Estimation of the wet bulb globe temperature from temperature and relative humidity gradients

In this study, maps of the estimated heat index for a preservation area in the city of Cuiabá, Mato Grosso, Brazil, were constructed using temperature and relative humidity gradients. Understanding microclimate variable behavior is useful for explaining the relationship between urban sprawl and increased environmental distress. The implementation and preservation of green areas is one way to mitigate the environmental impacts of human activities. Urban parks are one common type of green area in cities. According to ISO 7243, heat exposure can be assessed using the Wet Bulb Globe Temperature (WBGT). This study used multivariate statistical techniques and ordinary kriging to produce a WBGT map of the park during the dry and rainy seasons. Places with heat or freshness islands were identified. Locations along hiking trails and areas with exercise equipment were analyzed for WBGT tendencies in order to propose precautionary heat exposure measures

Polybrominated diphenyl ethers (PBDE) as persistent contaminants : origin, behavior in the environment and analytical strategies

Flame retardants are substances mixed with numerous materials to inhibit the combustion process, reducing risks and damages caused by fires. Among these substances, polybrominated diphenyl ethers (PBDEs) have been widely used for decades due to their low cost and high efficiency. However, since they are mixed and not chemically bonded to the materials, PBDEs can be released over time being transported through numerous pathways until they reach soils and aquatic systems, where they can accumulate in sediments and biota. Due to their high chemical stability, an essential feature for flame retardants, they are considered persistent contaminants. Several studies report the presence of PBDEs in atmospheric and aquatic particulate matter, sediments, soils and biological matrices such as marine animals, tissues and human fluids. In Brazil, little is known about the use and commercialization of PBDEs, as well as their levels in different environmental compartments. Thus, this review provides an overview of the origin of PBDEs in the environment as well as information inherent to the understanding of the behavior and presence of this contaminants of recent interest in different environmental compartments. Finally, the manuscript also brings state-of-the-art analytical approaches used for environmental sampling, preservation, preparation and sample analysis

Interceptação da luz pelo cajueiro

A interceptação da luz pelas plantas pode ser utilizada na simulação de vários processos ecofisiológicos que influenciam a produtividade e a qualidade de frutos, tornando-se fator estratégico no manejo de plantas no pomar. Objetivou-se, neste trabalho, avaliar o modelo de Charles-Edward & Thornley de interceptação da luz em plantas isoladas de cajueiro anão. O trabalho foi realizado na fazenda experimental da Universidade Federal de Mato Grosso, no período de 03/09/2012 a 09/11/2012. A simulação da luz interceptada foi efetuada em intervalos de 60, 120, 180, 240 e 300 min. A interceptação variou entre as plantas e entre as escalas temporais adotadas. Em escala de 60 min os dados simulados apresentaram tendência de subestimar valores de radiação medida com sensores pontuais no início e no final do dia, independente da planta utilizada. Na escala de 300 min, por sua vez, a simulação foi a mais próxima do valor medido com sensores pontuais, com R²: 0,90; d: 0,96; c: 0,91 e EAMP 5,65