Density Currents in connection with the problem of Submarine Canyons

1938 ◽  
Vol 75 (6) ◽  
pp. 241-249 ◽  
Author(s):  
Ph. H. Kuenen

The investigation of submarine canyons has been actively pursued in the United States of latter years, principally due to the activities of F. P. Shepard. The Coast and Geodetic Survey has mapped a large number of these interesting chasms, both along the Atlantic and Pacific continental slopes, by sonic soundings; Shepard himself added data by soundings and dredgings along the Californian coast; Stetson performed current measurements, dredgings, and sampling in the canyons off the east coast. The number of data is steadily increasing in the United States, and it is to be hoped other nations will also become active, for much still remains to be learned before a comprehensive view of the many-sided problem can be obtained.


1997 ◽  
Vol 7 (2) ◽  
pp. 195-223
Author(s):  
Lillian Taiz

Forty-eight hours after they landed in New York City in 1880, a small contingent of the Salvation Army held their first public meeting at the infamous Harry Hill's Variety Theater. The enterprising Hill, alerted to the group's arrival from Britain by newspaper reports, contacted their leader, Commissioner George Scott Railton, and offered to pay the group to “do a turn” for “an hour or two on … Sunday evening.” In nineteenth-century New York City, Harry Hill's was one of the best known concert saloons, and reformers considered him “among the disreputable classes” of that city. His saloon, they said, was “nothing more than one of the many gates to hell.”







Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4336
Author(s):  
Piervincenzo Rizzo ◽  
Alireza Enshaeian

Bridge health monitoring is increasingly relevant for the maintenance of existing structures or new structures with innovative concepts that require validation of design predictions. In the United States there are more than 600,000 highway bridges. Nearly half of them (46.4%) are rated as fair while about 1 out of 13 (7.6%) is rated in poor condition. As such, the United States is one of those countries in which bridge health monitoring systems are installed in order to complement conventional periodic nondestructive inspections. This paper reviews the challenges associated with bridge health monitoring related to the detection of specific bridge characteristics that may be indicators of anomalous behavior. The methods used to detect loss of stiffness, time-dependent and temperature-dependent deformations, fatigue, corrosion, and scour are discussed. Owing to the extent of the existing scientific literature, this review focuses on systems installed in U.S. bridges over the last 20 years. These are all major factors that contribute to long-term degradation of bridges. Issues related to wireless sensor drifts are discussed as well. The scope of the paper is to help newcomers, practitioners, and researchers at navigating the many methodologies that have been proposed and developed in order to identify damage using data collected from sensors installed in real structures.



2021 ◽  
Vol 172 ◽  
pp. 1212-1224
Author(s):  
Seongho Ahn ◽  
Vincent S. Neary ◽  
Mohammad Nabi Allahdadi ◽  
Ruoying He


Modern Italy ◽  
2021 ◽  
pp. 1-17
Author(s):  
Gilberto Mazzoli

During the Age of Mass Migration more than four million Italians reached the United States. The experience of Italians in US cities has been widely explored: however, the study of how migrants adjusted in relation to nature and food production is a relatively recent concern. Due to a mixture of racism and fear of political radicalism, Italians were deemed to be undesirable immigrants in East Coast cities and American authorities had long perceived Italian immigrants as unclean, unhealthy and carriers of diseases. As a flipside to this narrative, Italians were also believed to possess a ‘natural’ talent for agriculture, which encouraged Italian diplomats and politicians to propose the establishment of agricultural colonies in the southern United States. In rural areas Italians could profit from their agricultural skills and finally turn into ‘desirable immigrants’. The aim of this paper is to explore this ‘emigrant colonialism’ through the lens of environmental history, comparing the Italian and US diplomatic and public discourses on the potential and limits of Italians’ agricultural skills.



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