Free-field response

A number of corrections must be applied in order to obtain accurate data. The sound pressure level (SPL) at each frequency needs to be determined through the use of the raw data. The corrections for the actuator response as well as the free-field response are then applied at each frequency. Lastly, the effect of atmospheric absorption at each frequency needs to be determined and applied. This was done through the use of formulas provided by Blackstock [14]. The corrected SPL values are then converted back into pressure values and integration... 

Effect of PGA on Free-Field Response and Kinematic Bending Moments... 

Study of the soil pressure transfer functions and the free-field response motions for wall with height of 50 ft showed that spectral values at the soil column frequency and at 30 % damping have the best correlation with the forces computed directly from the SSI analysis (Ostadan (2004)). 

Obtain the total seismic lateral force by multiplying the mass of the representative SDOF by the spectral amplitude of the free-field response at the soil colunm frequency. 

Determine the seismic wave transmission characteristics of the site and define a free-field response spectral shape consistent with these characteristics. 

The 1 percent damping Housner free field response spectrum anchored at 0.2g and amplified by 10 percent shall be used as the FRS for piping systems that have a dynamic analyses of record. 

For any new dynamic analyses of piping systems, the FRS developed from R.G. 1.60 free-field response spectra shall be used. If other FRS are used, they shall be justified. 

The 1 percent damping Housner free field response spectrum anchored at 0 2g and amplified by 10 percent shall be used as the FRS only for equipment on which a dynamic analysis of record has already been performed. Use the FRS developed, for the restart program (RP) (URS/JAB 6193, 06, "Floor Acceleration Response Spectra for Updated DBF and Reg. Guide 1.60 Seismic Input, Building 105K, Savannah River Plant," August 1989) for new analyses conducted after February 1989. Justify other FRS used. 

Use the free field response spectrum to compare with the bounding spectrum, if the equipment is at least 8 cps. Use the FRS to compare with the bounding spectrum times 1.5, if the equipment is less than 8 cps. 

The surface potential of a liquid solvent s, %, is defined as the difference in electrical potentials across the interface between this solvent and the gas phase, with the assumption that the outer potential of the solvent is zero. The potential arises from a preferred orientation of the solvent dipoles in the free surface zone. At the surface of the solution, the electric field responsible for the surface potential may arise from a preferred orientation of the solvent and solute dipoles, and from the ionic double layer. The potential as the difference in electrical potential across the interface between the phase and gas, is not measurable. However, the relative changes caused by the change in the solution s composition can be determined using the proper voltaic cells (see Sections XII-XV). 

Dickson and Becke, 1996, use a basis set free numerical approach for obtaining their LDA dipole moments, which defines the complete basis set limit. In all other investigations basis sets of at least polarized triple-zeta quality were employed. Some of these basis sets have been designed explicitly for electric field response properties, albeit in the wave function domain. In this category belong the POL basis sets designed by Sadlej and used by many authors as well as basis sets augmented by field-induced polarization (FTP) func-... 

A practical consequence of architecture is to permit acoustical performances to large numbers of listeners by enclosing the sound source within walls. This dramatically increases the sound energy to listeners, particularly those far from the source, relative to free field conditions. A measure of the resulting frequency dependent gain of the room can be obtained from the EDR evaluated at time 0. This frequency response can be considered to be an equalization applied by the room, and is often easily perceived. 

Currently, to develop more highly functionalized LC devices, intensive studies are being carried out on electrically controllable polymer/LC composite films with such advantageous features as high electric field response, high contrast, and wide viewing angle, as well as reverse-mode and haze-free characteristics. 96-100 ... 

In a thin film, a vertical electric field such as that applied in a parallel-plate capacitor geometry drives a standing alignment of L or Cl microdomains. There is, therefore, a competition between the electric field and the surface fields that favor parallel domain alignment (L or C ). The free energy of Eq. 2.7 is modified in a simple model to include distinct contributions from the surface interactions and the electric field response ... 

This type of input acceleration was imposed by sinusoidal excitation consisting of 15 steady cycles. To smoothen out the transition between transient and steady-state response, the excitation comprises of a 5-cycle ramp up to full test level at the beginning of the excitation, and a 5-cycle ramp down to zero at the end. With reference to frequency and acceleration level, a set of five frequencies (4, 7,13, 25 and 43 Hz) was used at low acceleration amplitude of 0.05g, to study the dynamic response of the system. The excitation frequency of 7 Hz was then selected for a series of harmonic excitations with increasing amplitude, until failure. The conditions of the excitation are considered to be essentially pseudostatic, as the above frequency is much smaller than the resonant frequencies of the system, with respect to both the free field and the soil-wall system. 

Regardless of the exposure to seismic hazard, an SI 2 design basis earthquakes should be adopted for every nuclear power plant for the design of safety classified items. The minimum level should correspond to a peak ground acceleration of O.lg (zero period of the design response spectrum), to be considered at the free field. A unified, site compatible spectrum should be associated with this peak ground acceleration value. In this case SL-1 may be assumed to be coincident with SL-2. 

Rizos, D.C. Sc Loya, K.G. 2002. Dynamic and seismic analysis of foundations based on free field B-Spline characteristic response histories. Journal of Engineering Mechanics 128 438—448. 

The SSIeffectontheMTMD control effectiveness has been evaluated by Lin etal. (2005) with the employment of a methodology developed by Wuetal. (2001).With and without TMD/MTMD, the mean-square-response ratio of floortranslation wilii respect to free-field ground acceleration,, versus [Pg.142]

Figure 10. Mean-square-response ratio of floor displacement with respect to free-field ground acceleration versus a with and without TMD/MTMD in the cases of 3 and A = 5...

The second part of ISO 17497 specifies a method of measuring the directional diffusion coefficient of surfaces in a free field (ISO, 17497-2, 2012). The diffusion coefficient characterizes the sound reflected from a surface in terms of the uniformity of the reflected polar distribution. The directional diffusion coefficient is a frequency dependent value derived from the polar distribution of the scattered sound (Cox and D Antonio, 2009). First the scattering from a surface is measured in terms of a polar distribution. Then the diffusion coefficient is evaluated at 1/3 octave bandwidth intervals, which has the advantage of smoothing out some of the local variations in the polar responses. 

Solute(s) and solvent are defined by means of force-fields, and the average representation of the solvated system is obtained by means of Molecular Dynamics (MD) or Monte Carlo (MC) techniques, which provide Boltzmann-averaged samplings of the system. This information can be subsequently utilized to determine absolute and relatives free energies of solvation. This can be accomplished by using a) linear free energy response (LFER) theory and b) statistical mechanical (SM) methods. 

Seismic hazard calculation to obtain the seismic hazard curves (at free field conditions). Two seismic levels SL-1 and SL-2 should be defined by the Regulator (usually 475 and 10,000 year return periods). They are characterized by response spectra and appropriate time histories. 

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