Seismic Control and Performance of Passive Hybrid Damper Under Near-Field Earthquakes

2020 ◽  
pp. 1-13 ◽  
Author(s):  
Swabarna Roy ◽  
Swagato Das ◽  
Purnachandra Saha
Keyword(s):  
Near Field ◽  
Seismic Control ◽  
And Performance ◽  
Hybrid Damper

Some Important Mechanisms and Processes in the Near Field of the Swedish Repository for Spent Nuclear Fuel

1992 ◽  
Vol 294 ◽  
Author(s):  
Ivars Neretnieks
Keyword(s):  
Molecular Diffusion ◽  
Spent Nuclear Fuel ◽  
Dominant Role ◽  
Near Field ◽  
Water Flow Rate ◽  
Crystalline Rock ◽  
Diffusive Transport ◽  
Actual Design ◽  
Natural Analogues ◽  
And Performance

ABSTRACTIn repositories for nuclear waste there are many processes that will be instrumental in damaging the canisters and releasing the nuclides. Based on experiences from studies of the performance of repositories and of an actual design, the major mechanisms influencing the integrity and performance of a repository are described and discussed. The paper addresses only conditions in crystalline rock repositories. The low water flow rate in fractures and channels plays a dominant role in limiting the interaction between water and waste. Molecular diffusion in the backfill and rock matrix, as well as in the mobile water, is an important transport process, but actually limits the exchange rate because diffusive transport is slow. Solubility limits of both waste matrix and of individual nuclides are also important. Complicating processes include alpha-radiolysis, which may change the water chemistry in the near-field. The sizes and locations of water flowpaths and damages in the canisters considerably influence the release rates. Uncertainties in data are large. Nevertheless the system is very robust in the sense that practically no reasonably conceivable assumptions or data will lead to large nuclide releases. Several natural analogues have been found to exhibit similarities with a waste repository and help to validate concepts and to increase our confidence that all major issues have been considered.

scholarly journals IDA-Pay: a secure and efficient micro-payment system based on Peer-to-Peer NFC technology for Android mobile devices

2012 ◽  
Vol 8 (4) ◽  
pp. 117 ◽  
Author(s):  
Luca Mainetti ◽  
Luigi Patrono ◽  
Roberto Vergallo
Keyword(s):  
Mobile Devices ◽  
Near Field ◽  
Operating Mode ◽  
Peer To Peer ◽  
Payment System ◽  
Third Party ◽  
Payment Systems ◽  
Shopping Experience ◽  
And Performance ◽  
System Effectiveness

The evolution of modern mobile devices towards novel Radio Frequency (RF) capabilities, such as Near Field Communication, leads to a potential for delivering innovative mobile services, which is still partially unexplored. Mobile proximity payment systems are going to enhance the daily shopping experience, but the access to payment security resources of a mobile device (e.g. the “Secure Element”) by third party applications is still blocked by smartphone and Operating System manufacturers. In this paper, the IDA-Pay system is presented, an innovative and secure NFC micro-payment system based on Peer-to-Peer NFC operating mode for Android mobile phones. It allows to deliver mobile-to-POS micro-payment services, bypassing the need for special hardware. A validation scenario and a system evaluation are also reported to demonstrate the system effectiveness and performance.

Shake Table Studies on Viscous Dampers in Seismic Control of a Single-Tower Cable-Stayed Bridge Model under Near-Field Ground Motions

2018 ◽  
Vol 12 (05) ◽  
pp. 1850011 ◽  
Author(s):  
Jiang Yi ◽  
Jianzhong Li ◽  
Zhongguo Guan
Keyword(s):  
Ground Motions ◽  
Near Field ◽  
Far Field ◽  
Viscous Damper ◽  
Viscous Dampers ◽  
Damping Force ◽  
Seismic Control ◽  
Cable Stayed Bridge ◽  
Bridge Model ◽  
Cable Stayed Bridges

To investigate the effectiveness of viscous damper on seismic control of single-tower cable-stayed bridges subjected to near-field ground motions, a 1/20-scale full cable-stayed bridge model was designed, constructed and tested on shake tables. A typical far-field ground motion and a near-field one were used to excite the bridge model from low to high intensity. The seismic responses of the bridge model with and without viscous dampers were analyzed and compared. Both numerical and test results revealed that viscous dampers are quite effective in controlling deck displacement of cable-stayed bridges subjected to near-field ground motions. However, due to near-field effects, viscous damper dissipated most energy through one large hysteresis loop, extensively increasing the deformation and damping force demand of the damper. Further study based on numerical analysis reveals that to optimize deck displacement of cable-stayed bridges during an earthquake, a viscous damper with relatively larger damping coefficient should be introduced under near-field ground motions than far-field ones.

Nanometer Material Processing Using NSOM-delivered Femtosecond Laser Pulses

2004 ◽  
Vol 850 ◽  
Author(s):  
Chen-Hsiung Cheng ◽  
Ming Li
Keyword(s):  
Substrate Surface ◽  
Near Field ◽  
Laser Pulses ◽  
Optical Microscope ◽  
Femtosecond Laser Pulses ◽  
Surface Topology ◽  
Field Range ◽  
Field Coupling ◽  
Nanometer Material ◽  
And Performance

ABSTRACTNanometer-scale surface topology modification has been demonstrated using NSOM (near-field scanning optical microscope) delivered femto-second pulses. The ablation laser has a pulse width of 150 femto-second and wavelength of 387-nm. The laser pulses are coupled into the free end of a multimode optical fiber that a nanometer-size NSOM probe was fabricated on the other end with small orifice. The transmitted laser pulses from the probe orifice illuminates and machines the substrate surface when the probe is in near-field range of the substrate surface. The produced feature on Silicon surface is as least 200-nm deep with hole diameter around 200-nm. Near-field coupling of the laser has the potential to achieve ablation of feature size less than diffraction limit. Using NSOM delivery method also allows us to take advantage of nanometer metrology in precision surface ablation or other type of preformed surface modification. The ability of monitoring surface topology of substrate in real time enables us to accomplish the in-situ surface processing. We have demonstrated the technique of drilling 200-nm air holes on a pre-formed 600-nm wide wave guide. This method can be used to fabricate one-dimensional photonic crystal on a waveguide in ambient environment. The experiment design and performance evaluation will be discussed.

Commissioning of an Atypical Acoustic Facility for Experimental Testing

2016 ◽  
Vol 59 (1) ◽  
pp. 22-39 ◽  
Author(s):  
Viken N. Koukounian ◽  
Chris K. Mechefske
Keyword(s):  
Sound Pressure ◽  
Experimental Testing ◽  
Signal To Noise Ratio ◽  
Near Field ◽  
Sound Pressure Levels ◽  
Compliance Measure ◽  
And Performance ◽  
Reverberant Field ◽  
International Testing ◽  
Testing Standards

Abstract Computational modeling (BEM, FEM, and SEA) is often implemented at different stages of the design process to optimize manufacturing and performance parameters. Computational results are typically verified experimentally. Experimental testing standards, particularly those related to vibro-acoustic testing, are defined by various agencies such as ASTM, ANSI, and ISO. An investigation proposing a new computational methodology of analyzing the vibro-acoustic behavior of an aircraft fuselage due to the turbulent boundary layer required verification of the predictions experimentally. In the face of certain limitations, an atypical acoustic facility was constructed challenging conventional standards while complying with the defined criteria of international testing standards. Principal deviations relate to the geometric requirements that recommend large volumes of certain construct, and microphone and acoustic source positioning. The calculated 95% confidence intervals compared exceptionally well against defined criteria (strictest measure is 1 for frequencies greater than 315 Hz) by averaging less than 0.4 for each test product across a frequency range that exceeded is the range specified by ASTM E90. The requirements for qualification of the reverberation chamber according to ANSI S12.51 were also satisfied, with the exception of measurements at 125 Hz and 160 Hz that observed heightened sensitivity due to near field effects and room modes. The calculated permissible ratio of decay variation showed good agreement against ASTM C423 criteria despite the intrinsic challenge of creating a diffuse and reverberant field in a confined, or constricting, volume. The last compliance measure reviewed flanking to ensure acceptable signal-to-noise ratio. It was clearly demonstrated that the silenced sound pressure levels (with the presence of the specimen) were greater than 10 dB above the background sound pressure levels (with the consequences of flanking considered). The investigation confirmed the feasibility of using an atypical acoustic facility to comply with various international testing standards. The noted deviations and shortcomings are not specific to the presented work, but are common challenges that all facilities observe.

Effective Design and Performance of an Optical Flying Head for Near-Field Recording

2002 ◽  
Vol 41 (Part 1, No. 3B) ◽  
pp. 1884-1888 ◽  
Author(s):  
Sookyung Kim ◽  
Youngsik Kim ◽  
Jin-Moo Park ◽  
Jin-Yong Kim ◽  
Jin-Hong Kim
Keyword(s):  
Near Field ◽  
Field Recording ◽  
And Performance ◽  
Effective Design

Embedded nano-optic media for near-field high-density optical data storage: modeling, fabrication, and performance

2002 ◽  
Author(s):  
John M. Guerra ◽  
Dmitri Vezenov ◽  
Luke Thulin ◽  
W. Haimberger ◽  
Paul F. Sullivan ◽  
...  
Keyword(s):  
Data Storage ◽  
Near Field ◽  
Optical Data Storage ◽  
High Density ◽  
Optical Data ◽  
And Performance

scholarly journals Mitigation of Earthquake Responses Using SMA Supplemented Base-Isolation Devices for Benchmark Building

2021 ◽  
Vol 2 (4) ◽  
pp. 22-30
Author(s):  
Ashish R. Akhare
Keyword(s):  
Degrees Of Freedom ◽  
Base Isolation ◽  
Near Field ◽  
Evaluation Criteria ◽  
Time History ◽  
Base Shear ◽  
Comparative Performance ◽  
Isolation System ◽  
Seismic Control ◽  
Isolation Systems

The efficiency of traditional isolation bearings is doubted for near-field earthquakes because these bearings undergo large displacement. A comparative study of different base isolation systems of base-isolated benchmark building is carried out in the present study. The study is based on assumption that buildings are bi-directionally acted upon by near-field earthquakes for assessing their relative performance in seismic control of the benchmark building. The time history variations of important response parameters and evaluation criteria of the benchmark building has been studied for assessing the effectiveness of the isolation systems. The Shape Memory Alloy (SMA) is utilized with elastomeric bearings and friction bearings to study the effectiveness of SMA wires with different isolators. The benchmark building is modelled as a discrete linear elastic shear structure having three degrees of- freedom at each floor level. Time domain dynamic analysis of this building has been carried out with the help of constant average acceleration Newmark’s method and equilibrium of non-linear forces has been taken care by fourth order Runge-Kutta method. The comparative performance of various isolation systems has been studied with uniform and hybrid combinations. The hybrid combination of SMA supplemented bearings works out the better isolation system keeping in view of the percentage reduction in evaluation criteria for smart base-isolated benchmark building. Furthermore, it is shown that, the functionality of SMA wire is not efficient with Lead Rubber Bearing system, as it is able to control displacement but increases the acceleration, base shear, story drift and isolation forces.

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