The fourth coast, revisited

2021 ◽  
pp. 205301962110446
Author(s):  
John Kim
Keyword(s):  
Mississippi River ◽  
Entire Length ◽  
Anthropogenic Structures

The author traveled for 2.5 months by canoe and other modes of transport down the entire length of the Mississippi River with the Mississippi. An Anthropocene River project. Reflecting on this journey, this essay revisits Catherine Brown and William Morrish’s 1991 essay, The Fourth Coast: An Expedition on the Mississippi River, in which Brown and Morrish document their research efforts to identify coherent anthropogenic structures and systems that could warrant the characterization of the Mississippi River as a Fourth Coast. To encourage a flourishing of overlapping multispecies life, the essay moves beyond their spatial reimagining by defining the “distributed nature of home” as a model for conceptualizing distributed spatialities and plural temporalities along the Mississippi River.

scholarly journals Automated characterization of ridge-swale patterns along the Mississippi River

2021 ◽  
Author(s):  
Alicia Downard ◽  
Stephen Semmens ◽  
Bryant Robbins
Keyword(s):  
Mississippi River ◽  
Machine Learning Algorithms ◽  
Training Data ◽  
Mississippi Valley ◽  
Lower Mississippi Valley ◽  
Linear Feature ◽  
Topographic Features ◽  
Backward Erosion Piping ◽  
The Individual

The orientation of constructed levee embankments relative to alluvial swales is a useful measure for identifying regions susceptible to backward erosion piping (BEP). This research was conducted to create an automated, efficient process to classify patterns and orientations of swales within the Lower Mississippi Valley (LMV) to support levee risk assessments. Two machine learning algorithms are used to train the classification models: a convolutional neural network and a U-net. The resulting workflow can identify linear topographic features but is unable to reliably differentiate swales from other features, such as the levee structure and riverbanks. Further tuning of training data or manual identification of regions of interest could yield significantly better results. The workflow also provides an orientation to each linear feature to support subsequent analyses of position relative to levee alignments. While the individual models fall short of immediate applicability, the procedure provides a feasible, automated scheme to assist in swale classification and characterization within mature alluvial valley systems similar to LMV.

Characterization of nutrient, organic carbon, and sediment loads and concentrations from the Mississippi River into the northern Gulf of Mexico

2007 ◽  
Vol 30 (5) ◽  
pp. 773-790 ◽  
Author(s):  
R. E. Turner ◽  
N. N. Rabalais ◽  
R. B. Alexander ◽  
G. McIsaac ◽  
R. W. Howarth
Keyword(s):  
Organic Carbon ◽  
Gulf Of Mexico ◽  
Mississippi River ◽  
Northern Gulf Of Mexico ◽  
Sediment Loads

scholarly journals Morphological characterization of natural orchids Dendrobium spp.

2021 ◽  
Vol 905 (1) ◽  
pp. 012139
Author(s):  
S Hartati ◽  
Samanhudi ◽  
O Cahyono ◽  
A N Hariyadi
Keyword(s):  
Morphological Character ◽  
Morphological Characterization ◽  
Similarity Coefficient ◽  
Entire Length ◽  
The Other ◽  
Molecular Characteristic ◽  
Similarity Matrix ◽  
Quantitative Properties ◽  
The Relationship

Abstract Dendrobium is characterized by long pseudobulbs or canes with soft leaves over the entire length, or in some species short or swollen pseudobulbs with two leathery leaves. The inflorescence is composed from dozens of flowers of different sizes and colors. This study aimed to identify the quantitative morphological character of five species of Dendrobium spp. namely D. mirbelianum, D. lamellatum from Java, D. anosmum from South Kalimantan, D. bracteosum from Papua, and D. purpureum from North Sumatera. The resulted dendrogram based on the similarity matrix were divided into two clusters, among the five species the value of similarity coefficient is 1.50. The first cluster is only composed from D. mirbelianum, the second cluster is D. lamellatum, D. purpureum, D. bracteosum, and D. anosmum which have more distant relationship with the other three orchids. Moreover, D. lamellatum and D. purpureum have the closest similarity coefficient with 0.81 value, which have bigger chance to use as the parents for hybridization. There are many Dendrobiums spp. distribution which based on the relationship area. In addition to quantitative properties, it also needs to be expanded to qualitative, anatomy, cytology, and also molecular characteristic to have more comprehensive data.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

Characterization of Coherent, Ordered Precipitates in Nickel-Base Alloys

1973 ◽  
Vol 31 ◽  
pp. 144-145
Author(s):  
B. H. Kear ◽  
J. M. Oblak
Keyword(s):  
Stable Phase ◽  
Nickel Base Superalloy ◽  
Alloy 718 ◽  
Commercial Alloy ◽  
Precipitate Morphology ◽  
Continuous Precipitation ◽  
Nickel Base ◽  
Base Superalloy ◽  
Strengthening Precipitate

A nickel-base superalloy is essentially a Ni/Cr solid solution hardened by additions of Al (Ti, Nb, etc.) to precipitate a coherent, ordered phase. In most commercial alloy systems, e.g. B-1900, IN-100 and Mar-M200, the stable precipitate is Ni3 (Al,Ti) γ′, with an LI2structure. In A lloy 901 the normal precipitate is metastable Nis Ti3 γ′ ; the stable phase is a hexagonal Do2 4 structure. In Alloy 718 the strengthening precipitate is metastable γ″, which has a body-centered tetragonal D022 structure.Precipitate MorphologyIn most systems the ordered γ′ phase forms by a continuous precipitation re-action, which gives rise to a uniform intragranular dispersion of precipitate particles. For zero γ/γ′ misfit, the γ′ precipitates assume a spheroidal.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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