Two-timescale evolution of extreme-mass-ratio inspirals: Waveform generation scheme for quasicircular orbits in Schwarzschild spacetime

Tuned mass dampers (TMD) are one of the most reliable devices to control the vibration of the structure. The optimum mass ratio required for a single tuned mass damper (STMD) is evaluated corresponding to the fundamental natural frequency of the structure. The effect of STMD and Multiple tuned mass dampers (MTMD) on a G+20 storey structure are studied to demonstrate the damper’s effectiveness in seismic application. The location and number of tuned mass dampers are studied to give best structural performance in maximum reduction of seismic response for El Centro earthquake data. The analysis results from SAP 2000 software tool shows damper weighing 2.5% of the total weight of the structure effectively reduce the response of the structure. Study shows that introduction of 4-MTMD at top storey can effectively reduce the response by 10% more in comparison to single tuned mass damper. The use of MTMD of same mass ratio that of STMD is more effective in seismic response.

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Chitosan-based Magnetic Composites - Efficient Adsorbents for Removal of Pb(II) and Cu(II) from Aqueous Mono and Bicomponent Solutions

Revista de Chimie ◽

10.37358/rc.18.9.6527 ◽

2018 ◽

Vol 69 (9) ◽

pp. 2323-2330 ◽

Cited By ~ 1

Author(s):

Daniela C. Culita ◽

Claudia Maria Simonescu ◽

Rodica Elena Patescu ◽

Nicolae Stanica

Keyword(s):

Aqueous Solutions ◽

Metal Ions ◽

Chemical Properties ◽

Order Kinetic ◽

Mass Ratio ◽

Magnetic Adsorbent ◽

Magnetic Composites ◽

Initial Ph ◽

Order Kinetic Model ◽

Physical And Chemical

A series of three chitosan-based magnetic composites was prepared through a simple coprecipitation method. It was investigated the influence of mass ratio between chitosan and magnetite on the physical and chemical properties of the composites in order to establish the optimum conditions for obtaining a composite with good adsorption capacity for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions. It was found that the microspheres prepared using mass ratio chitosan / magnetite 1.25/1, having a saturation magnetization of 15 emu g--1, are the best to be used as adsorbent for the metal ions. The influence of different parameters such as initial pH values, contact time, initial concentration of metal ions, on the adsorption of Pb(II) and Cu(II) onto the chitosan-based magnetic adsorbent was investigated in details. The adsorption process fits the pseudo-second-order kinetic model in both mono and bicomponent systems, and the maximum adsorption capacities calculated on the basis of the Langmuir model were 79.4 mg g--1 for Pb(II) and 48.5 mg g--1 for Cu(II) in monocomponent systems, while in bicomponent systems were 88.3 and 49.5 mg g--1, respectively. The results revealed that the as prepared chitosan-based magnetic adsorbent can be an effective and promising adsorbent for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions.

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Applications of Optical Coherent Transient Technology to Pulse Shaping, Spectral Filtering, Arbitrary Waveform Generation and RF Beamforming

10.21236/ada452139 ◽

2006 ◽

Author(s):

W. R. Babbitt ◽

Mingzhen Tian ◽

Kelvin Wagner

Keyword(s):

Pulse Shaping ◽

Spectral Filtering ◽

Arbitrary Waveform Generation ◽

Waveform Generation ◽

Arbitrary Waveform ◽

Optical Coherent Transient

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ACCURACY RATING MEASUREMENT OF VIBRATION ELECTROMECHANICAL DEVICES

Issues of radio electronics ◽

10.21778/2218-5453-2019-7-42-45 ◽

2019 ◽

Vol 1 (7) ◽

pp. 42-45

Author(s):

V. A. Golubkov ◽

V. F. Shishlakov ◽

A. G. Fedorenko ◽

E. Yu. Vataeva

Keyword(s):

Technical Condition ◽

Rotor System ◽

Vibration Measurement ◽

Random Errors ◽

Mass Ratio ◽

Signal Flow Graph ◽

Bond Graphs ◽

Rotor Systems ◽

Electromechanical Devices ◽

Main Components

Electromechanical devices consist mainly of rotor systems. Vibration is the result of the interaction of the elements of the rotor system and is largely determined by the accuracy of manufacturing elements at the production stage and defects arising in the process of operation. The main components of the rotor systems that affect vibration are bearings. To determine the technical condition of the bearings and the service life of the rotor system, it is necessary to accurately measure the unobservable vibrations of the rotor. The article describes the model of the channel for measuring the vibration of an electromechanical system, built using the apparatus of bond graphs. The transfer function is obtained by analyzing the signal flow graph. The systematic and random errors of vibration measurement are analyzed depending on the mass ratio between the system case and the vibration transducer for various sensor masses and attachment rigidity.

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