scholarly journals Chemical, mineralogical, and environmental characterization of tunnel boring muds for their valorization in road construction: a focus on molybdenum characterization

2020 ◽  
Vol 27 (35) ◽  
pp. 44314-44324 ◽  
Author(s):  
Adrien Cabrerizo ◽  
David Bulteel ◽  
Julien Waligora ◽  
Gautier Landrot ◽  
Emiliano Fonda ◽  
...  
Keyword(s):  
Road Construction ◽  
Tunnel Boring ◽  
Environmental Characterization

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.

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

Application of nanotechnology in pavement engineering: a review

2020 ◽  
Vol 47 (9) ◽  
pp. 1037-1045
Author(s):  
Peerzada Mosir Shah ◽  
Mohammad Shafi Mir
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Road Construction ◽  
Asphalt Pavements ◽  
Modified Asphalt Binder ◽  
Pavement Engineering ◽  
Scientists And Engineers ◽  
Primary Focus ◽  
Preparation Techniques

Nanotechnology utilizes the research and technology established at the nuclear and molecular or macromolecular levels to comprehend the nanoscale phenomena. In road construction, the bituminous materials are used in enormous amounts. The macroscopic mechanical conduct of these materials still largely relies on microstructure and physical characteristics at a micro and nano scale level. For many years, scientists and engineers have been exploring nanotechnology in civil engineering, but nanotechnology use in this sector has been limited. Nanotechnology has caught the interest of experts and has progressively penetrated into the field of pavement engineering. The article reviews the published works carried out to study the use of nanomaterials in asphalt pavements and illustrates the technique used to enhance asphalt features by the use of these nanomaterials. In this review, multiple nanomaterials are discussed followed by characterization of these nanomaterials, preparation techniques of modified asphalt binder, and finally the effect of nanomaterials on the efficiency of base asphalt binder as well as the asphalt mixture. The primary focus continues on the use of nanotechnology in pavement engineering to achieve a better atmosphere for society based on recognized pavement engineering requirements and difficulties.

scholarly journals Evaluation of Short-Term Aging Protocol for Asphalt Mixtures

2019 ◽  
Vol 9 (14) ◽  
pp. 2783 ◽  
Author(s):  
Sirin ◽  
Paul ◽  
Kassem ◽  
Ohiduzzaman
Keyword(s):  
Mechanical Properties ◽  
Asphalt Pavement ◽  
Road Construction ◽  
Asphalt Mixtures ◽  
Pavement Performance ◽  
Design Stage ◽  
Construction Site ◽  
Short Term ◽  
Compaction Processes

Asphalt mixtures are subjected to short-term aging during the production, placement, and compaction processes. Proper evaluation of asphalt pavement performance relies on the accurate characterization of asphalt mixtures during the design stage. In this study, three different loose asphalt mixtures often used in Qatar were evaluated to develop a laboratory short-term aging procedure. Sample mixtures 1 and 3 were collected from a construction site, while mixture 2 was obtained from an asphalt plant. Virgin aggregates and binders were also collected to reproduce the mixtures in the laboratory. Laboratory-produced mixtures were conditioned at 135 °C using various time durations. The mechanical properties of laboratory-produced mixtures were compared to those of mixtures produced on site. The results of the mechanical and binder testing demonstrated that the proper short-term aging protocol for asphalt mixtures often used in road construction in the State of Qatar would involve heating asphalt mixtures for 4 h at 135 °C before laboratory compaction.

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