Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Kamiloğlu, Aybike(6)
- Kutlu, Naciye(6)
- Ecem Bayram, Nesrin(5)
- Bayram, Ozkan(4)
- Bayram, Sinan(4)
- Igman, Erdal(4)
- Teber, Ahmet(4)
- Tutkun, Cansu(4)
- Dertli, Enes(3)
- Elbir Abca, Tuğba(3)
- Gerçek, Yusuf Can(3)
- Guleryuz, Didem(3)
- Simsek, Onder(3)
- Çolak, Murat(3)
- İspirli, Hümeyra(3)
- Abdioglu, Murat(2)
- Ari-Arat, Ceren(2)
- Can, Zehra(2)
- Ekincioğlu, Yavuz(2)
- Eryılmaz Türkkan, Gökçen(2)
- Güven, Ebru Mazlum(2)
- Güven, Onurhan(2)
- Hasar, Ugur Cem(2)
- Hırca, Tuğçe(2)
- Kara, Yakup(2)
- Kolaylı, Sevgi(2)
- Kotaman, Hüseyin(2)
- Kızıl, Hamit Emre(2)
- Niazkar, Majid(2)
- Sarac, Mehmet Fahri(2)
- Sayan, Enes(2)
- Yaman, Havva(2)
- Yetişensoy, Okan(2)
- Yılmaz, Özlem(2)
- Çakiroğlu, Ünal(2)
- Abdolahpour Salari, Maryam(1)
- Adiyaman, Gokhan(1)
- Afzali, Seied Hosein(1)
- Akaras, Nurhan(1)
- Akgun, Nurullah(1)
Yayınlar
- MakaleYalnız künye2023Scopus SJRQ2Cr-substituted nanocrystalline Ni–Co ferrites: tuning dielectric, magnetic, structural, X-band microwave absorption, and characteristic properties
Teber, Ahmet; Sarac, Mehmet F.
The structural, characteristic, dielectric, and magnetic features of Co0.5Ni0.5CrxFe2 − xO4 (0.0 ≤ x≤ 1.0 with a step of 0.2 x-concentration) nanoparticles are prepared via the hydrothermal method. The investigation of characteristics, structural, and magnetic features of the produced nanoparticles are examined through XRD, FT-IR, SEM–EDS, TEM-SAED, and VSM, respectively. AC conductivity and the dielectric investigations are also reported. According to the XRD measurements, all samples have the M-type hexagonal crystal structure nanocrystallites of between 27 and 97 nm. Refined structural parameters using Rietveld analysis are carried out using the TOPAS refinement program. A good match was observed between the diffraction patterns obtained and calculated by Rietveld analysis. Moreover, the morphological analyses indicate that the relatively small spherical structures of Ni–Co ferrites particles can be seen to change from spherical to relatively oval-shaped with increasing chromium content. The results of the FT-IR study show that the spinel structure has formed as predicted because the expected range of absorption bands is present. According to magnetic measurements, Cr-substituted Ni–Co ferrite nanostructures reveal a relatively soft ferromagnetic property. The coercive field (Hc) variation has a propensity to decrease in relation to the Cr-concentration. The electromagnetic constitutive parameters are calculated from measured S-parameters (S11 and S21) using network analyzer and the return losses of the samples are then obtained to determine microwave absorption properties. According to the dielectric and magnetic tangent losses or dissipation factors, both dielectric and magnetic features can mutually reinforce in terms of microwave absorption properties in the X-band. The Cr2O3 impurity peaks obtained by XRD analysis have an effect on the microwave absorption properties. The results of the microwave absorption based on each concentration reveal that there exist electromagnetic wave absorptions between approximately 11 GHz and 12.4 GHz in the X-band. The absorption trend is also towards the Ku-band.
AtıfScopus3WoS3OpenAlex3
İncele - MakaleAçık Erişim2023Scopus SJRQ1Face presentation attack detection performances of facial regions with multi-block LBP features
Günay Yılmaz, Asuman; Turhal, Uğur; Nabiyev, Vasif
Biometric recognition systems are frequently used in daily life although they are vulnerable to attacks. Today, especially the increasing use of face authentication systems has made these systems the target of face presentation attacks (FPA). This has increased the need for sensitive systems detecting the FPAs. Recently surgical masks, frequently used due to the pandemic, directly affect the performance of face recognition systems. Researchers design face recognition systems only from the eye region. This motivated us to evaluate the FPA detection performance of the eye region. Based on this, in cases where the whole face is not visible, the FPA detection performance of other parts of the face has also been examined. Therefore, in this study, FPA detection performances of facial regions of wide face, cropped face, eyes, nose, and mouth was investigated. For this purpose, the facial regions were determined and normalized, and texture features were extracted using powerful texture descriptor local binary patterns (LBP) due to its easy computability and low processing complexity. Multi-block LBP features are used to obtain more detailed texture information. Generally uniform LBP patterns are used for feature extraction in the literature. In this study, the FPA detection performances of both uniform LBP patterns and all LBP patterns were investigated. The size of feature vector is reduced by principal component analysis, and real/fake classification is performed with support vector machines. Experimental results on NUAA, CASIA, REPLAY-ATTACK and OULU-NPU datasets show that the use of all patterns increased the performance of FPA detection.
AtıfScopus18WoS11OpenAlex19
İncele - MakaleYalnız künye2023Scopus SJRQ2Effective Damping Coefficient of Fluid Viscous Dampers for Dynamic Response Mitigation of Coupled Frames
Düzgün, Oğuz Akın; Hatipoğlu, Yavuz Selim
Purpose: In this study, the effective damping coefficient of the fluid viscous dampers (FVDs) used for coupling two adjacent multi-story frames was investigated, considering soil-structure interaction (SSI) effects under seismic excitation. Methods: A numerical procedure was employed to obtain the dynamic response of the interconnected frames-soil system. The two-dimensional (2D) finite elements were used for the numerical treatment of the adjacent frames and soil region. Viscous boundary conditions were used as special non-reflecting boundaries on the edges of finite soil region. Five different damping coefficients of FVDs are considered to determine the effective damping coefficient. The effective damping coefficient of FVDs was determined by comparing the results from coupled frames with those of the uncoupled frames. Results: The results showed that the most affecting parameter on the system response was found to be soil type. It was also found that the sufficient damping coefficient of the viscous damper is equal to 1 × 105 N s/m for minimum response. Conclusion: When the effective damping coefficient of the FVDs was provided, the maximum values of the roof displacements, the roof accelerations, and the base shear forces are found to decrease by more than 40%.
AtıfScopus3WoS2OpenAlex4İncele - MakaleYalnız künye2023Scopus SJRQ2Ultra-thin reflective multifunctional polarization converter with nested circular ring-shaped metasurface-based for C- and X-band applications
Kaya, Yunus
This article presents a single-layer, ultra-thin and multifunctional polarization converter (PC) design using metasurface. The PC, which is proposed as a single layer, consists of a metal metasurface on the front side of a easily accessible FR-4 material and a metal termination on the back surface. The suggested PC features linear polarization (LP) characteristic within a frequency ranges of 5.21- 5.41 GHz and 7.53- 8.08 GHz in C-band, also 10.59- 10.84 GHz in X-band under normal incidence. It indicates the conversion performance of linear polarization to circular polarization (LP-CP) that has the properties of left-handed circular polarization (LHCP) in frequency range of 5.74–7 GHz in C-band and right-handed circular polarization (RHCP) in frequency range of 8.63- 10.15 GHz in X-band. Besides, the suggested PC provides more than 90% polarization conversion ratio (PCR) value in case of normal incidence (0∘) and over 80% PCR value in case of oblique incidence up to 45∘. Again, the suggested PC offers the same CP feature in two frequency regions where CP conversion takes place under normal incidence for angle of incidence up to 60∘. A prototype of suggested PC was produced, measured, and a good match was found between the results simulated via a commercial electromagnetic (EM) simulation program. Finally, the performance of suggested design is compared with existing studies in literature with its high aspects. In this context, the suggested PC may be useful for C- and X-band applications due to its simple structure, ultra-thin and compactness, low-cost, and performance of LP and CP conversion under wide oblique angles.
AtıfScopus4WoS3OpenAlex3İncele - MakaleAçık Erişim2022Scopus SJRQ1Molecular Cloning, Expression and Characterisation of a Bacterial Myrosinase from Citrobacter Wye1
Cebeci, Fatma; Mayer, Melinda J.; Rossiter, John T.; Mithen, Richard; Narbad, Arjan
Glucosinolates are plant natural products which on degradation by myrosinases give rise to the beneficial bioactive isothiocyanates. Recently, a myrosinase activity was detected in a Citrobacter strain isolated from soil. This enzyme was purified enabling its amino acid sequence and gene sequence (cmyr) to be determined. In order to study this myrosinase it was necessary to establish an expression system that would enable future work such as a structural determination of the protein to be carried out. The myrosinase gene was amplified, cloned and expressed in Escherichia coli with a 6XHis-tag. The heterologous expression of cmyr enabled relatively large amounts of myrosinase to be produced (3.4 mg cmyr/100 ml culture). Myrosinase activity was determined by mixing substrate and enzyme and determining glucose release. Optimum pH and temperature were determined to be pH 6.0 and 25 °C for the Ni-NTA purified protein. The kinetic parameters of the purified myrosinase were determined using sinigrin as a substrate. Km and Vmax were estimated as 0.18 mM and 0.033 mmol/min/mg respectively for sinigrin under optimum conditions and compared to other kinetic data for myrosinases. The substrate specificity of myrosinase was determined having the highest affinity for sinigrin followed by glucoiberin, progoitrin, glucoerucin, glucoraphanin and glucotropaeolin.
AtıfScopus21WoS14OpenAlex16İncele - MakaleAçık Erişim2022Scopus SJRQ2What Should Be the Ideal Solvent Percentage and Solvent-Propolis ratio in the Preparation of Ethanolic Propolis Extract?
Kara, Yakup; Can, Zehra; Kolaylı, Sevgi
The biological activity of propolis is mostly due to its polyphenols. Raw propolis is consumed after being extracted in various solvents, ethanol being the most commonly used. However, the ideal percentage and ratio of ethanol for use in the preparation of propolis extracts are uncertain. The aim of this study is to compare the phenolic compositions and antioxidant activities of propolis extracts extracted with different ethanol concentrations and extraction conditions. Two different extraction methods were used, normal and ultrasonic extraction. The propolis extracts were evaluated in terms of total phenolic content, total flavonoid content, ferric reducing/antioxidant power,1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, and phenolic compositions using RP-HPLC–PDA. The propolis extracts with the highest activity were determined beforehand by preparing ethanol–water mixtures at different percentages, ranging from 0 to 99.9%. The most suitable propolis-to-solvent ratio was then determined. The optimum ethanolic percentage varied between 60 and 70%, the ultrasonic extraction process increased the efficiency, and the ideal solvent-propolis ratio (w/v) ranged between 1:5 and 1:10.
AtıfScopus39WoS33İncele - MakaleAçık Erişim2022Scopus SJRQ3A comparative characterization study between fungal and bacterial eumelanin pigments
Bayram, Sinan
Melanins are the most common and the most enigmatic natural pigments in the nature that found in many different taxa group such as bacteria, yeasts, fungi, insects, plants, reptiles, birds and mammals. These biological macromolecules are highly complex cross-linked, heterogeneous biopolymers and composed of polymerized phenolic and/or indolic compounds. Recently, interest in these ubiquitous biopolymers has been increasing considerably in many different areas such as medicine, pharmacology, cosmetics, organic electronic and optoelectronics because of their versatile properties. In this study, four different extracellular eumelanin pigments (two bacterial eumelanins and two fungal eumelanins) were characterized by different spectrometric techniques such as FT-IR, XRD, NMR and UV-vis. In XRD analyzes, purified fungal and bacterial eumelanin pigments were characterized by giving a wide peak at about 22o with an angle of 2θ. Furthermore, in the 1 H NMR spectra of these biopolymers, it was observed that all pigments have signals in both aromatic and aliphatic regions. In addition to these analyzes, nanostructures of these biopolymers were characterized using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Finally, eumelanin pigment producer microorganisms were molecularly characterized. 16 S rDNA and 18 S rDNA sequence analysis results of these microorganisms (Streptomyces fulvissimus MPPS4, Streptomyces xiamenensis MPPS6, Aspergillus niger MPPF16 and Aspergillus terreus MPPF25) were deposited in NCBI GenBank® database with accession number MT825594, MT973972, MW652652 and MW652653 respectively.
AtıfScopus16WoS13OpenAlex14İncele - MakaleAçık Erişim2022Scopus SJRQ2Estimation of soil temperatures with machine learning algorithms—Giresun and Bayburt stations in Turkey
Guleryuz, Didem
Since soil temperature (ST) is one of the most critical determinants affecting the soil’s physical and chemical properties, the studies on soil temperature estimation increase with the widespread use of deep learning and machine learning algorithms. This study estimates soil temperature at four depths for Giresun and Bayburt stations in Turkey employing the Bayesian Tuned Gaussian Process Regression (BT-GPR), Bayesian Tuned Support Vector Regression (BT-SVR), and Long Short Term Memory (LSTM) models. The stations were selected from semiarid (Bayburt station) and very humid (Giresun station) climates to compare the models’ performance and measure their applicability in different climate classes. Common meteorological indicators were determined as input parameters in the developed models, and a five-and-a-half-year daily dataset was used for all models. This paper represents a novel scheme to optimize the hyperparameters of kernel functions for GPR and SVR models using the Bayesian optimization method to expand predictive efficiency. The developed GPR and SVR models’ outputs are compared with LSTM via three statistical metrics comprising the root mean square error (RMSE), mean absolute error (MAE), and the coefficient of determination (R2). The results show that the BT-GPR model has a superior estimation ability than other developed models for the two stations. The daily ST estimation with the highest accuracy was obtained at a 5-cm depth using BT-GPR at Giresun station (RMSE = 0.0439, R2 = 0.9535, MAE = 0.0344 in the testing phase) and Bayburt station (RMSE = 0.0525, R2 = 0.9438, MAE = 0.0412 in the testing phase). These outcomes provide helpful benchmarking guidance for future soil temperature investigation at various depths across the selected regions.
AtıfScopus12WoS14OpenAlex21İncele - MakaleYalnız künye2022Scopus SJRQ2Optimized Machine Learning Algorithms for Investigating the Relationship Between Economic Development and Human Capital
Ozden, Erdemalp; Guleryuz, Didem
In Economic Development, human capital was previously seen as production factors but gradually evolved into endogenous growth theories. Most of the previous studies have examined the relationships between economic development and human capital via econometric models. Since this relationship is usually nonlinear and machine learning (ML) models can resolve it better, this study investigates the relationships by employing ML methods to provide a new perspective. For this purpose, the optimized ML methods, namely Bayesian Tuned Support Vector Machine and Bayesian Tuned Gaussian Process Regression (BT-GPR), were performed to develop the prediction model for economic development. The hyperparameters have been optimized with the Bayes method by using different kernel functions to increase SVM and GPR methods' predictive performance. The Multiple Linear Regression model has been employed to make a comparison as an econometric model. The performance of the models is evaluated using three statistical metrics, namely, the root mean square error (RMSE), mean absolute error (MAE), and coefficient of determination (R2). The BT-GPR with the exponential kernel model has superior prediction ability with the highest accuracy (R2: 0.9727, RMSE: 0.4022, MAE: 0.3728 in the testing phase). The study shows that the BT-GPR model increases the accuracy of R2 6.4%, RMSE 10.7%, and MAE 1% compared with other developed models.
AtıfScopus27WoS18OpenAlex30İncele - MakaleAçık Erişim2022Scopus SJRQ1Emerging trends of online assessment systems in the emergency remote teaching period
Topuz, Arif Cem; Saka, Eda; Fatsa, Ömer Faruk; Kurşun, Engin
The COVID-19 pandemic caused many educational institutions in the world to switch to the distance education process, and this process was called "Emergency Remote Teaching". This urgent transition process has caused many problems in educational environments. One of the problems is the subject of measurement and evaluation. Along with the pandemic, many institutions have used various online assessment systems to make measurements and evaluations online, and researchers have conducted research on these online assessment systems. This research focus on the features of the online assessment systems and aims to examine the trends towards the prominent features of the online assessment systems in the Emergency Remote Teaching period. For this purpose, the prominent online assessment systems have been determined by systematically analyzing academic studies published in 2020, and answers have been sought to the following research questions: (1) which platforms they support, (2) which security features they have, and (3) what common features they have. Identifying trends in the characteristics of online assessment systems is expected to guide practitioners, decision-makers, researchers, and system developers in the process of selecting and/or developing an online assessment system for use in online measurement and evaluation.
AtıfScopus37WoS20OpenAlex45İncele - MakaleAçık Erişim2022Scopus SJRQ1Charity Social Media Marketing and Its Influence on Charity Brand Image, Brand Trust, and Donation Intention
Bilgin, Yusuf; Kethüda, Önder
This study aims to identify the outline of charity social media marketing (SMM) and to determine to what extent it influences the charity brand image, brand trust, and donation intention. The data were gathered from followers of internationally operating Turk charities on social media. The theoretical model and hypotheses were tested by using structural equation modeling. Charity SMM is composed of awareness, interaction, timeliness, informativeness, customization, and advertisement dimensions. Awareness is the only dimension of SMM that has a significant direct influence on donation intention. Timeliness, informativeness, and advertisement significantly influence charity brand image, whereas brand trust is influenced by informativeness and customization. Besides, Charity SMM, as a whole, influences donation intention both directly and indirectly through brand image and brand trust. Therefore, charity brand image and brand trust are crucial for charities to promote donation intention through SMM. Therefore, charities are strongly recommended to focus primarily on developing their brand image and gaining trust in current and prospective donors.
AtıfScopus63WoS49OpenAlex69İncele - MakaleYalnız künye2022Scopus SJRQ2Applications of innovative polygonal trend analyses to precipitation series of Eastern Black Sea Basin, Turkey
Hırca, Tuğçe; Eryılmaz Türkkan, Gökçen; Niazkar, Majid
Examining historical variations of hydroclimatic variables can provide crucial information about changes of water resources in a water cycle. In this study, the Mann–Kendall (MK) and Innovative Polygon Trend Analysis (IPTA) methods were applied to 56-year precipitation data collected at 8 measuring stations. These stations are located in Eastern Black Sea Basin (EBSB), which has a significant amount of annual precipitation and hydroelectric potential in Turkey. This study has two objectives: (1) investigating possible changes in the monthly precipitation and (2) comparing the results achieved by a classical (MK) and one of the latest trend analysis methods presented in the literature (IPTA). Based on the results, MK achieved no trend for most of months, while it reached an increasing trend for March at most of the stations. Likewise, IPTA determined an increasing trend for March precipitation. However, an increasing/decreasing trend was obtained by IPTA for most of the months and stations. In other words, comparing the trend analysis results obtained by IPTA and MK indicates a significant discrepancy between the numbers of months with detected trends primarily because the former is relatively more sensitive in trend identification. To be more precise, IPTA and MK determined trends in approximately 81.25% and 12.5% of all months, respectively. Furthermore, the former identified quite the same trends in every month which the latter reported a trend. Moreover, the polygon of the mean and standard deviation graphs developed by IPTA provides a year cycle, which brings about useful information for water utility sectors and decision makers of the study area. Finally, the findings of this study contribute to a large amount of research that attempts to explore spatio-temporal variations of hydroclimatic variables around the globe not only to enhance humans’ knowledge about changes in a water cycle but also assess climate change impacts.
AtıfScopus54WoS50OpenAlex64İncele - MakaleYalnız künye2022Scopus SJRQ1Avanafil as a Novel Therapeutic Agent Against LPS-Induced Acute Lung Injury via Increasing CGMP to Downregulate the TLR4-NF-κB-NLRP3 Inflammasome Signaling Pathway
Aydin, Pelin; Magden, Zeynep Berna Aksakalli; Uzuncakmak, Sevgi Karabulut; Halici, Hamza; Akgun, Nurullah; Mendil, Ali Sefa; Mokhtare, Behzad; Cadirci, Elif
Aim: We demonstrate the effect of PDE5 inhibitors in cases of acute lung injury via the relationship between cGMP/NO and the TLR4-NF-κB-NLRP3 pathway. Materials and Methods: This study was performed with 30 male Wistar albino rats. Lipopolysaccharide (LPS) was administered intratracheally to the rats and acute lung injury (ALI) was induced. Twelve hours after LPS administration, avanafil, prepared at suitable doses according to the body weights of the animals, was administered by oral gavage. Lung tissue samples of all groups were examined histopathologically and by immunochemical staining (IL-1β, iNOS, TLR4, and NF-κB). The iNOS, NLRP3, and IL-1B mRNA expression levels in the lung tissues were measured by RT-PCR. The left upper lobes of the rat lungs were dried at 70 °C for 48 h and lung water content was calculated. Result: Statistically significant increases in iNOS, NLRP3, and IL-1β mRNA expressions were observed in the rats with ALI compared to the healthy controls (p < 0.0001). Those increased expressions were reduced at both doses of avanafil (p < 0.0001). This reduction was found to be greater at 20 mg/kg (p < 0.0001). IL-1β, iNOS, TLR4, and NF-κB immunopositivity was moderate/severe in the ALI group and mild in the group with ALI + avanafil at 20 mg/kg (p < 0.05). When the wet/dry lung ratios were calculated, a statistically significant increase was seen in the ALI group compared to the healthy rats (p < 0.05). That increase was decreased with both avanafil doses (p < 0.05). Conclusion: We suggest that avanafil may prevent the progression of ALI and be effective in its treatment. We hope that this study will be supported by future clinical studies to yield a new indication for avanafil.
AtıfScopus18WoS21OpenAlex17İncele - Derleme MakaleAçık Erişim2021Scopus SJRQ2Investigation of the Effect of Inoculant and Casting Temperature on Fluidity Properties in the Production of Spheroidal Graphite Cast Iron
Çolak, Murat; Kaya, Sinan
Working with liquid metal makes the casting method very advantageous, but also presents some difficulties. One of the common challenges in the casting process is that the liquid metal may not fill the mold cavity completely. This is mainly due to the contact of the liquid metal with the mold surface in the mold cavity, the high heat transfer coefficient of the mold material, and the undercooling and solidification of the liquid metal during liquid movements. For this reason, the fluidity of the liquid metal is important for robust casting production. The fluidity is affected by many factors such as mold properties, casting temperature, and alloying elements. In this study, it is aimed to investigate the fluidity characteristics of GGG60 alloy. For this purpose, the effects of casting temperature, different inoculants, and different inoculant quantities were used in the new mold design, which has different cross-sectional thicknesses. The distance of the alloy in the cavities was also compared with FlowCast Casting simulation software.
AtıfScopus8WoS8OpenAlex9İncele - MakaleAçık Erişim2021Scopus SJRQ2Photoluminescence and structural properties of zirconium dioxide thin films produced by RF sputtering technique
Bakacak, Pinar K.; Gur, Emre; Bayram, Ozkan; Tuzemen, Sebahattin; Simsek, Onder
In this study, Zirconium Oxide (ZrO2) thin films were produced by using radio frequency magnetron sputtering method on glass substrate at various pressures. The effects of growth pressure on the characteristics of grown Zirconia nanostructures were investigated by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Uv-Visible Spectroscopy and Photoluminescence Spectrometry (PL). XRD analysis showed that peaks of the monoclinic and tetragonal phases were more effective at low growth pressure, but different monoclinic phase peaks were present at increasing growth pressures. The surface morphological properties of the films such as average and maximum roughness, changed significantly with increasing growth pressure, and the maximum peak height first increased to 40 nm and then decreased to 20 nm. The optical transmittance of these thin films was examined in the 450–1100 nm wavelength range, covering both the visible and near-infrared spectral range, and it was found to be approximately 95% at 550 nm wavelength, and the optical band gaps were calculated to be approximately 3.26 eV by PL analyses. Uv-Visible spectroscopy analysis showed that the refractive index of the Zirconia films decreases from 2.09 to 1.79 with increasing wavelength of the incident photon. ZrO2 thin films are considered potential materials for transparent electronic devices because of their high transmittance value.
AtıfScopus5WoS4OpenAlex5İncele - MakaleAçık Erişim2021Scopus SJRQ1Extraction of Phenolic Compounds from Cornelian Cherry (Cornus mas L.) Using Microwave and Ohmic Heating Assisted Microwave Methods
Kutlu, Naciye; Isci, Asli; Sakiyan, Ozge; Yilmaz, Asim Egemen
In this study, it was aimed to extract bioactive compounds (phenolics and anthocyanins) from cornelian cherry (Cornus mas L.) using microwave (ME) and ohmic heating assisted microwave extraction (OH-ME) as an alternative to maceration (M). Total phenolic compound (TPC), total monomeric anthocyanin content (TMAC), antioxidant activity (AA), water-soluble solid matter (WSSM), color values, and pH of the extracts were determined. The effect of extraction time, solid to solvent ratio, microwave power, electrical field strength, and holding time during ohmic heating on extraction characteristics was investigated for different methods. Ohmic heating application prior to extraction has enhanced the TPC yield by 1.1 and 5.4-folds compared to that of ME and M, respectively. Moreover, the extraction time was decreased by approximately 42 and 95% as regards ME and M, respectively. The highest TMAC value (0.65 mg cya-3-glu/g dry matter) was observed with OH-ME. The experimental data obtained by ME and OH-ME methods was fitted to the Peleg model to describe the TPC yields. These results indicate that the combined application of ohmic heating and microwave extraction is a potential alternative method for total phenolic compounds extraction from cornelian cherry due to increased yields and reduced extraction times.
AtıfScopus48WoS40OpenAlex47İncele - MakaleAçık Erişim2021Scopus SJRQ2Effect of a Training Program about Noticing and Expressing Feelings on Forgiveness
Kaya, Feridun; Odacı, Hatice
This study aimed to investigate the effect of training about noticing and expressing feelings on individual tendency to forgive. The experimental and control groups in the research comprised 34 students, 18 female and 16 male with ages from 19 to 23 years (M = 21.00, SD =.65), attending Bayburt University. Data collection tools included the Heartland Forgiveness Scale and the Personal Information Form prepared by the researchers. The research was completed in accordance with a random, pre-test-post-test control group experimental model. The one-way analysis of covariance (ANCOVA) was utilized for data analysis. The results showed that the training program about noticing and expressing feelings had a significant effect on individuals’ forgiveness. In addition, the mean of the forgiveness post-test scores for individuals enrolled in the training program were found to be higher than the post-test scores for individuals who did not participate.
AtıfScopus4WoS3OpenAlex3İncele - MakaleAçık Erişim2021Scopus SJRQ1Photovoltaic performance of non-covalent functionalized single-layer graphene in dye-sensitized solar cells (DSSCs)
Igman, Erdal; Bayram, Ozkan; Mavi, Ahmet; Hasar, Ugur Cem; Simsek, Onder
In this study, it was aimed to fabricate new effective alternative counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). For this purpose, firstly, single-layer graphene (SLG) thin films were grown by chemical vapor deposition (CVD) method. Then, these films were separately functionalized with 1,8-cineole (ppCin/SLG), D-Limonene (ppLim/SLG) and Thiophene (ppTh/SLG) by plasma polymerization. Number of layers in CVD-grown graphene determined by Raman, transmission electron microscope (TEM) and ultraviolet–visible (UV–Vis) spectroscopy. Chemical structures of plasma polymerised (pp) thin films were investigated by Fourier transform infrared (FTIR) spectroscopy. Photovoltaic parameters of DSSCs were calculated, and electrocatalytic properties of CEs were investigated by electrochemical impedance spectroscopy (EIS). Polymer functionalization greatly enhanced the electrical conductivity and electrocatalytic activity properties of graphene compared to that of SLG. The efficiencies of DSSCs with ppCin/SLG and ppLim/SLG CEs were 1.10% and 1.02%, respectively. As a result, the cell efficiencies of ppCin/SLG and ppLim/SLG could be as alternative materials to platinum (Pt) counter electrode.
AtıfScopus14WoS13OpenAlex14İncele - MakaleAçık Erişim2021Scopus SJRQ2The effects of adding Hibiscus sabdariffa L. flowers marmalade on some quality properties, mineral content and antioxidant activities of yogurt
Arslaner, Ayla; Salik, Mehmet Ali; Bakirci, İhsan
In this study, the effect of Hibiscus sabdariffa L. flowers marmalade (HM) addition at different ratios (0%, 15%, 20%) was determined on the certain quality properties, total phenolic contents, antioxidant activity, mineral composition and heavy metal content of stirred-type yogurts (C, HM15, and HM20). The marmalade addition increased dry matter, ash, titratable acidity and viscosity whereas decreased pH, fat and protein values. HM addition significantly increased the antioxidant properties of yogurt samples. 2,2-Diphenylpicrylhydrazyl radical-scavenging activity, Copper (II) reducing antioxidant capacity and total phenolic content were found to be in the range of 5.92–26.73 mg TE/100 g, 4.88–15.03 mg TE/100 g, and 5.57–14.69 mg GAE/100 g, respectively. There were no statistically differences between control and HM-added groups in terms of lactic acid bacteria (LAB) counts, also in all samples the total LAB count was above 6 Log cfu/g during the storage. Fe, Mn, B, and Ba mineral values of samples with HM were higher than control sample. Cd, As, Hg and Li heavy metals were not detected in any of the samples, consequently results were within reliable limits reported by JECFA (Joint FAO/WHO Expert Committee on Food Additives) and Turkish Food Codex. As a result of the sensory evaluation, the samples containing 20% HM generally received higher scores than the samples containing 15% HM. Considering all the parameters, it was concluded that HM yogurts can be used as a different type in the functional yogurt industry due to its pleasant and characteristic taste.
AtıfScopus44WoS39OpenAlex51İncele - MakaleYalnız künye2021Scopus SJRQ2Vitamin, mineral, polyphenol, amino acid profile of bee pollen from Rhododendron ponticum (source of “mad honey”): nutritional and palynological approach
Ecem Bayram, Nesrin
In this study, it was aimed to characterize the pollen collected by bees from the Rhododenron ponticum plant, which is the source of mad honey, in terms of some parameters. In the first stage, the botanical origin of the sample was confirmed by palynological analysis supported by light microscopic images. Then, the chemical profile of Rhododenron ponticum bee pollen was examined in terms of 31 elements, 42 amino acids, 33 phenolics and vitamins A, B1, B2, B5, B6, B7, B12, C, E, K1 and K2. The total individual phenolic compound content of Rhododendron ponticum bee pollen was determined as 11928.23 µg/100 g, total element content as 13997.75 mg/kg, total free amino acid content as 149466.11 µg/g and total vitamin content as 20509.37 µg/100 g. In addition, it was characterized by a low content of vitamin A (retinol), B7, B12, K2, as well as a deficiency of vitamin K1. As a result of analysis with LC-MS-MS, it was found that it contains L-asparagine and myricetin in a significantly higher concentration compared to other amino acids and phenolic compounds. However, the presence of phenolic compounds (myricetin, epicatechin, tyrosol etc.) and amino acids (L-asparagine, gamma-aminobutyric acid, L- Tryptophan etc.) with significant biological activity indicates that this product is a bee product with high medicinal properties. Moreover, the significant presence of Mg, P, Fe and Ca, high K/Na ratio, vitamin C, B2, B5 and B6 content makes bee pollen collected from Rhododendron ponticum plant attractive for diets.
AtıfScopus36WoS27OpenAlex36İncele