Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(115)
- Kaya, Yunus(50)
- Ayata, Ümit(48)
- Şahin, Engin(48)
- İspirli, Hümeyra(46)
- Bayraktar, Bülent(42)
- Şenay, Volkan(41)
- Can, Zehra(39)
- Özen, Soner(37)
- Bayram, Sinan(35)
- Pat, Suat(35)
- Öztürk, Mesut(35)
- Ecem Bayram, Nesrin(34)
- Esmer, Yusuf(34)
- Battal, Fetullah(33)
- Artar, Musa(32)
- Öner, Erdal(32)
- Korkmaz, Şadan(31)
- Yilmaz, Mustafa Tahsin(31)
- Ertugrul, Mehmet(30)
- Mercan, Emin(30)
- Hasar, Ugur Cem(29)
- Kutlu, Naciye(28)
- Özdemir, Akın(27)
- Kul, Murat(26)
- Cuce, Erdem(25)
- Kamiloğlu, Aybike(25)
- Bayram, Ozkan(24)
- Sefali, Abdurrahman(24)
- Sert, Durmuş(24)
- Çolak, Murat(24)
- Ayazoglu, Rabil(22)
- Gıdık, Betül(22)
- Maden, Sedat(22)
- Ustabulut, Mete Yusuf(22)
- Uçurum, Metin(22)
- Akeren, Zahide(21)
- Dirican, Ebubekir(21)
- Kara, Yakup(21)
- Abdioglu, Murat(20)
Yayınlar
- MakaleYalnız künye2023Exergetic Analyses of Hypersonic Flows
Topal, Esra Nur; Karaali, Rabi
Hypersonic devices and vehicles and hypersonic flows are very important and competitive advanced technology in science and in the World. Hypersonic technology is rapidly spreading and turning into competition in developed countries, especially in space studies and defense industry. This technology is vital for developed countries. Because of shock waves emerging in hypersonic devices during hypersonic flow, the energy and exergy destructions they cause are the most important difficulties, obstacles and problems which arise in this vital technology. To overcome these problems and difficulties, to prevent or reduce or minimize energy and exergy destruction, aerodynamic analysis and energy and exergy analysis methods are applied. The data and the results that can be guiding and useful for the calculations and the design have been obtained. In this study optimal design and optimum calculations ways of the energy and exergy destructions of hypersonic devices and instruments are discussed. It is obtained and shown that how much exergy destruction and entropy production occurs at which altitude and hypersonic velocities and also at which oblique shock angles.
AtıfScopus2
İncele - MakaleAçık Erişim2023Scopus SJRQ2The Effect of Different Drying Methods on Bioactive and Nutrition Contents of Bee Bread and Mathematical Modeling of Drying Characteristics
Kutlu, Naciye; Gercek, Yusuf Can; Bayram, Nesrin Ecem
In this study, the aim was to determine the effect of different drying methods (with microwave and hot air) on the color, nutrient and bioactive contents of fresh bee bread. Drying characteristics were also investigated. Microwave and hot air drying were applied at different microwave powers and temperatures, respectively. Lower moisture ratios and highest effective diffusion coefficients were obtained with microwave drying in a shorter time. The Midilli model was found to be the most suitable thin-layer drying model for both methods. Regardless of the drying conditions, moisture, ash, protein, carbohydrate, and lipid proportions were observed to vary in the ranges of 4.9–8.2 %, 1.61–2.67 %, 17.47–32.54 %, 39.92–60.84 %, and 7.10–8.89 %, respectively. The lowest color difference was obtained for the sample dried at 210 W. As a result, it was determined that microwave drying is more suitable for preserving the nutritional and bioactive content of bee bread during drying.
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İncele - MakaleAçık Erişim2023Scopus SJRQ3Investigation of Use of Linden (Tilia tomentosa Moench.) Wood with UV System Varnish Application IN INDOOR Parquet Flooring
Ayata, Ümit; Esteves, Bruno; Domingos, Idalina; Ferreira, José; Tuncay Efe, Fatih; Türk, Mutlu; Çakicier, Nevzat; Gürleyen, Levent; Peker, Hüseyin
Linden wood is used in the making of musical instruments, agricultural hand tools, and in the furniture sector. In this study, the changes in glossiness (parallel (//) and perpendicular (⊥) to the fibers at 20°, 60°, and 85°, the pull-off adhesion test, color parameters (CIEL) and pendulum hardness (König method) of two different UV curable varnishes applied to linden (Tilia tomentosa Moench.) according to industrial application techniques and exposed to artificial weathering were investigated. According to the research results, while L*, ΔH*, and h° decreased with increasing weathering time in both varnish layers, ΔC*, b*, ΔE*, a*, and C* rose. The pendulum hardness grew for Method B but dwindled for Method A. A decrease was found in the adhesion tests for both varnish methods after artificial weathering. The glossiness was generally reduced due to artificial weathering for all the angles and for both directions, with the exception of 85º in Method A. The variance analysis and homogeneity groups showed that the changes in the adhesion, pendulum hardness, L*, a*, h°, C*, perpendicular and parallel to the fibers for 60° and 85° were found to be significantly different with artificial weathering for both methods.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2023Scopus SJRQ1Attitudes pregnant women in Türkiye towards holistic complementary and alternative medicine and influencing factors: a web-based cross-sectional study
Küçükkaya, Burcu; Işık, Hafsa Kübra
Background: Pregnant women turn to holistic complementary and alternative medicine to cope with problems associated with the changes they experience during pregnancy. This study aimed to determine the attitudes of pregnant women in Türkiye toward holistic complementary and alternative medicine and influencing factors. Methods: This cross-sectional exploratory study was carried out between June and November 2022 with a web-based questionnaire distributed via social media and communication platforms. Two hundred and twenty-one pregnant women participated in the study. A "Participant Identification Form" and the "Attitudes towards Holistic Complementary and Alternative Medicine Questionnaire" were used to collect the data. Logistic regression analysis was used to determine correlations between variables and scale scores. Results: It was determined that 84.2% of the participants had knowledge about traditional and complementary therapies, and 77.8% used traditional and complementary therapies. The participants reported that they preferred faith (77.4%), energy healing (76.9%), massage (75.6%), diet (74.2%), meditation/yoga (62.0%), and herbal (59.7%) traditional and complementary therapies the most, and most of them used these methods to reduce nausea, vomiting, edema, and fatigue during pregnancy. The mean Attitudes towards Holistic Complementary and Alternative Medicine Questionnaire score of the participants was 35.0 (5.04). It was seen that having high school or higher education (p < 0.05), having an income more than expenses (p < 0.001), having received advice from nurses when having a complaint (p < 0.001), having knowledge about traditional and complementary therapies (p < 0.001), and being a practitioner who received services of traditional and complementary therapies (p < 0.001) were positively associated with the utilization of traditional and complementary therapies. Conclusion: In this study, it was determined that the attitudes of pregnant women towards holistic complementary and alternative medicine were high. Their personal characteristics, as well as their knowledge and practice of holistic complementary and alternative medicine affected their attitudes towards holistic complementary and alternative medicine. Obstetrics nurses/midwives should actively participate in training programs on traditional and complementary therapies focused on pregnant women.
AtıfScopus10WoS5OpenAlex9İncele - MakaleYalnız künye2023Scopus SJRQ3Comparison of the critical power estimated by the best fit method and the maximal lactate steady state; [Comparaison entre la puissance critique estimée par la méthode bien-être et l’état d’équilibre maximal du lactate]
As, H.; Cabuk, R.; Norouzi, M.; Balci, G.A.; Ozkaya, O.
Aims: Maximal lactate steady state (MLSS) is accepted as the gold standard method to determine the upper boundary of heavy exercise domain, while critical power (CP) is one of the most practical ways to estimate the lower boundary of severe exercise domain. However, it has been recently discussed that the upper boundary of heavy-intensity exercise domain does not equal to lower boundary of severe-intensity exercise domain. Conversely, the best individual fit method (CPfit) has recently been suggested as an accurate estimation of CP. However, there has not been a comparative evaluation of CPfit versus MLSS. The aim of this study was, therefore, to focus on the comparison of CPfit with MLSS. Methods: Eleven well-trained male cyclists participated in this study. Following the determination of maximal oxygen uptake, MLSS was determined through the performance of standard 30-minute constant work rate exercises performed on separate days. Cyclists performed four constant-load exercises lasting 2–15 minutes on different days. The data were then fitted to mathematical models to obtain CPfit. Bland-Altman plot with 95% limits of agreement (LoA) was used to measure agreement between CPfit and MLSS. Results: According to the findings, CPfit overestimated the work rate corresponding to MLSS (300 ± 38 W vs. 265 ± 39 W; P = 0.001; effect size = 3.28). Bland-Altman results showed high LoA (14 to 55.9 W) and very high bias (bias = 35 ± 10.7 W; P = 0.001; r: 0.96) between CPfit and MLSS. Conclusion: CPfit was not identical for MLSS.
AtıfScopus1WoS2OpenAlex3İncele - MakaleYalnız künye2023Scopus SJRQ1Comparison of bioactive constituents by HPLC–DAD–ESI-MS and UFLC and in vitro antioxidant activities of blossom honey, bee pollen, and propolis
Saroğlu, Öznur; Ecem Bayram, Nesrin; Özçelik, Beraat
The aim of this study was to analyze the total phenolic content, phenolic profile, and antioxidant activity of honey, bee pollen, and propolis samples from Turkey's Black Sea Region. The total phenolic content of these bee products was found using Folin–Ciocalteu's method, and their antioxidant capacity was found using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and cupric ion reducing antioxidant capacity (CUPRAC) assays. Phenolic compounds of honey samples were characterized by high-performance liquid chromatography coupled to a photodiode array detector and mass spectrometer (HPLC–DAD–ESI-MS), while phenolic compounds of bee pollen and propolis samples were quantified ultra-fast liquid chromatography (UFLC). The total phenolic values for honey, bee pollen and propolis were 6.32–18.21 mg GAE/100 g, 547.64–769.4 mg GAE/100 gr, and 6096.1–11,564 mg GAE/100 gr, respectively. DPPH and CUPRAC values of honey, pollen and propolis were 11.05–21.38% and 0.38–1.48 µmol Trolox/g; 24.67–38.63% and 0.03–0.05 mmol Trolox/g; 11.81–34.12% and 0.47–0.89 mmol Trolox/g, respectively. About 30 different phenolic compounds were identified as quantitative. Our findings have shown that all bee products examined in the study are found to contain gallic acid, naringenin, and caffeic acid. In terms of total phenolic content and antioxidant activity, the bee product extracts were ranked as follows: propolis > bee pollen > honey. The high concentration of phenolic compounds in propolis explains its remarkable antioxidant effect.
AtıfScopus10WoS10OpenAlex10İncele - MakaleAçık Erişim2023Scopus SJRQ1Investigation of student experiences with ChatGPT-supported online learning applications in higher education
Kayalı, Bünyami; Yavuz, Mehmet; Balat, Şener; Çalışan, Mücahit
The purpose of this study was to determine university students' experiences with the use of ChatGPT in online courses. The sample consisted of 84 associate degree students from a state university in Turkey. A multi-method approach was used in the study. Although quantitative data were collected using the Chatbot Usability Scale, qualitative data were collected using a semi-structured interview form that we developed. The data were analysed using descriptive and content analysis methods. According to the findings, ChatGPT exhibits advantages such as a user-friendly interface and fast, concise, relevant responses. Moreover, emphasizing its contribution to the learning process, the information provided was sufficient and topic-oriented. The understandability of the chatbot’s functions and the clarity of their communication were emphasized. However, there are disadvantages such as performance issues, frequency of errors and the risk of providing misleading information. Concerns have also been raised about the potential difficulties chatbots may face in ambiguous conversations and providing insufficient information on privacy issues. In conclusion, ChatGPT is recognised as a potentially valuable tool in education based on positive usability impressions; however, more research is needed for its safe use. Implications for practice or policy • Based on positive usability impressions, students and instructors can use ChatGPT to support educational activities. • ChatGPT can promote and enhance students' personalised learning experiences. • ChatGPT can be used in all higher education courses. • Users should be cautious about the accuracy and reliability of the answers provided by ChatGPT. • Decision-makers should take precautions against risks such as privacy, ethics, confidentiality and security that may arise from using artificial intelligence in education.
AtıfScopus79WoS48OpenAlex76İncele - MakaleAçık Erişim2023Scopus SJRQ2Relation of ATPase6 Mutations and Telomere Length in Schizophrenia Patients
Uzuncakmak, Sevgi Karabulut; Dirican, Ebubekir; Ozcan, Halil; Takim, Ugur
Objective: Schizophrenia is a serious mental disorder. Mutations in mitochondrial genes can change energy metabolism. Telomere is a tandem sequence at the end of chromosomes. Shorter telomere length has been shown in schizophrenia. The aim of this study was to determine the relationship between ATPase6 gene mutations and telomere length in schizophrenia patients. Methods: Blood samples of 34 patients and 34 healthy controls were used. In this study conventional PCR, Sanger sequencing technic and real-time PCR were utilized. Results: Five different mutations (A8860G, A8836, G8697A, C8676T, and A8701G) in the ATPase6 gene were identified in schizophrenia patients. The most seen mutation was A8860G (94%). Telomere length analysis indicated the relation of ATPase6 gene mutations and telomere length variations (p = 0.001). Patients carrying the A8860G mutation had shorter telomere lengths than patients carrying other mutations. Comparing telomere length between schizophrenia patients and healthy controls revealed that the mean telomere length of schizophrenia patients was shorter than healthy controls (p = 0.006). The demographic analysis demonstrated a significant relationship between marital status and telomere length (p = 0.011). Besides that, the duration of the illness is another factor that impacts telomere length (p = 0.044). There is no significant relation between telomere length and other clinical and demographic characteristics including education status, age, gender, etc. Conclusion: In conclusion, telomere length and ATPase6 gene mutations have a significant relation. Studies with larger patient populations and investigation of other mitochondrial gene mutations will make the clearer link between telomere length and mitochondrial mutations.
AtıfScopus4WoS3OpenAlex4İncele - MakaleAçık Erişim2023Scopus SJRQ2Investigation of the effects of changes in formulation and cooking times on the quality parameters in the production of goji berry leather
Maraş, R. Talay; Erdoğan, U.
Goji berry (Lycium barbarum L.) is described as a food with several health benefits. This valuable fruit has been processed into fruit leather, which is one of the important traditional products. This study allowed us to determine the effect of changing formulations (starch and flour) and cooking times (10, 15, and 20 min) on quality criteria during goji berry leather production. The goji berry leather samples exhibited the following characteristics: pH values ranging from 4.96 to 4.99, titration acidity values spanning from 2.97% to 3.23%, dry matter content within the range of 84.78% to 87.69%, ash content between 3.12%, and 4.27%, water activity (aw) values ranging from 0.37 to 0.38, protein content between 14.71%, and 15.66%, HMF content varying from 17.33 mg/kg to 34.51 mg/kg, total phenolic content ranging from 7.14 µg GAE/g to 7.89 µg GAE/g, total sugar content falling between 61.18%, and 63.89%, reducing sugar content within the range of 60.13% to 61.89%, sucrose content ranging from 0.91% to 2.25%, thickness values ranging from 0.74 mm to 0.89 mm, hardness values varying between 17.09, and 33.27, stickiness values within the range of 4.10 to 23.34, cohesiveness values from 0.85 to 1.00, elasticity values ranging from 0.88 to 0.97, chewability values spanning from 12.85 to 30.85, L* values ranging from 27.27 to 32.66, a* values between 8.62, and 10.32, b*values varying from 7.06 to 8.59, C* values within the range of 11.15 to 12.81, and H° values falling between 39.31, and 41.13. Following the sensory evaluation of leather samples, it was determined that the color score ranged from 3.80 to 4.27, the smell score fell between 3.53 and 4.00, the taste score varied from 2.93 to 4.00, the mouthfeel score ranged from 2.93 to 3.93, and the general acceptability score was found to be within the range of 3.27 to 4.20. It was determined that cooking time and additional additives affect some quality values of the goji berry leather.
AtıfScopus1WoS1İncele - MakaleAçık Erişim2023Scopus SJRQ2Evaluation of IGFBP5 expression and plasma osteopontin level in COVID-19 patients
Karabulut Uzunçakmak, Sevgi; Aksakal, Alperen; Kerget, Ferhan; Aydın, Pelin; Halıcı, Zekai
Purpose: The aim of this study is to investigate insulin-like growth factor binding protein 5 (IGFBP5) expression in coronavirus disease 2019 (COVID-19) patients and its relationships with COVID-19 laboratory findings and plasma osteopontin (OPN) levels. Materials and methods: We enrolled 60 patients with COVID-19 and 30 healthy individuals in this study. mRNA expression of IGFBP5 was measured by RT-PCR. Plasma OPN levels were measured via the ELISA method. Results: Plasma OPN levels were higher and IGFBP5 expression levels were lower in COVID-19 patients than in the healthy individuals (p = 0.0057 and p = 0.0142, respectively). Critically ill patients had higher OPN and lower IGFBP5 than non-critically ill patients. Patients with affected lungs demonstrated increased OPN and decreased IGFBP5 (p = 0.00032 and p = 0.044, respectively). Receiver operating characteristic (ROC) analysis indicated that IGFBP5 expression and OPN levels can be used discriminate non-critically from critically ill patients (p = 0.049; p = 0.0016, respectively). Conclusion: This study demonstrated that patients with a poor prognosis had increased OPN and decreased IGFBP5. High values of OPN and low values of IGFBP5 may be considered as signs of disease severity. Tissue-specific IGFBP5 expression may contribute to understanding the role of IGFBP5 in the lungs in COVID-19 cases.
AtıfScopus6WoS6OpenAlex6İncele - MakaleYalnız künye2023Scopus SJRQ1Nectar honey from Turkey: crystallization and physicochemical profile
Ecem Bayram, Nesrin
Honey is a traditional food used by humans due to many therapeutic properties. Turkey is in a good position for the production of bee products, and honey is the most popular bee product in the country. In this study, the aim was to evaluate the quality parameters of 40 honey samples based on physicochemical parameters and to gain information about speed of crystallization. For this purpose, moisture (%), fructose (%), glucose (%), fructose + glucose (F + G, %), fructose/glucose (F/G), glucose/moisture (G/M), and proline (mg/kg) contents were determined in honey samples and cluster analysis was performed. When the sugar profile of honey samples is examined, F + G was 61.63–78.03%, F/G was 0.99–1.25, moisture content was 14.9–19.1%, and proline content was 384.41–1271.56 mg/kg. These results comply with national standards. Honey samples tend to crystallize quickly when their crystallization properties are evaluated based on F/G and G/M ratios. Consequently, the quality of honey differs according to the region from which it is produced and it is natural for honey to crystallize.
AtıfScopus4WoS3OpenAlex6İncele - MakaleAçık Erişim2023Performance Analyses of Combined Cycle Power Plants
Karaali, Rabi
In this article, different compressor pressure and different excess air rates for a gas turbine based combine cycle power plant with steam Rankine cycle as bottoming cycle were analyzed by using 1. and 2. laws of thermodynamics and exergy analyses methods to obtain the best performances of the cycle. Exergy efficiency of the cycle, net powers of the gas and steam turbines and the overall cycle, exergy loss of the components, the efficiencies of the components are obtained, compared and discussed. It was found that, increasing the compressor pressure increases exergy efficiency of cycle, gas turbine and total plant power, and the combustion chamber, the HRSG and the compressor efficiencies. However, increasing compression rates decreases steam turbine power, combustion chamber, steam turbine, and HRSG exergy losses and the gas turbine efficiency. Also, it is found that, increases in excess air ratios gives an optimum or a maximum exergy efficiency, at 2.5 excess air rate of the cycle.
AtıfScopus3OpenAlex6İncele - MakaleAçık Erişim2023Scopus SJRQ2Efficient production of acetone butanol ethanol from sole fresh and rotten potatoes by various Clostridium strains
Avcı, Ayşe; Kamiloğlu, Aybike; Dönmez, Sedat
This study aimed to evaluate rotten potato in the fermentation of acetone butanol ethanol (ABE). For this purpose, three strains, Clostridium acetobutylicum DSMZ 1731, Clostridium acetobutylicum DSMZ 6228, and Clostridium beijerinckii DSMZ 6422, were used and production experiments were performed in a simple media only composed of either fresh or rotten potato. Effects of potato concentration (100–400 g/L) and time (24–144 h) on the fermentation were determined using fresh potato. The highest ABE production was detected at 400 g/L potato concentration at the end of 96 h by all strains. Clostridium acetobutylicum DSMZ 6228 was the most efficient strain in producing ABE among the microorganisms tested. Total ABE productions by Clostridium acetobutylicum DSMZ 1731, Clostridium acetobutylicum DSMZ 6228, and Clostridium beijerinckii DSMZ 6422 at 400 g/L in 96 h were 12.3, 17.6, and 12.0 g/L, respectively. The majority of the products was butanol that made up ca. 66–67% of total ABE. Significant amounts of ABE were also produced with rotten potato which was compatible with the results obtained with fresh potato. They were determined as 11.5, 17.1, and 9.6 g/L with Clostridium acetobutylicum DSMZ 1731, Clostridium acetobutylicum DSMZ 6228, and Clostridium beijerinckii DSMZ 6422, respectively. The results showed that rotten potato could be a good candidate as substrate for ABE fermentation.
AtıfScopus18WoS16İncele - MakaleYalnız künye2023Scopus SJRQ2Optimization of microwave-assisted biosynthesis of silver nanoparticle with tarragon extract
Altuncu, Fatma Kübra; Kamiloğlu, Aybike
Response surface method was used to optimize microwave-assisted silver nanoparticle production with tarragon extract. As a result of the optimization study, tarragon silver nanoparticles (TAgNPs) were produced from 43 conditions with a degree of desirability of 1, with a processing time of 5.25 min, AgNO3 concentration of 9.89 mM, and tarragon extract concentration of 14.80%. Among the variable parameters, AgNO3 concentration affected TAgNP synthesis depending on processing time and tarragon extract concentration; tarragon extract concentration was found to significantly affect nanoparticle formation. TAgNP produced under optimum conditions was found to be crystalline, with a spherical surface morphology and an average particle size of 16.56 nm, with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction diffractometry (XRD) analyses. TAgNPs showed inhibitory effect for Escherichia coli BC 1402, Bacillus cereus BC 6830, Salmonella typhimurium RSSK 95091, Yersinia enterocolitica ATCC 27729, and Staphylococcus aureus ATCC 25923 microorganisms. The minimum inhibition concentrations were 10 µg/mL for B. cereus BC 6830, 50 µg/mL for E. coli BC 1402, S. typhimurium RSSK 95091, and Y. enterocolitica ATCC 27729, and 25 µg/mL for S. aureus ATCC 25923.
AtıfScopus2WoS2OpenAlex2İncele - MakaleYalnız künye2023REGULATORY EFFECT OF GENDER AND EDUCATION DEPARTMENT STATUS ON THE RELATIONSHIP BETWEEN INCLUSIVE EDUCATION AWARENESS AND SELF-EFFICACY
Taşyürek, Zeynep; Kodan, Hülya
Inclusive education is based on the idea that all individuals—regardless of individual characteristics and differences—should have access to education, a fundamental right granted to all. This study examines the relationship between pre-service teachers’ inclusive education awareness and self-efficacy and the impact of different variables that may affect this relationship. For this purpose, the Awareness Scale for Inclusive Education and the Teachers’ Self-Efficacy Perception of Inclusive Education Scale were used as data collection tools. The study was conducted through a correlational survey design to understand the relationship between pre-service teachers’ Awareness of Inclusive Education scores and Teacher’s Self-Efficacy Perception of Inclusive Education scores and determine the regulatory effect of gender and the departments in which the teachers studied on this relationship. The study sample included 360 pre-service teachers who completed the Special Education and Inclusion course. Data were analyzed using SPSS 24.0 and the Process Macro plugin. The results show a significant relationship between pre-service teachers’ awareness of inclusive education and self-efficacy perceptions. Results also indicate that while the regulatory effect of gender on the relationship between pre-service teachers’ inclusive education awareness and self-efficacy perceptions was not significant, the regulatory effect of the department they belonged to was substantial.
- MakaleAçık Erişim2023Scopus SJRQ2Effect of elevated temperature on radiation shielding properties of cement and geopolymer mortars including barite aggregate and colemanite powder
Kök, S.; Türetken, M.S.; Öksüzer, N.; Gökçe, H.S.
This study aims to investigate the radiation shielding efficiency of cement and geopolymer-based mortars after exposure to elevated temperatures which may happen during the activation process of nuclear reactors. To contribute to the shielding properties, these binders were modified with the substitution of colemanite powder (5 and 10%), and barite aggregate was used to be an alternative to silica sand, as well. The produced specimens were exposed to 300 and 500 °C. While the colemanite powder resulted in significant retardation of setting time up to 183% for cement-based series, a set accelerator effect reaching 67% was found in the geopolymer series. Unlike expectation, the losses in mechanical and shielding properties have become more pronounced in geopolymer mortars at the applied temperatures. In particular, a significant increase reaching 28% in compressive strength of cement series was found after 300 °C exposure. It was noted that cement series with reaching a linear attenuation coefficient of 0.162 cm−1 presented more effective shielding against gamma rays when compared to that (0.134 cm−1) of geopolymers. To moderate thermal neutrons, geopolymer series reaching a linear attenuation factor of 2.799 cm−1, were found to be a more promising alternative according to cement series reaching 2.140 cm−1.
AtıfScopus30WoS27İncele - MakaleAçık Erişim2023Scopus SJRQ3Comparison of Phenolic Profile and Antioxidant Properties of Pulp and Seeds of Two Different Grapes Types (Vitis vinifera L. and Vitis labrusca L.) Grown in Anatolia: The Amount of Resveratrol of Grape Samples
Kavgacı, Merve; Yukunc, Gulsah Okumus; Keskin, Merve; Can, Zehra; Kolaylı, Sevgi
Background: Grape is the most widely cultivated fruit all over the World and it is both food and a good source of antioxidants. The fruit is rich in phytochemicals and its seed is especially a source for resveratrol, a stilbene that shows health promoting effect. Objective: In this study, phenolic profile and antioxidant properties of eight grape cultivars with two species cultivated in Turkey were compared. Isabella, Razaki, Alphonse Lavalleé, Red Globe and Emir cultivars were used. Methods: Total phenolic substance (TPS), total flavonoid substance (TFS), total antioxidant capacity (FRAP) and phenolic compositions of the pulp and the seeds were determined. Phenolic composition of grapes were found by using HPLC-UV. Results: The results showed that total phenolic substances and total antioxidant capacities were richer in the seeds than in the pulps. Catechin and epicatechin are major phenolic compounds in the grape seeds, and chrysin, pinocembrin, resveratrol, luteolin and caffeic acid phenethyl ester (CAPE) were detected in the pulp as major. Resveratrol varied from 4.50 to 101.89 mg/100 g, while was equally in both the seed and pulp. It was found that all grape samples were rich in phenolic compounds and had antioxidant activity. Conclusion: It was clear that antioxidant capacity and phenolic profile of samples changes according to grape species and cultivars.
AtıfScopus11WoS7OpenAlex10İncele - MakaleAçık Erişim2023Scopus SJRQ1Physicochemical Characterization of Dextran HE29 Produced by the Leuconostoc citreum HE29 Isolated from Traditional Fermented Pickle
İspirli, Hümeyra
In this study, lactic acid bacteria (LAB) strains were isolated from traditional fermented pickles, and among the identified strains, Leuconostoc citreum HE29 with a strong slimy colony profile was further selected to determine the physicochemical and techno-functional properties of its exopolysaccharide (EPS). Glucose was the only sugar monomer in the core unit of EPS HE29 detected by HPLC analysis, and glucan HE29 revealed 7.3 kDa of molecular weight. Structural characterization of glucan HE29 by 1H and 13C NMR spectroscopy analysis demonstrated that EPS HE29 was a dextran-type EPS containing 5.3% levels of (1 → 3)-linked α-D-glucose units. This structural configuration was also supported by FT-IR analysis, which also demonstrated the functional groups within the dextran HE29 structure. In terms of thermal properties detected by TGA and DSC analysis, dextran HE29 demonstrated a degradation temperature of around 280 °C, showing its strong thermal features. A semi-crystalline nature was observed for dextran HE29 detected by XRD analysis. Finally, AFM and SEM analysis revealed tangled network-like properties and web-like branched structures for dextran HE29, respectively. These findings suggest the importance of plant-based fermented products as LAB sources in obtaining novel EPS structures with potential techno-functional roles.
AtıfScopus10WoS9OpenAlex11İncele - MakaleAçık Erişim2023Scopus SJRQ1A new approach for high-quality production of UHMWPE by applying powder vibration densification before sintering
Yilmaz, Galip; Uslu, Emin
Due to its extreme viscosity, UHMWPE powder requires elevated pressure and temperature settings to ensure a fully solid structure. But a gentle process is vital for reliability in certain applications, such as prosthetic liners. A unique type of large gap, not mentioned in the literature, has been observed to resist closing more than regular gaps due to the number of particles forming a shield against pressure. As a solution, a mechanical vibration treatment of the particles before heating was used to eliminate these particular large gaps. Optimum vibration parameters were found, and the samples' final solid density and mechanical properties increased. The particles' dimensions and coefficient of friction were measured, and their vibration-dependent characteristics were discussed. A custom-made microscope apparatus was used to observe the vibration-induced densification of the particles and the gaps resisting closing.
AtıfScopus14WoS14İncele - MakaleAçık Erişim2023Scopus SJRQ3Fatḥ al-Raḥīm al-Raḥmān fī tafsīr Āyat "inna Allāha yaʼmuru bi al-ʻadl wa al-iḥsān" by Abū al-Ḥasan b. ʻAbd al-Raḥmān b. Muḥammad al-Khaṭīb al-Shirbīnī al-Shāfiʻī: Study and Critical Edition; [Ebü’l-Ḥasen b. ʻAbdirraḥmān İbn Muḥammed el-Ḥaṭīb eş-Şirbīnī eş-Şāfiʻī’nin Fetḥu’r-Raḥīmi’r-Raḥmān fī tefsīri Āyeti "innallāhe yeʼmuru bi’l-ʻadli ve’lİḥsān" adlı eseri: İnceleme ve Tahkik]
Aras, Zakir
This study seeks to investigate the treatise of Abū al-Hasan b. Abd al-Rahman b. Muhammad al-Khatīb al-Shirbīnī al- Shāfiʻī (d. after 1028/1619) entitled Fatḥ al-Raḥīm al-Raḥmān fī tafsīr Āyat "inna Allāha yaʼmuru bi al-ʻadl wa al-iḥsān" based on the manuscript of the author. Shedding light on the translation of this unknown scholar, as it is evident from the title of the treatise that it contains the interpretation of this verse, which is well known among scholars and commentators as the most comprehensive verse in the Qur’ān. In this tafsīr, Shirbīnī used many exegetical methods such as exegesis of the Qur'ān with the Qur'ān, exegesis of the Qur'ān with the Sunnah, exegesis of the Qur'ān with the sayings of the Companions, and al-tafsīr bi-al-raʼy, as well as tafsīr approaches such as linguistic tafsīr, the science of munāsabāt, and causality of nuzūl to analyze the meanings of the verse in depth. Another feature that increases the importance of this treatise is that al-Shirbīnī refers to the primary source tafsīr books together with their glosses, sometimes quoting from the commentators verbatim, and sometimes making meaning-based quotations from them, which is the most obvious indication of his exegetical ability and scholarly competence. In this work, he adopted a syncretic approach while emphasizing the meanings of the verse and followed an analytical-critical method while examining the subject. For this reason, he analyzed all the words in the verse one by one, dwelt on the meanings and interpretation of the words, and criticized their views after including the views of the commentators. Therefore, he applied the analytical exegesis method very successfully in this work. Accordingly, he analyzed the narrations related to tafsīr and mentioned the Companions' names during the narration. In particular, he analyzed the narrations from Ibn 'Abbas (d. 68/687-88) about the words al-ʻAdl and al-iḥsān, and stated that there was a dispute between the narrations about the phrase al-iḥsān. He took a scientific stance on the derivation of the word "Allah,” debated between those who accepted it and those who rejected it. He stated that the derivation of the word was not satisfactory and reliable. In the tafsīr of the words al-ʻAdl and al-iḥsān, he discussed the isnāds in Muqātil b. Sulayman’s (d.150/767) tafsīr emphasizing that he received the tafsīr of al-ʻAdl from Ibn 'Abbas and the tafsīr of al-iḥsān from 'Ali b. Abī Tālib. This approach is an important example for the isnād analyses of Muqātil b. Sulayman who was criticized for neglecting isnād chains in his tafsīr. He also criticized al-Baydāwī for being influenced by some of Zamakhsharī's sectarian and theological views. He classified the issue of kinship according to usūl, furū', and hawāshī, expanded the meaning of the verse, and insisted that the message of this verse encompasses all relatives, regardless of the degree of kinship. He was influenced by Latāʾif al-Ishārāt, al-Kashshāf, Mafātīhu al-ghayb, al-Baydawī, Hāshiya al-Jurjānī ala al-Kashshāf, and his grandfather al-Khatīb al-Shirbīnī’s (d.977/1570) al-Sirāj al-munīr.
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