scholarly journals The Introduction of Prestressed Concrete into the United States : Magnel, the Walnut Lane Bridge, and Beyond

2002 ◽  
Vol 40 (1) ◽  
pp. 82-90
Author(s):  
David P. Billington ◽  
Ryan Woodward
Author(s):  
Basak Aldemir Bektas ◽  
Zachary Hans ◽  
Brent Phares ◽  
Emmanuel Nketah ◽  
Joe Carey ◽  
...  

Bats play an important role in the natural balance of many ecosystems. There has been a growing concern about the bat population in the United States, mainly because of white-nose syndrome (WNS). The primary objective of this work was to better understand what types of bridges are the most likely to be used by bats as roosting locations. In one of the most comprehensive studies in the United States to date, 517 structures in the state of Iowa were inspected for evidence of bat roosting. Logistic regression models were fitted to identify structure, land cover distribution, and predicted bat species distribution characteristics that increase the probability of bat roosting. The final model indicated that probability of bat roosting on bridges increases under the following conditions: structures are prestressed concrete continuous, prestressed concrete or steel continuous; increased superstructure height above ground; increased superstructure depth; increased wetland coverage within a 0.1-mile radius of the structure; and increased number of potential bat species present at the location. The findings show that bridge characteristics, combined with land cover and bat species distribution data, are significant for higher probabilities of bat roosting. This information can be useful to transportation agencies as they plan bridge maintenance and renewal and can also help conservation efforts targeted toward bats. It is thought that the integration of objective, geospatial land cover data with potential bat presence data, and estimation of quantitative and relative influence of variables on probability of bat roosting are unique to this study.


PCI Journal ◽  
1961 ◽  
Vol 6 (1) ◽  
pp. 75-92 ◽  
Author(s):  
Carl F. Renz ◽  
Phillip L. Melville

Author(s):  
A. Hakam ◽  
J.T. Gau ◽  
M.L. Grove ◽  
B.A. Evans ◽  
M. Shuman ◽  
...  

Prostate adenocarcinoma is the most common malignant tumor of men in the United States and is the third leading cause of death in men. Despite attempts at early detection, there will be 244,000 new cases and 44,000 deaths from the disease in the United States in 1995. Therapeutic progress against this disease is hindered by an incomplete understanding of prostate epithelial cell biology, the availability of human tissues for in vitro experimentation, slow dissemination of information between prostate cancer research teams and the increasing pressure to “ stretch” research dollars at the same time staff reductions are occurring.To meet these challenges, we have used the correlative microscopy (CM) and client/server (C/S) computing to increase productivity while decreasing costs. Critical elements of our program are as follows:1) Establishing the Western Pennsylvania Genitourinary (GU) Tissue Bank which includes >100 prostates from patients with prostate adenocarcinoma as well as >20 normal prostates from transplant organ donors.


Author(s):  
Vinod K. Berry ◽  
Xiao Zhang

In recent years it became apparent that we needed to improve productivity and efficiency in the Microscopy Laboratories in GE Plastics. It was realized that digital image acquisition, archiving, processing, analysis, and transmission over a network would be the best way to achieve this goal. Also, the capabilities of quantitative image analysis, image transmission etc. available with this approach would help us to increase our efficiency. Although the advantages of digital image acquisition, processing, archiving, etc. have been described and are being practiced in many SEM, laboratories, they have not been generally applied in microscopy laboratories (TEM, Optical, SEM and others) and impact on increased productivity has not been yet exploited as well.In order to attain our objective we have acquired a SEMICAPS imaging workstation for each of the GE Plastic sites in the United States. We have integrated the workstation with the microscopes and their peripherals as shown in Figure 1.


2001 ◽  
Vol 15 (01) ◽  
pp. 53-87 ◽  
Author(s):  
Andrew Rehfeld

Every ten years, the United States “constructs” itself politically. On a decennial basis, U.S. Congressional districts are quite literally drawn, physically constructing political representation in the House of Representatives on the basis of where one lives. Why does the United States do it this way? What justifies domicile as the sole criteria of constituency construction? These are the questions raised in this article. Contrary to many contemporary understandings of representation at the founding, I argue that there were no principled reasons for using domicile as the method of organizing for political representation. Even in 1787, the Congressional district was expected to be far too large to map onto existing communities of interest. Instead, territory should be understood as forming a habit of mind for the founders, even while it was necessary to achieve other democratic aims of representative government.


Sign in / Sign up

Export Citation Format

Share Document