Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Duran, Celal(9)
- Ozdes, Duygu(9)
- Bektas, Hakan(4)
- Serencam, Huseyin(4)
- Soylak, Mustafa(3)
- Akcay, Hakki Turker(1)
- Bahadır, Zekeriyya(1)
- Bora, Pınar(1)
- Bulut, V. Numan(1)
- Bulut, Volkan Numan(1)
- Elvan, Hamide(1)
- Gundogdu, Ali(1)
- Gümrükçüoglu, Nurhan(1)
- Kaya, Yusuf(1)
- Mentese, Emre(1)
- Polat, Alper(1)
- Sahin, Deniz(1)
- Tufekci, Mehmet(1)
- Tumay, Sureyya O.(1)
- Özkan Avit(1)
- Şükrü Özşahin, Talat(1)
Yayınlar
- MakaleYalnız künye2026Scopus SJRQ3Analytical Solution of Discontinuous Contact Problem in Functionally Graded Layer and Homogeneous Layer
Kaya, Yusuf; Polat, Alper; Şükrü Özşahin, Talat; Bora, Pınar
In the study, the problem of discontinuous contact in two layers, one of which is functionally graded is solved using the theory of elasticity. In this problem functionally graded (FG) layer resting on homogeneous layer and loaded with two different rigid flat blocks. In addition, homogeneous layer is resting on a rigid plane. Frictions on all surfaces are neglected. The heights of the FG layer and the homogeneous layer are h1 and h2, respectively. When solving the problem, displacement and stress equations are substituted in the boundary conditions. Then the problem is demained to singular integral equations. Wherein unknown functions are the contact stresses under the two rigid flat blocks and the slope of the separation. These singular integral equations are solved numerically using the Gauss- Chebyshev integration formulas. The analyzes were performed for different inhomogeneity parameter (βh1), shear modulus ratio (μ2/μ-h1). distance between the rigid blocks ((a3-a2)/h1) and density parameter (γh1). Consequently, the stress distributions and starting and ending points of the separation area between the FG layer and homogeneous layer are determined for several dimensionless quantities.
- MakaleYayıncıda açık erişim2023Scopus SJRQ3A facile and sensitive coprecipitation method coupled with flame atomic absorption spectrometry for quantification of Cu(II) ions in complex matrices
Ozdes, Duygu; Duran, Celal; Bektas, Hakan; Mentese, Emre
In the present investigation, the application of an organic coprecipitant, 2-[5,6-dichloro-2-(2-bromobenzyl)-1H-benzimidazole-1-yl]acetohydrazide (DIBBA), for separation and preconcentration of Cu(II) ions in fruit and water samples through a new carrier element free coprecipitation (CEFC) method was researched for the first time. Flame atomic absorption spectrometer (FAAS) was used for the analyses of Cu(II) ions. The main effective experimental factors such as solution pH, DIBBA quantity, waiting time, centrifuge speed and duration and volume of sample on the recovery efficiency of Cu(II) ions were explored in detail. Under the optimized conditions the preconcentration factor (PF), relative standard deviation (RSD), and limits of detection (LOD) was achieved as 50, 3.4 % and 0.44 µg L-1, respectively. No interference effects were detected by virtue of the presence of various foreign ions. Satisfactory recoveries (in the range of 94.4 to 103.0 %) in the environmental sample matrix were acquired. After being validated the recommended selective, low cost, simple and rapid CEFC method by spike/recovery tests, it was properly implemented for the low levels detection of Cu(II) ions in sour cherry, mulberry, apple, and peach as fruit samples and stream and sea water samples without any significant matrix effects.
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İncele - MakaleYalnız künye2023Scopus SJRQ2Application of Magnetic Fe3O4 Alnus glutinosa Sawdust Biochar/SiO2/CTAB as a New Sorbent for Magnetic Solid Phase Extraction of Heavy Metals from Fruit and Waters Samples
Duran, Celal; Ozdes, Duygu
The coating of magnetic Fe3O4 Alnus glutinosa sawdust biochar with SiO2 and further functionalising by cetyltrimethyl ammonium bromide (CTAB), a cationic surfactant, was described for the first time in the current paper. The magnetic Fe3O4 Alnus glutinosa sawdust biochar/SiO2/CTAB(MAGBC/SiO2/CTAB) was implemented to separate and preconcentrate the Cu2+, Cd2+, and Pb2+ions efficiently in waters and a number of fruit samples by solid-phase extraction (SPE) method. Adsorbent characterisation was realised by fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Fundamental factors affecting the extraction yield of the analyte ions including solution pH, adsorbent amount, sample volume and desorption contact time were fully researched and optimised as 8.0, 0.25 g, 500 mL and 60 min, respectively, and the eluent was specified as 5.0 mL of 0.1 M of HCl solution. The adsorption equilibrium eventuated after 15 min of contact time and it was noticed that the chemisorption mechanism was dominant upon the analyte ions adsorption. The limits of detection (LOD) were calculated as 0.24, 0.62 and 1.55 µg L−1 and the limits of quantitation (LOQ) were determined as 0.81, 2.08, and 5.17 µg L−1 for Cu2+, Cd2+, and Pb2+ ions, respectively. The relative recoveries (RR%) were in the ranges of 93.3–103.4%, 92.5–102.8%, and 91.8–101.9% for Cu2+, Cd2+, and Pb2+ ions, respectively, while the relative standard deviations (RSD%) were obtained lower than 4.0% (n = 10) by applying the method at optimised conditions. The maximum adsorption capacities of MAGBC/SiO2/CTAB were obtained as 123.7, 80.0 and 118.5 mg g−1for Cu2+, Cd2+, and Pb2+ions, respectively. Consequently, the developed new, simple, rapid, sensitive, and economical SPE method based on MAGBC/SiO2/CTAB was successfully implemented to waters and some of the fruit samples to determine the Cu2+, Cd2+, and Pb2+ions simultaneously.
AtıfScopus15WoS17OpenAlex17İncele - Yüksek Lisans TeziAçık Erişim2022Bazı uyumlu kesirli kısmi diferansiyel denklemlerin nümerik çözümleri
Özkan Avit
Bu tez,beş ana bölümden oluşmaktadır. Birinci bölümde kesirli türevin ve uyumlu kesirli türevin oluşumu ve gelişimi hakkında bilgi verilmektedir. İkinci bölümde gerekli tanım ve teoremler yazılmıştır. Üçüncü bölümde kullanılan yöntemlerden bahsedilmiştir. Dördüncü bölümde ise uyumlu kesirli mertebeden Kuramoto-Sivashinsky (UKMKS) denklemleri, uyumlu kesirli mertebeden Whitham-Broer-Kaup (UKMWBK) denklemleri, uyumlu zaman-kesirli mertebeden Jaulent Miodek (UZKMJM) sistemi, uyumlu kesirli mertebeden Cahn-Allen (UKMCA) denklemi için uyumlu q-homotopi analiz dönüşüm yöntemi (Uq-HADY), uyumlu kesirli Elzaki ayrıştırma yöntemi (UKEAY), uyumlu homotopi pertürbasyon Elzaki dönüşüm yöntemi (UHPEDM) olarak adlandırılan üç farklı yöntem kullanılarak yeni sayısal çözümler araştırılmıştır. Bu yöntemlerin etkili ve güvenilir olduğunu doğrulamak için sayısal simülasyonlar yapılmıştır. Elde edilen çözümler ile analitik çözümler arasındaki karşılaştırmalar yapılmıştır. Son bölümde ise yeni önerilen her üç yeni tekniğin de doğrusal olmayan uyumlu kesirli problemleri çözmek için basit, güçlü ve etkili olduğu vurgulanmaktadır.
- MakaleYalnız künye2021Scopus SJRQ2Preparation of melon peel biochar/CoFe2O4 as a new adsorbent for the separation and preconcentration of Cu(II), Cd(II), and Pb(II) ions by solid-phase extraction in water and vegetable samples
Ozdes, Duygu; Duran, Celal
The present research describes the successful preparation of melon peel biochar modified with CoFe2O4 (MPBC/CoFe2O4) followed by its usage as a new sorbent to separate, preconcentrate, and determine the toxic heavy metal ions by magnetic solid-phase extraction. The metal ion desorption was performed by 0.1 M HCl solution with a volume of 5.0 mL. Flame atomic absorption spectrometry (FAAS) was utilized for detection of the analyte levels. SEM–EDX, TEM, XRD, and FTIR techniques were carried out to illuminate the structure of MPBC/CoFe2O4. The fundamental variables affecting the adsorption and elution efficiencies of the analyte ions including solution pH, MPBC/CoFe2O4 amount, type and concentration of eluent, adsorption and desorption equilibrium time, and sample volume were optimized. The detection limits were calculated as 0.41, 1.82, and 3.16 µg L−1 for Cu2+, Cd2+, and Pb2+ ions, respectively, with the relative standard deviation of lower than 4.2%. There were no substantial interference effects on the analyte ion recovery due to the presence of foreign ions at high levels. Five minutes of contact time was adequate to attain the adsorption equilibrium. The adsorption capacity of MPBC/CoFe2O4 was obtained as 106.4, 65.4, and 188.7 mg g−1 for Cu2+, Cd2+, and Pb2+ ions, respectively, by utilizing Langmuir isotherm model. The pseudo-second order model is favorable to identify the adsorption kinetics. The method was validated by spike/recovery test, and then, it was successfully implemented to determine the aforementioned analyte levels in sea and stream water, pepper, black cabbage, eggplant, and tomato samples.
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İncele - MakaleAçık Erişim2015Scopus SJRQ3Selective separation, preconcentration and determination of Pd(II) ions in environmental samples by coprecipitation with a 1,2,4-triazole derivative
Ozdes, Duygu; Duran, Celal; Serencam, Huseyin; Sahin, Deniz; Gundogdu, Ali; Soylak, Mustafa
A simple, sensitive, facile and low cost methodology, combined with flame atomic absorption spectrometry (FAAS), was employed to evaluate the selective separation and preconcentration of Pd(II) ions in environmental samples by using a triazole derivative as an organic coprecipitating agent without a carrier element. The developed method was systematically investigated in different set of experimental parameters that influence the quantitative recovery of Pd(II) ions. The accuracy of the method was tested by analyzing certified reference material and spike tests. The developed coprecipitation procedure has been applied to road dust, anodic slime, industrial electronic waste materials and water samples to determine their Pd(II) levels.
AtıfScopus12WoS12İncele - MakaleAçık Erişim2015Scopus SJRQ2Simultaneous separation and preconcentration of Cd(II), Co(II), and Ni(II) ions in environmental samples by carrier element-free coprecipitation method prior to their flame atomic absorption spectrometric determination
Duran, Celal; Ozdes, Duygu; Akcay, Hakki Turker; Serencam, Huseyin; Tufekci, Mehmet
ABSTRACT: In the present study, Cd(II), Co(II), and Ni(II) ions were separated and preconcentrated via carrier element-free coprecipitation (CEFC) method by using an organic coprecipitating agent, 1,2-bis-(2-tosyl ethoxy) benzene (BTEB), prior to their flame atomic absorption spectrometric (FAAS) detections. The experimental conditions were optimized in terms of pH of the aqueous solution, BTEB amount, standing time, centrifugation rate and time, and sample volume. Under the optimum experimental conditions, the detection limits for Cd(II), Co(II), and Ni(II) ions were found to be 0.13, 0.67, and 0.46 μg L−1, respectively, and the relative standard deviations for the analyte ions were found to be lower than 4.0%. The accuracy of the method was tested by analyzing certified reference material and spike tests. The method was applied to determine the levels of Cd(II), Co(II), and Ni(II) ions in sea and stream water, macaroni, red lentil, and cracked wheat samples.
AtıfScopus17WoS16OpenAlex16İncele - MakaleYalnız künye2014Scopus SJRQ1Separation and preconcentration of lead, chromium and copper by using with the combination coprecipitation-flame atomic absorption spectrometric determination
Bahadır, Zekeriyya; Bulut, Volkan Numan; Ozdes, Duygu; Duran, Celal; Bektas, Hakan; Soylak, Mustafa
A coprecipitation method was developed for the quantitative separation and preconcentration of Pb(II), Cr(III) and Cu(II) ions. Analytes were coprecipitated using a triazole derivative (2-{4-[2-(1H-indol-3-yl)ethyl]-3-(4-chlorobenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl}. N-aryl methylidene acetohydrazid). The analytes were analyzed by flame atomic absorption spectrometry. The parameters such as sample pH, amount of reagent, sample volume, matrix effects etc. were investigated. The enrichment factor for the analyzed metal ions was obtained as 50. The relative standard deviations (RSD) were in the range of 2.8-4.1%. The accuracy of the proposed procedure was checked by the analysis of the CRM-C-Sandy Soil C. The method was successfully applied to real samples.
AtıfScopus73WoS66OpenAlex65İncele - MakaleYalnız künye2014Scopus SJRQ1Simultaneous separation and preconcentration of Ni(II) and Cu(II) ions by coprecipitation without any carrier element in some food and water samples
Duran, Celal; Tumay, Sureyya O.; Ozdes, Duygu; Serencam, Huseyin; Bektas, Hakan
A simple and highly sensitive separation and preconcentration procedure, which has minimal impact on the environment, has been developed. The procedure is based on the carrier element-free coprecipitation of Ni(II) and Cu(II) ions by using 2-{4-[2-(1H-Indol-3-yl)ethyl]-3-(4-chlorobenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl}-N′-(pyrrol-2-ylmethyliden)acetohydrazide (ICOTPA), as an organic coprecipitant. The levels of analyte ions were determined by flame atomic absorption spectrometry. The detection limits for Ni(II) and Cu(II) ions were found to be 0.27 and 0.58 μg L-1, respectively, and the relative standard deviations for the analyte ions were lower than 4.0%. Spike tests and certified reference material analyses were performed to validate the method. The method was successfully applied for the determination of Ni(II) and Cu(II) ions levels in sea and stream water as liquid samples and red lentil and rice as solid samples.
AtıfScopus26WoS23OpenAlex25İncele - MakaleYalnız künye2013Scopus SJRQ3Application of carrier element free coprecipitation (CEFC) method for determination of Co(II), Cu(II) and Ni(II) ions in food and water samples
Serencam, Huseyin; Duran, Celal; Ozdes, Duygu; Bektas, Hakan
A simple and highly sensitive separation and preconcentration procedure, which has minimal impact on the environment, has been developed. The procedure is based on the carrier element free coprecipitation (CEFC) of Co(II), Cu(II), and Ni(II) ions by using 2-{4-[2-(1H-indol-3-yl)ethyl]-3-(4-methylbenzyl)-5-oxo- 4,5-dihydro-1H-1,2,4-triazol- 1-yl}-N'-(pyridin-2-yl methylidene)acetohydrazide (IMOTPA), as an organic coprecipitant. The levels of analyte ions were determined by flame atomic absorption spectrometry (FAAS). The detection limits for Co(II), Cu(II) and Ni(II) ions were found to be 0.40, 0.16 and 0.17 μg L-1, respectively, and the relative standard deviations for the analyte ions were lower than 3.0%. Spike tests and certified reference material analyses were performed to validate the method. The method was successfully applied for the determination of Co(II), Cu(II) and Ni(II) ions levels in sea and stream water as liquid samples and red pepper, black pepper, and peppermint as solid samples.
AtıfScopus10WoS10İncele - MakaleAçık Erişim2013Scopus SJRQ2Development of a new solid phase extraction procedure for selective separation and enrichment of Au(III) ions in environmental samples
Elvan, Hamide; Ozdes, Duygu; Duran, Celal; Bulut, V. Numan; Gümrükçüoglu, Nurhan; Soylak, Mustafa
A highly sensitive, selective and low cost solid phase extraction (SPE) procedure was developed for separation and enrichment of Au(III) ions in environmental samples prior to its flame atomic absorption spectrometric detection. Au(III)-2-pyridin-5-(4-tolyl)-1,3,4-oxadiazole (PYTOX) complex was adsorbed quantitatively on Amberlite XAD-4 resin in 0.5 mol L-1 HNO3 condition and the elution was carried out with 7.5 mL of 1.0 mol L-1 HCl in acetone. Some analytical parameters, affect the recoveries of Au(III) ions, such as HNO3 concentration of sample solution, amount of PYTOX, type, concentration and volume of eluent, sample volume and concomitants were examined. Adopting optimized experimental conditions, the limit of detection for Au(III) ions was 1.03 μg L-1 with preconcentration factor of 50 and a relative standard deviation (RSD) of 3.7%. The determination of Au(III) ions in anodic slime, gold ore, soil and sea and stream waters was performed after checking the accuracy of the method by addition-recovery tests.
AtıfScopus7WoS7OpenAlex6İncele