Ground vibrations during an earthquake can severely damage structures and equipments housed in them. Many factors including earthquake magnitude, distance from the fault or epicenter, duration of strong shaking, soil condition of the site, and the frequency content of the motion define the properties of ground motion and its amplification. A deep understanding of the effects of these factors on the response of structures and equipmentsessential for a safe and economical DESIGN. Some of these effects such as the amplitude of the motion, frequency content, and local soil conditions are best represented through a response spectrum, which describes the maximum response of a damped single-degreeof-freedom (SDOF) oscillator with various frequencies or periods to ground motion.Earthquake ground motion is usually measured by strong motion instruments, which record the acceleration of the ground. The recorded accelerograms, after corrections for instrument errors and baseline, are integrated to obtain the velocity and displacement time-histories.The maximum response of a SDOF system excited at its base by a time acceleration function is expressed in terms of only three parameters: (1) the natural frequency of the system, (2) the amount of damping, and (3) the acceleration time-history of the ground motion. Response spectrum analysis is the dominant contemporary method for dynamic analysis of building structures under seismic loading. The main reasons for the widespread use of this method are: its relative simplicity, its inherent conservatism, and its applicability to elastic analysis of complex systems. Since the detailed characteristics of future earthquakes are not known, the majority of earthquake DESIGN SPECTRA are obtained by weighted averaging of a set of response SPECTRA from records with similar characteristics such as soil condition, epicentral distance, magnitude and source mechanism.The DESIGN spectrum specifies the DESIGN seismic acceleration, velocity or displacement at a given frequency or period if it is derived from ground acceleration, velocity or displacement time histories. For practical applications, DESIGN SPECTRA are presented as smooth curves or straight lines. Smoothing is carried out to eliminate the peaks and valleys in the response SPECTRA that are not desirable for DESIGN because of the difficulties encountered in determining the exact frequencies and mode shapes of structures during severe earthquakes when the structural behavior is most likely nonlinear. Since the peak ground acceleration, velocity, and displacement for various earthquake records are different, the computed response cannot be averaged on an absolute basis. Thus, normalization is needed to make a standard basis for averaging.Various procedures are used to normalize the response SPECTRA before averaging is carried out. Among these procedures, one has been the most commonly used, which is normalization with respect to peak ground motion to make the same peak ground motion for all ground motion time histories.Building codes commonly present DESIGN SPECTRA in terms of acceleration amplification as a function of period on an arithmetic scale. In this study, the data from Accelerographic network stations are deployed on rock sites of Iran with shear wave velocity larger than 750 m/s, which is equivalent to site Type I in the Iranian seismic building code. The Seismosignal software is used to do both baseline correction and filtering for all the dominant horizontal and vertical components to reduce the inherent error of the motion. Among all the ground motions, only 103 vertical and 109 dominant horizontal time histories are accepted after baseline correction and filtering. The data are classified considering different combinations of the range of magnitude and distance. The epicentral distance is classified as near field (0-35 km), medium distance (35-65 km) and far field (65-100 km), while the earthquake magnitude is classified as small earthquake (4.5<M<5.5), medium earthquake (5.5<M<6.5) and large earthquake (6.5<M<7.5), after which the vertical and the horizontal response SPECTRA are prepared for each time history for %5 damping ratio. Obviously, the result can be generalized to other damping ratios.By averaging the response SPECTRA is obtained an unsmoothed DESIGN SPECTRA. A smoothed DESIGN SPECTRA is plotted by averaging of acceleration amplification SPECTRA for each frequency. This procedure is repeated for an average plus one standard deviation of bothvertical and horizontal response SPECTRA.Eventually, the smoothed DESIGN SPECTRA determined in this study are compared with that of the regional attenuation relationships obtained based on the data from Europe and the Middle East (Ambraseys et al., 2005). The comparisons show relatively good correlation between the spectrum obtained in this study and the regional attenuation relationships for periods greater than about 0.19s and weak correlation for periods of less than it.

This paper discusses the estimation of wind dynamic response of two types of structures by following classical and novel approaches. A new method for structural analysis based on wind DESIGN SPECTRA is introduced and tested against simulated and experimental data. DESIGN SPECTRA are derived from the dynamic response of a group of oscillators subject to wind, using similar techniques than those used to derive DESIGN SPECTRA for seismic engineering applications. The method is used on three chimneys of different height as well as on a regular building which has been experimentally tested in the past. The chimneys and building are also submitted to simulated wind fields to provide additional sets of results. It is observed that the SPECTRAl approach is consistent with experimental and simulated results and therefore is concluded that DESIGN SPECTRA can cover broad range of practical applications.

DESIGN spectrums are used to compute seismic demand in structural DESIGN process. Therefore, seismic DESIGNcodes try to provide safety margin in performance of structures by developing appropriate DESIGN SPECTRA. TheDESIGN SPECTRA in Iranian seismic DESIGN code (Standard No. 2800) were developed via the analysis of differentearthquake response SPECTRA. In Standard 2800, a mapped PGA value for 10% in 50 years used as an anchor point toproduce the DESIGN spectrum at a desired point. Meanwhile, this approach fails to provide a quantitative safetymargin as claimed in DESIGN code. Furthermore, their accuracy have not yet been examined by conventionalapproach such as uniform hazard SPECTRA (UHS), which is conventionally employed by many DESIGN codes such asEurocode 8 (1998). SPECTRAl ordinates of UHS have equal probability of exceedance (PE) across all periods ofvibration. Therefore, DESIGNed structures with recent DESIGN spectrums have the same imposed seismic hazard level.An attempt was made in this study to directly examine the accuracy of proposed DESIGN SPECTRA in Standard 2800by those of UHS derived in Tehran Megacity as a case study. For this purpose, the area under study is divided into632 grids with a 1 km × 1 km area. The hazard curve was calculated by considering the soil type at each grid pointas defined in Standard 2800 from hard to soft (I to IV). The number of grids fall at each soil type are 10, 465, 150and 7 points for I, II, III and IV soil types, respectively. Hazard curves at the grid points were calculated and wereused to compute uniform hazard SPECTRA for 2% and 10% PE in 50 years (return periods of 2475 and 475 years,respectively). For each soil type, the mean of uniform hazard SPECTRA at different grid points with the same soil typewere calculated, which were used as a representative uniform hazard spectrum for that soil type. The derivedrepresentative uniform hazard SPECTRA for 10% PE in 50 years were compared with those proposed in Standard 2800for different soil types. Furthermore, SPECTRAl acceleration ratio of uniform hazard with respect to those fromStandard 2800 at periods of 0.2 s and 1.0 s were computed and were compared for the whole points according totheir soil types. The outcomes reveal that the SPECTRAl acceleration in DESIGN SPECTRA of Standard 2800 are larger thanthose in UHS for all the periods, especially for the periods larger than 0.5 s for soil types I and II. Meanwhile, theSPECTRAl accelerations of Standard 2800 become almost the same at periods lower than 0.5 s, and again becomelarger than UHS at periods larger than 0.5 s for soil types III and IV. In general, it is found that the proposed DESIGNSPECTRA in Standard 2800 are conservative. This may need further examine by more recent approach such as uniformrisk, and then being considered in future revision of Standard 2800.

DESIGN spectrum is known as an essential tool in earthquake engineering for calculation of maximum (DESIGN) responses in a structural system. Soil-structure interaction (SSI), as a phenomenon of coupling of responses of a structure and its underlying soil, was explored after introduction of DESIGN SPECTRA and has not been taken into account in developing a DESIGN spectrum traditionally. To consider the SSI automatically when doing a spectrum analysis, in this paper maximum response of a single degree of freedom system resting on a flexible base is determined under consistent earthquakes. Consistency of earthquakes is maintained by considering their magnitude, distance, local soil type, and return period. The latter parameter is accounted by the use of earthquake categories identified by their similar SPECTRAl values at short periods. Different types of soils and two categories of earthquakes regarding their distance, being near field and far field, are considered. The results are presented as smoothed DESIGN SPECTRA. It is shown that SSI alters the response acceleration of buildings having up to about 10 stories and is ineffective for the rest. It has an increasing effect for the response acceleration of buildings up to about 5 stories.

Preparation of site-specific SPECTRA for alluvium and DESIGN of tall and special structures are needed. Due to placement of the city of Ardabil on the alluvium and developing of construction in the central part of the city, preparing of site-specific DESIGN SPECTRA is inevitable and worthwhile. In this paper, according to the geotechnical boreholes and tests to a depth of 40 meters in different parts of the city, beside probabilistic risk analysis, site- specific SPECTRA for central part of the city are developed. Based on the distribution of boreholes, the area is divided into 15 districts, with an area of one square kilometer. Through the probabilistic risk analysis, DESIGN acceleration of 0.32g is obtained for earthquakes with a return period of 475 years, which is 6% higher than that proposed by Building DESIGN Codes for Earthquakes- Standard 2800.DESIGN SPECTRA are obtained using three methods of ground response analysis, statistical analysis of different earthquakes and uniform hazard SPECTRA. Using the data from geotechnical measurements, soil types in the different areas of the city center is DESIGNated. The soil types in the most parts of studied area are classified as type III of the standard 2800 classification. Comparison of the obtained spectrum with the proposed spectrum of standard 2800, showed that in the range of constant acceleration, the values of site-specific DESIGN SPECTRA is 25% higher than those proposed by the standard 2800.

Uniform hazard spectrum is a modern and effective method in achieving the DESIGN SPECTRA that provide a uniform desirable safety level in performance of structures with different periods. In this study uniform hazard spectrum is determined for Tehran region considering the area and line seismic sources in the DESIGN area using the probabilistic analysis of seismic hazard and SPECTRAl attenuation relations. As the ground motions in nearby fault regions cause large damage, in this research the effects of site closeness to the seismic sources is taken into account considering near source SPECTRAl attenuation relations besides the far field attenuation ones.The results gained by this method are presented in the form of uniform hazard spectrum, peak ground acceleration and SPECTRAl acceleration maps in different periods. Uniform hazard spectrum is obtained by applying approximate method using average values of SPECTRAl acceleration in two or three controlling periods and it is compared to the SPECTRA suggested by UBC97 and Iranian 2800-84 codes.

Understanding how regional geology and soil conditions affect the intensity of ground shaking is one of the fundamental tasks of seismology and earthquake engineering. As a result, it is necessary to explore a wide range of features, including material, nonlinearity, and different non-linear models. In this study, five different earthquake models with peak accelerations ranging from 0.01 to 0.8g are used to examine the impact of the local site on DESIGN parameters. This study uses three different types of recorded ground motions, with maximum accelerations between 0.001 and 0.1g (type I), 0.1 and 0.3g (type II), and 0.3 and 0.8g. (type III). Downhole tests in four bore-holes in the Hormozgan province were used to assess wave shear velocity (Vs) for this purpose. To determine soil parameters, various tests such as sieve or hydrometer and atterberg limits were performed on samples. The results showed that a larger frequency band is caused by increased soil cohesiveness and that the frequency band's increase enhances the possibility of resonance. Based on the results, it is clear that the non-linear method provides a more comprehensive explanation of true non-linearity in soil behavior than equivalent-linear approaches. This study tends to support the idea that site analysis is essential for significant projects and that response analysis should be performed on each identified site.

By application of DESIGN SPECTRA in seismic analyses, determination of DESIGN SPECTRA for different site conditions, magnitudes, safety levels and damping ratios will improve the accuracy of seismic analysis results. The result of this research provides different DESIGN acceleration SPECTRA based on Iran earthquakes database for different conditions. For this purpose first a set of 146 records was selected according to causative earthquake specifications, device error modification and site conditions. Then the DESIGN acceleration SPECTRA are determined for 4 different site conditions presented in Iranian code of practice for seismic resistant DESIGN of buildings (Standard No. 2800), different magnitudes (Ms£5.5 & Ms>5.5), different damping ratios (0, 2, 5, 10, 20 percent) and also various safety levels (50% & 84%). Also this research compares the determined DESIGN SPECTRA with those in Standard No. 2800.

Intracytoplasmic sperm injection (ICSI) is one of the most successful techniques of Assisted Reproductive Technology (ART) and is mostly in use for the treatment of infertility with male factors. In this method, before injecting sperm into the intracytoplasmic of the oocyte, cumulus cells around the oocyte must be stripped to facilitate the injection process. To achieve this, both enzymatic and mechanical methods are used in embryological laboratories for denudation, which has major deficiencies, including the possibility of damaging the oocyte prior to the injection process. In this research, a microfluidic-based device is introduced for the separation of cumulus cells around the oocyte with minimum manual operations. The results prove high efficiency, and non-destructive denudation of the oocyte with the reduced amount of culture medium leads to the low-cost preparation process of oocytes. The process can also be integrated with ICSI chips under development and will be reported shortly.