 3 days. The main components of the A. absinthium EOs are thujil alcohol (19.65%), phellandrene (16.71%), borneol (12.1%) and thujone (11.55%) was found. The major component of I. verum EOs was anethole (98.64%). Isobornyl acetate (57.25%), a-pinene (13.55%) and limonene (10.62%) were found as the main components of A. sibirica EOs. S. oryzae and S. granarius were most sensitive to each EO. I. verum EOs was the most effective and caused 100% mortality of each insect at the dose 0.25 µl/cm2.Results of laboratory bioassays in Petri dishes on evaluation of contact toxicity of Illicium verum, Artemisia absinthium and Abies sibirica essential oils (EOs) against larvae of khapra beetle, Trogoderma granarium Ev., adults of grain weevil, Sitophilus granarius L., and rice weevil, Sitophilus oryzae L., and confused flour beetle, Tribolium confusum Duv., and larvae and adults of the lesser mealworm, Tenebrio molitor L., are presented. EOs commercial samples from retail pharmacy were tested at doses 0.01, 0.25, 0.50, 0.75 and 1.00 µl/cm2. A treated Petri dish surface treted with acetone was used as a control. The experiment was carried out in triplicate. Mortality of insects was assessed after 1, 3, 6 and 24 hours post exposure. After exposure insects were placed into untreated Petri dishes for 3 days. The main components of the A. absinthium EOs are thujil alcohol (19.65%), phellandrene (16.71%), borneol (12.1%) and thujone (11.55%) was found. The major component of I. verum EOs was anethole (98.64%). Isobornyl acetate (57.25%), a-pinene (13.55%) and limonene (10.62%) were found as the main components of A. sibirica EOs. S. oryzae and S. granarius were most sensitive to each EO. I. verum EOs was the most effective and caused 100% mortality of each insect at the dose 0.25 µl/cm2

Bimeron nanoconfined design

We report on the stabilization of the topological bimeron excitations in confined geometries. The Monte Carlo simulations for a ferromagnet with a strong Dzyaloshinskii-Moriya interaction revealed the formation of a mixed skyrmion-bimeron phase. The vacancy grid created in the spin lattice drastically changes the picture of the topological excitations and allows one to choose between the formation of a pure bimeron and skyrmion lattice. We found that the rhombic plaquette provides a natural environment for stabilization of the bimeron excitations. Such a rhombic geometry can protect the topological state even in the absence of the magnetic field.Comment: 5 pages, 7 figure

Profile approach for recognition of three-dimensional magnetic structures

We propose an approach for low-dimensional visualisation and classification of complex topological magnetic structures formed in magnetic materials. Within the approach one converts a three-dimensional magnetic configuration to a vector containing the only components of the spins that are parallel to the z axis. The next crucial step is to sort the vector elements in ascending or descending order. Having visualized profiles of the sorted spin vectors one can distinguish configurations belonging to different phases even with the same total magnetization. For instance, spin spiral and paramagnetic states with zero total magnetic moment can be easily identified. Being combined with a simplest neural network our profile approach provides a very accurate phase classification for three-dimensional magnets characterized by complex multispiral states even in the critical areas close to phases transitions. By the example of the skyrmionic configurations we show that profile approach can be used to separate the states belonging to the same phase

Study of the resonance α+13C interaction at low energies: Optimization of parameters of the beam shape

About half of all elements heavier than iron are produced in a stellar environment through the s process, which involves a series of subsequent neutron captures and α decays. The reaction 13C(α,n)16O is considered to be the main source of neutrons for the s process at low temperatures in low mass stars in the asymptotic giant branch (AGB). In order to understand better creation of such elements we need to imrove the understanding of creation of such elements, that is to obtain the excitation functions of the 13C (α, α)17O elastic scattering at the initial beam energy 13C from 1.7Mev/A till energies close to zero by using the Thick Target Inverse Kinematics method (TTIK) [1]. The experiment will be conducted in Astana, KZ by using a new heavy ion accelerator DC-60 that provides ion beam with the energy 1.75 MeV/nucleon [1]. To improve the results and reduce errors, the profiling of the beam within the experimental camera is required. In this article, the detailed preparations for this measurement are described

Random Number Hardware Generator Using Geiger-Mode Avalanche Photo Detector

The main problems with existing hardware random number generators today are either low speed and/or prohibitively high cost. The physical concept and test results of sample data of the high-speed hardware true random number generator design based Hamamatsu MPPC photo sensor are shown. Main features of this concept are the high speed of the true random numbers generation (tens of Mbt/s), miniature size and estimated lower production cost. This allows the use of such a device not only in large companies and government offices but for the end-user data cryptography, in classrooms, in scientific Monte-Carlo simulations, computer games and any other place where large number of true random numbers is required. The physics of the operations principle of using a Geiger-mode avalanche photo detector is briefly discussed and the high quality of the data collected is demonstrate

Random Number Hardware Generator Using Geiger-Mode Avalanche Photo Detector

The main problems with existing hardware random number generators today are either low speed and/or prohibitively high cost. The physical concept and test results of sample data of the high-speed hardware true random number generator design based Hamamatsu MPPC photo sensor are shown. Main features of this concept are the high speed of the true random numbers generation (tens of Mbt/s), miniature size and estimated lower production cost. This allows the use of such a device not only in large companies and government offices but for the end-user data cryptography, in classrooms, in scientific Monte-Carlo simulations, computer games and any other place where large number of true random numbers is required. The physics of the operations principle of using a Geiger-mode avalanche photo detector is briefly discussed and the high quality of the data collected is demonstrated

Study of the resonance α+13C interaction at low energies: Optimization of parameters of the beam shape

About half of all elements heavier than iron are produced in a stellar environment through the s process, which involves a series of subsequent neutron captures and α decays. The reaction 13C(α,n)16O is considered to be the main source of neutrons for the s process at low temperatures in low mass stars in the asymptotic giant branch (AGB). In order to understand better creation of such elements we need to imrove the understanding of creation of such elements, that is to obtain the excitation functions of the 13C (α, α)17O elastic scattering at the initial beam energy 13C from 1.7Mev/A till energies close to zero by using the Thick Target Inverse Kinematics method (TTIK) [1]. The experiment will be conducted in Astana, KZ by using a new heavy ion accelerator DC-60 that provides ion beam with the energy 1.75 MeV/nucleon [1]. To improve the results and reduce errors, the profiling of the beam within the experimental camera is required. In this article, the detailed preparations for this measurement are described

Optimization of the Liquid Scintillator Composition

Nowadays, many particle detectors use liquid scintillator (LS) as a detection medium. In particular, Water-based Liquid Scintillator (WbLS) that is a new material currently under development. It is based on the idea of dissolving the organic scintillator in water using special surfactants. This material strives to achieve the novel detection techniques by combining the Cherenkov and scintillation light, as well as the total cost reduction compared to pure liquid scintillator. An important part of either the pure LS or WbLS production is to choose the right fluor and shifter and their concentrations. The choice affects the spectral distribution of the light output and the detection efficiency as each photodetector has its own spectral sensitivity region. This work presents the results of the study on the pseudocumen (PC) based LS with the PPO and POPOP/MSB as a fluor and shifters of choice. Both the total light yield and the spectral differences in the outputs with different amounts of components are shown. This study can be applied to plastic scintillators as well. 38t