86,551 research outputs found
Depositional Controls of the Layered Deposits of Arabia Terra, Mars: Hints From Basin Geometries and Stratigraphic Trends
No full textAn extensive distribution of water-altered equatorial layered deposits (ELDs) characterizes the densely cratered terrain of Arabia Terra (AT), Mars. The majority of these deposits reside within craters and are easily identified by laterally continuous layering. The processes that led to their formation have been widely investigated, but remain unresolved. Furthermore, their precise spatial distribution as a whole, as well as their relationship to one another individually, has yet to be fully appreciated. This work examines 1,013 craters and emphasizes 45 that were observed to contain ELDs within the eastern half of AT. We present the statistical relationships between crater characteristics (e.g., location, diameter, depth), as well as evidence supporting a southeast-northwest facies change. The 30-2,000-m range of measured deposit thicknesses, accompanied with individual layer thicknesses, correlate with crater elevation either due to water level differences within craters, or a proximal-distal relationship to the source. Air fall or fluid expulsion appear to stand out among all the prevailing depositional hypotheses, however the volume required to fill these craters in an ash fall scenario is in opposition with the locations of known volcanic provinces and the volume of ash that volcanic eruptions produce. This new evidence of a regional facies change provides a unique opportunity to better understand past climate and sedimentary processes on Mars, as well as the putative groundwater level in ancient AT. Ultimately, our results do not agree well with a unified depositional method for these deposits and the possibility of mixed origins should be taken seriously
Geological Map of the Equatorial Layered Deposits of the Firsoff crater area: stratigraphic constraints and facies variability
No full text
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
Equatorial Layered Deposits in the Firsoff crater area: process variability and habitability potential
No full textThe depositional processes proposed to explain the formation of the Equatorial Layered Deposits (ELDs) on Mars invoke very different systems such as sub-glacial volcanism, aeolian/airfall, lacustrine, lacustrine/volcanic and spring-fed deposition.
We performed a detailed geological analysis of Firsoff crater and surrounding areas, where ELDs are present within and outside craters, using all the available datasets.
ELDs stay on top of the Noachian Plateau Sequence and are covered by the Hesperian Ridged Plains Material.
Within Firsoff crater, ELDs form a central bulge - estimated more than one kilometer thick - while, outside the craters, ELDs form flat-lying deposits probably not thicker than few tens of meters. Inside craters, terraced-like morphologies made of ELDs are found to mark the topographically highest deposits toward the rim.
Although locally heavily eroded by wind, ELDs within Firsoff crater and within the other craters of the area show several morphologies that appear to be depositional, which would exclude that the craters were originally filled by ELDs.
Within craters, ELDs consist of two facies: a roughly meter thick high albedo layered unit which drape and onlap the Plateau Sequence and hundreds meters large / tens of meters thick cone-shaped mounds made of layered breccia embedded in a matrix. The layered unit is disrupted in a post-depositional polygonal pattern and show no evidence of sedimentary structures. Mounds sometimes display an orifice at the top of their structure. Both facies appear to be linked to and possibly sourced from tectonically controlled fissure ridges. The two facies appear to be stratigraphically in heteropy thus suggesting a temporal as well as a genetic association.
Polyhydrated sulfates have been detected in correspondence of ELDs.
Outside the craters, ELDs show large-scale cross stratification associated to duneforms.
On the base of these morphological, sedimentological and stratigraphic elements, we distinguish between fluid expulsion ELDs forming inside craters and aeolian ELDs outside and the craters.
Fluid expulsion ELDs would result from groundwater upwelling and subsequent evaporitic precipitation, whereas aeolian ELDs from reworking and redeposition of the spring ELDs.
While the climate supporting such a cycle was likely arid by terrestrial standards, these surface conditions in a terrestrial environment would have been conducive for microbial colonization.
The potential for habitable conditions of evaporite settings as shown on analogues on Earth coupled with the high preservation potential within sulfates, make these deposits good candidate to understand the potential past habitability of Mars
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
John F. Kennedy telegram to Roosevelt
No full textJersey Homesteads (later the Borough of Roosevelt) was established in the 1930s as an agro-industrial cooperative community. It was established specifically for urban Jewish garment workers, many of whom had emigrated from Europe. President John F. Kennedy sent a telegram to the citizens of Roosevelt, New Jersey, apologizing for not being able to attend the memorial dedication in honor of former President Franklin Delano Roosevelt. (Jersey Homesteads became Roosevelt in 1945 in honor of the president.) President Kennedy expressed his gratitude to the people of Roosevelt for constructing the memorial, and commented that it will serve as a constant reminder of Roosevelt's good works
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
Maine author Franklin F. Gould recalls his first glimpse of the outside world
No full textMaine author Franklin F. Gould recalls his first glimpse of the outside world as he relates how, as a young farm boy in the late 1800\u27s, he drove his father\u27s horses on an errand to an icebound river
- …
