Passive control technologies for seismic-resistant buildings in Europe

2001 ◽  
Vol 3 (3) ◽  
pp. 277-287 ◽  
Author(s):  
Federico M Mazzolani
Keyword(s):  
Passive Control ◽  
Seismic Resistant ◽  
Control Technologies

scholarly journals A Review of the Evaluation, Control, and Application Technologies for Drill String Vibrations and Shocks in Oil and Gas Well

2016 ◽  
Vol 2016 ◽  
pp. 1-34 ◽  
Author(s):  
Guangjian Dong ◽  
Ping Chen
Keyword(s):  
Passive Control ◽  
Oil And Gas ◽  
Field Studies ◽  
Drill String ◽  
Vibration Measurement ◽  
Semiactive Control ◽  
Rate Of Penetration ◽  
Drilling Performance ◽  
String Vibrations ◽  
Control Technologies

Drill string vibrations and shocks (V&S) can limit the optimization of drilling performance, which is a key problem for trajectory optimizing, wellbore design, increasing drill tools life, rate of penetration, and intelligent drilling. The directional wells and other special trajectory drilling technologies are often used in deep water, deep well, hard rock, and brittle shale formations. In drilling these complex wells, the cost caused by V&S increases. According to past theories, indoor experiments, and field studies, the relations among ten kinds of V&S, which contain basic forms, response frequency, and amplitude, are summarized and discussed. Two evaluation methods are compared systematically, such as theoretical and measurement methods. Typical vibration measurement tools are investigated and discussed. The control technologies for drill string V&S are divided into passive control, active control, and semiactive control. Key methods for and critical equipment of three control types are compared. Based on the past development, a controlling program of drill string V&S is devised. Application technologies of the drill string V&S are discussed, such as improving the rate of penetration, controlling borehole trajectory, finding source of seismic while drilling, and reducing the friction of drill string. Related discussions and recommendations for evaluating, controlling, and applying the drill string V&S are made.

scholarly journals A Critical Review of Stall Control Techniques in Industrial Fans

2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Stefano Bianchi ◽  
Alessandro Corsini ◽  
Anthony G. Sheard ◽  
Cecilia Tortora
Keyword(s):  
Control Systems ◽  
Passive Control ◽  
Control Strategies ◽  
Warning System ◽  
Detection Methods ◽  
Stall Inception ◽  
Stall Margin ◽  
Control Techniques ◽  
Control Technologies ◽  
And Control

This paper reviews modelling and interpretation advances of industrial fan stall phenomena, related stall detection methods, and control technologies. Competing theories have helped engineers refine fan stability and control technology. With the development of these theories, three major issues have emerged. In this paper, we first consider the interplay between aerodynamic perturbations and instability inception. An understanding of the key physical phenomena that occurs with stall inception is critical to alleviate stall by design or through active or passive control methods. We then review the use of passive and active control strategies to improve fan stability. Whilst historically compressor design engineers have used passive control techniques, recent technologies have prompted them to install high-response stall detection and control systems that provide industrial fan designers with new insight into how they may detect and control stall. Finally, the paper reviews the methods and prospects for early stall detection to complement control systems with a warning capability. Engineers may use an effective real-time stall warning system to extend a fan’s operating range by allowing it to operate safely at a reduced stall margin. This may also enable the fan to operate in service at a more efficient point on its characteristic.

Experimental Study for a New Energy Dissipation Device: Multiple-Direction Damper

2002 ◽  
Author(s):  
C. S. Tsai ◽  
L. L. Chung ◽  
T. C. Chiang ◽  
B. J. Chen ◽  
W. S. Chen
Keyword(s):  
Energy Dissipation ◽  
Passive Control ◽  
Steel Structure ◽  
Experimental Results ◽  
Shaking Table ◽  
New Energy ◽  
Seismic Loadings ◽  
Control Technologies ◽  
Energy Dissipation Devices ◽  
Energy Absorbing

The way of passive control technologies has been recognized as an excellent method to mitigate seismic responses of structures during seismic excitations. In general, the energy dissipation devices based on their own mechanical property can be divided into two categories, which are velocity-dependent and displacement-dependent devices. In this study, a new displacement-dependent device which is called multiple-direction damper is proposed. The proposed damper has numerous advantages: (1) the fabrication of this energy-absorbing device is effortless; (2) the construction of the energy-absorbing system is easy; (3) it is simple to install the device into a structure; (4) the material used for this damper is easy to obtain; and (5) if any damage occurs in this damper during strong excitations, this energy-absorbing device can be replaced easily to recover its energy dissipation capacity. Experimental results from component tests show that the proposed damper provides significant energy-absorbing capacity. Furthermore, the multiple-direction dampers have also been equipped into a 5-story steel structure to demonstrate its efficiency on seismic mitigation. The experimental results from shaking table tests indicate that most of earthquake-induced energy imparted into the structure is dissipated by the proposed dampers. In the meanwhile, the seismic loadings imposing on the structure with devices can be reduced effectively as compared with those of the bare structure. Therefore, the multiple-direction damper can be recognized as an effective tool to assure the safety of structure under strong ground motions.

Passive Control of a Hydraulic Valve

1989 ◽  
Author(s):  
John D. Charlton ◽  
James J. Brickley
Keyword(s):  
Passive Control ◽  
Hydraulic Valve
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