scholarly journals Influence of environmental stability on the regulation of end-point impedance during the maintenance of arm posture

2013 ◽  
Vol 109 (4) ◽  
pp. 1045-1054 ◽  
Author(s):  
Matthew A. Krutky ◽  
Randy D. Trumbower ◽  
Eric J. Perreault
Keyword(s):  
Fundamental Difference ◽  
Environmental Stability ◽  
Static Component ◽  
End Point ◽  
Stiffness Properties ◽  
Postural Tasks ◽  
Posture Maintenance ◽  
Selective Increase

Many common tasks compromise arm stability along specific directions. Such tasks can be completed only if the impedance of the arm is sufficient to compensate for the destabilizing effects of the task. During movement, it has been demonstrated that the direction of maximal arm stiffness, the static component of impedance, can be preferentially increased to compensate for directionally unstable environments. In contrast, numerous studies have shown that such control is not possible during postural tasks. It remains unknown if these findings represent a fundamental difference in the control of arm mechanics during posture and movement or an involuntary response to the destabilizing environments used in the movement studies but not yet tested during posture maintenance. Our goal was to quantify how arm impedance is adapted during postural tasks that compromise stability along specific directions. Our results demonstrate that impedance can be modulated to compensate for these instabilities during postural tasks but that the changes are modest relative to those previously reported during reaching. Our observed changes were primarily in the magnitude of end-point stiffness, but these were not sufficient to alter the direction of maximal stiffness. Furthermore, there were no substantial changes in the magnitude of end-point viscosity or inertia, suggesting that the primary change to arm impedance was a selective increase in stiffness to compensate for the destabilizing stiffness properties of the environment. We suggest that these modest changes provide an initial involuntary response to destabilizing environments prior to the larger changes that can be affected through voluntary interventions.

Physical, Chemical, and Crystallographic Characterization of Anodic Coatings on High Strength Aluminum Base Alloys

1976 ◽  
Vol 34 ◽  
pp. 636-637
Author(s):  
R. E. Herfert ◽  
N. T. McDevitt
Keyword(s):  
Sulfuric Acid ◽  
Salt Spray ◽  
High Strength ◽  
Environmental Stability ◽  
Anodic Films ◽  
Sodium Dichromate ◽  
Corrosion Resistant ◽  
Aerospace Applications ◽  
Bond Strengths ◽  
Adhesive Bonded Joints

Durability of adhesive bonded joints in moisture and salt spray environments is essential to USAF aircraft. Structural bonding technology for aerospace applications has depended for many years on the preparation of aluminum surfaces by a sulfuric acid/sodium dichromate (FPL etch) treatment. Recently, specific thin film anodizing techniques, phosphoric acid, and chromic acid anodizing have been developed which not only provide good initial bond strengths but vastly improved environmental durability. These thin anodic films are in contrast to the commonly used thick anodic films such as the sulfuric acid or "hard" sulfuric acid anodic films which are highly corrosion resistant in themselves, but which do not provide good initial bond strengths, particularly in low temperature peel.The objective of this study was to determine the characteristics of anodic films on aluminum alloys that make them corrosion resistant. The chemical composition, physical morphology and structure, and mechanical properties of the thin oxide films were to be defined and correlated with the environmental stability of these surfaces in humidity and salt spray. It is anticipated that anodic film characteristics and corrosion resistance will vary with the anodizing processing conditions.

End Point

2020 ◽  
Author(s):  
Keyword(s):  
End Point

Settler Colonialism and the Revolutionary War

2019 ◽  
Vol 41 (4) ◽  
pp. 7-35
Author(s):  
Andrea Lynn Smith
Keyword(s):  
New York ◽  
Settler Colonialism ◽  
Revolutionary War ◽  
The State ◽  
The Public ◽  
150Th Anniversary ◽  
End Point ◽  
Indian Land ◽  
Indian Relations ◽  
Major General

The centerpiece of New York State’s 150th anniversary of the Sullivan Expedition of 1779 was a pageant, the “Pageant of Decision.” Major General John Sullivan’s Revolutionary War expedition was designed to eliminate the threat posed by Iroquois allied with the British. It was a genocidal operation that involved the destruction of over forty Indian villages. This article explores the motivations and tactics of state officials as they endeavored to engage the public in this past in pageant form. The pageant was widely popular, and served the state in fixing the expedition as the end point in settler-Indian relations in New York, removing from view decades of expropriations of Indian land that occurred well after Sullivan’s troops left.

Simplified Approach to Calculating Geometric Stiffness Properties of Tread Pattern Elements

2003 ◽  
Vol 31 (3) ◽  
pp. 132-158 ◽  
Author(s):  
R. E. Okonieski ◽  
D. J. Moseley ◽  
K. Y. Cai
Keyword(s):  
Development Process ◽  
Functional Design ◽  
Simplified Approach ◽  
Tire Industry ◽  
Geometric Stiffness ◽  
Stiffness Properties ◽  
Engineering Parameters ◽  
Net To Gross ◽  
Significant Effort

Abstract The influence of tread designs on tire performance is well known. The tire industry spends significant effort in the development process to create and refine tread patterns. Creating an aesthetic yet functional design requires characterization of the tread design using many engineering parameters such as stiffness, moments of inertia, principal angles, etc. The tread element stiffness is of particular interest because of its use to objectively determine differences between tread patterns as the designer refines the design to provide optimum levels of performance. The tread designer monitors the change in stiffness as the design evolves. Changes to the geometry involve many attributes including the number of sipes, sipe depth, sipe location, block element edge taper, nonskid depth, area net-to-gross, and so forth. In this paper, two different formulations for calculating tread element or block stiffness are reviewed and are compared to finite element results in a few cases. A few simple examples are shown demonstrating the basic functionality that is possible with a numerical method.

Is Style of Reasoning a Fundamental Difference Between the Common Law and the Civil Law?

2017 ◽  
Vol 17 (2) ◽  
pp. 238-290
Author(s):  
Colm Peter McGrath ◽  
◽  
Helmut Koziol ◽  
Keyword(s):  
Common Law ◽  
Civil Law ◽  
Fundamental Difference ◽  
The Common

Yu.F. Samarin’s Model of the National State: Between Archaic and Modern

2019 ◽  
Vol 54 ◽  
pp. 149-155
Author(s):  
Alexey B. Panchenko
Keyword(s):  
Rural Community ◽  
Fundamental Difference ◽  
The State ◽  
Basic Unit ◽  
National State ◽  
Basic Model ◽  
The Face ◽  
Identical Position ◽  
Ethnocultural Community ◽  
Communicative Space

Yu. F. Samarin’s works are traditionally viewed through the prism of his affiliation with Slavophilism. His view of the state is opposed to the idea of the complex empire based on unequal interaction of the central power with the elite of national districts. At the same time it was important for Samarin to see the nation not as an ethnocultural community, but as classless community of equal citizens, who were in identical position in the face of the emperor. Samarin’s attitude to religion and nationality had pragmatic character and were understood as means for the creation of the uniform communicative space inside the state. This position for the most part conformed with the framework of the national state basic model, however there still existed one fundamental difference. Samarin considered not an individual, but the rural community that owned the land, to be the basic unit of the national state. As the result the model of national state was viewed as the synthesis of modernistic (classlessness, pragmatism, equality) and archaic (communality) features.

TRANSFORMASI DIALEKTIKA SEGITIGA: POSISI DAN PERAN DALAM KAJIAN INTEGRASI AGAMA, SAINS, DAN TEKNOLOGI

1970 ◽  
Vol 19 (2) ◽  
pp. 314-333
Author(s):  
Sarno Hanipudin
Keyword(s):  
Research Methods ◽  
Science And Religion ◽  
Fundamental Difference ◽  
Material Objects ◽  
Religion And Science ◽  
Empirically Supported

This paper is intended to describe how the integration of religion and science is done through the practice of PAI learning. This was done because there is a strong presumption in the wider community who say that religion and science are the two entities that can not be met. Both have their respective territories, separated from each other, in terms of formal-material objects, research methods, criteria of truth, the role played by scientists. There is also a view that science and religion stand at their respective position, because science rely on empirically supported data to ascertain what is real and what is not, contrary religion ready to accept the supernatural and certainly not only be based on tangible variables of faith and the belief that religion and science must coexist independently of each other, because even though there are similarities in their mission, the fundamental difference between the two present a conflict that will resonate on each core. Tulisan ini ditujukan untuk mendeskripsikan bagaimana integrasi agama dan sains dilakukan melalui praktik pembelajaran PAI. Hal itu dilakukan karena ada anggapan yang kuat dalam masyarakat luas yang mengatakan bahwa agama dan ilmu adalah dua entitas yang tidak dapat dipertemukan. Keduanya mempunyai wilayah masing-masing, terpisah antara satu dan lainnya, baik dari segi objek formalmaterial, metode penelitian, kriteria kebenaran, peran yang dimainkan oleh ilmuwan. Ada juga yang memandang bahwa sains dan agama berdiri pada posisinya masingmasing, karena bidang ilmu mengandalkan data yang didukung secara empiris untuk memastikan apa yang nyata dan apa yang tidak, agama sebaliknya siap menerima yang gaib dan tidak pasti hanya didasarkan pada variabel berwujud dari iman dan kepercayaan bahwa agama dan sains harus hidup berdampingan independen satu sama lain, sebab meskipun ada kesamaan dalam misi mereka, perbedaan mendasar antarakeduanya menyajikan sebuah konflik yang akan beresonansi pada inti masingmasing.

Sign in / Sign up

Export Citation Format

Share Document