The Impact of the Implementation of The North American Datum of 1983 (NAD 83) on Aeronautical Navigation in the United States

1993 ◽  
pp. 3-8
Author(s):  
Ronald M. Bolton
Keyword(s):  
United States ◽  
North American ◽  
Traffic Control ◽  
Reference System ◽  
New Technology ◽  
The United States ◽  
Geodetic Reference System ◽  
The North ◽  
Almost All ◽  
The Impact

On October 15, 1992, the horizontal geodetic reference system used for all aeronautical charts and chart-related products published by National Oceanic and Atmospheric Administration (NOAA)/National Ocean Service (NOS) changed from the North American Datum of 1927 (NAO 27) to the North American Datum of 1983 (NAO 83). The Global Positioning System (GPS) now allows satellites to define much more accurately geographic locations in terms of latitude and longitude, utilizing an earth centered reference system; the NAO 83 is based on this new technology. As a result, the latitude and longitude of almost all points in the National Airspace System (NAS) were revised. The greatest coordinate s hifts were in Hawaii and Alaska where latitude moved by as much as 1200 feet and longitude by up to 950 feet. In the conterminous U.S., the largest changes were approximately 165 feet in latitude and 345 feet in longitude. The impact to aeronautical navigation in the C.S. of the datum shift from NAO 27 to NAO 83 was not limited to aeronautical charts and related publications. All Flight Management Systems (FMSs) and Air Traffic Control Systems (ATCs) had to be modified to accept and utilize the NAO 83 coordinates. The impact of the implementation of NAO 83 on aeronautical navigation in the United States was s gnificant.

North American Free Trade Agreement Truck Highway Corridors: U.S.-Mexican Truck Rivers of Trade

1998 ◽  
Vol 1613 (1) ◽  
pp. 71-78 ◽  
Author(s):  
John P. McCray
Keyword(s):  
United States ◽  
Free Trade ◽  
North American ◽  
Free Trade Agreement ◽  
Trade Agreement ◽  
The United States ◽  
Advocacy Groups ◽  
The North ◽  
Federal Highway ◽  
The Impact

The dramatic growth in trade between the United States and Mexico from $12.39 billion to $56.8 billion of U.S. exports and $17.56 billion to $73 billion of U.S. imports between 1977 and 1996 and the implementation of the North American Free Trade Agreement (NAFTA) have focused attention on the impact that the truck-transported portion of this trade has on U.S. highways. State and federal highway administrators are concerned with the planning implications this additional unexpected traffic may have on the transportation infrastructure. Public advocacy groups want additional highway funds to promote one NAFTA highway corridor over others in an effort to stimulate additional economic development. Most of these groups advocate a north-south route through the United States between Canada and Mexico that follows the alignment of an existing federal highway number. Research conducted by the U.S. government under the 1991 Intermodal Surface Transportation Efficiency Act has failed to define NAFTA highway corridors adequately, leaving policy makers with little concrete information with which to combat the rhetoric of the trade highway corridor advocacy groups. A report is provided on research critical to the needs of both highway administrators and corridor advocacy groups, namely, the location of U.S.-Mexican trade highway corridors and the trade truck density along these corridors.

Mexican fresh tomato exports in the North American market: A case study of the effects of productivity on competitiveness

2013 ◽  
Vol 93 (5) ◽  
pp. 839-850 ◽  
Author(s):  
Mercedes Borja-Bravo ◽  
José Alberto García-Salazar ◽  
Rhonda K. Skaggs
Keyword(s):  
United States ◽  
North American ◽  
The United States ◽  
Tomato Production ◽  
The North ◽  
North American Market ◽  
The Us ◽  
Fresh Tomato ◽  
The Impact

Borja-Bravo, M., García-Salazar, J. A. and Skaggs, R. K. 2013. Mexican fresh tomato exports in the North American market: A case study of the effects of productivity on competitiveness. Can. J. Plant Sci. 93: 839–850. The North American market for fresh tomatoes (Lycopersicon escolentum Mill.) involves a complicated web of bilateral trading relationships between the United States, Mexico and Canada. Trade in fresh tomatoes between the three countries has changed significantly in recent years. In particular, Mexico's share of total US fresh tomato imports from all countries decreased from 93 to 88%, while Canada's share of US fresh tomato imports increased from 3 to 11% between 1996 and 2009. Mexico's declining competitive position in the US fresh tomato market is also evidenced by the fact that the Mexican share of combined Mexico–Canada exports to the United States decreased from 97% to 89% between 1996 and 2009. A spatial and inter-temporal model was used to analyze the impact of increased Mexican tomato yields on the North American fresh tomato market. Results indicate that for the average year between 2005 and 2008, 20% higher yields would have resulted in a 15.1% increase in Mexico's tomato production and a 28.9% increase in fresh tomato exports from Mexico to the United States. As a result of higher Mexican tomato sector productivity, Canadian and US producers’ shares of the US fresh tomato market would decrease and Mexico's would increase from 35.0 to 41.9%. The model shows that Mexico's share of US fresh tomato imports from both Mexico and Canada would grow from 88.1 to 90.3% as a result of the increased productivity. These results lead to the recommendation that increasing yields of this important export crop are key to maintaining and increasing the North American market competitiveness of Mexican-produced fresh tomatoes.

scholarly journals “The Future of Archaeology Is Antiracist”: Archaeology in the Time of Black Lives Matter

2021 ◽  
pp. 1-20
Author(s):  
Ayana Omilade Flewellen ◽  
Justin P. Dunnavant ◽  
Alicia Odewale ◽  
Alexandra Jones ◽  
Tsione Wolde-Michael ◽  
...  
Keyword(s):  
United States ◽  
North American ◽  
The United States ◽  
Heritage Preservation ◽  
Social Unrest ◽  
Black Lives Matter ◽  
The North ◽  
Road Map ◽  
The Social ◽  
The Future

This forum builds on the discussion stimulated during an online salon in which the authors participated on June 25, 2020, entitled “Archaeology in the Time of Black Lives Matter,” and which was cosponsored by the Society of Black Archaeologists (SBA), the North American Theoretical Archaeology Group (TAG), and the Columbia Center for Archaeology. The online salon reflected on the social unrest that gripped the United States in the spring of 2020, gauged the history and conditions leading up to it, and considered its rippling throughout the disciplines of archaeology and heritage preservation. Within the forum, the authors go beyond reporting the generative conversation that took place in June by presenting a road map for an antiracist archaeology in which antiblackness is dismantled.

A SYNOPSIS OF THE NORTH AMERICAN SPECIES OF SYNDIPNUS (HYMEN., ICHNEUMONIDAE)

1940 ◽  
Vol 72 (7) ◽  
pp. 135-145 ◽  
Author(s):  
G. Stuart Walley
Keyword(s):  
United States ◽  
North American ◽  
The United States ◽  
North American Species ◽  
National Museum ◽  
United States National Museum ◽  
The North

As noted below the two North American species described in Syndipnus by workers appear to belong in other genrra. In Europe the gunus is represented by nearly a score of species and has been reviewed in recent years by two writers (1, 2). North American collections contain very few representatives of the genus; after combining the material in the National Collection with that from the United States National Museum, the latter kindly loaned to me by Mr. R. A. Cushman, only thirty-seven specimens are available for study.

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