Towards fractional sensors

2018 ◽  
Vol 25 (1) ◽  
pp. 52-60 ◽  
Author(s):  
António M. Lopes ◽  
J. A. Tenreiro Machado ◽  
Alexandra M. Galhano

This paper proposes a new sensor architecture inspired on the classical accelerometer and the fractional calculus. The fractional sensor (FS) adopts a modular construction with [Formula: see text] stages, where each stage consists of an association of mass–spring–damper elements. A proper selection of the elements in the global mechanical structure yields fractional-order characteristics. The frequency and time responses of the proposed apparatus are studied and compared with those exhibited by an ideal fractional order device. The FS can be implemented by means of modern fabrication techniques used with micro electro-mechanical systems.

2012 ◽  
Vol 22 (5) ◽  
pp. 5-11 ◽  
Author(s):  
José Francisco Gómez Aguilar ◽  
Juan Rosales García ◽  
Jesus Bernal Alvarado ◽  
Manuel Guía

In this paper the fractional differential equation for the mass-spring-damper system in terms of the fractional time derivatives of the Caputo type is considered. In order to be consistent with the physical equation, a new parameter is introduced. This parameter char­acterizes the existence of fractional components in the system. A relation between the fractional order time derivative and the new parameter is found. Different particular cases are analyzed


2013 ◽  
Vol 198 ◽  
pp. 427-432 ◽  
Author(s):  
Andrzej Dymarek ◽  
Tomasz Dzitkowski

The paper presents the problem of vibration reduction in designed discrete mechanical systems. The method of reduction has been based on active synthesis, which makes it possible to obtain the desired mechanical effect through the proper selection of dynamic properties of the system, including the calculation of the active force as a function of the system force feedback.


2013 ◽  
Vol 307 ◽  
pp. 295-298 ◽  
Author(s):  
Tomasz Dzitkowski ◽  
Andrzej Dymarek

The paper presents the problem of stability and vibration reduction in designed discrete mechanical systems. The method of stabilisation and reduction has been based on active synthesis, which makes it possible to obtain the desired mechanical effect through the proper selection of dynamic properties of the system, including the calculation of the active force as a function of the system force feedback.


2017 ◽  
Vol 10 (1) ◽  
pp. 32-52
Author(s):  
Bonnie White

In 1917 the British government began making plans for post-war adjustments to the economy, which included the migration of surplus women to the dominions. The Society for the Overseas Settlement of British Women was established in 1920 to facilitate the migration of female workers to the dominions. Earlier studies have argued that overseas emigration efforts purposefully directed women into domestic service as surplus commodities, thus alleviating the female ‘surplus’ and easing economic hardships of the post-war period. This article argues that as Publicity Officer for the SOSBW, Meriel Talbot targeted women she believed would be ideal candidates for emigration, including former members of the Women's Land Army and affiliated groups. With the proper selection of female migrants, Talbot sought to expand work opportunities for women in the dominions beyond domestic service, while reducing the female surplus at home and servicing the connection between state and empire. Dominion authorities, whose demands for migrant labour vacillated between agricultural workers during the war years and domestic servants after 1920, disapproved of Talbot's efforts to migrate women for work in agriculture. Divergent policies led to the early failure of the SOSBW in 1923.


1972 ◽  
Vol 68 (2_Supplb) ◽  
pp. S44-S73 ◽  
Author(s):  
Eugene F. Bernstein

ABSTRACT Among the critical factors in organ perfusion are (1) the mechanical components of the system, (2) the composition of the perfusate, and (3) the perfusing conditions. In this review, particular consideration is given to the pump, the oxygenator, and cannulas in such systems. Emphasis is placed upon the selection of pertinent equipment for the goals of a particular perfusion experiment, based upon the criteria of adequacy of the perfusion. Common problems in organ perfusion are summarized, and potential solutions to the perfusion problem, involving either biologic or mechanical extracorporeal systems, are suggested.


2011 ◽  
Vol 36 (7) ◽  
pp. 1089 ◽  
Author(s):  
Wei-Chao Chiu ◽  
Chun-Che Chang ◽  
Jiun-Ming Wu ◽  
Ming-Chang M. Lee ◽  
Jia-Min Shieh

Author(s):  
D. Josephine Selvarani Ruth

AbstractNickel Titanium Naval Ordinance Laboratory (NiTiNOL) is widely called as a shape memory alloy (SMA), a class of nonlinear smart material inherited with the functionally programmed property of varying electrical resistance during the transformation enabling to be positioned as a sensing element. The major challenge to instrument the SMA wires is to suppress the wires’ nonlinearity by proper selection of two important factors. The first factor is influenced by the mechanical biasing element and the other is to identify the sensing current for the sensing device (SMA wires + biasing). This paper focuses on developing SMA wires for sensing in different orientation types and configurations by removing the non-linearity in the system’s output by introducing inverse hysteresis to the wires through the passive mechanical element.


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