Increasing consumption of meat and meat products worldwide is closely linked to improving the living environment for livestock. According to zoo experts, the appropriate microclimate in buildings leads to improved metabolic processes in their cultivation and contributes to their rapid weight gain. The issue of raising new-borns and young animals is especially relevant. Achieving optimal parameters of the microclimate in the premises, together with the necessary veterinary care for new-borns reduces stress and mortality in them. The above requires the implementation of new and modern engineering solutions in the design and construction of livestock buildings. The use of numerical simulations, through CFD programs for modelling and solving engineering problems, as well as the creation of adequate mathematical models, is a prerequisite for reducing the time and resources to solve a problem. Based on the accumulated experience of the authors on the microclimate in livestock farms in this publication, a numerical simulation of air exchange in a livestock building for breeding sows with young piglets is presented. The physical model, research and analysis are realized in the middle of Ansys Fluent. Two models of air exchange organization in the livestock building are proposed. The obtained data on the temperature and speed fields in the building will lead to an improvement of the microclimate in the considered site. In addition, they could serve as a basis for conducting the next series of computer simulations. The built models can be adapted for other building constructions for breeding other types of animals. The analysis of the data and a more in-depth examination of the factors related to animal husbandry could help to increase pork yields on livestock farms

This paper discusses the application of Fresnel Lens Concentrator for Solar Water Heater which is a case study in Indonesia. The purpose of this study was to find an empirical equation of the relationship between Direct Normal Irradiance (Ib) and focal point temperature (Tf). The research location is Latitude: 7.9553 °S and Longitude: 112.6145°E. The SM-206 solar power meteris used.The Fresnel lenses are made of PMMA material. Its specifications are: diameter=1000 mm; weight=2 kg; thickness=2 mm; groove pitch=0.5 mm and focal length=880 mm.The main experimental setup consists of a PMMA Fresnel lens and a receiver. The conical cavity receiver has specifications; geometric concentration ratio,CRg=8, and V=2 Liters. Temperature measurement is done using a temperature data acquisition system. The K-type thermocouple is used to measure: 1) ambienttemperature (Ta); 2) the focal point temperature (Tf); 3) receiverwall temperature (Tr); 4) watertemperature (Tw). The experiment obtained the results of the empirical equation for the relationship between Direct Normal Irradiance (Ib) and focal point temperature (Tf). The increase in solar radiation produces a focus temperature, exponentially. At DNI 858 W/m2 it can produce a focal temperature of up to 1064 °C. The efficiency of the receiving cavity of the thermal cone which contains 2 litres of water and CRg=8 under conditions of relatively Direct Normal Irradiance ( =675 W/m²) is about 10.61 %. Furthermore, the energy that can be generated in heating water is 0.17–0.32 MJ, in 100 minutes. Heat convection and radiation loss can be reduced by adding an insulating layer to the walls and coating the surface with black

The productivity of an employee has a crucial role for the company. The higher the level of productivity, the higher the profit they can provide for the company. Ergonomic furniture is one of the supporting examples in increasing employee productivity. Designing ergonomic furniture is the effort taken by the company to boost the employee's productivity. The ergonomic furniture can provide comfort to the employee and minimize the occurrence of Musculoskeletal Disorders (MSDs). The provided coziness will increase the level of concentration so that the performance of the employee will be increased too. The existence of ergonomic furniture will offer benefits to the company. Therefore, companies are required to provide adequate facilities and infrastructure to support employee activities. One of the company's facilities is a table and chairs. Tables and chairs must be designed ergonomically, considering that both facilities will continually be used within 8 hours per day. This research aims to utilize anthropometric measurement as a design tool for ergonomic work furniture. The anthropometric measurement was conducted on 85 employees and used 11 body dimensions as a parameter. These body dimensions consist of a supine hand, sitting, forward pinch-grip reach, elbow height, shoulder width, pelvic width, buttock-knee length, knee height, shoulder height, sitting, length of elbow to toe, thigh clearance, and palm width. The 5th percentile was used for four dimensions in this research, while the rest used 95th. The results of this research are expected to minimize the possibility of various health problems caused by the un-ergonomic working furniture so that the employee's performance will be improved too

The relevance of the study is conditioned by the need for qualitative consideration and analysis of the basic architectural principles taken as a basis for the development of a hardware and software complex designed to conduct work on remote radiosounding of the ionosphere. The purpose of this study is to analyse the basic principles of building the architecture of a hardware and software complex for ground-based ionosphere radiosounding, to create a high-quality scientific base for further research of various processes occurring in ionospheric plasma, changes in its structure and state. The basis of the methodological approach in this study is a combination of methods of system analysis of the basic principles of building the architecture of a hardware and software complex of ground-based ionosphere radiosounding with an analytical investigation of the features of the radiosounding procedure, to obtain the most objective and reliable information about the real state of this atmospheric layer of the Earth and the processes occurring in it. The results obtained emphasise the importance of practical issues of creating a high-quality architecture of a hardware and software complex for ground-based radiosounding of the atmosphere and indicate the presence of a systemic relationship between the quality of the hardware and software complex, the presence of disturbances in the ionosphere, and the nature of these disturbances. The results obtained have significant practical significance for developers of modern radiosounding systems of atmospheric layers, and for operators of systems of this kind, whose direct duties include monitoring the state of these systems and maintaining an adequate level of their operability to conduct scientific experiments

Inspection of defects in the printed circuit boards (PCBs) has both safety and economic significance in the 4.0 industrial manufacturing. Nevertheless, it is still a challenging problem to be studied in-depth due to the complexity of the PCB layouts and the shrinking down tendency of the electronic component size. In this paper, a real-time automated supervision algorithm is proposed to test the PCBs quality among different scenarios. The density of the PCBs layout and the complexity on the surface are analyzed based on deep learning and image feature extraction algorithms. To be more detailed, the ORB feature and the Brute-force matching method are utilized to match perfectly the input images with the PCB templates. After transferring images by aiding the RANSAC algorithm, a hybrid method using modern computer vision algorithms is developed to segment defective areas on the PCBs surface. Then, by applying the enhanced Residual Network –50, the proposed algorithm can classify the groove defects on the surface mount technology electronic components which minimum size up to 1x3 mm. After the training process, the proposed system is capable to categorize various types of overproduced, recycled, and cloned PCBs. The speed of the quality testing operation maintains at a high level with an average precision rate up to 96.29 % in case of good brightness conditions. Finally, the computational experiments demonstrate that the proposed system based on deep learning can obtain superior results and it outperforms several existing works in terms of speed, precision, and robustness

Using the method of statistical modeling of pipeline reliability, the statistical model for forecasting the dependence of the failure parameter of pipelines of main heating networks on the service life and diameter was developed and analyzed. This method includes two techniques. The first allows to obtain predictive dependences of pipeline reliability indicators for systems that include sections of different diameters with different service life periods and actual data on damage over several years. The second increases the correctness of the obtained dependences by optimizing the service life step in the study of damage to heat pipes. As a result of the study, the dependence of the reliability of main pipelines on the service life and diameter was established. The condition and forecast values of the specified indicator of reliability of main heat pipelines, and also dynamics and range of its changes are defined. The average value of the failure rate parameter increases from 0.23 1/km year (diameter 300 mm) to 0.62 1/km year (diameter 800 mm), which is 2.7 times larger than the pipes with the diameter 300 mm. The multiplicity of changes in the value of the parameter of the flow of failures was also established in accordance with the change in the diameter of the pipelines. According to the developed statistical model the dependence for calculation of the forecast of quantity of damages of the main heat pipelines according to their service life, diameter and length is established. This will increase the reliability of heating systems and effectively plan the cost of material, technical and labor resources. The given method can be used to assess the forecast of the reliability of pipelines, respectively, of their diameters for other engineering systems and networks

The transfer of information by telecommunication channels is accompanied by message hashing to control the integrity of the data and confirm the authenticity of the data. When using a reliable hash function, it is computationally difficult to create a fake message with a pre-existing hash code, however, due to the weaknesses of specific hashing algorithms, this threat can be feasible. To increase the level of cryptographic strength of transmitted messages over telecommunication channels, there are ways to create hash codes, which, according to practical research, are imperfect in terms of the speed of their formation and the degree of cryptographic strength. The collisional properties of hashing functions formed using the modified UMAC algorithm using the methodology for assessing the universality and strict universality of hash codes are investigated. Based on the results of the research, an assessment of the impact of the proposed modifications at the last stage of the generation of authentication codes on the provision of universal hashing properties was presented. The analysis of the advantages and disadvantages that accompany the formation of the hash code by the previously known methods is carried out. The scheme of cascading generation of data integrity and authenticity control codes using the UMAC algorithm on crypto-code constructions has been improved. Schemes of algorithms for checking hash codes were developed to meet the requirements of universality and strict universality. The calculation and analysis of collision search in the set of generated hash codes was carried out according to the requirements of a universal and strictly universal class for creating hash codes

The viral transmission in public places and transportations can be minimized by following the world health organization (WHO) guideline. However, the uncertainty in a dynamic system complicates the social engagement to the physical distancing regulation. This study aims to overcome this obstacle in MRT stations and train by developing an adaptive queue line system. The system was developed using low-cost hardware and open-source software to guide passengers using visual information. The system works by capturing seat images and identify the presence of humans using a cloud machine learning service. The physical representation of MRT was translated to data representation using the internet of things (IoT). The data then streamed using an asynchronous API with a representative endpoint. The endpoint is then accessed by a display computer in the destination station platform to provide visual information. The visual information was ergonomically designed with visual display principles, including the minimum content load, layout, color combination, and dimension of contents. The design of the system was evaluated by Markov simulation of virus transmission in train and usability testing of the visual design. The implementation of the system has balanced the queue line capacity in station and crowd spots distribution in MRT. The system was effective due to the visual cortex manipulation by visual information. Consequently, the aerosol and falling droplets' viral transmission radius can be reduced. Accordingly, the chance for airborne transmission can be lowered. Therefore, the adaptive queue line system is a non-pharmaceutical intervention of viral transmission diseases in public transportation

To implement effective cow milking, it is necessary to take into account the peculiarities of the milk flow process, the milking machine's adaptability to perform the given technological functions. The aim of research is to establish changes in the design and technological parameters and physical and mechanical properties of teat cup liner of milking machines during its testing and in production conditions. The results obtained will make it possible to make a rational choice of rubber, ensure an efficient milking process during its service life. It is found that the tensile strength of silicone teat cup liner at the beginning of operation was 1.6 times higher than that of a rubber compound, and after 6 months. operation – 1.7 times. With respect to the relative elongation, this difference was 1.4 times, and after operating time – 1.3 times. Studies have proven that rubber during operation changes its physical and mechanical properties: the length of the active part increased by 3.1 mm; wall thickness – 0.2 mm. It is found that the most intensively elastic properties of teat cup liner changed during the first 10–20 days. After 10 days, the closing vacuum increased by 16.6 % compared to the initial one, and after 20 days by 23.3 %, which amounted to 8.57 and 9.06 kPa, respectively. Up to 420 hours of operation, the clamping vacuum reached 11.3 kPa, which is 5.8 % lower than the requirements for toughening teat cup liner for rejection. In general, over the period of experiments, the average value of the vacuum of closing the opposite walls of teat cup liner increased from 7.35 to 12.43 kPa, which is 3.6 % higher than the norm (12 kPa). As a result of experimental studies, the regularity of the rubber tension force depending on the operating time in the form of a fourth degree polynomial is obtained. It is found that after 150 hours of operation, the tensile force of teat cup liner decreased by 21 %

This paper presents the results of studying the motion of a liquid layer along the walls of a vertically installed pipe under the action of gravity. Two-dimensional boundary layer is formed by the fluid motion relative to the hard wall on surfaces of structures (pipes, turbines, heat-and-mass transfer equipment, aircrafts, ships, etc.), which are of positive interest in engineering practice. Further upgrading of the above-mentioned structures is possible only by increasing accuracy of momentum in the boundary layer, heat and mass transfer rates calculation. It is confirmed that in the boundary layer transfer phenomena intensity (perpendicular to the wall) is due to the fluid particles velocity distribution regularities in the cross-section of the layer. Fluid velocity distribution regularities in turn are conditioned by Reynolds number according to current notions. The principal method of quantitative analysis of turbulent flow in a boundary layer suggested by Reynolds continues to be the velocity and pressure fluctuations averaging method for some timespan. The suggested model of fluid movement enables to prognosticate conditions under which in cross-sections of the boundary layer reshaping of velocity profile takes place, to carry out analytic calculation of such hydrodynamic characteristics as mean velocity of motion, layer thickness and shearing stresses acting on the wall. The difference between the suggested methods developed for calculation of flow parameters from the well-known ones is in that that calculations are made based on an integrated approach regardless of such conceptual definitions as laminar and turbulent regimes widely used in modern hydrodynamics. Obtained results and design formulas known in the literature have been compared. It has been found that the thickness of the sliding layer, determine by the proposed calculation formula, 1.17 times smaller than that determined by the currently used formula