On the electronic properties of GaSb irradiated with reactor neutrons and its charge neutrality level

The electronic properties and the limiting position of the Fermi level in p-GaSb crystals irradiated with full-spectrum reactor neutrons at up to a fluence of 8.6 × 1018 cm−2 are studied. It is shown that the irradiation of GaSb with reactor neutrons results in an increase in the concentration of free holes to p lim = (5−6) × 1018 cm−3 and in pinning of the Fermi level at the limiting position F lim close to E V + 0.02 eV at 300 K. The effect of the annealing of radiation defects in the temperature range 100–550°C is explored

The development of adequate finite element models of load-bearing structures coating “Vnukovo-1 airport complex” to solve the problems of monitoring their technical condition

This article considers the issues of designing adequate finite element models of weight-bearing structures based on the roof structures of the Vnukovo-1 airport, which is made in the form of a spatial core structure. Additional actions on the covering structure model in terms of the strength checking calculation procedure are presented, its purpose is to make the adequate model for its further use in the design of structural health monitoring. The article presents the results of modeling, comparative research with the data of nature experiment

Methodological approaches to the assessment of public opinion during the overhaul of apartment buildings

In the article, using the example of a survey of residents of apartment houses (AH) on the quality of capital repairs, methodological approaches to assessing public opinion are considered. Processing the results of the survey showed that the definition of the coefficient of concordance is insufficient. It is shown that in order to assess the reliability of surveys conducted by the Delphi method, one should focus on achieving a greater confidence probability, and not on the value of the concordance coefficient. The survey showed that the priority factor for residents of apartment buildings of all ages and genders when assessing major repairs is the use of quality materials. For women of all ages, the issue of the cost of repairs was very important. Its importance for this group of respondents turned out to be almost at the level of the importance of the quality of materials. For the practical application of the results obtained, the weight coefficients of each studied factor were calculated for the total sample of respondents, which made it possible to create a methodology for express assessment of the quality of ongoing overhauls based on Harrington's verbal-numerical scales

Experimental and analytical study of an aluminium alloy bridge made of 1915T

In bridge design one of the main design criteria is fatigue. Better understanding, correlation and correct design rules are important to ensure safety. New code for the design of bridge structures made of aluminium alloys are being developed in Russian Federation. The authors tested a full scale pedestrian bridge for static and cyclic loading. The results of the experiment and numerical simulation are analyzed and presented in this article

Experimental and analytical study of an aluminium alloy bridge made of 1915T

In bridge design one of the main design criteria is fatigue. Better understanding, correlation and correct design rules are important to ensure safety. New code for the design of bridge structures made of aluminium alloys are being developed in Russian Federation. The authors tested a full scale pedestrian bridge for static and cyclic loading. The results of the experiment and numerical simulation are analyzed and presented in this article

The development of adequate finite element models of load-bearing structures coating “Vnukovo-1 airport complex” to solve the problems of monitoring their technical condition

This article considers the issues of designing adequate finite element models of weight-bearing structures based on the roof structures of the Vnukovo-1 airport, which is made in the form of a spatial core structure. Additional actions on the covering structure model in terms of the strength checking calculation procedure are presented, its purpose is to make the adequate model for its further use in the design of structural health monitoring. The article presents the results of modeling, comparative research with the data of nature experiment

On the electronic properties of GaSb irradiated with reactor neutrons and its charge neutrality level

The electronic properties and the limiting position of the Fermi level in p-GaSb crystals irradiated with full-spectrum reactor neutrons at up to a fluence of 8.6 × 1018 cm−2 are studied. It is shown that the irradiation of GaSb with reactor neutrons results in an increase in the concentration of free holes to p lim = (5−6) × 1018 cm−3 and in pinning of the Fermi level at the limiting position F lim close to E V + 0.02 eV at 300 K. The effect of the annealing of radiation defects in the temperature range 100–550°C is explored

Using labview software to collect and process measurement data as partof development of systems of monitoring of bearing structures Применение labview для решения задач сбораи обработки данных измерений при разработкесистем мониторинга несущих конструкций

Present-day urban construction trends make buildings taller and the urban environment denser. These developments result in the growth of negative effects produced on existing structures. That’s why the monitoring of the technical condition of structures is of vital importance. Now the most efficient way of forecasting and preventing emergency situations consists in the installation of automated monitoring systems operating in continuous and periodic modes.Monitoring systems may comprise various sensors, devices and measurement elements. Any signal must be coordinated to make sure that the data are accurate and reliable. Moreover, the proposed system (or network) composed of various items of equipment (often produced by various manufacturers) demands appropriate integrated software. The database of LabVIEW drivers can be employed for this purpose.LabVIEW environment is applied for the measurement, testing and management of applications that constitute embedded programming tools needed to develop complex applications designated for computer-aided measurements and data processing. The library of drivers is employed to assure the availability of the most common types of interfaces, sensors and devices. If a user lacks a particular driver, it can be either integrated or developed. The authors have successfully collected and processed the data in the LabVIEW environment of a measurement system based on tensometric sensors attached to experimental items of equipment.Обоснована необходимость проведения автоматического мониторинга несущих конструкций, рассмотрен алгоритм сбора данных, представлены наиболее распространенные типы преобразователей. Обосновано применение среды LabVIEW и приведена блок-диаграмма, написанная в среде LabVIEW, для сбора, обработки и записи измерительной информации

Neutron irradiation-induced modification of electrical and structural properties of GaN epifilms grown on Al2O3 (0001) substrate

The effects of fast neutron (up to 1.75 × 1020 f.n. cm–2) and fast plus thermal neutron (up to 3.5 × 1020 f.t.n. cm–2) irradiation on the electrical properties and crystal lattice of GaN films have been studied. It is shown that high-dose neutron irradiation induces a transition of n-type samples into a semi-insulating state with resistivity of ~1010 Ω cm at room temperature, while p-type films undergo transition to a high-resistance state. The subsequent irradiation of the samples leads to a decrease of resistivity to ~105 Ω cm at the final neutron fluence. Raman spectra show appearance of the disorder-activated Raman scattering modes at 210, 300 and 670 cm−1 linked to defects in Ga and N sublattices. X-ray diffraction measurements reveal an expansion of the GaN c-lattice parameter up to a saturation level of 0.42% at the final fluence, while the a-lattice parameter remains nearly unchanged. The initial value of c restores at 1000 °C annealing temperature, with the main annealing stage at 150 °C–400 °C. The significant role of thermal neutrons (E ≤ 0.1 MeV) in the damage build-up in GaN is shown