scholarly journals Impact of Thermal Dissipation on the Lighting Performance and Useful Life of LED Luminaires Applied to Urban Lighting: A Case Study

Juan de Dios Unión-Sánchez ◽  
Manuel Jesús Hermoso-Orzáez ◽  
Manuel Jesús Hervás-Pulido ◽  
Blas Ogáyar-Fernández

Currently, LED technology is an established form of lighting in our cities and homes. Its lighting performance, durability, energy efficiency and light, together with the economic savings that its use implies, are displacing other classic forms of lighting. However, some problems associated with the durability of the equipment related to the problems of thermal dissipation and high temperature have begun to be detected, which end up affecting their luminous intensity and the useful life. There are many studies that show a direct relationship between the low quality of LED lighting and the aging of the equipment or its overheating, observing the depreciation of the intensity of the light and the visual chromaticity performance that can affect the health of users by altering circadian rhythms. On the other hand, the shortened useful life of the luminaires due to thermal stress has a direct impact on the LCA (Life Cycle Analysis) and its environmental impact, which indirectly affects human health. The purpose of this article is to compare the results previously obtained, at different contour temperatures, by theoretical thermal simulation of the 3D model of LED street lighting luminaires through the ANSYS Fluent simulation software. Contrasting these results with the practical results obtained with a thermal imaging camera, the study shows how the phenomenon of thermal dissipation plays a fundamental role in the lighting performance of LED technology. The parameter studied in this work is junction temperature (Tj), and how it can be used to predict the luminous properties in the design phase of luminaires in order to increase their useful life.

2020 ◽  
Vol 866 ◽  
pp. 82-95
Guang Yao Li ◽  
Yang Cao ◽  
Tao Yue Yang ◽  
Wen Qing Ma

Aiming at the problems of large temperature differences and inconsistent baking speeds at different positions in the tobacco chamber of the tobacco baking room, this paper proposes a complex structure processing technology of fan vent. according to the structure and drying principle of the baking room, ANSYS fluent simulation software was used to analyze the processing parameters of the heat flow field inside the baking room. combining the characteristics of positive and negative air supply baking, the processing and manufacturing parameters of the baking room were optimized, and then the baking comparison test was performed. The results show that: the forward and reverse air-baking method and the complex structure reduces the temperature difference in the interior of the smoke chamber; the forward and reverse air-bake method reduces the baking time by 11 hours, and reduces the coal consumption and power consumption by 12.6%, 48.5%, the standard deviation of temperature monitoring points in the baking room decreased by 44%.

2017 ◽  
Vol 2 (87) ◽  
pp. 66-74
J. Nowacki ◽  
N. Sieczkiewicz

Purpose: Analysis of non-destructive testing systems polymer composite in terms of current solutions in the area of methodology and devices. Analysis of contemporary standards for non-destructive testing of polymer composites established by ASTM. Analysis of Flir ONE camera capabilities in non-destructive testing composite carbon-epoxy composites. Design/methodology/approach: The thermal imaging tests of the carbon-epoxy composite discontinuity were carried out using a thermal imaging camera and Flir One accessory for an iOS phone. The tests were performed on carbon-epoxy composite samples measuring 100x100 mm. In order to simulate the discontinuity in a sample by the Resin Transfer Molding (RTM) method, a 30x30 mm PTFE film was inserted between the reinforcement layers. The thickness of the sample with discontinuity was 2 mm. Water was added to the selected sample sites. Samples were placed on a 50°C heated plate to record thermal images and thermal images combined with visual contours of samples with simulated defects. Area Calculator – SketchAndCalc Icalc, Inc. was used to describe the size and location of the defects. Findings: As a result of the tests, the use of the Flir One thermal imaging device in epoxycarbon composite discontinuity tests has been demonstrated, and a methodology has been proposed to measure geometrical features of defects. Research limitations/implications: The description of welded joint structure and mechanical properties was based on welding toughened steels by using an innovative welding method and a filler that has been proposed. Practical implications: The development of thermal imaging studies of polymer composite discontinuity using the Flir One thermal imaging camera and accessory with iOS opens up the possibility of conducting a basic inspection of composite materials in production plants, and even for simplicity – also in small laboratories. Originality/value: In order to improve the quality of imaging of small items using the Flir One mobile camera, the use of cheap and readily available lenses used in laser optics has been tested positively.

2015 ◽  
Vol 220-221 ◽  
pp. 859-863 ◽  
Jordan Mężyk ◽  
Szymon Kowieski

Friction stir welding (FSW) is a recently developed method for making a rigid joint of materials that are otherwise hard to weld. It uses a rotating tool for softening the materials without reaching the melting point, and while the tool is moved along the joint line the plasticised material from the joined materials is mixed and hardened producing the solid phase bond. The article presents the authors’ method for monitoring the Friction Stir Welding (FSW) processes with use of thermal imaging camera.FSW method is a new method and there are only few tools to assess the quality of the process, especially on-line, that is in the making of the weld. The authors propose a method for monitoring the FSW process using hybrid vision methods that is acquisition of the image of the weld with the use of a thermal imaging camera and visual band camera. The paper presents selected results of research performed using infrared imaging channel.The recorded thermograms allow identifying the weld defects and non-compliances during the process and using a thermal imaging camera, also allow detecting subsurface defects. The obtained results indicate its potential practical application but still the described application is to be further developed to become a part of a hybrid system for monitoring the FSW processes.

Mustafa Qays Hatem ◽  
Ahmed Aizaldeen Abdullah

In this paper, the Voice over Internet Protocol (VoIP) was analyzed, and the performance of the quality of service (QoS) parameters obtained through the OPNET simulation software was evaluated. The case study started with the analysis of the network structure .It examined the optimal planning parameters and considered to optimize the performance of the Worldwide Interoperability for Microwave Access network to increase the VoIP service performance. The simulation covered three scenarios with different configurations; each scenario was elevated in term of QoS. The simulations studied various cases including variation in cell radius, different number of users, and different number of cells. Results showed that increasing the cell radius does not increase the quality of the network, and increasing the number of users inside one cell also degrades the quality of the network. By contrast, distributing users into different cells increasesthe network performance but enhances the delay time and increases the throughput.

2021 ◽  
Vol 58 (2) ◽  
pp. 92-118
Maciej Zawistowski

Aim: The article presents a set of parameters and settings for unmanned aerial vehicles (UAV), which is crucial in the operational work of the fire brigade and its importance for the quality of the final material obtained from an RGB camera or a thermal imaging camera. Introduction: Unmanned aerial vehicles (UAVs) are more often and more boldly used by various uniformed formations, including pilots of the State Fire Service and Volunteer Fire Brigades. Currently, they are used to perform recognition of situations and coordination of activities with the use of RGB and thermal imaging cameras. There are also other applications of UAV, including firefighting, but at the moment they are only conceptual solutions, as they have not been tested during an actual firefighting operation. According to the authors, a drone is currently only a carrier of additional devices and its functionality during the operation depends largely on certainty and reliability of a given UAV structure, as well as on the type and quality of the elements and sensors mounted on it. Methodology: A review of literature and press reports, as well as the authors’ experience in working with UAVs and the results of their research were used to analyse the topic. Conclusions: Indicating a set of key parameters for the UAVs used by fire brigade users is only possible to define its application. Therefore, in this study, the authors presented the most common use of unmanned aerial vehicles, for which key parameters were indicated and the impact of these factors on the obtained results of drones was described. Due to the frequent neglect of camera operation and the importance of their parameters, the authors described the most frequently set parameters of photographs and their impact on the final result, which is of key importance for the usefulness of the collected material.

2018 ◽  
Vol 49 ◽  
pp. 00118
Daniel Tokarski ◽  
Tomasz Grudniewski ◽  
Marta Chodyka ◽  
Jerzy Antoni Nitychoruk

The article aims to present the issue of excessive heat release at installation joints due to insufficient contact surface of the joining elements. The conducted research attempts to estimate the losses caused by an insufficient contact surface area. A laser pyrometer and a thermal imaging camera were used to perform the tests. Both devices generate images without having to touch the tested element, which may indicate that the obtained results are very accurate. The completed tests have shown that an insufficient contact surface of the joints results in an increased heat release, which leads to higher electrical energy losses and increased wear of the installation connectors.

2020 ◽  
Fernanda Silva Moreira ◽  
Rafaela Fujita Lima ◽  
Luis Felipe Cândido ◽  
João Carlos Gonçalves Lanzinha

The development of studies about the housing constructions developments came from the need to ratify the effectiveness of the construction systems to the detriment of the low quality of the final product related to civil construction, which was unfolded in the creation of ABNT NBR 15,575 / 2013 - Housing Constructions - Performance. However, its implementation is still a point of discussion among several companies in this field, besides there is a gap between the requirements and established criteria and the adequacy of the constructive practices. Thus, the present work aims to analyse, through a multiple case study, the process of implementation of the Standard Performance in Brazilian construction companies, focusing on the main difficulties of implementation. For that, semi-structured interviews were carried out in 5 constructors, being possible to identify the implementation process adopted by each company and its main difficulties of adequacy to the norm. Thus, it was possible to verify that although the standard performance is required, the increase in costs resulting from this requirement has delayed its implementation, being the main difficulty of adequacy. In addition, it was observed that although the implementation process of the regulations is incipient, any effort in its direction represents an improvement in the quality of the civil construction and, consequently, in the durability and useful life of the buildings.

2020 ◽  
Vol 29 (4) ◽  
pp. 685-690
C. S. Vanaja ◽  
Miriam Soni Abigail

Purpose Misophonia is a sound tolerance disorder condition in certain sounds that trigger intense emotional or physiological responses. While some persons may experience misophonia, a few patients suffer from misophonia. However, there is a dearth of literature on audiological assessment and management of persons with misophonia. The purpose of this report is to discuss the assessment of misophonia and highlight the management option that helped a patient with misophonia. Method A case study of a 26-year-old woman with the complaint of decreased tolerance to specific sounds affecting quality of life is reported. Audiological assessment differentiated misophonia from hyperacusis. Management included retraining counseling as well as desensitization and habituation therapy based on the principles described by P. J. Jastreboff and Jastreboff (2014). A misophonia questionnaire was administered at regular intervals to monitor the effectiveness of therapy. Results A detailed case history and audiological evaluations including pure-tone audiogram and Johnson Hyperacusis Index revealed the presence of misophonia. The patient benefitted from intervention, and the scores of the misophonia questionnaire indicated a decrease in the severity of the problem. Conclusions It is important to differentially diagnose misophonia and hyperacusis in persons with sound tolerance disorders. Retraining counseling as well as desensitization and habituation therapy can help patients who suffer from misophonia.

2017 ◽  
Vol 2 (3) ◽  
pp. 57-62
Anna Maria Siciliano

This paper presents a successful behavioral case study in treatment of chronic refractory cough in a 60-year-old adult female. The efficacy for speech-language pathology treating chronic cough is discussed along with description of treatment regime. Discussion focuses on therapy approaches used and the patient's report of changes in quality of life and frequency, duration, and severity reduction of her cough after treatment.

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