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The worthy green heterogeneous Fenton degradation process for removal of E102 in foodstuffs and industrial waste-waters using Cypress arizonica leaves based magnetic nanocomposite (CA-Fe3O4-MNc)
Get PDFA new, green magnetic nanocomposite (MNc) was synthesized based on framework of Cypress arizonica (CA) leaves and then used as Fenton catalyst for removal of tartrazine (E102) in foodstuffs and industrial wastewaters. Characterization of the synthesized magnetic nanocomposite (CA-Fe 3 O 4 -MNc) was performed with IR, EDX, FESEM, XRD and pH pzc analyses. The average particle size and pH pzc of the CA-Fe 3 O 4 -MNc were determined to be 24.36 nm and 6.8, respectively. CA-Fe 3 O 4 -MNc was composed of C (15.08 %), Fe (51.86 %), O (31.80 %) and Ca (1.26 %) elements. The parameters effecting heterogeneous Fenton dye removal process including pH, catalyst amount, reaction time, H 2 O 2 and initial dye concentrations were investigated to achieve the best removal efficiency for E102. Under optimal conditions, the matrix effect was investigated, the reusability of CA-Fe 3 O 4 -MNc was tested, degradation products and mechanism were elucidated, and green analytical procedure index (GAPI) and analytical eco-scale (AES) of the proposed Fenton degradation process were evaluated. E102 removal values were obtained between 93 and 99 % in the applications of some foodstuffs, water samples and artificial model dye solutions. Proposed heterogeneous Fenton removal process with using CA-Fe 3 O 4 -MNc catalyst exhibited quantitative removal efficiency for E102. E102 concentrations between 5 and 50 mg/L were removed successfully. It was observed that the synthesized CA-Fe 3 O 4 -MNc material could be used at least 5 times to obtain quantitative removal values. The percent removal efficiency value decreased to 93 after five uses. Defined GAPI parameters and calculated AES scores indicated that the proposed CA-Fe 3 O 4 -MNc based heterogeneous Fenton degradation process could be considered that a valuable green removal method
Improving device performance of sputtered CZTSe based solar cells by Manganese doping
Get PDFDespite many efforts, Cu2ZnSnSe4 (CZTSe) based solar cells have remained relatively low efficiency compared to other thin film-based devices. One of the prevalent strategies used to improve cell performance in CZTSe is cation substitution. In this contribution, the effects of substituting Mn for Zn on CZTSe solar cell performance were systematically examined. Samples with various Mn content were grown by a two-stage method involving high temperature annealing of precursor layers comprising Cu, Zn, Sn, Mn and Se. All of the samples were found to have Cu-poor and (Zn + Mn)-rich or nearly stoichometric compositions. They crystalized in kesterite phase irrespective of the Mn content as confirmed by X-ray diffraction (XRD), Raman and X-ray photoelectron spectroscopy (XPS) measurements. The highest efficiency solar cell (5.56%) was obtained employing the 5% Mn doped CZTSe absorber. This film was found to have improved microstructure and reduced defect density. This is the first report on over 5% efficient kesterite thin film solar cell fabricated on a Cu2Mn0.05Zn0.95SnSe4 absorber layer.Scientific and Technological Research Council of Tuerkiye [120F029]This study is financially supported by the Scientific and Technological Research Council of Tuerkiye with the project number of 120F029
Türkiye'de Phillips Eğrisinin Geçerliliği: Çoklu Yapısal Kırılmalara Dayalı Ampirik Bulgular
Get PDFBu çalışmada Türkiye'de kısa ve uzun vadede Phillips eğrisinin geçerliliğini, 1960 ile 2022 yılları arasındaki enflasyon ve işsizlik verilerini içeren bir veri seti ile çoklu yapısal kırılmaları dikkate alan Carrion-i-Silvestre vd. (2009) çoklu yapısal kırılmalı birim kök testi, Maki (2012) çoklu yapısal kırılmalı eşbütünleşme testi ve Newey-West HAC Tahmincisi kullanılarak incelenmektedir. Bu çalışma, değişkenler arasındaki ilişkinin sapmasız bir şekilde elde edilebilmesi için hem birim kök analizinde hem de eş bütünleşme analizinde yapısal kırılmaları dikkate alan az sayıdaki çalışma arasında yer alması, aynı zamanda diğer çalışmalardan farklı olarak 1960’ları kapsayacak şekilde en geniş ve en güncel veri setiyle değişkenler arasındaki ilişkiyi ampirik olarak incelemesi bakımından literatüre önemli bir katkı sağlamayı amaçlamaktadır. Bulgular, Türkiye'de uzun vadede Phillips Eğrisinin geçerli olmadığını, ancak kısa vadede önemli bir ters ilişki olduğunu (enflasyon ile işsizlik arasında trade-off) göstermektedir. Kısa dönem sonuçları işsizlik oranındaki 1 birimlik artışın TÜFE’yi 0,49 düşürdüğünü göstermektedir. Bu sonuçlar, Monetarist ve Yeni Keynesyen görüşlerle uyumlu olup, politika yapıcılar için önemli ipuçları sunmaktadır. Bu doğrultuda, çalışmada Yeni Keynesyen ve Monetarist ekollerinin savunduğu görüşler ekseninde politika yapıcılara bir dizi para ve maliye politikası önerileri sunulmaktadır
Synthesis, characterization, and phosphorus adsorption of Mg/Fe-modified biochar from cotton stalk pretreated with Coriolus versicolor
Get PDFIn recent years, the research potential in utilizing biochars as adsorbents in adsorption processes has grown due to their eco-friendly and economical nature. However, biochar often possesses a negative surface charge that limits its affinity for binding anions. Nitric acid washing and pretreatment with Coriolus versicolor can break down the lignocellulosic structure in cotton stalk waste, facilitating the subsequent impregnation of Mg and Fe metal oxides. These pretreatment steps can lead to the production of diverse and functionalized biochars with higher adsorption capacities. In this study, cotton stalk waste was first washed with diluted nitric acid and then subjected to biological pretreatment by incubation with C. versicolor, followed by impregnation with Mg and Fe to obtain CV-CS/Fe and CV-CS/Mg biochars. The results showed that the applied pretreatments altered the physicochemical properties and significantly increased the phosphorus adsorption capacity. The adsorption capacities of CV-CS/Fe and CV-CS/Mg biochars were found to be 277.88 and 507.01 mg g(-1), respectively. The results indicate that the incorporation of multiple metal oxide impregnates enhances P adsorption. Furthermore, in the kinetic study, pseudo-first-order and pseudo-second-order models provided a well fit, determining chemical adsorption as the main adsorption mechanism for phosphorus adsorption. The biochars demonstrated compatibility with Langmuir-Freundlich models. Overall, the findings suggest the possibility of synthesizing biochars with improved adsorptive properties through pretreatment, and these engineered biochars hold promising potential as effective adsorbents in the field.This study was derived by the Master of Science thesis of Coriolus versicolor added modified biochar production and phosphorus recovery by adsorption from Nide omer Halisdemir University
Recovery of phenolic compounds from peach pomace using conventional solvent extraction and different emerging techniques
Get PDFThe study compared high-pressure, microwave, ultrasonic, and traditional extraction techniques. The following extraction conditions were implemented: microwave-assisted extraction (MAE) at 900 W power for durations of 30, 60, and 90 s; ultrasonic-assisted extraction (UAE) at 100% amplitude for periods of 5, 10, and 15 min; and high-pressure processing (HPP) at pressures of 400 and 500 MPa for durations of 1, 5, and 10 min. The highest yield in terms of total phenolic content (PC) was obtained in UAE with a value of 45.13 +/- 1.09 mg gallic acid equivalent (GAE)/100 g fresh weight (FW). The highest PC content was determined using HPP-500 MPa for 10 min, resulting in 40 mg GAE/100 g, and MAE for 90 s, yielding 34.40 mg GAE/100 g FW. The highest value of antioxidant activity (AA) was obtained by UAE in 51.9% +/- 0.71%. The PCs were identified through the utilization of Fourier transform infrared (FTIR) spectroscopy and high-performance liquid chromatography (HPLC). Utilizing multivariate analysis, the construction of chemometric models were executed to predict AA or total PC of the extracts, leveraging the information from IR spectra. The FTIR spectrum revealed bands associated with apigenin, and the application of HPP resulted in concentrations of 5.41 +/- 0.25 mg/100 g FW for apigenin and 1.30 +/- 0.15 mg/100 g FW for protocatechuic acid. Furthermore, HPLC analysis detected the presence of protocatechuic acid, caffeic acid, p-coumaric acid, and apigenin in both green extraction methods and the classical method. Apigenin emerged as the predominant phenolic compound in peach extracts. The highest concentrations of apigenin, p-coumaric acid, and protocatechuic acid were observed under HPP treatment, measuring 5.41 +/- 0.25, 0.21 +/- 0.04, and 1.30 +/- 0.15 mg/kg FW, respectively
Determination of fire intensity after forest fire by remote sensing: marmaris case study
Get PDF3rd International Conference on Research of Agricultural and Food Technologies, I-CRAFT 2023 -- 4 October 2023 through 6 October 2023 -- Adana -- 196444Forest fires in Turkiye are a frequently encountered natural disaster, especially in recent years. After a fire, identifying the plant species to be used in the area and determining the intensity of the fire in the region are important for assessing the area's capacity for natural regeneration. In this process, geographic information systems and remote sensing methods and techniques are commonly used tools for assessing burned areas and fire intensities following forest fires. In this study, one of Turkiye's devastating fires, the Marmaris fire, which began on June 21, 2022, is examined. Landsat satellite images, geometrically and radiometrically corrected, were utilized to determine the intensity of the Marmaris fire. As part of the method, the NBR (Normalized Burn Ratio), dNBR (Difference Normalized Burn Ratio), NDVI (Normalized Difference Vegetation Index), and dNDVI (Difference Normalized Difference Vegetation Index) indices were used for burned area detection. As a result of the study, information about the burned areas, fire intensities, and the regenerative capabilities of post-fire vegetation growth has been obtained. Furthermore, suitable pioneer plant species, considering the fire intensity, have been suggested for the restoration of burned landscape areas after the fire. This study is expected to serve as a guide for relevant public institutions and organizations, particularly the General Directorates of Forestry, enabling them to respond most effectively after fires and implement reforestation efforts considering the usage areas and growth capabilities of needle-leaved and broad-leaved plants. © The Authors, published by EDP Sciences
Isolated Cricoid Cartilage Fracture After Blunt Thoracocervical Trauma: A Case Report
Get PDFAlthough cricoid cartilage fracture is rare because of the firm and stable structure of the cricoid cartilage, it can cause fatal complications. Prompt diagnosis and rapid airway safety are incredibly vital. A 24-year-old male patient was admitted to the emergency department due to blunt trauma to the thoracocervical region. The computed tomography taken after the first interventions detected a displaced fracture of the cricoid cartilage. In light of the patient's clinical findings, the patient was treated conservatively and non-surgically with close follow-up of the airway safety
Graphene integrated CZTS thin film solar cells
Get PDFFen Bilimleri Enstitüsü, Fizik Ana Bilim DalıTez kapsamında, saçtırma sistemi kullanılarak Mo, Ni ve Cu folyolar üzerine Altlık/ZnS/CuSn/Cu yapısı üretilmiş ve Hızlı Tavlama Sistemi (RTP) ile Mo, Ni ve Cu folyolar için sırasıyla 550 °C, 425 °C ve 425 °C optimize edilen sıcaklıklarda sülfürlenerek CZTS filmler elde edilmiştir. Esnek-folyo/CZTS/CdS/i-ZnO/ITO/Al yapısı kullanılarak üretilen güneş hücrelerinde en yüksek hücre verimi %3.26 ile Mo-folyo/CZTS yapısından elde edilmiştir (Hücre-I). Ayrıca, CVD yöntemiyle Mo, Ni ve Cu folyolar üzerinde farklı katman sayılarında katkısız, N2-katkılı (NKGr) ve B2H6-katkılı (Diboran katkılı) (DKGr) grafen filmler sentezlenmiş ve yapılan karakterizasyonlar sonucunda Mo ve Cu folyolar üzerinde tek (TKGr) ve birkaç katmanlı (BKGr), Ni folyolar üzerinde ise birkaç ve çok katmanlı (ÇKGr) grafen filmlerin başarılı bir şekilde sentezlendiği belirlenmiştir. Tez kapsamında, yapılan grafen entegrasyonu ile Mo-folyo/BKGr/CZTS/CdS/i-ZnO/ITO/Al ve Ni-folyo/ÇKGr/CZTS/CdS/i-ZnO/ITO/Al yapısından sırasıyla %3.72 ve %2.3 (Hücre-II), Mo-folyo/BKGr/CZTS/CdS/i-ZnO/80nmITO/BKGr/Al yapısından %7.8 (Hücre-III), Mo-folyo/DKGr/CZTS/CdS/i-ZnO/80nmITO/BKGr/Al yapısından %8.57 (Hücre-IV) ve Mo-folyo/DKGr/CZTS/CdS/i-ZnO/80nmITO/NKGr/Al yapısından %9.0 hücre verimi elde edilmiştir.In this thesis, a Substrate/ZnS/CuSn/Cu structure was fabricated on Mo, Ni, and Cu foils using a sputtering system, and CZTS films were obtained by sulfurizing these foils at optimized temperatures of 550 °C, 425 °C, and 425 °C, respectively, using a Rapid Thermal Processing (RTP) system. In solar cells produced using the flexible-foil/CZTS/CdS/i-ZnO/ITO/Al structure, the highest cell efficiency of 3.26% was achieved with the Mo-foil/CZTS structure (Cell-I). Additionally, pristine, N2-doped (NKGr), and B2H6-doped (DKGr) graphene were synthesized on Mo, Ni, and Cu foils using the CVD method. Characterizations revealed that single-layer (TKGr) and few-layer (BKGr) graphene films were successfully synthesized on Mo and Cu foils, while BKGr and multi-layer (ÇKGr) graphene films were successfully synthesized on Ni foils. With the integration of graphene in the thesis, cell efficiencies of 3.72% and 2.3% were obtained from Mo-foil/BKGr/CZTS/CdS/i-ZnO/ITO/Al and Ni-foil/ÇKGr/CZTS/CdS/i-ZnO/ITO/Al structures, respectively (Cell-II). Furthermore, efficiencies of 7.8% were achieved from Mo-foil/BKGr/CZTS/CdS/i-ZnO/80nmITO/BKGr/Al structure (Cell-III), 8.57% from Mo-foil/DKGr/CZTS/CdS/i-ZnO/80nmITO/BKGr/Al structure (Cell-IV), and 9.0% from Mo-foil/DKGr/CZTS/CdS/i-ZnO/80nmITO/NKGr/Al structure
Neural network and thermodynamic optimization of magnetized hybrid nanofluid dissipative radiative convective flow with energy activation
Get PDFThis article, motivated by hybrid magnetic coating manufacturing developments, utilizes a neural network-based computational program to study the dynamics of hybrid magnetic nanofluids with entropy generation. A new physico-chemo-mathematical model has been presented to simulate the hybrid magnetic nano-coating flow along a stretching surface to a porous medium with viscous heating. A Rosseland flux model is used for radiation heat transfer and Darcy's model for the isotropic porous medium. The stretching sheet is porous, and wall suction or injection are possible. A robust neural network has been deployed to optimize the physical parameters controlling the transport characteristics of hybrid nanofluids. Specifically, two hybrid nanoparticle combinations are addressed, namely graphite oxide (GO)-molybdenum disulfide (MoS2) and copper (Cu)-silicon dioxide (SiO2), both with engine oil as the base fluid. The dimensional boundary layer model is transformed via suitable scaling variables from a partial differential system into a dimensionless non-linear coupled ordinary differential system. The transformed boundary value problem is solved numerically with the BVP4C subroutine in the symbolic software MATLAB, which achieves exceptional accuracy. Validation with previous simpler studies is conducted and a good correlation is obtained. The neural network optimization analysis incorporates Bayesian regularization as the training algorithm. The Bejan entropy generation minimization (EGM) analysis shows that with increasing radiation parameter R-d, both entropy generation rate and Bejan number are increased. Furthermore, an elevation in Brinkman number Br leads to an upsurge in entropy generation rate and a downtrend in the Bejan number. The numerical solution of the boundary value problem reveals that with an increment in nanoparticle solid volume fraction phi(2), magnetic parameter M, inverse permeability parameter epsilon, surface injection parameter (s0) and Prandtl number Pr, there is a strong enhancement in temperature magnitude and thermal boundary layer thickness. With greater nanoparticle solid volume fraction phi(2), magnetic parameter M, inverse permeability parameter epsilon, suction parameter s and a reduction in thermal buoyancy parameter lambda, strong flow deceleration is induced, and momentum boundary layer thickness is increased. The skin friction coefficient is substantially boosted with lower values of magnetic parameter M, inverse permeability parameter epsilon, suction parameter s and higher values of thermal buoyancy parameter lambda. There is a significant decrement also computed in Nusselt number with a greater radiation parameter R-d. The simulations provide a good benchmark for future extensions that may consider non-Newtonian behavior.University of Dhaka; University Grants Commission of Bangladesh Grant [2022-2023]We are grateful to University of Dhaka and University Grants Commission of Bangladesh Grant 2022-2023 for providing the financial support for this work
Examination of the relationship between psychological resilience, nomophobia and psychological distress levels of university students
Get PDFEğitim Bilimleri Enstitüsü, Eğitim Bilimleri Ana Bilim Dalı, Rehberlik ve Psikolojik Danışmanlık Bilim DalıBu çalışmada üniversite öğrencilerinin psikolojik sağlamlık, nomofobi ve psikolojik uyumsuzluk düzeyleri arasındaki ilişkinin incelenmesi amaçlanmıştır. Araştırma grubunu 2022-2023 eğitim öğretim yılında Niğde Ömer Halisdemir Üniversitesinde çeşitli fakültelerde öğrenim gören 18-30 yaş arası 823 öğrenci oluşturmaktadır. Araştırma verileri; Kısa Psikolojik Sağlamlık Ölçeği, Nomofobi Ölçeği, Depresyon Anksiyete Stres (DASS-21) Ölçeği ve Kişisel Bilgi Formu ile toplanmıştır. Bu araştırmada, üniversite öğrencilerinin psikolojik sağlamlık, nomofobi ve psikolojik uyumsuzluk düzeyleri arasındaki ilişkiyi incelemek için araştırmada ilişkisel model kullanılmıştır. Verilerin analizinde t testi, tek yönlü varyans analizi, basit doğrusal ve hiyerarşik regresyon analizi kullanılmıştır. Elde edilen sonuçlar incelendiğinde; nomofobinin cinsiyete, yaşa ve akıllı telefonu kullanım saatine göre anlamlı farklılık gösterdiği, öğrenim görülen fakülteye ve akıllı telefona sahip olma yılına göre anlamlı farklılık göstermediği sonucu elde edilmiştir. Psikolojik sağlamlık ve psikolojik uyumsuzluk değişkenlerinin ise cinsiyete göre anlamlı farklılık gösterdiği tespit edilmiştir. Psikolojik sağlamlık nomofobinin tüm alt boyutlarını (bilgiye erişememe, bağlantıyı kaybetme, iletişim kuramama, rahatlıktan feragat etme) anlamlı ve negatif yönde, psikolojik sağlamlık psikolojik uyumsuzluğun tüm alt boyutlarını (depresyon, anksiyete, stres) anlamlı ve negatif yönde, nomofobinin tüm alt boyutları ise psikolojik uyumsuzluğun tüm alt boyutlarını anlamlı ve pozitif yönde yordamaktadır. Araştırma sonucunda; psikolojik sağlamlık ile psikolojik uyumsuzluk arasındaki ilişkide nomofobinin kısmi aracılık rolü olduğu sonucuna ulaşılmıştır. Elde edilen bulgular mevcut alanyazına dayanarak tartışılmış ve öneriler sunulmuştur. Anahtar Kelimeler: Üniversite Öğrencileri, Psikolojik Sağlamlık, Nomofobi, Psikolojik UyumsuzlukIn this study, it was aimed to examine the relationship between psychological resilience, nomophobia and psychological distress levels of university students. The research group consisted of 823 students between the ages of 18-30 studying in various faculties at Niğde Ömer Halisdemir University during the 2022-2023 academic year. Research data were collected using the; Brief Psychological Resilience Scale, Nomophobia Scale, Depression Anxiety Stress (DASS-21) Scale and Personal Information Form. In this study, a relational model was used to examine the relationship between psychological resilience, nomophobia and psychological distress among university students. For data analysis, a t-test, one-way analysis of variance, and simple linear and hierarchical regression analyses were used. When the results obtained were analyzed; it was concluded that nomophobia showed a significant difference according to gender, age and hours of smartphone use, but did not show a significant difference according to faculty and year of owning a smartphone. Psychological resilience and psychological distress variables were found to differ significantly according to gender. Psychological resilience predicts all sub-dimensions of nomophobia (not being able to access information, losing connection, not being able to communicate, sacrificing comfort) significantly and negatively, psychological resilience predicts all sub-dimensions of psychological distress (depression, anxiety, stress) significantly and negatively, and all sub-dimensions of nomophobia predict all sub-dimensions of psychological distress significantly and positively. As a result of the study, it was concluded that nomophobia has a partial mediating role in the relationship between psychological resilience and psychological distress. The findings were discussed based on the existing literature and recommendations were presented. Keywords: University Students, Psychological Resilience, Nomophobia, Psychological Distres