Main Design Parameters Research Articles

УДОСКОНАЛЕННЯ МЕТОДУ РОЗРАХУНКУ ПАРАМЕТРІВ ПОПЕРЕЧНОГО ДРЕНАЖУ МІЛКОГО ЗАКЛАДАННЯ НА АВТОМОБІЛЬНИХ ДОРОГАХ

An important aspect of the road structure strength and stability ensuring is the issue of subgrade favorable water-thermal regime providing during the service life. The article analyzes the results of research by scientists from different countries on the issues of taking into account the humidification regime and the arrangement of the drainage system on highways. One of the main design parameters of shallow transverse drainages is the distance between the drainage slots. The exact definition of this indicator determines the efficiency of water drainage from planar drainage and makes it possible to optimize the cost of drainage structures installation. In the presented work the questions of the existing normative base on climatological indicators definition and principles of shallow drainages calculation are generalized and tasks of researches on improvement and specification of distance between cross drainage apertures calculation method in such drainages are formulated. The authors propose a new solution to the problems. The developed method is based on the basic of non-uniform smooth-motion of a fluid in prismatic channels differential equation and the hypothesis of VI Chernomsky. The authors developed dependences to determine the distance between the transverse drainage slots in shallow drainages. The developed mathematical equations for the main parameters of transverse shallow drainage on characteristic sections of the highway adequately take into account the main factors influencing the process of moisture migration in the drainage layers and allow to solve problems of water-heat regulation of roads in a new aspect. The results of calculations of the distance between the transverse drainage slots, according to the proposed method, for the conditions of the first roadclimatic zone of Ukraine, the maximum total specific excess of water entering the drainage structure for the sand drainage layer with the value of filtration coefficient 4, 5 and 6 m / day are presented. The obtained data are compared with the calculation results according to the traditional method. Appropriate conclusions are made. KEYWORDS: DRAINAGE SYSTEM, DRAINAGE LAYER, DRAINAGE SLOTS, SHALLOW TRANSVERSE DRAINAGE, ROAD, WATERWAY, SUBGRADE.

Теоретичні дослідження процесу руху сипучих будівельних матеріалів при сушінні в киплячому шарі каскадної сушарки в будівництві

The paper considers the system of equations of movement of the material flow, which allows to determine the speed, trajectory of movement of particles, as well as the time of stay of particles in the free working space of the apparatus. Not only the hydrodynamics of flows, but also the kinetics of the drying process in fluidized bed devices (the particle changes its mass during drying, which is reflected in the mode of its movement) has a significant influence on the determination of the required residence time of the particles in the apparatus, which has contact actions with the cascade. A promising way to reduce material and energy costs during heat and mass exchange processes in a fluidized bed is the use of multi-stage countercurrent contact of the liquefying agent and the dispersed phase. Such processes are implemented in cascade-type devices. It should be noted that the analytical dependences presented do not yet allow a reliable description of the hydrodynamics of the movement of solid particles in a device with contact devices. This is due to the fact that the proposed analytical regularities do not take into account the influence of the main design parameters of the cascade contacts on the time the particles stay in the working space of the device. The efficiency of drying devices for drying materials in a fluidized bed largely depends on the flow field of the gas flow, the distribution of which in the working space of the device affects the profile of temperatures and concentrations of the dispersed (solid) phase in the gas flow. Determination of gas flow velocity fields in the working space of the fluidized bed apparatus in combination with calculations of the rate of transition of a dense layer of material into a fluidized state, conditions of expansion of the material layer, operating parameters of fluidization, and conditions of removal of material from the apparatus allows for optimal selection of the design characteristics of this type of apparatus. Consideration of the nature of the movement of the gas flow is important for establishing the regularities of its interaction with the solid phase. Determining the hydrodynamic conditions of flow movement makes it possible to mathematically describe the speed and residence time of solid particles in the apparatus.

Energy virtual networks based on electric vehicles for sustainable buildings: System modelling for comparative energy and economic analyses

This paper explores the implementation of the Building To Vehicle To Building (V2B2) scheme in European Countries, by evaluating the influence of weather conditions and local energy market prices on its energy and economic performance. The use of electric vehicles as energy vectors among buildings belonging to a virtual cluster is the key aspect of the V2B2 scheme: by exploiting mobile electric storage devices, renewable electricity produced by building integrated PV panels is shared among diverse users and consumed off-site. This novel energy management scheme has a twofold aim: i) promoting energy flexibility and efficiency in multiple buildings by improving the share of self-consumed renewable electricity at a cluster level and ii) reducing the interaction with the power grid. The proposed cluster includes two buildings, a house and an office space, and an electric vehicle, and it can be considered as the basic nucleus of human linked energy users.The energy and economic performance of the proposed V2B2 scheme highly depends on weather conditions and purchasing/selling electricity price. Therefore, to assess the impact of weather and energy prices on the system energy and economic performance, a comprehensive parametric analysis is conducted by varying the main design and operating parameters of the capacity of the key components of the investigated energy cluster, such as of buildings integrating PV panels and electric storage devices. The modelled and simulated scenarios refer to two different layouts simulated in several European cities, selected to consider different weather conditions and national electricity market prices. To identify the optimal V2B2 configurations, several energy and economic indicators of each simulated scenario are compared to a conventional reference one in which the novel energy management scheme is not implemented. Through the proposed V2B2 scheme, encouraging energy savings, from a minimum of 13.6% to a maximum of 71.2%, and economic outcomes are achieved.

Dissolved Air Flotation: A Review from the Perspective of System Parameters and Uses in Wastewater Treatment

The current issues of climate change and high freshwater demand worldwide have promoted the implementation of wastewater reclamation technologies. This study aims to review the efficiency of the dissolved air flotation (DAF) technique in a wide variety of applications in the agricultural, industrial, domestic, and municipal sectors, which have high freshwater consumption worldwide. We made a systematic review of the DAF technique in wastewater treatment in 2015-2021. We reviewed six indexed databases and governmental statistical reports; we used the keywords: dissolved air flotation, microbubbles, wastewater treatment, and the main operating and design parameters involved in the effectiveness of the flotation process. Additionally, we conducted a review of the most common synthetic coagulant studies used with DAF, as well as natural coagulants that promise to mitigate current climate change. Finally, we discussed advantages, disadvantages, and potential future studies. DAF to have considerable potential for wastewater treatment, as well as for waste utilization. The generation of large quantities of DAF sludge is a breakthrough for clean energy production, as it allows the use of this waste for biogas production.

OPTIMIZATION OF STATIONARY AND TRANSITIONAL OPERATING MODES OF THE ELECTRICAL COMPLEX IN METAL PROCESSING LINE

In the electrical complex “induction heater - deforming equipment”, the limiting performance of the complex is the induction heating unit. In this regard, an important task of increasing the effi ciency of the processing complex is to optimize both the design and operating parameters of the induction heating unit. It is shown that the main design parameter infl uencing the energy characteristics of the complex is the length of the heating system. When optimizing the total length of the heater, an iterative model of the process of induction heating of ferromagnetic billets is used. The power distribution algorithm along the length of a two-section heater is a piecewise continuous function. Optimization of the heater length according to the proposed method made it possible to reduce the heater length from 2.8 m to 2.1 m, i.e. by 25%. To search for eff ective control algorithms for non-stationary modes, a refi ned electrothermal model is proposed in the work. It takes into account the nonlinear dependence of the distribution of the power of the sources of internal heat release on the temperature distribution in the metal of the workpieces along the radial and axial coordinates. The problem of fi nding the optimal control of transient modes of a two-section induction heater of methodical action is formulated and solved. The results obtained provide a minimum of energy consumption for heating billets in transient modes under conditions of technological and energy constraints. Variants of starting the heater at various initial temperature states of the load are considered. The results of a comparative analysis of the eff ectiveness of the obtained control algorithms are presented. The structure of the power supply and control system of the induction heating complex is proposed.

Исследование сложных поверхностей винтовых движителей транспортных средств мехатронным профилографом

Introduction. The technology of investigation of screw propellers complex surfaces, which include the marine and aircraft propellers of vehicles, mechatronic profilers for the implementation of reverse engineering, is considered. A review of the scientific literature shows that at present the problem of monitoring complex surfaces of products at various stages of its life cycle requires further research, since the use of available devices and methods does not always provide the necessary accuracy, technological effectiveness and sufficient information on measurements. The purpose of the work is to develop a new technology for studying complex surfaces of propellers, which include marine and aircraft propellers of vehicles by means of a mechatronic profilograph to implement reverse engineering. Methods. The paper considers the implementation of the innovative technology for studying complex surfaces of propellers using the developed mechatronic profilograph. This ingenious mechatronic profilograph is designed to measure the profile and study the shape of complex surfaces of various products, as well as to determine the geometric and morphological parameters of these surfaces. On the basis of theoretical studies the main design and technological parameters are found and the hyperbolic dependence of the angular rate of the laser sensor movement on the scanning radius is determined for the developed mechatronic profilograph. For example, if a constant pitch of the trajectory along the Archimedes spiral is 2 mm, the value of the sensor angular rate should gradually decrease from the maximum value of 2 rad/s to the minimum value of 0.574 rad/s, i.e. by 3.484 times. Results and discussion. It is revealed that the use of cylindrical coordinates for processing the obtained data by a profilograph is logical and has a number of advantages. An express analysis of the propeller surfaces with rotary symmetry is carried out and differences in the shapes of the surfaces of the propeller blades by deviation values in the longitudinal and transverse directions for different radii are established. On the basis of the experimental data, a two-factor power model describing deviations with a determination coefficient of 0.967 is obtained, according to its analysis, it is clear that on average the angle of deviation in the perpendicular direction to the radius  - increases from 0 to 0.3, and the angle of deviation along the radius  increases from 0 to 5.4.

Mathematical modeling of forced oscillations of semidefinite vibro-impact system sliding along rough horizontal surface

The paper considers the motion conditions of a semidefinite vibratory system placed upon a rough horizontal surface. Such systems are sometimes called unrestrained or degenerate ones, and are usually used in various vibration-driven robots and capsules. Unlike the numerous existent investigations dedicated to a similar subject, the novelty of the present paper consists in the implementation of a crank mechanism for exciting oscillations of a double-mass vibro-impact system setting into planar locomotion a robot’s movable body. A general design diagram of the improved semidefinite vibro-impact system is proposed, and the corresponding mechanical diagram is considered. The differential equations describing the system sliding (planar locomotion) along a rough horizontal surface are derived. A thorough analysis of the main inertia-stiffness, design, and excitation parameters influencing the system motion conditions is carried out. Performing the numerical modeling in MathCad software, the dynamic behavior of the robot’s movable body is studied under the specified system’s parameters and operational conditions.

A modified fuzzy approach to project team selection

Selecting a team for executing a project is not an easy task. As any project involves monetary implications, management of a company employs a careful approach in choosing a project team. Several variations of Multi Criteria Decision Making (MCDM) Models are available in the literature and practice. We propose a modified intutionistic fuzzy approach to project team selection. We have combined the MCDM with dynamic weightage for each parameter. The main design parameters in this model are the conversion of input data into the fuzzified form, design of non - membership grade and the calculation of indeterministic values from membership and non- membership grades. Finally, the fuzzified output is converted into a crisp set, known as defuzzification. This method helps in determining the most skilled candidates in the order of their ability from a group of applicants.

Theoretical aspects of the calculation the main design parameters of the electric bird repeller

The problem of scaring away birds was born in ancient times and remains relevant to this day. Birds tend to places where they are comfortable and stay there. Therefore, to achieve maximum effect, new and effective designs of electric bird repellers are needed. Currently, the territories of cities and their outskirts serve as a habitat not only for people and domestic animals, they are also a habitat for numerous species of wild birds. In the settlements and in their vicinity, a specific fauna of birds has formed. Its main features are a limited number of species and a large number of individuals. This is due to the fact that few bird species were able to adapt to the specific living conditions in the city. However, those who were able to adapt found in the city a favorable environment for rapid and mass reproduction. The number of synanthropic birds in large cities reaches tens and hundreds of thousands of individuals [2]. Synanthropic birds are wild birds that constantly live in the vicinity of humans or have found favorable nesting conditions in the territory of settlements and their environs. Many spheres of life of synanthropic birds are directly related to human activities, since the food of synanthropic birds is anthropogenic in nature, because their diet usually includes seeds of cultivated plants and all kinds of food waste [3]. In each region, different species of birds prevail, but there are patterns that are characteristic of the entire territory of Russia. Almost everywhere, the main representatives of the synanthropic are house sparrows and doves. In the central part of the country, you can safely add the hooded crow to this list. When moving towards the west, the number of crows decreases markedly.

Improved Immune Genetic Algorithm to Optimize the Design of Wing Structure of Competition Aircraft

An improved immune genetic algorithm is used to design and optimize the wing structure parameters of a competition aircraft. According to the requirements of aircraft design, multi-objective optimization index is established. On this basis, the basic steps of using immune algorithm to optimize the main design parameters of aircraft wing structure are proposed, and the optimization of the wing parameters of a competition aircraft is used as an example for simulation calculation. The design variables in the optimization are the size of the wing components, and the optimization goal is to minimize the weight of the wing and the maximum deformation of the wing structure. Research shows that compared with traditional optimization methods; the improved immune genetic algorithm is a very effective optimization method. At the same time, a prototype is made to check the validity and feasibility of the design. Flight test results show that the optimization method is very effective. Although the method is proposed for competition aircraft, it is also applicable to other types of aircraft.

Effect of column strength deterioration on the performance of steel moment-resisting frames subjected to multiple strong ground motions

This study evaluates the effect of column strength deterioration caused by local buckling on the seismic performance of steel moment-resisting frames (SMRFs) considering multiple strong ground motions. Various SMRF models considering two main design parameters, i.e., the column width-to-thickness ratio and the column-to-beam moment capacity ratio, are analyzed by conducting an inelastic earthquake response analysis that simulates the occurrence of multiple strong ground motions. A column hysteretic model that takes into account the strength deterioration caused by local bucking is employed in this analysis. The numerical analysis results show that column strength deterioration may cause the shift to a weak story mechanism and weak story collapse under the excitation of multiple strong ground motions. The number of excitations that can be withstood by the structure (before collapse) varies among the models. The collapse fragility under multiple excitations is investigated to find the combination of design parameters that can achieve a certain acceptable performance.

Розробка технологічної схеми НВЧ – установки для сушіння зерна

In the agriculture of Ukraine, a variety of drying installations are used, the design of which should ensure uniform heating and drying of grain, while at the same time allowing to control the temperature and humidity in the grain mass. The choice of an appropriate dryer can significantly improve the quality of dried grain, increase production profitability, increase production, reduce drying costs, and reduce energy costs. Currently, the most common drying method is convective, the disadvantages of existing convective grain dryers are low efficiency, low specific moisture removal, uneven drying, high costs of the drying agent, high energy consumption. The purpose of the study is to develop a drying plant designed for high throughput. The use of grain drying technology using microwave electromagnetic fields provides a number of significant advantages over conventional dryers that use only a thermal agent. Grain drying technology using microwave electromagnetic fields can be used in combined dryers. The technological scheme of the drying installation is developed, which is based on the principle of microwave heating, which allows to intensify the external and internal transfer during drying. In the developed scheme the drying process takes place in three working zones. In the first zone, heating is carried out by irradiation with an electromagnetic field in the microwave range of seeds to a certain temperature, the second - the aging of the seeds, where moisture is released in the inter-grain space. In the third zone, the layer is blown by air flow with the organization of fluidization. The main design and mode parameters using the software environment "Flowvision" are determined. Key words: grain, microwave oven, dryers, installation, electromagnetic field

A Tunable Metamaterial Joint for Mechanical Shock Applications Inspired by Carbon Nanotubes

The significant developments of additive manufacturing and especially 3D-printing technologies have broadened the application field of metamaterials. The present study aims at establishing the main design parameters of a novel 3D-printed polymer-based joint. The proposed joint can efficiently absorb impact energy, relieving the material components from extensive plastic deformations. The design of the machine element is inspired by the molecular structure of carbon nanotubes and appropriately adjusted in such a way that it has the ability to partially transform translational motion to rotational motion and, thus, provide axial structural protection from compressive shocks. The utilized material is a photosensitive resin that is typically utilized in 3D manufacturing processes. Experiments are utilized to characterize the mechanical performance of the raw material as well as the static compressive behavior of the joint. Finally, finite element simulations are performed to test the developed design under impact loadings characterized by different frequencies. The damping capabilities of the metamaterial-based joint are revealed and discussed.

A Conceptual Design Methodology for e-VTOL Aircraft for Urban Air Mobility

Recent progress of electric systems has raised attention towards hybrid-electric and full-electric aircraft. Nevertheless, the current low battery energy density limits the application of these propulsive architectures to large transport aircraft. In the context of the general aviation category, full-electric aircraft for the so-called Urban Air Mobility scenario are gaining increasing interest. These air taxis, also called e-VTOL, are conceived to exploit vertical take-off and landing capabilities, to carry people from one point to another, typically within the same city. In this paper, a new conceptual design methodology for urban air vehicles is presented and applied to an innovative convertiplane, called TiltOne, based on a box-wing architecture coupled with tilt-wing mechanisms. Several TiltOne configurations have been designed according to the current regulations imposed by European Union Aviation Safety Agency, and sensitivity analyses have been carried out on the varying main design parameters, such as wing loading and propellers’ disk loading, as well as main top-level aircraft requirements. The results provide an overview for today’s operational capabilities of such aircraft and, in addition, depict possible scenarios for a near-future horizon, based on the assumption of increased performance levels for the electric powertrain components. In such scenario, two different concepts of operations are analysed and discussed: the first is based on a given design range, long enough to cover the urban distances; the second is conceived to exploit the capability of flying multiple shorter missions with a single battery charge. The designed TiltOne configurations derived from these different approaches are presented, highlighting their potential capabilities and possible drawbacks.

Theoretical investigation on integrating a torus oscillating body with a concentric perforated cylindrical system

In this paper, the hydrodynamic performance of a hybrid wave energy extraction (HWEE) system consisting of a torus oscillating body (OB) and a concentric perforated cylindrical system was investigated based on the linear potential flow theory. A linear power take-off system is assumed to extract wave power. To solve the diffraction and radiation problems, a theoretical model was proposed using the methods of separation of variables and eigenfunction matching. Through a contrastive study, it was found that the model with an arc-shaped perforated outer cylinder performs better than the model with a partially perforated outer cylinder in terms of effective bandwidth of capture width ratio and the hydrodynamic horizontal forces acting on them. The HWEE system with an arc-shaped perforated outer cylinder was studied particularly and optimized by examining the effect of several main design parameters, including the incident wave angle, the porosity and opening angle of the arc-shaped perforated outer cylinder, as well as the exterior radius and draft of the torus OB. It was also found that the torus OB has no negative effects on the stability of the concentric perforated cylindrical system, at least in terms of the horizontal wave forces acting on the structures.

The wave overtopping load on landward slopes of grass-covered flood defences: Deriving practical formulations using a numerical model

Overtopping waves exert a high hydraulic load on the landward slopes of flood defences leading to erosion of the grass cover and finally to a dike breach. The hydraulic load is an important variable in erosion models and a detailed description of the load is necessary to determine where and when the grass cover erodes. We use a numerical model to simulate the flow of a single overtopping event over a flood defence with a grass-covered crest and landward slope. The model results show that the flow velocity, the shear stress and the pressure are maximal at the landward toe and can be used to describe grass erosion by shear forces. For steep slopes, the flow separates at the crest line and impacts on the upper slope. The normal stress is maximal at the location of impact and describes the grass erosion by normal forces. Practical formulations are developed for the maximum flow velocity, the maximum pressure, the maximum shear stress, the maximum normal stress and the impact location using three main design parameters for the landward slope: the overtopping volume, the slope steepness and the slope length. The formulations are able to accurately predict the overtopping load with Nash–Sutcliffe model efficiency factors between 0.41 and 0.90. The model output and these new formulations are used to calculate the erosive power of the overtopping waves predicted by eight erosion indices to show how the simulated load can be used in erosion models.

Design of Ultra-Compact On-Chip Discrete Phase Filters for Broadband Dispersion Management

This paper provides an in-depth theoretical and numerical analysis of a group-velocity dispersion (GVD) management scheme for broadband waveforms using ultra-compact on-chip discrete spectral phase filters based upon waveguide Bragg gratings (WBGs) in a silicon-on-insulator (SOI) platform. Through this technique, mm-long discrete phase filters can be designed to impart a target arbitrary GVD profile on a high-rate (typically, $\geq\!10$ GHz) periodic pulsed waveform, including fully customized and extremely large second and higher-order dispersion terms (e.g., equivalent to 10,000 km of a standard single-mode fiber), over a broad frequency bandwidth (up to $\sim\!3$ THz, demonstrated here). The capabilities and limitations of this technique to impart a target GVD profile over an arbitrary (generally, non-periodic) broadband signal are also studied. We show that customized GVD lines can be efficiently implemented offering a net group-delay excursion in the hundreds-of-ps range using mm-long integrated discrete phase filters. Additionally, we suggest and numerically demonstrate a simple and practical strategy to improve significantly the performance of the discrete phase filtering approach for application on non-periodic waveforms, by combining the discrete phase filter with a suitable periodic resonance (frequency-comb) amplitude filter. An extensive tolerance analysis is conducted, and we conclude that the proposed SOI design framework is well within practical fabrication requirements as well as robust to the expected variability in the main WBG device design parameters.

Substantiation of optimum relative humidity of slurry when applying the batch-type gravity flow system for its removal

The batch-type gravity flow system for slurry removal is most commonly installed on the new and reconstructed pig farms. The newly designed system is characterized by the presence of plastic sewing pipes under each slurry-collecting canal. Such a system allows for complete automation of slurry removal and, under proper operation, mitigates the negative impact of pig farms on the environment through the lower annual output of slurry. The paper presents the calculation of the main design parameter of the system, such as the depth of slurry pits and the burial depth of longitudinal and transverse slurry collectors. Under the increase of pig manure humidity from 88% to 90%, the height of the residual layer decreases owing to lower manure shear stress in the part, where the manure moisture content increases. Under the relative humidity above 91%, the height of the residual layer in the pit increases rapidly due to the intensive stratification of slurry into fractions. Thus, the minimum height of the residual layer in the pit is achieved at the relative moisture content of 89-91%. Slurry should be accumulated in the pits to the 3/4 or 4/5 of the height (depth) of the pit. The accumulation period must be a multiple of the operating cycles of housing of various age and gender groups of pigs.

Kijksluiters: kijken naar gesprekken tussen apotheker en patiënt

Abstract Kijksluiters: watching conversations between pharmacists and patients As of 1975, Dutch patients receive a package insert with their medication. Due to extensive national and EU legal regulation efforts, the insert developed into a mandatory genre par excellence. However, its communicative functionality remained doubtful: the patient information leaflet has always been regarded as lengthy, complex and user-unfriendly. Recently, the Dutch Medicine Board has introduced a new, audiovisual medication instruction, the so-called Kijksluiter, that shows a video animation of a conversation about the medicine between a pharmacist and a patient. After a historical introduction, the second section of the paper surveys empirical studies that shed light on the main design parameters of the new genre: spoken instead of written information, animated speakers, dialogue instead of monologue. In the third part, we report on an observation study in which 16 users answer 9 scenario questions using a Kijksluiter video. The results indicate that Kijksluiters are not without user problems. Overall, two-thirds of the answers are more or less correct. Half of the participants first watched the video in its entirety before attending to the questions. The main problem this group encountered is: insufficient recollection of the relevant information. The other half of the participants navigated the Kijksluiter for each question, using the menu offering twelve small chapters. The main problems in this group was not finding the question-relevant chapter; but even after listening to the relevant information, some answers are incorrect. We conclude that, although Kijksluiter does not immediately solve all medication communication problems, its concise audiovisual format broadens the range of media available for medicine users.

REDUCING SEED DAMAGE IN THE RAW COTTON SEPARATOR

The article discusses the design features of the CX cotton separator. As a result of the analysis, the main reasons are established that lead to increased mechanical damage to seeds, and, as a consequence, to a decrease in the quality of products of the cotton ginning industry. The modernisation of the existing design of the separator is proposed by installing a visor at the outlet of the air flow into the separating chamber. On the basis of experimental studies, a regression mathematical model was obtained, which made it possible to assess the influence of the main design and technological parameters on the mechanical damage of seeds. It was found that this parameter, in addition to the position of the visor, is significantly influenced by the air flow rate at the entrance to the separation chamber and the separator performance. Recommendations on the choice of the position of the visor are obtained.