scholarly journals Dividing-Wall Column Design: Analysis of Methodologies Tailored to Process Simulators

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1189
Author(s):  
Gloria A. Buitimea-Cerón ◽  
Juergen Hahn ◽  
Nancy Medina-Herrera ◽  
Arturo Jiménez-Gutiérrez ◽  
José A. Loredo-Medrano ◽  
...  
Keyword(s):  
Case Studies ◽  
Structural Design ◽  
Design Procedure ◽  
The Other ◽  
Preliminary Design ◽  
Dividing Wall Column ◽  
Operating Variables ◽  
Design Variables ◽  
Column Design ◽  
Proposed Modification

Dividing-wall columns (DWCs) are intensified processes that have attracted industrial and academic attention due to the reduction in operating and installation costs compared to traditional distillation systems. Several methodologies are available for the design of DWCs. Most of them consist of three parts: an analysis of operating variables; an analysis of the structural design (topology); and an optimization of the resulting preliminary design. This paper aims to study three widely used design methodologies reported in the literature for DWCs, i.e., Triantafyllou and Smith (T&S), minimum vapor (Vmin), and Sotudeh and Shahraki (S&S) methods, along with their implementation on process simulators. A proposed modification to the S&S methodology is also presented. A comparison of the methods is carried out and rated against designs with minimum total annual costs. The analysis considers the effect of different structural design variables to initialize the design procedure with each methodology. Five case studies involving mixtures with different ease of separation index were evaluated. The results show that the most efficient techniques were obtained with a modified Sotudeh and Shahraki’s methodology. It was also found that the T&S approach stands out from the other methods, as it provided excellent initial designs for the case studies tested in this work.

A feasible path-based approach for Dividing Wall Column design procedure

2021 ◽  
Vol 149 ◽  
pp. 107309
Author(s):  
Alessandro Di Pretoro ◽  
Flavia Ciranna ◽  
Matteo Fedeli ◽  
Xavier Joulia ◽  
Ludovic Montastruc ◽  
...  
Keyword(s):  
Design Procedure ◽  
Dividing Wall Column ◽  
Column Design ◽  
Feasible Path

The Propaganda Feedback Loop

2018 ◽  
Author(s):  
Yochai Benkler ◽  
Robert Faris ◽  
Hal Roberts
Keyword(s):  
Case Studies ◽  
Feedback Loop ◽  
The Other ◽  
Hillary Clinton ◽  
Donald Trump ◽  
The Public ◽  
False Reporting ◽  
Media Ecosystem ◽  
Crowd Out ◽  
Selection Of

This chapter presents a model of the interaction of media outlets, politicians, and the public with an emphasis on the tension between truth-seeking and narratives that confirm partisan identities. This model is used to describe the emergence and mechanics of an insular media ecosystem and how two fundamentally different media ecosystems can coexist. In one, false narratives that reinforce partisan identity not only flourish, but crowd-out true narratives even when these are presented by leading insiders. In the other, false narratives are tested, confronted, and contained by diverse outlets and actors operating in a truth-oriented norms dynamic. Two case studies are analyzed: the first focuses on false reporting on a selection of television networks; the second looks at parallel but politically divergent false rumors—an allegation that Donald Trump raped a 13-yearold and allegations tying Hillary Clinton to pedophilia—and tracks the amplification and resistance these stories faced.

scholarly journals Ethnic Hatred and Universal Benevolence: Ethnicity and Loyalty in Precolonial Myanmar, and Britain

2021 ◽  
Vol 63 (2) ◽  
pp. 310-338
Author(s):  
Victor Lieberman
Keyword(s):  
Case Studies ◽  
Political Thought ◽  
Western Europe ◽  
Popular Sovereignty ◽  
The Other ◽  
Social Pressures ◽  
Legal Equality ◽  
The One

AbstractInsisting on a radical divide between post-1750 ideologies in Europe and earlier political thought in both Europe and Asia, modernist scholars of nationalism have called attention, quite justifiably, to European nationalisms’ unique focus on popular sovereignty, legal equality, territorial fixity, and the primacy of secular over universal religious loyalties. Yet this essay argues that nationalism also shared basic developmental and expressive features with political thought in pre-1750 Europe as well as in rimland—that is to say outlying—sectors of Asia. Polities in Western Europe and rimland Asia were all protected against Inner Asian occupation, all enjoyed relatively cohesive local geographies, and all experienced economic and social pressures to integration that were not only sustained but surprisingly synchronized throughout the second millennium. In Western Europe and rimland Asia each major state came to identify with a named ethnicity, specific artifacts became badges of inclusion, and central ethnicity expanded and grew more standardized. Using Myanmar and pre-1750 England/Britain as case studies, this essay reconstructs these centuries-long similarities in process and form between “political ethnicity,” on the one hand, and modern nationalism, on the other. Finally, however, this essay explores cultural and material answers to the obvious question: if political ethnicities in Myanmar and pre-1750 England/Britain were indeed comparable, why did the latter realm alone generate recognizable expressions of nationalism? As such, this essay both strengthens and weakens claims for European exceptionalism.

scholarly journals Zero-Tolerance in Catalonia: Policing the Other in Public Space

2020 ◽  
Author(s):  
Martin Lundsteen ◽  
Miquel Fernández González
Keyword(s):  
Public Space ◽  
Case Studies ◽  
Urban Space ◽  
Zero Tolerance ◽  
The Other ◽  
Social Effects ◽  
Main Argument ◽  
Sociocultural Practices

AbstractRecent studies have argued for more nuanced understandings of zero tolerance (ZT) policing, rendering it essential to analyze the significance and actual workings of the policies in practice, including the context in which they are introduced. This article aims to accomplish this through a comparison of two case studies in Catalonia: one in the neighborhood of Raval in Barcelona and one in Salt—a municipality in the comarca (or county) of Girona. We identify a transformation in the use of ZT policies in Catalonia and a contradiction between their social effects and proclaimed objectives. This article attempts to address how specific sociocultural groups gain power and privilege from these policies. The main argument is that a set of commonsensical ideas have become hegemonic, which allows and naturalizes certain sociocultural practices in urban space, while persecuting others, fundamentally pitting two categories against each other: the desired civil citizen and the undesirable and uncivil stranger.

Study on Wear-Preventing of Needle Valve in Fuel Injection System Mounted on DME Engine

2011 ◽  
Vol 228-229 ◽  
pp. 1057-1062
Author(s):  
Xin Rong Wen ◽  
Guang De Zhang ◽  
Wei Hua Wang ◽  
Xie Lu ◽  
Sun Jing
Keyword(s):  
Dynamic Stability ◽  
Structural Design ◽  
Fuel Injection ◽  
Dynamic Instability ◽  
Calculation Model ◽  
The Other ◽  
Injection System ◽  
Needle Valve ◽  
Fuel Injection System ◽  
Theoretical Support

The purpose of this paper is to provide theoretical support for the structural design to prevent the wear of needle. The actual wear of the orientation part of the needle in scrapped needles was researched. The presented results showed that the main reason to the wear of the orientation part of needle was the dynamic instability and the abrasives enter into the surface of orientation part which increases the wear, and that the calculation model of dynamic stability was proposed to prevent the wear of needle. This model was a pressure rod, one end of which was fixed, the other was free, and the two ends were pressed on axial force which changes with time. Besides, the classic formula of dynamic stability of pressure rod was changed rationally, so as to correspond with the calculation model. It will play a part in preventing the wear of needle.

Recent Developments in Composite Construction in the USA

2005 ◽  
Vol 8 (3) ◽  
pp. 259-274 ◽  
Author(s):  
Roberto T. Leon
Keyword(s):  
Reinforced Concrete ◽  
Design Procedure ◽  
Concrete Columns ◽  
Short Description ◽  
Smooth Transition ◽  
American Institute ◽  
Recent Developments ◽  
The Usa ◽  
Column Design ◽  
Main Change

This paper presents an overview of the proposed changes in composite design provisions for the upcoming American Institute of Steel Construction (AISC) 2005 Specification. The main change insofar as member design is concerned relates to how composite column design is handled. The new provisions will provide a more smooth transition between design of composite and reinforced concrete columns and a more rational, mechanistically-based design procedure. Insofar as member detailing is concerned, the main change is in the strength values for shear studs, which have been considerably lowered under some circumstances. The paper also presents some ongoing developments in composite floor and lateral load resisting systems, and concludes with a short description of an unusual composite truss.

Bending Stiffener Design Through Structural Optimization

2009 ◽  
Author(s):  
Rafael Loureiro Tanaka ◽  
Lauro Massao Yamada da Silveira ◽  
Joa˜o Paulo Zi´lio Novaes ◽  
Eduardo Esterqui de Barros ◽  
Clo´vis de Arruda Martins
Keyword(s):  
Optimization Problem ◽  
Design Procedure ◽  
Complex Task ◽  
Load Case ◽  
Shear Forces ◽  
Design Variables ◽  
Curvilinear Coordinate ◽  
Regular Design ◽  
Curvature Deformation ◽  
Flexible Risers

Bending stiffeners are very important ancillary equipments of umbilicals or flexible risers, since they protect the lines from overbending. Their design however is a complex task, since many load cases must be taken into account; the structure itself has a section that is variable with curvilinear coordinate. To aid the designer in this task, optimization algorithms can be used to automate the search for the best design. In this work an optimization algorithm is applied to the design of the bending stiffener. First, a bending stiffener model is created, which is capable of simulating different load case conditions and provide, as output, results of interest such as maximum curvature, deformation along the stiffener, shear forces and so on. Then, a bending stiffener design procedure is written as an optimization problem and, for that, objective function, restrictions and design variables defined. Study cases were performed, comparing a regular design with its optimized counterpart, under varying conditions.

Influencing travel behaviour

2019 ◽  
pp. 107-130
Author(s):  
Stewart Barr ◽  
John Preston
Keyword(s):  
Qualitative Study ◽  
Case Studies ◽  
Behaviour Change ◽  
Social Marketing ◽  
Quantitative Study ◽  
Behavioural Change ◽  
Travel Behaviour ◽  
Air Travel ◽  
The Other ◽  
Car Travel

As travel planning’s theoretical underpinnings have broadened from engineering and economics to embrace psychology and sociology, an emphasis has been placed on social marketing and nudge theory. It is argued that this is consistent with a neo-liberal trend towards governing from a distance. Using two case studies, one a qualitative study of reducing short-haul air travel, the other a quantitative study of attempts to reduce local car travel, it is found that actual behaviour change is limited. This seems to arise because behavioural change has been too narrowly defined and overly identified with personal choice.

Policy and Practice: An Overview

1990 ◽  
Vol 12 (3) ◽  
pp. 233-239 ◽  
Author(s):  
David K. Cohen ◽  
Deborah Loewenberg Ball
Keyword(s):  
Case Studies ◽  
Classroom Practice ◽  
Teaching And Learning ◽  
Early Report ◽  
State Policies ◽  
The Other ◽  
Special Issue ◽  
Policy And Practice ◽  
School Practices ◽  
The One

Policymakers in the U. S. have been trying to change schools and school practices for years. Though studies of such policies raise doubts about their effects, the last decade has seen an unprecedented increase in state policies designed to change instructional practice. One of the boldest and most comprehensive of these has been undertaken in California, where state policymakers have launched an ambitious effort to improve teaching and learning in schools. We offer an early report on California's reforms, focusing on mathematics. State officials have been promoting substantial changes in instruction designed to deepen students' mathematical understanding, to enhance their appreciation of mathematics and to improve their capacity to reason mathematically. If successful, these reforms would be a sharp departure from existing classroom practice, which attends chiefly to computational skills. The research reported here focuses on teachers' early responses to the state's efforts to change mathematics instruction. The case studies of five teachers highlight a key dilemma in such ambitious reforms. On the one hand, teachers are seen as the root of the problem: their instruction is mechanical, often boring, and superficial. On the other hand, teachers are cast as the key agents of improvement because students will not learn the new mathematics that policymakers intend unless teachers learn that math and teach it. But how can teachers teach a mathematics that they never learned, in ways they never experienced? That is the question explored in this special issue.

Aerodynamic and structural design for the development of a MALE UAV

2018 ◽  
Vol 90 (7) ◽  
pp. 1077-1087 ◽  
Author(s):  
Pericles Panagiotou ◽  
Efstratios Giannakis ◽  
Georgios Savaidis ◽  
Kyros Yakinthos
Keyword(s):  
Structural Design ◽  
Design Procedure ◽  
Unmanned Aircraft ◽  
Content Type ◽  
Parameterized Design ◽  
Detail Design ◽  
Aerial Vehicle ◽  
Structural Parts ◽  
Long Endurance ◽  
Structural Aspects

Purpose The purpose of this paper is to present the preliminary design of a medium altitude long endurance (MALE) unmanned aerial vehicle (UAV), focusing on the interaction between the aerodynamic and the structural design studies. Design/methodology/approach The classic layout theory was used, adjusted for the needs of unmanned aircraft, including aerodynamic calculations, presizing methods and CFD, to estimate key aerodynamic and stability coefficients. Considering the structural aspects, a combination of layout, finite element methods and custom parameterized design tools were used, allowing automatic reshapes of the skin and the internal structural parts, which are mainly made of composite materials. Interaction loops were defined between the aforementioned studies to optimize the performance of the aerial vehicle, maximize the aerodynamic efficiency and reduce the structural weight. Findings The complete design procedure of a UAV is shown, starting from the final stages of conceptual design, up to the point where the detail design and mechanical drawings initiated. Practical implications This paper presents a complete view of a design study of a MALE UAV, which was successfully constructed and flight-tested. Originality/value This study presents a complete, synergetic approach between the configuration layout, aerodynamic and structural aspects of a MALE UAV.

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