Determination of radioactivity levels in Akhisar,Gördes,Gölmarmara and Sindirgi regions,Western Turkey

In this study, radioactivity measurements in the environment of Akhisar, Gölmarmara, Gördes and Sindirgi regions in Western Turkey were investigated in order to evaluate the implications of any excess radioactivity in the environment of geological formation. The radioactivity concentrations of ⁴⁰K, ²³⁸U and ²³²Th radionuclides in the soil samples were measured by a NaI(Tl) gamma spectrometer system, and the radium activity concentrations in the water samples were also analyzed by an ZnS(Ag) alpha counter by the collector chamber method. The radioactivity of ⁴⁰K, ²³⁸U and ²³²Th in soils ranged 2.80–2,347.77, 9.90–256.19 and 9.66–106.53 Bq kg^?1, respectively. The activity of ²²⁶Ra in the water samples ranged from 0.03 Bq L^?1 (0.89pCi/L) to 0.80 Bq L^?1 (21.58pCi/L). In addition, the external terrestrial gamma dose rate in air (nGy h^?1), annual effective dose rate (mSv year^?1) and radium equivalent activity (Bq kg^?1) were calculated and compared with international standard values.     

Exploration of S-wave velocity profiles at strong motion stations in Eskisehir,Turkey, using microtremor phase velocity and S-wave amplification

We have explored 1D S-wave velocity profiles of shallow and deep soil layers over a basement at strong motion stations in Eskisehir Province, Turkey. Microtremor array explorations were conducted at eight strong motion stations in the area to know shallow 1D S-wave velocity models. Rayleigh wave phase velocity at a frequency range from 3 to 30 Hz was estimated with the spatial autocorrelation analysis of array records of vertical microtremors at each station. Individual phase velocity was inverted to a shallow S-wave velocity profile. Low-velocity layers were identified at the stations in the basin. Site amplification factors from S-wave parts of earthquake records that had been estimated at the strong motion stations by Yamanaka et al. (2017) were inverted to the S-wave velocities and Q-values of the sedimentary layers. The depths to the basement with an S-wave velocity of 2.2 km/s are about 1 km in the central part of the basin, while the basement becomes shallow as 0.3 km in the marginal part of the basin. We finally discussed the effects of the shallow and deep sedimentary layers on the 1D S-wave amplification characteristics using the revealed profiles. It is found that the shallow soil layers have no significant effects in the amplification at a frequency range lower than 3 Hz in the area.     

Selective Preconcentration of Trace Amounts of Cu(II) With Surface‐Imprinted Multiwalled Carbon Nanotubes

In this study, a new sorbent is synthesized using surface imprinting technique. Cu(II)‐imprinted multiwalled carbon nanotube sorbent (Cu(II)‐IMWCNT) is used as the solid phase in the solid‐phase extraction method. After the preconcentration procedure, Cu(II) ions are determined by high‐resolution continuum source atomic absorption spectrometry. A total of 0.1 mol L^?1 ethylenediaminetetraacetic acid (EDTA) is used to remove Cu(II) ions from the sorbent surface. The optimum experimental conditions for effective preconcentration of Cu(II), parameters such as pH, eluent type and concentration, flow rate, sample volume, sorbent capacity, and selectivity are investigated. The synthesized solid phase is characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The maximum adsorption capacities of Cu(II)‐IMWCNT and non‐imprinted solid phases are 270.3 and 14.3 mg g^?1 at pH 5, respectively. Under optimum experimental conditions for Cu(II) ions, the limit of detection is 0.07 μg L^?1 and preconcentration factor is 40. In addition, it is determined to be reusable without significant decrease in recovery values up to 100 adsorption–desorption cycles. Cu(II)‐IMWCNT have a high stability. To check the accuracy of the developed method, certified reference materials, and water samples are analyzed with satisfactory analytical results.     

A statistical analysis of seismo-ionospheric TEC anomalies before 63 <Emphasis Type="Italic">M</Emphasis><Subscript>w</Subscript> ≥ 5.0 earthquakes in Turkey during 2003–2016

In this study, pre-seismic and post-seismic total electron content (TEC) anomalies of 63 M_w?≥?5.0 earthquakes in Turkey (36°–42°N, 26°–45°E) were statistically investigated. The largest earthquake that occurred in Turkey during 2003–2016 is the M_w 7.1 Van earthquake on October 23, 2011. The TEC data of epicenters is obtained from CODE-GIM using a simple 4-point bivariate interpolation. The anomalies of TEC variations were determined by using a quartile-based running median process. In order to validate GIM results, we used the GPS-TEC data of available four IGS stations within the size of the Van earthquake preparation area. The anomalies that are detected by GIM and GPS-TEC show a similar pattern. Accordingly, the results obtained with CODE-GIM are reliable. The statistical results show that there are not prominent earthquake precursors for M_w?≤?6.0 earthquakes in Turkey.     

A combined polarizing microscope,XRD, SEM,and specific gravity study of the petrified woods of volcanic origin from the Çamlıdere-Çeltikçi-Güdül fossil forest,in Ankara,Turkey

The fossil forest in the Çaml?dere-Çeltikçi-Güdül region of the province of Ankara in Turkey has a large number of petrified coniferous and oak tree remains. Petrification occurred in volcanic ashes and tuffs with permineralization, and Fe, Mg, Ca and Ni ions played important roles in the substitution of Si for C. However, the petrified wood samples are heterogeneous in colouration, weight, toughness, and durability, despite being obtained from the same source. Those features are very important for end-users because petrified woods, if cut and polished, are used widely as both decorative indoor tiles and gemstone objects, but heterogeneous materials suffer large wastage while they are being worked and used.Chemical analyses, specific gravity measurements, polarizing microscope studies, X-ray diffraction patterns, and scanning electron image evaluations were performed to classify and identify the homogenous material of the petrified woods relating to its physical and mineralogical characteristics.The different characteristics of the petrified wood samples are due to their varying inner structures, which depend on the replacement silica-building phases and their ratios, and silica particle sizes. Thin sections and XRD patterns revealed that petrified woods in the region were silicified by replacement with both chalcedonic quartz components, including chalcedony (length-fast quartz), moganite and orthorhombic-silica (length-slow quartz), and opalline quartz components including opal-CT and opal-C (length-slow quartz). The scanning electron microscope images were shown that the internal structures of the petrified woods consist of mostly submicron-sized (100–800 nm), and partially nano-sized (60–120 nm) silica-building particles.So, the petrified wood samples can be firstly classified into five main-groups based on their colourations and specific gravity values, then, into three sub-groups based on the principal chalcedonic and opalline quartz silica-building phases and related particle sizes, and also weighing, toughness, and durability. In the first group (samples 1, 2, and 3), the crystallinity gradation of the petrified woods can be classified as quasi-coarse crystalline because they include mainly chalcedony and moganite phases with 800–200 nm ranging in particle size. They are heavy, tough, and resistance as a material, as shown by specific gravity values of 2.60, 2.56, and 2.54, respectively. In the second group (sample 4), the crystallinity gradation of the petrified wood can be classified as quasi-fine crystalline because it includes mainly o-silica and moganite phases with 400–100 nm ranging in particle size. It is medium-heavy, semi-tough and quasi-resistance as a material, as shown by a specific gravity value of 2.42. In the third group (sample 5), the crystallinity gradation of the petrified wood can be classified as quasi-nano-crystalline because it includes mainly opal-CT and opal-C phases with 120–60 nm ranging in particle size. The material is slight, brittle, and weak as a material, as shown by a specific gravity value of 2.18.Ultimately, in the petrified wood found in the Çaml?dere-Çeltikçi-Güdül region of Ankara province in Turkey, it is revealed that samples 1, 2, and 3 represent flint and chalcedony quartz mineral species, samples 4 and 5 represent chalcedony and opal quartz mineral species.     

Controlling factors of recent clastic coastal sediments (Viransehir,Mersin bay,S Turkey)

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.     

Contemporary surface wind climatology of Turkey

The aim of this study was to examine the climatological characteristics of boundary layer gradient winds in Turkey in detail. In the study, monthly average wind speed (V _m) data measured at 267 stations for the 16 directions, prevailing wind direction (V _p), and station pressure (P _s) data measured at 174 stations during the period 1970–2008 by the Turkish Meteorological Service (TMS) were used. The data were provided by the TMS. To attain the aim of the study, wind patterns of midseason months representing the seasonal wind distributions were used, and surface wind formations were examined through calculation of divergent and rotational components of the average wind rate. Besides, it was aimed at explaining the relationships between sea level pressure (SLP) patterns and wind formations. The patterns of midseason months were examined via the Principal Component Analysis (PCA). In accordance with V _m data, it is seen that air flows in Turkey generally tend to orientate radially from west to east. Climatologically, the strongest prevailing winds in Turkey blow during the summer months, while the weakest winds blow during the autumn months. V _m and V _p distributions show a parallelism (i.e., wind gradient) in the months during which temperature differences between land and sea are high due to the differences in their specific heat values. The distributions of V _m and V _p values vary considerably in spring and autumn months during which temperature differences are relatively lower. According to the PCA results, the first two components represent the strong wind areas in Turkey. These components presumably explain the existence of coherent wind formation areas, which display different characteristics due to regional physical geographical factors and processes (e.g., orography, altitude, exposure, land–sea distribution, surface mechanical and thermodynamic modifications of the air masses and air flows, etc.) in addition to the direct effect of different synoptic-scale pressure and circulation conditions.     

Optimum characteristic properties of isolators with bilinear force–displacement hysteresis for seismic protection of bridges built on various site soils

In this study, closed form equations as functions of the isolator, bridge and ground motion properties are formulated to calculate the optimum characteristic strength, Q_d and post-elastic stiffness, k_d, of the isolator to minimize the maximum isolator displacement (MID) and force (MIF) for seismic isolated bridges (SIBs). For this purpose, first, sensitivity analyses are conducted to identify the bridge, isolator and ground motion parameters that affect the optimum values of Q_d and k_d. Next, for the identified parameters, nonlinear time history analyses of typical SIBs are conducted to determine the optimum values of Q_d and k_d for a wide range of values of the parameters. Next, nonlinear regression analyses of the available data are conducted to obtain closed form equations for the optimum values of Q_d and k_d, to minimize the MID and MIF. The equations are then simplified for various site soil conditions. It is observed that the optimum Q_d and k_d are highly dependent on the site soil condition. Furthermore, the optimum Q_d is found to be a linear function of the peak ground acceleration.