The Nucleation Effect of PbSe Additive on Bi2Sr2CaCu2Oδ Glass Ceramics

Glass and Ceramics - The crystallisation kinetics and effects of doping on Bi2Sr2CaCu2Oδ (BSCCO) glass ceramic system with 0.0%, 0.1%, 0.3% and 0.5% PbSe were investigated in this study....     

Organic Carbon and Trace Metal Distribution in the Gökçesu Shale: Eocene Basin,Bolu-Turkey

Abstract

Samples collected from the bituminous shales in the Eocene Tokmaklar formation are the material of this study. Distribution of organic material and trace metals in the shale samples and their concentration levels and correlations were evaluated. Organic carbon content of the bituminous shales is between 0.59 and 15.89% (averaging as 4.86%). The type of organic material is 100% amorphous material (kerogen type is Type I and Type II) and it has a potential to produce oil. Trace metal enrichment levels were determined on the basis of average shale concentration in the earth crust. These levels are divided into two groups. Mo (1.98–2.64), Cu (1.27), As (1.59–8.83), and Sr (2.58–2.75) in bituminous rocks show enrichment character while Pb, Zn, Ba, and Co metals do not display any enrichment. Moreover, comparison with the average values of these metals in seawater and living organisms yield enrichment coefficients of 86.17–386.000 (with respect to seawater) and 4.59–1,723.5 (with respect to living organisms).     

Effect of Zn content on microstructure and mechanical performance in Bi1.8Sr2Ca2Cu3.2−xZnxO10+δ glass ceramic

In this study, we have investigated the effects of Zn doping on structural and mechanical properties of Bi_1.8Sr₂Ca₂Cu_3.2?xZn_xO_10+δ ceramic samples with x = 0.0, 0.1, 0.5, 1.0. The prepared samples were characterized by using scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray powder diffractometer (XRD) and static microhardness indenter. Surface morphology, orientation of grains and elemental composition analysis of the samples were investigated by SEM and EDS measurements, respectively. Texturing and lattice parameters a, b and c were determined from the XRD measurements. In this work we focused on Vickers microhardness measurements in order to characterize the mechanical properties. Experimental results of Vickers microhardness measurements were analyzed by using Meyer’s law, the elastic/plastic deformation model, proportional sample resistance model (PSR), modified PSR model, Hays–Kendall (HK) approach and indentation induced cracking (IIC) model. According to the obtained results, HK approach is the most suitable model for the CZn00 sample showing indentation size effect behavior and IIC Model is the most suitable model for the CZn01, CZn05 and CZn10 samples showing reverse indentation size effect behavior.     

Effects of run‐of‐the‐river hydropower plants on the surface water quality in the Solakli stream watershed,Northeastern Turkey

In recent years, Turkey has turned its attention to alternative energy sources rather than fossil fuels. The Eastern Black Sea Region of Turkey has steep mountains with hilly topography and has large potential in terms of energy production with run‐of‐the‐river hydropower plants (RHPPs). In this study, the effects of two RHPPs on some water quality parameters were examined in the Solakl? stream watershed. This research was conducted over the course of 12 months (January–December 2014). In total, 12 sampling points were selected and various water quality parameters, such as temperature, pH, dissolved oxygen, total suspended solids, electrical conductivity, total dissolved solid, chloride and salinity, were monitered at each point. Statistically, significant changes occured in water quality parameters such as total suspended solids, pH and temperature. In particular, total suspended solids ranged from 10 to 440 mg/L.These results suggest that the RHPP negatively effect water quality and quantity in the main stream in both the operational and constructional phases.     

Analysis of voltage and frequency-dependent series resistance and interface states of Al/ZnCo2O4: Gelatin/n-Si diode

Journal of Materials Science: Materials in Electronics - In this work, which aims to investigate the capacitance and conductance properties of ZnCo2O4-doped Gelatin, 5% ZnCo2O4-doped Gelatin film...     

Effect of Vanadium Substitution on the Dielectric Properties of Glass Ceramic Bi-2212 Superconductor

Glass ceramic superconductors were prepared by the melt-quenching method. The frequency and temperature dependence of dielectric constant (????), dielectric loss (????) and loss tangent (tan???) of these superconductors were investigated in the frequency range of 10 kHz?C10 MHz and temperature range of 80?C300 K using the capacitance?Cvoltage (C?CV) and conductance-voltage (G/w-V) measurements. Effect of vanadium on bulk properties, dc electrical resistivity (??) and ac electrical conductivity (?? _ac) of these superconductors were also investigated. The experimental results showed that ????,???? and ?? _ac were strongly temperature and frequency dependent. Negative capacitance (NC) phenomenon has been observed and it is believed that the negative capacitance effect is due to polarization effect. The results can be concluded to imply that the interfacial polarization can occur more easily at low frequencies consequently contributing to the deviation of the dielectric properties and ac electrical conductivity of Bi₂Sr₂Ca₁Cu₂O _?? and Bi_1.9V_0.1Sr₂Ca₁Cu₂O _?? superconductors.     

Source Rock Evaluation of The Eocene Shales in the Gökçesu Area (Bolu/Turkey)

Abstract

Hydrocarbon potential of oil shale samples from the Gökçesu basin in Bolu, Turkey, was evaluated on the basis of organic geochemical, organic petrographic, gas chromatography, and thin-layer chromatography techniques. Organic materials were found to be oil-producing type (Type I and II kerogen). Thermal maturities, that indicate diagenetic and early mature oil formation stage, were determined with pyrolysis (Tmax), production index (PI), and spore color index (SCI) analyses. The amount of organic material ranging between 0.21 and 15.89% reveals that the unit has variable source rock potentials from weak to perfect. The productivity of the basin was probably high and organic matter preservation was enhanced by a stratified water column. As the basin began to fill with sediment and become shallower, TOC and HI values declined, as the basin water was better oxygenated and preservation conditions declined. On the basis of geologic data, organic geochemical analyses and organic petrographic studies, organic facies of Eocene shales is of AB and B types.     

The Effect of PbSe Addition on the Mechanical Properties of Bi-2212 Superconductors

The effects of PbSe addition and heat treatment on the structure and mechanical properties of Bi-2212 superconductors are analyzed. Glass ceramic method is used to produce PbSe added samples. The mechanical properties are derived using Vickers microhardness measurement results. Well known analysis methods like Meyer??s law, PSR (Proportional Sample Resistance) Model, EDP (Elastic/Plastic Deformation Model), Hays-Kendall approach and IIC (Indentation-Induced Cracking Model) are used to calculate load independent microhardness values of the samples. HK approach produces successful results for the samples A, E, F, G and H indicating ISE (Indentation Size Effect) behavior. The IIC model successfully explains RISE (Reverse Indentation Size Effect) behavior for the samples B, C and D. RISE behavior is observed only for the samples where the plastic deformation is dominant. ISE behavior is observed for the samples where both elastic and plastic deformation are produced. The results of XRD and SEM analysis show improvement with PbSe addition in the crystal structures and surface morphologies of superconducting samples.