Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(117)
- Kaya, Yunus(51)
- Şahin, Engin(48)
- İspirli, Hümeyra(47)
- Özen, Soner(46)
- Şenay, Volkan(45)
- Pat, Suat(44)
- Can, Zehra(39)
- Bayraktar, Bülent(37)
- Bayram, Sinan(37)
- Korkmaz, Şadan(36)
- Cuce, Erdem(35)
- Ecem Bayram, Nesrin(33)
- Kutlu, Naciye(33)
- Yilmaz, Mustafa Tahsin(32)
- Artar, Musa(31)
- Ertugrul, Mehmet(30)
- Öner, Erdal(30)
- Ayata, Ümit(29)
- Hasar, Ugur Cem(29)
- Esmer, Yusuf(28)
- Mercan, Emin(27)
- Cuce, Pinar Mert(26)
- Özdemir, Akın(25)
- Çolak, Murat(24)
- Bayram, Ozkan(23)
- Kamiloğlu, Aybike(23)
- Sert, Durmuş(22)
- Ayazoglu, Rabil(21)
- Abdioglu, Murat(20)
- Bayram, Nesrin Ecem(20)
- Kadakal, Mahir(20)
- Kara, Yakup(20)
- Kizil, Hamit Emre(20)
- Tozlu, Alperen(20)
- Birinci, Ahmet(19)
- Gerçek, Yusuf Can(19)
- Battal, Fetullah(18)
- Dirican, Ebubekir(18)
- Ergün, Mustafa(18)
Yayınlar
- MakaleAçık Erişim2020Effects of Digital Shot Stories on the Development of Listening Skills: An Action Research
Köroglu, Zeynep Cetin
The present research aimed to find out whether digital short stories can improve language learners' listening skills. The purpose of this study was to figure out student teachers' perceptions of digital short stories' implementation into language classrooms. Specifically, the current research aimed to investigate whether digital short stories are useful to develop language learners' listening skills in English. The research is action research in design. The study used pretest and post-test, a written structured interview to collect data and it included both quantitative and qualitative components. The interview consisted of six open-ended questions. Achievement tests and t-test were used to analyse quantitative data. On the other hand, content analysis was used to analyse qualitative data. The data were collected in 2016-2017 academic years at a state university, Turkey. Participants were preparatory class students of English language teaching department of the university. In the treatment process, digital short stories were used for eight weeks, which were written by various famous American authors and voice recorded by American native speakers of English. Additionally, weekly worksheets and hand-outs were prepared by the researcher. Results showed that digital short stories provide satisfactory content, supports vocabulary learning, improves language learners' listening skills, helps participants to gain familiarity with complex grammar structures and makes students more familiar with different cultures. Furthermore, participants were satisfied with digital short stories and they thought these digital stories are useful to improve their listening skills.
AtıfWoS2OpenAlex13
İncele - MakaleAçık Erişim2020AN APPROXIMATE SOLUTION FOR LORENTZIAN SPHERICAL TIMELIKE CURVES
Aydin, Tuba Agirman
In this article, the differential equation of lorentzian spherical timelike curves is obtained in E-1(4). It is seen that the differential equation characterizing Lorentzian spherical timelike curves is equivalent to a linear, third order, differential equation with variable coefficients. It is impossible to solve these equations analytically. In this article, a new numerical technique based on hermite polynomials is presented using the initial conditions for the approximate solution. This method is called the modified hermite matrix-collocation method. With this technique, the solution of the problem is reduced to the solution of an algebraic equation system and the approximate solution is obtained. In addition, the validity and applicability of the technique is explained by a sample application.
AtıfWoS1İncele - MakaleYalnız künye2020The Influence of Social Media Friendship on Brand Awareness and Purchase Intention: Evidence from young adult consumers
Bilgin, Yusuf
The aim of this study is to analyze the impact of social media friendships on young adult consumers' approach to brands in terms of awareness, image, trust, and purchase intention among. The quantitative research method was used in this study, the population of which consisted of students who were studying at undergraduate level in Turkey and who use either Facebook, Instagram, or Twitter actively. In this study, the convenience sampling method was used. Research data was collected from 1069 undergraduate students through online questionnaires on Facebook, Instagram and Twitter. The data obtained were analyzed using Structural Equation Modeling. The results of the analysis showed that social media friendships among young adult consumers had a positive impact on brand awareness, brand image, brand trust and purchasing intentions. In addition, brand awareness was found to have a strong impact on brand image and brand trust among young adult consumers. However, brand trust was more influential on the purchase intention of young adult consumers than brand image and brand awareness.
AtıfWoS9İncele - MakaleAçık Erişim2020The Relationship Between Weightlifting Trainers' Leadership Characteristics and their Leadership Strength as per the Perceptions of Athletes
Gönen, Mevlut; Kul, Murat; Karatas, Ismail
The research was designed with correlational research model, one of the quantitative approaches. In the selection of the research group, purposeful sampling approaches and convenience sampling method were applied. The research group consists of 351 weightlifters, 136 women and 215 men. The data were obtained using the Personal Information Form, Sports Leadership Scale (SLS) and Sport Leadership Strength Scale-Other (SLSS-O). Relevant Statistical analysis was applied to interpret the data. Consequently, low-level positive correlations between SLS and all sub-dimension mean scores of SLSS-O were determined.
- MakaleYalnız künye2020Investigation of the Effects of 8-Week Zumba and Step-Aerobic Exercises on Serum Leptin and Serum Ghrelin Hormone in Women
Temur, H. Bayram; Öge, Beyza
In this study, it was aimed to investigate the relationship between 8-week-old zumba and step-aerobic exercises with serum leptin and serum ghrelin. Semi-experimental method used in qualitative and quantitative research was used in the study. The experimental group consisted of 26 women who voluntarily participated in the study, with an average age of 41.40 +/- 9.90 years, who did not smoke or drink alcohol, do not exercise regularly, and lead a sedentary life. The experiment group was performed zumba and step-aerobic exercises with various choreographies for 3 weeks, 2 hours each, for 8 weeks. Blood samples were taken to determine the levels of hormone levels of the serum leptin and serum ghrelin three times before the exercise program, the 4th week of the exercise program and the end of the exercise program. Blood samples were taken in the morning hours after 8-10 hours of fasting. The data obtained as a result of the measurements were transferred to the computer environment. SPSS 20 package program was used in the analysis of these data. As a result of the analysis on the normal distribution of data, it was revealed that it showed a normal distribution. In the analysis of these data, Single Factor Variance Analysis (ANOVA) was used. Significance levels were evaluated according to p <0.05. As a result of the statistical analysis of the findings obtained in the research; The participants in the study were found to be statistically insignificant (p> 0.05) although there was a decrease in leptin and ghrelin levels. As a result, regular zumba and stepa-erobic exercises were found to cause a decrease in serum leptin and ghrelin levels in sedentary women, although not statistically significant.
AtıfWoS1İncele - MakaleAçık Erişim2020The Relationship Between Exercise and Body Composition and Liver Enzymes
Temur, H. Bayram; Ceylan, Ramazan
Zumba exercise program applied for twelve weeks to know its effects on Body Mass Index (BMI), Body weight, High Density Lipoprotein (HDL), Low Density Lipoprotein (LDL), Triglyceride (TG) and Aspartate Aminotransferase (AST). A total of 15 women, whose average age was 40.33 +/- 9.15 years, were trained for one and a half hours for 3 days a week for 12 weeks. The blood samples were taken on an empty stomach four times before the training of Zumba and at the end of each week. Blood samples were taken 24 hours after exercise at the end of every four weeks. These blood samples were studied in a healthcare facility laboratory. The lengths and body weights of the participants were also determined. We found that there was a decrease in body weight and BMI measurement values and AST measurement values. However, no significant change in serum HDL, LDL and triglyceride values was evidenced.
AtıfOpenAlex1İncele - MakaleAçık Erişim2020The Perceived Stress Levels During COVID-19 Quarantine Periods and Physical Activity and Exercise
Sahin, Tolga; Gönen, Mevlut
Social life disruption diminished the physical activity and isolation at home caused psychological stress on people during the coronavirus outbreak. This study applied the Perceived Stress Scale (PSS). Five hundred forty-three participants voluntarily completed the online questionnaire. The additional questions were asked to participants such as age, gender, educational status, spent time for physical activity or exercise, and isolation status. The perceived stress level and Insufficient Self-Efficacy perception (ISE) as a sub-factor of PSS were found statistically significant among the activity level groups. When compared to isolation status, the not isolated group showed a higher perception of stress (PSS total score, ISE, and SDP values) than partial and isolated groups except for SDP in partial isolated groups value. The findings of this study revealed that during isolation days which limiting energy expenditure and increasing mentally stress exercise and physical activity could be effective in decreasing perceived stress.
AtıfOpenAlex6İncele - MakaleAçık Erişim2020Optimising High Lime Fly Ash Content By Means of Silica Fume Incorporation to Control Alkali-Silica Reaction And Drying Shrinkage of Mortars
Gökçe, H. Suleyman; Hosseinnezhad, Hojjat; Üzüm, Onur; Hatungimana, Daniel; Ramyar, Kambiz
In this study, the effect of binary and ternary cementitious systems composed of portland cement, high-lime fly ash and silica fume on the compressive strength, alkali-silica reaction (ASTM C 1567) and drying shrinkage of mortar mixtures was researched. For this purpose, binary and ternary binders were prepared with partial replacement of cement with either fly ash (15wt% and 30wt%) or silica fume (5wt%) or both mineral admixtures (15wt+%5wt% and 30wt%+5wt%). An alkali reactive basalt aggregate was used in this study. It was found that partial replacement of cement with high-lime fly ash reduced the strength of mortar mixtures even up to 28-days. Besides, addition of 5% silica fume had not a significant effect on the early strength of fly ash-bearing mixtures. However, silica fume inclusion improved the 28-day strength of mixtures. In terms of alkali-silica reaction (ASR), the fly ash with lower lime content reduced the 14-day expansion more than that of fly ash with higher lime content. The opposite results were the case in 28-day ASR expansions. The ASR expansions of the fly ash-bearing mixtures were significantly reduced by the introduction of the additional 5% silica fume to these mixtures. However, silica fume incorporation remarkably increased the drying shrinkage values of the mixtures. Finally, fly ash with higher lime content was found to be more satisfactory in terms of compressive strength, alkali-silica reaction and drying shrinkage in the ternary binder system.
AtıfOpenAlex1
İncele - MakaleAçık Erişim2020Scopus SJRQ2Removal Kinetics of Olive-Mill Wastewater in a Batch-Operated Aerobic Bioreactor
Kul, Sinan; Nuhoglu, Alper
This study involves the removal of the olive-mill wastewater (OMW), which is a significant pollutant, in a batch reactor under aerobic conditions by mixed cultures. It also includes comparison of different substrate inhibition models, calculation of kinetic parameters, and testing the merit of the chosen mathematical model with respect to OMW concentration and changes with time. Average initial microorganism concentration (X0) in the batch reactor was 100 +/- 15 mg L-1. During the study the treatment of OMW with initial chemical oxygen demand (S0) concentration between 10 and 1,000 mg COD L-1 was investigated. Maximum specific growth rate (mu max) was reached with 130 mg COD L-1 initial concentration and 3 h experimental duration produced 57.17% chemical oxygen demand (COD) removal efficiency. Other experiments with increasing initial concentration increased COD removal duration, with 927 mg COD L-1 initial concentration regressing to 8.88% removal efficiency after 3 h. The biokinetic equations of Aiba, Haldane, Tseng, and Yano and Koga were chosen to relate S0 concentration to specific growth rate (mu) and the biokinetic parameters in these equations were calculated. The most appropriate biokinetic equation was the Haldane model in terms of R2 value and the Haldane equation parameters 0.43 h-1, 45.34 mg L-1, and 207.97 mg L-1 were calculated for mu max, half-saturation constant (Ks) and inhibition constant (Ki), respectively. Also, a mathematical biokinetic model including the Haldane equation was used to test the OMW removal performance and it was seen that the chosen model was well able to reflect system behavior. After the calibration of mu max, the most-sensitive parameter of the Haldane model, to 0.22 h-1, the model gave a better fit for all tested conditions.
AtıfWoS2OpenAlex7İncele - MakaleAçık Erişim2020Forecasting the movements of Bitcoin prices: an application of machine learning algorithms
Pabuçcu, Hakan; Ongan, Serdar; Ongan, Ayse
Cryptocurrencies, such as Bitcoin, are one of the most controversial and complex technological innovations in today's financial system. This study aims to forecast the movements of Bitcoin prices at a high degree of accuracy. To this aim, four different Machine Learning (ML) algorithms are applied, namely, the Support Vector Machines (SVM), the Artificial Neural Network (ANN), the Naive Bayes (NB) and the Random Forest (RF) besides the logistic regression (LR) as a benchmark model. In order to test these algorithms, besides existing continuous dataset, discrete dataset was also created and used. For the evaluations of algorithm performances, the F statistic, accuracy statistic, the Mean Absolute Error (MAE), the Root Mean Square Error (RMSE) and the Root Absolute Error (RAE) metrics were used. The t test was used to compare the performances of the SVM, ANN, NB and RF with the performance of the LR. Empirical findings reveal that, while the RF has the highest forecasting performance in the continuous dataset, the NB has the lowest. On the other hand, while the ANN has the highest and the NB the lowest performance in the discrete dataset. Furthermore, the discrete dataset improves the overall forecasting performance in all algorithms (models) estimated.
AtıfWoS25OpenAlex65İncele - MakaleAçık Erişim2020Scopus SJRQ1Physical and mechanical properties of cement containing regional hazelnut shell ash wastes
Baran, Y.; Gökçe, H. S.; Durmaz, M.
Turkey is ranked in the first place with two-thirds of the world hazelnut production. As the amount of shell obtained from shelled-hazelnut is almost equal to that of hazelnut by weight, the shell is a regionally important waste. The biomass is consumed as a fuel in some homes, workplaces, and public buildings with the help of specific caldrons. In the study, the use of ash was researched in the production of blended cement. For this purpose, blended cement mixtures containing hazelnut shell ash at the ratios of 0, 5, 10, 15, 20, 25 and 30% by weight of CEM I 42.5R ordinary Portland cement were prepared. The binary cementitious systems were assessed in terms of chemical, physical and mechanical properties. Hazelnut shell ash introduction increased the water demand up to 59% for standard consistency and reduced setting time up to 96% according to the ordinary Portland cement. Compressive strength results were remarkably reduced by an increase in the amount of ash. With over 5% of hazelnut shell ash introduction, the 28-d compressive strength value was found unsatisfactory (<42.5 MPa). The insufficient total amount of SiO2+Fe2O3+Al2O3 reduced the usage amount of the biomass ash in cementitious products due to having no pozzolanic characteristic. Hazelnut shell ash can be used as an alkaline set accelerator in concrete products as it is not steel-reinforced due to its high chlorine ion content. (C) 2020 Elsevier Ltd. All rights reserved.
AtıfWoS35OpenAlex41İncele - MakaleYalnız künye2020Scopus SJRQ14-aminothiophenol-intercalated montmorillonite: Organic-inorganic hybrid material as an immobilization support for biosensors
Yilmaz, Yahya Yasin; Yalcinkaya, Esra Evrim; Demirkol, Dilek Odaci; Timur, Suna
Hybrid materials containing organic and inorganic structures are very important because they have the advantages of each of their components. Intercalation of the organic molecule to inorganic structures such as clay allows the preparation of multifunctional new immobilization matrices that contain both the strength properties of the clays and the properties of the organic molecule such as its functional groups (amine, carboxyl or hydroxyl etc.). In this study, 4-aminothiophenol intercalated montmorillonite (4ATP-Mt) was prepared and used as an immobilization layer for the pyranose oxidase (PyOx) enzyme on a glassy carbon (GC) electrode. Firstly, 4ATP intercalation of Mt was carried out, and the success of intercalation was proven using Fourier-Transform Infrared Spectroscopy (FTIR), X-ray Diffractometer (XRD), and Thermogravimetric Analysis (TGA) techniques. Then PyOx was immobilized using 4ATP-Mt, BSA and glutaraldehyde as a cross-linker on the surface of GC electrodes. To show the coating steps for the preparation of 4ATP-Mt/PyOx biosensors, cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques were applied, and surface morphology was visualized by scanning electron microscopy (SEM). After optimization of working conditions, analytical performance parameters were determined for glucose detection. The 4ATP-Mt/PyOx biosensor exhibited a wide linear concentration range between 0.01 and 0.5 mM (LOD: 1.0 mu M) for glucose. Additionally, the fabricated 4ATP-Mt/PyOx was assayed for the analysis of glucose in artificial body fluids and drinks.
AtıfWoS40OpenAlex48İncele - MakaleAçık Erişim2020Scopus SJRQ3Effect of loading rate on cohesive parameters of the adhesive Araldite 2015
Erbayrak, Engin; Ozer, Halil
This study addresses the effect of loading rates on cohesive parameters and microstructural composition of the Araldite 2015 adhesive. Double Cantilever Beam (DCB) samples were tested under the loading rates of 1, 5, 10, 20, 100 and 200 mm x min(-1). The Park-Paulinho-Roeser model (PPR model) was used to get cohesive parameters. In modelling of the softening behavior, inverse analyses were performed using the date obtained from the PPR softening curves. It was seen that the fracture energy and cohesive parameters are decreasing with increasing the loading rate. However, there seems to be a transition region where the fracture energy nearly remains constant. Microstructural analyses were implemented in order to study the effects of the loading rates on the characteristics of the fracture surfaces. It was concluded that the loading rates greatly influence the distribution of micro-voids in the epoxy matrix. Moreover, the presence of voids in epoxy matrix improved the plastic deformation around the crack tip and increased the fracture toughness.
AtıfWoS3İncele - MakaleYalnız künye2020The Effect of Protein and Carbohydrate Consumption during 10-Week Strength Training on Maximal Strength and Body Composition
Ozan, Murat; Buzdagli, Yusuf; Siktar, Erdinc; Ucan, Izzet
In this study, it was aimed to examine the effect of protein and carbohydrate consumption on repetitive maximal strength and body composition during the 10-week strength training. The mean age and height of the groups are as follows; experimental group CAR: (n=10) 20.04 +/- 1.38 years, 173.44 +/- 4.62 cm, PR (n=10) 21.29 +/- 2.44 years, 177.24 +/- 4.22 cm and placebo group; PLA (n=10) 20.14 +/- 2.19 years, 174.15 +/- 5.12 cm in total and 30 inactive male individuals participated in the evaluation. The research was conducted as a single blind study. Scitec Isolate Whey Protein and Hardline Carbopure supplementation was given to the experimental groups under the researcher supervision for 10 weeks in appropriate for daily use type and dose. 0.75 g/kg protein was given to the PR group two hours before the training, 0.75 g/kg protein was given immediately after the training and totally 1.5 g/kg 500ml water and protein supplement was given on the days of training. In carbohydrate supplementation, carbohydrate supplements were applied as 3.0 g/kg two hours before the training and 3.0 g/kg immediately after the training, and a total of 6 g/kg 500m1 water on the days of training. In the research, synthetic colorant, which does not increase blood sugar, was given to the PLA group with 500m1 water in equal amounts to the given supplement. As a result; while the use of carbohydrate and protein supplements in the 10-week strength training performed 4 days a week provided positive improvements on body composition and 1MT, especially the use of protein provided more positive developments on fat percentage and lean body mass.
AtıfWoS3İncele - MakaleYalnız künye2020Scopus SJRQ4Some physicochemical and microbiological properties of butter produced in Erzurum
Akgül, Halil Ibrahim; Sengül, Mustafa; Ürkek, Bayram; Kotan, Tuba Erkaya; Gürbüz, Zeynep
The goal of this study was to determine some physicochemical and microbiological properties of Erzurum butter. Random samples (n = 30) were collected from different retail markets throughout Erzurum province. The pH, acidity, and melting point values of samples were 3.88, 0.47%, and 30.03 degrees C, respectively. The salt, fat, and moisture values of some samples (sample no 1, 14, and 18) were not harmony with Turkish Food Codex. The highest and lowest peroxide, iodine, saponification, Reichert-Meissl (RM), and Polenske values were found to be in the range of 0-0.51 mEqO2/kg, 22.97-38.64, 195.45-228.54, 17.08-30.-56, and 0.72-1.80, respectively. The refractive index value (RI) was changed from 1.4591 to 1.4620. Total coliforms, aerobic mesophilic bacteria (TAMB), lactic acid bacteria (cultured in MRS and M17), and mould and yeasts mean counts were 1.07 log CFU g-1, 6.79 log CFU g-1, 6.45 log CFU g-1, 6.76 log CFU g-1, and 5.33 log CFU g-1, respectively. There were high differences in physicochemical and microbiological properties of butter might be attributed to a non-standard production process as well as non-standard raw material. In sum, the sanitation and storage conditions should be improved from production to consumption to improve the butter quality.
AtıfWoS1İncele - MakaleYalnız künye2020Scopus SJRQ3Effect of resin content on tribological behavior of brake pad composite material
Yanar, Harun; Ayar, Hasan Huseyin; Demirtas, Muhammet; Purcek, Gencaga
Purpose This paper aims to investigate the effect of straight phenolic resin content on the fade behavior, frictions and wear characteristics of pre-determined brake pad composite matrix having specific amount of barite (BaSO4), rock wool, Kevlar, graphite and magnetite. Design/methodology/approach Different amount of resin ranging between 16 and 20 wt. per cent were added by changing only the filler (barite) content of composite matrix. Subsequently, friction and wear behavior of the composite samples were analyzed using a special pin-on-disc type test system developed for brake pad sample. The worn surfaces were investigated by SEM and three-dimensional (3D) surface profilometer. Findings The average coefficient of friction (CoF) of composite samples and temperature of the disc surface showed a linear increase with decreasing the resin content. The sample having 20 wt. per cent resin showed the minimum wear rate with smooth worn surface. But the amount of fade is quite high in that sample. Decreasing resin content decreased the fade formation, and the composite with 16 per cent resin brought about the minimum fade formation. As the fade formation is unwanted in brake pad applications, the composite with 16 wt. per cent resin was proposed as the most appropriate one considering the performance parameters related to friction and wear. Originality/value This paper optimizes the resin content of composite brake pad materials to achieve the best combination of its tribo-performance and mechanical properties and provides valuable information for scientists and engineers working in that area.
AtıfWoS8OpenAlex15İncele - MakaleYalnız künye2020The Effects of Strenght Exercises on Body Composition and Irisin
Ozan, Murat; Karakurt, Sercan; Aggon, Eser; Agirbas, Ozturk; Ucan, Ezzet; Alp, Hamit Hakan
This is the first study to determine the effects of strenght exercises on irisin and correlation of bady composition and irisin. The purpose of this study was to determine the effects on body composition and irisin of static strength exercises with Tera-Bant (R) in elite boxers. 9 volunteered elite male boxers participate in the study who are nonsmokers and did not use any nutritional supplements. Boxers were instructed to perform strength exercises with Thera-Band for 3 days a week for 8 weeks. Blood samples were taken before exercises (resting), after the first exercise (acute) and after 8 weeks following the last exercise (chronic), and measurement of body fats were made at the same time. Irisin levels of blood were examined. Statistical analyses were carried out using the SPSS 22 for Windows. The data were found to not be distributed normally. Thus, Friedman, Wilcoxon, Mann-Whitney U and Speraman's correlations tests were used. The results were evaluated using an alpha level of .05. Body Fat Percentage (BFP) and Fat Mass (FM) levels of athletes increased, Lean Mass (LM) decreased relatively both after a single session and after 8 weeks. While irisin concentration increased after a single session, (correlation in pre exercise and after a single exercise. Static strength exercise is effective on body fat both acutely and chronically, and effective on irisin only acute. Farther, the body fat and irisin are related to the negative.
AtıfWoS2İncele - MakaleAçık Erişim2020Scopus SJRQ1Development of Eco-Efficient Fly Ash-Based Alkali-Activated and Geopolymer Composites with Reduced Alkaline Activator Dosage
Gökçe, H. S.; Tuyan, M.; Ramyar, K.; Nehdi, M. L.
The eco-efficiency and economy of geopolymer composites largely depend on their alkaline activator dosage. In this study, the effect of applying a pre-setting pressure and variation of the aggregate-to-fly ash ratio on the alkaline solution dosage and mechanical strength of fly ash-based geopolymer composites was explored. It is shown that through control of the aggregate-to-ash ratio and application of pre-setting pressure, compressive strength could be increased by 102% and 86% for Class F fly ash-based geopolymer and alkali-activated Class C fly ash-based mixture, respectively. The total alkaline solution consumption could be reduced from 718 to 188 kg/m(3) and from 769 to 262 kg/m3 for Class F fly ash-based geopolymer and alkali-activated Class C fly ash-based mixture, respectively. The proposed method reduced the alkaline solution consumption per compressive strength (6.2 kg.m(-3).MPa-1) by up to 85% compared to that of the reference manually consolidated control geopolymer. The findings demonstrate that fly ash-based geopolymers could be made more sustainable and eco-efficient through tailored production techniques. (C) 2019 American Society of Civil Engineers.
AtıfWoS23OpenAlex30İncele - MakaleAçık Erişim2020Scopus SJRQ2Comparison of two wild-grown Berberis varieties based on biochemical characterization
Çakır, Özlem; Karabulut, Abdulkadir
In this study, some physicochemical properties, antioxidant activity, total phenolic content, mineral content, and phenolic profiles of Berberis vulgaris and Berberis crataegina wild-grown in Bayburt are analyzed and compared. The level of total phenolic content in B. crataegina DC. (73.48 µg GAE/mg KM) was found higher than B. vulgaris (71.54 µg GAE/mg KM). According to three methods (β-carotene, 2,2-diphenyl-1-picrylhydrazyl, and cupric reducing antioxidant capacity) the antioxidant activity of the B. crataegina is also higher. The change in color (L*, b*) is found statistically important (p <.05). There are no meaningful differences between the dry matter, C vitamin, pH value, and water activity (p >.05). It was observed that the fruit type has a great effect on brix and ash content (p <.05) and glucose, total sugar, and malic acid content. Chlorogenic acid is the dominant phenolic component for both types. It is followed by syringic, sinapic, and gallic acid in B. vulgaris and sinapic, syringic, and gallic acid in B. crataegina. Practical applications: Wild fruits have been consumed for centuries in nutrition or pharmacology applications. They are known as rich resources of antioxidant and phenolic compounds. For that reason, wild fruits play an important role in the prevention and treatment of some diseases especially cardiovascular diseases and cancer. In this study, wild-grown B. vulgaris and B. crataegina were analyzed in detail according to their bioactive properties and an assessment was made in terms of industrial and medical usability. This study reports mineral content, antioxidant activity, total phenolic content, and the phenolic acid profile (sinapic, syringic, gallic, chlorogenic, caffeic, vanillic, trans-ferulic, p-coumaric, and 4-hydroxybenzoic acids) of two Berberis varieties. According to results, these fruits may be used as natural flavoring and coloring material in food sector. Thanks to the active ingredients and minerals; these fruits may be used in pharmaceutical industry. They have a good potential for commercial exploitation and positive effects on health.
AtıfScopus16WoS8OpenAlex16
İncele - MakaleYalnız künye2020Scopus SJRQ1Structural and physicochemical characterisation and antioxidant activity of an α-D-glucan produced by sourdough isolate Weissella cibaria MED17
Aburas, Hani; İspirli, Hümeyra; Taylan, Osman; Yilmaz, Mustafa Tahsin; Dertli, Enes
An exopolysaccharide (EPS) producer slimy-mucoid type colony was isolated from sourdough and identified as Weissella cibaria MED17. The 1H and 13C NMR spectra of EPS MED17 demonstrated that this EPS was a dextran type glucan ((1 → 6)-linked α-D-glucose core structure) containing (1 → 3)-linked α-D-glucose branches and proportion of (1 → 6)-linked α-D-glucose units to (1 → 3)-linked α-D-glucose units was 94.3:5.7%. The FTIR analysis also confirmed the (1 → 6)-linked α-D-glucose linkage. A high level of thermal stability was observed for glucan MED17 as no degradation up to 300 °C was observed by TGA and DSC analysis. The XRD analysis of glucan MED17 showed its semi- crystalline nature and its compact sheet-like morphology was observed by SEM analysis. Finally, antioxidant characteristics of glucan MED17 were determined by ABTS and DPPH radical scavenging activity tests that revealed a moderate antioxidant activity of glucan MED17. These findings show potential techno-functional characteristics of glucan MED17.
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