Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Ates, Mehmet(4)
- ALMisned, Ghada(3)
- Danabas, Durali(3)
- Guler, Omer(3)
- Tekin, H.O.(3)
- Aksu, Onder(2)
- Alkarrani, Hessa(2)
- Arslan, Zikri(2)
- Demirbilek, Deniz(2)
- Güler, Ömer(2)
- Kilic, G.(2)
- Kutlu, Banu(2)
- Mesbahi, A.(2)
- Unal, Ilkay(2)
- Abdullah Tekçe(1)
- Adigüzel, Ragip(1)
- AlMisned, Ghada(1)
- Arslanoglu-Isik, Hilal(1)
- Aydoğmuş, Ercan(1)
- Basaran, Senay(1)
- Basgoz, Oykum(1)
- Baykal, Duygu Sen(1)
- Bogatu, Coneliu(1)
- Buldurun, Kenan(1)
- Canpolat, Erdal(1)
- Cicek Cimen, Isil Canan(1)
- Cicek-Cimen, Isil Canan(1)
- Cimen, Isil Canan Cicek(1)
- Demir, Hulya(1)
- Demir, Veysel(1)
- Depci, Tolga(1)
- Ene, Antoaneta(1)
- Erguven, Gokhan Onder(1)
- Ertit Tastan, Burcu(1)
- Evin, Ertan(1)
- Fırat, Tülay(1)
- Gencel, Osman(1)
- Gholampour, Aliakbar(1)
- Gündüz, Bayram(1)
- Hacı Mehmet Aydoğdu(1)
Yayınlar
- MakaleYalnız künye2025Scopus SJRQ2Phase Stability, Structural Properties, Electronegativity, Mechanical Properties, and Neutron and Gamma-Ray Attenuation Properties of Cantor High Entropy Alloys for Advanced Nuclear Applications
Tekin, H.O.; Güler, Ömer; Özkul, İskender; AlMisned, Ghada; Baykal, Duygu Sen; Alkarrani, Hessa; Kilic, G.; Mesbahi, A.
High Entropy Alloys (HEAs) hold considerable potential for sophisticated nuclear applications, offering a vast spectrum of compositional tuning to enhance mechanical properties at high temperatures, as well as to increase resistance to radiation and corrosion. This study explores the suitability of Cantor HEAs, specifically the CoCrFeMnNi matrix enriched with elements such as Zr, Nb, Mo, Hf, Ta, and W, for nuclear applications. These elements were selected for their high atomic numbers and neutron capture cross-sections, vital for enhancing gamma-ray and neutron shielding properties. Utilizing advanced computational and theoretical methods, the elastic modulus of these alloys was theoretically estimated while their radiation attenuation capabilities were evaluated through different Monte Carlo simulation codes. CoCrFeMnNiW demonstrated the highest elastic modulus (340.9 GPa), indicating significant mechanical robustness. The addition of W resulted in superior gamma-ray attenuation, with the lowest gamma-ray transmission factors and highest neutron shielding effectiveness among the studied alloys. The calculated mass attenuation coefficients and effective removal cross-sections values demonstrate the potential of these HEAs to provide effective radiation shielding. Our results showed a clear correlation between the elastic modulus and radiation attenuation properties, suggesting that mechanical stiffness does not compromise shielding capabilities. The comprehensive analysis of thermodynamic and structural parameters, including entropy of mixing, mixing enthalpy, and Valence Electron Concentration (VEC), provided essential insights into phase stability and microstructural characteristics. It can be concluded that CoCrFeMnNiW and its related Cantor HEAs as promising materials for advancing nuclear technology, offering a new horizon for safer and more efficient nuclear systems.
AtıfScopus9OpenAlex13
İncele - MakaleAçık Erişim2025Scopus SJRQ2Advanced synthesis and comprehensive characterization of nanoparticle-reinforced epoxy-based biocomposites derived from modified palm oil
Şahal, Hakan; Aydoğmuş, Ercan; Canpolat, Erdal; Kaya, Mehmet
In this research, new biocomposites were synthesized by two-step modification of palm oil (MPO). The raw material (MPOSA) was epoxidized in the first step and obtained by reacting with 4,4-diaminodiphenyl sulfone in the second step. Silicon carbide (SiC), MPOSA, bisphenol A diglycidyl ether, and epoxy resin were used to obtain the biocomposites. After this process, necessary physical tests and chemical analyses were performed. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analyses were used to characterize the biocomposites. The research included measurements of bulk density, Shore D hardness, thermal conductivity, and thermal stability of the biocomposite. The results indicated that MPOSA reinforcement decreased the bulk density of the biocomposite in proportion to the doping level, and Shore D hardness tests revealed a decrease in hardness with the addition of MPOSA. The increase in MPOSA reinforcement also led to a reduction in the thermal conductivity coefficient. In experimental studies, the optimum reinforcement ratio was determined as 1 wt.% nano-SiC, 10 wt.% glass fiber, and 10 wt.% MPOSA. Excessive MPOSA reinforcement adversely affected the matrix structure and pore distribution of the nanocomposite due to aggregation due to increased intermolecular interaction. Thermal decomposition results showed that MPOSA reinforcement reduced the activation energy of the nanocomposite. This study successfully developed an economical, environmentally friendly, and easily processed biocomposite and contributed to the development of functional and sustainable alternatives.
AtıfScopus3WoS3OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ2Exploring thermodynamic, physical and radiative interaction properties of quinary FeNiCoCr high entropy alloys (HEAs): a multi-directional characterization study
ALMisned, Ghada; Guler, Omer; Ozkul, Iskender; Sen Baykal, Duygu; Alkarrani, Hessa; Kilic, G.; Mesbahi, A.; Tekin, H.O.
To qualify for nuclear applications, materials must meet specific criteria, including mechanical properties, high-temperature behavior, corrosion resistance, and high-temperature oxidation resistance. High Entropy Alloys (HEAs) are particularly suitable for these applications due to their unique properties. Consequently, we conducted a theoretical and simulation-based approaches to assess some critical properties including radiation shielding properties of some quinary FeNiCoCr HEAs. In this study, we focused on quinary FeNiCoCr HEAs, whose corrosion properties have been previously examined in the literature. We investigated the thermodynamic and radiation shielding properties of HEAs with sixteen different compositions. Our methodology included evaluating thermodynamic parameters such as Mixing Entropy (∆Smix) and Mixing Enthalpy (∆Hmix), as well as structural characteristics like Valence Electron Concentration (VEC) and Atomic Size Difference (δ). This allowed us to systematically deduce the phase behavior and stability of various HEAs. Through computational modeling, we assessed the radiation shielding capabilities of these alloys, particularly their effectiveness in attenuating gamma ray and fast neutrons. The results identified FeNiCoCrW as the alloy with the lowest fast neutron removal cross-section values, highlighting its potential for nuclear applications. Its high melting point and the synergistic interplay between its elemental composition and thermodynamic properties suggest broad applicability in extreme environments. Thus, FeNiCoCrW emerges as a promising HEA with multifunctional capabilities, warranting further exploration and potential integration into advanced engineering solutions.
AtıfScopus8OpenAlex10İncele - MakaleAçık Erişim2024Scopus SJRQ3Synthesis and characterization of chitosan-based pH-sensitive biofilm: An experimental design approach for release of vitamin B12
Onal, Ali; Demir, Hulya; Ince, Olcay Kaplan; Ince, Muharrem
Hydrogels because of their unique potentials, such as highwater content and hydrophilicity, are of interest for the controlled release of drug molecules. In the present study, a biofilm was produced using chitosan, a natural polymer. Characterization analyses of the synthesized biofilm were performed using Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis-differential thermal analysis, x-ray diffraction, and scanning electron microscopy-energy dispersive x-ray spectrometry. The analysis results of the film before loading were compared to the analysis made after adding vitamin B12 to the film. The release percentage of vitamin B12 was investigated by using ultraviolet-visible spectrophotometery. The FT-IR bands of vitamin B12 were in the range of 2,800-3,500 cm-1 and 1,000 cm-1-1,750 cm-1. When pH increased from 3 to 7, release of vitamin B12 from the biopolymer increased up to pH 5. While examining the release potential, parameters, such as pH, initial concentration of vitamin B12, release time, and solution volume, were optimized by using response surface methodology. It was determined that with the increase in release time and the initial concentration, pH contributed positively to the release of vitamin B12. The following conditions were determined for release of vitamin B12 from the biofilm: pH: 4.2, initial concentration of vitamin B12: 54.0 mg L-1, the release time: 117 min, and volume of solution: 2.1 mL. The analysis of variance results showed that the determination coefficients for the use of synthesized biofilm in vitamin B12 release were high and R2 =0.9704.
AtıfScopus9WoS9OpenAlex10İncele - MakaleYalnız künye2024Scopus SJRQ2Degradation Products of Rhyolitic Rocks, Adsorption Applications, Isotherm Studies
Fırat, Tülay; Sarıcı-Özdemir, Çiğdem
Heavy metals and their toxicity are a major global concern. They are one of the major environmental problems causing serious problems for living beings. In this study, the adsorption properties of a clay sample located in nature are improved by treating with different materials, and then adsorption properties are examined. It is observed that clay sample can be used in many adsorption applications, including the adsorption of heavy metals such as copper. The clay mineral used in the study was obtained from a rhyolite type rock. Rhyolite rocks, one of the degradation products of volcanic rocks, are the volcanic counterparts of granite. In this study, rhyolite rock was crushed with suitable crushers and grinders, then sieved under 200 mesh with molecular sieve and clay minerals were obtained. The clay samples (K1,K2. K8) were synthesized by subjecting clay with acid and base. Adsorption properties of clay are due to wide surface area, surface functional groups and microporosity. Adsorption of methylene blue and iodine, adsorption from aqueous solutions of copper are done with clay samples and results were compared with samples of clay have not undergone any pre-treatment. In the study, the highest adsorption capacity was determined by applying the Freundlich isotherm. In the K6 sample treated with a base, the highest adsorption capacity was calculated as 26.98 Lg−1. In contrast, the Langmuir isotherm results were calculated in the range of 10.56 to 11.86 Lg−1. This indicates that the adsorption takes place on a heterogeneous surface. The structure and surface properties of clay were examined.
AtıfScopus2WoS2OpenAlex2İncele - Yüksek Lisans TeziAçık Erişim2023Sm2(CO3)3 ve Nd2(CO3)3 çözebilecek derin ötektik sıvıların geliştirilmesi ve bu karbonatların elektrokimyasal aktivasyona karşı tepkisinin araştırılması
Hacı Mehmet Aydoğdu
Bu tez çalışmasında, nadir toprak karbonatlarının liç işlemi için uygun derin ötektik çözücüler belirlenmiştir. Viskozite ve iletkenlik ölçümleri gibi fiziksel özellikler gerçekleştirilmiştir. Deneylerde kullanılacak olan DES'lerin elektrokimyasal davranışı hakkında bilgi elde etmek için Dönüşümlü Voltametri (CV) ve Kronoamperometri (CA) teknikleri uygulanmıştır. TGA analizi, nadir toprak elementleri karbonatı içinde yaklaşık %10 hidrat gösterdi. Çıplak DES'lerin kararlı potansiyel aralıkları ve karbonatların ayrışmaya başladığı potansiyeller, mikro elektrota uygulanan CV ve CA teknikleri ile belirlenmiştir. Platin elektrot üzerinde ayrışan Nd ve Sm karbonat hidrat tozunun kimyasal bileşimini belirlemek için SEM-EDS ve XRD analizleri yapıldı. Sonuç olarak, nadir toprak elementi karbonat hidratların nadir toprak elementi oksitlerine dönüştüğü gözlemlendi. Elektrokatalitik aktivasyonun etkisini doğrulamak için, karbonatların liç etkinliği ilk olarak çıplak DES solventlerinde 55±5 oC'de 24 saat boyunca potansiyel uygulanmadan gerçekleştirildi. Daha sonra aynı deneysel liç düzeneği 6 saat boyunca elektrokatalitik aktivasyon ile çalıştırıldı. ICP-MS, çözünmüş nadir toprak elementleri için kullanıldı. Uygulanan pals teknikleri ve elektrokatalitik aktivasyon ile liç verimliliği %100'den fazla arttırılmıştır.
- Yüksek Lisans TeziAçık Erişim2023Çinko oksit nanopartiküllerin biyosentezi, karakterizasyonu ve kadmiyum giderim potansiyelinin incelenmesi
Abdullah Tekçe
Bu tez çalışmasında yeni bir biyopolimer boncuk üretildi ve sentezlenen biyopolimer boncuklar fonksiyonelleştirilerek çevre kirliliğinin önemli nedenlerinden biri olan kadmiyumun (Cd2+) sulu çözeltilerden uzaklaştırılması amacıyla kullanıldı. Bu amaçla ilk olarak reyhan bitki ekstraktı kullanılarak yeşil sentez yöntemi ile çinko oksit (ZnO) nanopartikülleri (ZnO-NP) elde edildi. Üretilen nanopartiküller ultraviyole görünür bölge (UV-GB) spektroskopisi, Fourier dönüşümlü infrared (FTIR) spektroskopisi, X ışını kırınımı (XRD) ve taramalı elektron mikroskobu-enerji dağılım spektroskopisi (SEM-EDS) ile karakterize edildi. Daha sonra nanopartiküller sodyum aljinat ile kaplanarak yeni bir biyopolimer boncuk (ZnO-NP@ALJ) geliştirildi ve böylece ZnO nanopartiküllerin ve sodyum aljinatın performansı ve kararlılığı arttırıldı. Biyosentezlenen boncuklar ayrıca etilendiamin tetraasetik asit (EDTA) ve tannik asit ile fonksiyonelleştirildi. Bu şekilde elde edilen üç farklı boncuğun adsorpsiyon yetenekleri karşılaştırıldı. Adsorpsiyon parametrelerinin optimizasyonu için yüzey yanıt metodu (YYM) ile kombine edilmiş merkezi kompozit tasarımı (MKT) yöntemi kullanıldı. Bu yöntem ile adsorpsiyon prosesine etki eden pH, sıcaklık ve adsorban miktarı gibi bağımsız değişkenlerin optimum seviyeleri belirlendi. Varyans analizleri yapıldı ve elde edilen regresyon katsayıların yüksek olduğu tespit edildi. Fisher ve t-testleriyle, kullanılan metotların validasyonları gerçekleştirildi. ZnO katkılı polimerik kompozit malzemenin Cd2+ iyonlarının gideriminde adsorpsiyon doğasını aydınlatmak için izoterm denge çalışmalarından Langmuir, Temkin ve Freundlich modelleri kullanıldı. Kinetik verileri değerlendirmede yalancı birinci dereceden, yalancı ikinci dereceden ve parçacık içi difüzyon modelleri kullanıldı. Cd2+ iyonlarının gideriminde en uygun modelin yalancı ikinci dereceden model olduğu tespit edildi. Termodinamik çalışmaları sonucunda ise adsorpsiyonun kendiliğinden gerçekleştiği sonucuna varıldı. Üretilen üç kompozit malzeme için optimum şartlar pH için 5, sıcaklık için 32.5 °C ve adsorban miktarı için 5 mg olarak belirlendi. Bu optimum koşullarda (ZnO-NP@ALJ)-TA'nın 35.9 mg g-1 ile en yüksek adsorpsiyon kapasitesine sahip malzeme olduğu bulundu.
- MakaleAçık Erişim2023Scopus SJRQ3Structural, physical, and radiation absorption properties of a significant nuclear power plant component: A comparison between REX-734 and 316L SS austenitic stainless steels
Say, Yakup; Güler, Ömer; Kavaz, Esra; ALMisned, Ghada; Ene, Antoaneta; Tekin, Huseyin Ozan
Austenitic stainless steels (SSs) are commonly used as in-core and surrounding structural materials in today’s industrial BWR and PWR systems. Such adaptable steels have also been the primary materials studied and used in several advanced nuclear reactor technologies, such as fast breeding and magnetic fusion reactors. In this study, some critical material properties, such as structural, physical, and radiation-shielding properties of REX-734 and 316L SS, were experimentally evaluated and compared to those of a number of other alloys. In addition to homogeneous element distribution, both alloys exhibit strong crystal orientation. The REX-734 alloy has a tensile strength of 1,259 MPa, whereas the 316L SS alloy has a tensile strength of 495 MPa. Moreover, nitrogen in the REX-734 alloy formed ultra-hard nitrides with Cr, Nb, and Si and precipitated into the structure and increased the strength. According to our findings, the mass attenuation coefficient values of the 316L SS sample were slightly higher than those of the REX-734 sample at all energies. It can be concluded that the REX-734 sample, with its exceptional strength qualities and excellent radiation attenuation capabilities, may be a viable nuclear power plant material for future investigations.
AtıfScopus7İncele - MakaleAçık Erişim2023Scopus SJRQ1Physical-Mechanical and Electrical Resistivity Properties of Cementitious Mortars Containing Fe3O4-MWCNTs Nanocomposite
Selen, Veyis; Guler, Omer; Nodehi, Mehrab; Sarı, Ahmet; Yaras, Ali; Gencel, Osman; Gholampour, Aliakbar; Ozbakkaloglu, Togay
Recent growth in materials science and engineering technologies has pushed the construction industry to engage in new applications, such as the manufacturing of smart and electrically conductive products. Such novel uses of conductive construction materials would potentially allow their use in conjunction with various fields, such as those referred to as “Industry 4.0.” The following study uses iron oxide (Fe3O4)-multi-walled carbon nanotubes (MWCNTs) nanocomposites synthesized by chemical vapor deposition (CVD) and incorporated into the cementitious mortars as a substitute for sand at 1, 2, and 3% ratios to enhance the electrical conductivity. Results reveal that the electrical resistivity of cementitious composites decreases (due to the increase in electrical conductivity) from 208.3 to 61.6 Ω·m with both the Fe3O4-MWCNTs nanocomposites ratio and the increasing voltage. The lowest compressive strengths at 7 and 28 days are 12.6 and 17.4 MPa for specimens with 3% Fe3O4-MWCNTs and meet the standards that comply with most applications. On the other hand, the highest porosity was reached at 26.8% with a Fe3O4-MWCNTs rate of 3%. This increase in porosity caused a decrease in both the dry unit weight and ultrasonic pulse velocity (from 5156 to 4361 m/s). Further, it is found that the incorporation of Fe3O4-MWCNT nanocomposites can have a negative effect on the hardening process of mortars, leading to localized air cavities and an inhomogeneous development of cementing products. Nonetheless, the improvement of the electrical conductivity of the samples without significantly compromising their physico-mechanical properties will allow their use in various fields, such as deicing applications with low-voltage electric current.
AtıfScopus7OpenAlex7İncele - Yüksek Lisans TeziAçık Erişim2022Hibrit biyonanokompozit malzemelerin sentezlenmesi ve sulu çözeltilerden neodimyum gideriminde kullanımının modellenmesi
Hakan Andiçi
Bu tez çalışmasında aljinat ve kitosan kaplı manyetik demir oksit (Fe3O4) nanopartiküllerin (aljinat-Fe3O4, kitosan-Fe3O4), biyosentez tekniği ile sentezlendi. Sentezlenen aljinat- Fe3O4 ve kitosan-Fe3O4 hibrit biyonanokompozitlere sabit bir kolon içerisinde Nd3+'nın adsorpsiyonu ve desorpsiyonu yanıt yüzey metodolojisi (YYM) ile kombine edilmiş bir merkezi kompozit tasarım yaklaşımı (MKT) kullanılarak ve kontrollü desorpsiyonu incelendi. Aljinat-Fe3O4 ve kitosan-Fe3O4 nanokompozitlerin karakterizasyonu UV-GB, FT-IR, TGA-DTA, XRD ve SEM-EDS kullanılarak gerçekleştirildi. Sentezlenen ve karakterize edilen söz konusu biyokompozite malzemelere, Nd3+ iyonlarının adsorpsiyonu, çözelti pH'ı, çözeltinin kolondan akış hızı ve başlangıç Nd3+ iyonları konsantrasyonunun bir fonksiyonu olarak incelendi. Nd3+'nın hem aljinat-Fe3O4 hem de kitosan-Fe3O4 hibrit biyo-nanokompozit üzerine adsorpsiyonu sabit yataklı bir kolon sistemi kullanılarak optimum koşullar pH 5.4, çözeltinin kolondan akış hızı 4.0 mL dk-1 ve Nd3+ iyonları başlangıç konsantrasyonunun 120 mg L-1 olarak belirlendi. Aljinat-Fe3O4 ve kitosan-Fe3O4 biyo-nanokompozitlerin maksimum adsorpsiyon kapasitesi ve verimliliği sırasıyla 125.01 mg g-1, %99.8; 99.99 mg g-1, % 99.8 olarak hesaplandı. Deneysel parametrelerin optimizasyonu MKT yaklaşımı ile gerçekleştirildi ve önerilen kuadratik modelden hem aljinat-Fe3O4 hem de kitosan-Fe3O4 Nd3+ iyonlarının adsorpsiyonu için birer matematiksel model elde edilerek sunuldu. Varyans analizi sonuçları sentezlenen her iki kompozit malzemenin Nd3+ iyonlarının gideriminde kullanılmasındaki belirleme katsayılarının yüksek olduğunu gösterdi.
- MakaleAçık Erişim2022Scopus SJRQ1Synthesis and structural, electrical, optical, and gamma-ray attenuation properties of ZnO-multi-walled carbon nanotubes (MWCNT) composite separately incorporated with CdO, TiO2, and Fe2O3
Basgoz, Oykum; Guler, Omer; Evin, Ertan; Yavuz, Cagdas; ALMisned, Ghada; Issa, Shams A.M.; Zakaly, Hesham M.H.; Tekin, H.O.
In this study, Fe2O3, TiO2, and CdO semiconductor metal oxides were separately incorporated into the ZnO-MWCNT composite at different weight percentages. Accordingly, several experimental analyses on electrical, optical, and radiation shielding characteristics of coupled semiconductor metal oxides nanocomposites were performed to determine their monotonic impact on the investigated material properties. Moreover, gamma-ray shielding properties of these novel materials were determined using MCNPX general-purpose Monte Carlo code. At 5% oxide addition, the maximum electrical conductivity was found in all groups for all temperatures. Moreover, 5% oxide reinforcement resulted in the maximum reflection characteristics in all groups. Among the CdO doped materials, the CZnOCd5 sample exhibits the highest electrical conductivity behaviour at room and high temperatures. The Eg value calculated for the CZnOCd5 sample was 3.284 eV. The CZnOCd2.5 and CZnOCd5 samples had the greatest Eg values when compared to the pure sample and the samples from other groups. The CZnOCd5 sample has the highest reflectance value in the CZnOCd group's reflectance graph. On the other hand, the maximum gamma-ray attenuation properties were reported for CZnOCd5 sample. Among the analysed samples, the CZnOCd5 sample's characteristics provide a preliminary motivation for a more comprehensive analysis of this material and assessment of potential radiation protection applications.
AtıfScopus29OpenAlex28İncele - MakaleYalnız künye2020Scopus SJRQ2Assessment of Oxidative Stress on Artemia salina and Daphnia magna After Exposure to Zn and ZnO Nanoparticles
Ates, Mehmet; Danabas, Durali; Ertit Tastan, Burcu; Unal, Ilkay; Cicek Cimen, Isil Canan; Aksu, Onder; Kutlu, Banu; Arslan, Zikri
In this study, the effect of zinc nanoparticles (Zn NPs) and zinc oxide nanoparticles (ZnO NPs) on Artemia salina and Daphnia magna, the primary consumer organisms were investigated. In this sense, investigation of trophic transfer and ecological sustainability potentials among living things, such as fish and crustaceans that are at the top of the food chain were also aimed. Zn NPs in the size of 40–60 nm and 80–100 nm and ZnO NPs (10–30 nm) were administered to A. salina and D. manga (respectively in total 105000 and 14000 individuals) in seven groups (Control, 0.2, 1, 5, 10, 25 ve 50 ppm) with three repetitions for a period of 72 h. Intensive and possible misuse of nanoscale materials is one of the biggest threats to the environment and all living things worldwide. Therefore, the control mechanisms for the use of NPs need to be established.
AtıfScopus29WoS19OpenAlex32
İncele - MakaleYalnız künye2020Scopus SJRQ2An Evaluation Research About Effects of Characterized Cadmium Selenide (CdSe) and Lead Selenide (PbSe) Quantum Dots on Brine Shrimp (Artemia salina)
Ates, Mehmet; Tastan, Burcu Ertit; Danabas, Durali; Cicek-Cimen, Isil Canan; Aksu, Onder; Kutlu, Banu; Unal, Ilkay; Arslan, Zikri
Quantum dots (QDs), such as cadmium selenide (CdSe) and lead selenide (PbSe) exhibit excellent optical, magnetic and chemical properties due to their extremely size (ca. 1–10 nm) and are attractive semiconductor nanomaterials for optical studies and energy storage. In this study, aqueous synthesis of CdSe and PbSe QDs in a size range of 2–10 nm was described. Synthesized QDs were characterized using SEM and TEM, DLS, zeta potential, FTIR, EDX and XRD. Highest accumulation (72.5 ± 5.8 mg L−1) of PbSe QDs occurred at 10 ppm suspensions. In general accumulation increased up to 48 h exposure then fluctuate tended to decline. For CdSe QDs, accumulation tended to decrease for 72 h exposure except that for 5 ppm groups. For the elimination period, in general, the elimination levels of PbSe and CdSe QDs from exposed individuals decreased (p < 0.05) even it has some fluctuate.
AtıfScopus6WoS4OpenAlex5İncele - MakaleYalnız künye2020Scopus SJRQ1Comparative effects of Cu (60–80 nm) and CuO (40 nm) nanoparticles in Artemia salina: Accumulation, elimination and oxidative stress
Cimen, Isil Canan Cicek; Danabas, Durali; Ates, Mehmet
In this study, nanotoxicity tests were made by exposure of Artemia salina to copper (Cu 60–80 nm) and copper oxide (CuO 40 nm) nanoparticles (NPs) at different concentrations (0.2, 1, 5, 10, 25, and 50 mg/l) during some exposure duration. Characterization of Cu and CuO NPs were performed using Transmission Electron Microscope (TEM), Dynamic Light Scattering (DLS), Zeta Potential, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transformation Infrared (FT-IR) analyzes. In organisms, the accumulation and elimination rates of NPs was determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) analysis and the oxidative stress effects on A. salina were determined by Glutathione (GSH) and Thiobarbituric acid reactive substances (TBARS) analysis methods. Both NPs were found to differ in accumulation and elimination rates at each application time and in parallel with the increase in concentration. In each group, it was determined that ion release increased with application time. The results showed that the accumulation rates in Cu NPs had a tendency to increase at 48 h and to decrease at 72 h in concentrations of 0, 2 and 1 mg/l, respectively. And in the all other concentrations have been seen an increasing trend within the time. In the CuO NPs (40 nm), accumulation rates were a decrease trend at 48th hour and an increase trend at 72nd hour except 10 mg/l concentration. In the 10 mg/l group was an increase trend with the application period. Cu NP, TBARS value increased with increasing concentrations and the highest increase was observed at 24 h of 5 ppm group. The groups showed a tendency to increase-decrease-increase-decrease in TBARS levels in terms of elapsed time (24th, 48th, 72nd hour and elimination) (5 ppm and 10 ppm groups tended to decrease in TBARS level at 72nd hour). TBARS increased with increasing concentration ratios in CuO NPs (40 nm).
AtıfScopus32WoS27OpenAlex34İncele - MakaleYalnız künye2019Scopus SJRQ4CHARACTERIZATION OF ERBIUM OXIDE NANOPARTICLES
Ates, Mehmet; Kar, Bulent; Bogatu, Coneliu
Considering the advantages of nanoscale materials such as being lighter, more robust, programmable materials, less material usage, less energy requirement during production phase, and no longer producing materials, it is important to produce nanomaterials and determine their properties. Therefore, the characterization of nanomaterials has become one of the pillars of material science. An important aspect of nanoscale material science is the method of characterization of materials that we use or study to learn more about them. In recent years, great importance has been given to rare earth materials with nanostructures. One of the rare earth elements is Erbium and it is one of the newly discovered materials that is used in high technology. Erbium oxide (Er2O3) nanoparticles (NPs) are used in electronic devices. It is used in capacitors, metal oxide semiconductor transistors, and as dopants for optical fiber and laser materials. In this study, Erbium based Er2O3 NPs were characterized. The characterization of Er2O3 was realized using X-ray diffraction (XRD), scanning electron microscopy (SEM), the energy dispersive X-ray (EDX), and Fourier transform infrared spectroscopy (FT-IR). The number of specific peaks and their position fit very well with those from standard XRD spectrum and revealed pure Er2O3 nano oxide. SEM analysis of these particles showed their spherical shapes that are in great extent uniform distributed with nano sizes ranged between 40-60 nm.
- MakaleYalnız künye2018Scopus SJRQ2The determination of present and possible environmental risks in solid waste dumping site, Tunceli, Turkey
Yildirim, Nuran Cikcikoglu; Demirbilek, Deniz; Erguven, Gokhan Onder; Kayar, Rahime; Basaran, Senay; Tulpar, Dilan
Leachate was a major cause of high risk classification. This landfill was set as one with highest possible risk classification due to high vulnerability of private water wells to contamination from leachate flows. The aim of this study is to determine the present and possible environmental risks of the leachate spreading from solid waste dumping site in Tunceli and offer solutions for those determined environmental risks. For this purpose, the characteristics of the leachate were monitored at two station points detected in the solid waste dumping site for 7 months. The characteristics of the leachate were found for pH between 7.9 and 8.7. Oxidation reduction potential (ORP) occurred between − 143 and − 48 mV while conductivity was between 2.8 and 2.6 mS. Total solid matter (TSM) and suspended solid matter (SSM) were between 1000 and 7000 mg/l, 0.2–22.5 mg/l, respectively, while total volatile solids (TVS) occurred between 300 and 1800 mg/l for the two stations. Alkalinity was approximately between 290 and 5210 mg/l, while biological oxygen demand (BOD5) and chemical oxygen demand (COD) results were 15–606 mg/l and 60–1160 mg/l, respectively, for two stations in all sampling time. In both stations, orthophosphate, ammonium nitrogen, nitrate, sulfate, and chloride analyses stayed between 3.04 and 921.1 mg/l; 0.29–619.36 mg/l; 8.94–135.04 mg/l; 125.9–1360.9 mg/l and 99.9–1249.9 mg/l, respectively, in 6 months. As a result of the characterization studies obtained from the leachate, it was found that the amounts of water entering into the waste mass and the retention period of the water in the mass were very effective in the temporal character change of the leachate. According to the Discharge Standards for Solid Waste Assessment and Disposal Facilities and Discharge to Waste Water Infrastructure Facilities of waste management regulation, the results were found to be risky. Consequently, the site in question needs to be urgently rehabilitated when considering the environmental risks of the leachate spreading from the site.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2016Scopus SJRQ3Identification of chrysotile in local soil at Beypinari village (Sivas-Turkey) regarding mine and health issue
Önal, Yunus; Depci, Tolga; Önal, Ayten; Önal, Ali; Üner, Tijen
Asbestos is dangerous for health and is forbidden to use in Turkey, but villagers who live in rural eastern part still use it especially for their home for insulation purposes and even as a substitute for baby powder. Therefore, geological and chemical properties of this type of soil, which is near the settlement, should be characterized and identified from the point of view of health. Beypinari asbestos deposits are located at Beypinari village, about 90 km southeast of Sivas, Turkey within Central Anatolian Ophiolites. Therefore, in the present study, the existence of chrysotile in Beypinari asbestos deposit were characterized and identified by mineralogical analysis and by major, trace, REE analysis. The results show that the samples contain different amount of calcite mineral, the main mineral being chrysotile.
- MakaleYalnız künye2014Scopus SJRQ3Study of Structure and Spectral Characteristics of the Zinc(II) and Copper(II) Complexes With 5,5-Dimethyl-2-(2-(3-nitrophenyl) hydrazono)cyclohexane-1,3-dione and Their Effects on Optical Properties and the Developing of the Energy Band Gap and Investigation of Antibacterial Activity
Turan, Nevin; Gündüz, Bayram; Körkoca, Hanifi; Adigüzel, Ragip; Çolak, Naki; Buldurun, Kenan
A new chelating ligand, 5,5-dimethyl-2-(2-(3-nitrophenyl)hydrazono)cyclohexane-1,3-dione (L), and four transition metal complexes were synthesized. The ligand and its complexes were characterized by IR, H-1 and C-13-NMR spectra, elemental analyses, magnetic susceptibility, mass spectra, UV-Vis. and thermogravimetry-differential thermal analysis (TGA-DTA). The metal complexes showed different geometric structures. Antibacterial tests of the ligand and complexes were also done. The Zn(II) complexes showed antibacterial activity against Staphylococcus aureus ATCC-25923 at middle level. The optical properties of the ligand and its complexes were extensively investigated by optical measurements. The average transmittance value of the ligand was the highest value, while the average transmittance value of the [CuL2(NO3)(2)]center dot 6H(2)O complex was the lowest value. The optical band gap of the ligand, [(Zn)(2)L(OH)(4)]center dot 2DMF, [ZnL(NO3)(2)(H2O)(2)]center dot 5H(2)O, [CuL2(OAc)]center dot OAc center dot 3.5H(2)O and [CuL2(NO3)(2)]center dot 6H(2)O complexes were calculated and 3.121 eV, 2.180 eV, 1.551 eV, 2.489 eV and 1.556 eV values were found, respectively. The complexes decreased the optical band gap of the ligand. The optical band gap value of the [ZnL(NO3)(2)(H2O)(2)]center dot 5H(2)O complex is the lowest value. The optical band gap value of the ligand is the highest value. The complexes decrease the angle of incidence of the ligand, while complexes increase the angle of refraction of the ligand. The electric susceptibility of the ligand decreases with its complexes.
AtıfWoS28İncele - MakaleAçık Erişim2013Scopus SJRQ2Characterization and pollution potential assessment of Tunceli, Turkey municipal solid waste open dumping site leachates
Demirbilek, Deniz; Önal, Ayten Oztufekci; Demir, Veysel; Uslu, Gulsad; Arslanoglu-Isik, Hilal
Environmental monitoring of leachate quality from an open municipal solid waste dumping site in Tunceli, Turkey was studied in this research. The most commonly examined pollution parameters were determined on a seasonal basis. The annual average 5-day biological oxygen demand (BOD5) and chemical oxygen demand (COD) values of station points were measured as 70 and 425 mg/L, respectively, and also the average BOD5/COD ratio (a measure of biodegradability) was calculated as 0.20. The low ratio of biodegradability and slightly alkaline pH values in the leachate samples indicated that the site was characterized by methanogenic conditions. The mean ammonium-nitrogen (NH4 (+)-N) and corresponding phosphate (orthophosphate) values were assayed as 70 and 11 mg/L, respectively. The average solids content in the leachates was measured as 4,681 mg/L (total solids) and 144 mg/L (suspended solids). Very low concentrations of iron, manganese, copper, and zinc in the leachate samples were found and the concentration of cadmium was measured below detection limits. Excessive amount of nutrients and high organic and inorganic pollutant content in the leachates pose serious pollution potential to the environment. Since no drainage system or bio treatment exists in this open dumping site, high permeability of natural soil at the site and in the surrounding area and very fractured and crackled rocks under natural soil are indicators of high groundwater pollution potential in this site.
AtıfWoS23OpenAlex21İncele