Trace Metal Solid State Speciation in Aerosols of the Northern Levantine Basin,East Mediterranean

An established three stage sequential leach scheme was applied to a series of selected high volume aerosol samples (n = 35) collected from the Turkish Eastern Mediterranean coastline (Erdemli). Samples were selected according to their air mass back trajectory history to reflect the contrasting mixtures of aerosol material present in the Eastern Mediterranean marine aerosol. Two populations were adopted, those samples which were classed as “anthropogenic” and those which were “Saharan” dominated aerosol populations. Applying the three stage leach it was possible to define the proportion for each of the considered metals (Al, Fe, Cu, Pb, Cd, Zn and Mn) present in the (a) “exchangeable” (b) “carbonate / oxide” and (c) “refractory” phases, representing novel solid state aerosol speciation data for this marine system. Clear trends were established, conforming with data from previous studies with mainly crustal derived metals (Al and Fe) being present in the refractory phases (Al > 88%; Fe > 84%) and those influenced by anthropogenic sources being dominating in the exchangeable phase, although for these metals the variability was comparatively high (12–64%; 19–85%; 40–100% for Zn, Pb and Cd, respectively). For the majority, greater exchangeable fractions were present the lower the crustal source contribution to the aerosol population, whereas the “refractory” fraction exhibited contrasting behaviour. This was illustrated by the novel application of the mixing diagram, presenting each of the three speciation stages against the corresponding percent anthropogenic contribution to each collected sample. Zn, Pb and Cd all illustrated progressive decrease in the percent exchangeable with increasing crustal contribution to the aerosol population. The percent exchangeable was discussed in terms of its use to represent the upper limit of the bioavailable fraction of metal associated with the aerosol, post deposition. The mixing diagram approach enabled the prediction of the residual fractions for Cd, Pb and Zn (41 ± 4%; 62 ± 4% and 82 ± 5%, respectively,) in Saharan end-member material.     

Origin and source regions of PM10 in the Eastern Mediterranean atmosphere

A set of daily PM₁₀ (n = 281) samples collected from April 2001 to April 2002 at a rural site (Erdemli), located on the coast of the Eastern Mediterranean, were analyzed applying Mass Closure (MC), absolute principal factor analysis (APFA) and Positive Matrix Factorization (PMF) to determine source contributions. The results from the three techniques were compared to identify the similarities and differences in the sources and source contributions. Source apportionment analysis indicated that PM₁₀ were mainly originated from natural sources (sea salt + crustal ≈ 60%) whilst secondary aerosols and residual oil burning accounted for approximately 20% and 10% of the total PM₁₀ mass, respectively. Calculations for sulfate showed that on average 8% and 12% of its total concentration were originated from sea salt and biogenic emissions, respectively. However, the contribution by biogenic emissions may reach up to a maximum of ~ 40% in the summer. Potential Source Contribution Function (PSCF) analysis for identification of source regions showed that the Saharan desert was the main source area for crustal components. For secondary aerosol components the analysis revealed one source region, (i.e. the south-Eastern Black Sea), whereas for residual oil, Western Europe and the western Balkans areas were found to be the main source regions.     

The Effect of the Propeller Jet on Pile Groups简

The objective of this study is to determine the effect of jet propeller on the damage of berthing structures combined of armoured slope with pile groups. For this purpose, scour measurements were performed for four types berthing structures, which were armoured slope with tandem arrangements of piles for two and three piles and with side by side arrangements of piles for two and three piles. The effect of gap between piles on damage was investigated. The damage level induced by propeller jet between piles was determined. The gaps were 1, 2, 3, and 4 times the pile diameter. Three different values of Rpm （690, 820, and 950） were chosen for the tests. The diameter of circular piles is 40 mm. The slope ratio was 1/3 and the diameter of propeller was 10 cm.     

Dynamic Responses of Block Type Quay Walls Under Cyclic Loading

The purpose of this research is to study the dynamic responses of gravity quay walls with block type consisting of“three blocks”experimentally.For this purpose,1g shaking table tests were conducted under different cyclic loadings for two different saturated granular backfill materials(Soil 1 and Soil 2).In this study,D_n50 of Soil 1 and Soil 2 are selected as 2.2 cm and 1.0 cm,respectively.During the experiments,accelerations,soil pressures and displacements were measured for each block.Test results pointed out that Soil 2 caused more damage on structures.The measurements for displacement and tilting of each block were discussed in view of“acceptable level of damage in performance-based design”given in PIANC(2001).The result of the study showed that the definitions of damaged levels given in PIANC(2001)were reliable for using in performance-based methods for seismic design of block type quay walls.     

An integrated earthquake damage assessment methodology and its application for two districts in Istanbul, Turkey

This paper presents an integrated, earthquake-damage assessment that standardizes and quantifies methods of analysis. The proposed methodology evaluates all damage-causing phenomena, both individually and in combination. This approach inherently relates to soil-structure interactions by quantifying site-specific geotechnical and structural properties. Specifically considered is ground shaking, the primary damage-causing phenomenon. Also evaluated are the collateral effects of liquefaction, degradation of seismic-bearing capacity and slope failure (landslides). The methodology incorporates a literature-derived probabilistic assessment of damage-causation, and is interpreted and presented as single numbers deemed “Damage Grades.” These damage grades integrate the initial probabilistic evaluation with professional experience and judgment in order to determine potential damage to a particular structure at a particular location. This methodology was applied, with success, to two different locations in Istanbul, Turkey. It should be tested by engineering geologists and geotechnical engineers, for it may be applicable to earthquake-prone areas elsewhere.     

Behavior of homogenous rubble mound breakwaters materials under cyclic loads

Rubble-mound breakwaters are subjected not only to water wave action but also to other types of environmental loading, such as earthquakes. The design of coastal structures should take into account the most relevant factors in each case, including seismic loading. The purpose of this study is to understand the dynamic response of breakwater materials in dry and water conditions. Hence, an experimental study was carried out for homogeneous breakwater structures subjected to different dynamic loadings with variable frequencies and amplitudes in a shaking tank. A shaking tank with a single degree of freedom was developed. The experiments were performed with rigid bottom conditions. The model scale was 1/50. The cyclic responses of the breakwater made of entirely armor material and another of entirely core material were examined separately, and their behaviors were then compared. The experimental results are also discussed with a numerical study, and the material properties and failure modes were thus defined. It is found that the settlement of the armor and core materials under cyclic loads increased with increasing base acceleration level. The cyclic deformation of the rubble mound breakwater in water was larger than that under dry conditions. The cyclic deformation of the rubble materials resulted in crest lowering and slumping. Dominant mode of the seismic failure was associated with the settlement of the crown of the structure accompanied by densification of the core material.