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This study aims to evaluate the filtration process of a commercial sand filter operating at different filtration rates and different sand particle sizes. The second objective is to carry out sand filter efficiency evaluations and compare the standard sand filter method and the proposed method. Removal efficiency was analyzed in three filtration cycles, and determined by two methodologies: counting of particles in water at the inlet and outlet of the filtration system (standard method) and in sand bed layers (proposed method). An experimental module composed of three identical commercial sand filters was used with different sand particle sizes (G1 - 0.55 mm of sand effective diameter, G2 - 0.77 mm and G3 - 1.04 mm) and filtration rate combinations (20, 40, 60, and 75 m3 m-2 h-1), repeated for three filtration cycles (C1, C2 and C3), 4 h per cycle. The removal efficiency of sand filters increases as the filtration rate increases for the water quality used, and sand particle size decreases. Between the methodologies applied to evaluate filtration systems, the method using total suspended solids retained in sand (proposed method) has shown a greater potential when compared with the standard method. The evaluation methodology proposed provides a global and accurate evaluation of the process. This form of estimation does not have the representability problem punctual water samples collected during filtration have. In addition, it is a promising methodology for farmers and technicians to carry out equipment evaluations in the field. [ABSTRACT FROM AUTHOR]

• The hydraulic architecture of rice changes along the stem, decreasing average diameters from bottom to top. • Sampling in different longitudinal positions increases precision of the estimate of hydraulic conductivity by the Hagen-Poiseuille equation. • The estimated value of hydraulic conductivity was increasing with the increase in temperature. The morphological characteristics of the xylem elements influence water ascent in the plants. Few models determine the physical process of water movement in the vascular system of plants based on the hydraulic architecture. This study aims to determine the anatomical characteristics of the xylem and potential hydraulic conductivity at different positions along the stem of rice (Oryza sativa L.). The xylem vessels characteristics were examined in four internodes using three segments in each internode. The analogy between Ohm's law and Hagen-Poiseuille was used to determine the hydraulic conductivities at three temperatures (18, 25, and 33 °C). A successive decrease in the mean vessel diameters from bottom to top stem was observed, with a significant difference between internodes. Between the Internode I and II, there was a 12% reduction in the mean diameter; between the II and III, and III and IV, the decrease was 10 and 28%, respectively. When separated into groups (left and right metaxylem), there was variation in the hydraulically weighted vessels. There was variation in the estimated value of hydraulic conductivity as a function of temperature and along the stem from the base (Internode I) to the plant's top (Internode IV). The decrease in hydraulic conductivity was 41.1 (I–II), 24 (II–III), and 73.4% (III–IV). The estimated value of hydraulic conductivity was increasing with increase in temperature. The variation of the hydraulic conductivity along the useful length of rice allowed a better application of the Hagen-Poiseuille equation. [ABSTRACT FROM AUTHOR]

The existing water scarcity in the Brazilian semiarid region, associated with anthropic activities, imply in the degradation of the watersheds present in the Caatinga. Therefore, the objective of this study was to characterize water and vegetation cover changes in the Ipanema River Watershed (IRW). IRW is inserted in municipalities that make up the dairy basins of the states of Alagoas and Pernambuco, one of the main economic activities in the Northeast of Brazil (NEB). Land use and land cover (LULC) maps, Modified Normalized Difference Water Index (MNDWI) and rainfall product via TerraClimate were used in the study. The MNDWI was based on the annual mean between 2010 and 2020 for the dry and rainy periods. For rainfall patterns and variability, pixel values were extracted and submitted to the Inverse Distance Weighted (IDW) interpolation method. We highlight the inverse relationship between the categories Forestry, Agriculture and Cattle Raising, with a decrease in the area of Caatinga due to agriculture and cattle raising. In the dry period via MNDWI there was higher water availability in 2010, 2017, 2018, 2019 and 2020, the exceptions were the years 2013–2016. In the rainy season, clouds interfered in the MNDWI analyses, with lower water availability in 2013, the exceptions were 2017 and 2018. Comparatively, the images from 2010 to 2020 via MNDWI, showed a water reduction in the IRW, mainly in the southern portion. For the dry period, the years 2011, 2012, 2016 and 2019 showed less than 138 mm of rainfall, especially in 2016 (<64 mm). In the rainy season, the years 2012, 2013, 2016, 2018 and 2019 also showed less than 482 mm of rainfall, with 2012 and 2016 standing out (<101 mm), mainly, the months with the highest rainfall record at IRW. The results obtained in this study show that droughts in the NEB continue to the present day, followed by an increase in water deficit. Anthropic action implies environmental degradation in one of the most threatened ecosystems (Caatinga), affecting mainly the water resource, an important factor in the survival of the local population and in the territorial dynamics. • Rainfall data via TerraClimate is efficient in characterizing watersheds. • MNDWI assists in characterizing the water security of river basins. • Droughts and an increase in the water deficit persist in the NEB to the present day. • Climate change is strongly impacting the NEB region. [ABSTRACT FROM AUTHOR]

The objective was to establish a model for the prediction and characterization of vaginal temperature in Holstein cows, based on environmental predictors and thermal comfort indices, through cluster analysis, validation by the cophenetic correlation coefficient, and multiple regression analysis. The micrometeorological characterization of the site was carried out by recording the air temperature (T air), the relative humidity (RH), the black globe temperature (BGT), the black globe temperature and humidity (BGHI), and dew point temperature (TDP). The recording of vaginal temperature (Tv) was performed in eight dairy cows using temperature sensors, equipped with data loggers, coupled with intravaginal devices. The data were analyzed using descriptive statistics and cluster analysis (CA) by using the hierarchical agglomerative method based on the value of the cophenetic correlation coefficient (CCC >0.70), in which representative physiological models were established, characterizing the Tv through multiple regression. In the afternoon the coefficient of variation (CV) was low for all variables, indicating homogeneity of the meteorological variables and efficiency of the ventilation system. The temperature and humidity index (THI) was mild only on the morning. There was a variation of 0.28 °C of Tv between shifts, sufficient to characterize the condition of comfort and stress of the animal, with values above 39 °C indicating animal stress. Tv showed strong correlation with BGT, T air , TDP and RH, assuming that physiological variables, such as Tv, tend to have greater relationship with abiotic variables. Empirical models were established for estimating Tv based on the analyses performed in this study. Model 1 is recommended for TDP ranges of 14.00–21.00 °C and RH of 30–100%, while model 2 can be used for T air situations up to 35 °C. The regression models for estimating Tv are promising for characterizing the thermal comfort of dairy cows housed in compost barn systems. • Cluster analysis (CA) through the cophenetic correlation coefficient (CCC) is essential. • CA by the simple linkage method is recommended for this study. • A model to characterize the vaginal temperature of dairy cows is needed. [ABSTRACT FROM AUTHOR]

Land degradation is a major challenge worldwide, limiting socio economical development and jeopardizing biodiversity, being associated to changes in land use and to climate variability. FAO shows that the world's soils have environmental degradation in large scale, particularly in semiarid areas, reducing environmental services, and impacting agriculture and livestock. Therefore, the objective was to evaluate the spatio-temporal dynamics of vegetation cover and land degradation in the microregion of Vale do Ipojuca in the Pernambuco State (Caatinga biome), in the Brazilian semiarid region, through vegetation indices. Land use and land cover maps (LULC), Normalized Difference Vegetation Index (NDVI), Leaf Area Index (LAI), and Normalized Difference Water Index (NDWI) were determined based on the annual average between the years 2014–2021. The water bodies showed remarkable reductions between 2014 and 2016, when the values were 1226, 789, and 558 ha, respectively. As observed in the NDVI, from the year 2017 onwards, the LAI values were resilient. The determination of vegetation indices associated with LULC maps and data, allowed us to accurately validate the responses of the indices studied in the semiarid region. The approach highlights the strong resilience of the Caatinga Biome. A robust methodology is presented in this study, being compatible for existing arid regions in the world. • The phenomenon of great droughts in the northeast occurs until 2019. • Soil degradation processes are evident via vegetation indices and LULC maps. • The degradation of water bodies is high in the region of this study. • The validation of TerraClimate products for the NEB is satisfactory. [ABSTRACT FROM AUTHOR]