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111.
This paper describes the analysis of a parameter, “hydrodynamic demand,” which can be used to represent the potential for
tsunami drag force related damage to structures along coastlines. It is derived from the ratio of drag force to hydrostatic
force caused by a tsunami on the structure. It varies according to the instantaneous values of the current velocities and
flow depths during a tsunami inundation. To examine the effects of a tsunami in the present study, the analyses were performed
using the tsunami numerical model in two altered regular-shaped basins having different bottom slopes. The simulations were
implemented using a single sinusoidal wave with particular initial conditions, such as leading elevation wave and leading
depression wave profiles with different wave periods. Two different initial wave amplitudes were employed to assess the diversity
in the distribution of the square of the Froude number Fr
2 along the coastline. The numerical results were compared quantitatively. 相似文献
112.
The aim of this paper was to investigate a novel method of polyelectrolyte injection into deep bed filter media. The raw water and the filter media used in the pilot filters were obtained from the Omerli Reservoir that supplies one million m3/day of water to the greater city of Istanbul. A cationic polyelectrolyte was injected at the entrance of the filter and at different depths of the sand bed. The effect of polyelectrolyte injection location and method was evaluated by measuring the effluent turbidity, effluent particle count, and the head losses at different locations of the sand media. It was observed that the simultaneous injection of the polyelectrolyte on top of the filter bed and at the center can lengthen the filter run time while achieving an effluent turbidity as low as 0.06 NTU (nephelometric turbidity unit) and 4 log (99.99%) particle removal. 相似文献
113.
An effective medium approach is applied to elasto-plastic masonry to facilitate numerical modeling of the fourteen century old Hagia Sophia in Istanbul, Turkey. The analysis is treated in two distinct stages: quasi-static to account for the deformations incurred by the structure under gravitational loading during its construction phase, and dynamic to account for the response to numerous seismic excitations. Both historical and physical evidence suggest that the mortars employed throughout the Hagia Sophia were highly compliant on the construction time scale; recent chemical analysis of the mortars appears to confirm that they may not have had time to fully cure before the structure's construction was completed. The resulting highly compliant initial behavior of the masonries is modeled within an effective medium elasto-plasticity framework which is demonstrated here as capable of matching the existing magnitude and pattern of deformations in the structure. With the eventual curing of the mortar, the properties of the masonries throughout the structure became significantly stronger; this is taken into account in modeling the seismic response of the structure to a number of earthquake excitations. Specifically, a hardening elastoplastic behavior with increased strength is used to explore the initiation of partial failure mechanisms in the structure under strong seismic loading. 相似文献
114.
Turkey has been divided into eight different seismic regions taking into consideration the tectonic environments and epicenters
of the earthquakes to examine relationships of the modal values (a/b), the expected maximum magnitudes (Mmax) and the maximum intensities (Imax). For this purpose, the earthquakes for the time period 1900–1992 from the Global Hypocenter Data Base CD-ROM prepared by
USGS, and for the time period 1993–2001 from the PDE data and IRIS data are used. Concerning the relationships developed between
different magnitude scales and between surface wave magnitudes (MS) and intensity for different source regions in Turkey, we have constructed a uniform catalog of MS. We have estimated the values of Mmax and Imax using the Gumbel III asymptotic distribution. Highest a-values are observed in the Aegean region and the lowest b-values are estimated for the North Anatolian Fault. Maximum values of a/b, Mmax and Imax are related to the eastern and western part of the North Anatolian Fault and the Aegean Arc. The lowest values of all parameters
are observed near the Mid Anatolian Fault system. Linear relationships have been calculated between a/b, Mmax and Imax using orthogonal regression. If one of the three parameters is computed, two other parameters can be calculated empirically
using these linear relationships. Hazard maps of Mmax and Imax values are produced using these relationships for a grid of equally spaced points at 1°. It is observed that the maps produced
empirically may be used as a measure of seismic hazard in Turkey. 相似文献
115.
Natural Hazards - Worldwide studies show that gender is an important variable affecting disaster risk perception and that women have high levels of disaster risk perception. The objective of this... 相似文献
116.
Laboratory validation of lattice Boltzmann method for modeling pore-scale flow in granular materials
Characteristics of fluid flow through various engineering structures, such as granular filters and asphalt pavements, influence their design life. Numerical simulation of fluid flow is useful for evaluating the hydraulic characteristics of these materials. Among various techniques, the lattice Boltzmann (LB) method is widely accepted due to the ease of implementing boundary conditions and the numerical stability in a wide variety of flow conditions. It has proven to be extremely efficient in the simulation of fluid flow through the complex geometries of granular materials. In this study, two-dimensional and three-dimensional LB models were developed to represent pore-scale monophasic Newtonian incompressible fluid flow in granular materials. Three-dimensional geometries of compacted aggregates and asphalt specimens were generated from X-ray Computed Tomography technique and used as input for the LB model. The accuracy of the models was verified by comparing the results with analytical solutions of simple geometries and hydraulic conductivity measurements on the compacted aggregates and hot mix asphalt specimens. The results of LB simulations were in excellent agreement with those obtained from analytical calculations and laboratory measurements. 相似文献
117.
In this study, reservoir temperatures of Balıkesir geothermal waters in northwestern Turkey are estimated with various geochemical
models. The geothermal fluids in the region are represented by Na–SO4, Na–HCO3 and Ca–HCO3 type waters with discharge temperatures up to 98°C. It was determined that the solubility of silica in most of the waters
is controlled by the chalcedony phase. Equilibrium states of the Balıkesir thermal waters studied by means of Na–K–Mg–Ca diagram,
mineral saturation calculations and activity diagrams in the system composed of Na2O–CaO–K2O–Al2O3–SiO2–H2O phases approximate a reservoir temperature of about 120°C. Most of the waters are found to be equilibrated with calcite,
chalcedony ± quartz and muscovite at predicted temperature ranges, similar to those calculated from the chemical geothermometers. 相似文献
118.
Melek Isinibilir Ahmet E. Kideys Ahmet N. Tarkan I. Noyan Yilmaz 《Estuarine, Coastal and Shelf Science》2008,78(4):739-747
The monthly abundance, biomass and taxonomic composition of zooplankton of Izmit Bay (the northeastern Marmara Sea) were studied from October 2001 to September 2002. Most species within the zooplankton community displayed a clear pattern of succession throughout the year. Generally copepods and cladocerans were the most abundant groups, while the contribution of meroplankton increased at inner-most stations and dominated the zooplankton. Both species number (S) and diversity (H′) were positively influenced by the increase in salinity of upper layers (r = 0.30 and r = 0.31, p < 0.001, respectively), while chlorophyll a was negatively affected (r = −0.36, p < 0.001). Even though Noctiluca scintillans had a significant seasonality (F11,120 = 8.45, p < 0.001, ANOVA), abundance was not related to fluctuations in temperature and only chlorophyll a was adversely correlated (r = −0.35, p < 0.001). In general, there are some minor differences in zooplankton assemblages of upper and lower layers. A comparison of the species composition and abundance of Izmit Bay with other Black Sea bays reveals a high similarity between them. 相似文献
119.
The Plio-Quaternary conglomeratic sets within the marine environment of the Viranşehir coast (W Mersin, S Turkey) are responsible
for the evolution of sandy and gravely beaches due to their control on various factors such as sea floor irregularity, wave
energy, and organic activity. The conglomeratic sets close to the shoreline (50–150 cm) act as wave breakers, creating hard
substratum and high energy, well-oxygenated environment for organisms like Patella sp., Phoronida worms and Brachidontes pharaonis (Fischer P. 1870). The boring activities of these organisms have disintegrated the sandy matrix of these sets. Finer-grained
matrix sediments have been transported to the interset and open sea, while cobble–pebbles have been carried landwards and
have created imbricated gravely beach deposits without matrix. Sandy beach is evolving where the conglomeratic sets away from
the shoreline (5.0–10.0 m). In this example, sets form a bar; causing fivefold division as backshore, berm, surf zone, bar
and offshore from land to sea. Poorly sorted, cobbles-pebbles cobbles and pebbles are found associated with the high-energy
environments of bars, whilst well-sorted sands are observed in low energetic environments on shore. The sets and recent shell
fragments are the main sources of coastal sediments in Viranşehir. However, the amount of shell fragments decrease towards
the active river mouth. This is due to sediment and fresh water influx from the river causing deteriorated temperature, salinity
and light penetration of the marine environment resulting in less organic diversity.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
120.
Ahmet Erdem 《Celestial Mechanics and Dynamical Astronomy》2002,82(2):133-141
The aim of this work is to search for some evidences for the presence of unseen companion(s) in the eclipsing binary star TV Cassiopeia using its O—C diagram. Assuming that the light-time effect is responsible for the periodic components on the O—C diagram, the set of orbital parameters were derived using Irwin's (1959) method. The resulting orbital parameters and mass of the hypothetical third body are physically acceptable. Lacking other proofs of the third body presence, however, the hypothesis can be treated as a probable case only.This revised version was published online in October 2005 with corrections to the Cover Date. 相似文献