Engineering and Technology
The materials of The International Scientific – Practical Conference is presented below. The Conference reflects the modern state of innovation in education, science, industry and social-economic sphere, from the standpoint of introducing new information technologies. It is interesting for a wide range of researchers, teachers, graduate students and professionals in the field of innovation and information technologies.
TThe present paper proposes a model for evaluating geo-ecological protection technologies based on multi-criteria optimization and weighted convolution criteria, on the basis of which the method of calculation is developed, allowing to determine the PQ factor for different objects according to the selected technologies using the Mathlab environment. The work demonstrated the application of the technique in the case of materials made of ash foam concrete with densities and ash content from the incineration of sewage sludge. The determination of the optimum composition of solopenobeton is relevant for the design of noise shields in railway transport. The proposed simulation algorithm in the Matlab environment makes it possible to use the procedure of processing the raw data, using several options of their input: in the form of tables of the format. csv or manual input.
The results of the implementation of promising areas of construction of low-rise buildings are presented. The problems of improving the environmental safety and financial stability of agricultural construction through the introduction of effective systems, ensuring energy saving, creating comfortable conditions in the premises are considered. It is noted that in recent years, special attention has been paid to the environmental safety of the materials used and to reducing the negative environmental impact of systems using these materials. The rationale is given that the thermal resistance of the system should be based not only on the use of materials with low thermal conductivity, but also should offer a reasonable minimization of the joints between the products included in the insulation shells, as well as between the materials and the frame. In constructions with the use of polyurethane foam, a seamless insulation shell is formed, which has a high thermal stability. The low permeability of steam and wind and the moisture conductivity of polyurethane foam allows you to do without an additional steam barrier and wind protection, which improves the performance of the frame and its durability.
We consider a domed house-shed that combines a residential area and greenhouses. The planning solution of a multi-purpose domed house involves the formation of effective systems of insulation of internal walls that protect the living space of the interior from the heat-humidity and phyto-aggressive properties of the appearance of the greenhouse. It is established that the foam at an average density of 18-20 kg/m3 has the following characteristics: diffusion water absorption without coating is 0.44 kg / m2; diffusion water absorption with a metallic coating 0.37 kg / m2; water absorption by partial immersion in water for 24 hours 0,013 kg / m2; body water when fully immersed in water for 28 days 0.96%. The nature of the destruction of the contact surface "foam-metal" is cohesive in the adhesive layer, and the destructive stress is 12-17 kPa.
The results of the selection of compositions and technologies of composite material based on fine-ground high - activity waste production of Portland cement, mineral binder, additives based on polycarboxylates MC-6995, as well as polymer additives MC-Adhesive are presented. The concrete structure is reinforced with mineral fiber. MC-Adhesive is a polymer additive used to: significantly increase the bending strength; reduce the elastic modulus; increase the water resistance; increase the connectivity of concrete mixtures; manufacture of coatings with high requirements for abrasion resistance, low dusting and high resistance to aggressive substances. The purpose of the research is to prepare and conduct an experiment aimed at creating the foundations of cellular concrete technology based on waste from the production of mineral binders and mineral fibers.
The energy efficiency of heating systems depends on the cost of manufacturing insulation materials and components, their installation and operation of the insulation shell. As insulation materials for the insulation of heating networks, products based on stone wool, polyurethane foam, extruded polystyrene foam, foam rubber and polyethylene foam are used. The basic principles of calculating the thickness of the thermal insulation of the pipeline based on the value of the standard heat flow density are given on the example of using products based on polyethylene foam. The calculation of the heat flow from the surface of the thermal insulation structure is carried out at a given thickness of the thermal insulation layer, if it is necessary to determine the heat loss (or cold loss). The basis for the calculation is a mathematical model of heat transfer, a developed calculation algorithm and a computer program. Insulation cylinders or cylinders in combination with thermal insulation coils are used for small diameter pipelines. Rolled materials are used for insulation of large diameters.
Various methods of creating an insulation coating for frameless buildings are analyzed. It is confirmed that products based on polyethylene foam, such as mats and rolls, fully meet the above criteria. In addition, the possibility of obtaining a seamless joint during installation significantly increases the efficiency of the insulation coating by minimizing cold bridges and eliminating leaks when connecting individual insulation elements. The article presents information on the results of thermal imaging monitoring of frameless structures with an insulating coating based on polyethylene foam. It is shown that hot-air welding (using a heat gun) minimizes heat losses both at the joints of the sheets and in areas adjacent to the base and side walls of buildings.
The results of the study of the state of production of foam glass and the nomenclature of its products are presented. It is shown that it is advisable to use recycled glass obtained from bottle packaging, waste glass and double-glazed windows as raw materials for the production of foam glass. The features of the production technology of foam glass on specialized lines are described. The features of the technology are the composition of the charge and the temperature conditions of heat treatment. Currently, about 70% of the foam glass aggregate is used for roofs and stylobates; the rest is used in landscaping, road construction, foundations, and major repairs. The areas of application of foam glass can be significantly expanded in the direction of building systems, light aggregates, etc., which implies an in-depth study of the properties of this material.
The possibilities of solving engineering problems in the study of technological processes using the method of analytical optimization are considered. The essence of this method is to represent the technological process as a cybernetic system; statistical evaluation of each element of the system to obtain mathematical functions; analytical study of these functions and obtaining optimization dependencies. The research methods described in this article are implemented in the study of the technology of cellular concrete, expanded polystyrene concrete, cement polymer concrete and mineral wool products. As an example, the article considers the optimization of foam concrete technology.
The concept of energy efficiency includes energy conservation and durability of building systems. Ceramic brickwork offers the highest reliability and durability, and also belongs to the category of non-combustible. It is possible to improve the thermophysical properties of masonry made of ceramic products by using heat-insulating ceramics and, in particular, porous ceramic stones. The use of burn-out additives does not allow for a uniform distribution of porosity over the material. The use of expanded vermiculite fractions up to 0.5 mm allows you to form a uniform porosity. The results of the experiment allow us to determine the optimal density and density of ceramivermiculite and to evaluate the influence of technological parameters on its properties.
The analysis of the properties of products based on continuous basalt fiber, which provides high fire resistance, thermal insulation, vibration resistance, noise insulation, as well as chemical durability, including durability in the Arctic atmosphere and the impact of the marine climate. This fiber is the basis for construction fabric, canvas and special purpose products. It is proposed to manufacture insulation systems for engineering structures of special buildings using basalt fiber fabrics, canvas and fire-resistant rolled materials.
One of the aspects of the use of heat - insulating multifunctional shells-the preservation of cold-is investigated. This task is relevant for cold storage rooms, workshops and warehouses, where it is necessary to constantly maintain low temperatures, for sports facilities (for example, ice rinks and ski complexes). In all applications, the main goal is to achieve economic efficiency, which is expressed in functional results (preservation of the material that breaks down at positive temperatures) and in energy savings. The article also presents the experience of using heat, steam and moisture insulation shells based on polyethylene foam when equipping frameless and frame structures, sports facilities, as well as for snow preservation in ski resorts.
The use of a clay-gypsum mixture in the composition of a modified dispersed reinforced binder contributes to the creation of favorable environmental conditions and the formation of a comfortable climate inside agricultural premises, as well as increases the degree of protection of structures from fire. conditions. The technological properties of dispersed reinforced gypsum mixtures depend primarily on the composition of the modified clay-gypsum binder, the consumption of mineral fiber and its length. The fiber diameter in the range of 3.2-3.4 microns does not significantly affect the properties of the mixtures. Dispersed reinforcement in the range from 1 to 5% slightly affects the average density of clay-gypsum mixtures and plaster coatings based on them. The 20% increase in bending strength determines the greater resistance of plaster coatings to temperature effects.
The results of studies of the properties and features of the use of rolled polyethylene foam with or without a metallized coating are presented. The tensile strength of the product for products with a metallized coating is 80-92 kPa, without a metallized coating-80-87 kPa, and for the weld - 29-32 kPa. Insulation systems have been developed (which have found wide practical application) and a full-scale heat engineering assessment of these systems and the condition of the wooden frame in the building has been carried out. It is established that the thermal resistance of the structure is 2.96 m2 K / W, the heat transfer resistance is 3.12 m2 KK / V. The humidity of the frame wood is 7.7-7.8%.
The IEEE Russia North West Section, Pastukhov State Academy of Industrial Management (Yaroslavl), and the European Centre for Quality (Moscow) are pleased to present the Proceedings of the 2020 International Conference "Quality Management, Transport and Information Security, Information Technologies" (IT&QM&IS). The Conference was held in Yaroslavl, Russia on September 7-11, 2020, and it was proudly hosted by Pastukhov State Academy of Industrial Management. The Organizing Committee believes and trusts that we have been true to the spirit of collegiality that members of IEEE value whilst also maintaining a high standard as we reviewed papers, provided feedback and now present a strong body of published work in this collection of proceedings. The themes for this year's conference were chosen as a means of bringing together academics and industrialists, engineering and management research, manufacturing and teaching, and providing a basis for discussion of issues arising across the engineering and business community in relation to Quality Management, Information Technologies, Transport and Information Security aimed at developing engineers and managers for the future. The goal of these proceedings has been to present high quality work in an accessible medium, for use in a wide community of academics, engineers, managers, and industrialists, the community united by the key words Science, Education, Quality, Innovations in engineering. To achieve this aim, all papers submitted for publication in this journal of proceedings were subjected to a rigorous reviewing process.
7th International School and Conference "Saint-Petersburg OPEN 2020" on Optoelectronics, Photonics, Engineering and Nanostructures was held on April 27 - 30, 2020. The Organizer of the conference is the Alferov Federal State Budgetary Institution of Higher Education and Science Saint Petersburg National Research Academic University of the Russian Academy of Sciences. Initially, the School and Conference was supposed to be held in full-time format at the Alferov Academic University (Saint-Petersburg, Russia), as it happened in the past. However, due to the restrictions imposed by the city authorities on holding mass events due to the threat of the spread of the COVID-19 infection, the conference committees decided to move the conference to the online format. The conference consisted of poster reports presented by the participants and online oral presentations by invited speakers. Posters and video reports of the participants were posted on the conference website. Invited speakers made their presentations online. During their speeches, participants could discuss and ask questions in the chat. The School and Conference included a series of invited talks given by leading professors with the aim to introduce young scientists with actual problems and major advances in physics and technology.
The 10-Point Action Plan to catalyse a Circular Bioeconomy of Wellbeing is a call for collective and integrated action to global leaders, investors, companies, scientists, governments, nongovernmental and intergovernmental organisations, funding agencies and society at large to put the world on a sustainable path. The Plan is guided by new scientific insights and breakthrough technologies from a number of disciplines and sectors. It is articulated around six transformative action points (1–6) and four enabling action points (7–10), which mutually reinforce each other and need to be implemented in an integrated manner.
Recent statistics report that more than 3.7 million new cases of cancer occur in Europe yearly, and the disease accounts for approximately 20% of all deaths. High-throughput screening of cancer cell cultures has dominated the search for novel, effective anticancer therapies in the past decades. Recently, functional assays with patient-derived ex vivo 3D cell culture have gained importance for drug discovery and precision medicine. We recently evaluated the major advancements and needs for the 3D cell culture screening, and concluded that strictly standardized and robust sample preparation is the most desired development. Here we propose an artificial intelligence-guided low-cost 3D cell culture delivery system. It consists of a light microscope, a micromanipulator, a syringe pump, and a controller computer. The system performs morphology-based feature analysis on spheroids and can select uniform sized or shaped spheroids to transfer them between various sample holders. It can select the samples from standard sample holders, including Petri dishes and microwell plates, and then transfer them to a variety of holders up to 384 well plates. The device performs reliable semi- and fully automated spheroid transfer. This results in highly controlled experimental conditions and eliminates non-trivial side effects of sample variability that is a key aspect towards next-generation precision medicine.
We consider a linear-quadratic control problem where a time parameter evolves according to a stochastic time scale. The stochastic time scale is defined via a stochastic process with continuously differentiable paths. We obtain an optimal infinite-time control law under criteria similar to the long-run averages. Some examples of stochastic time scales from various applications have been examined.
Perfluorinated sulfonic acid (PFSA) polymer membranes are widely used as ion-conducting electrolytes in energy-conversion devices. The development of novel hybrid materials containing inorganic dopants offers the route towards optimization of the performance of the PFSA membranes. In this work, the effect of ultrasonic (US) treatment of the PFSA solutions in the presence of SiO2 nanoparticles on the characteristics of the cast hybrid Nafion+SiO2 membranes was studied for the first time. Upon ultrasonication of polymer solutions, the length of macromolecules is reduced, and the number of sulfo groups decreases. When polymer solutions are ultrasonicated in the presence of SiO2, they experience additional crosslinking due to the interaction of SiO2 with sulfo groups of the PFSA polymer. As a result, up to 20% of -SO3H groups appears to be excluded from the ion-exchange process, and the temperature corresponding to destabilization of ionic clusters is reduced. When a hydrophilic dopant is incorporated within pores, the overall water uptake of the hybrid membranes increases, and their proton conductivity is improved. Maximum conductivity (78.6 mS/cm) at 40°С in the contact with water is observed for the Nafion+1 wt% SiO2 membrane cast from polymer solutions upon the ultrasonication for 10 min. The membranes preserve their high conductivity at low relative humidity (4.1 mS/cm at 30°С, 30% RH), and this value is 1.7 times higher than that of the pristine Nafion membrane. Hydrogen permeability of the hybrid Nafion+SiO2 membranes appears to be lower than that of the Nafion membranes by 15%. Hence, US-assisted dispersion of dopant nanoparticles in the PFSA solutions allows preparation of hybrid membranes with improved transport characteristics.
Photoinduced nonequilibrium processes in nanoscale materials play key roles in photovoltaic and photocatalytic applications. This review summarizes recent theoretical investigations of excited state dynamics in metal halide perovskites (MHPs), carried out using a state-of-the-art methodology combining nonadiabatic molecular dynamics with real-time time-dependent density functional theory. The simulations allow one to study evolution of charge carriers at the ab initio level and in the time-domain, in direct connection with time-resolved spectroscopy experiments. Eliminating the need for the common approximations, such as harmonic phonons, a choice of the reaction coordinate, weak electron–phonon coupling, a particular kinetic mechanism, and perturbative calculation of rate constants, we model full-dimensional quantum dynamics of electrons coupled to semiclassical vibrations. We study realistic aspects of material composition and structure and their influence on various nonequilibrium processes, including nonradiative trapping and relaxation of charge carriers, hot carrier cooling and luminescence, Auger-type charge–charge scattering, multiple excitons generation and recombination, charge and energy transfer between donor and acceptor materials, and charge recombination inside individual materials and across donor/acceptor interfaces. These phenomena are illustrated with representative materials and interfaces. Focus is placed on response to external perturbations, formation of point defects and their passivation, mixed stoichiometries, dopants, grain boundaries, and interfaces of MHPs with charge transport layers, and quantum confinement. In addition to bulk materials, perovskite quantum dots and 2D perovskites with different layer and spacer cation structures, edge passivation, and dielectric screening are discussed. The atomistic insights into excited state dynamics under realistic conditions provide the fundamental understanding needed for design of advanced solar energy and optoelectronic devices.
Abstract Herein, we present a novel electrode platform for H2O2 detection based on the immobilization of recombinant Tobacco Peroxidase (r-TOP) onto graphite electrodes (G) modified with p-phenylenediamine (p-PD) diazonium cation grafted multi-walled carbon nanotubes (MWCNTs). The employment of both p-phenylenediamine moieties and covalent cross-linking by using glutaraldehyde allowed to enhance the sensitivity, stability and selectivity toward H2O2 detection, as well as preventing the enzyme inactivation due to the electro-Fenton reaction. This reaction continuously produces hydroxyl radicals, whose high and unselective reactivity is likely to reduce drastically the operating life of the biosensor. The protection against the electro-Fenton reaction is through cross-linking the enzyme in combination with interaction between the uncoupled -NH2 groups (mainly uncharged at pH 7, considering a pKa of 4.6) available on the electrode surface and the enzyme. In particular, the electrode based on the r-TOP/p-PD/MWCNTs/G platform showed a lower limit of detection of 1.8 µM H2O2, an extended linear range between 6 and 900 µM H2O2, as well as a significant increase in sensitivity (63.1 ± 0.1 µA mM-1 cm-2) compared with previous work based on TOP. Finally, the r-TOP/p-PD/MWCNTs/G electrode was tested in several H2O2 spiked food samples as a screening analytical method for the detection of H2O2.
The paradox of the modern labor market, when there is a shortage of engineering and technical personnel in the presence of a sufficient number of graduates of technical universities, is associated with a deformation of demand: only those specialists are in demand, which are either economically unprofitable or impossible to replace with technical devices, since so far artificial intelligence is not capable of creative creating innovations. The problem is that there are disproportionately few well-prepared schoolchildren among applicants to technical universities, and among university graduates there are many who have chosen a career outside the STEM sphere. There is no shortage of engineers, there is a shortage of highly qualified creative specialists. To train such specialists, it is necessary to increase the inflow of the most talented and creative students to technical universities, and then keep them in the STEM sphere. To test the hypothesis that a good way of attracting young people to the choice of an engineering career is to endow students with successful experience of technological invention, courses “Techno-Startup” for schoolchildren and “Technoinnovation” for students of technical universities were developed. The objectives of these courses are: to give students the experience of creating techno-innovation, to increase the motivation for a career in STEM among the most prepared students, to form critical thinking.
The process of poly(methyl methacrylate) (PMMA) matrix impregnation with mefenamic acid (MFA) in a supercritical carbon dioxide medium has been studied by the full atomistic classical molecular dynamics method. Simulations have been performed for two systems that differ in the polymer sample size (≈270 kDa and ≈1080 kDa) at 333 K and 40 MPa. The characteristics of the systems, such as the radius of gyration, end-to-end distance, mean squared displacement, radial distribution functions, average number of hydrogen bonds, and number of close contacts, have been analyzed and discussed. It has been found that by the end of the simulation (15 ns), the MFA loadings reach about 1.43 w/w % and 1.14 w/w % for the small and big PMMA samples, respectively. It was shown that the solute was distributed in the molecular form inside the polymer matrix. At the same time, when the CO2 molecules were removed from the systems and the simulation was performed in a canonical ensemble with the same cell length as in the previous isobaric-isothermal ensemble, the MFA molecules began to self-associate and get adsorbed on the polymer surface as hydrogen-bonded aggregates. In order to estimate the strength of the intermolecular interaction between the system components, ab initio calculations were performed. The calculated energies of the electron donor–acceptor (EDA) and hydrogen-bonded (HB) complexes can be arranged in the following order (in absolute value): ΔEEDA(PMMA-CO2)≈ΔEHB(MFA-CO2) < ΔEHB(PMMA-MFA) < ΔEHB(MFA-MFA).
High sensitivity imaging at the level of single photons is an invaluable tool in many areas, ranging from microscopy to astronomy. However, development of single-photon sensitive detectors with high spatial resolution is very non-trivial. Here we employ the singlepixel imaging approach and demonstrate a proof-of-principle single-pixel single-photon imaging setup. We overcome the problem of low light gathering efficiency by developing a large-area microstrip superconducting single photon detector coupled to a multi-mode optical fiber interface. We show that the setup operates well in the visible and near infrared spectrum, and is able to capture images at the singlephoton level.
The subject of this paper is microlasers with the emission spectra determined by the whispering gallery modes. Owing to the total internal reflection of light on the sidewalls, a high Q-factor is achieved until the diameter is comparable to the wavelength. The light emission predominantly occurs in the plane of the structure, which facilitates the microlaser integration with other elements. We focus on microdisk lasers with various types of the In(Ga)As quantum dots (QDs). Deep localization of charge carriers in spatially separated regions suppresses the lateral diffusion and makes it possible to overcome the undesirable effect of non-radiative recombination in deep mesas. Thus, using conventional epitaxial structures and relatively simple post-growth processing methods, it is possible to realize small microlasers capable of operating without temperature stabilization at elevated temperatures. The low sensitivity of QDs to epitaxial and manufacturing defects allows fabricating microlasers using III–V heterostructures grown on silicon.