Frequency and Field Dependencies of Susceptibilities of High Tc Superconductor YBCO

The temperature dependence of the first and third harmonic susceptibilities has been measured on a melt-textured YBCO for different frequencies and amplitudes of the ac magnetic field. The behavior of the experimental curves has been compared with the results obtained from the model incorporating both the concepts of Collective Creep and critical state. The predictions of the model for fundamental and third harmonic susceptibilities were consistent with the experimental data.     

Calculation of Levitation Force Using a Critical-State Model

The interaction forces between a permanent disk and a superconductor disk are calculated for a cylindrical system by using the Anderson–Kim model. Model calculations show that both the vertical force and the stability exhibit a peak-like behavior in the repulsive branch. These peaks in the calculations are dependent on the model parameter and the ratio between the penetration and the applied fields, H _p/H _m. The features of hysteretic force and magnetic stiffness are discussed.     

Prioritization methodology of dangerous substances for water quality monitoring with scarce data

Monitoring and control of dangerous substances discharged into receiving waters have attracted more attention lately. Since it is not possible to analyze every single substance, a prioritization methodology is needed for the selection of those to be monitored. Existing well-developed models require significant amount of data for reliable outcomes. This paper presents a methodology to prioritize the dangerous substances having adverse effects on freshwaters in Turkey, where data are scarce. Such a methodology will also serve as a solid model for other countries with limited background data. The adopted methodology enabled the elimination of chemicals to generate a candidate list composed of 608 substances among more than 5000 substances. Further screening and prioritization were conducted using different assessment methods (i.e., Total Hazard Value, Total Impact Value, Combined Monitoring-based, and Modelling-based Priority Setting) to obtain a proposed Final Candidate Specific Pollutants List of 150 dangerous substances. The proposed Candidate National Pollutant List of Turkey was established by combining 45 priority pollutants of the European Union with a list of candidate specific pollutants. According to the outcomes of this study, monitoring and controlling of 195 dangerous substances in freshwaters are recommended. Further detailed studies should be conducted in order to observe the actual levels of these dangerous substances in freshwaters followed by a review of the monitoring list accordingly. Moreover, further revisions might be required in the proposed list due to some possible versatile conditions in terms of sampling points (i.e., change in the location of industries).     

Synthesis of novel acrylic modified water reducible alkyd resin: Investigation of acrylic copolymer ratio effect on film properties and thermal behaviors

New four‐component water reducible acrylic modified alkyd resins that are based on 1,3‐propanediol and contain different ratios of acrylic copolymer (AC) were synthesized by using a novel four‐stage fatty acid method. The final content of solids in the water reducible acrylic modified alkyd resins was 60% by weight. After the modified alkyd resin films were cured at 150°C for 1 h, it was observed that the use of AC as the modifier component had improved their physical and chemical surface coating properties and thermal behaviors. Experimental results show that the optimum AC ratio is 40% of the equivalent amount of AC to alkyd resin. Low‐volatile organic compounds (VOC) content water reducible acrylic modified alkyd resins yielded soft and flexible films with high chemical/thermal resistance, suitable for manufacturing of surface coating binders. POLYM. ENG. SCI., 56:947–954, 2016. © 2016 Society of Plastics Engineers     

Bond strength and adaptation of pulp capping materials to dentin

This study evaluated the shear bond strength (SBS) and internal marginal adaptation of pulp‐capping materials to dentin. Flat occlusal deep dentin surfaces were produced and randomly assigned to two groups (sound or artificial caries‐affected dentin). The specimens in each group were assigned to one of seven subgroups according to the materials used: Biodentine, Theracal LC, Ultra‐Blend plus, Calcimol LC, ApaCal ART, EQUIA Forte, and Ionoseal. Buildups (3‐mm inner diameter and 2‐mm deep) were made over the dentin surfaces. The bonded specimens were tested under shear forces at a crosshead speed of 0.8 mm/min and fracture modes were determined using a stereomicroscope at 25× magnification. The materials were applied to the pulp floor of prepared Class I cavities and then the cavities were restored with composite resin. Restored molar teeth were subjected to 5,000 thermocycles and sectioned in a bucco–lingual direction. Resin replicas were made to determine the adaptation at the pulp floor with scanning electron microscopy. Significant differences were determined among both bond strengths and gap formations of the materials. EQUIA Forte applied to both dentin substrates had a significantly higher SBS than the other materials. The bond strength of each material was not influenced by the dentin condition. Biodentine (3.03%), EQUIA Forte (7.83%), and Theracal LC (13.37%) had lower gap formations compared to other materials but were not significantly different from each other.