Mechanical Vibration and Aeroelasticity

1947 ◽  
Vol 51 (436) ◽  
pp. 417-423
Author(s):  
P. B. Walker
Keyword(s):  
Mechanical Vibration ◽  
Common Interest ◽  
Aeronautical Engineering ◽  
The Subject

In his article “The Expanding Domain of Aeroelasticity,” Professor Collar explains how, in the course of a few years, the subject of aeroelasticity has grown from a mere collection of problems of common interest to the aerodynamicist and the structural specialist to become a main branch of aeronautical engineering. Aeronautical engineers owe Professor Collar a debt of gratitude for defining in the clearest terms what aeroelasticity purports to be, and for removing the vagueness and uncertainty which so often permeates any new branch of science or engineering, especially when it is derived from long–established subjects, as aeroelasticity is from aerodynamics and theory of structures.As is to be expected from one so distinguished in the aeroelastic field, Professor Collar writes especially from the standpoint of the aeroelastic specialist. Engineers with a different background, while accepting the broad principles which Professor Collar lays down, may see their applications and development in a different light.

On establishing equations of motion of mechanical vibration systems placed on moving bases

2017 ◽  
Vol 45 (3) ◽  
pp. 209-227
Author(s):  
M Gürgöze ◽  
F Terzioğlu
Keyword(s):  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Mechanical Vibration ◽  
Main Idea ◽  
Vertical Axis ◽  
Constant Angular Velocity ◽  
Vibration System ◽  
Reaction Forces ◽  
The Subject ◽  
Vibrating Systems

The first author has been teaching the postgraduate course, “The Dynamics of Mechanical Systems” in The ITU Faculty of Mechanical Engineering for nearly 20 years. He has observed that students frequently have problems in obtaining the equations of motion of the vibrating systems which were placed on moving bases. Starting from this observation, he has found that the homework stated below, which was given to the students occasionally, was very helpful in learning the subject. The main idea of the homework is the derivation of the equations of motion, with the help of formulating the Lagrange’s equations with respect to a moving set of axis for a vibration system with two degrees of freedom which consists of a horizontal table rotating with a constant angular velocity around a vertical axis. The students were also asked to solve the same problem with a different method of their choice and to determine the reaction forces as well. We want to share this problem with the reader, which we have assessed as very instructive and appropriate from the viewpoint of applicability of different methods.

scholarly journals Multikulturalisme: Analisis Wacana Buku Teks Pelajaran Sejarah

2021 ◽  
Vol 2 (1) ◽  
pp. 17-31
Author(s):  
Agung Syahriman ◽  
Agus Mulyana
Keyword(s):  
High School ◽  
Discourse Analysis ◽  
Critical Discourse Analysis ◽  
School Curriculum ◽  
History Textbooks ◽  
Common Interest ◽  
Historical Event ◽  
History Textbook ◽  
High School Curriculum ◽  
The Subject

This article is a review of the history textbooks of High School that aims to view and analyze the content of multiculturalism material contained in history textbooks. The method used in this study is critical discourse analysis. The subject in this study is Indonesia history textbook class XI High School Curriculum 2013 (Revised 2017). The results of the study showed that there is a content of multiculturalism material contained in textbooks. This can be seen from the achievements of indoctrinators who support multiculturalism as a whole (the value of tolerance, the value of equality, and democratic values). With the appearance of these indicators, it can be said that the Indonesia history textbook class XI curriculum 2013 is enough to display the content of material containing multiculturalism. In addition, withthe ampilnya content of multiculturalism material in historical textbooks, it can be said to be an effort to be able to channel the understanding of multiculturalism to the younger generation (students). The material of multiculturalism itself  is very suitable to be displayed in historical textbook material. Because, history textbooks in addition to being a medium that supports learning, is also a medium that can show learners a historical event that has occurred in the past with many essences and values of diversity that exist. It is a common interest for the formation of attitudes of learners who can respect each other in their lives.   KEYWORDS Multiculturalism, History textbooks, Discourse analysis.

scholarly journals The Rebirth of the Musical Author in Recent Fiction Written in English

Authorship ◽  
2012 ◽  
Vol 1 (2) ◽  
Author(s):  
Carmen Lara-Rallo
Keyword(s):  
Henry James ◽  
Common Interest ◽  
Contemporary Fiction ◽  
General Tendency ◽  
Critical Practice ◽  
Children's Book ◽  
The Subject ◽  
Concert Pianist ◽  
The Way

In his 2005 monograph on The Author, Andrew Bennett reflects on how “authorship is central to the way in which critical practice is currently conceptualized and theorized”. The rebirth of the author in contemporary criticism is being accompanied by a renewed fascination with the figure of the author as the subject of recent fiction. This can be seen reflected in current portrayals of real and fictional writers such as Henry James, in David Lodge’s Author, Author (2004), or Olive Wellwood, in A.S. Byatt’s The Children’s Book (2009). Moreover, the recovery of the author can be traced as well in the context of the emergence of music as a fertile referent for interartistic narratives. In terms of the dialogue between contemporary fiction and music, there seems to be a common interest in the image of the author, both in the act of creation, as a composer, and of re-creation, as a performer. Works such as Bernard MacLaverty’s Grace Notes (1997), Vikram Seth’s An Equal Music (1999), Conrad Williams’ The Concert Pianist (2006), or Kazuo Ishiguro’s Nocturnes. Five Stories of Music and Nightfall (2009) favour the author-musician’s perspective as they interact with music in different ways. In light of this, the aim of this article is to explore the process of rebirth of the musical author in recent fiction written in English, analysing this trend as part of a more general tendency to recover the author’s presence and voice in both fiction and criticism.

Elementary Aspects of Technical Statistics and Common Fallacies

1950 ◽  
Vol 54 (475) ◽  
pp. 464-475
Author(s):  
W. E. Thornton-Bryar
Keyword(s):  
Aeronautical Engineering ◽  
The Subject

The subject of statistics is so vast that many thousands of volumes have been written on it and it would be lunacy to try to give any complete outline in a brief paper. Even by confining the field to that range of data arising from aeronautical engineering the limit seems to recede into specialist abstractions rather than narrow as generality is jettisoned. At the outset it may be well to consider these apparent platitudes because many (most?) otherwise well-informed people are dogmatic in their belief that statistics are merely applied arithmetic. No doubt the same kind of thing was said before any distinction was drawn between a tally-clerk and a qualified accountant. The assertion contains too much fundamental truth for easy rebuttal: nevertheless there does exist both a science and an art in statistics, and arithmetic is only one important contribution to the exercise of either.

Some Considerations on the Present-day Knowledge of Psychiatry, and its Application to those under Care in Public Institutions for the Insane

1924 ◽  
Vol 70 (291) ◽  
pp. 507-519
Author(s):  
M. J. Nolan
Keyword(s):  
Great Difficulty ◽  
Public Institutions ◽  
Common Interest ◽  
The Subject

There is great difficulty in finding a novel theme as the subject of an address to the members of an Association which rejoices in the maturity of its eighty-third year of existence. Still greater is the difficulty in finding a subject of common interest having regard to the varied branches of work covered by their labours, ranging as they do from the busy routine of a crowded day to the silent special research in the laboratory. And the greatest difficulty of all lies in the fact that in each of these fields of work there are many present who have had vastly wider opportunities than I have had, and who could treat their chosen subject with infinitely more skill in thought and language than I can command. Since, however, you have been good enough to give me the opportunity of addressing you I feel you will be no less generous in pardoning my shortcomings on this occasion.

Impulsive Synchronisation: A Conversation on Military Technologies and Audiovisual Arts

2016 ◽  
Author(s):  
Aura Satz ◽  
Jussi Parikka
Keyword(s):  
World War Ii ◽  
Spread Spectrum ◽  
Common Interest ◽  
Historical Discourse ◽  
Secret Communication ◽  
Starting Point ◽  
Female Figures ◽  
Changing Patterns ◽  
The Subject ◽  
Mechanical Music

Stemming from their common interest in media archeology and the idea of the air as a medium of encrypted signals, Satz and Parikka explore the themes emerging from Satz's film installation 'Impulsive Synchronisation' (2013). Satz has used various technologies as the subject of her work, including the Chladni plate, mechanical music, phonograph grooves and optical sound, looking at how such objects tap into ideas of knowledge and communication in their use of notation systems, languages or codes. Satz is also interested in bringing to the fore key female figures largely excluded from mainstream historical discourse in an ongoing engagement with the question of women’s contributions to labour, technology and scientific knowledge. The starting point for ‘Impulsive Synchronisation’ was a 'Secret Communication System' patented during World War II by Hollywood star Hedy Lamarr and American composer George Antheil. This invention of 'frequency hopping', designed to protect radio-controlled torpedoes from enemy disruption by distributing the signal over many frequencies and synchronising the transmitter and receiver in rapidly changing patterns, has become the basis for today's spread-spectrum technology. In Satz’s work, these technologies are referenced to explore visual, musical and data notation, as well as its encryption, synchronisation and decipherment.

The Red Cross and the human environment

1976 ◽  
Vol 16 (183) ◽  
pp. 295-300 ◽  
Author(s):  
Jacques Vigne ◽  
J.-G.L.
Keyword(s):  
United Nations ◽  
Well Being ◽  
Responsibility To Protect ◽  
Common Interest ◽  
Future Generations ◽  
Red Cross ◽  
International Review ◽  
Human Environment ◽  
The Subject ◽  
The United Nations

In the August 1972 issue of International Review, an article on the United Nations Conference on the Human Environment drew attention to one of the vital problems of our day. The importance of the subject was underlined in the seven-paragraph Declaration adopted in Stockholm in June 1972, expressing man's common interest in the preservation of our planet. The Declaration, comprising a preamble and a number of principles, stated, inter alia, the following:Man has the fundamental right to freedom, equality and adequate conditions of life, in an environment of a quality which permits a life of dignity and well-being, and bears a solemn responsibility to protect and improve the environment for present and future generations.

scholarly journals Piezoelectric Particulate Composite for Energy Harvesting from Mechanical Vibration

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4925
Author(s):  
Dariusz Grzybek ◽  
Dariusz Kata ◽  
Wojciech Sikora ◽  
Bogdan Sapiński ◽  
Piotr Micek ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Rectangular Cross Section ◽  
Mechanical Vibration ◽  
Electric Energy ◽  
Particulate Composite ◽  
Piezoelectric Composite ◽  
Main Element ◽  
Beam Structure ◽  
Bending Mode ◽  
The Subject

Energy harvesting from mechanical vibration of buildings is usually realized by the use of devices, in which the main element is a prismatic beam with a rectangular cross-section. The beam has been the subject of scientific research; it is usually constructed with a carrying substrate that does not have piezoelectric characteristics and from piezoelectric material. In contrast, this investigation sought to create a beam structure with a piezoelectric composite only. The entire beam structure was made of a prototype piezoelectric particulate composite. Based on courses of voltage obtained in laboratory experiments and known geometry of the specimens, a series of finite element method (FEM) simulations was performed, aiming to estimate the piezoelectric coefficient d31 value at which the mentioned voltage could be achieved. In each specimen, sedimentation caused the formation of two distinct layers: top and bottom. The experiments revealed that the presented prototype piezoelectric particulate composite converts mechanical stress to electric energy in bending mode, which is used in energy harvesting from mechanical vibration. It is self-supporting and thus a carrying substrate is not required in the harvester structure.

scholarly journals Reducing Service Contract Costs and Do-lt-Yourself EM Maintenance

1997 ◽  
Vol 5 (10) ◽  
pp. 8-9
Author(s):  
Owen P. Mills
Keyword(s):  
Constant Pressure ◽  
Discussion Group ◽  
Common Interest ◽  
Service Contract ◽  
Service Contracts ◽  
The Subject ◽  
Do It Yourself ◽  
Contract Costs

Service contract expenses constitute a large proportion of many EM laboratory budgets each year and managers, under constant pressure to reduce costs, no longer look at the expense as sacred. Increasingly, microscopists are faced with finding alternatives to the full service contracts they enjoyed so long. I facilitated a discussion group at the Microscopy & Microanalysis '97 meeting held recently in Cleveland entitled "EM Maintenance: Can you do it yourself?" The audience of 50 represented microscopists from industry, academic and government facilities with a common interest - learning how to sensibly reduce service contract costs. In this article, I will offer my perspective on the subject and relate issues raised by the audience.

scholarly journals Unconstitutional Change of Government: A New Crime within the Jurisdiction of the African Criminal Court

2017 ◽  
Vol 30 (4) ◽  
pp. 967-986 ◽  
Author(s):  
HARMEN VAN DER WILT
Keyword(s):  
Law Enforcement ◽  
Criminal Court ◽  
Regional Level ◽  
Common Interest ◽  
African Experience ◽  
Foreign Intervention ◽  
Positive Argument ◽  
The Subject ◽  
The Right ◽  
Static Form

AbstractOne of the most interesting and controversial crimes that belong to the subject matter jurisdiction of the newly to be established African Criminal Chamber is undoubtedly the crime of unconstitutional change of government. This article explores the question why this offence is upgraded to the regional level of criminal law enforcement. After all, any criminalization of the conduct at a regional level and the concomitant inclusion of the offence in the jurisdiction of regional courts raises questions about the right of foreign intervention in internal political affairs and the curtailment of the right to rebel. The crime of unconstitutional change of government is tested against these principles and it is concluded that they do not impede criminalization, nor the elevation of the crime to a regional level. In search of a positive argument in defence of the inclusion of the crime within the jurisdiction of the African Court, I contend that the best explanation is that insurgencies are not contained to single states but are inclined to spread to other countries. In view of the specific African experience, where endemic conflicts have proved to be contagious, it is clear that states have a common interest in suppressing both the dynamic and static form of unconstitutional change of government.

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