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Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 191
Author(s):  
Małgorzata Domino ◽  
Marta Borowska ◽  
Natalia Kozłowska ◽  
Łukasz Zdrojkowski ◽  
Tomasz Jasiński ◽  
...  

Infrared thermography (IRT) was applied as a potentially useful tool in the detection of pregnancy in equids, especially native or wildlife. IRT measures heat emission from the body surface, which increases with the progression of pregnancy as blood flow and metabolic activity in the uterine and fetal tissues increase. Conventional IRT imaging is promising; however, with specific limitations considered, this study aimed to develop novel digital processing methods for thermal images of pregnant mares to detect pregnancy earlier with higher accuracy. In the current study, 40 mares were divided into non-pregnant and pregnant groups and imaged using IRT. Thermal images were transformed into four color models (RGB, YUV, YIQ, HSB) and 10 color components were separated. From each color component, features of image texture were obtained using Histogram Statistics and Grey-Level Run-Length Matrix algorithms. The most informative color/feature combinations were selected for further investigation, and the accuracy of pregnancy detection was calculated. The image texture features in the RGB and YIQ color models reflecting increased heterogeneity of image texture seem to be applicable as potential indicators of pregnancy. Their application in IRT-based pregnancy detection in mares allows for earlier recognition of pregnant mares with higher accuracy than the conventional IRT imaging technique.


2021 ◽  
Vol 43 (4) ◽  
pp. 62-67
Author(s):  
P.G. Krukovskyi ◽  
D.A. Smolchenko ◽  
G.P. Krukovskyi ◽  
А.І. Deineko

Electric window heating has been used for some time in Europe and the Americas, but in Ukraine it only enters the market as an independent heating device and raises the question of its heating capacity in winter and the benefits of using them. There are several works in this field that determine the efficiency and contribution to the energy needs of an electric-heated window house, but it is necessary to answer more specifically the question of the heating capacity of such windows as a single heating system, for example rooms of certain sizes.In the work present the design, thermophysical processes occurring in such windows and, by computer simulation of the thermal state of the window with the selected typical room, the results of the study of the heating capacity of the windows, depending on the relative glazing area to the total area of the outer enclosure and the ambient temperature conditions not exceeding the maximum heat emission 450 /  and temperature 45 °С on the inner glass of the double-glazed window. the presented thermal model of the window with the room is implemented as a computer program with the possibility of a detailed analysis of the heating capacity of the window, depending on the parameters of the room and the outside temperature, as well as optimization of operational parameters to maintain comfortable conditions.


Buildings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 537
Author(s):  
Marina Gravit ◽  
Boris Klementev ◽  
Daria Shabunina

Cases of fire with highly flammable, combustible liquids and combustible gases with high potential heat emission at oil and gas facilities are assumed to develop as a hydrocarbon fire, which is characterized by the temperature rising rapidly up to 1093 ± 56 °C within five minutes from the test start and staying within the same range throughout the test, as well as by overpressure being generated. Although various fireproof coating systems are commonly used to protect steel structures from high temperatures, a combination of fire protection and cryogenic spillage protection, i.e., protection from liquefied natural gas (LNG), is rather an international practice novelty regulated by standards ISO 20088. Thanks to their outstanding features, i.e., ability to sustain chemical and climatic impact, these epoxy-based materials are able to ensure positive fireproof performance for steel structures in the case of potential cryogenic impact. The article discusses tests on steel structures coated with epoxy fireproof compounds, specifically PREGRAD-EP, OGRAX-SKE and Chartek 2218. The test records show the time from the start of cryogenic exposure to the said sample reaching the limit state, as well as the time from the start of heat impact to the sample reaching the limit state in case of hydrocarbon fire temperature.


2021 ◽  
Author(s):  
Yiqing Liu ◽  
Zhiwen Luo ◽  
Sue Grimmond

Abstract. Buildings are a major source of anthropogenic heat emissions, impacting energy use and human health in cities. The difference between building energy consumption and building anthropogenic heat emission magnitudes and time lag and are poorly quantified. Energy consumption (QEC) is a widely used proxy for the anthropogenic heat flux from buildings (QF,B). Here we revisit the latter’s definition. If QF,B is the heat emission to the outdoor environment from human activities within buildings, we can derive it from the changes in energy balance fluxes between occupied and unoccupied buildings. Our derivation shows the difference between QEC and QF,B is attributable to a change in the storage heat flux induced by human activities (∆So-uo) (i.e., QF,B = QEC − ∆So-uo). Using building energy simulations (EnergyPlus) we calculate the energy balance fluxes for a simplified isolated building (obtaining QF,B, QEC, ∆So-uo) with different occupancy states. The non-negligible differences in diurnal patterns between QF,B and QEC caused by thermal storage (e.g. hourly QF,B to QEC ratios vary between −2.72 and 5.13 within a year in Beijing, China). Negative QF,B can occur as human activities can reduce heat emission from building but are associated with a large storage heat flux. Building operations (e.g., open windows, use of HVAC system) modify the QF,B by affecting not only QEC but also the ∆So-uo diurnal profile. Air temperature and solar radiation are critical meteorological factors explaining day-to-day variability of QF,B. Our new approach could be used to provide data for future parameterisations of both anthropogenic heat flux and storage heat fluxes from buildings. It is evident that storage heat fluxes in cities may also be impacted by occupant behaviour.


2021 ◽  
Vol 2108 (1) ◽  
pp. 012059
Author(s):  
Tianlong Xiong ◽  
Chao Yang ◽  
Qing Cheng ◽  
Xianlong Yang ◽  
Shu Lin

Abstract The existing energy storage planning methods have the problem of imperfect equipment mathematical model, resulting in small installed capacity of renewable energy. An energy storage planning method of Park energy system based on multi-dimensional digital twin technology is designed. This article explains the basic connotation of multi-dimensional digital twin technology and park energy system, and obtains feedback information. Combined with the energy consumption of industrial users, the park’s electricity load is predicted. We used the multi-dimensional digital twin technology to construct the mathematical model of the equipment, extracted the energy conversion law, optimized the energy storage mode of the energy system, and achieved zero heat emission. Case analysis results: the average installed capacity of renewable energy after optimization is 2349.6 kW, 626.6 kW higher than that before optimization, indicating that the energy storage planning method integrating multi-dimensional digital twin technology has a broader application prospect.


2021 ◽  
Vol 10 (1) ◽  
pp. 40
Author(s):  
Guilherme Beraldi Lucas ◽  
Bruno Albuquerque de Castro ◽  
Paulo José Amaral Serni ◽  
Rudolf Ribeiro Riehl ◽  
André Luiz Andreoli

Three-Phase Induction Motors (TIMs) are widely applied in industries. Therefore, there is a need to reduce operational and maintenance costs since their stoppages can impair production lines and lead to financial losses. Among all the TIM components, bearings are crucial in the machine operation once they couple rotor to the motor frame. Furthermore, they are constantly subjected to friction and mechanical wearing. Consequently, they represent around 41% of the motor fault, according to IEEE. In this context, several studies have sought to develop monitoring systems based on different types of sensors. Therefore, considering the high demand, this article aims to present the state of the art of the past five years concerning the sensing techniques based on current, vibration, and infra-red analysis, which are characterized as promising tools to perform bearing fault detection. The current and vibration analysis are powerful tools to assess damages in the inner race, outer race, cages, and rolling elements of the bearings. These sensing techniques use current sensors like hall effect-based, Rogowski coils, and current transformers, or vibration sensors such as accelerometers. The effectiveness of these techniques is due to the previously developed models, which relate the current and vibration frequencies to the origin of the fault. Therefore, this article also presents the bearing fault mathematical modeling for these techniques. The infra-red technique is based on heat emission, and several image processing techniques were developed to optimize bearing fault detection, which is presented in this review. Finally, this work is a contribution to pushing the frontiers of the bearing fault diagnosis area.


Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7083
Author(s):  
Olga Gaidukova ◽  
Pavel Strizhak

A model was developed to research the critical conditions and time characteristics of the ignition of gel fuels in the course of conductive, convective, radiant and mixed heat transfer. MATLAB was used for numerical modeling. Original MATLAB code was established pursuant to the developed mathematical model. For gel fuel ignition at initial temperatures corresponding to cryogenic storage conditions with different heating schemes, a numerical analysis of interconnected processes of heat and mass transfer in the chemical reaction conditions and exothermic and endothermic phase transitions was conducted. The model was tested by comparing the theoretical results with the experimental data. Dependencies were established between the key process characteristic (i.e., the ignition delay time) and the ambient temperature when the following parameters were varied: emissivity, heat emission coefficient, activation energy and pre-exponential factor of the fuel vapor oxidation reaction. The critical values of the main parameters of the energy source were determined. For these values, gel fuel ignition conditions were consistently realized for each heating scheme. The critical heat fluxes necessary and sufficient for the ignition of typical gel fuels were determined.


2021 ◽  
Vol 11 (20) ◽  
pp. 9394
Author(s):  
Preeti Sirohi ◽  
Fahd N. Al-Wesabi ◽  
Haya Mesfer Alshahrani ◽  
Piyush Maheshwari ◽  
Amit Agarwal ◽  
...  

The growing demand for cloud technology brings several cloud service providers and their diverse list of services in the market, putting a challenge for the user to select the best service from the inventory of available services. Therefore, a system that understands the user requirements and finds a suitable service according to user-customized requirements is a challenge. In this paper, we propose a new cloud service selection and recommendation system (CS-SR) for finding the optimal service by considering the user’s customized requirements. In addition, the service selection and recommendation system will consider both quantitative and qualitative quality of service (QoS) attributes in service selection. The comparison is made between proposed CS-SR with three existing approaches analytical hierarchy process (A.H.P.), efficient non-dominated sorting-sequential search (ENS-SS), and best-worst method (B.W.M.) shows that CR-SR outperforms the above approaches in two ways (i) reduce the total execution time and (ii) energy consumption to find the best service for the user. The proposed cloud service selection mechanism facilitates reduced energy consumption at cloud servers, thereby reducing the overall heat emission from a cloud data center.


Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1205
Author(s):  
Liguang Zhu ◽  
Limin Zhang ◽  
Caijun Zhang ◽  
Zhiqiang Wang ◽  
Pengcheng Xiao ◽  
...  

The selection of lining material for a steel ladle is important to heat preservation of molten steel. Aerogel insulation materials have very low thermal conductivity, however, they are rarely used in steel ladles. In this paper, the application of a new silica aerogel material on the steel ladle insulation layer is tested, and a new calculation method is designed to study its insulation effect. In other words, the ladle wall temperature is obtained by finite element model (FEM) and experiments, then the heat emission from the ladle wall is calculated by the Boltzmann mathematical model according to the ladle wall temperature, and the temperature loss of molten steel is calculated inversely according to the heat emission of ladle wall. Compared with the original steel ladle (comparison ladle), the application effect is analyzed. Due to the stable heat storage of the ladle wall after refining, the validity of the models are verified in ladle furnace (LF) process. The results show that the new calculation method is feasible, and the relevant parameter settings in the FEM and Boltzmann mathematical model are correct. Finally, after using the new aerogel insulation material, the temperature of molten steel is reduced by 16.67 °C, and the production cost is reduced by CNY 5.15/ton of steel.


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