Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(114)
- Kaya, Yunus(48)
- Şahin, Engin(48)
- İspirli, Hümeyra(47)
- Özen, Soner(38)
- Şenay, Volkan(37)
- Pat, Suat(36)
- Kutlu, Naciye(32)
- Artar, Musa(31)
- Can, Zehra(31)
- Korkmaz, Şadan(31)
- Yilmaz, Mustafa Tahsin(31)
- Öner, Erdal(31)
- Bayram, Sinan(30)
- Cuce, Erdem(30)
- Ertugrul, Mehmet(29)
- Hasar, Ugur Cem(29)
- Ecem Bayram, Nesrin(28)
- Mercan, Emin(28)
- Ayata, Ümit(27)
- Bayraktar, Bülent(27)
- Çolak, Murat(23)
- Özdemir, Akın(23)
- Ayazoglu, Rabil(22)
- Cuce, Pinar Mert(22)
- Sert, Durmuş(22)
- Bayram, Ozkan(21)
- Kamiloğlu, Aybike(21)
- Dirican, Ebubekir(20)
- Kadakal, Mahir(20)
- Abdioglu, Murat(19)
- Birinci, Ahmet(19)
- Tozlu, Alperen(19)
- Gerçek, Yusuf Can(18)
- Taylan, Osman(18)
- Cinar, Mehmet(17)
- Gul, Volkan(16)
- Hasar, Ugur C.(16)
- Kadakal, Huriye(16)
- Kara, Yakup(16)
Yayınlar
- MakaleAçık Erişim2024Scopus SJRQ3Machine learning driven optimization and parameter selection of multi-surface HTS Maglev
Ozkat, Erkan Caner; Abdioglu, Murat; Ozturk, U. Kemal
This research aims to tackle the challenges posed by precise force measurement for high temperature superconducting (HTS) Maglev systems, including mechanical constraints, step motor limitations, and sensor resolutions. For this aim, six machine learning (ML) models namely Support Vector Machine (SVM), Gaussian Process Regression (GPR), Extreme Gradient Boosting (XGB), Long Short-Term Memory (LSTM), Extreme Machine Learning (EML), and Convolutional Neural Network (CNN) were developed to predict levitation force (Fz) and lateral force (Fx) based on process parameters including permanent magnet width (PMW), field cooling height (FCH), the movement in the z-axis (vertical distance), and the movement in the x-axis (lateral distance). Among six ML models, CNN emerged as the most accurate model, demonstrating smaller root mean square deviation (RMSD) without compromising correlation coefficients. Furthermore, an innovative process window approach was introduced to select process parameters that simultaneously meet the minimum value of Fz and maximum value of Fx, named β1 and β2, set at 90 N and 0 N, respectively. Within this window, PMW of 30 mm and z values less than 10 mm were found to be consistent for all FCH and x values. The novelty of this study is to formulate the optimisation problem in HTS Maglev using the developed ML model by addressing two specific objectives one of which focuses on maximizing Fz while ensuring Fx remains within a defined tolerance (β3), representing the minimum allowable ratio of the levitation force to the total force, and the second problem aims to maximize Fz while obtaining zero Fx. The optimum PMW, FCH, x, and z values were obtained at 30 mm, 30 mm, 4 mm and 5 mm, corresponding to Fz and Fx values of 224.2 N and -53.8 N for option 1. As for option 2, the process parameters were obtained as 28.6 mm, 25.9 mm, 0 mm, and 5 mm, corresponding to Fz and Fx values of 194.2 N and 0 N. It was obtained both experimentally and by the optimization that Fz reaches close its maximum as the Fx gains attractive character. Hence, it is expected that the outcomes of this study will significantly benefit the design of HTS Maglev systems and find valuable applications across various transportation engineering projects.
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İncele - MakaleYalnız künye2024Scopus SJRQ1Research of the crack problem of a functionally graded layer
Yaylacı, Murat; Yaylacı, Ecren Uzun; Turan, Muhittin; Özdemir, Mehmet Emin; Öztürk, Şevval; Ay, Sevil
In this study, the two-dimensional crack problem was investigated by using the finite element method (FEM)based ANSYS package program and the artificial neural network (ANN)-based multilayer perceptron (MLP) method. For this purpose, a half-infinite functionally graded (FG) layer with a crack pressed through two rigid blocks was analyzed using FEM and ANN. Mass forces and friction were neglected in the solution. To control the validity of the crack problem model exercised, the acquired results were compared with a study in the literature. In addition, FEM and ANN results were checked using Root Mean Square Error (RMSE) and coefficient of determination (R2), and a well agreement was found. Numerical solutions were made considering different geometric parameters and material properties. The stress intensity factor (SIF) was examined for these values, and the results were presented. Consequently, it is concluded that the considered non-dimensional quantities have a noteworthy influence on the SIF. Also FEM and ANN can be logical alternative methods to time-consuming analytical solutions if used correctly.
AtıfScopus27WoS30OpenAlex6İncele - MakaleYalnız künye2024Scopus SJRQ1Effective biocatalytic synthesis of enentiopure (R)-1,2-diphenylethanol as a pharmaceutical precursor using whole-cell biocatalyst
Çakmak, Fadile; Özdemir, Akın; Dertli, Enes; Şahin, Engin
Optically active alcohols are crucial precursors. 1,2-Diarylethanols and their analogues constitute a significant group of substances of biological significance. The biocatalytic synthesis of (R)-1,2-diphenylethanol ((R)-2), which can be utilized as a precursor to important drugs, is still not at the desired level in terms of substrate amount and production process. This study asymmetrically reduced 1,2-diphenylethanone (1) using the Lactobacillus paracasei BD87E6 biocatalyst and a novel orthogonal quadratic design-embedded optimization approach. The following reaction optimization conditions were determined using the suggested optimization technique: pH = 6, temperature = 31 °C, incubation period = 48 h, and agitation speed=134 rpm. In addition, the reaction conversion was estimated to be 99.38 %, and the product's enantiomeric excess (ee) was estimated to be 99.12 %. Further, (R)-2 was produced with >99 % ee, >99 % conversion, and 98 % yield in the experimental investigation under the established optimum conditions. This study is the first attempt to reduce substrate 1 to (R) or (S)-2 using a mathematical optimization method in the presence of a biocatalyst. Furthermore, on a high-gram scale, 1 (15.70 g) was entirely transformed into (R)-2 (15.54 g, 98 % isolated yield). Notably, this study is also the first to perform the gram-scale production of (R)-2 using a novel optimization approach and a biocatalyst. Finally, the innovative and novel orthogonal quadratic design-embedded optimization technique has been demonstrated as an efficient, cost-effective, and environmentally friendly biocatalytic procedure for synthesizing (R)-2.
AtıfScopus7WoS7OpenAlex6İncele - MakaleAçık Erişim2024Scopus SJRQ1Virtual Reality Technology in Nursing Education: A Qualitative Study
Avşar, Gülçin; Çelik, Şeymanur; Doğan, Sevgi; Çiftçi, Bahar
Virtual reality (VR) technology plays a significant role in nursing education by enhancing the quality of training by applying knowledge, decision-making, intervention completion and feedback. This study aims to examine nursing students' experiences and perceptions regarding the ventrogluteal injection training provided through VR technology. Conducted between May and June 2022, this qualitative descriptive phenomenology study took place at a state university in Turkey, involving 70 students who participated in Ventrogluteal Drug Administration training using VR glasses. The sample included 12 students selected via the Criterion Sampling Method. Data collection tools comprised the ‘Descriptive Information Form’ and a ‘Semi-Structured Questionnaire’. Qualitative data were analysed using the Content Analysis Method, while quantitative data were assessed through descriptive statistical methods (frequency, percentage, mean). The study identified 13 codes, four sub-themes and two main themes from the students' evaluations. The first main theme, ‘Weaknesses of Virtual Simulation’, included two sub-themes: ‘Due to its Nature’ and ‘Due to its Technique’, resulting in five codes. The second main theme, ‘Strengths of Virtual Simulation’, was divided into two sub-themes: ‘Permanence, Integrity, and Applicability’ and ‘Emotions towards Virtual Simulation’, with eight codes identified. The findings indicate that students view VR technology positively in their education. However, they also highlighted specific issues related to the simulation's technique and inherent nature.
AtıfScopus5WoS4OpenAlex6İncele - MakaleAçık Erişim2024Scopus SJRQ1Analysis of cascade vapor compression refrigeration system using nanorefrigerants: Energy, exergy, and environmental (3E)
Yilmaz, Metin; Cimsit, Canan; Keven, Arzu; Karaali, Rabi
Nanorefrigerants are considered the most efficient heat transfer fluids for improving heat transfer properties in the refrigeration and air conditioning equipment. For the first time in this study, energy, exergy, and environmental evaluation (3E) analyses were performed by the addition of different nanoparticles to a low GWP refrigerant pair such as R290/R1233ZDE in a cascade refrigeration system. CNT, CuO, and, TiO2 nanoparticles were added to the refrigerant. The effect of nanoparticles on the cascade refrigeration system was analyzed using a model based on density changes. A detailed thermodynamic analysis was performed of the cascade refrigeration system at different evaporator temperatures and mass ratios. The power consumption of the compressor decreases as the evaporator temperature increases for all types of nanoparticles, resulting in an increase in COP values. The analyses showed that CuO nanoparticles had the highest performance. It has been observed that the energy and exergy efficiency increase as compressor work decreases with increasing mass ratios in all nanorefrigerants. In addition, the results indicated that all nanorefrigerants emit lower monthly CO2 emissions compared to the pure refrigerants. The nanorefrigerants play a crucial role in reducing energy consumption and promoting environmental protection compared to traditional refrigerants.
AtıfScopus16WoS16OpenAlex17İncele - MakaleAçık Erişim2024Scopus SJRQ1The application of deep eutectic solvents for protein extraction from bee bread (Perga)
Ecem Bayram, Nesrin; Gerçek, Yusuf Can; Kutlu, Naciye; Çelik, Saffet; Bayram, Sinan; Baştürk, Fatma Nur; Yıldırım, Nazlıcan
Bee bread is one of the basic nutrients that bees use as a protein source and is formed as a result of the fermentation of bee pollen. In the last few years, this product has become increasingly recognized and consumed among bee products due to its functional properties. However, deep eutectic solvents (DES) have attracted great interest in recent years as promising green alternatives to replace traditional solvents due to their variable viscosity, low vapor pressure, application-specific adjustability, non-flammability and chemical stability. In this study, bee bread was extracted in 12 different DES with different hydrogen bond acceptor (HBA):hydrogen bond donor (HBD) combinations. The DES combination with the highest total protein content was determined to be choline chloride (ChCl)-urea. Then, ultrasonic extraction conditions were optimized for maximum bioactive extraction in extracts prepared with ChCl-urea. The optimum conditions were found as 31.3 %, 25 min, 35 °C for ultrasonic power, extraction time and temperature, respectively. The desirability value (d) of the model was 0.83. The extracts were analyzed for total phenolic content, total protein content, individual polyphenolics, individual amino acids and individual vitamins as well as antimicrobial and antioxidant activity tests. According to the results, total protein, total individual amino acids and total individual phenolics were higher in the extracts obtained with ChCl-urea compared to the extract prepared with conventional solvent (ethanol). In conclusion, all these findings showed that ChCl-urea combination can be an alternative to ethanol depending on the structural characteristics of the target compounds to be extracted from bee bread.
AtıfScopus15WoS12OpenAlex13İncele - MakaleYalnız künye2024Scopus SJRQ3Microwave hydrodistillation of Pelargonium graveolens L’Her leaves: Essential oil profile, phytochemical composition of wastewater, histo-anatomical structure
Boztaş, Kadir; Gercek, Yusuf Can; Türer, Gizem; Canlı, Deniz; Bayram, Sinan; Çelik, Saffet; Kırkıncı, Seran; Basturk, Fatma Nur; Feizollahi, Sepideh; Cevahir Öz, Gül
By-products with remarkable bioactive properties are formed in extraction processes of essential oils from plant materials. In present study, it was aimed to determine the concentration of individual phenolic and organic acid compounds by LC-MS/MS of the by-product (wastewater) collected after the essential oil isolation from Pelargonium graveolens L. and to determine some bioactive properties of this by-product. In addition, the chemical analysis and antibacterial activity of the essential oil extracted from P. graveolens were determined and the histo-anatomical characterization of the glandular trichomes in the leaf sample was performed. As a result, quercetin (95862.22 μg/kg), myricetin (59834.32 μg/kg) and rutin (36522.90 μg/kg) were the phenolic compounds determined in the highest concentrations in the by-product extracted using two different extraction techniques (non-hydrolysis and hydrolysis methods). Moreover, the individual organic acids of the by-product screened in LC-MS/MS was found to be 4487.17 mg/kg in total. When the essential oil component profile of the plant sample was examined, the citronellol (38.78%) compound was found to be dominant, and it was also detected that the essential oil had remarkable bioactive properties. In conclusion, it can be stated that both the essential oil obtained from P. graveolens and the by-product obtained during essential oil isolation can be considered as a source of some bioactive components in many different industrial applications.
AtıfScopus6WoS4OpenAlex6İncele - MakaleAçık Erişim2024Scopus SJRQ1The Effect of Augmented Reality Technology on Primary School Students’ Achievement, Attitudes Towards the Course, Attitudes Towards Technology, and Participation in Classroom Activities
Sökmen, Yavuz; Sarikaya, İsmail; Nalçacı, Ahmet
The research aims to investigate the impact of augmented reality (AR) technologies developed within the framework of primary school students’ on student achievement, attitudes towards the course, attitudes towards technology, and participation in classroom activities. The contents of AR-based learning materials have been developed by 4th-grade teachers and writers within the context of the existing curriculum. The study process was carried out based on the instructional design model. The research was performed in conjunction with the quasi-experimental design among the experimental designs of quantitative research methods. Using the cluster random sampling method, students in the experimental and control groups were selected among 11 primary schools. The findings indicate that contrary to the students in the control group, the students in the experimental group had higher academic achievement and participation in classroom activities, and also their attitudes to the course and applied technology were more positive. Moreover, concerning the experimental group students, a positive and significant correlation between their academic achievements, attitudes towards the course, attitudes towards technology, and their participation and participation in classroom activities have been observed.
AtıfScopus24WoS16OpenAlex21İncele - MakaleAçık Erişim2024Scopus SJRQ2Biochemical and physicochemical characteristics and volatile profiles of Erzincan Tulum cheese coagulated by herb-fortified artisanal lamb rennet
Arslaner, Ayla; Türkmen, Özgenur
The characteristics of Erzincan Tulum cheese (ETC), an artisanal ewe-milk cheese and the first cheese with the designation of origin in Türkiye, are closely related to the geographical location of production and the human factors influencing every stage of the production process. This study aims to determine the influence of different coagulants (namely, herb-fortified artisanal lamb rennet (ALR), artisanal calf rennet (ACR), and commercial calf rennet (CCR)) on the biochemical, physicochemical characteristics, and volatile compounds of ETC, produced on the Heybeli plateau of the Erzincan province. Using artisanal rennet increased total solids, fat content, and acidity while decreasing pH and aw values. The highest PTA-SN (soluble nitrogen in 5 % phosphotungstic acid, w/v) and TCA-SN (soluble nitrogen in 12 % trichloroacetic acid w/w) values at the end of the ripening period (day 150 of storage) were observed in the ALR-Cheese (ALR-C). Furthermore, this cheese exhibited the highest rate of lipolysis (P < 0.01). Electrophoretograms revealed that αs-1 and β-casein degradation rates were the most significant in ALR-C. Following the 30th day of storage, the highest counts of lactic acid bacteria (LAB) were found in ALR-C. The most rapid reduction of coliforms, E. coli, and yeast-mold was observed in this sample throughout the storage. Eighty-nine volatile compounds were identified in the samples. Particularly noteworthy, ALR-C exhibited the highest ratios of hexanoic, octanoic, and decanoic acids after 90 days of storage. Additionally, steroid compounds were exclusively detected in this sample. The findings of this research make a substantial contribution to the existing literature concerning rennet types and the aromatic profile of ETC. These aspects are crucial for further investigations to enhance the cheese's quality and safety.
AtıfScopus3WoS3OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ3Exploring the Potential of Isoindole-1,3-Dione Derivatives as Novel Inhibitors of Aldose Reductase: An In Silico and In Vitro Insight into Therapeutic Strategies for Diabetic Complications
Şengül, Bülent; Gündoğdu, Özlem; Kilinç, Namık; Kishali, Nurhan
This study explores the potential of isoindole-1,3-dione derivatives as novel inhibitors of aldose reductase (AR), focusing on their in silico and in vitro effects for therapeutic strategies against diabetic complications. Aldose reductase, a critical enzyme in the polyol pathway, plays a significant role in glucose metabolism and has been linked to diabetic complications. In this comprehensive study, isoindole-1,3-dione derivatives were synthesized and evaluated for their inhibitory effects on the recombinant human AR enzyme. The compounds’ inhibitory activities were measured both in vitro and through in silico techniques, employing molecular docking and free binding energy calculations and ADME studies. The newly synthesized compounds demonstrated varied inhibitory effects, with ethyl and phenyl substituents at specific positions enhancing inhibitory activity. Notably, compounds with carboxylic acid derivatives exhibited potent inhibitory effects, especially compound 6 with an IC50 value of 1.649 μM. In conclusion, this study provides valuable insights into the inhibitory potential of isoindole-1,3-dione derivatives against AR, suggesting their potential therapeutic application in mitigating diabetic complications. The combination of experimental and computational approaches offers a comprehensive understanding of the compounds’ interaction mechanisms and pharmacokinetic profiles, supporting their further exploration as antidiabetic agents.
- MakaleYalnız künye2024Scopus SJRQ1Mindfulness-based cognitive therapy for adherence of immunosuppressive treatment in liver transplant recipients: A randomized controlled trial
Bulbuloglu, Semra; Gunes, Hüseyin
Objective: The aim of this study was to analyze the effects of mindfulness-based cognitive therapy on the adherence of liver transplant recipients to immunosuppressive therapy with a randomized controlled design. Method: This randomized controlled trial was performed with 120 liver transplant recipients hospitalized at the liver transplant department of a research and practice hospital (n = 120). While we administered no intervention to the patients in the control group (n = 60), we provided Mindfulness-Based Cognitive Therapy to those in the experimental group (n = 60). We used the Mindful Attention Awareness Scale and the Immunosuppressant Therapy Adherence Scale to collect data. We utilized descriptive statistics, paired-samples t-tests, independent-samples t-tests, one-way analysis of variance, and chi-squared tests to analyze the data. Results: After the intervention, the immunosuppressive therapy adherence levels of the experimental group increased significantly (p < 0.01). On the other hand, the control group had significantly higher adherence to immunosuppressive therapy and significantly higher levels of mindfulness in the pretest phase than it did in the posttest phase (p < 0.01). Conclusions: Complete adherence to immunosuppressive therapy is imperative for the prevention of graft rejection in liver transplant recipients. In our study, the experimental group equipped with enhanced mindfulness had higher adherence to immunosuppressive therapy. Therefore, the use of Mindfulness-Based Cognitive Therapy in the promotion of adherence to immunosuppressive therapy is recommended.
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İncele - MakaleAçık Erişim2024Scopus SJRQ2Cross-cultural adaptation and psychometric evaluation of the Turkish version of the Smombie Scale for Adolescents
Sönmez Sari, Ebru; Temel Mert, Zeynep; Semerci Çakmak, Vahide; Sevgil Atli, Pelin
Background: Smombie has become an important problem especially in terms of adolescent health. The aim of this study was to translate the Smombie Scale for Adolescents (SSA) into Turkish and to examine its psychometric properties. Methods: This study has a methodological design. The study was conducted between March and April 2024. The sample of the study consisted of 430 adolescents. The data were collected by using Personal Information Form and SSA. Content Validity Index, Confirmatory Factor Analysis (CFA), test−retest reliability, Cronbach's α coefficient, item-total score correlation, 27% upper−lower group item analysis and Hotelling T2 test were used in data analysis. Results: The four-factor structure of the scale showed a good fit in CFA (chi-square minimum discrepancy [CMIN] = 187.463, degrees of freedo (DF) = 83, CMIN/DF = 2.259, root mean square error of approximation = 0.054, root mean square residual = 0.033, goodness of fit index = 0.947, adjusted goodness of fit index = 0.923, normed fit index = 0.930, tucker-lewis index = 0.949 and comparative fit index = 0.959). Cronbach's α coefficient of the scale was found to be 0.86. The item-total score correlation of the scale was found between 0.212 and 0.721. The test-retest intraclass correlation coefficient of the scale was found to be 0.876. Conclusions: This study shows that the scale is a reliable tool for assessing adolescents' smombie tendencies. It is thought that the scale will contribute to the protection and development of adolescent health.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2024Scopus SJRQ2Investigation of the effect of green walking and intelligence games on the cognitive skills of individuals between the ages of 50–70 survived COVID-19 disease: A randomized controlled study
Akeren, Zahide; Hintistan, Sevilay
Background: Mild cognitive impairment can be considered as the preclinical stage of Alzheimer's disease. With the addition of COVID-19 disease to the cognitive decline that occurs with aging, it may cause dementia with severe cognitive losses such as Alzheimer's disease in some people. Physical activity and brain-occupying practices can significantly improve the risk factors for cognitive disorders and Alzheimer's disease. Objective: The aim of study was to examine the effect of green walking and intelligence game on the cognitive skills of individuals aged 50–70 years with COVID-19. Methods: The randomized controlled study was completed with 40 individuals, 20 in the experimental and 20 in the control group. Individuals in the experimental group green walking for 30 min three days a week for one month in two groups of 10 people, accompanied by the researcher. In addition, these individuals played intelligence games (brain games-memory thinking and brain exercise) via their smartphones for 15 min every day for a month. Results: The cognitive skills and cognitive dimensions of “attention, concentration, memory, language and orientation” of the individuals in the experimental group were significantly increased compared to the control group individuals (p < 0.05). Conclusions: It was found that green walk and intelligence game practice increased the cognitive skills of individuals aged 50–70 years who had outpatient COVID-19. © The Author(s) 2024. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (https://us.sagepub.com/en-us/nam/open-access-at-sage).
AtıfScopus1WoS2OpenAlex2İncele - MakaleAçık Erişim2024Scopus SJRQ3The effect of injectable platelet-rich fibrin in combination with autogenous bone grafts on bone healing in an ovariectomized osteoporotic rat model with critical-sized defects
Durmuşlar, Mustafa C.; Gülşen, Elif A.; Bayburt, Kemal A.; Ballı, Umut; Ocak, Mert; Fırat, Ayşegül; Zırh, Elham B.; Çelik, Hakan H.
OBJECTIVES: To assess the impact of autogenous graft materials, including autogenous bone graft (ABG) and injectable platelet-rich fibrin (I-PRF) clots, on bone defect regeneration in ovariectomized osteoporotic rats. METHODS: Wistar rats (6-8 weeks old) were ovariectomized, and surgery began after 8 weeks. A 5-mm defect was created bilaterally in the parietal bones of 16 rats, which were divided into 4 groups. Group A (blank) had untreated defects; group B had defects filled with 0.1 ml of I-PRF, group C had defects filled with 0.1 ml of ABG, and group D had defects filled with a combination of 0.1 ml each of I-PRF and ABG. Four weeks post-surgery, the rats were euthanized. Bone regeneration was evaluated through histopathologic analysis and microcomputed tomography (micro-CT). RESULTS: In ovariectomized rats treated with ABG or I-PRF, bone regeneration was enhanced, with increased periosteal activity, osteoblast count, and new bone volume, as determined histologically. The ABG+I-PRF group had the highest periosteal vascularity, but the difference compared to the ABG group was not statistically significant (p>0.05). Osteoblast numbers were significantly higher in the ABG+I-PRF group than in the blank group (p<0.05). Micro-CT showed the highest mean new bone volume ratio in the ABG+I-PRF group, followed by the ABG group. CONCLUSION: The combined use of ABG and I-PRF enhances bone formation in osteoporotic rats following ovariectomy. Copyright:
AtıfScopus2OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ2Drought analysis using innovative trend analysis and machine learning models for Eastern Black Sea Basin
Niazkar, Majid; Piraei, Reza; Eryılmaz Türkkan, Gökçen; Hırca, Tuğçe; Gangi, Fabiola; Afzali, Seied Hosein
This study aims to assess the Eastern Black Sea Basin drought conditions. For this purpose, the trend changes in SPI values of 6, 9, 12, and 24 months using innovative trend analysis were examined. Additionally, four machine learning models, including Multiple Linear Regression, Artificial Neural Networks, K Nearest Neighbors, and XGBoost Regressor, are employed to forecast SPI with rainfall data between 1965 and 2020 from eight rainfall stations. The input data for each model was SPI values from lead times of 1 to 6, resulting into 768 unique scenarios. The ML models estimated SPI values better as the SPI duration increased, with the 24-month SPI showing the highest accuracy. The results of SPI forecast indicated that the optimal model and number of input variables varied for each SPI and station, indicating that further studies are required to improve SPI predictions.
AtıfScopus24WoS23OpenAlex25İncele - MakaleAçık Erişim2024Scopus SJRQ1Effects of the demineralisation degree on physicochemical, functional, microstructural and powder flow properties of whey powder
Bebek, Müşerref; Sert, Durmuş; Mercan, Emin
This study aimed to investigate the effects of the demineralisation process on powder flow, physicochemical, functional, and microstructural properties of whey powders (WP). WP samples were produced from 50, 70 and 90% demineralised sweet whey concentrates. Although the salt, ash, and lactic acid content of the powders decreased with increasing demineralisation, pH increased. D [3,2] (surface area mean diameter) value of WP samples ranged from 28.2 to 60.9 μm, in which demineralisation increased the particle size. The colour values showed increased darkness and yellowness, attributed to the higher demineralisation process. Demineralisation improved solubility and foaming characteristics, whereas it decreased the wettability and dispersibility of samples. The caking and cohesion characteristics of WP were significantly decreased by demineralisation. Demineralisation significantly improved the powder flow characteristics of samples. The cohesion index decreased depending on the demineralisation degree increased. Also, demineralisation decreased the cake strength and compaction coefficient of samples. Mineral content decreased with increasing demineralisation, with some minerals showing more sensitivity to demineralisation than others. Scanning Electron Microscope images showed reduced caking and clustering in samples with higher degrees of demineralisation. The results highlighted the importance of demineralisation as an effective parameter to control the properties of WP. In conclusion, this study demonstrated that the degree of demineralisation had a substantial impact on the physical and functional properties of WP.
AtıfScopus1WoS1OpenAlex3İncele - MakaleYayıncıda açık erişim2024Scopus SJRQ3Comparison of Color Parameters in Layers of Yacht Varnish, Waxy Varnish, and Stone Varnish Applied to Various Wood Species
Ayata, Ümit; Peker, Hüseyin
In this study, solvent-based yacht varnish, stone varnish, and waxy varnish were applied in two coats using a brush, following industrial application standards, to the surfaces of the following tree species: black alder (Alnus glutinosa L. Gaertn.), curupay (Anadenanthera macrocarpa Benth.), iatandza (Albizia ferruginea), lemon (Citrus limon (L.) Burm.), loquat (Eriobotrya japonica L.), magnolia (Magnolia grandiflora L.), plane (Platanus orientalis L.), sucupira (Bowdichia nitida Benth.), and hornbeam (Carpinus betulus L.). Subsequently, the color parameters (b*, C*, L*, a*, ho, ΔE*, ΔH*, Δb*, ΔC*, Δa*, and ΔL*) of the varnish layers were compared with those of the untreated surfaces. The results of analysis of variance revealed significant differences in all color parameters. Decreases in L* values and increases in a* values were observed for all wood types when treated with three different varnishes. Additionally, in plane, black alder, and hornbeam wood, application of all varnishes resulted in increases in b* and C* values, with decreases in ho values. In sucupira wood, however, decreases were observed in b*, C*, and ho values with the application of all three varnishes. It was observed that a single type of varnish yielded different results on different wood types. This finding was attributed to the different types of resins present in the varnish types used in the study, which resulted in varying outcomes.
- MakaleAçık Erişim2024Scopus SJRQ2Investigating the Effect of Polypropylene Fiber on Mechanical Features of a Geopolymer-Stabilized Silty Soil
Kamiloğlu, Hakan A.; Kurucu, Kutluhan; Akbaş, Dilek
This study investigates the stabilization of silty soil using alkali-activated fly ash and fibers with lengths of 3 mm and 12 mm. The study examines the effects of hybrid fiber length, fiber content, fly ash content, and activator content on the mechanical properties of the geopolymerstabilized samples. The objectives of this paper are 1) to examine the effect of activator content and fly ash content on the UCS, Al/Si ratio, and SiO2/Na2O ratio of the stabilized samples using a statistical approach, 2) to investigate the effect of hybrid fiber length on UCS, secant modulus, flexural strength, toughness, and flexural load-deformation characteristics of the stabilized soil. A statistical approach was employed to investigate the relationship between fly ash content, alkali activator content, and UCS value. Optimal fly ash content and alkali activator content were determined based on the statistical model. The geopolymer structure of the stabilized soil was characterized via SEM, EDS, XRD, and FTIR analyses. The effects of fly ash and alkali activator content on UCS, Al/Si ratio, and SiO2/Na2O ratio were determined using the derived statistical model. The study demonstrated that activator content, a critical factor in compaction, significantly influences the UCS value, as much as the effect of the Si/Al and SiO2/Na2O ratios. Additionally, variations in fly ash content led to an increase in the UCS value of up to 15%. Moreover, changing the activator content resulted in a maximum 12-fold increase in UCS value. Incorporating hybrid fibers for stabilization led to higher secant modulus (up to 30%), flexural strength (up to 6%), and ductility without compromising UCS.
AtıfScopus20WoS17OpenAlex18İncele - MakaleAçık Erişim2024Scopus SJRQ2The relationship between self-efficacy and emotional burnout levels of seafarers: the role of individual alienation – the case of Turkey
Battal, Fetullah; Durmuş, İbrahim; Çınar, Ertuğrul
Purpose: The study aims to examine the factors that may affect the burnout levels of ship workers. Design/methodology/approach: The scope of the research consists of seafarers on ships docking at the ports of Zonguldak, Karadeniz Eregli, Eren and Filyos in the Western Black Sea region of Turkey. The sample consists of officers, engineers, dynamic position operators, electricians, boatswains, able seamans, pumpmans and stewards working on ships. In this respect, a random questionnaire was used in the research method and a questionnaire was sent to 400 of these employees, representing the main sample, and 263 of them fully answered the online questionnaire. Findings: As a result of the research, first of all, it is seen that the increase in the self-efficacy of the seafarers decreases their emotional burnout levels. In the second step, the strong self-efficacy of the seafarers reduced the level of individual alienation. In the third step, the increase in the individual alienation of the ship workers also caused an increase in the levels of emotional exhaustion. Originality/value: As a result, it has been seen that there is a partial mediating role of individual alienation in the relationship between the self-efficacy of the seafarers and their emotional exhaustion. In other words, high self-efficacy is not the only reason for the decrease in emotional burnout levels among seafarers. At the same time, self-efficacy has an effect on the individual alienation levels of seafarers.
AtıfScopus1WoS1OpenAlex2İncele - MakaleYalnız künye2024Scopus SJRQ2Diltiazem and Verapamil: Combined experimental and computational approaches to structural and spectroscopic characterization
Cinar, Mehmet; Can, Sümeyra; Baris, Özlem; Demirci, Çiğdem Elif
Diltiazem and Verapamil are two important drug molecules in a separate group of Calcium Channel Blockers. The purpose of this work is to determine and compare the structural and spectroscopic properties of these two molecules using a number of experimental techniques and quantum chemical calculations. Compounds were characterized spectroscopically using FT-IR, Raman, NMR (1H, 13C, and DEPT), and UV–vis methods. Furthermore, the Density Functional Theory (DFT) method, Becke's three-parameter hybrid functional (B3LYP), and the 6–311++G(d,p) basis set were used to determine the ground state geometric structures of molecules, and the spectroscopic properties of the obtained optimum structures were investigated computationally. The optimization studies performed under vacuum circumstances and for the isolated molecules were found to be very close to the experimental results. In fact, r.m.s. values were discovered for Diltiazem and Verapamil with bond lengths of 0.013 and 0.024, and bond angles of 1° and 2°, respectively. The vibration characteristics of the compounds were discovered using the collected FT-IR and Raman spectra, and significant vibrational modes were assigned. After scaling, it was revealed that the quantum chemical data was congruent with the experimental ones, and that the characteristic vibrational modes were appropriately predicted. DFT calculations effectively determine molecules' structures due to internal consistency, despite being slightly distant from experimental data. Theoretical values for carbon and hydrogen atoms are better in agreement with observed values when scaling with 0.92 and 0.90. From the UV–vis spectra, Diltiazem HCl absorbance peaks were found at 207 and 237 nm, whereas Verapamil HCl absorbance peaks were identified at 203, 229, and 278 nm. When the theoretical calculations and experimental findings were compared, the anticipated absorption peaks were found to have shifted nearer the visible area. Furthermore, Hirshfeld surfaces and Molecular Electrostatic Potential surfaces were obtained and analyzed in order to better understand the electronic characteristics. The TDOS and PDOS (total and partial density of state) spectra were also studied. Finally, using the HOMO and LUMO energy values, the critical chemical parameters were evaluated, and it was discovered that both molecules had positive electron affinity and electronegativity values, indicating that they will accept electrons when the electron-nucleus attraction exceeds the electron-electron repulsion.
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