scholarly journals Living Benthic Foraminifera from the Surface and Subsurface Sediment Layers Applied to the Environmental Characterization of the Brazilian Continental Slope (SW Atlantic)

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1863
Author(s):  
Luciana Cristina de Carvalho Santa-Rosa ◽  
Sibelle Trevisan Disaró ◽  
Violeta Totah ◽  
Silvia Watanabe ◽  
Ana Tereza Bittencourt Guimarães
Keyword(s):  
Continental Slope ◽  
Benthic Foraminifera ◽  
Subsurface Layer ◽  
Environmental Characterization ◽  
Potiguar Basin ◽  
Middle Slope ◽  
Sw Atlantic ◽  
Sediment Layers ◽  
Lower Slope

Living benthic foraminifera (>63 µm) were studied to characterize the continental slope of the Potiguar Basin (SW Atlantic). Foraminifers from the surface (0–2 cm), subsurface (2–5 cm), and integrated (0–5 cm) sediment layers were analyzed to verify their contribution to environmental characterization. It was also estimated if and which changes occur when the subsurface is added. Sampling stations were distributed in five transects in four isobaths (150, 400, 1000, and 2000 m). Sediment samples were fixed with 4% buffered formaldehyde and stained with Bengal rose. Were recorded 396 species in the surface layer, 228 in the subsurface, and 449 in integrating both layers. This study did not include tubular agglutinated species. The assemblages from 150 m isobath indicated the upper slope, from 400 m indicated the middle slope and the ones from the 2000 m indicated the lower slope. The surface layer’s assemblage at 1000 m isobath was more similar to the middle slope; in contrast, its subsurface layer´s assemblage had more similarity with the lower slope. Rarefaction curves, Permanova, and NMDS routines indicated a high resemblance between surface and integrated layers. Therefore, the first two centimeters were sufficient to characterize this region based on living benthic foraminifera.

Environmental controls on the distribution of living (stained) benthic foraminifera on the continental slope in the Campos Basin area (SW Atlantic)

2018 ◽  
Vol 181 ◽  
pp. 37-52 ◽  
Author(s):  
Cintia Yamashita ◽  
Silvia Helena de Mello e Sousa ◽  
Thaisa Marques Vicente ◽  
Maria Virgínia Martins ◽  
Renata Hanae Nagai ◽  
...  
Keyword(s):  
Continental Slope ◽  
Benthic Foraminifera ◽  
Environmental Controls ◽  
Campos Basin ◽  
Sw Atlantic ◽  
Basin Area

scholarly journals STATISTICAL MULTIVARIATE ANALYSIS APPLIED TO ENVIRONMENTAL CHARACTERIZATION OF SOIL IN SEMIARID REGION1

2019 ◽  
Vol 32 (1) ◽  
pp. 200-210
Author(s):  
Antônio Italcy de Oliveira Júnior ◽  
Luiz Alberto Ribeiro Mendonça ◽  
Sávio de Brito Fontenele ◽  
Adriana Oliveira Araújo ◽  
Maria Gorethe de Sousa Lima Brito
Keyword(s):  
Organic Matter Content ◽  
Principal Component ◽  
Matter Content ◽  
Multivariate Statistical ◽  
Statistical Tool ◽  
Environmental Characterization ◽  
Hierarchical Grouping ◽  
Two Factors ◽  
Total Data

ABSTRACT Soil is a dynamic and complex system that requires a considerable number of samples for analysis and research purposes. Using multivariate statistical methods, favorable conditions can be created by analyzing the samples, i.e., structural reduction and simplification of the data. The objective of this study was to use multivariate statistical analysis, including factorial analysis (FA) and hierarchical groupings, for the environmental characterization of soils in semiarid regions, considering anthropic (land use and occupation) and topographic aspects (altitude, moisture, granulometry, PR, and organic-matter content). As a case study, the São José Hydrographic Microbasin, which is located in the Cariri region of Ceará, was considered. An FA was performed using the principal component method, with normalized varimax rotation. In hierarchical grouping analysis, the “farthest neighbor” method was used as the hierarchical criterion for grouping, with the measure of dissimilarity given by the “square Euclidean distance.” The FA indicated that two factors explain 75.76% of the total data variance. In the analysis of hierarchical groupings, the samples were agglomerated in three groups with similar characteristics: one with samples collected in an area of the preserved forest and two with samples collected in areas with more anthropized soils. This indicates that the statistical tool used showed sensitivity to distinguish the most conserved soils and soils with different levels of anthropization.

Use of AIS data for the environmental characterization of world cruise ship traffic

2019 ◽  
Vol 14 (6) ◽  
pp. 465-474
Author(s):  
Isaías Vicente-Cera ◽  
Asunción Acevedo-Merino ◽  
Juan Antonio López-Ramírez ◽  
Enrique Nebot
Keyword(s):  
Cruise Ship ◽  
Ship Traffic ◽  
Environmental Characterization

Surface Quality of Cavities Obtained by EDM Process

2011 ◽  
Vol 223 ◽  
pp. 931-939
Author(s):  
Rodrigo Panosso Zeilmann ◽  
Gerson Luiz Nicola ◽  
Fernando Moreira Bordin ◽  
Tiago Vacaro ◽  
Mariana Czarnobay Zanotto
Keyword(s):  
Surface Quality ◽  
Electrical Discharge Machining ◽  
Subsurface Layer ◽  
Side Wall ◽  
Machining Processes ◽  
Electrically Conductive ◽  
Machined Parts ◽  
Edm Process

The electrical discharge machining (EDM) is a process widely used in machining of complex geometries and hardened materials, conditions that often are not met by conventional machining processes. In EDM the electrode reproduces its image or geometry on the part and this image is obtained by chip removing process, which is given by high frequency electrical discharges, causing the melting and vaporization of electrically conductive materials. Due to this mechanism of material removal, the surface is subjected to high thermal loads, which heavily influences the surface quality of obtained parts. For the characterization of these surfaces must be considered the surface topography and the metallurgical changes of the subsurface layer, since both characteristics influence the functionality of the machined parts. In addition, several variables related to the EDM process have influence on the characteristics of the generated surface. This work presents a study of the influence of EDM process on the surface quality of square cavities. It was evaluated different regions of the cavities, such as side wall, bottom and corners. The results showed significant differences between the analyzed regions.

Sign in / Sign up

Export Citation Format

Share Document