Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(47)
- Pat, Suat(29)
- Özen, Soner(29)
- Şenay, Volkan(24)
- Korkmaz, Şadan(23)
- Esmer, Yusuf(21)
- Şahin, Engin(21)
- Korkmaz, Özge(20)
- Cuce, Erdem(19)
- Öner, Erdal(18)
- Öztürk, Mesut(18)
- Artar, Musa(17)
- Yilmaz, Mustafa Tahsin(17)
- İspirli, Hümeyra(16)
- Ecem Bayram, Nesrin(15)
- Kaya, Yunus(15)
- Cinar, Mehmet(13)
- Cuce, Pinar Mert(12)
- Kamiloğlu, Aybike(12)
- Kutlu, Naciye(12)
- Mercan, Emin(12)
- Birinci, Ahmet(11)
- Bulut, Mehmet(11)
- Yaylacı, Murat(11)
- Bayram, Ozkan(10)
- Can, Zehra(10)
- Doğan, Zeki(10)
- Kahya, Cem(10)
- Karaali, Rabi(10)
- Pabuçcu, Hakan(10)
- Tosun, Figen Çam(10)
- Özdemir, Akın(10)
- Ayazoglu, Rabil(9)
- Battal, Fetullah(9)
- Bayram, Nesrin Ecem(9)
- Büte, Mustafa(9)
- Ertugrul, Mehmet(9)
- Kadakal, Mahir(9)
- Kaplan, Abdullah(9)
- Sarikaya, İsmail(9)
Yayınlar
- MakaleYalnız künye2021Scopus SJRQ1Production of lactose derivative hetero-oligosaccharides from whey by glucansucrase E81 and determination of prebiotic functions
İspirli, Hümeyra; Dertli, Enes
Bioactive oligosaccharides are important compounds for development of functional foods and ingredients. In this study, lactose derivative hetero-oligosaccharides were produced by acceptor reaction of glucansucrase E81 with whey. The synthesis of oligosaccharides was monitored by Thin Layer Chromatography (TLC) analysis followed by 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopy analysis which demonstrated the glycosylation of lactose with α-(1 → 2), α-(1 → 3) and α-(1 → 4) linkages. Liquid chromatography–mass spectrometry (LC-MS) analysis demonstrated the formation of DP 7 oligosaccharides from whey. The synthesized oligosaccharides were not digested under in vitro human gastric juice and α-amylase conditions. The prebiotic effect of lactose derivative hetero-oligosaccharides was tested and no growth in pathogenic strains was observed whereas certain probiotic strains utilised lactose derivative hetero-oligosaccharides as Carbon source and their growth was promoted. These findings can be important to reveal the potential of glucansucrases to produce functional oligosaccharides from different sources including waste materials.
AtıfScopus17WoS16OpenAlex16
İncele - MakaleYayıncıda açık erişim2021Scopus SJRQ2Determination of flexural properties of hybrid composite using Cowper-Symonds rate-dependent material model
Erbayrak, Engin
This study addressed to determine the flexural properties of hybrid composite laminates (HCAFRE) under the strain rate sensitivity. The hybrid composite laminate was formed as consecutive stacking of a sequence of plain woven carbon fiber reinforced epoxy (CFRE) and a plain-woven aramid fiber reinforced epoxy (AFRE) laminates. The flexural tests were carried out at four different strain rates (0.01, 0.11, 0.55, 1.1 s−1) to determine the strain rate sensitivity of the HCAFRE. Moreover, the strain rate sensitivity of CFRE and AFRE was also determined individually. The effect of different fiber orientations (0°, 45°, and 90°) on the flexural properties of the composite laminates were also investigated at the scope of this study. In numerical analysis, composite laminates (CFRE, AFRE, and HCAFRE) were constituted in LS-DYNA finite element program using the Cowper-Symonds material model (MAT 112) which includes strain rate dependency. Consequently, it was seen that the experimental and numerical results were indicated a similar tendency to each other. Therefore, it was understood that the Cowper-Symonds material model is suited for the flexural behavior model of composite laminates under different strain rates.
AtıfScopus8WoS6OpenAlex8İncele - MakaleYalnız künye2021Scopus SJRQ2Determination of mechanical properties of polymer matrix composites reinforced with electrospinning N66, PAN, PVA and PVC nanofibers: A comparative study
Uslu, Emin; Gavgali, Mehmet; Erdal, Mehmet Okan; Yazman, Şakir; Gemi, Lokman
Fiber-reinforced polymer matrix composites are widely used in many structural applications thanks to their exceptional properties. In recent years, the use of electrospinning nanofibers with unique properties as reinforcement agents has attracted a great deal of attention in improving the performance of these composites. Although there are many promising studies on this subject in the literature, there are still many issues that need to be investigated. In this study, an experimental research reporting on the production and mechanical properties of two-phase polymer matrix composites reinforced with various types of thermoplastic nanofibers is presented. Nanofiber mats were produced from N66, PAN, PVA, and PVC polymers by electrospinning technique. Composites were obtained by embedding these nanofibers into epoxy resin by using vacuum infusion process. Mechanical properties of the composites were determined by performing tensile tests and the results were compared. The morphologies of nanofibers and the fracture surfaces of the composites were examined with SEM. Finally, statistical evaluations were carried out using mechanical data. According to tensile test results, the best ultimate tensile strength of 38.04 ± 3.7 MPa, elongation of 2.46 ± 0.4 % and toughness of 532 ± 137 kJ/m3 were obtained from N66 nanofiber composite, while PVA nanofiber composite was the most favorable in terms of Young's modulus (2.40 GPa). It was observed that the polymer type significantly affected the performance of the composite. In addition to the best mechanical properties, N66 composite was found to be more stable and reproducible than other specimens. Due to the good impregnation of nanofibers, it was conclusively determined that the use of vacuum infusion process is suitable for the production of these materials.
AtıfScopus79WoS73OpenAlex81İncele - Kitap BölümüYalnız künye2021Analyzing financial performance of paper products, printing and publishing companies traded at BIST via fuzzy TOPSIS methodology
Çelik, Pelin
- MakaleYalnız künye2021Scopus SJRQ2Characterization of physicochemical and antioxidant properties of Bayburt honey from the North-east part of Turkey
Bayram, Nesrin Ecem; Kara, Hasan Hüseyin; Can, Aslı Muslu; Bozkurt, Fatih; Akman, Perihan Kübra; Vardar, Sevgi Umay; Çebi, Nur; Yılmaz, Mustafa Tahsin; Sağdıç, Osman; Dertli, Enes
The aim of this study was to determine the physicochemical properties, bioactive substance content, and microbiological quality of sixty different honey samples collected from twelve different regions of Bayburt, Turkey. The samples were analyzed for their sugar, moisture, total phenolic, total flavonoid contents, and water activity, conductivity, pH values and colour, antiradical activity, and DSC properties. As a result of physicochemical analyses, it was determined that the samples examined complied with the standard values defined in the Turkish Food Codex in terms of the parameters examined. The results of the study showed that the total phenolic content (219.43-768.82 mg GAE kg−1), total flavonoid content (31.29-118.7 mg CAE kg−1) and DPPH (12.98%-94.79%) parameters differ widely among the honey samples. A principal component analysis (PCA) was applied to correlate the characteristics of honey with honey samples collected from different regions. This is the first comprehensive and original report about the physicochemical properties of honey produced in Bayburt, a region close to the Anzer region where the most expensive honey, Anzer honey, is produced.
AtıfScopus19WoS17OpenAlex23İncele - MakaleYalnız künye2021Scopus SJRQ2Asymmetric reduction of aromatic heterocyclic ketones with bio-based catalyst Lactobacillus kefiri P2
Baydaş, Yasemin; Kalay, Erbay; Şahin, Engin
Abstract: Chiral heterocyclic secondary alcohols have received much attention due to their widespread use in pharmaceutical intermediates. In this study, Lactobacillus kefiri P2 biocatalysts isolated from traditional dairy products, were used to catalyze the asymmetric reduction of prochiral ketones to chiral secondary alcohols. Secondary chiral carbinols were obtained by asymmetric bioreduction of different prochiral substrates with results up to > 99% enantiomeric excess (ee). (R)-1-(benzofuran-2-yl)ethanol 5a, which can be used in the synthesis of pharmaceuticals such as bufuralols potent nonselective β-blockers antagonists, Amiodarone (cardiac anti-arrhythmic), and Benziodarone (coronary vasodilator), was produced in gram-scale, high yield and enantiomerically pure form using L. kefiri P2 biocatalysts. The gram-scale production was carried out, and 9.70 g of (R)-5a in enantiomerically pure form was obtained in 96% yield. Also, production of (R)-5a in terms of yield and gram scale through catalytic asymmetric reduction using the biocatalyst was the highest report so far. This is a cost-effective, clean and eco-friendly process for the preparation of chiral secondary alcohols compared to chemical processes. From an environmental and economic perspective, this biocatalytic method has great application potential, making it a green and sustainable way of synthesis. Graphical Abstract: [Figure not available: see fulltext.]
AtıfScopus8WoS8OpenAlex9İncele - Kitap BölümüYalnız künye2021Socioeconomic Analyses on Covid-19, Underdevelopment, and Inequalities
Gültekın, Ömer Faruk
- MakaleYalnız künye2021Scopus SJRQ1Exploring Self-Regulation Skills in the Context of Peer Assisted Writing: Primary School Students’ Sample
Sarikaya, İsmail; Yılar, Ömer
The purpose of this research is to determine the self-regulation behaviors demonstrated by the 4th grade students in the writing process within the scope of peer-assisted writing activities. The aims of this research include developing a measurement tool to identify the self-regulation behaviors exhibited by primary school students during the writing process. The study was designed in accordance with the qualitative research approach. The data were acquired through observation and video recordings. The study was carried out with 4th grade students in primary school and conducted in two stages as a pilot and main study. The pilot application was carried out with six students. The main study was carried out in two different 4th graders with 30 students. A cluster random sampling method was used to determine the research group. In order to determine the self-regulation behaviors demonstrated by students during the writing process, a semi-structured observation form was used. Expert opinions were taken for the validity and reliability of the created form. The data were subjected to descriptive and content analysis. As a result of the study, some self-regulation behaviors were determined that demonstrated by 4th grade students. These behaviors are presented under seven topics: regulation of environmental factors, regulation of sensory and motivational factors, planning, strategy development, regulation of temporal and social factors, monitoring, and evaluation.
AtıfScopus4WoS5OpenAlex8İncele - Kitap BölümüYalnız künye2021Covid-19 Impact on Global Supply Chains
Güleryüz, Didem
- MakaleYalnız künye2021Comparison of kinetics of Cr (III) ions removal from wastewater using raw and activated montmorillonite minerals
İrdemez, Şahset; Durmuş, Gül; Kul, Sinan; Torun, Fatma Ekmekyapar; Bingül, Züleyha
In this study, kinetics of the removal of Cr (III) from the waters by adsorption have been investigated using montmorillonite natural clay that was obtained from the vicinity of Narman, Erzurum in Turkey. Activation energy, thermodynamic values and adsorption kinetics were determined. In addition, the trials were repeated by subjecting to the same adsorbent activation process. The values found for these two adsorbents were compared. As a result of the experiments, the parameters affecting the adsorption kinetics were examined. It was determined that the adsorption process could be best depicted by pseudo second order reaction kinetics. Using pseudo second order reaction rate constants, ΔH° =-25.791 kJ mol-1 and ΔS° = 106.19 joule mol-1 were calculated for raw adsorbent. For the activated adsorbent, ΔH° =-18,806 kJ mol-1 and ΔS° = 79.37 joule mol-1 were calculated. That ΔG° increases as temperature increases indicates; adsorption is more spontaneous at high temperatures. Negative ΔH° values show that the reaction is exothermic. The positive values of ΔS° indicate increased randomness at the adsorbent/solution interface during the adsorption of chrome.
AtıfScopus2WoS1OpenAlex3İncele - MakaleYalnız künye2021Scopus SJRQ2Frozen image analysis of a superconducting magnetic levitation system consisting of multi-surface superconductor and Halbach array permanent magnet configuration
Cansiz, Ahmet; Reisoglu, Ahmet F.; Ozturk, Kemal; Abdioglu, Murat
Levitation strength provided by high temperature superconductors are limited for device applications. Although superconducting material properties are continuously improving, there is still strong necessity of efficient design mechanisms for the superconducting magnetic levitation systems. Studies in the last decades have shown that combining multi-surface superconductor and permanent magnet components in optimum configurations has improved the levitation forces. In this respect, Halbach arraying permanent magnets interacting with multi-surface superconductors has become one of the most utilized methods. This paper investigates frozen image modeling of the levitation and guidance forces on a particular levitation system, which consists of a permanent magnet guideway and high temperature superconductor car body. The levitation enhancement is investigated for three configurations according to force interactions between the guideway and car body. These configurations are based on the use of single permanent magnet-single superconductor, Halbach array permanent magnets-single superconductor and Halbach array permanent magnets-multi-surface superconductors. The vertical and guidance forces for the present configurations were calculated in terms of field cooling and zero field cooling conditions by using frozen image model with magnetic dipole approximation. The predicted force calculations are analyzed in terms of vertical and lateral traverses of the car body respect to guideway for particular measurement distances. The force analysis provided by frozen image model qualitatively agree with the previously obtained experimental data.
AtıfScopus8WoS9OpenAlex9İncele - MakaleYalnız künye2021SOME NEW INEQUALITIES FOR (α, m1, m2)-GG CONVEX FUNCTIONS VIA GAMMA AND INCOMPLETE GAMMA FUNCTIONS
Kadakal, Mahir
In this study, we introduced the concept of (α, m1, m2)-GG convex functions; then we obtained Hermite-Hadamard type inequalities for these type of function classes via gamma and incomplete gamma functions together with Hölder, power-mean, Hölder-İşcan and improved power-mean integral inequalities.
- MakaleYalnız künye2021Scopus SJRQ4Investigating the role of social functions of parks on adherence to physical activity of elderly people during an epidemic disease (COVID-19)
Azimkhani, Amin; Honari, Habib; Türkmen, Mutlu; Gholamian, Javad; Saatchian, Vahid; Salari, Reyhane
Introduction: The importance of desirable physical activity as a deterrent and risk factor for the elderly is well known. The present study was conducted to investigate the role of parks’ social functions on adherence to physical activity in elderly people in Mashhad During epidemic disease (COVID-19). Method: This cross-sectional study was performed using a structured interview technique and a multi-part questionnaire on 100 elderly people. Sampling was done in two stages using a systematic random method. Results: Based on the results, it was found that there is a positive and significant relationship between the social function of parks and its components with adherence to physical activity in the elderly (P <0.05) and well as 18% of adherence to physical activity changes is related to the social function of parks. Conclusion: The findings of this study showed that many factors are affecting physical activity in elderly people, which understanding these factors help educators and other health professionals in designing appropriate intervention programs. Maintaining regular PA during self-isolation is important for the prevention of future chronic health conditions due to a sedentary lifestyle. During crises, functional medical care and vital societal services are of the highest priority.
AtıfScopus1OpenAlex1İncele - MakaleYalnız künye2021Scopus SJRQ1A regional supplementary cementitious material for the cement industry: Pistachio shell ash
Tekin, İ.; Dirikolu, İ.; Gökçe, H.S.
The recycling of agricultural wastes in cementitious products has recently been a trendy approach for the sustainability goals of the world as it ensures economic and ecological advantages in addition to the safe disposal of these wastes. In this regard, the potentiality of a biomass ash obtained from the incineration of pistachio shell to serve as a supplementary cementitious material is documented in the present study. An increase of up to 30% in the amount of pistachio shell ash resulted in the proportional increase of both water requirement and setting time of the ordinary Portland cement by up to 54% and 300%, respectively. The incorporation of up to 20% pistachio shell ash into the cement yielded specimens of comparable or higher compressive strength values relatively varying between 98% and 117% at the 28 days and later curing ages. Beside the cementitious property, it was observed that a presence of graphitic structures in the pistachio shell ash remarkably improved the mechanical and the microstructural properties of cement mortars. In conclusion, at least 10% incorporation of this ash into the cement is highly recommended for the cement industry as it is beneficial in achieving the highest ultimate (400-day) compressive strength and promotes no loss on the early (2-day) compressive strength.
AtıfScopus41WoS38OpenAlex45İncele - MakaleYalnız künye2021Scopus SJRQ1Graphical Method for Examining Complex Natural Frequencies of Dispersive Materials
Hasar, Ugur C.; Ozturk, Gokhan; Barroso, Joaquim J.; Gurbuz, Tolga U.; Kaya, Yunus; Ertugrul, Mehmet
A graphical method is extended to and applied for visual inspection of solution patterns (region of complex natural frequencies sₙ) in the complexs-plane for dispersive materials characterized by the Debye and Lorentz models. These patterns are in the form of exponential decay and C-shaped profiles for the Debye and Lorentz models, respectively. Their forms are observed to be affected (e.g., moving left/right) in different manners with a variation of dispersion parameters. This method, thanks to its visual inspection capability, can help in analyzing/synthesizing filters and frequency-selective surfaces.
AtıfScopus6WoS6OpenAlex7İncele - Kitap BölümüYalnız künye2021Smart Cities, Covid 19, and the Future of the Cities
Sengün, Hayriye
- MakaleYalnız künye2021Scopus SJRQ1QoSChain: Provisioning Inter-AS QoS in Software-Defined Networks with Blockchain
Karakus, Murat; Guler, Evrim; Uludag, Suleyman
Data flows of various applications, such as video conferencing, telesurgery, online-gaming, etc., require particular treatment regarding Quality of Service (QoS) because of their sensitivity to such parameters as high bandwidth, low delay, and so on. However, provisioning of QoS-based routing services across Autonomous Systems (ASes) poses gruelling challenges due to the distributed nature and business confidentially hesitations. This study presents a novel blockchain-aided QoS-enabled inter-AS routing framework, QoSChain (QC), by blending merits of Software-Defined Networking (SDN) and Blockchain technologies. QC framework introduces a coordination framework with mutually distrusting participants that eliminates centralized mediators in provisioning QoS among SDN-enabled ASes. Also, QC reduces the time to set up an end-to-end (E2E) path and the number of messages exchanged and processed by SDN controllers for a QoS flow. Furthermore, it alleviates the concerns of network operators regarding potentially sensitive information disclosure resulting from the required information sharing for QoS-based cross-AS paths by masking details of any confidential information. Experimental results verify the feasibility of the proposed framework on E2E QoS-based routing among SDN networks. This work aims at being a useful primer for researchers in providing insights on how blockchain can be deployed in QoS-enabled routing.
AtıfScopus32WoS21OpenAlex30İncele - Derleme MakaleYalnız künye2021Scopus SJRQ4The effect of muscle electrical stimulation on muscle stiffness problems and musculoskeletal pain caused by muscle imbalance: A systematic review
Saatchian, Vahid; Türkmen, Mutlu; Esfahani, Mahdi; Zadeh, Reza Amin; Talib, Ahmed Mushtaq; Azimkhani, Amin
Whole Body Electrical Stimulation (WB-EMS) is a relatively new training method that has been used extensively in recent years, however, the lack of consensus on the efficacy of Whole Body Electrical Stimulation exists, and the aim of this study is to investigate the effects of this method on postural structure problems and musculoskeletal pain. Summary of articles by ISC, Google Scholar, American Journal of Sports Medicine, PubMed Journal of Rehabilitation Medicine, Cochrane, and Sports Medicine Journals between 2000 and 2019 were studied to identify all studies that report electrical stimulation applied simultaneously to the upper and lower limbs. Keywords: Electrical stimulation, Electrical muscle stimulation, Functional electrical stimulation, Whole body electrical stimulation, Wearable sensors, Electrotherapy, Electrode vest, Electrode vest for treatment and rehabilitation, E-fit, Electronic muscle stimulation, Whole body electronic muscle stimulation, Electronic Stimulation, Electronic Suit, Wearable Sensor, and Electrotherapy were used to obtain relevant articles and finally, 22 articles were compared according to the set criteria of 107 papers. Based on the results of studies on the effects of Whole Body Electrical Stimulation, this tool is based on parameters such as muscle strength, muscle size, body composition, obesity, sarcopenia, sarcopenia- induced obesity and pain reduction in non-specific chronic low back pain patients, have a significant positive effect. Due to the lack of studies on the effects of Whole Body Electrical Stimulation and the inconsistency between studies and the lack of similar consensus, further research is needed.
AtıfScopus4WoS3İncele - MakaleYalnız künye2021Scopus SJRQ1The effects of fuel type onto the structural, morphological, magnetic and photocatalytic properties of nanoparticles in the synthesis of cobalt ferrite nanoparticles with microwave assisted combustion method
Karakas, İbrahim Hakkı
In this experimental study, the synthesis of cobalt ferrite nanoparticles, one of the most important types of ferromagnetic spinel ferrite materials was realized by using a method known as microwave assisted combustion method. The effects of the substance used as fuel on the structural, morphological, magnetic and photocatalytic properties of synthesized nanoparticles were investigated. Firstly, samples were prepared using urea, glycine and citric acid as fuel and then the samples were comprehensively characterized by advanced analysis techniques such as XRD, FT-IR, TEM, SEM, VSM, BET. Moreover, the usability of the obtained nanoparticles in photocatalytic degradation process of Procion Yellow H-E3G textile dye as photocatalyst was investigated. The results obtained indicate that the fuel used is highly effective on various properties of the synthesized materials. From the experiments performed to evaluate the photocatalytic performances of the nanoparticles, it was observed that each of the three different fuel matters used for the synthesis of nanoparticles were highly effective on the photocatalytic degradation of the organic pollutant. Furthermore, almost all the dye content in solution was completely removed at the end of the experimental period which lasted for 90 min.
AtıfScopus50WoS44OpenAlex51İncele - MakaleYalnız künye2021Scopus SJRQ1Physical, mechanical, and radiation attenuation properties of serpentine concrete containing boric acid
Zayed, A.M.; Masoud, M.A.; Shahien, M.G.; Gökçe, H.S.; Sakr, K.; Kansouh, W.A.; El-Khayatt, A.M.
Serpentine and boric acid are effective materials to produce the radiation-shielding concrete (RSC) for attenuating the fast and thermal neutrons, respectively. Therefore, this study investigates the effect of boric acid (0, 1, and 3% by cement weight) on the physical, mechanical, microstructural, and radiation shielding properties of serpentine concrete. The results showed that the addition of boric acid hindered the hydration of cement through the generation of amorphous borate material, which encapsulates the cement phases and retards their transformation into hydration products. Such a retardation process negatively influenced the mechanical properties of boric acid-bearing concrete and contributed to the thicker and less condensed interfacial transition zone. Furthermore, unlike total γ-rays, boric acid enhanced the attenuation properties of serpentine concrete against thermal and fast neutrons favoring the former. There was a satisfying agreement between the theoretical and measured values of fast neutron attenuation parameters. However, negligible variations in the theoretical values of photon interaction parameters showed that porosity was the principal reason for the reduction in gamma-ray attenuation as a result of boric acid addition.
AtıfScopus91WoS88OpenAlex93İncele