Sürdürülebilir Kalkınma Amaçları

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• MakaleYalnız künye2024Scopus SJRQ1/r/munzur/1696
  Lanthanum-based magnetic biopolymers for brilliant green removal from aqueous solutions

  Karaaslan Ayhan, Nagihan

  In this study, lanthanum (La)-based magnetic biopolymers were synthesized, and the first adsorption study was conducted on the removal of brilliant green dye from aqueous water with these biopolymers. For the adsorption study, adsorption parameters were investigated and the ideal adsorption conditions determined for the removal of brilliant green dye from aqueous solutions are pH 11, t 60 min, m 10 mg, C0 25 mg/L, T 298 K. It was determined that the adsorption process was compatible with the single-layer Langmuir isotherm, and maximum adsorption capacity obtained according to the Langmuir isotherm was calculated as 256.41 mg/g. The adsorption process was found to be in accordance with the pseudo-second-order, and the adsorption process was explained by intra-particle diffusion. According to studies of adsorption thermodynamics, it has been established that the nature of the adsorption reaction is spontaneous, and this process is endothermic and has increasing randomness. Moreover, the reusability of magnetic lanthanum/alginate (La/Alg) biopolymers was investigated, and it was determined that the biopolymers could be used successfully. In summary, brilliant green dye has been successfully removed with simple, low-cost, environmentally friendly, and easily obtained magnetic La/Alg biopolymers. It can be stated that even low amounts of these biopolymers can be effective in the treatment of highly concentrated dye wastewaters.

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  AtıfScopus1·OpenAlex1

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• MakaleYalnız künye2023Scopus SJRQ1/r/munzur/2951
  Improving dielectric properties, electrical conductivity, and thermal properties of biodegradable polymer composites prepared with lanthanum

  Torgut, Gulben; Ayhan, Nagihan Karaaslan; Acikses, Aslisah

  The precipitation method was adapted to synthesize the poly(ε-caprolactone-copolymer- ethylene oxide) (ε-CL-co-EO) composite with the salt of lanthanum (La), a rare earth element. This salt was incorporated into the polymer of different weight percentages to study how it affects the thermal and dielectric properties of the polymer. The resulting products were characterized by Fourier Transform Infrared Spectroscopy, X-ray diffractometry (XRD), Scanning electron microscopy (SEM) and thermogravimetric analysis. XRD and SEM data show that the polymer mixes homogeneously with the metal salt. Thermal degradation data show that the thermal stability of composites synthesized with La is lower than that of pure polymer. The dielectric properties and A.C conductivity measurements of the composites were investigated by using impedance analyzer in the frequency range (100 Hz to 20 kHz) at room temperature. The electrical property results of (ε-CL-co-EO)/La composites displayed that dielectric constant (έ), dielectric loss (ε"), tan delta (tan δ) and A.C electrical conductivity (σac) increase with increasing La content. The largest conductivity of (ε-CL-co-EO)/La composite filled with 20 wt% La was 8.80 × 10−8 S/cm, which was 162% times pure (ε-CL-co-EO). In addition, impedance (IZI) of composites was evaluated from the dielectric data. This procedure is eco-friendly and easy to handle, which provides a promising route to polymer composites in the application of the conductivity field.

  AtıfScopus6·WoS6·OpenAlex7

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• MakaleYalnız künye2023Scopus SJRQ2/r/munzur/2104
  Antibacterial activity of novel synthesized chitosan-graft-poly(N-tertiary butylacrylamide)/neodymium composites for biomedical application

  Yazdıç, Ferit Can; Karaman, Altuğ; Torğut, Gülben; Ayhan, Nagihan Karaaslan

  In this present study, composites of chitosan-graft-poly(N-tertiary butylacrylamide) (CH-graft-poly(N‑tert‑BAAm)) copolymer, with Neodymium (Nd), an important rare earth element, were prepared by precipitation technique. Nd was successfully incorporated into the polymer of different weight percentages (0.5%, 1%, and 2%) without any degradation. The effect of neodymium additives on the structural, morphological, and antibacterial activities against gram-positive bacteria and gram-negative bacteria of the polymer was analyzed using various instrument techniques. X-ray diffraction (XRD) results together with Fourier Transform Infrared (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) studies confirmed the morphology of Nd-doped CH-graft-poly(N‑tert‑BAAm) composites without any other impurities. The antibacterial effect of Nd was studied by adding it to the copolymer in a weight ratio of 0.5%–2%. The antibacterial effect of neodymium concentration on four different strains of bacteria was investigated: Escherichia coli (ATCC 25922) (E. coli), Pseudomonas aeruginosa (DSM 50071) (P. aeruginosa), Bacillus subtilis (DSM 1971) (B. subtilis), and Staphylococcus aureus subsp. aureus (ATCC 25923) (S. aureus). The antibacterial activities of the obtained composites were determined using the Agar Well Diffusion Assay Method. Experimental results show that Nd binds well to CH-graft-poly(N‑tert‑BAAm). Activity against E. coli, P. aeruginosa, B. subtilis, and S. aureus subsp. aureus creates a potential for pharmaceutical and biomedical applications.

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  AtıfScopus8·WoS7·OpenAlex8

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• MakaleYalnız künye2023Scopus SJRQ1/r/munzur/1811
  Adsorption potential of neodymium/alginate beads for removal of Congo red and Brilliant blue G from aqueous solution

  Seker, S.; Karaaslan Ayhan, N.

  In this study, neodymium/alginate (Nd/Alg) beads were prepared to removal of Congo Red (CR) and Brilliant Blue G (BBG) dyes from aqueous solution and the adsorption potentials of these dyes were investigated. For this, Nd/Alg beads prepared using crosslinking were characterized by FTIR, SEM–EDS and TGA. For the adsorption of CR and BBG dyes, the effects of various parameters including the amount of Nd in adsorbent (bead), pH, contact time, adsorbent amount, initial dye concentration and temperature were investigated. The optimum conditions for the effective removal of CR and BBG dyes were determined as Nd amount in bead: 3%, pH: 7, contact time: 60 min, bead amount: 15 mg, initial dye concentration: 25 mg/L and temperature 298 K. Adsorption isotherm studies (Langmuir and Freundlich isotherms) and kinetic studies (pseudo-first-order and pseudo-second-order) were carried out under optimum conditions. The adsorption data were found to completely follow Langmuir model for CR and BBG dyes. The maximum adsorption capacities were found to be 46.03 mg/g for CR and 25.25 mg/g for BBG under optimum conditions. The adsorption kinetic data of both dyes were found to be compatible with pseudo-first-order and adsorption processes were explained by intraparticle diffusion. According to thermodynamic studies, nature of adsorption reaction was spontaneous, exothermic and increasing randomness for both dyes. As a result, it can be concluded that Nd/Alg beads obtained with a natural polymer have low cost and high efficiency and even small amounts of these beads have high potential for treatment of high concentration dye wastewater.

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  AtıfScopus10·WoS8·OpenAlex10

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• MakaleAçık Erişim2023Scopus SJRQ3/r/munzur/1622
  The biosorption of Co(II) by Homalothecium sericeum from aqueous solutions under batch conditions: response surface methodology optimization and Daphnia magna bioassay

  Tanyol, Mehtap; Korkmaz, Volkan; Yildirim, Numan; Erguven, Gokhan Onder; Ayhan, Nagihan Karaaslan; Alatas, Mevlut

  In the present work, Homalothecium sericeum biomass was used for removal of Co(II) from aqueous solution. The effects of process parameters (contact time, biosorbent amount, and initial Co(II) con-centration) on the response (Co(II) % removal) were investigated using a batch adsorption system optimized with response surface methodology/central composite design method. Under optimized conditions the maximum Co(II) removal efficiency achieved is 94.07% at an initial Co(II) concentration of 2.05 mg/L, a H. sericeum amount of 0.34 g/50 mL, and a process time of 36.09 min. In this study, the toxicity of the medium after biosorption carried out under optimized conditions was also tested with Daphnia magna bioassay. When mortality results with D. magna were evaluated, although a removal efficiency of 94.07% was obtained after biosorption, this was not sufficient to reduce mortality of D. magna.

  AtıfScopus1·WoS2

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• MakaleAçık Erişim2022Scopus SJRQ1/r/munzur/2699
  Evaluation of Iron and Zinc Contents of Some Fish Species

  Karaaslan Ayhan, Nagihan; Yaman, Mehmet

  In this study, Fe and Zn contents in the muscle of different fish species (Engraulis encrasicolus, Trachurus trachurus, Mullus barbatus, Mugil cephalus, Pomatomus saltatrix, Dicentrarchus labrax, Scomber scombrus, Sparus aurata) were determined using flame atomic absorption spectrometry (FAAS). The highest Fe and Zn contents among studied fish species were found in Engraulis encrasicolus (7.13 ± 0.19 mg/kg) and Sparus aurata (11.00 ± 0.28 mg/kg). The lowest Fe and Zn contents were determined in Dicentrarchus labrax (3.12 ± 0.09 mg/kg) and Pomatomus saltatrix (5.50 ± 0.05 mg/kg). Moreover, the results were evaluated considering the estimated daily intakes (EDI) of these elements for adults. The estimated daily intakes were varied from 0.0101 to 0.0231 mg/kg bw/day for Fe and 0.0178 to 0.0357 mg/kg bw/day for Zn in fish species. In addition, the hazard quotient (HQ) and the hazard index (HI) values were calculated for risk assessment, and it was determined that these values were below 1 for fish species.

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  AtıfScopus10·WoS8·OpenAlex9

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• MakaleYalnız künye2022Scopus SJRQ3/r/munzur/2387
  Characterization of the antioxidant activity, total phenolic content, enzyme inhibition, and anticancer properties of Achillea millefolium L. (yarrow)

  Karaaslan Ayhan, Nagihan; Karaaslan Tunc, Merve Goksin; Noma, Samir Abbas Ali; Kurucay, Ali; Ates, Burhan

  The antioxidant activity, total phenolic content, enzyme inhibition, anticancer properties of Achillea millefolium L. (yarrow), which is generally consumed by humans as herbal tea, were investigated. Yarrow extracts were prepared with different extraction techniques and solvents and the optimum conditions were determined. When the antioxidant activity and total phenolic content results were evaluated, the best yield was obtained with ultrasound-assisted extraction for all solvents. Moreover, the yields from highest to lowest were methanol, water, and acetonitrile. The enzyme inhibition and anticancer of Achillea millefolium L. extracts using methanol were evaluated. The IC50 values for the inhibition of xanthine oxidase and acetylcholinesterase were 4.974 ± 0.54 and 21.891 ± 1.118 µg/mL, respectively. The extract concentration was determined to be 23.85 μg/mL for 50% reduction in growth inhibitory activity cell viability (IC50) against breast cancer (MCF-7).

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  AtıfScopus7·OpenAlex9

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• MakaleAçık Erişim2021Scopus SJRQ3/r/munzur/3338
  Determination of fatty acids in Allium tuncelianum (Tunceli garlic) by gas chromatography with flame ionization detection (GC–FID)

  Ugur, Yilmaz; Karaaslan-Ayhan, Nagihan; Icen, M. Sina; Bicim, Tulin; Erdogan, Selim; Yaman, Mehmet

  Garlic has an important place in daily nutrition. It is consumed by people because of its antimicrobial, antibacterial, and antioxidant properties, and it is also known to be good for many diseases. Along with these properties of garlic, its fatty acid content is also important. The goal of this study is to determine the fatty acids in Allium tuncelianum (Tunceli garlic), which grows naturally in Tunceli, Turkey, by gas chromatography with flame ionization detection (GC–FID). Fifteen of 37 fatty acids studied were detected in Allium tuncelianum, and the primary fatty acids in the sample extracts were determined to be the polyunsaturated fatty acid (PUFA) linoleic acid (C18:2n6c, 41.595%) and the monounsaturated fatty acid (MUFA) oleic acid (C18:1n9c, 33.302%). Small quantities of saturated fatty acids (SAFAs) were also present, including palmitic acid (C16:0, 11.739%), henoicosanoic acid (C21:0, 6.946%), and stearic acid (C18:0, 2.362%).

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  AtıfScopus12·WoS8·OpenAlex11

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• MakaleAçık Erişim2021Scopus SJRQ3/r/munzur/3310
  Determination of anthocyanins and anthocyanidins in the wild grape (Vitis sylvestris Gmelin) by high-performance liquid chromatography-diode array detection (HPLC-DAD)

  Karaaslan-Ayhan, Nagihan; Yaman, Mehmet

  The determination of anthocyanins and anthocyanidins in wild grapes (Vitis sylvestris Gmelin) from Tunceli-Turkey are reported together with the influence of the extraction conditions on the results. Representative sets of anthocyanins (delphinidin-3-o-glucoside, cyanidin-3-o-glucoside, pelargonidin-3-o-glucoside, malvidin-3-o-glucoside) and anthocyanidins (delphinidin, cyanidin, pelargonidin, malvidin) were simultaneously determined by high performance liquid chromatography with diode array detection (HPLC-DAD). The extraction conditions including the solvent type, extraction time and liquid:solid ratio (v:w) were optimized. The anthocyanin and anthocyanidin contents changed significantly depending on the extraction conditions. Malvidin-3-o-glucoside was identified to be the primary compound.

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  AtıfScopus10·WoS8·OpenAlex11

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• MakaleYayıncıda açık erişim2021Scopus SJRQ2/r/munzur/2948
  Investigation of antioxidant properties of chamomile consumed as herbal tea

  Karaaslan Ayhan, Nagihan

  Common chamomile is consumed as herbal tea due to its antioxidant properties and biological activities in daily life. In this study, antioxidant activities and total phenolic contents of white and yellow chamomiles were investigated in terms of extraction methods and solvent types. In all extraction methods used for extraction of both chamomiles, the best antioxidant activity and total phenolic results were obtained with water extracts. Also, the best yield was found with sonication-assisted stirring for both chamomile extracts obtained using three extraction solvents. DPPH and ABTS radical scavenging activities obtained by sonication-assisted stirring for water extracts were 10.886 ± 0.244 mg TEAC/g and 8.702 ± 0.567 mg TEAC/g for white chamomile, and 11.709 ± 0.693 mg TEAC/g and 11.139 ± 0.514 mg TEAC/g for yellow chamomile. The total phenolic contents were determined as 3.863 ± 0.325 mg GAE/g for white chamomile and 5.225 ± 0.417 mg GAE/g for yellow chamomile. Novelty impact statement: In this study, the antioxidant properties of white and yellow chamomile were examined in detail in terms of different extraction methods and solvent types. Sonication-assisted stirring and water were determined to be the best extraction method and solvent for both chamomiles. According to the results, it can be stated that chamomile has higher antioxidant properties than white chamomile under the best extraction conditions.

  AtıfScopus9·WoS9·OpenAlex8

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