Analysis and Evaluation of the Development of Various k-Values for Use in Design

2021 ◽  
Author(s):  
Robert Rodden ◽  
Eric Ferrebee
Keyword(s):  
United States ◽  
American Concrete Institute ◽  
The United States ◽  
Concrete Pavement ◽  
Concrete Pavements ◽  
Index Properties ◽  
K Value ◽  
Analysis And Evaluation ◽  
Slabs On Ground

Inconsistency exists between common conversions from soil index properties (e.g., CBR) to a design k-value and a widespread nomograph that has become the definitive industry reference on the topic in the United States. Propagation of these inconsistencies into guidance from groups like the American Concrete Pavement Association (ACPA) and American Concrete Institute (ACI) Committees 330 and 360 has contributed to confusion in the industry. Advancements between the pavement and slab-on-ground communities have occurred in parallel but are inconsistent with each other, thus adding more confusion. ACPA developed a conversion set to better align the industry on a static k-value for design. While the ACPA model is included in StreetPave, PavementDesigner.org, and the ACPA App Library, outdated conversion equations are frequently used due to familiarity and lack of understanding of the underlying principles. This paper presents a summary of the industry's prior practices and recommendations, a detailing of the approach proposed by ACPA, and guidance on which k-value is recommended for design of concrete pavements and slabs-on-ground.

Reflections on 50 years of policy advice in the United States

2018 ◽  
Author(s):  
Laurence E. Lynn
Keyword(s):  
United States ◽  
The United States ◽  
Policy Advice ◽  
American Government ◽  
Rational Analysis ◽  
Political Leaders ◽  
Systematic Analysis ◽  
Non Profit ◽  
Analysis And Evaluation ◽  
Lyndon Johnson

In 1965, U.S. President Lyndon Johnson directed all federal departments and agencies to use a Planning-Programming-Budgeting System (PPBS) to ensure that their annual budget requests were based on the systematic analysis of and justification for their policy and budget recommendations. From America’s earliest days, its political leaders have sought policy advice from experts. In this chapter, Johnson’s mandate will be shown to have been path-breaking in that it initiated the gradual institutionalization of policy planning, analysis, and evaluation at all levels of American government. Policymakers can now draw on the intellectual resources not only of their own organizations but, as well on those of universities, think tanks, consultancies, and non-profit organizations. Rational analysis has not displaced political calculation in policymaking, but it has greatly improved the bases on which public policy is made and implemented in the United States. The challenge to the policy analysis profession now is to vitality, unintellectual diversity and originality, and political relevance that are the basis for the respect it has earned over the years.

Analysis of Current State Rigid Pavement Design Practices in the United States

1996 ◽  
Vol 1525 (1) ◽  
pp. 72-82
Author(s):  
Y. Jiang ◽  
M. I. Darter ◽  
E. Owusu-Antwi
Keyword(s):  
United States ◽  
Concrete Slab ◽  
The United States ◽  
Concrete Pavement ◽  
Pavement Design ◽  
Portland Cement Concrete ◽  
Design Features ◽  
Climatic Regions ◽  
Design Practices ◽  
State Highway

Current portland cement concrete pavement design practices and the key concrete pavement design features used by state highway agencies in the United States are summarized. This information was obtained from a comprehensive survey conducted in 1994 and 1995 under an NCHRP project. Pavement types, design methodologies, and reliability levels are included, along with many design inputs. Parameters that the states use to characterize pavement site conditions, including climate, subgrade, and traffic conditions, are given. The designed concrete slab thicknesses for different site condition combinations are compared. An analysis of variance was conducted to compare the mean slab thicknesses designed in different climatic regions. This examination and summary of the details of current pavement design practices and design features for concrete pavements in the United States will be of interest to both pavement researchers and practitioners.

Correlative microscopy in distrubuted (client/server) computing environments: tools for catalyzing the rapid dissemination of information about the cell biology of the human prostate

1995 ◽  
Vol 53 ◽  
pp. 682-683
Author(s):  
A. Hakam ◽  
J.T. Gau ◽  
M.L. Grove ◽  
B.A. Evans ◽  
M. Shuman ◽  
...  
Keyword(s):  
United States ◽  
Cell Biology ◽  
Tissue Bank ◽  
The United States ◽  
Prostate Adenocarcinoma ◽  
Correlative Microscopy ◽  
Client Server ◽  
Critical Elements ◽  
Transplant Organ

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.

Digital image acquisition, processing, and analysis in a polymer microscopy laboratory

1994 ◽  
Vol 52 ◽  
pp. 454-455
Author(s):  
Vinod K. Berry ◽  
Xiao Zhang
Keyword(s):  
United States ◽  
Image Analysis ◽  
Digital Image ◽  
Image Acquisition ◽  
Image Transmission ◽  
The United States ◽  
Quantitative Image Analysis ◽  
Quantitative Image

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.

Silence of the Land: On the Historical Irrelevance of Territory to Congressional Districting and Political Representation in the United States

2001 ◽  
Vol 15 (01) ◽  
pp. 53-87 ◽  
Author(s):  
Andrew Rehfeld
Keyword(s):  
United States ◽  
House Of Representatives ◽  
Political Representation ◽  
The United States ◽  
Representative Government ◽  
Congressional District ◽  
Congressional Districts ◽  
Communities Of Interest

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.

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