scholarly journals Temperature distribution analysis of different technologies of PV modules using infrared thermography

2018 ◽  
Vol 49 ◽  
pp. 00044 ◽  
Author(s):  
Slawomir Gulkowski ◽  
Natalia Zytkowska ◽  
Piotr Dragan

Photovoltaic systems are designed to operate for a very long time according to the modules’ warranty that guarantees at least of 80% of the nominal power production after 20 years of use. In order to assure the continuous power production with a high level for a long time, thermographic analysis should be performed to detect incipient anomalies in individual modules and junction boxes. This safe, convenient and noncontact method allows carrying out the inspection for working system without any contact with live wiring and without disconnecting the PV systems. Temperature distribution of the module surface can reveal many different types of anomalies, i.e. hot spots caused by local shading, microcracking or cell breakage. This paper shows the results of the infrared thermography analysis of the operating PV systems consisting of different technological modules: polycrystalline silicon (pc-Si), copper indium gallium diselenide (CIGS) and cadmium telluride (CdTe). The average working temperature of each different kind of technological module as well as overheated areas were investigated in this study. Temperature of the MC4 connectors was also analysed.

2007 ◽  
pp. 106-107
Author(s):  
B. K. Gannibal

Leonid Efimovich Rodin (1907-1990) was a graduate of Leningrad state University. To him, the future is known geobotanica, happened to a course in Botanical geography is still at the N. A. Bush. His teachers were also A. P. Shennikov and A. A. Korchagin, who subsequently headed related Department of geobotany and Botanical geography of Leningrad state University. This was the first school scientist. And since the beginning of the 30s of XX century and until the end of life L. E. was an employee of the Department of geobotany of the Komarov Botanical Institute (RAS), where long time worked together with E. M. Lavrenko, V. B. Sochava, B. A. Tikhomirov, V. D. Alexandrova and many other high-level professionals, first continuing to learn and gain experience, then defining the direction of development of geobotany in the Institute and the country as a whole.


2020 ◽  
Vol 11 (04) ◽  
pp. 640-642
Author(s):  
Halil Onder

AbstractGait disorders are common in the elderly as there are various causes of neurological and non-neurological conditions. On the other hand, most of the gait parameters do change with advancing age which is identified as age-related physiological changes in gait. At this point, the discrimination between age-related physiological changes and gait disorders may be strictly challenging. After identifying gait as an abnormal pattern, classification of it and making the responsible pathophysiology also require high-level expertise in this regard. Herein, we present a rare patient with corticobasal degeneration (CBD) who had admitted initially due to complaints of gait problems. Over a long time, the patient had received the misdiagnosis of gait abnormality due to musculoskeletal problems by multiple physicians. However, the detailed neurological exam showed a higher level gait disorder (HLGD). Further investigations at this point yielded the diagnosis of CBD.


2005 ◽  
Vol 68 (7-8) ◽  
pp. 641-651 ◽  
Author(s):  
Valerio Lombardo ◽  
Maria Fabrizia Buongiorno ◽  
Stefania Amici

2021 ◽  
Author(s):  
Farnoos Farrokhi

The International Technology Roadmap for Silicon (ITRS) predicted that by the year 2016, a high-performance chip could dissipate as much as 300 W/cm² of heat. Another more noticeable thermal issue in IC's is the uneven temperature distribution. Increased power dissipation and greater temperature variation highlight the need for electrothermal analysis of electronic components. The goal of this research is to develop an experimental infrared measurement technique for the thermal and electrothermal analysis of electronic circuits. The objective of the electrothermal analysis is to represent the behavior of the temperature dependent characteristics of electronic device in near real work condition. An infrared (IR) thermography setup to perform the temperature distribution analysis and power dissipation measurement of the device under test is proposed in this reasearch. The system is based on a transparent oil heatsink which captures the thermal profile and run-time power dissipation from the device under test with a very fine degree of granularity. The proposed setup is used to perform the thermal analysis and power measurement of an Intel Dual Core E2180 processor. The power dissipation of the processor is obtained by calculating and measuring the heat transfer coefficient of the oil heatsink. Moreover, the power consumption of the processor is measured by isolating the current used by the CPU at run time. A three-dimensional fininte element thermal model is developed to simulate the thermal properties of the processor. The results obtained using this simulation is compared to the experimental results from IR thermography. A methodology to perform electrothermal analysis on integrated circuits is introduced. This method is based on coupling a standard electrical simulator, which is often used in the design process, and IR thermography system through an efficient interface program. The proposed method is capable of updating the temperature dependent parameters of device in near real time. The proposed method is applied to perform electrothermal analysis of a power MOSFET to measure the temperature distribution and the device performance. The DC characteristics of the device are investigated. The obtained results indicated that the operating point, I-V characteristics and power dissipation of the MOSFET vary significantly with temperature.


2019 ◽  
Vol 4 (2) ◽  
pp. 89-101
Author(s):  
Samfriati S ◽  
Lilis N ◽  
Mercy N G

Academic procrastination is one of the postponement behaviors in lecture activities that are often found in students, in this study respondents experiencees a high level of procrastination that could hamper academic activities. One of the causes of procrastination is the use of gadgets that are too long to play games, music, entertainment and so on. Goals : The purpose of this study is to find out the relationship between the use of gadgets and academic procrastination onNursing Students level II Saint Elisabeth Medan 2019. Method : The study design is Cross Sectional. Total sampling technique sample are112 students. The measuring instrument used is a questionnaire. Result : The results shows that the majority of use of positive gadgets (92.9%) and moderate academic procrastination (63.4%). Based on the Fisher's Exact Test, it obtained p-value 0.026 (p <0.05), thus indicating a relationship between the use of gadgets and academic procrastination on nursing students level II STIKes Saint Elisabeth Medan. Conculsion: It is expected that respondents will be able to manage time well and not use gadgets for a long time for things that are not useful. Respondent s are expected to use gadgets for things that can support learning activities.


Author(s):  
Matiashuk R. ◽  
Tkachenko I.

The sensitivity of the reproductive structures of Forsythiasuspensato the complex influence of undifferentiated environmental factors has been studied.The monitoring sites are located in 15 different park ecosystems in 6 administrative districts of Kyiv. Data from the Borys Sreznevsky Central Geophysical Observatory (air pollution index (API) and meteorological conditions for 2018-2020) were used to assess the conditions of the growthenvironment. The influence of a complex of ecologically important factors during the flowering offorsythia on the quality of the formedpollen is noted. Thus, growing plantsfor a long time in conditions with a low level of air pollution (APIup to 5.0) in abnormal weather conditions in 2020,40-50% less fertile grainswere formed. And forplants, which grow in areas with increasedlevel (API5.0-7.0) and high level (API7.0-14.0) of air pollution, the share of fertile grains in the pollen population decreased by 60-80%. In the closed bud,the pollen has higher resistance to a complex of exogenous growth factors. Forsythia plants, which are located in large parklands, lose less pollen quality in adverse weather conditions and affected byurbotechnogenic factors. F. suspensa is an acceptable indicator of the level of environmental pollution by the deviation of pollen fertility from the control value. In areas with high aerogenic load, for example, areas with large highways (Bus Station «Darnytsia»), as well as with a significant recreational load (HolosiivskyiPark, Recreation Park on the Olena Teliha Street) much smaller pollen is formed. Itis noted that the conditions of forsythia growth affect the quantitative indicators of the formed pollen not only in the flower but also in the closed bud, which confirms the chronic effect of the complex of ingredients of aerotechnogenic emissions on plants of this species. The coefficient of sterility of pollen (CS) was used to objectively compare the data of 2019 and 2020 on the condition of the generative organs of F. suspensa in the studied areas. The calculation of the CS confirmed that in the closedbud pollen has a higher resistance to exogenous factors. In areas with high and increased levels of air pollution,during budding and flowering of plants (March-May,) there is a much higher CS of pollen of F. suspensа. Significant parkland territoriesof the city (for example, HolosiivskyiPark, Botanical Garden named after O. V. Fomin) provide less stressful conditions for growth and development of plants, even with the "very high" level of air pollution (ISA above 14.0) observed in April 2020 on this territory.The study of the susceptibility of F. suspensаpollen to growing conditions will be continued, as the prospects of using this species for bioindication of ecological status and zoning of park ecosystems of Kyiv according to the gradient of anthropogenic impact have been revealed.Key words:forsythia, fertility, coefficient of sterility of pollen, bioindication. Проведене дослідження чутливості репродуктивних структур Forsythiasuspensaдо комплексного впливу недиференційованих факторів навколишнього середовища. Моніторингові ділянки розташовані в 15 різних паркових екосистемах 6 адміністративних районівКиєва. Для оцінки умов середовища вирощування рослин використані дані Центральної геофізичної обсерваторії імені Бориса Срезневського (індекс забруднення атмосферного повітря (ІЗА) та метеорологічні умови за 2018-2020 рр.). Відмічено вплив комплексу екологічно важливих факторів (за показниками відхилення від норми середньої місячної температури повітря та місячної кількості опадів у Києві) уперіод квітування форзиції на якість сформованого пилку. Так, за тривалої експозиції рослин в умовах з низьким рівнем забруднення повітря (ІЗА до 5,0) в аномальних погодних умовах 2020 р. сформувалось на 40-50% менше фертильних зерен. А у форзиції, яка росте на територіях з підвищеним (ІЗА 5,0-7,0) та високим (ІЗА 7,0-14,0) рівнями забруднення частка фертильних зерен в популяції пилку зменшилась на 60-80%. У закритому бутоні пилок має вищу стійкість до комплексу екзогенних факторів середовища зростання. Рослини форзиції, які розташовані у значних за площею паркових насадженнях, менше втрачають якість пилку за несприятливих погодних умов та дії урботехногенних чинників. За відхиленням показника фертильності пилку від контрольного значення F. suspensaє допустимим індикатором рівня забруднення середовища. На територіях з підвищеним аерогенним навантаженням, наприклад, ділянки з автотранспортними магістралями (Автостанція «Дарниця»), а також зі значним рекреаційним навантаженням (Голосіївський парк імені М. Рильського, Парк відпочинку по вул. Олени Теліги)формується значно дрібніший пилок. Відмічено, що умови росту позначаються на кількісних показниках сформованого пилку не лише в квітці, але й в закритому бутоні, що підтверджує хронічний вплив комплексу інгредієнтів аеротехногенних викидів нарослини цього виду. Для об’єктивного співставлення даних 2019 і 2020 рр. щодо стану генеративних органів F. suspensaна досліджених ділянках був використаний коефіцієнт стерильності (КС) пилку. Розрахунок КС підтвердив, що в закритому бутоні пилок має вищу стійкість до впливу екзогенних чинників. Вищий КС був у F. suspense, з ділянок, на яких в період бутонізації і квітування рослин (березень-травень) відмічений високий і підвищений рівень забруднення атмосфери. Значні за площею паркові насадження міста (наприклад, Голосіївський парк, Ботанічний сад ім.акад. О.В. Фоміна) забезпечують менш напружені умови росту і розвитку рослин навіть при відміченому в квітні 2020 р. «дуже високому» рівні забруднення повітря (ІЗА вище 14,0) на цих територіях. Дослідження чутливості пилку F. suspenseдо умов вирощування буде продовжене,оскільки виявлена перспективність використання цього виду для біоіндикації екологічного стану та зонування паркових екосистем Києва за градієнтом антропогенного впливу.Ключові слова: форзиція, фертильність, індекс стерильності, біоіндикація.


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