Yazar "Toptas, Yeliz" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • Küçük Resim Yok
    Öğe
    Implementation of Taguchi method, ANOVA and regression analyses to enhance char yield by carbonization in lignite-biomass blended
    (Taylor & Francis Inc, 2024) Korkmaz, Aydan Aksogan; Toptas, Yeliz
    Energy is a basic need for modern societies. Renewable energy refers to producing and using energy without harming the environment and without consuming resources. The transition to renewable and sustainable energy can provide many environmental, economic and social benefits. Academic research plays an important role in achieving this transition. Sustainable energy is critical to protecting the environment, promoting economic development and supporting social improvements. The transition to sustainable energy is a necessity for the future of humanity. For this purpose, in this study, lignite and biomass (apricot kernel shell) carbonization experiments were carried out under different conditions. Mixing ratio (Lignite/Biomass (w/w 1:1, 1:2, 1:3)), temperature (400 degrees C, 500 degrees C, 600 degrees C) and heating rate (10 degrees C/min, 30 degrees C/min, 50 degrees C/min) were determined as variable parameters. Taguchi's experimental design was used to optimize the parameters. The orthogonal array design plan was determined as L9 according to the available variables (33 x 33). Since the study aimed to obtain clean solid fuel, char yields were taken into account from the results. Signal-to-noise (S/N) ratios were calculated based on the larger the better condition. As a result of the carbonization experiments performed under Taguchi optimization conditions, it was determined that the S/N ratio was 31.73 and the char yield was 40.19%. Since the estimated char yield with the Taguchi method was 38.85%, it was concluded that the optimization was achieved with 96.67% accuracy. The test parameters satisfying these conditions were determined as 1:1 lignite/biomass mixing ratio, 400 degrees C temperature and 30 degrees C/min heating rate. As a result of the ANOVA analysis, it was seen that the heating rate did not have a significant effect on these parameters. In contrast, the temperature and mixing ratio were important variables. Also, regression analysis (linear and quadratic) was used in this study to calculate the equations for the prediction of char yield. It was concluded that the linear regression model was more successful in estimating the char yield.
  • Küçük Resim Yok
    Öğe
    A molecularly imprinted cotton fabric for rapid, selective and sensitive determination of carbendazim in orange juice
    (Academic Press Inc Elsevier Science, 2024) Zengin, Adem; Toptas, Yeliz; Bilici, Mustafa; Gursoy, Tulay
    Carbendazim is a type of benzimidazole fungicide commonly used to protect agricultural crops. It has high chemical stability and a long degradation half-life, which increases the potential for environmental accumulation. Herein, carbendazim-imprinted cotton fabric (MIPCF) was fabricated for the selective and sensitive detection of carbendazim in orange juice samples using spectrofluorimetry. The imprinted cotton fabrics were characterized using a variety of surface characterization techniques, and the results revealed the grafting of a polymer layer onto the cotton fabric. Furthermore, the MIPCF had a high adsorption capacity of 96.9 mg/g and an imprinting factor of 4.36. Importantly, MIPCF demonstrated satisfactory regeneration capability, enduring up to ten regeneration cycles without significantly reducing its initial adsorption capacity. The proposed method had excellent linearity with a correlation coefficient of 0.999 and a limit of detection of 1.12 mu g/L for carbendazim in orange juice samples. The proposed method exhibited acceptable recovery ranges (99.2-100 %) accompanied by lower inter-day and intra-day precisions. It is inferred that the proposed method offers a promising alternative for quantifying fungicides compared to conventional spectroscopic or chromatographic techniques.
  • Küçük Resim Yok
    Öğe
    Sustainable approach to dye adsorption: hemp-based activated carbon as an effective adsorbent
    (Taylor & Francis Ltd, 2024) Toptas, Yeliz; Yavuz, Bahar; Korkmaz, Aydan Aksogan; Onal, Yunus
    In industry, the use of dyes that threaten human health is increasing day by day. RB 19 (Reactive Blue 19, Remazol brilliant blue R), one of the most common dyes that adversely affect natural life, is the subject of this article. In this article, the waste parts of the hemp plant (root, stem and other) were evaluated for use in scientific studies. Hemp wastes were carbonised at 500 degrees C at a heating rate of 10 degrees C/min for 1 hour in the N2 atmosphere. Chemical activation was then carried out with 1:4 potassium hydroxide (KOH) at 800 degrees C under the same conditions. Activated carbon (AC) used as an adsorbent was characterised by elemental analysis (73.3% C, 0.3% H, 0.46% N, 0.02% S and 25.92% O), XRD, SEM, BET and FT-IR analysis. Activated carbon (AC) with 850 mu m size, 1858.70 m2/g surface area was obtained by chemical activation of carbonised hemp waste with KOH. SEM images showed that the activated carbon is structurally similar to a honeycomb. Kinetic parameters were analysed with six different equations (Intra Particle Diffusion, Pseudo First, Pseudo Second, Elovich, Avrami, Bangham) and adsorption mechanism with eight different equations (Henry, Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Koble-Corrigan, Flory-Huggins, Harkin-Jura). According to the calculated diffusion coefficient (19.299), it is concluded that diffusion is externally controlled. The Intra-Particle Diffusion constant (75.34) indicated that the outer adsorption layer of activated carbon was thick. When the correlation coefficients of the equations were examined according to the kinetic analysis results, the highest correlation coefficient was observed in the Pseudo-First kinetic model for all temperatures. However, it was determined that it also fits the Bangham and Avrami models. Since Bangham and Avrami models have high regression coefficients (0.96-0.99), it can be said that adsorption also fits these models. Also, the negative Gibbs Free Energy values indicate that adsorption can occur spontaneously and is thermodynamically favourable.