An analytical approach for dynamic response of timber railroad bridges

1990 ◽  
Vol 17 (6) ◽  
pp. 952-964
Author(s):  
A. S. Uppal ◽  
R. B. Pinkney ◽  
S. H. Rizkalla
Keyword(s):  
Dynamic Response ◽  
Analytical Approach ◽  
The United States ◽  
Constant Speed ◽  
Attractive Alternative ◽  
Railroad Bridges ◽  
Vertical Displacements ◽  
Current Design ◽  
The Subject ◽  
Bridge Spans

In the 1970s, it was reported that there were approximately 3700 track kilometers of timber railroad bridges in the United States and Canada. For short spans, they offer an attractive alternative to other types of bridges, as they are economical, faster to construct, and easy to maintain. Current design practices do not allow an independent consideration of the effects of the dynamic loads in sizing the bridge components, because very little information is available on the subject. Dynamic tests were carried out in 1986 on timber bridge spans at two test sites using test trains consisting of a locomotive unit, two loaded hopper cars, and a caboose. This paper gives a brief description of the analytical approach employed for determining the dynamic response of timber bridge spans under railway vehicles travelling at a constant speed. The model comprises a multi-degree-of-freedom system with each vehicle having bounce, pitch, and roll movements. Two parallel chords, each having its distributed mass lumped at discrete points, were used to idealize the bridge spans. A computer program developed on this basis was used to predict the loads at the wheel–rail interfaces and the vertical displacements at the discrete points on the spans. The predicted loads at wheel–rail interfaces and the maximum vertical displacements were found to be in agreement within about 20% and 16% respectively of the measured values. The program was utilized to study the effect of speed and other factors on the dynamic response of open-deck and ballast-deck bridges. Key words: analytical approach, timber railway bridge, railway locomotive and cars, constant speed, wheel–rail interface, loads, displacements, accelerations, dynamic response.

Response of timber bridges under train loading

1990 ◽  
Vol 17 (6) ◽  
pp. 940-951 ◽  
Author(s):  
A. S. Uppal ◽  
S. H. Rizkalla ◽  
R. B. Pinkney
Keyword(s):  
Load Factor ◽  
Attractive Alternative ◽  
Dynamic Displacement ◽  
Load Factors ◽  
Vertical Displacements ◽  
Current Design ◽  
Train Speed ◽  
Bridge Spans ◽  
Timber Bridges ◽  
Normal Track

Timber bridges are still commonly used by several North American railroads. For short spans, they offer an attractive alternative to other types of bridges, as they are economical, faster to construct, and easy to maintain. Current design practices do not allow an independent consideration of the effects of the dynamic loads in sizing the bridge components, because very little information is available on the subject. Dynamic tests were carried out at two timber railroad bridge sites under the passage of trains at speeds varying from crawl, i.e., 1.6 km/h (1 mph), to 80.5 km/h (50 mph). The loads at wheel–rail interfaces, the vertical displacements, and the accelerations were measured at several locations on the bridge spans, the bridge approaches, and the normal track sections. The maximum values of the dynamic load factors obtained were 1.50, 1.65, and 1.85 for bridge, bridge approach, and normal track, respectively; and the corresponding maximum values of the dynamic displacement factors obtained were 1.30, 1.00, and 1.20. The main objective of this paper is to describe the experimental work and the influence on the measured values of the train speed and other factors. Key words: railroad, timber, bridge, wheel–rail interfaces, load, deflection, frequency, load factor, dynamic displacement, track modulus.

The Dynamics of TAT Process

2014 ◽  
Vol 35 (2) ◽  
pp. 103-133 ◽  
Author(s):  
Benoît Verdon ◽  
Catherine Chabert ◽  
Catherine Azoulay ◽  
Michèle Emmanuelli ◽  
Françoise Neau ◽  
...  
Keyword(s):  
Defense Mechanisms ◽  
Analytical Approach ◽  
Therapeutic Process ◽  
Practice Research ◽  
Rorschach Test ◽  
Mental Functioning ◽  
Projective Tests ◽  
The Subject ◽  
Latent Content ◽  
Rigorous Method

After many years of clinical practice, research and the teaching of projective tests, Shentoub and her colleagues (Debray, Brelet, Chabert & al.) put forward an original and rigorous method of analysis and interpretation of the TAT protocols in terms of psychoanalysis and clinical psychopathology. They developed the TAT process theory in order to understand how the subject builds a narrative. Our article will emphasize the source of the analytical approach developed by V. Shentoub in the 1950s to current research; the necessity of marking the boundary between the manifest and latent content in the cards; the procedure for analyzing the narrative, supported by an analysis sheet for understanding the stories' structure and identifying the defense mechanisms; and how developing hypotheses about how the mental functions are organized, as well as their potential psychopathological characteristics; and the formulation of a diagnosis in psychodynamic terms. In conjunction with the analysis and interpretation of the Rorschach test, this approach allows us to develop an overview of the subject's mental functioning, taking into account both the psychopathological elements that may threaten the subject and the potential for a therapeutic process. We will illustrate this by comparing neurotic, borderline, and psychotic personalities.

Liberal Internationalism from George W. Bush to Barack Obama

2017 ◽  
Author(s):  
Tony Smith
Keyword(s):  
United States ◽  
The United States ◽  
Barack Obama ◽  
Democratic Peace ◽  
War On Terrorism ◽  
Global War On Terrorism ◽  
Liberal Internationalism ◽  
Liberal Democratic ◽  
The Subject ◽  
Global War

This chapter examines the United States' liberal democratic internationalism from George W. Bush to Barack Obama. It first considers the Bush administration's self-ordained mission to win the “global war on terrorism” by reconstructing the Middle East and Afghanistan before discussing the two time-honored notions of Wilsonianism espoused by Democrats to make sure that the United States remained the leader in world affairs: multilateralism and nation-building. It then explores the liberal agenda under Obama, whose first months in office seemed to herald a break with neoliberalism, and his apparent disinterest in the rhetoric of democratic peace theory, along with his discourse on the subject of an American “responsibility to protect” through the promotion of democracy abroad. The chapter also analyzes the Obama administration's economic globalization and concludes by comparing the liberal internationalism of Bush and Obama.

The dimensions of the Moroccan position on the Gulf crisis 1990-1991

2019 ◽  
Vol 3 (11) ◽  
pp. 179
Author(s):  
Nazhan Hammoud Nassif Al Obeidi ◽  
Abdul Wahab Abdul Aziz Abu Khamra
Keyword(s):  
United States ◽  
United States Of America ◽  
New World ◽  
World Order ◽  
The United States ◽  
New World Order ◽  
Historical Events ◽  
Gulf Crisis ◽  
The Subject

The Gulf crisis 1990-1991 is one of the important historical events of the 1990s, which gave rise to the new world order by the sovereignty of the United States of America on this system. The Gulf crisis was an embodiment to clarify the features of this system. .     The crisis in the Gulf was an opportunity for the Moroccans to manage this complex event and to use it for the benefit of the Moroccan situation. Therefore, the bilateral position of the crisis came out as a rejection, a contradiction and a supporter of political and economic dimensions at the external and internal levels. On the Moroccan situation, and from these points came the choice of the subject of the study (the dimensions of the Moroccan position from the Gulf crisis 1990-1991), which shows the ingenuity of Moroccans in managing an external crisis and benefiting from it internally.

Anne O. Krueger, Constantine Michalopoulos and Vernon W. Ruttan. Aid and Development. Baltimore: The Johns Hopkins University Press. 1989. xiv + 386 pp.Price: U.S. $ 52.00

1991 ◽  
Vol 30 (2) ◽  
pp. 213-217
Author(s):  
Mir Annice Mahmood
Keyword(s):  
United States ◽  
Economic Development ◽  
International Development ◽  
Western Europe ◽  
Development Assistance ◽  
The United States ◽  
Social Infrastructure ◽  
Low Literacy ◽  
The Subject ◽  
The Impact

Foreign aid has been the subject of much examination and research ever since it entered the economic armamentarium approximately 45 years ago. This was the time when the Second World War had successfully ended for the Allies in the defeat of Germany and Japan. However, a new enemy, the Soviet Union, had materialized at the end of the conflict. To counter the threat from the East, the United States undertook the implementation of the Marshal Plan, which was extremely successful in rebuilding and revitalizing a shattered Western Europe. Aid had made its impact. The book under review is by three well-known economists and is the outcome of a study sponsored by the Department of State and the United States Agency for International Development. The major objective of this study was to evaluate the impact of assistance, i.e., aid, on economic development. This evaluation however, was to be based on the existing literature on the subject. The book has five major parts: Part One deals with development thought and development assistance; Part Two looks at the relationship between donors and recipients; Part Three evaluates the use of aid by sector; Part Four presents country case-studies; and Part Five synthesizes the lessons from development assistance. Part One of the book is very informative in that it summarises very concisely the theoretical underpinnings of the aid process. In the beginning, aid was thought to be the answer to underdevelopment which could be achieved by a transfer of capital from the rich to the poor. This approach, however, did not succeed as it was simplistic. Capital transfers were not sufficient in themselves to bring about development, as research in this area came to reveal. The development process is a complicated one, with inputs from all sectors of the economy. Thus, it came to be recognized that factors such as low literacy rates, poor health facilities, and lack of social infrastructure are also responsible for economic backwardness. Part One of the book, therefore, sums up appropriately the various trends in development thought. This is important because the book deals primarily with the issue of the effectiveness of aid as a catalyst to further economic development.

Studies of Islam, Economics, and Governance

1994 ◽  
Vol 11 (1) ◽  
pp. 38-70
Author(s):  
Florence Eid
Keyword(s):  
United States ◽  
Ford Foundation ◽  
The United States ◽  
The State ◽  
Edward Said ◽  
The Subject ◽  
State Of Research ◽  
Traditional Approaches ◽  
Islamic Values

IntroductionThis paper is a report on the state of research in two areas of Islamicstudies: Islam and economics and Islam and governance. I researched andwrote it as part of my internship at the Ford Foundation during the summerof 1992. On Discourse. The study of Islam in the United States has moved far beyondthe traditional historical and philological methods. This is perhapsbest explained by the development of analytically rigorous social sciencemethods that have contributed to a better balance between the humanisticconcerns of the more traditional approaches and efforts at systematizingthe study of Islam and classifying it across boundaries of communities,religions, even epochs. This is said to have s t a d with the developmentof irenic attitudes towards Islam, which changed the direction of westemorientalist writings from indifference (at best) and often open hostility toand contempt of Islamic values (however they were understood) to phenomenologicalworks by scholars who saw the study of Islam as somethingto be taken seriously and for its own sake, which is best exemplifiedby Clifford Geertz's Islam Observed.The work of Edward Said contested this evolution, and the publicationof his Orientalism has been described as "a stick of dynamite"' that,despite its impact in mobilizing a reevaluation of the field, was unwarrantedin its pessimism. In any case, the field has continued to evolve,with the most powerful force moving it being the subject itself. Thephenomenological/orientalist approach, if we can point to one today, ...

The Oxford Handbook of Comic Book Studies

2019 ◽  
Keyword(s):  
United States ◽  
Comic Books ◽  
Academic Discipline ◽  
World System ◽  
Comic Book ◽  
The United States ◽  
Global Perspective ◽  
Visual Narrative ◽  
The Subject ◽  
Book Studies

Comic book studies has developed as a solid academic discipline, becoming an increasingly vibrant and field in the United States and globally. A growing number of dissertations, monographs, and edited books publish every year on the subject, while world comics represent the fastest-growing sector of publishing. The Oxford Handbook of Comic Book Studies examines the history and evolution of the visual narrative genre from a global perspective, bringing together readable, jargon-free essays written by established and emerging scholars from diverse geographic, institutional, gender, and national backgrounds. In particular, the Handbook explores how the term “global comics” has been defined, as well the major movements and trends that drive the field. Each essay will help readers understand comic books as a storytelling form grown within specific communities, and will also show how these forms exist within what can be considered a world system of comics.

scholarly journals Indigenous Water Rights in Comparative Law

2020 ◽  
Vol 9 (3) ◽  
pp. 393-402
Author(s):  
Elizabeth Macpherson
Keyword(s):  
Human Population ◽  
Global Financial Crisis ◽  
Water Rights ◽  
The United States ◽  
Wall Street ◽  
Award Winning ◽  
The Subject ◽  
Academy Award ◽  
Increasing Demand ◽  
Poor Management

At the end of the 2015 Academy Award-winning film The Big Short, which explores the origins of the 2008 Global Financial Crisis, a caption notes that the Wall Street investor protagonist of the film who predicted the collapse of the United States (US) housing market would now be ‘focused on one commodity: water’. Water is sometimes described in popular culture as ‘the new oil’ or ‘more valuable than gold’. It is predicted to be the subject of increasing uncertainty, competition, conflict, and even war, as increasing demand from a growing human population and development meets reduced supply as a result of poor management, overuse, and climate change.

Sign in / Sign up

Export Citation Format

Share Document