Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 11Citation - Scopus: 11Renewable-Based Treatment Solution of Reactive Blue 21 Dye on Fly Ash as Low-Cost and Sustainable Adsorbent(Elsevier, 2024) Kobya, Mehmet; Dolaz, Mustafa; Goren, Aysegul YagmurThis study investigated the removal of Reactive Blue 21 (RB 21) dye from aqueous solutions by adsorption, evaluating the waste fly ash (FA). The effects of the parameters, such as initial dye concentration (100-750 mg/ L), initial pH (2.0-8.0), adsorbent dose (1.0-4.0 g/L), and temperature (298-323 K) on the adsorption process were investigated. The optimum initial pH value was 2.0 for the highest RB21 dye removal (75.2 mg/g). At optimized conditions (pH 2.0, an adsorbent dosage of 1.0 g/L, a dye concentration of 750 mg/L, and an equilibrium time of 72 h), the highest adsorption capacity was found to be 105.2 mg/g. Moreover, the results of the kinetic studies fitted the pseudo-second-order kinetic model. Equilibrium data were best represented by the Langmuir isotherm model, with a maximum monolayer adsorption capacity of 103.41 mg/g at 323 K. Delta G0ads values were negative and varied from 11.64 to 9.50 kJ/mol in the temperature range of 298-323 K, the values of enthalpy (Delta Ho ads) and entropy (Delta So ads) of thermodynamics parameters were calculated as 37.62 kJ/mol and 86.67 J/mol K, respectively, indicating that this process was endothermic. Furthermore, the adsorbent costs for powdered activated carbon (PAC) and FA to remove 1 kg of RB 21 dye from aqueous solutions are calculated as 2.52 U.S. $ and 0.34 U.S. $, respectively. It is seen that the cost of FA is approximately 7.4 times lower than PAC. The results showed that FA, a low-cost industrial waste, was promising for the adsorption of RB 21 from aqueous solutions.Article Citation - WoS: 10Citation - Scopus: 10Effects of Mixture Design Parameters on the Mechanical Behavior of High-Performance Fiber-Reinforced Concretes(American Society of Civil Engineers (ASCE), 2020) Erdem, Tahir Kemal; Demirhan, Serhat; Yıldırım, Gürkan; Banyhussan, Qais S.; Şahin, Oğuzhan; Balav, Mohammad H.; Şahmaran, MustafaThe main purpose of this research is to assess the influence of different design parameters on the mechanical performance of high-performance fiber-reinforced concrete (HPFRC) mixtures. Special attention is also paid to achieving deflection-hardening behavior in the presence of a large amount of coarse aggregates. Different mixture design parameters were the initial curing ages (3, 7, 28, and 90 days), ratios of Class F fly ash (FA) to portland cement (PC) (0.0, 0.2, and 0.4), addition/type of nanomaterials [nanosilica (NS), nanoalumina (NA), and nanocalcite (NC)], and combinations of fibers [polyvinyl-alcohol + steel (P, S) or brass-coated microsteel + steel (B, S)]. The experimental program included the evaluation of compressive strength, flexural strength, and midspan deflection results in addition to test parameters recorded under biaxial flexural loading via a series of square panel tests, including peak load and energy absorption capacities. Test results revealed that deflection-hardening response coupled with multiple microcracks can be obtained when large amounts of coarse aggregates are available for all HPFRC mixtures. As expected, experimental results change depending on the different curing ages and FA/PC ratios. The most distinctive parameters affecting the results are addition/type of nanomaterials and the presence of different fiber combinations. In the presence of nanomaterials, all results from the different tests improved, especially for NA and NS inclusions. With slight concessions in flexural deflection results, B fiber is shown to be a successful candidate to fully replace costly P fibers because most properties of B, S fiber-reinforced HPFRC mixtures outperformed those with P, S fibers, both under four-point bending and biaxial flexural loading.Article Citation - WoS: 75Citation - Scopus: 87Use of Spent Foundry Sand and Fly Ash for the Development of Green Self-Consolidating Concrete(Springer Verlag, 2011) Şahmaran, Mustafa; Lachemi, Mohamed; Erdem, Tahir Kemal; Yücel, Hasan ErhanIn the United States alone, the foundry industry discards up to 10 million tons of sand each year, offering up a plentiful potential resource to replace sand in concrete products. However, because the use of spent foundry sand (SFS) is currently very limited in the concrete industry, this study investigates whether SFS can successfully be used as a sand replacement material in cost-effective, green, self-consolidating concrete (SCC). In the study, SCC mixtures were developed to be even more inexpensive and environmentally friendly by incorporating Portland cement with fly ash (FA). Tests done on SCC mixtures to determine fresh properties (slump flow diameter, slump flow time, V-funnel flow time, yield stress, and relative viscosity), compressive strength, drying shrinkage and transport properties (rapid chloride permeability and volume of permeable pores) show that replacing up to 100% of sand with SFS and up to 70% Portland cement with FA enables the manufacture of green, lower cost SCC mixtures with proper fresh, mechanical and durability properties. The beneficial effects of FA compensate for some possible detrimental effects of SFS.Article Citation - WoS: 64Citation - Scopus: 70Mechanical and Morphological Properties of Recycled High-Density Polyethylene, Filled With Calcium Carbonate and Fly Ash(John Wiley and Sons Inc., 2006) Atikler, Ulaş; Başalp, Dildare; Tıhmınlıoğlu, FundaIn this study, mechanical and morphological properties of composites made up of recycled high-density polyethylene (HDPE) filled with calcium carbonate and fly ash (FA) were studied. Interfacial interactions were modified to improve the filler compatibility and mechanical properties of the composites by surface treatment of the FA filler with 3-amino propyl triethoxy silane. The composites were prepared by using a Thermo Haake Rheomixer. Effect of filler loading and treatment of FA with silane coupling agent on mechanical and morphological properties were investigated and it was found that silane treatment indicated significant improvements on the mechanical properties of the HDPE-FA composites. The improvement with silane treatment of FA was also confirmed by applying the Pukanszky model. Scanning electron microscopy on the fracture surface of composites had given direct evidence of better interfacial adhesion via silane treatment.