In this work, mathematical modeling of the motion of charged microdroplets with diameters of 30 and 100 μm under the combined action of electric and gas-dynamic fields is carried out. The structure of the electric field was determined by a system of coaxially located liquid and gas spray capillaries and an annular transport counter electrode. The diameter of the hole in it ranged from 15 to 21 mm; electric potential on capillaries from 2.4 to 5 kV. The pressure excess of the gas at the inlet to the capillary system over the atmosphere ranged from 1 to 6 atm. The numerical integration of the system of Navier–Stokes equations was carried out using the ANSYS Fluent package in an axisymmetric formulation without taking into account the space charge of the droplets.

We propose the design of a compact Mattauch–Herzog ion-optical system featuring a double-focusing static mass spectrometer with a cylindrical electrostatic deflector. This system offers second-order angle focusing and first-order energy focusing along the focal line. The collimating system ensures the optimal vertical acceptance of the mass analyzer and maximum ion transmission within the working mass range. The described ion-optical system serves as a foundation for small-sized mass spectrometers, weighing up to 50 kg, including turbo-molecular and foreline pumps, while maintaining high analytical performance.

A new method of chemical synthesis based on carrying out of chemical reactions in microdroplets is currently being actively developed. Low productivity of microdroplet chemical synthesis is the main obstacle for its practical use. A prototype of a microdroplet chemical reactor operating on the basis of electrospray and allowing a significant increase in the productivity of microdroplet chemical synthesis is described in this paper.

Full-particle massive modeling of physical processes in the Earth’s atmosphere leading to generation of Cherenkov radiation in γ-ray- and proton-induced extensive air showers (EASs), as well as Monte Carlo modeling of photon transport in small-size Cherenkov telescope and signal registration with a camera based on OnSemi MicroFJ type semiconductor photomultiplier (SiPM) detectors have been performed. Calculations have been carried out for primaries with energies in the 0.3–30 TeV range and a Cherenkov telescope with an ≃10 m2 mirror similar to that employed at the TAIGA observatory. It is shown that, even with strict selection criteria ensuring high-quality EAS images, the threshold detection energy of the SiPM-based camera would not exceed 0.8 TeV, which is about twice as low as the detection threshold (≃1.5 TeV) of a small-size TAIGA-IACT telescope camera based on vacuum photomultipliers.

Full-particle modeling of gamma-ray and proton induced extensive air showers (EASs) in the Earth's atmosphere as well as Monte Carlo modeling of photon transport in a small size Cherenkov telescope and signal registration with its camera based on the OnSemi MicroFJ SiPM detectors have been performed. Calculations have been carried out for primaries within the 0.3 - 30 TeV range and a telescope with a 10 m(2) mirror similar to the unit employed at the TAIGA observatory. It has been shown that even with strict selection criteria aimed at high quality EAS images, the threshold detection energy of the SiPM-based camera would not exceed 0.8 TeV - about twice as low as the current threshold of the TAIGA-IACT camera based on vacuum photomultipliers.

This study was devoted to measurements of the UV-range photon detection efficiency (PDE) of OnSemi MicroFJ SiPM detectors use together with custom UV filters and of the transmission coefficient of these filters at 277 nm. The final goal of these measurements was to determine feasibility of the filters for the new detector cluster of the TAIGA-IACT telescope. PicoQuant PLS-270 UV source emitting pulses at 277 nm was calibrated. The obtained dependences of the registered radiation power on the distance between the emission source and the reference detector are well approximated by the inverse square function, hence no significant scattering or absorption influenced the PDE measurements. The dependences of the number of detected photons on the distance between the source and the detector were obtained. These dependencies are also well approximated by the inverse square function. The PDE of SiPM MicroFJ-60035 detector was measured at the level of 10.0 ± 0.7%. The transmission coefficients of the considered set of filters at the wavelength of 277 nm were also obtained. The SL 240-300 filter has a sufficiently high transmission coefficient and it is advisable to use it as a bandpass ultraviolet filter in the new detector cluster of the TAIGA-IACT telescope; the SL 290-590 filter absorbs ultraviolet light quite well and is applicable in the visible range.

The present work is devoted to the study of the possibility of electrospray onto the surface of a liquid in order to accumulate the products of reactions occurring in micro- and nanodroplets of the electrospray torch. The experimental device was made for research purposes. A stable mode of electrospray of a water-ethanol mixture (1:4) onto a liquid electrode (water-ethanol mixture (1:4)), without using sputting gas, was obtained at a spray voltage U of at least 4 kV and a distance between the spray needle and the surface of the liquid R of no more than 15 mm. The spray current increased as the distance between the spray needle and the surface of the liquid electrode decreased and the spray voltage increased. A stable mode of electrospray of the reaction mixture (4 ml of a mixture of acetonitrile and 0.2 % formic acid solution in water (1: 1), 0.5 ml of aniline and 0.5 ml of acetone) onto the surface of the liquid electrode (mixture of 6 ml of acetonitrile and 6 ml of 0.2 % formic acid solution in water or a mixture of 6 ml of acetonitrile and 6 ml of water) with the use of the sputting gas was obtained with the following values of the parameters of the experimental device: the flow rate of the spray solution Qp = = 100 μL / min, the spray voltage U = 3.2 kV, the distance between the surface of the liquid electrode and the spray needle R = 35 mm. The maximum flow rate of the sputting gas was 2 L/min. Unreacted substances and the chemical reactions products of the components of the sprayed reaction mixture accumulated in the liquid electrode when the given values of the parameters of the device were used. This was confirmed by spectrophotometric measurements.

The present paper deals with the study of condensation reaction of aniline with acetone under electrospray ionization (ESI) conditions . An experimental setup is described for conducting reactions under ESI conditions with a possibility of the accumulation of reaction products. The aniline and acetone condensation products were analyzed by gas chromatography–mass spectrometry. Spraying this mixture with high concentration of formic acid, results in the formation of N-phenylformamide, N,N'-diphenylmethaneimidamide, and 1,2-dihydro-2,2,4-trimethylquinoline; the last one is the only product of the reaction of aniline with acetone. Thus, the Schiff base formation reaction radically changes its direction. The results obtained using the proposed experimental setup open up new prospects both for studying chemical reactions in charged microdroplets and for the use of ESI as a preparative method for the synthesis of organic compounds.

О МЕХАНИЗМЕ ФОРМИРОВАНИЯ КАПЕЛЬ В Х-ОБРАЗНОМ МИКРОФЛЮИДНОМ УСТРОЙСТВЕВ работе описаны результаты экспериментального исследования генерирования микроэмульсий в микрофлюидном устройстве собственного производства, оснащенном X-образным смесителем.Представленные карты режимов показали значительное влияние концентрации поверхностно-активных веществ на режим течения в канале и на размер формируемых капель.Получено универсальное уравнение для расчета критических капиллярных чисел, определяющих переход между режимами течения

We have modeled propagation of source signal and noise for a future camera of TAIGA-IACT Cherenkov gamma-ray telescope, which will be based on silicon photomultipliers sensitive in the 240 -- 600 nm range. It has been shown that employment of such detectors instead of traditional vacuum photomultipliers will allow one to decrease the energy threshold by a factor of about 2.5: from ~ 1.5 TeV down to ~ 0.6 TeV. We have also shown that application of a standard ultraviolet filter ZWB3 will decrease the source signal by a factor of 3, while the noise signal from the night sky will be decreased by a factor of 6. In this way the duty cycle of the telescope can be extended (the telescope will be able to operate during moonlit nights and during twilight) and the energy threshold further decreased down to ~ 0.3 TeV. A narrow 260 -- 300 nm filter can be employed to improve gamma-hadron separation of primary cosmic particles in the ~ 25 -- 50 TeV band.

Source and noise signals in a new camera of the TAIGA-IACT Cherenkov γ-ray telescope based on silicon photomultipliers (SiPM) have been simulated. It is shown that application of modern silicon photomultipliers as detecting elements of TAIGA-IACT (instead of the currently used conventional vacuum photomultipliers) will make it possible to reduce the threshold detection energy of cosmic γ quanta by a factor of about 2.5 (from ≃1.5 to ≃0.6 TeV). It is also shown that employment of a standard ZWB3 UV filter mask in the TAIGA-IACT camera would reduce the average signal level by a factor of about 3 and the noise (background) level from the night sky by a factor of about 6, which would allow one to extend the duty cycle of the telescope (in particular, to carry out observations during moonlit nights and twilights) and to additionally reduce the threshold detection energy down to ≃0.3 TeV. The application of a narrower UV filter of 260–300 nm bandwidth can increase the efficiency of determining the primary particle type (γ-hadron separation) in the energy range from ~25 up to ~50 TeV.

Methane seasonal variation observable by MSL mission and possible variations of atmospheric mass on timescale (105-106 years) are among the most intriguing problems in Mars exploration. These variations are connected with hypothetical biosphere activity in the subsurface Martian soil and existence of liquid water on the Martian surface within modern era. Stability of liquid water on surface request higher atmospheric pressure in comparing to modern value. CO2 cannot loss with known mechanisms of atmospheric escape. Therefore, the main part of necessary CO2 must be buried in upper layers of the Martian soil. Local and seasonal time variable sources and fast methane destruction are needed to explain high seasonal variations of methane concentration in air at the Martian surface. Gas reservoirs, containing biogenic or abiogenic methane could be possible seasonal sources of methane as well. In this work we experimental study stability of the gas reservoirs covered of mixture of regolith and water ice with perchlorates. Thickness of covered regolith layer was about 10mm. In experimental runs we increased a temperature of gas traps and monitored a possible diffusion of gases through the isolated layer with mass spectrometer. The gas traps stay stable at gas pressure up to 1 bar. We did not discover any diffusion process before mechanical destruction of reservoirs at gas pressure over 1 bar. In this work we show that the big subsurface gas reservoirs can exist for a long time before cracking due to slow process of the water ice sublimation by climate and seasonal variation of subsurface temperature.

Static mass spectrometer for detecting pathologies in the human organism from to the composition of exhaled air is described in this paper. The instrument is equipped with the capillary and membrane sample intake systems for dynamic investigations of a number of components in the exhaled mixture as well as for determining trace amounts of specific volatile biomarkers accompanying diseases of the respiratory system, blood circulation system, interstitial tract, and endocrine system. Tests of the mass spectrometer with the membrane sample inlet system have shown for one of the markers that the monitoring of acetone vapor in air during the respiratory process can be carried out at a level of ∼1 ppm. Mass spectrometric detection of a number of other markers with a higher (up to two orders of magnitude) penetrability through the membrane as compared to acetone becomes possible at the ppb level. The presented static mass spectrometer was tested for the possibility of working with a linear Ion CCD matrix designed to directly register ions in a wide energy range. The experimental results prove that the selected scheme of the mass spectrometer can be used in combination with both the IonCCD detector and the microchannel plate – IonCCD detector without significantly deteriorating the main performance characteristics of the instrument.

Поступило в Редакцию 28 ноября 2017 г

Absorption spectra of pigments derived from the plants that were illuminated by light with different spectral composition during their growth are presented. The role of the spectrum of LED lighting in the life of plants has been estimated, and its influence on pigment absorption has been noted. It has been recommended to use a full range of lighting in the range of 400–700 nm with the domination of the red component when growing oats in protected ground. It has been found that the recording of absorption spectra of pigments allows the monitoring of the influence of lighting on the processes of plant growth and development. It has been assumed that the use of sources with a controlled spectrum in a greenhouse will allow directed influence on the nature of biochemical reactions occurring in plants during their development: photosynthesis and photomorphogenesis.

This paper describes an online realtime data acquisition system.The design utilizes ARM singleboard computers that bring very low power requirements, portability and lightweightness.We have implemented a unified approach to acquire, transfer and store the measurements.The approach takes advantages of SeedLink protocol to establish online realtime data flows between the components of the system.Communication over IPv4 rely on secure virtual private networks.The system features remote management of data logger and all connected devices.For purposes of testing and technology showcase we've implemented support for a range of variometer-type magnetometers.

Measurements of energy transformation and dissipation in mitochondria by the calorimetric method were carried out in the second half of the last century.However, to date no specialized calorimeter has been developed for this purpose.Selection of compounds providing uncoupleted mitochondrial respiration without damaging the respiratory chain components, for use in pharmaceutical compositions of drugs, development of new neuroprotectors, nefroprotectors require precise measurements of heat release by different mitochondrial uncouplers of oxidative phosphorylation.A capillary differential nanocalorimeter for studying energy transformation and dissipation in the mitochondria has been created in the IBI RAS .The instrument meets the above requirements.The principal advantage of the nanocalorimeter is that it has thermal bridges for the thermostatingthe mitochondria injection.In the thermal bridges mitochondria acquire the desired temperature for a few seconds.Mitochondria are introduced uniformly along the entire length of the calorimeter chamber by means of a dispensing needle.This provides mixing of mitochondria with the sample without great energy consumption and thermal noise.Precision measurements of thermal power of the processes of transformation and dissipation of energy in the mitochondria are carried out at an absolute error less than 50 nW.