scholarly journals Hydraulic Modeling and Evaluation Equations for the Incipient Motion of Sandbags for Levee Breach Closure Operations

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 279 ◽  
Author(s):  
Ahmed M.A. Sattar ◽  
Hossein Bonakdari ◽  
Bahram Gharabaghi ◽  
Artur Radecki-Pawlik
Keyword(s):  
Open Channel ◽  
Hydrodynamic Characteristic ◽  
The United States ◽  
Hydraulic Modeling ◽  
Experimental Results ◽  
Army Corps ◽  
Incipient Motion ◽  
Critical Flow Velocity ◽  
Levee Breach

Open channel levees are used extensively in hydraulic and environmental engineering applications to protect the surrounding area from inundation. However, levees may fail to produce an unsteady flow that is inherently three dimensional. Such a failure may lead to a destructive change in morphology of the river channel and valley. To avoid such a situation arising, hydraulic laboratory modeling was performed on an open channel levee breach model capturing velocity, in x, y and z plans, at selected locations in the breach. Sandbags of various shapes and sizes are tested for incipient motion by the breach flow. We found that a prism sandbag has a better hydrodynamic characteristic and more stability than spherical bags with the same weight. Experimental results are then used to evaluate existing empirical equations and to develop more accurate equations for predicting critical flow velocity at the initial stage of sandbag motion. Results showed the superior predictions a few of the equations could be considered with an uncertainty range of ±10%. These equations explained the initial failed attempts of the United States Army Corps of Engineers (USACE) for breach closure of the case study, and confirmed the experimental results are simulating the case study of breach closure.

scholarly journals Vulnerability curves for masonry buildings affected by hyperconcentrated flows as natural disaster risk management tools for the quantification of material damage

2021 ◽  
Vol 958 (1) ◽  
pp. 012021
Author(s):  
A Jara ◽  
T Y Quispe ◽  
L F Castillo
Keyword(s):  
El Niño ◽  
Hydrological Modeling ◽  
El Nino ◽  
Climatic Variability ◽  
The United States ◽  
Hydraulic Modeling ◽  
Army Corps ◽  
Masonry Buildings ◽  
Management Tools ◽  
Confined Masonry

Abstract The damage assessment caused by floods, earthquakes, hurricanes among others phenomenons in the world are analyzed with methodologies such as “Vulnerability curves”. In Peru, disasters caused by hyperconcentrated flows are alarming due to a climatic variability such as the “El Niño Costero” phenomenon. Therefore, this research has developed vulnerability curves for 1 and 2-story confined masonry buildings in Urb. San Idelfonso, Ica - Peru; linking the variables: flow depth, associated with the event produced by heavy rains at the top of the “Quebrada Cansas” caused by the “El Niño Costero” phenomenon in 2017, and the percentage of the damage based on the methodology of the United States Army Corps of Engineers (USACE), whose formula is the repair value and total building value. The monetary amounts and items of the buildings are obtained from the RM 415-2017-VIVIENDA of the Ministry of Housing, Construction and Sanitation of Peru. The process consisted of hydrological modeling in HEC-HMS, hydraulic modeling in FLO-2D, damage percentage estimate and vulnerability curves production. Finally, the vulnerability curves for hyperconcentrated flows were contrasted with similar studies regarding curves for flooding and debris flow. The results of the investigation showed that the “El Niño Costero” phenomenon in 2017 had an economic impact of at least 1.3 million soles in Urb. San Idelfonso. In addition, at least 24 buildings had a complete damage and 21 buildings an extensive damage.

Gendered differences in emigration and mobility perspectives among European researchers working abroad

2014 ◽  
Vol 7 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Elisabeth Scheibelhofer
Keyword(s):  
United States ◽  
Qualitative Research ◽  
Qualitative Study ◽  
Social Relations ◽  
The United States ◽  
Research Strategy ◽  
The Future ◽  
Highly Skilled

This paper focuses on gendered mobilities of highly skilled researchers working abroad. It is based on an empirical qualitative study that explored the mobility aspirations of Austrian scientists who were working in the United States at the time they were interviewed. Supported by a case study, the paper demonstrates how a qualitative research strategy including graphic drawings sketched by the interviewed persons can help us gain a better understanding of the gendered importance of social relations for the future mobility aspirations of scientists working abroad.

‘A Routh O’ Auld Nick-Nackets’ – the antiquarian collection of John Rae

2015 ◽  
Vol 36-37 (1) ◽  
pp. 163-183
Author(s):  
Paul Taylor
Keyword(s):  
United States ◽  
Nineteenth Century ◽  
Social Context ◽  
Moral Education ◽  
The United States ◽  
Representative Case ◽  
National Museums ◽  
The Individual ◽  
The University

John Rae, a Scottish antiquarian collector and spirit merchant, played a highly prominent role in the local natural history societies and exhibitions of nineteenth-century Aberdeen. While he modestly described his collection of archaeological lithics and other artefacts, principally drawn from Aberdeenshire but including some items from as far afield as the United States, as a mere ‘routh o’ auld nick-nackets' (abundance of old knick-knacks), a contemporary singled it out as ‘the best known in private hands' (Daily Free Press 4/5/91). After Rae's death, Glasgow Museums, National Museums Scotland, the University of Aberdeen Museum and the Pitt Rivers Museum in Oxford, as well as numerous individual private collectors, purchased items from the collection. Making use of historical and archive materials to explore the individual biography of Rae and his collection, this article examines how Rae's collecting and other antiquarian activities represent and mirror wider developments in both the ‘amateur’ antiquarianism carried out by Rae and his fellow collectors for reasons of self-improvement and moral education, and the ‘professional’ antiquarianism of the museums which purchased his artefacts. Considered in its wider nineteenth-century context, this is a representative case study of the early development of archaeology in the wider intellectual, scientific and social context of the era.

Varied Responses to Human-Induced Seismicity in the City of Azle, Texas

2019 ◽  
Vol 3 (1) ◽  
pp. 1-8
Author(s):  
Sarmistha R. Majumdar
Keyword(s):  
State Government ◽  
Induced Seismicity ◽  
Oil And Gas ◽  
The United States ◽  
The State ◽  
Prior History ◽  
Small Community ◽  
Regulatory Policies ◽  
The Status

Fracking has helped to usher in an era of energy abundance in the United States. This advanced drilling procedure has helped the nation to attain the status of the largest producer of crude oil and natural gas in the world, but some of its negative externalities, such as human-induced seismicity, can no longer be ignored. The occurrence of earthquakes in communities located at proximity to disposal wells with no prior history of seismicity has shocked residents and have caused damages to properties. It has evoked individuals’ resentment against the practice of injection of fracking’s wastewater under pressure into underground disposal wells. Though the oil and gas companies have denied the existence of a link between such a practice and earthquakes and the local and state governments have delayed their responses to the unforeseen seismic events, the issue has gained in prominence among researchers, affected community residents, and the media. This case study has offered a glimpse into the varied responses of stakeholders to human-induced seismicity in a small city in the state of Texas. It is evident from this case study that although individuals’ complaints and protests from a small community may not be successful in bringing about statewide changes in regulatory policies on disposal of fracking’s wastewater, they can add to the public pressure on the state government to do something to address the problem in a state that supports fracking.

Shale Resources, Parks Conservation, and Contested Public Lands in North Dakota’s Theodore Roosevelt National Park: Is Fracking Booming?

2020 ◽  
Vol 4 (1) ◽  
pp. 1-13
Author(s):  
Miriam R. Aczel ◽  
Karen E. Makuch
Keyword(s):  
National Park ◽  
Oil And Gas ◽  
The United States ◽  
Federal Agencies ◽  
Cultural Significance ◽  
Theodore Roosevelt ◽  
Natural Beauty ◽  
Theodore Roosevelt National Park ◽  
Bakken Shale

This case study analyzes the potential impacts of weakening the National Park Service’s (NPS) “9B Regulations” enacted in 1978, which established a federal regulatory framework governing hydrocarbon rights and extraction to protect natural resources within the parks. We focus on potential risks to national parklands resulting from Executive Orders 13771—Reducing Regulation and Controlling Regulatory Costs [1]—and 13783—Promoting Energy Independence and Economic Growth [2]—and subsequent recent revisions and further deregulation. To establish context, we briefly overview the history of the United States NPS and other relevant federal agencies’ roles and responsibilities in protecting federal lands that have been set aside due to their value as areas of natural beauty or historical or cultural significance [3]. We present a case study of Theodore Roosevelt National Park (TRNP) situated within the Bakken Shale Formation—a lucrative region of oil and gas deposits—to examine potential impacts if areas of TRNP, particularly areas designated as “wilderness,” are opened to resource extraction, or if the development in other areas of the Bakken near or adjacent to the park’s boundaries expands [4]. We have chosen TRNP because of its biodiversity and rich environmental resources and location in the hydrocarbon-rich Bakken Shale. We discuss where federal agencies’ responsibility for the protection of these lands for future generations and their responsibility for oversight of mineral and petroleum resources development by private contractors have the potential for conflict.

Turning Aliens into Socialists

2010 ◽  
Vol 1 (1) ◽  
pp. 75-93
Author(s):  
Jessica Moberg
Keyword(s):  
Outer Space ◽  
The United States ◽  
Second World War ◽  
World War ◽  
History Of ◽  
Swedish History ◽  
Second World ◽  
The Universe ◽  
Highly Evolved

Immediately after the Second World War Sweden was struck by a wave of sightings of strange flying objects. In some cases these mass sightings resulted in panic, particularly after authorities failed to identify them. Decades later, these phenomena were interpreted by two members of the Swedish UFO movement, Erland Sandqvist and Gösta Rehn, as alien spaceships, or UFOs. Rehn argued that ‘[t]here is nothing so dramatic in the Swedish history of UFOs as this invasion of alien fly-things’ (Rehn 1969: 50). In this article the interpretation of such sightings proposed by these authors, namely that we are visited by extraterrestrials from outer space, is approached from the perspective of myth theory. According to this mythical theme, not only are we are not alone in the universe, but also the history of humankind has been shaped by encounters with more highly-evolved alien beings. In their modern day form, these kinds of ideas about aliens and UFOs originated in the United States. The reasoning of Sandqvist and Rehn exemplifies the localization process that took place as members of the Swedish UFO movement began to produce their own narratives about aliens and UFOs. The question I will address is: in what ways do these stories change in new contexts? Texts produced by the Swedish UFO movement are analyzed as a case study of this process.

THE USE OF CASE STUDY METHOD IN TEACHING THE TERMINOLOGY IN THE FIELD OF AGRICULTURAL MACHINERY

2019 ◽  
pp. 123-130
Keyword(s):  
Case Studies ◽  
High Performance ◽  
Mechanical Engineering ◽  
The United States ◽  
Machine Building ◽  
Soil Tillage ◽  
Case Study Method ◽  
Agricultural Machine ◽  
Manufacturing Machine

The scientific research works concerning the field of mechanical engineering such as, manufacturing machine slate, soil tillage, sowing and harvesting based on the requirements for the implementation of agrotechnical measures for the cultivation of plants in its transportation, through the development of mastering new types of high-performance and energy-saving machines in manufacturing machine slate, creation of multifunctional machines, allowing simultaneous soil cultivation, by means of several planting operations, integration of agricultural machine designs are taken into account in manufacturing of the local universal tractor designed basing on high ergonomic indicators. For this reason, this article explores the use of case studies in teaching agricultural terminology by means analyzing the researches in machine building. Case study method was firstly used in 1870 in Harvard University of Law School in the United States. Also in the article, we give the examples of agricultural machine-building terms, teaching terminology and case methods, case study process and case studies method itself. The research works in the field of mechanical engineering and the use of case studies in teaching terminology have also been analyzed. In addition, the requirements for the development of case study tasks are given in their practical didactic nature. We also give case study models that allow us analyzing and evaluating students' activities.

Sign in / Sign up

Export Citation Format

Share Document