Search

Introduction. Quantum well infrared photodetectors (QWIP) are characterized by a wide application range. A large market demand for such photodetectors determines the importance of elucidating the principle of their operation.Aim. To carry out a research study into the influence of the AlGaAs potential barrier surrounding GaAs quantum wells on the QWIP operating bias voltage in the long-wavelength region of the spectrum (8…10 μm).Materials and methods. QWIP experimental samples were manufactured based on the GaAs/AlGaAs semiconductor material system using molecular beam epitaxy. The photosensitive (active) region of the structures contained 50 GaAs quantum wells with a thickness of 50 Å thick separated by AlGaAs barriers. Quantum wells were doped in situ with silicon as a donor impurity. The wavelength of the maximum spectral sensitivity of all samples ranged within 8…9 μm. The barrier width was the variable parameter. After passing the planar modification process route, the current–voltage characteristics were measured in all structures.Results. Reduction in the barrier thickness is capable of shifting the peak of photosensitivity towards the region of lower bias voltages with a slight increase in the dark current values.Conclusion. The study of the influence of the applied bias voltage presents both scientific and practical interest. On the one hand, the results improve the current understanding of the behavior of the dark current in QWIP. On the other, they provide the possibility of managing the maximum current sensitivity, shifting it towards the region of the required operating voltages of the multiplexers.

The paper investigates the photovoltaic properties of the silicon n+-p-p+-structures and photodiodes made on their basis. It was found that boron diffusion to the reverse side of the substrate, in addition to creating an ohmic contact, generates generation-recombination centers, which allows to reduce the dark current of photodiodes and increase their responsivity. It was also found that chemical dynamic polishing of the back side of the substrates before boron diffusion allows to eliminate a significant number of defects and improve the final parameters of the products. In samples without a p+-layer and samples not polished from the back side, a breakdown of the p-n junction is observed on the back side, which is caused by the expansion of the space charge region to the entire thickness of the substrate and the achievement of a defective back side of the crystal.

In dairy cows, acids of different compositions represent the typical composition of fatty acids, about 70% of them are saturated fatty acids (SFA), 25% monounsaturated fatty acids (MUFA) and 5% polyunsaturated fatty acids (PUFA), which significantly differs from the ideal profile of fatty acids for human health. The analysis of methyl esters of fatty acids was carried out using a Shimadzu GC 2010 Plus gas chromatograph with a flame ionization detector (PID), also with a capillary column "CPSil 88 for FAME" (Agilent Technologies) with a length of 100 m, an inner diameter of 0.25 mm, and a film thickness of 0.20 microns of non-mobile phase. To determine the polymorphism of kappa-casein genes and evaluate economically useful traits in animals with different genotypes of kappa-casein, only 60 cows were selected, including 20 Holstein cows, 20 Alatau cows and 20 black-and-white cows. The polymorphism of kappacasein genes was evaluated by PCR analysis. For further research, 3 subgroups of cows were formed in each group according to the principle of analogues, the results of genotyping and kappa-casein gene. The first group included cows with the AA kappa-casein genotype, the second - the AB genotype, and the third - the BB genotype. [ABSTRACT FROM AUTHOR]

Hybrid halide perovskites of the ABX3 composition are promising materials for use in optoelectronics and photovoltaics. To enhance the efficiency of structures based on perovskite, simulating the influence of the environment on the structures in laboratory conditions, irradiating them with various charged particles, has become a relevant task. This study explores possible irradiation methods for films with perovskite structures using various charged particles, such as alpha and gamma particles, protons, and electrons. Additionally, the impact of these processes on the properties and application domains of such structures is assessed. The research results showed that films based on perovskites (for example, CsPbBr3) have a very fast response (τ ∼5 ns) to irradiation with both alpha particles (with energy of ∼5 MeV) and protons. At the same time, they have the ability to fully restore to the initial conditions in a few hundred milliseconds after the cessation of irradiation. It has been shown that organic-inorganic hybrid perovskites are more sensitive to the action of an electron beam than inorganic onesAn increase in the dose of gamma irradiation leads to a decrease in the band gap (from 2,35 to 2,14 eV), a shift in the photoluminescence peak towards longer wavelengths and a decrease in the resistance of the grain boundaries. The effect of the gamma radiation dose on properties makes perovskite thin films very useful as sensor materials.

The upgraded Large Hadron Collider beauty (LHCb) detector will provide data taken in Run3 at the instantaneous luminosity of proton-proton collisions increased to 2⋅1033 cm-2s-1 at energies of up to 14 TeV. To ensure the safe operation of the experiment, a new beam and background Radiation Monitoring System (RMS-R3) was built. RMS-R3 is based on metal-foil detector technology developed at the Institute for Nuclear Research, National Academy of Sciences of Ukraine (Kyiv, Ukraine). The system comprises four detector modules with two sensors in each. Their frequency response is proportional to the flux of incident charged particles. The modules are located around the beam pipe at a distance of 2.2 m from the interaction point. The results measured during the Run3 in 2022 testify to the reliable operation of the system. Applying the asymmetry method, high-accuracy data were obtained on the localization of the interactions region and the beam and background contribution.

A system for quality assessment of micropixel detectors is presented. The system includes a laser scanning microprobe and a setup for studying the response of micro detectors to minimum ionizing particles. The results of the validation of the developed system indicate its suitability for assessing the quality of the latest monolithic active pixel sensors (MAPS), promising elements of large-area tracking systems for future high-energy physics experiments. Comparison of MAPS with the double-sided microstrip detectors of the CBM experiment (FAIR, Darmstadt) indicates the feasibility of the upgrade of its Silicon Tracking System using MAPS.

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The quality of food products depends not only on the technological parameters of production process, but also on storage conditions. Smart packaging controls storage conditions and tracks violations. The research objective was to review the use of sensors in food storage. The study featured publically available information on sensor-equipped smart food packaging. The information was obtained from open sources published in 2016–2021. The paper describes biosensors, chemical sensors, and indicators that determine some of the characteristics of food products and provide information to the producer, retailer, and consumer. Indicators proved to be the most promising type of sensors used in smart packaging. This type of sensor indicates the presence and concentration of various analytes through color change. The best indicators are those based on radio frequency (RFID), poison identifiers, compaction/leaks indicators, indicators of freshness/ripeness, etc. All the considered indicators visualize their data by changing color, which makes it possible to assess the quality of food products on the market. Sensor-based smart packaging is a promising direction in food industry because they make it possible to monitor and control product quality. Smart packaging allows consumers to check the freshness of products by themselves.

Gas-filled proportional detectors of ionizing radiation often contain such elements as thin anode wire, which make them sensitive to external acoustic or vibrational impact. This study investigates such sensitivity for the case of the proportional γ-radiation detectors filled with high-purity xenon gas. The detector demonstrates a dependence of its signal noise on the external acoustic wave frequency, the character of which most likely depends on the design of the detector, i.e. on such parameters as diameter and tension strength of the anode wire, etc. To suppress the negative impact of acoustic noise on the characteristics of the detector, the detector digital signal is processed in a Field-Programmable Gate Array board. The authors investigate the algorithm of «time windows», which allows separating (filtering) low-frequency noise in the output signal of a gas-filled detector, which arises due to the influence of external sound, from the useful signal, i.e. the ionization pulses. This approach allows performing spectral measurements of γ-radiation with a significant acoustic noise background, when detectors with a conventional analog spectrometric channel cannot handle the task.

The present work is concerned with finding optimal technological conditions for the synthesis of heterostructures with a metamorphic buffer for InGaAs/InP photodetectors in the wavelength range of 2.2–2.6 um using molecular beam epitaxy. Three choices of buffer structure differing in design and growth parameters were proposed. The internal structure of the grown samples was investigated by X-ray diffraction and transmission electron microscopy. Experimental data analysis has shown that the greatest degree of elastic strain relaxation in the InGaAs active layer was achieved in the sample where the metamorphic buffer formation ended with a consecutive increase and decrease in temperature. The said buffer also had InAs/InAlAs superlattice inserts. The dislocation density in this sample turned out to be minimal out of three, which allowed us to conclude that the described heterostructure configuration appears to be the most appropriate for manufacturing of short wavelength infrared range pin-photodetectors with high photosensitivity.

At the first stage, the objects of study were synthesized – silicon dioxide by the Stober method, where tetraethoxysilane was used as a precursor, and a nanocomposite ZnO-Au by the sol-gel method using the aqueous zinc acetate dihydrate as a precursor. At the second stage, the microstructure and morphology of the obtained samples were investigated by scanning electron microscopy on a «MIRA-LMH» scanning electron microscope (Tescan company) using both a classical secondary electron detector and additional detectors – intralens secondary electron detector and back-scattered electrons detector. As a result of the research, it was found that when using the secondary electron detector, practically no noise images with topographic contrast are obtained. When using the intralens secondary electron detector, images of only material contrast are created, without the influence of the surface relief. Also, the use of this detector made it possible to obtain high-quality images with a high resolution at a distance of 5 mm from the sample. When using a back-scattered electrons detector with a working distance to the sample of 8 mm and increasing the resolution of the microscope, the resulting images have low border contrast, but represent compositional information with high sensitivity. Thus, it was found that the intralens secondary electron detector with a working distance of 5 mm to the sample is optimal for obtaining clear images of the microstructure of the surface of nanomaterials at multiple magnifications.

Copyright of National Academy of Sciences of Armenia Reports / Doklady Nacionalnaâ Akademiâ Nauk Armenii is the property of National Academy of Sciences of the Republic of Armenia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper presents results of the radon survey carried out in preschool and school institutions in Dushanbe, Republic of Tajikistan. Radon concentration was measured using solid state nuclear track detectors Radtrak2. Track detectors were exposed for 3 months during the heating and warm seasons of the year in the same premises. In total, the measurements were performed in 200 premises of 14 kindergartens and 36 schools. The radon equilibrium equivalent concentration during the heating and warm seasons and the annual average radon equilibrium equivalent concentration were calculated. Annual average radon equilibrium equivalent concentration in surveyed buildings ranged from 42 to 331 Bq/m3 with the mean value of 98 Bq/m3 on the first floor and 56 Bq/m3 on the second floor. It was shown that both seasonal values and annual average value of radon equilibrium equivalent concentration in the premises on the second floor are lower than in the premises on the first floor. The annual average effective dose to children from exposure to radon and its progeny in the premises of schools and kindergartens in Dushanbe ranged from 0,64 to 1,64 mSv. The limit value of annual average radon equilibrium equivalent concentration in dwellings and public buildings is set to 100 Bq/m3 for newly built buildings and 200 Bq/m3 for existing buildings in the Radiation safety norms (NRB-06) of the Republic of Tajikistan. This limit was exceeded only on the first floors in one kindergarten during the heating season, in three schools during the warm season and in eight schools during the heating season. When comparing the results of measurements of radon equilibrium equivalent concentration with data on the geological structure of underlying rocks at the locations of the surveyed buildings, no regularity was found. Additional detailed measurements in the buildings, including basements, will help to identify the source of radon entry into the indoor air and to develop recommendations for implementing radon remediation actions separately for each building. The survey results were also used to develop a radon map of Dushanbe.

Copyright of Technical Diagnostics & Nondestructive Testing / Tekhnicheskaya Diagnostika I Nerazrushayushchiy Kontrol is the property of International Association Welding (Paton Publishing House) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A promising material for semiconductor detectors of ionizing radiation is CdTe:Cl which allows obtaining detectors with high resistivity ρ and electron mobility μn. During operation, the detector materials may be exposed to neutron irradiation, which causes radiation defects to form in crystal lattice and deep levels to appear in the band gap, acting as centers of capture and recombination of nonequilibrium charge carriers, thus reducing the detection capability. The aim of this study was to use computer simulation to investigate the mechanisms of the influence of such radiation defects on the electrophysical properties (ρ, μn) of CdTe:Cl and the charge collection efficiency η of radiation detectors based on this material. The simulations were based on the models tested for reliability. It was found that the increase of the CdTe:Cl resistivity ρ during low-energy neutrons bombardment and at the initial stages of high-energy neutrons bombardment is caused by an increase in the concentration of radiation donor defect Z (with an energy level EC – 0.47 eV), presumably interstitial tellurium, which shifts the Fermi level into the middle of the band gap. The sharp rise of ρ observed at high-energy neutron bombardment is probably caused by the restructuring of the crystalline structure of the detector material with a change in the lattice constant and with an increase of the band gap, accompanied by a change in the conductivity properties. The degradation of the detector properties of CdTe:Cl during neutron irradiation is due to the capture and recombination of nonequilibrium electrons at radiation defects: Te interstitial, Te substitutional at the cadmium site, on tellurium vacancies and cadmium vacancies. The degradation of electron mobility μn can be caused by the scattering of electrons at microscopic areas of radiation defect clusters. The increase in concentration of the defects over the volume of the crystal at their uniform distribution of up to 1016 cm–3 does not significantly affect the electron mobility at room temperature.

The history of the origin and formation of service cynology in Ukraine has quite interesting aspects. First of all, at the time when the territory of modern Ukraine was part of the Russian Empire, and eventually the Soviet Union, the police service cynology was originated in Ukraine. Thus, the beginning of the XX century was marked by the activities of H. M. Rudyi, who being a part of the detective police in 1904 organized the breeding station and began to use dogs to search for criminals. Besides, H. M. Rudyi organized training of a cynologist O. Erhant, who was objectively considered the first certified cynologist in Ukraine, and who graduated training in Schwelm. Heorhii Mykhailovych also developed an Instruction for the officials of Kyiv Detective Police, which defined the procedure and methods of involving dogs in the fight against crime. Further development of service police cynology throughout the Empire took place with the support and admiration of V. I. Lebediev, an official from the Ministry of Internal Affairs of the Russian Empire, who contributed to the creation of the All-Russian Society for the Promotion of Dogs in Police and Guard Service, as well as certain associations within the Empire. The author of the article has also studied the historical stages of the development of cynology, which are offered to be divided according to the criteria of methods of using dogs, as well as new turning points in training. Thus, the next stage has offered to allocate the time, when the process of dog training began to be based on the results of research accomplished by I. P. Pavlov, who described the reflexes in general (conditioned and unconditioned); indicative reactions and their nature; stimuli and their types; types and principles of higher nervous activity of dogs; processes of inhibition and excitation; deviations in the activity of the dog’s brain. All this has increased the arsenal of human abilities in the process of preparing dogs for service. Particular attention has been paid to the fact that police cynology during the wars is somewhat re-profiled, but does not lose its relevance. Unfortunately, the development of cynology after the Second World War underwent significant regression due to the changes in public attitudes and the post-war situation, but this did not prevent further use and improvement of the use of dogs. The emphasis has been placed on the peculiarities of the next stage in the development of cynology, which is associated with the development of odor methods of selection and preservation of odors, as well as the emergence of dogs-detectors who are further used in odor examination. It has been also noted that the current stage of development of cynology is very diverse, i.e. service dogs are used in almost all areas of law enforcement activity.

In the paper is shown that under the optimal conditions (1,5M NaCl), in the intensively accumulative mode of cultivation, the daily optical density of the cell suspension increases by 3,5-4 times, under conditions of high salinity (3,0M NaCl), by only 3 times. With an increase in the salinity of the mineral medium, the indicators of photosynthetic oxygen release are suppressed by 17%. It was found that the modification of cells with different concentrations (25-500 mkM) of 2,6 di-tret-butyl phenol under conditions of 1,5M NaCl and 3,0M NaCl salinity of the mineral growing medium contributes to a decrease in the content of synthesized pigments, suppression of the POL process, as well as an increase in catalase activity. It was revealed that, under conditions of high salinity of the mineral environment, the modified cells of Dunaliella salina IPPAS D-294 have increased functional resistance to the action of various acute doses of UV-B radiation. [ABSTRACT FROM AUTHOR]

This article describes the developed equipment that allows measuring the photoelectrical parameters of multielement photodetectors, specifically various formats of EMCCD (electron multiplying charge-coupled device) chips. The authors present the measuring techniques and test results on dark currents, output amplifier sensitivity, charge transfer efficiency, charge capacity and other parameters. The studies were conducted, both on the wafer and in the body, on samples of the following formats: 576×288, 640×512, 768×576, 1024×1024, and 1280×1024.

Solid-state ionizing radiation detectors based on high-resistance semiconductors can be used to monitor the safety of nuclear reactors. High-resistance CdTe and CdZnTe have very good electrophysical and detector properties. The objective of this study was to use computer simulation to determine how impurities and structural defects, as well as their clusters, affect electrophysical and detector properties of Cd1-xZnxTe (0≤x≤0.3). The calculations were based on well-tested models, the reliability of which was confirmed when comparing simulation results with well-known experimental data. It has been established that deep donors with energy levels near the middle of the band gap considerably extend the area of the high-resistance state of CdTe and CdZnTe, which is suitable for the creation of radiation detectors. The capture and recombination of non-equilibrium charge carriers occurs at the deep levels of cadmium vacancies owing to the influence of Ti, V, Ge, Ni, and Sn impurities. For this reason, such impurities are considered to be harmful, noticeably reducing the efficiency of charge collection η in CdTe and CdZnTe detectors. The decrease of electron mobility in CdTe and CdZnTe can be caused by the distribution heterogeneity of impurities (impurity clusters). When concentration of harmful impurities Ti, V, Ni, Sn, Ge does not exceed the content of the "background", provided that the impurities are distributed over the crystal uniformly, it is possible to obtain high-resistance CdZnTe of an acceptable detector quality. The obtained results could help determining conditions for producing CdTe and CdZnTe materials of high detector quality.

The existing methods for monitoring the performance of multi-criteria fire detectors do not provide for verification of their characteristics in the conditions of transition from smoldering to flame burning. The aim of the work is the development of the research methods of the environmental parameters during the transition from smoldering (pyrolysis) to flame combustion for simulation a test fire while checking the quality of multi-criteria fire detectors.A technique to conduct research of environmental parameters under conditions of heating wood samples of different sizes to a temperature of selfignition and burning crumpled and smooth paper has been developed.Changes in the concentration of carbon monoxide, specific optical density, and scattering ability during the transition from smoldering (pyrolysis) to flame burning of prepared wood and crumpled paper were studied for the first time.It is shown that the controlled environmental parameters during the transition from smoldering pyrolysis to flame burning change together. Conclusion: the speed of growth of the scattering ability of smoke decreases by 2.4 times, the speed of increase in the specific optical density and concentration of carbon monoxide increases by 2 and 5.3 times (respec-tively), during the transition from pyrolysis to flame burning of wood.

The proposed work demonstrates the results of creating and investigating the mathematical model of the source of fast neutrons. Computer modeling of the energy spectrum of fast neutrons was carried out for 239PuBe neutron source. The model of the source of fast neutrons has been developed. Neutrons in this model have an energy spectrum from 100 keV to 11 MeV with 100 keV step. Simulation is performed by the Monte-Carlo method. The model carrier is a computer program developed in the C++ programming language in the Linux operating system environment, using the Geant4 toolkit. All necessary classes describing low-energy models were used for the simulation of the passage of neutrons through materials of detectors. Those take into account the elastic scattering, inelastic scattering, radiative capture and fission. We consider these processes because models of processes implemented in our software will be also used for other problems of neutrons transport, for example, for passing neutrons through various substances, and for conducting virtual laboratory works. The PhysicsList class of our program contains classes G4NeutronHPElastic, G4NeutronHPElasticData, G4NeutronHPInelastic, G4NeutronHPInelasticData, G4NeutronHPCapture, G4NeutronHPCaptureData, etc. based on the NeutronHP model for neutron interactions at low energy, as well as the neutron data library G4NDL4.5. Diagrams containing energy spectra of a source of fast neutrons modeled in two ways are presented in the paper. The analysis of the obtained energy spectra is carried out. Virtual nuclear physics experiments are carried out with the aim of testing the elaborated neutron-matter interaction model. The processes occurring in scintillator substances during the passage of fast neutrons through them, have been studied. 109 neutrons were used as primary particles emitted isotropically, and we used our simulation results of 239PuBe neutron source to describe the initial energy spectrum. The created model of 239PuBe neutron source can be used for the investigation of scintillation detectors Bi4Ge3O12, CdWO4, Gd2SiO5 and others, as well as studying their characteristics. Processes in heavy oxide scintillators substance during the registration of fast neutrons can be studied using the developed model. It is shown that for registration of the flow of neutrons from 239PuBe neutron source, using Bi4Ge3O12 or CdWO4 scintillators is more preferable. Results of the virtual nuclear physical experiments satisfy the published experimental data.

Relevance. Currently, much attention is paid to development of efficient systems designed for processing, storing and transmitting large streams of information obtained in the form of images of space-time fields in such areas of human activity as cosmonautics, geology and geophysics, cartography, navigation, defectoscopy and many others. In most of these systems, when implementing detection algorithms, real images are used as reference images. For example, this is typical for isolation and tracing of the boundaries of reflected waves in images of seismic fields obtained by searching for oil and gas fields. Representation of reference images in the form of real images allows you to adjust the algorithm to a specific subject area, but complicates the assessment of the quality of the algorithm used and the conduct of its objective comparison with other algorithms that implement similar procedures. The aim of the research is to investigate the effectiveness of selection of the contour pattern of images by different detection algorithms based on a generalized complex criterion proposed by the authors of this work. This will allow us to approach objectively to selection of the best detection algorithm and the optimal values of its parameters for any subject area. Methods and means of research. When conducting experiments, the methods of stochastic modeling of space-time signals and fields were used. The computational experiment itself was conducted in the environment of the «KIM SP» software complex. Results. The authors have carried out the analysis of methods for evaluating search operators and localization of boundaries and summarized the main types of errors. On the basis of the proposed classification of metrics for the efficiency of contour detectors, a generalized comprehensive criterion for assessing the quality of selection of contour patterns in images is considered, the possible components of a generalized quality indicator and formal approaches to the choice of weighting coefficients of metrics are shown. The paper introduces the example of implementation of a generalized quality indicator, including five metrics; its effectiveness is investigated for three quasi-optimal contouring algorithms («Canny», «Marr» and «ISEF») at various noise levels. The conducted research allowed drawing the conclusions on the objectivity of the obtained results and giving recommendations on the use of contouring algorithms.

The first model independent results obtained by the DAMA/LIBRA-phase2 experiment are presented. The data have been collected over 6 annual cycles corresponding to a total exposure of 1.13 t  yr, deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. The DAMA/LIBRA-phase2 apparatus, ≃ 250 kg highly radio-pure NaI(Tl), profits from a second generation high quantum efficiency photomultipliers and of new electronics with respect to DAMA/LIBRA-phase1. The improved experimental configuration has also allowed to lower the software energy threshold. New data analysis strategies are presented. The DAMA/LIBRA-phase2 data confirm the evidence of a signal that meets all the requirements of the model independent Dark Matter (DM) annual modulation signature, at 9.5  C.L. in the energy region (1 - 6) keV. In the energy region between 2 and 6 keV, where data are also available from DAMA/NaI and DAMA/LIBRA-phase1 (exposure 1.33 t  yr, collected over 14 annual cycles), the achieved C.L. for the full exposure (2.46 t  yr) is 12.9 ; the modulation amplitude of the single-hit scintillation events is: (0.0103 ± ± 0.0008) cpd/kg/keV, the measured phase is (145 ± 5) d and the measured period is (0.999 ± 0.001) yr, all these values are well in agreement with those expected for DM particles. No systematics or side reaction able to mimic the exploited DM signature (i.e. to account for the whole measured modulation amplitude and to simultaneously satisfy all the requirements of the signature), has been found or suggested by anyone throughout some decades thus far.

Objective: To study the levels of radon accumulation in kindergartens in Sverdlovsk Region and to deter­mine the relationship between radon concentration, and building characteristics. To perform a detailed anal­ysis of radon entry and accumulation in the kindergarten, in which radon concentration exceeds the safety standards.Materials and methods: Track detectors REI-4 on the base of LR-115 film were used. Detectors were installed in playrooms and bedrooms for day nap. In each kindergarten, at least 3 rooms were examined. The measurements were carried out twice a year, during the warm and cold seasons. The duration of exposure of the detectors was 2–3 months in each season. The AlphaGUARD radon monitor was installed in the kinder­garten with a high level of radon concentration.Results: It is shown that the distribution of radon concentration in the kindergartens of the Sverdlovsk region can be described by a lognormal distribution with an average value of 60 Bq/m3, a geometric mean of 44 Bq/m3 and a standard geometric deviation of 2.23. A statistically significant differ­ence was found between the mean values of radon concentration in subgroups of buildings constructed at different periods. For the kindergartens constructed in 1950–1969, the average radon concentration was 85 Bq/m3, for buildings built in 1970–1989 – 54 Bq/m3. When comparing subgroups of rooms with different types of windows (all buildings, ground floors) it was found that in rooms with PVC windows, radon concentration is almost twice as high then in rooms with wooden windows. For the kindergarten, in which the annual radon concentration in the playroom was 620 Bq/m3, it was shown, that if the proper ventilation regime of this room is observed, the average radon concentration during the presence of children does not exceed 120 Bq/m3.Conclusions. Factors affecting the indoor radon accumulation in the kindergartens are the type of building materials associated with different periods of building construction and the type of windows. When radon concentration measured in kindergartens reach sanitary standards, it is advisable to conduct an additional study of the daily radon variations, since during the active operation of the premises (working hours) radon levels may be significantly lower

The review presents an analysis of modern methods and instruments for performing nonspecific detection of pathogenic biological agents in environmental objects. Discussed are technological characteristics of application of these methods for the detection of biological substances of protein nature in samples. The spectrum of means for non-specific PBA detection includes home-produced and foreign field devices based on protein contamination indication using various colorimetry variants. Technologies for remote and direct monitoring of environment for the presence of aerosols of biological nature are represented by hybrid lidar systems (biolidars) and biodetectors. For PBA nucleic acids tracing, the complexes based on DNA molecule binding with fluorophore with further fluorescence detection are described. Given are the examples of chemiluminescent analysis application in the developed automatic impurity detectors, as well as systems using bioluminescence. Based on the literature data analysis, put forward is a possible algorithm for indication of pathogenic biological agents when carrying out monitoring of the environment in zones of possible emergency situation occurrence and mass events holding.

As a result of the modernization of the DRG-05M dosimeter, a convenient device was obtained, which allows estimating the level of gamma- and X-ray radiation, beta-particles, and neutrons without changing the detector heads. Two devices were manufactured and a third one was prepared for metrological certification. [ABSTRACT FROM AUTHOR]

The cellular composition, the morphology of the components, and the screening function and evolutionary changes of the light-insulating apparatus of the camera-like eye of the terrestrial gastropod pulmonate mollusk Arion rufus were studied and evaluated using light and electron microscopy. According to all the considered characteristics, the light-insulating apparatus of A. rufus is typical for terrestrial pulmonate mollusks. Evolutionary transformations of the light-insulating apparatus, caused by the change in the mollusks' environment, are insignificant and affect the cellular composition, the morphology of pigmented cells and the isolation of the light-sensitive parts of pho toreceptor cells from each other. [ABSTRACT FROM AUTHOR]

The features of spectrum formation in CdTe (CdZnTe) detectors under gamma quanta radiation are presented. The main characteristics of a semiconductor detector, i.e. the energy resolution and the registration efficiency, are determined. The results can be used as a basis for physical and mathematical models of operation of CdTe (CdZnTe) semiconductor detectors for registration of gamma- and x-ray radiation over a wide energy range.

Copyright of News of Kazakhstan Science / Novosti nauki Kazahstana is the property of NCSTE (JSC National Center for State Scientific and Technical Evaluations) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Characteristics of 512-channel micro-detection system for the study of fast processes in metals during heating/cooling at high-speed radiography installation was presented. The position, width and intensity of diffraction peaks of the scattered X-rays was measured and displayed in real time depending on the temperature of the test sample (20 - 1500 °C). The position sensitivity of the system based on silicon microstrip sensors read out by commercial XDAS data acquisition system is 40 μm for the scattering angle of X-rays 30° < Θ < 75°.

A calibration technique for cryogenic temperature sensors is proposed and implemented. The experimental setup is based on the helium cryogenerator, providing calibration of the temperature sensors of various types in wide temperature range, including cryogenic band (25-100K). A condensation thermometer with hydrogen, neon, argon and xenon as working gases is used as a reference sensor. The experimental setup was successfully used for precise (0.1K precision) calibration of platinum resistive temperature detectors (Pt-100) for international nuclear physics experiments MuSun and PolFusion. The setup can also be used for calibration of temperature sensors of the other types.

Design of collimators and their effectiveness for the purposes of the fractionated mini-beam hadron radiation therapy were evaluated by Monte Carlo simulations. The calculations have been performed for proton, carbon and oxygen ion beams at the energies relevant for medical applications. Micropixel metal and hybrid detectors were tested for measuring charged particles intensity distribution in multi-beam structures shaped by slit or matrix collimators exploring low energy proton beam at the Tandem generator (INR NASU, Kyiv). The results obtained illustrate reliable performance of the designed collimators as well as hybrid and metal microdetectors for measuring and imaging in real time the proton intensity distribution over mini-beam structures.

Alpha spectrometry approach using solid state nuclear track detectors of CR-39 type is considered within the energy range 4-6 MeV. Experimental information obtaining stages are described from solid state nuclear track detectors irradiation procedure to follow analysis of individual tracks. Results of plutonium isotopes contained samples and dependence of minimal detectible activity from exposure time and spike (tracer) activity for nuclide are presented.

The paper deals with optical scheme for research of polarization state transformation at the junction of anisotropic waveguides. It consists of a light source, polarization controller, multifunctional integrated optical scheme (MIOS), single-mode fiber for input and output of optical radiation in MIOS and the polarization scanning Michelson interferometer. Optical radiation from the source of the plant comes through the polarization controller in one of the MIOS ports. Further, in one of the opposite ports the radiation is received by different fibers, polished at the angles of 19.5˚, 10.5˚ and 0˚. After that, the optical radiation gets into polarization Michelson interferometer. With that, the picture visibility is analyzed at different displacement of one arm upon which the value has been determined in the polarization conversion point connections. At the course of work it was obtained that the polarization state conversion at a splicing point rises with the slant angle deviation from its optimal value. Anisotropic waveguides splicing is one of the main tasks during fabrication of any fiber-optic sensor with integrated optical elements. The results of this work are of great interest for the wide range of specialists in the optical waveguides application field.

Clarification of the influence of defects on detecting properties of CdZnTe detectors and understanding of the behavior of defects under the influence of aggressive radiation environment are very important to improve detector performance. The objective was to study the charges collection efficiency and the resistivity of Cd0,9Zn0,1Te:Al detectors operating under the influence of low dose gamma-radiation. The study was carried out by computer simulation, where initial data were provided by the experiment results of other researchers. The possible reason for the change of measured signatures of defect levels in high resistance Cd0,9Zn0,1Te:Al during gamma irradiation and 1 month later is the change in compensation degree of the material. The changes in the properties of Cd0,9Zn0,1Te:Al detector have been researched depending on the concentration and energy level of the deep donor for different concentrations of deep acceptors, as well as on the degree of alloying with aluminum. The negative factor for registering properties of Cd0,9Zn0,1Te:Al detector is increased concentration of zinc vacancies, which may arise at manufacturing stage and under influence of γ-irradiation during operation. The degradation of properties of irradiated detector may occur due to the offset dependence of the resistivity on the aluminum dopant concentration N(Al) towards to higher concentrations of Al when the value of doping is not enough large. Only resistivity will be reduced and charge collection efficiency may increase. The increase in resistivity of Cd0,9Zn0,1Te and charges collection efficiency of the detector occur when there is a sufficiently high level of doping the material with aluminum.

The comparative efficiency analysis of two ways of multiplexing based on minimum and maximum selection methods has been carried out. It has been shown that minimum selection method is less effective than the maximum one for independent channels. Minimum selection method approaches efficiency of the maximum selection one when considering interchannel desired signal correlation. However this consideration implies the efficiency decrease of maximum selection method, while improving the efficiency of minimum selection one.

In 2016, St. Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev celebrates 60-th anniversary since its’ foundation. Mindful of the Institute as the research organization 60 years is not too much but it was exactly that time period which spanned radiation hygiene’s origination and development as science. The Institute was established only just 11 years after Hiroshima and Nagasaki bombings, against the backdrop of nuclear weapons tests when the awareness of ionizing radiation’s disastrous consequences for population and environment was not just confined to a narrow circle of specialists. By that time the famous F-1 reactor had already been in operation and new perspectives of nuclear energy peaceful use were lying ahead. There had been an urgent need for scientific studies on personnel and population safety, for development of research hardware, for special personnel in-service training etc. So the Institute’s creation was necessitated by life itself, by objectives unthinkable without a specialized scientific research organization. Since the very beginning, the Institute specialists mostly aimed at studying technogenic radiation sources. That was the very purpose of the Institute’s creation. Nevertheless almost simultaneously with that the Institute had initiated studies on natural radioactivity. New devices had been created in order to identify natural and technogenic radionuclides at such levels which are hardly achievable even these days. It will be demonstrated below that some of the 1970s and 1980s hardware developments retained their uniqueness. Mindful of the upcoming jubilee we consider it expedient to think back to the most outstanding scientists who had made a profound contribution into the establishment of the Institute as the contemporary scientific school of radiation hygiene and domestic hygienic science. This publication describes the infancy of the natural sources dosimetry laboratory. Subsequently it is planned to display the further advancement laboratory’s studies of natural radiation as one of population exposure major sources.

High-precision energy measurements of the most intense γ-transitions from the decay of 122Sb (Т1/2 = 2.72 days) have been performed with a γ-spectrometer. Using this data, the energies of the first excited states and corresponding deexciting γ-rays in 122Sn and 122Te were determined with precision up to a few electron volts.

The natural gas is naturally occurring hydrocarbon which consists mainly of methane and includes varying amounts of other hydrocarbons, carbon dioxide and other impurities such as: nitrogen, and hydrogen sulfide. It is used domestically and industrially as a preferable energy source compared to coal and oil. Because natural gas is found in deep underground natural formations or associated with other underground hydrocarbon reservoirs, there is a potential to contain radon as a contaminant. This work was designated to measure indoor radon concentrations in dwellings supplied with natural gas compared with those not supplied with it, where radon level was estimated using solid state nuclear track detectors (CR-39). The results showed that radon concentration was significantly higher in dwellings supplied with natural gas, where it was 252.30 versus 136.19 Bq ⋅ m-3 in dwelling not supplied with natural gas (P < 0.001). The mean values of radon exhalation rate was 0.02 ± 6.34 ⋅ 10-4 Bq ⋅ m-2 ⋅ h-1 in dwellings supplied with natural gas and 0.01 ± 0.008 Bq ⋅ m-2 ⋅ h-1 in dwellings lacking it. In addition, a significant difference was observed in the mean annual effective doses (4.33 and 2.34 mSv ⋅ y-1, respectively) between both groups. Conclusively, the data indicate that natural gas may represent a potential source of indoor radon.

Conversion-line and γ-ray intensities from the decay of 175Hf (T1/2 = 70 days) have been measured with π√2 magnetic β-spectrometer and two coaxial HPGe-detectors. The values of the internal conversion coefficient αK and penetration parameter λ for intraband magnetic dipole transitions γ114 and γ138 keV in 175Lu were determined.

One of the approaches for reconstructing the spectra of the mixed beta- and gamma-radiation, produced by wide band-gap semiconductor detectors, and the subsequent identification of radionuclides that are comprised in the mixture composition is a method based on various methods of spectral deconvolution. The presence of the detector response functions for each individual source of radiation is a key point in the studying such techniques. The response of TlBr- and CdZnTe-detectors to gamma-rays from 90Sr and 137Cs was simulated by Monte-Carlo method via Geant4 package. The computer experiments were conducted with using a β-filter and without it. It was shown that optimal thickness of the Al β-filter required for complete suppressing the conversion electrons in the 137Cs spectrum is 0.5 mm. The modification of 661.7 keV photopeaks with a using β-filter was investigated.