scholarly journals Campo Térmico Urbano e a sua Relação com o Uso e Cobertura do Solo em Cidade Tropical Úmida (Thermal Urban Field and its Relation to the Use and Land Cover in a Humid Tropical City)

2012 ◽  
Vol 5 (3) ◽  
pp. 540 ◽  
Author(s):  
Joel Silva dos Santos ◽  
Vicente De Paulo Rodrigues da Silva ◽  
Eduardo Rodrigues Viana Lima ◽  
Lincoln Eloi de Araújo ◽  
Angelina Dias Leão Costa
Keyword(s):  
Relative Humidity ◽  
Land Cover ◽  
Thermal Comfort ◽  
Quantitative Methods ◽  
Urban Climate ◽  
Temporal Trends ◽  
Vegetation Coverage ◽  
Heat Island ◽  
Tropical Regions ◽  
Discomfort Index

As alterações ocorridas no sistema climático urbano das grandes cidades são processos relacionados ao adensamento urbano e às diferentes formas de uso e cobertura do solo. O objetivo deste trabalho foi analisar o campo térmico urbano e a sua relação com as diversas formas de uso e cobertura do solo em cidade tropical úmida, especificamente a cidade de João Pessoa, PB. As medições da temperatura do ar e umidade relativa foram realizadas em dois períodos distintos de três meses (seco e chuvoso), utilizando-se termo-higrômetro da marca Hobos em nove pontos representativos da malha urbana de cidade.  O nível de estresse térmico foi avaliado com base no índice de desconforto de Thom (IDT) para regiões tropicais, ajustado através de questionários de avaliação da sensação térmica das pessoas nos pontos monitorados. O teste de Mann-Kendall foi utilizado para avaliar a tendência temporal das séries climatológicas de temperatura, umidade relativa do ar e do IDT no período de 1963 a 2011. Os tipos de cobertura de solo de cada ponto monitorado foram classificados dentro de nove classes de acordo com a percentagem de vegetação e de materiais permeáveis e impermeáveis utilizando métodos quantitativos e qualitativos. Os resultados do trabalho indicam que a faixa de classificação do índice de desconforto de Thom não é apropriada para regiões tropicais úmidas. A ilha de calor urbano é um fenômeno que ocorre preferencialmente durante o período noturno enquanto a intensidade máxima dos gradientes de temperatura e umidade relativa do ar são fenômenos essencialmente diurnos. Os cenários dos níveis de conforto térmico indicam condições de forte desconforto ambiental para os anos de 2050 e 2060 durante o período seco e desconfortável para o período chuvoso no ano de 2060 em toda área de estudo.Palavras chaves: clima urbano, conforto térmico, ilha de calor, gradiente de temperatura. Thermal Urban Field and its Relation to the Use and Land Cover in a Humid Tropical City ABSTRACTThe changes in the urban climate system in great cities are processes related to urban density and the different forms of use and land cover. The objective of this study was to analyze the thermal urban field and its relation to the various forms of use and land cover in a humid tropical city, specifically Joao Pessoa city, PB, Brazil. Measurements in air temperature and relative humidity were carried out in two distinct periods of three months (dry and wet seasons), using thermo-hygrometer Hobos located in nine representative areas of the city. The level of heat stress was evaluated based on Thom's discomfort index (IDT, in Portuguese), adjusted for tropical regions based on questionnaires for assessing the thermal sensation that people have in function to the parameters that determine the environment in which they live. Mann-Kendall test was used to assess the temporal trends of time series in temperature, relative humidity and IDT for the period from 1963 to 2011. The types of ground cover of each monitored point were classified into nine classes according to the percentage of vegetation coverage and permeable and impermeable materials by utilizing both qualitative and quantitative methods. The results of the study indicated that the classification range of the Thom’s discomfort index is not suitable for humid tropical regions. The urban heat island is a phenomenon that occurs preferentially during the night while the maximum intensity of the temperature and relative humidity gradients are essentially diurnal phenomena. The scenarios of the thermal comfort levels indicated a strong discomfort for the 2050 and 2060 years during the dry season and uncomfortable condition during the rainy season in the 2060 year throughout the study area.Keywords: urban climate, thermal comfort, heat island, temperature gradient.

scholarly journals Microclima e a arborização: o caso de duas áreas do Núcleo Marabá Pioneira, Marabá - Pará

2016 ◽  
Vol 4 (2) ◽  
pp. 54
Author(s):  
Antônio Pereira Júnior ◽  
Edmir Dos Santos Jesus ◽  
Milka Beatriz Faval Bastos ◽  
Rafael Victor Castro Santos
Keyword(s):  
Quality Of Life ◽  
Relative Humidity ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Sensation ◽  
Urban Climate ◽  
Air Humidity ◽  
Discomfort Index ◽  
Opposite Tendency

Studies of the urban climate involve numerous climatic variables, such as temperature, air humidity and vegetation. The objective of this research was to determine the trend of two meteorological variables (air temperature relative humidity), in relation to the arborization, sensation and thermal hygrometric perception of the population in the microclimate of two areas (A1 = Avenue Antônio Maia; A2 = Street 5 de Abril) Core Marabá Pioneira. For the measurement of temperature and humidity of the air, the methodology recommended by the Agronomic Institute of Campinas (IAC), adapted for the schedules and collection numbers, was applied. To obtain data on thermal comfort, seventy mixed forms were applied for two consecutive days at 12 hours. The thermal sensation was classified per the contained in the Predicted Mean Vote (PMV) and the discomfort, with the Thom Discomfort Index (ID). Twelve daily readings (6:00 a.m. to 5:00 p.m.) were carried out at each hour in the four meteorological shelters (two in each area) during 23 days of July 2015. The results indicated that the air temperature has tendencies to elevation, The relative humidity of the air, presents opposite tendency. The thermal sensation is very hot (+3), the satisfaction with shading was classified as good (A2 = 50%) and regular (A1 = 41.67%), thermal comfort (A1 = 28.76 °C; A2 = 27.70 ºC), ranges from uncomfortable to very uncomfortable. Therefore, there is a need to improve afforestation in the Marabá Pioneira Nucleus, in order to reduce the discomfort index and the quality of life of the population.

scholarly journals ANÁLISE DO CONFORTO TÉRMICO HUMANO NO MUNICÍPIO DE ARAPIRACA – ALAGOAS, UTILIZANDO SOFTWARE MATLAB (ANALYSIS OF THE HUMAN THERMAL COMFORT THE CITY OF ARAPIRACA - ALAGOAS USING SOFTWARE MATLAB)

2015 ◽  
Vol 7 (5) ◽  
pp. 939
Author(s):  
Juliete Baraúna dos Santos
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Effective Temperature ◽  
Rainy Season ◽  
Prolonged Exposure ◽  
Urban Climate ◽  
Heat Stroke ◽  
Human Thermal Comfort ◽  
Discomfort Index ◽  
The City

Foram obtidas medidas das variáveis meteorológicas temperatura do ar, umidade relativa do ar e velocidade do vento através da estação automática instalada em Arapiraca com a finalidade de monitorar as condições de tempo no município em diferentes períodos (época chuvosa e seca). Sendo utilizado o índice de desconforto (ID), o índice de desconforto de Kawamura (IDK), índice da temperatura efetiva (TE) e o índice de temperatura efetiva em função do vento (TEV). Os valores mais elevados dos índices que foram registrados para o período chuvoso, foram do índice id com aproximadamente 2,5 °C acima dos valores observados da temperatura do ar (em média 26,5 °C), caracterizando crescente desconforto para os indivíduos locais.  Para o período seco não houve registros de grandes variações entre os respectivos índices. E assim como no período chuvoso, os valores mais elevados no período seco foram do índice id, indicando nesse período também forte desconforto. Os valores obtidos estiveram condizentes com a literatura, sendo a sensação térmica mais preponderante durante o inverno. E, de acordo com as variações, em todo período de estudo (05 de maio de 2008 a 05 de maio de 2011) a população foi submetida aos alertas de atenção e muito cuidado, situação esta que pôde provocar fadiga ou cãibras, esgotamento e insolação nos casos de exposição prolongada e atividade física.      A B S T R A C T Measurements of meteorological variables air temperature, relative humidity and wind speed by automatic station installed in Arapiraca in order to monitor the weather conditions in the city in different periods (dry and rainy season) were obtained. Being used the discomfort index (ID), the discomfort index of Kawamura (IDK), index of effective temperature (TE) and the index of effective temperature as a function of wind (TEv). Higher index values ​​that were recorded for the rainy season, the index id were approximately 2.5 ° C above the observed values ​​of air temperature (average 26.5 ° C), indicating increasing discomfort for local individuals . For the dry period there were no reports of large variations between the respective indices. And just as the rainy season, the highest values ​​in the dry season were the index id, indicating that period also strong discomfort. The values ​​obtained were consistent with the literature, the most predominant wind chill during the winter. And, according to the variations in the study period (May 5, 2008 to 05 maio 2011) the population was subjected to warnings of attention and care, a situation that could cause fatigue or cramps, exhaustion and heat stroke in cases of prolonged exposure and physical activity.   Key-Words: Urban climate. Thermal comfort Human. Bioclimatic

scholarly journals Emerging hot Spot Analysis and the Spatial-temporal Trends of NDVI in the Jing River Basin of China

2021 ◽  
Author(s):  
Bin Xu ◽  
Bin Qi ◽  
Kai Ji ◽  
Zhao Liu ◽  
Lin Deng ◽  
...  
Keyword(s):  
Land Cover ◽  
River Basin ◽  
Water Conservation ◽  
Hot Spot ◽  
Temporal Trends ◽  
Soil And Water Conservation ◽  
Vegetation Coverage ◽  
Cold Spot ◽  
The Loess Plateau ◽  
Soil And Water

Abstract As an important indicator of vegetation coverage, the Normalized Difference Vegetation Index (NDVI) reflects the changing pattern and evolving trend of the environment. In the Loess Plateau, vegetation plays a critical role in soil and water conservation, which strongly affects the achievement of sustainable development goals. The study of the spatial distribution and temporal trends of NDVI is of great practical importance for the planning of soil and water conservation measures, the evaluation of environmental situation. In this study, the NDVI, precipitation and land cover data of the Jing River Basin were collected, the emerging hot spot and cold spot patterns of NDVI were examined, the characteristics of spatial distribution and temporal variation of the NDVI in the basin were analyzed, the impacts on NDVI changes from climate, land cover change have been discussed. The results show that the NDVI in Jing River Basin shows a spatial trend of decreasing from northwest to southeast. The emerging hot spot analysis results show that diminishing cold spot, oscillating hot spot, intensifying hot spot are predominant patterns in the basin. The whole basin shows the statistically significant upward trend of high-value aggregation of NDVI. The temporal trend of NDVI in the basin varies from-0.0171 to 0.0185 per year. The increasing trend of vegetation coverage in the basin is statistically significant. The positive correlation between the NDVI and the precipitation mainly observed upstream of the basin, revealing that the growth of vegetation in the Loess Plateau is more dependent on the water supply from the precipitation. Land cover transition patterns and the land use patterns also impact the spatial-temporal trends of the vegetation coverage in the basin. The study results may helpful for the vegetation restoration, soil and water conservation and sustainable development of the Jing River Basin.

scholarly journals Análise de Microclimas na Cidade de Viçosa do Ceará: Abordagem na Perspectiva do Conforto Térmico (Analysis of the Microclimate in Viçosa Ceará: Approach in View of Thermal Comfort)

2012 ◽  
Vol 5 (1) ◽  
pp. 47 ◽  
Author(s):  
Filipe Da Silva Peixoto ◽  
Marta Celina Linhares Sales
Keyword(s):  
Thermal Comfort ◽  
Effective Temperature ◽  
Urban Climate ◽  
City Centre ◽  
Heat Island ◽  
Humid Climate ◽  
Heat Islands ◽  
Environmental Features ◽  
Different Types ◽  
The City

O estudo foi realizado na cidade de Viçosa do Ceará, cujas características geoambientais proporcionam um tipo climático de enclave úmido, ou seja, resulta em uma área de maior umidade e menor temperatura média isso devido ao efeito da altitude, em meio às áreas mais rebaixadas que configuram a depressão sertaneja, portanto, são áreas de condições geoambientais mais favoráveis ao conforto térmico. Buscou-se nos pontos de análise a distinção de diferentes tipos de uso e ocupação do solo, associado às características naturais que causam diferentes microclimas intraurbanos. Esses foram analisados através do levantamento de dados de temperatura do ar, temperatura efetiva, umidade do ar, e altitude. O levantamento foi realizado entre às 08 e 17 horas no dia 29 de outubro de 2009, período de primavera no hemisfério sul, correspondente ao período quente e seco no nordeste setentrional.  Os dados foram tratados de forma a evidenciar os diferentes microclimas qualitativa e espacialmente, através de gráficos comparativos e mapa de isolinhas de temperatura efetiva. Foi observado que sob o efeito das ilhas de calor, identificadas nos pontos dois (Centro da Cidade) e três (Praça do Coreto), a atmosfera do local se comporta de maneiras distintas, e esses pontos caracterizaram-se pela conservação de temperatura efetiva de 26 ºC às 15 horas, quando em condições normais essa temperatura tenderia a um decréscimo maior, situação observada nos demais pontos ambos com 24,8 ºC às 15 horas. A atmosfera da cidade de Viçosa do Ceará sofre o fenômeno da ilha de calor, que se mostra no espaço onde o uso e ocupação do solo são mais intensificados.   Palavras- chaves: Clima urbano. Viçosa do Ceará. Espaço Urbano.   Analysis of the Microclimate in Viçosa Ceará: Approach in View of Thermal Comfort   ABSTRACTThe study was conducted in Viçosa do Ceará, whose geo-environmental features provide a kind of enclave humid climate, which in the state of Ceará is configured as an area of ​​geo-environmental conditions more favorable for thermal comfort. Sought on the points of analysis to distinguish different types of land use and land cover, associated with natural features that cause different microclimates in space city. These were analyzed using the survey data of air temperature, actual temperature, humidity, and altitude. The survey was conducted between at 08 and 17 hours on October 29, 2009, the data were treated to highlight the qualitatively different microclimates and spatially, through graphs and comparative map of isolines of effective temperature. We note that under the effect of heat islands, identified in section 2 (City Centre) and 3 (Square Bandstand), the atmosphere of the site behaves differently, and these points were characterized by the conservation of effective temperature of 26 C for 15 hours, when this temperature under normal conditions would tend to a larger decrease observed in the other two points to 24.8 º C at 15 hours. The atmosphere of the city of Viçosa do Ceará suffers the heat island phenomenon, which appears in the space where the use and occupation are more intensified. Keywords: Urban climate. Viçosa- Ce. Space Urban. 

scholarly journals Land use/land cover change and its impact on surface urban heat island and urban thermal comfort in a metropolitan city

Urban Climate ◽  
2022 ◽  
Vol 41 ◽  
pp. 101052
Author(s):  
Shahfahad ◽  
Mohd Waseem Naikoo ◽  
Abu Reza Md. Towfiqul Islam ◽  
Javed Mallick ◽  
Atiqur Rahman
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Thermal Comfort ◽  
Urban Heat Island ◽  
Land Cover Change ◽  
Heat Island ◽  
Land Use Land Cover ◽  
Metropolitan City ◽  
Urban Heat ◽  
Surface Urban Heat Island

scholarly journals Índices de (des) conforto humano em um município de clima semiárido

2020 ◽  
Vol 13 (07) ◽  
pp. 3287
Author(s):  
Rebecca Luna Lucena ◽  
Jório Bezerra Cabral Júnior ◽  
Ercília Torres Steinke
Keyword(s):  
Thermal Comfort ◽  
Urban Climate ◽  
Heat Island ◽  
Temperature Index ◽  
Human Thermal Comfort ◽  
Data Loggers ◽  
De Se ◽  
Humidity Index ◽  
Semi Arid ◽  
Comfort Indices

O objetivo principal neste trabalho consistiu em analisar e comparar índices de (des) conforto térmico humano em um município de clima semiárido. Para isso foram adquiridos e utilizados equipamentos termo-higrômetros automáticos datalogger Akso AK170, sendo esses distribuídos espacialmente em onze pontos (dez em áreas urbanizadas e um em área rural), durante um período de 32 dias, em Caicó-RN. De posse dos dados horários de temperatura e umidade relativa do ar (maio/junho), realizaram-se análises estatísticas descritivas e aplicaram-se três índices de conforto humano, a saber: Índice de Desconforto (ID), índice de Temperatura Efetiva (TE), e o Índice de Temperatura e Umidade (ITU). Os resultados indicaram que o município de Caicó está propenso aos efeitos do processo de urbanização, registrando-se frequências de temperaturas mais elevadas nas áreas urbanizadas, especialmente nas de menor arborização e maior concentração de pavimentos urbanos. Em termos médios a maior parte da população de Caicó sente desconforto devido ao calor (ID), as temperaturas ficaram sempre acima do considerado calor moderado (TE) e de acordo com o ITU a classificação foi de extremamente desconfortável. Portanto, é imprescindível minimizar o os efeitos da ilha de calor no município a fim de se obter melhores índices de conforto térmico humano. Human (dis) comfort indices in a semi-arid municipality in Brazil A B S T R A C TThe main aim of this study was to analyse and compare the human thermal (dis)comfort indices in a Brazilian municipality with a semi-arid climate: Caicó, in the state of Rio Grande do Norte. Akso AK170 thermo-hygrometer data loggers were acquired for this purpose, which were distributed at eleven points in the study area – ten in built-up areas and one in a rural area – over a 32-day period covering the months of May to June. Having collected the time- and date-stamped temperature and relative humidity data, descriptive statistical analyses were conducted using three human comfort indices: discomfort index (DI), effective temperature index (ETI), and temperature-humidity index (THI). The results indicate that the municipality under study is affected by urbanization processes that propitiate higher temperatures in the built-up areas, especially where there are fewer trees and more of the roads are paved. On average, most of the population of Caicó feels discomfort because of the heat (ID), and the temperature always remains above the range rated as moderately hot (ETI). The municipal climate was classified as “extremely uncomfortable” by the THI. It is therefore of the utmost importance to minimize the effects of the heat island in the municipality to improve the human thermal comfort indices.Keywords: Urban climate. Caicó-RN. Human thermal comfort indices.

scholarly journals Aplicação de Sensoriamento Remoto para a Identificação das Ilhas de Calor Urbanas e Avaliação do Conforto Térmico Humano nas Capitais dos Estados do Sul do Brasil

2020 ◽  
Vol 13 (07) ◽  
pp. 3518
Author(s):  
Jessica Israele De Medeiros ◽  
Claudia Guimarães Camargo Campos ◽  
Rodrigo Morche De Jesus
Keyword(s):  
Remote Sensing ◽  
Thermal Sensation ◽  
Urban Climate ◽  
Surface Heat ◽  
Urban Surface ◽  
Heat Island ◽  
Porto Alegre ◽  
Heat Islands ◽  
Historical Series ◽  
Discomfort Index

Os constantes processos de substituição de áreas verdes por áreas impermeabilizadas e edificadas tendem a modificar as temperaturas locais e alterar os microclimas. Como consequência, pode-se observar a ocorrência do fenômeno Ilhas de Calor (IC). O objetivo deste trabalho foi identificar a presença de ilhas de calor e avaliar o grau de desconforto térmico nas capitais dos estados da região sul do Brasil: Curitiba (PR), Santa Catarina (SC) e Rio Grande do Sul (RS). Utilizou-se imagens de sensoriamento remoto, dos satélites Landsat 5 e 8, como ferramenta para evidenciar tal fenômeno. Com base em ferramentas do geoprocessamento foi possível congregar camadas de informações, tais como: um mapeamento da ocupação urbana, da Temperatura da Superfície e da sensação térmica através do Índice de Desconforto de Kawamura. Curitiba apresentou uma melhor representatividade da urbanização e do aumento das IC, sendo que a maioria da sua extensão foi classificada como estresse devido ao calor. Florianópolis teve uma maior dimensão que foi classificada como confortável; com estresse e desconforto nas áreas mais circundantes, que correspondem aos locais mais frequentados pela população. Em Porto Alegre, na região que fica mais ao sul, houve um aumento na urbanização e uma redução nas áreas classificadas como confortáveis, principalmente nos quatro últimos anos analisados. Constatou-se que o sensoriamento remoto é uma importante fonte de dados e contribui para uma análise do clima urbano. Contudo, para uma melhor avaliação da evolução é recomendado uma ampliação da série histórica. Desta forma, ressalta-se que estudos como esse devem ser realizados também em outras regiões e municípios, para servir de subsídio para um melhor planejamento e para a adoção de diretrizes como planos de arborização. Application of remote sensing for the identification of urban surface heat islands and the Kawamura discomfort index in the capitals of the southern states of BrazilA B S T R A C TThe constant replacement processes of green areas by waterproofed and built-up areas tend to modify local temperatures and alter microclimates. Consequently, the Urban Heat Island phenomenon (UHI) can be observed. The objective of this study was to identify the presence of urban surface heat islands and evaluate the degree of thermal discomfort in the capitals of the states of the southern region of Brazil. Remote sensing images, from Landsat 5 and 8 satellites, from summer and spring thermal stations and representative years from the 1980s, 1990s, 2000s and 2010s, were used as a tool to highlight this phenomenon. Based on geoprocessing tools, it was possible to gather layers of information, such as: a mapping of urban occupation, surface temperature and thermal sensation through the Kawamura Discomfort Index. In Curitiba, the relationship between increased urbanization and UHI had been well represented over time, with the majority of its extension being classified as heat stress. In Florianópolis, the comfortable class was predominant, with stress and discomfort in the mainland and sectors to the north and south of the island. In the south region of Porto Alegre, there was an increase in urbanization and a decrease in areas classified as comfortable. However, for a better evaluation of the evolution, an expansion of the historical series is recommended. Thus, it is emphasized that studies like this should be carried out in other regions and municipalities, to serve as a subsidy for better urban planning.Keywords: bioclimatology, geotechnology, urban climate, heat island, remote sensing.

Influence of trees on the energy consumption of a social housing in mid-western Brazil

2019 ◽  
pp. 53-65
Author(s):  
Renata Domingos ◽  
Emeli Guarda ◽  
Elaise Gabriel ◽  
João Sanches
Keyword(s):  
Energy Consumption ◽  
Solar Radiation ◽  
Thermal Comfort ◽  
Air Conditioning ◽  
Computational Simulation ◽  
Building Energy ◽  
General Idea ◽  
Heat Island ◽  
Study Region ◽  
Ample Evidence

In the last decades, many studies have shown ample evidence that the existence of trees and vegetation around buildings can contribute to reduce the demand for energy by cooling and heating. The use of green areas in the urban environment as an effective strategy in reducing the cooling load of buildings has attracted much attention, though there is a lack of quantitative actions to apply the general idea to a specific building or location. Due to the large-scale construction of high buildings, large amounts of solar radiation are reflected and stored in the canyons of the streets. This causes higher air temperature and surface temperature in city areas compared to the rural environment and, consequently, deteriorates the urban heat island effect. The constant high temperatures lead to more air conditioning demand time, which results in a significant increase in building energy consumption. In general, the shade of the trees reduces the building energy demand for air conditioning, reducing solar radiation on the walls and roofs. The increase of urban green spaces has been extensively accepted as effective in mitigating the effects of heat island and reducing energy use in buildings. However, by influencing temperatures, especially extreme, it is likely that trees also affect human health, an important economic variable of interest. Since human behavior has a major influence on maintaining environmental quality, today's urban problems such as air and water pollution, floods, excessive noise, cause serious damage to the physical and mental health of the population. By minimizing these problems, vegetation (especially trees) is generally known to provide a range of ecosystem services such as rainwater reduction, air pollution mitigation, noise reduction, etc. This study focuses on the functions of temperature regulation, improvement of external thermal comfort and cooling energy reduction, so it aims to evaluate the influence of trees on the energy consumption of a house in the mid-western Brazil, located at latitude 15 ° S, in the center of South America. The methodology adopted was computer simulation, analyzing two scenarios that deal with issues such as the influence of vegetation and tree shade on the energy consumption of a building. In this way, the methodological procedures were divided into three stages: climatic contextualization of the study region; definition of a basic dwelling, of the thermophysical properties; computational simulation for quantification of energy consumption for the four facade orientations. The results show that the façades orientated to north, east and south, without the insertion of arboreal shading, obtained higher values of annual energy consumption. With the adoption of shading, the facades obtained a consumption reduction of around 7,4%. It is concluded that shading vegetation can bring significant climatic contribution to the interior of built environments and, consequently, reduction in energy consumption, promoting improvements in the thermal comfort conditions of users.

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