Late Pleistocene and Holocene Sea Level Changes in the Hisarönü Gulf,Southeast Aegean Sea

Fluctuations in relative sea level, tectonic movement, and sedimentation during the late Pleistocene to Holocene in the Hisarönü Gulf (SE Aegean Sea) and surrounding area were investigated with a high‐resolution geophysical survey and underwater archaeological observations. The Hisarönü Gulf has been affected by vertical tectonic movements and rising sea level following the last glacial period (20,000 yr B.P.). High‐resolution seismic data were interpreted to reveal the structure of the late Pleistocene to Holocene deposits and determine the location of the paleoshoreline. In order to describe the relative rise of sea level, principles of sequence stratigraphy were used for the late Pleistocene to Holocene transition, and submerged archaeological remains and bioerosional indicators were used for the late Holocene period. A comparison of archaeological observations in the study area with the known regional sea level curve indicates that the relative rise in sea level for the late Holocene is, for the most part, due to the tectonic subsidence of the coastal plain. © 2012 Wiley Periodicals, Inc.     

Development of Predictive Models for the Specific Energy of Circular Diamond Sawblades in the Sawing of Granitic Rocks

This paper presents an experimental study on the sawing of granitic rocks by circular diamond sawblades. The influence of the operating variables and rock properties on the specific energy were initially investigated and analyzed. To determine the most significant operating variables and rock properties influencing the specific energy, statistical analyses were then employed and the models were built for the estimation of specific energy depending on the operating variables and the rock properties. Moreover, the derived models were validated through statistical tests such as the determination coefficient, t-test, F-test, and residuals. The results indicated that the specific energy decreased with the decreasing of peripheral speed and the increasing of traverse speed, cutting depth, and flow rate of cooling fluid, respectively. It was concluded that, rather than the physico-mechanical properties, the mineralogical properties were the dominant rock properties affecting the specific energy. Additionally, the peripheral speed was statistically determined as the most significant operating variable affecting the specific energy. The peripheral speed was followed by the cutting depth, traverse speed, and flow rate of cooling fluid with respect to their level of significance on the specific energy. Furthermore, the model results revealed that the developed models have high potentials as a guidance for practical applications.     

Effects of Operational Parameters on Decolorization of C. I. Acid Red 88 by UV/H2O2 Process: Evaluation of Electrical Energy Consumption

In the present study, effects of operational parameters on the electrical energy consumption for photooxidative process (UV/H₂O₂) for the decolorization of C. I. Acid Red 88 (AR88) have been investigated. In a series of experiments, 20 mg L^?1 of AR88 solution were irradiated in the presence of different concentrations of H₂O₂ (to find out optimum amount of H₂O₂) by UV light intensity of 30 W m^?2 for certain irradiation times. The decolorization of the dye followed pseudo first‐order kinetics, and hence, the figure‐of‐merit electrical energy per order (E_EO) is appropriate for estimating the electrical energy efficiency. The electrical energy consumption was determined during the variation of some parameters such as initial H₂O₂ concentration, initial dye concentration, UV light intensity, pH, and the gap size of solution. Results showed that electrical energy could be reduced by optimizing operational parameters.     

Degradation of Malathion and Parathion by Ozonation,Photolytic Ozonation,and Heterogeneous Catalytic Ozonation Processes

The oxidation of organophosphorus pesticides (OPPs), such as malathion and parathion, in aqueous solution was studied using conventional ozonation (O₃), photolytic ozonation (O₃/UV, O₃/UV/H₂O₂), and heterogeneous catalytic ozonation (O₃/TiO₂/UV) processes. Experiments were performed in batch mode at laboratory scale and processes were compared in terms of disappearance kinetics. The best results of pesticide mineralization were obtained when TiO₂ particles in combination with ozone (O₃) and UV photolysis (λ = 254 nm) were applied. Decomposition of 99% of parent compounds were achieved in 10 min and oxon derivatives were completely removed in 30 min. The initial reaction rate increases linearly with increasing catalyst amount. Toxicity measurements of the treated solutions were carried out in order to evaluate the efficiency of the treatment methods. No detoxification was achieved for O₃ and O₃/UV applications. Heterogeneous photocatalytic ozonation was shown to be feasible for achieving complete decomposition of OPPs and their oxon intermediates.     

Interpretation of Magnetic Anomalies and Estimation of Depth of Magnetic Crust in Slovakia

The magnetic map of Slovakia used in the paper was compiled as part of a project titled Atlas of Geophysical maps and profiles in 2001. The residual magnetic data were analyzed to produce Curie point estimates. To remove distortion of magnetic anomalies caused by the Earth’s magnetic field, reduction to pole transformation was applied to the magnetic anomalies using the magnetization angle of the induced magnetization. Anomalies reduced to the pole tend to be better correlated with tectonic structures. We applied a 3-km upward continuation to the residually compiled magnetic anomalies in order to remove effects of topography. The depth of magnetic dipoles was calculated by an azimuthally averaged power spectrum method for the entire area. Such estimates can be indicative of temperatures in the crust, since magnetic minerals lose their spontaneous magnetization according to Curie temperature of the dominant magnetic minerals in the rocks. The computed Curie point depths in the Slovakia region vary between 15.2 km and 20.9 km. Heat flow higher than 100 mWm⁻² occurs at the central volcanics and eastern part of Slovakia, where the Curie point depths values are shallow. The correlation between Curie point depths, heat flow and crust depth was investigated for two E-W cross sections. Heat flow and Curie point depth values are correlated with each other however, these values could not be correlated with crust depth. The Curie point isotherm, which separates magnetic and non-magnetic parts of the crust, is represented in two cross sections.     

Use of microtremor in liquefaction hazard mapping

This study shows how microtremor measurements can be used as an aid to liquefaction hazard mapping and zonation, as demonstrated in Laoag City, Northern Philippines. From microtremor measurements, qualitative information on subsoil conditions was obtained and a site classification map was generated. The map was combined with the geomorphology-based liquefaction susceptibility map to produce an integrated liquefaction hazard zonation map. This integrated map is deemed to be more accurate in depicting relative liquefaction susceptibility since it combines information on the distribution of potentially liquefiable soils in terms of geology and grain characteristics with information on the stiffness and thickness of these soils. With information about the thickness of the deposits, an idea of the severity of liquefaction-related damage can also be gathered since thicker deposits relate to more serious damage. Plots of historical liquefaction cases, as well as borehole data and resistivity profiles in the study area, support the validity of the integrated map. The use of microtremor, therefore, constitutes an effective and inexpensive approach to liquefaction hazard zonation, and as such is very useful in less-developed countries like the Philippines and other areas where funds for more rigorous investigations are not always available.     

Seismic microzonation and earthquake damage scenarios for urban areas

A methodology for seismic microzonation and earthquake damage scenarios may be considered as composed of two stages. In the first stage, microzonation maps with respect to estimated earthquake characteristics on the ground surface are generated for an investigated urban area. The effects of local geological and geotechnical site conditions are taken into account based on site characterization with respect to representative soil profiles extending down to the engineering bedrock. 1D site response analyses are performed to calculate earthquake characteristics on the ground surface using as many as possible, hazard compatible real acceleration time histories. In the second stage, vulnerability of buildings and pipeline systems are estimated based on site-specific ground motion parameters. A pilot study is carried out to evaluate seismic damage in a district in Istanbul, Turkey. The results demonstrate the significance of site characterization and site response analysis in calculating the earthquake characteristics on the ground surface in comparison to simplified empirical procedures.