scholarly journals A Network of Type III Bricard Linkages

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Shengnan Lu ◽  
Dimiter Zlatanov ◽  
Xilun Ding ◽  
Matteo Zoppi ◽  
Simon D. Guest
Keyword(s):  
Case Studies ◽  
Geometric Parameters ◽  
Degree Of Freedom ◽  
Regular Hexagon ◽  
Analysis And Design ◽  
Type Iii ◽  
The Third ◽  
Planar Shape ◽  
Planar Shapes ◽  
Parameter Values

Among Bricard's overconstrained 6R linkages, the third type has two collapsed configurations, where all joint axes are coplanar. This paper presents a one-degree-of-freedom network of such linkages. Using the two coplanar states of the constituent Bricard units, the network is able to cover a large surface with a specific outline when deployed and can be folded compactly into a stack of much smaller planar shapes. Five geometric parameters describing each type III Bricard mechanism are introduced. Their influence on the outline of one collapsed configuration is discussed and inverse calculation to obtain the parameter values yielding a desired planar shape is performed. The network is built by linking the units, either using scissor linkage elements, if the thickness of the panels can be ignored, or with hinged parallelograms, for a thicker material. Two case studies, in which the Bricard network deploys as a rectangle and a regular hexagon, respectively, are presented, validating the analysis and design methods.

scholarly journals A Network of Type III Bricard Linkages

2015 ◽  
Author(s):  
Shengnan Lu ◽  
Dimiter Zlatanov ◽  
Xilun Ding ◽  
Matteo Zoppi ◽  
Simon D. Guest
Keyword(s):  
Case Studies ◽  
Geometric Parameters ◽  
Degree Of Freedom ◽  
Regular Hexagon ◽  
Analysis And Design ◽  
Type Iii ◽  
The Third ◽  
Planar Shape ◽  
Planar Shapes ◽  
Parameter Values

Among Bricard’s overconstrained 6R linkages, the third type has two collapsed configurations, where all joint axes are coplanar. The paper presents a one-degree-of-freedom network of such linkages. Using the two coplanar states of the constituent Bricard units, the network is able to cover a large surface with a specific outline when deployed, and can be folded compactly into a stack of much smaller planar shapes. Five geometric parameters describing each type III Bricard mechanism are introduced. Their influence on the outline of one collapsed configuration is discussed and inverse calculation to obtain the parameter values yielding a desired planar shape is performed. The network is built by linking the units, either using scissor linkage elements, if the thickness of the panels can be ignored, or with hinged parallelograms, for a thicker material. Two case studies, in which the Bricard network deploys as a rectangle and a regular hexagon, respectively, are presented, validating the analysis and design methods.

Approximation of Cylindrical Surfaces With Deployable Bennett Networks

2016 ◽  
Author(s):  
Shengnan Lu ◽  
Dimiter Zlatanov ◽  
Xilun Ding
Keyword(s):  
Modeling And Simulation ◽  
Case Studies ◽  
Cylindrical Surface ◽  
Kinematic Analysis ◽  
Geometric Parameters ◽  
Degree Of Freedom ◽  
Curved Surfaces ◽  
Deployable Structures ◽  
Elliptical Cylinders ◽  
Insight Into

This paper presents a one-degree-of-freedom network of Bennett linkages which can be deployed to approximate a cylindrical surface. The geometry of the unit mechanism is parameterized and its position kinematics is solved. The influence of the geometric parameters on the deployed shape is examined. Further kinematic analysis isolates those Bennett geometries for which a cylindrical network can be constructed. The procedure for connecting the unit mechanisms in a deployable cylinder is described in detail and used to gain insight into, and formulate some general guidelines for, the design of linkage networks which unfold as curved surfaces. Case studies of deployable structures in the shape of circular and elliptical cylinders are presented. Modeling and simulation validate the proposed approach.

Approximation of Cylindrical Surfaces With Deployable Bennett Networks

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Shengnan Lu ◽  
Dimiter Zlatanov ◽  
Xilun Ding
Keyword(s):  
Modeling And Simulation ◽  
Case Studies ◽  
Cylindrical Surface ◽  
Kinematic Analysis ◽  
Geometric Parameters ◽  
Degree Of Freedom ◽  
Curved Surfaces ◽  
Deployable Structures ◽  
Elliptical Cylinders ◽  
Insight Into

This paper presents a one-degree-of-freedom network of Bennett linkages which can be deployed to approximate a cylindrical surface. The geometry of the unit mechanism is parameterized and its position kinematics is solved. The influence of the geometric parameters on the deployed shape is examined. Further kinematic analysis isolates those Bennett geometries for which a cylindrical network can be constructed. The procedure for connecting the unit mechanisms in a deployable cylinder is described in detail and used to gain insight into, and formulate some general guidelines for, the design of linkage networks which unfold as curved surfaces. Case studies of deployable structures in the shape of circular and elliptical cylinders are presented. Modeling and simulation validate the proposed approach.

NEW TECHNOLOGIES AND PRACTICES FOR WASTE MINIMIZATION IN THE CHEMICAL AND PETROCHEMICAL INDUSTRIES : FINDINGS OF THE SALVADOR, BRAZIL, 1993 CONFERENCE

1994 ◽  
Vol 30 (3) ◽  
pp. 1-9
Author(s):  
Francisco Fontes Lima ◽  
Francisco Alves Pereira
Keyword(s):  
Waste Management ◽  
Environmental Protection ◽  
Case Studies ◽  
New Technologies ◽  
Waste Minimization ◽  
Source Control ◽  
International Conference ◽  
The Third ◽  
Control Programmes ◽  
Petrochemical Industries

This paper describes the findings of the “Third International Conference on Waste Management in the Chemical and Petrochemical Industries,” held in Salvador, Brazil, October 20-23, 1993. A summary of the 74 technical papers, divided into six major categories, is presented together with comments on the more stringent legislation concerning source control programmes. Case studies of two large chemical complexes that have been developing successful waste minimization programmes are described in detail: CETREL-Environmental Protection Company in Camaçari, Brazil, and BASF AG in Ludwigshafen, Germany.

Conclusion

2018 ◽  
Author(s):  
John West
Keyword(s):  
Eighteenth Century ◽  
Case Studies ◽  
Literary History ◽  
The Political ◽  
The Third ◽  
Religious Differences

Literary history often positions Dryden as the precursor to the great Tory satirists of the eighteenth century, like Pope and Swift. Yet a surprising number of Whig writers expressed deep admiration for Dryden, despite their political and religious differences. They were particularly drawn to the enthusiastic dimensions of his writing. After a short reading of Dryden’s poem to his younger Whig contemporary William Congreve, this concluding chapter presents three case studies of Whig writers who used Dryden to develop their own ideas of enthusiastic literature. These three writers are Elizabeth Singer Rowe, John Dennis, and the Third Earl of Shaftesbury. These case studies are used to critique the political polarizations of seventeenth- and eighteenth-century literary history and to stress instead how literary friendship crossed political allegiances, and how writers of differing ideological positions competed to control mutually appealing ideas and vocabularies.

A Social Sonic Paradigm

2021 ◽  
pp. 540-554
Author(s):  
Tegan Bristow ◽  
João Orecchia Zúñiga
Keyword(s):  
Case Studies ◽  
Southern Africa ◽  
Political Engagement ◽  
Sound Art ◽  
Intellectual Engagement ◽  
The Third ◽  
Primary Focus ◽  
Definition Of ◽  
Forms Of Knowledge

This chapter presents an examination of why—in contemporary Africa, with Southern Africa as the primary focus—there are very few artists working with sound in a manner that fits the paradigm of sound art as it is known in Euro-America. Emphasis is not placed on a lack of intellectual engagement, which is significant in the Euro-American definition of sound art. What is presented does not aim to deviate from this, but rather acts to affirm an engagement with alternative forms of knowledge and mechanisms of sound found in the South. Three areas are explored; these however are interlinked and do not stand alone. The first is an understanding of the practice of interdisciplinarity as political engagement. The second explores the role of community and communal interaction with sound and how this is fundamental to form in the region. The third extends this by showing how the histories of knowledge and power are fundamental to these explorations in the region, emphasizing how contemporary explorations of sound are used to both contain and shift these histories. The chapter takes shape with the use of case studies and draws on interviews conducted by the authors.

scholarly journals Public and Private Ownership in the Iranian Constitution: Principle 44, A Barrier for Development

2017 ◽  
Vol 10 (4) ◽  
pp. 73
Author(s):  
Ahmad Torabi
Keyword(s):  
Case Studies ◽  
Economic Impacts ◽  
Private Ownership ◽  
Public Ownership ◽  
Public And Private ◽  
The Third ◽  
Public Property ◽  
Legal Challenges ◽  
The Law ◽  
The Government

The Iranian legislator has sought to protect public property and public ownership in the Iranian Constitution in accordance with Islamic principles, terms and procedures. There are a number of principles that have been directly applied to this purpose; however, one principle has had a very significant impact on government domination of the economy of Iran: principle 44. This principle does not directly describe public property; rather, it aims to determine the areas that are under public ownership and are administered by the government. However, the principle has some contradictions and legal challenges in itself. In addition, the supplementary law that has been enacted to provide the areas for the enforcement of principle 44 fails to secure the aims of the legislator. Therefore, this paper analyses legal challenges of the principle, as well as its supplementary law, and gives suggestions to solve the challenges.This paper is divided into four sections. The first section provides an analysis of the principle itself, and its relationship and consistency with other principles of the constitution. In the second section, the Law of Implementation of Principle 44 and the legal challenges that arise from it will be discussed. The third section focuses on the negative economic impacts of this law, as well as case studies of it. Lastly, the paper provides a summary of suggestions to amend this law.

Naturalized Aesthetics and Emotion Theory

Projections ◽  
2018 ◽  
Vol 12 (2) ◽  
pp. 76-85 ◽  
Author(s):  
Rainer Reisenzein
Keyword(s):  
Empirical Evidence ◽  
Case Studies ◽  
Integrated System ◽  
Third Culture ◽  
Extended Version ◽  
Basic Emotions ◽  
The Third ◽  
Psychological Theories ◽  
Concrete Application ◽  
Emotion Theory

Murray Smith’s proposal in Film, Art, and the Third Culture for a naturalized aesthetics is of interest to both film theorists and psychologists: for the former, it helps to elucidate how films work; for the latter, it provides concrete application cases of psychological theories. However, there are reasons for believing that the theory of emotions that Smith has adopted from psychology to ground his case studies—an extended version of basic emotions theory—is less well supported than he suggests. The available empirical evidence seems more compatible with the assumption that the different emotions are outputs of a single, integrated system.

A Novel Method for Constructing Multi-Mode Deployable Polyhedron Mechanisms Using Symmetric Spatial RRR Compositional Units

2018 ◽  
Author(s):  
Jieyu Wang ◽  
Xianwen Kong
Keyword(s):  
Kinematic Chain ◽  
Degree Of Freedom ◽  
Single Loop ◽  
Kinematic Chains ◽  
The Third ◽  
Motion Modes ◽  
3D Printed ◽  
Novel Method ◽  
Multi Mode ◽  
Motion Mode

A novel construction method is proposed to construct multimode deployable polyhedron mechanisms (DPMs) using symmetric spatial RRR compositional units, a serial kinematic chain in which the axes of the first and the third revolute (R) joints are perpendicular to the axis of the second R joint. Single-loop deployable linkages are first constructed using RRR units and are further assembled into polyhedron mechanisms by connecting single-loop kinematic chains using RRR units. The proposed mechanisms are over-constrained and can be deployed through two approaches. The prism mechanism constructed using two Bricard linkages and six RRR limbs has one degree-of-freedom (DOF). When removing three of the RRR limbs, the mechanism obtains one additional 1-DOF motion mode. The DPMs based on 8R and 10R linkages also have multiple modes, and several mechanisms are variable-DOF mechanisms. The DPMs can switch among different motion modes through transition positions. Prototypes are 3D-printed to verify the feasibility of the mechanisms.

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