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In this study, photocatalytic degradation of 2,4 Dichlorophenoxyacetic acid (2,4D), one of the the most used pesticide, was investigated by TiO2 photocatalyst produced by sol-gel method. Three different parameters (Titanium isopropoxide (TIP) amount, HNO3 concentration and aging time) were investigated and modelled by applying Box Behnken Experimental Design method for optimum TiO2 synthesis. Photocatalyst production process was optimized by examining the 2,4D photocatalytic degradation rate of TiO2 photocatalysts produced under different process conditions. TiO2 samples, which were synthesized with the optimum conditions, were characterized by XRD (X-ray Diffraction), SEM (Scanning Electron Microscope), zeta potential, particle size analysis, and also compared with commercial Degussa P25 TiO2 photocatalyst. 2,4D photocatalytic degradation rate was determined as 0.0084 min-1 for the optimum condition 1 (TIP amount: 24.08 mL, HNO3 concentration: 3.53 M, aging time: 2.29 hours) and 0.0085 min-1 for the optimum condition 2 (TIP amount:10.33 mL, HNO3 concentration: 0 M and aging time: 19.51 hours). The amount of used acid was reduced to zero or the aging time was reduced to the lowest value (2.29 h) by optimizing the TiO2 production parameters via experimental design methodology, hence, a very high photocatalytic efficiency was obtained. [ABSTRACT FROM AUTHOR]

Adhesion it is known that the bond strength varies depending on the interaction of the material surfaces with each other and the surface morphology of the samples. Sufficient surface conditions are required to achieve good adhesion. It is important how the surface morphology, roughness values and free surface energy (SFE) values affect the bond strength and the relationships between these values. The aim of this study was to investigate the relationship between surface morphology, roughness values, contact angle and SFE values of hybrid etched surfaces with chemical etching, sandblasting and both sandblasting and chemical etching. Different surface morphologies were formed of the surfaces etched with different techniques. Contact angle values were determined by using different liquids on the surface of the samples with different surface morphologies. In addition, the surface morphology of the etched AA7075 samples was analyzed by scanning electron microscope (SEM) and 3D profilometer, and surface roughness values were determined.Different surface morphologies of the etched surfaces were formed by different techniques. The SFE values of the surfaces give us information about how wettable the surface is. For this reason, the surface roughness andn SFE values of AA7075 surfaces were compared and the mechanical and thermodynamic relations of the surfaces were revealed in the study. OWRK and Zisman methods were used in the calculations of SFE and it was seen that the values obtained from the two methods were consistent with each other. The highest SFE values were obtained on hybrid etched surfaces with sandblasting+0.5M NaOH and sandblasting+1M NaOH. Surface roughness values took different values in each surface treatment. As a result, it is seen that there is no direct relationship between surface roughness values and SFE. [ABSTRACT FROM AUTHOR]

In the study, the removal performance of arsenic and antimony by drinking water treatment sludge (DWTS) was investigated. DWTS-200 was produced by thermal modification of the DWTS at three different temperatures (200, 400 and 600℃). The maximum arsenic removal was obtained at 200℃ and 1 hour contact time. The surface area and pore volume of adsorbent were analyzed by BET method; phase compositions were determined by X-ray diffraction (XRD), surface morphologies and elemental analyses were performed by scanning electron microscope (SEM) and energy disperse X-ray spectroscopy (EDS). The results showed that adsorbent had a relatively high surface area (170 m2 g-1) and was predominantly amorphous. The predominant phases were iron, calcite, oxygen, and quartz. The breakthrough volumes were obtained as 6,000 L (133,000 BV) and 640 L (14,000 BV) for 40 μg As L-1 and 80 μg Sb L-1 inlet concentrations. In order to determine the kinetic parameters and predict the breakthrough curves for column design, Thomas and Yoon-nelson models were applied. The column experimental data were fitted well to each model. The maximum adsorption capacity was calculated by Thomas model as 6.53 mg Asg-1, 5.21 mg Sbg-1. Regeneration studies were also shown that DWTS-200 could be reused after regeneration. [ABSTRACT FROM AUTHOR]

Expanded polystyrene (EPS) trays are widely used for food packaging and serving because they are light and inexpensive. However, their use has been banned or restricted in many parts of the world due to its negative effects on the environment. In recent years, many studies have been carried out on the production of biodegradable foam trays. Although starch-based foam trays are promising in terms of being biodegradable and having sufficient mechanical resistance, the most important obstacle in their commercial use is that they are not sufficiently resistant to water. In this study, foam trays were produced by adding wheat fiber at a ratio of 7% of starch after wheat starch or mixture of wheatpotato starch was cross-linked with glyoxal. Foam trays were coated by using solutions of polylactic acid (PLA), polycaprolactone (PKL), and polymethyl methacrylate (PMMA). Scanning electron microscope images showed that coating materials formed a 30-40 µm thick layer on the surface of foam trays and making the surface of trays smoother. The average density of foam trays produced from wheat potato starch was 0.120±0.01 g/cm3, which was lower than that of trays produced from wheat starch (0.157±0.02 g/cm³ ). The coating of trays produced from wheat starch with PKL and PLA, and wheat-potato starch with PLA and PMMA did not change the density of trays. Foam trays coated with PLA and PMMA absorbed 12 and 18 times less water than control trays, respectively. The trays made of wheat-potato starch coated with PMMA absorbed only 2.3% of water after 300 minutes, showing that they could be particularly suitable for packaging foods with a high water content. Trays coated with PCL under simulated soil were found to break down on the day 42, and those coated with PLA on the day 84. It was determined that 12.2% of the initial tray weight of trays coated with PMMA remained intact on the 84th day. [ABSTRACT FROM AUTHOR]

In this study, sodium alginate/poly (vinyl alcohol)/clinoptilolite composite membrane was obtained for the separation of dimethylformamide/water mixture by pervaporation method. Cross-linked membranes were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and scanning electron microscope (SEM) instruments. Although the flux value (3.266 kg/m2 h) was found to be high, the desired result for selectivity could not be achieved. The activation energy for the 20% by weight DMF solution was measured as 3,720 kcal/mol. The effect of zeolite addition on membrane performance was investigated. [ABSTRACT FROM AUTHOR]

In this study, the effect of gas cementation, tempering and deep cryogenic treatment with different holding times (24, 36, 48 hours at -196 °C) on the corrosion behavior of cementation steel in 3,5% NaCl environment was investigated. The corrosion tests of the samples classified in five different groups were examined with the Electrochemical Impedance Spectroscopy (EIS) method, the degradation of the metal surface was visually investigated with the Scanning Electron Microscope (SEM), and the chemical composition of the surface was determined by Energy Dispersive X-ray Spectroscopy (EDS). The findings show that cementation, tempering and cryogenic treatment applications reduce the corrosion rate of cementation steel. It has been demonstrated by electrochemical and surface imaging methods that the N3 sample, which applied deep cryogenic treatment with 24 hours holding time after cementation, is much less corroded in 3,5% NaCl environment than other samples. [ABSTRACT FROM AUTHOR]

Magnesium alloys; It is widely used in metallic biomaterials with its low toxic effect and biodegradability. Although these alloys help the formation of new tissues in the body, they provide great advantages over other metallic biomaterials due to their ability to dissolve from the body after the area of use has healed. However, due to their low corrosion resistance, they cause it to dissolve in the body before the treatment process is completed. This is the major disadvantage that limits the use of magnesium alloys. Various surface modification methods are applied to magnesium alloys in order to eliminate this disadvantage. Micro Arc Oxidation (MAO) method, which can provide a coating resistant to wear and corrosion, is one of the surface modification methods applied to improve the surface properties of magnesium alloys. In this study; Composite oxide coatings with Ag nanoparticle and Hydroxyapatite were grown by MAO method. Morphological properties of the coatings were determined by Scanning electron microscope and X-Ray Diffraction instruments. The antibacterial properties of Ag nanoparticle and HA doped composite oxide layer which were grown by MAO method and the biodegradability of the coated/uncoated materials in the blood plasma were investigated. As a result of the experiments, the development of bacterial activity in the sample coated by MAO was prevented by adding Ag nanoparticle and Hydroxyapatite to the electrolite solution. In addition, the biodegradation rate has been reduced by surface treatment on AZ91 Mg Alloy. As a result of the soaking test in blood plasma, it was determined that AZ91 Mg alloy protects itself against dissolution with a rate of approximately 89%. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study is to evaluate the bond strength of different repair systems by using composite resin and ceramic cementation repair methods to zirconia-based ceramics. Material and Method: All-ceramic blocks (IPS Empress II; Ivoclar Vivadent, Schaan, Liechtenstein) sized 4.00 mm in length, 5.4 mm in width, and 3.00 mm in height were fabricated by dental laboratory as thirty specimens. CAD/CAM zirconia blocks (n =40) (Prozir; SeramDent, Turkey) sized 5.00 mm in length, 5.4 mm in width and 13.0 mm in height by CEREC System were fabricated from fully sintered Y-TZP core. Zirconia specimens were randomly divided into seven groups for the following different intraoral repair systems(Clearfil, Cimara Zircon, Bisco) and a control group. Every ten specimens were repaired as same sized. Control group was fabricated by conventional firing as unbroken solid zirconia ceramic samples. Each specimen underwent 5000 cycles of thermocycling. The SBSt (Shear bond strength test) was performed by loading force on the repaired piece to record load-to-failure. Failure mode was evaluated using a digital microscope and SEM. SBSt data were analyzed using one-way ANOVA and Tukey’s HSD test. Results: Clearfil and Cimara Zircon systems significantly increased the bond strength for composite resin method when compared with the Bisco system (respectively p <0.001, p =0.001). All-ceramic method significantly increased the bond strength when compared with the composite resin in Bisco system (p <0.001). Conclusion: Although the composite restoration method is effective for repair, the all-ceramic/zirconia repair method can be an option for repairing layered zirconia restorations. [ABSTRACT FROM AUTHOR]

In this study, additive manufacturing technique was preferred to produce Wolfram (W), Silicon (Si), and Molybdenum (Mo) doped Co-Cr biomedical alloy. In biomedical applications, the alloy consisting of Wolfram (W), Silicon (Si), Molybdenum (Mo), Chromium (Cr), and Cobalt (Co) elements as known for its high wear and good corrosion resistance. Two group of Co-Cr-Mo alloys were produced using the Selective Laser Melting (SLM) method, one of the additive manufacturing manufacturing techniques. One of the produced samples was then subjected to a secondary heat treatment process. The microstructures of the produced alloys were investigated using X-Ray diffractometry (XRD), Energy dispersive X-Ray analysis (EDX) and scanning electron microscope (SEM). Then, the mechanical properties of the alloys were analyzed by electrochemical corrosion test, microhardness test and Archimedes principle density measurement were the final tests. The data obtained as a result of the analyzes showed that a homogeneous microstructured Co-Cr-Mo alloy was produced by the additive manufacturing production technique. In addition, heat treatment caused serious changes on the microstructure and mechanical properties of the material. The most important of these changes was the reduction of the grains forming the alloy, resulting in an increase in the microhardness value of the alloy. [ABSTRACT FROM AUTHOR]

In this study, the CuO thin films were deposited on glass substrates at different substrate temperatures (350, 400, 450, and 500 C) by the ultrasonic spray pyrolysis (USP) method and then annealed at 525 C. In X-ray diffraction (XRD) analysis, the peak intensity was not found in thin films at 350 C substrate temperature and as-grown conditions. Two distinct peaks were observed at 36 and 39 in the XRD patterns of other films. These peaks are characteristic peaks of the monoclinic crystal structure of CuO. Atomic force microscopy (AFM) and scanning electron microscope (SEM) images of the produced thin films were examined. The surfaces of thin films are not smooth. After annealing, grain agglomerations were formed. The optical properties of the CuO thin films were analyzed by ultraviolet-visible region (UV-Vis) measurements. Forbidden band gap values (Eg) were calculated from Tauc graphs for as-grown and annealed samples. It has been observed that the structural, morphological, and optical properties of CuO thin films produced by the USP method can be controlled by the substrate temperature. [ABSTRACT FROM AUTHOR]

In this study, an electrochemical sensor based on carbon nanotube immobilized with diester-functionalized calix[4]arene (CNT-Calix-DE) was developed to determine the ondansetron content in pharmaceutical preparations. During the sensor preparation stage, the glassy carbon electrode surface was modified with CNT-Calix-DE. The surface morphology, electrochemical characterization and analytical performance of the sensor were examined using scanning electron microscope (SEM), electrochemical impedance spectroscopy (EIS) and differential pulse anodic stripping voltammetry (DPASV). Under optimal experimental conditions, the developed sensor showed a linear response to ondansetron in the concentration range of 1.0-10.0 M. Analytical applicability of the sensor was investigated by determination of ondansetron in pharmaceutical preparations. [ABSTRACT FROM AUTHOR]

In this study, the effects of the addition of chia and flaxseed gel as egg white replacers on the rheological properties of pancake batter and some quality properties of pancake samples were investigated. Chia and flaxseed gel were used in two different proportions (50%, 100%) as egg white replacers. It has been revealed that the flow behavior properties of pancake batters can be explained by the power law model (R2=0.987-0.998) and the samples exhibited shear-thinning behavior. The use of chia and flaxseed gel increased the elastic (Gˈ) and viscous modulus (G") values. It was determined that the protein content decreased with increased ratio of chia and flaxseed gel (P <0.05). By examining the scanning electron microscope images, porosity of the samples decreased with the increase of chia and flaxseed gel, and the samples showed a more layered and fragile structure with the increase of chia seed gel. [ABSTRACT FROM AUTHOR]

In this study, it is aimed to produce nanofibers via electrospinning method using a polymer solution doped with β-arbutin, which is known as an agent reducing skin blemishes. For this purpose, β-arbutin was added to the polyamide 6/formic acid solution with chosen concentrations as 2%, 5%, and 10% (w/v). After preliminary electrospinning process, scanning electron microscope (SEM) analysis was performed to determine the optimum spinning parameters. The SEM images presented that nanofibers with uniform morphology were obtained with the 2% (w/v) β-arbutin concentration. Three different voltages were applied for 2% (w/v) β-arbutin added solution and the best morphology was obtained by 30 kV voltages. According to the statistical analysis performed, it was seen that the mean diameters of nanofibers varied due to the β-arbutin concentration. In this study, it has been demonstrated that the thin and light nanofiber textile surfaces containing skin blemishes reducing agent can be produced via electrospinning method to be used as a cosmetic textile product. [ABSTRACT FROM AUTHOR]

Magnetite (Fe3O4), Humic Acid (HA) and Silver (Ag) are materials with important properties. Synthesizing a single material which will have all the properties of these materials can provide significant advantages for some application areas. In this study, synthesized Fe3O4@HA@Ag was doped into poly(vinyl pyrrolidone) (PVP), in weight ratios of 5%, 7.5% and 10%, and nanofiber production was carried out by electrospinning method. Structural properties of nanofiber structures were investigated by X-ray Diffraction (XRD), morphological properties by Scanning Electron Microscope (SEM), spectroscopic and thermal characterizations by Fourier transform infrared (FTIR) and Thermogravimetric Analysis (TGA). When the analysis results of nanofibers were evaluated, it was determined that Fe3O4@HA@Ag doped PVP nanofibers were successfully produced. [ABSTRACT FROM AUTHOR]

In the study, the micromorphology of labellum in samples belonging to 10 different Ophrys taxa was examined by Scanning Electron Microscopy (SEM) method and the results were presented in comparative tables. While the samples were collected from the field, they were taken to 70% alcohol, some of them were dried according to the herbarium rules and identified. The labellum samples extracted from alcohol were dissected under the stereomicroscope with scalpel and needles and placed directly into the iron apparatus of the SEM device with double-sided adhesive tapes. These samples, whose alcohol was completely evaporated by waiting for one night, were examined directly with Scanning Electron Microscope (SEM) and labellum microphotographs were taken. According to our findings, it was determined that the speculum structures are very different from each other, and the shape and distribution of the hair / papilla in the basal, median and lateral regions differ from species to species.It was also determined that the apex region differs in O. fusca, O. lutea, O. speculum, O. mammosa, O. pseudomammosa, O. heldreichii, O. umbilicata, and O. holoserica species. In summary; It was concluded that the labellum speculum and apex structure of the 1st degree and the basal, median and lateral region surface characteristics of the 2nd degree differ widely between the species. [ABSTRACT FROM AUTHOR]