Assessment of wind power potential for turbine installation in coastal areas of Turkey

This paper analyses the potential and the feasibility basis for the wind energy resources in some locations of coastal regions of Turkey. The dominant wind directions, the mean values, wind speeds, wind potential and the frequency distributions were determined. The results showed that Bal?kesir and Çanakkale among annual averages show higher value of mean wind speed. The mean annual value of Weibull shape parameter k is between 1.54 and 1.86 while the annual value of scale parameter c is between 2.52 m/s and 8.34 m/s. A technical assessment has been made of electricity generation from four wind turbines having capacity of 600 kW, 1500 kW, 2000 kW and 2500 kW. The yearly energy output and capacity factor for the four different turbines were calculated.     

Ester exchange reactions in polyarylate/poly(ethylene terephthalate) blends

Blends coagulated by a solution/precipitation procedure of a polyarylate (PAr) based on bisphenol A and tere/isophthalates with poly(ethylene terephthalate) (PET) have been studied by a variety of experimental methods. Differential scanning calorimetry experiments have shown that in blends containing more than 30% PET, conditioning of the blends at high temperatures required for calorimetric measurements resulted in progressive ester exchange reactions. The 10% and 20% PET mixtures, in which this extreme conditioning was not required, showed a single glass transition, contrary to the behaviour of the other PET compositions. These differences may be attributed to the shape of the spinodal curve, which has been simulated according to the McMaster model for polymer mixtures. The progression of the interchange reactions has been followed by solvent extraction of the resulting products and subsequent Fourier transform infra-red spectroscopy analysis. A parallel decrease in the PET heat and temperature of fusion in the insoluble fractions was observed. In our opinion this was due to the incorporation of PAr units in the PET chains, which caused a decrease in their crystallizable segment length.     

Mapping potential motorised sightseeing recreation supply across broad privately-owned landscapes of the Southern United States

The recreational opportunities available across landscapes of the Southern United States can be broad and diverse, and collectively are considered a subset of cultural ecosystem services. In describing the settings of recreational opportunities, a number of methods have been proposed that are based in part on geographic information and that can be facilitated by geographical analyses. Presented here are two expedient and cost-effective methods for assessing the recreation supply potential of large, heavily-roaded areas that are situated mainly with privately-owned land in the Southern United States. One land classification process uses fine-scale aerial imagery and other geospatial data in a process that results in three recreational opportunity setting zones with a focus on motorised sightseeing: foreground, background, and remote areas. Within these zones, land cover was derived and aggregated into three major land cover classes, including forest, agriculture, and bare ground classes. Further, a second process uses fuzzy classification methods, and through this highly suitable recreation settings were identified. Each recreational opportunity zone is further subdivided by public- and privately-owned land. We feel these types of recreation setting models can allow managers and planners to gain an understanding of the passive recreation potential of heavily-roaded privately-owned landscapes typical of the Southern United States.     

Esterification of free fatty acids in waste cooking oils (WCO): Role of ion-exchange resins

Although WCO plays a crucial role for the economical production of biodiesel, free fatty acid (FFA) level in the nature of WCO cause saponification problems during transesterification. Acidic ion-exchange resins can be used to decrease WCO free fatty acid level. In this study, activities of resins (Amberlyst-15 (A-15), Amberlyst-35 (A-35), Amberlyst-16 (A-16) and Dowex HCR-W2) in direct FFA esterification were examined in the temperature range of 50–60 °C and the effect of catalyst amount (1–2 wt%) on FFA conversion was also analyzed. FFA conversion increased with increasing reaction temperature and catalyst amount. Order of catalytic activities was found as A-15 > A-35 > A-16 > Dowex HCR-W2. This was related to the size of average pore diameters and magnitude of BET surface area.     

Novel approach in synthesizing ternary GO-Fe3O4-PPy nanocomposites for high Photothermal performance

In this study, graphene oxide-iron oxide-polypyrrole (GO-Fe₃O₄-PPy) ternary nanocomposites having high photothermal activity and stability are synthesized and analyzed using ultraviolet–visible (UV–Vis) spectroscopy, Fourier transform infrared (FTIR), X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and magnetic hysteresis measurement (VSM). The effect of power density (1.5–2.5 W cm⁻²), concentration (0.01–0.2 mg mL⁻¹), and component composition of nanocomposites on the photothermal properties in the near-infrared (NIR) region (808 nm) is examined. The results show that superparamagnetic GO-Fe₃O₄-PPy ternary nanocomposite exhibits excellent photothermal performance. The temperature reaches to 55.5, 72.3, and 83.1 °C under the irradiation of the 808 nm NIR laser at 1.5, 2.0^—, and 2.5 W cm⁻² of power density for 10 min at 0.1 mg mL⁻¹ photothermal therapy (PTT) agent, respectively, and moreover it has excellent photothermal stability. In summary, it is concluded that synthesized nanocomposites potentially may be used in simultaneous magnetic field-guided treatments. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48837.     

New technical combination of seawater and ultrasound wave energy for excavation of highly plastic sticky clays in urban EPB tunneling

In urban tunneling with an earth pressure balance-tunnel boring machine (EPB-TBM), highly plastic clays or sticky clay containing fine-grained sediments makes tunneling conditions more difficult. The proper amount and consistency of the ground conditioning chemicals to be used for the excavation of these difficult or complex geological units are also controversial. Due to the lack of proper management and optimization of such chemical foaming agents in accordance with the excavation material and tunneling method, some environmental impacts may occur. However, environmental pollution and its effects, in other words, the ecological costs emerged as a result of exposure to these chemicals, can sometimes be ignored.

In this study, the use of seawater is proposed as a ground conditioning agent in EPB-TBM operations and the use in addition of ultrasound wave energy application on fine-grained and highly plastic sedimentary clays conditioned with seawater.

Preliminary analyses and evaluations of the new eco-technical combination indicate that the seawater can easily compete with existing sodium-based foaming agent (SLES) on a laboratory scale by providing the required dispersive effect, which can be enhanced with ultrasonic applications.

     

NIR-responsive Fe3O4@PPy nanocomposite for efficient potential use in photothermal therapy

In this work, superparamagnetic Fe₃O₄@PPy nanocomposite with core-shell structure having strong near-infrared (NIR) absorption is synthesized via a facile two-step modified procedure. The prepared nanocomposite samples are characterized by UV–vis, FTIR, SEM, TEM, VSM, and XRD. The effects of laser power density (1.5–2.5 W cm⁻²) and aqueous concentration (0.01–0.2 mg ml⁻¹) of the nanocomposite on the photothermal performance are investigated in the NIR region (808 nm). At 0.1 mg ml⁻¹ concentration, the temperature reaches up to 50.1°C, 64.1°C, and 78.4°C within 10 min, under 1.5 W cm⁻², 2.0 W cm⁻², and 2.5 W cm⁻² NIR laser power density values, respectively. Photothermal conservation efficiency is calculated as 43.9% and the nanocomposite exhibits excellent photothermal stability. In summary, the core-shell Fe₃O₄@PPy nanocomposite is a promising candidate for photothermal therapy and simultaneous magnetic field-guided treatments.