Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Kutlu, Naciye(11)
- Şahin, Engin(6)
- Ecem Bayram, Nesrin(5)
- Sönmez Sari, Ebru(5)
- Can, Zehra(4)
- Gerçek, Yusuf Can(3)
- Gıdık, Betül(3)
- Kalay, Erbay(3)
- Kamiloğlu, Aybike(3)
- Kızıl, Hamit Emre(3)
- Saritas, Serdar(3)
- Semerci Çakmak, Vahide(3)
- Teber, Ahmet(3)
- Abca, Tuğba Elbir(2)
- Abdioglu, Murat(2)
- Aksoy, Dilara Arzugül(2)
- Apaydin, Emine(2)
- Arslaner, Ayla(2)
- Bayram, Nesrin Ecem(2)
- Bayram, Sinan(2)
- Baştürk, Fatma Nur(2)
- Birinci, Ahmet(2)
- Dertli, Enes(2)
- Gercek, Yusuf Can(2)
- Guner, Sait Baris(2)
- Gunes, Huseyin(2)
- Isci, Asli(2)
- Kahveci, Hakan(2)
- Kamiloglu, Aybike(2)
- Kara, Yakup(2)
- Koroglu Kaba, Nagihan(2)
- Ozdemir, Ahmet(2)
- Sakiyan, Ozge(2)
- Terzi, Handan(2)
- Tozlu, Alperen(2)
- Çelik, Saffet(2)
- Öztekin, Sebahat(2)
- Acar, Emre Ali(1)
- Adal, Samiye(1)
- Adiyaman, Gokhan(1)
Yayınlar
- MakaleYalnız künye2023Scopus SJRQ2The effect of guided imagery applied on geriatric orthopaedic patients on preoperative anxiety and comfort
Gunes, Huseyin; Saritas, Serdar; Ozdemir, Ahmet; Bulbul, Ali Savas
Background: This study was designed to examine the effect of guided imagery applied to geriatric orthopaedic patients on preoperative anxiety and comfort. Methods: This study was conducted as a randomized controlled trial. The population of the study consisted of geriatric patients treated in the orthopaedics and traumatology clinic of a university hospital. The sample consisted of 80 patients, including the experimental group (n = 40) and the control group (n = 40). Personal Descriptive Form, The State–Trait Anxiety Inventory (STAI) and General Comfort Scale were used as data collection tools. Results: After the guided imagery application, it was determined that the anxiety of the experimental group decreased statistically significantly, and their comfort improved (P < 0.05). Conclusion: After the imagery, it was determined that the patients in the experimental group had a decrease in their anxiety level and an improvement in their comfort. Since it is a low-cost and easily accessible method, applying imagery in the preoperative period is recommended.
AtıfScopus5WoS5OpenAlex5
İncele - MakaleAçık Erişim2023Scopus SJRQ2Utilization of Response Surface Methodology in Optimization of Proline Extraction from Castanea sativa Honey
Ecem Bayram, Nesrin; Kutlu, Naciye; Can Gercek, Yusuf
Proline constitutes approximately 85 % of the amino acid composition of honey. Therefore, the quantitative determination of this amino acid in honey samples is used by many national/international authorities to evaluate the quality of honey types. In this study, it was aimed to achieve maximum proline amino acid extraction from honey samples whose botanical origins were confirmed by melissopalynological analysis. For this reason, based on three different spectrophotometric methods used in the literature for proline analysis, proline extraction was optimized with the Response Surface Method (RSM) and Box-Behnken experimental design. Three independent variables were determined as treatment time (2, 6, and 10 min), treatment temperature (22, 46, and 70 °C), and cooling time (5, 25, and 45 min). As a result of the optimization, it was seen that only significantly effective independent variable on the proline content of honey was the processing temperature. The optimum conditions obtained as a result of the RSM were found to be 2 min for the treatment time, 70 °C for the treatment temperature and 45 min for the cooling time. The composite desirability of the optimum conditions (R2) was found to be 1.00. It was determined that the method proposed by International Honey Commission (IHC) is efficient for proline analysis, but it provides more proline extraction by reducing of time from 10 min to 2 min in hold time in boiling water bath only during the extraction step. As a result, the conditions to be used in order to achieve maximum proline extraction with different spectrophotometric methods were determined and optimum values were determined. In addition, since the botanical origin of honey samples significantly affects the proline content of honey, it can be suggested that this study be optimized for different monofloral honey samples as well.
AtıfScopus7WoS4OpenAlex8İncele - MakaleYalnız künye2023Scopus SJRQ1Investigation of the effect of group counselling based on schema therapy on academic expectation stress in high school students
Koçak, Lokman; Çelik, Eyüp
This research is a preliminary evaluation study to determine whether group counselling based on schema therapy has an effect on academic expectation stress in high school students. In this study, a 2 × 3 split-plot design was used. The Academic Expectation Stress Inventory was applied for data collection purposes. The effect of group counselling based on schema therapy on academic expectation stress was tested using a two-factor ANOVA for mixed measurements. As a result of the analysis, the intervention*time effect was found to be significant with regard to academic expectation stress. The findings obtained in the study reveal that group counselling based on schema therapy creates a significant decrease in adolescents' academic expectation stress level, and this decline continues, as shown in the follow-up test. As a result, it can be said that the group counselling programme based on schema therapy, which was developed as a preliminary evaluation study, has the potential to reduce the academic expectation stress level of high school students.
AtıfScopus3WoS2OpenAlex3İncele - MakaleYalnız künye2023Scopus SJRQ3The effects of heat treatment temperatures on photocatalytic activity of cobalt ferrite nanoparticles synthesised by microwave-assisted combustion method
Karakaş, Ibrahim Hakki; Karcioğlu Karakaş, Zeynep
In this study, the effects on the photocatalytic activities of particles after heat treatment has been applied to cobalt ferrite nanoparticles produced by microwave-assisted combustion method were observed. The heat treatment applied to the samples was produced with only the microwave effect, at temperatures ranging from 300 to 1000°C. Thermogravimetric analysis was performed on the precursor sample in air atmosphere. During this analysis, the gases released up to 1200°C were identified with a Fourier-transform infrared (FTIR) spectrometer integrated into a thermogravimetric analysis system. Then, the cobalt ferrite nanoparticles produced with heat treatments applied at various temperatures were used as a photocatalyst to remove the dyestuff content in synthetic wastewaters prepared by using Astrazon Red GTL textile dye by photocatalytic oxidation, and their photocatalytic activities were compared. In these experiments, the operational parameters for photocatalysis processes were applied as 400 rpm for stirring speed, 50 mg/L for initial contaminant concentration, 0.5 g/L for catalyst dosage, 25°C for temperature, and 4400 μW/cm2 for light intensity. As a result of the experiments, it was observed that the crystal structure of the cobalt ferrite nanoparticles produced with the increase of the applied heat treatment temperature improved significantly. The obtained data show a strong relationship between the structural properties of materials and their photocatalytic activities. In addition, it was determined that the dyestuff in the solution was completely degraded in the experiments, and it was determined that all processes were compatible with the pseudo-first-order kinetic model.
AtıfScopus4WoS5OpenAlex6İncele - MakaleAçık Erişim2022Scopus SJRQ2On the plane receding contact between two functionally graded layers using computational, finite element and artificial neural network methods
Öner, Erdal; Şengül Şabano, Bahar; Uzun Yaylacı, Ecren; Adıyaman, Gökhan; Yaylacı, Murat; Birinci, Ahmet
The frictionless double receding contact problem for two functionally graded (FG) layers pressed by a uniformly distributed load is addressed in this paper. The gradation in the layers is assumed to follow an exponential variation through the height with constant Poisson's ratios. The lower layer rests on a homogeneous half-plane (HP). There is no adhesion between the FG layers or between the lower layer and the HP. The body forces of the FG layers and HP are ignored. First, the governing equations are reduced to a system of two singular integral equations with contact pressures and contact lengths as unknowns using Fourier transform techniques and boundary conditions. The integral equations are solved numerically using the Gauss-Chebyshev integration formula. Then, a parametric finite element analysis is performed using the augmented contact method. Finally, the problem was extended based on the multilayer perceptron (MLP), an artificial neural network used for different problem parameters. The effects of stiffness parameters, the normalized load length, the ratio of shear moduli, the ratio of FG layer heights to the normalized contact lengths, and normalized maximum contact pressures are explored. The results of finite element analysis and the MLP approach are used to validate the normalized maximum contact pressures and contact lengths obtained from an analytical method based on elasticity theory, and finally, good agreement between these three methods results is obtained. The obtained results could help in designing multibody indentation systems with FGMs.
AtıfScopus85WoS84OpenAlex48İncele - MakaleYalnız künye2022Scopus SJRQ3Optimization of asymmetric reduction conditions of 2-bromo-1-(naphthalen-2-yl)ethanone by Enterococcus faecium BY48 biocatalyst with A-optimal design-embedded model
Özdemir, Akın; Şahin, Engin
Aromatic α-halohydrins, especially 2-haloethanols, which are a common pharmacological precursor, may be readily transformed to chiral β-adrenergic receptor blockers. Studies including the synthesis of (S)-2-bromo-1-(naphthalen-2-yl)ethanol ((S)-2), an α-halohydrin, in high conversion, enantiomeric excess (ee), and yield by biocatalytic asymmetric reduction of 2-bromo-1-(naphthalen-2-yl)ethanone (1) are still insufficient. Moreover, asymmetric reduction of substrate 1 using a mathematical optimization method is not explored in the current literature. In this article, the four asymmetric bioreduction conditions, which are (1) pH, (2) temperature, (3) incubation period, and (4) agitation speed, of substrate 1 were optimized to obtain (S)-2 with A-optimal design-embedded model in the presence of Enterococcus faecium BY48. Optimum bioreduction conditions were determined by the A-optimal design-embedded model as follows: pH = 7, temperature = 25°C, incubation period = 24 h, and agitation speed = 200 rpm. And then, it was suggested that (S)-2 could be obtained with 98.88% ee and 100% conversion rate (cr) under these optimum conditions. As a result of the experimental reaction performed under the optimization conditions suggested by the model, (S)-2 was obtained with 99% ee and 100% cr. The study revealed that E. faecium BY48 could be used as a biocatalyst in asymmetric reduction reactions. Also, the A-optimal design-embedded model could have the great potential to obtain the optimum asymmetric bioreduction conditions.
AtıfScopus3WoS3OpenAlex4İncele - MakaleAçık Erişim2022Scopus SJRQ2Magnetic levitation force and trapped field properties of multiseeded YBCO with triangular arrangement of seeds
Abdioglu, Murat; Guner, Sait Baris; Ozturk, Kemal; Yang, Chiaming; Chen, Ingann; Celik, Sukru
Although there are studies in literature using different number of seeds with different arrangements, especially line and rectangular, it is seen that there is no detailed study handling the levitation force together with trapped field properties of triangular arrangement of seed in YBCO. Therefore, to further investigate the magnetic properties of seeded YBCO superconductors, we have fabricated cylindrical YBCO (YBa2Cu3O7) superconductors with triangular arrangement of the seeds with different seed distances. Maximum levitation force values were obtained as 39.4 N and 57.1 N, while the maximum guidance force values were obtained as −4.6 N, and −8.7 N, respectively, with single-seeded and triangular-seeded samples with seed distance of 14 mm. It was determined that the trapped field, levitation force, and guidance force firstly decreased from the single-seeded sample to the triangular-seeded sample with small seed distance and then increased with increasing seed distance. Increased field trapping and levitation force performances in the triangular-seeded samples with suitable seed distance indicate that the triangular arrangement of seeds is an eligible method to produce larger dimension YBCO samples with bigger shielding current radius and bigger averaged trapped field values.
AtıfScopus4WoS4OpenAlex4İncele - MakaleAçık Erişim2022Scopus SJRQ1Assessment of technological attributes of autochthonous starter cultures in Turkish dry fermented sausage (sucuk)
Kaban, Güzin; Sallan, Selen; Çinar Topçu, Kübra; Sayın Börekçi, Bilge; Kaya, Mükerrem
The study aims to evaluate the technological properties of autochthonous strains (Lactobacillus sakei S15, Lactobacillus plantarum S24, L. plantarum S91, Pediococcus pentosaceus S128b and Staphylococcus carnosus G109) in Turkish dry fermented sausage (sucuk). After 24 h of fermentaPtion, all lactic acid bacteria strains reduced the pH to below 5.0, while the pH in the control group was above 5.3. The number of lactic acid bacteria strains reached 108–109 cfu g−1 during fermentation. Staphylococcus carnosus G109 remained at the inoculation level of 106 cfu g−1 during ripening. Lactobacillus sakei S15 as mono-culture showed higher TBARS values compared to other strains. The control group had the lowest L* value and autochthonous strains caused no significant difference for a* value. According to principal component analysis results, most volatile compounds were positively correlated with the group containing only L. sakei S15.
AtıfScopus25WoS23OpenAlex25İncele - MakaleYalnız künye2022Scopus SJRQ1Changes of some bioactive and physicochemical properties during the black tea processing
Balaban, Osman Tolga; Kamiloğlu, Aybike; Kara, Hasan Hüseyin
Abstract: In this research, some physical and bioactive properties of tea samples collected from every processing stage of black tea production were investigated. The processing stages were significantly effective on the investigated properties (moisture content, color parameters [L*, a*, and b*], and pH values the total phenolic substance, antioxidant activity) (p < 0.01). The antioxidant activities were found to be at a high level in fresh tea but decreased during the processing stages. Furthermore, the lowest activity was observed in the drying stage for extracts prepared with water and in the drying and sorting stages for extracts prepared with ethanol. In addition, it was determined that palmitic acid, myristic acid, and capric acid as saturated fatty acids, oleic acid, heptadecenoic acid, and eicosenoic acid as unsaturated fatty acids formed the fatty acid profile. Palmitic acid was determined to be the dominant fatty acid in tea samples. Practical Application: Tea is a beverage known to have positive health effects. The chemical structure of tea is very effective in providing these positive effects on health. Black tea production takes place in five stages in general terms (withering, rolling, oxidation, drying, and sorting stages) after the harvesting. These processes are very effective in the quality properties of tea. This research provides information about effects of processing stages on black tea. Our results demonstrate that processing was significantly effective on the physicochemical and bioactive properties of tea. Functionality of bioactive compounds could be maintained by optimization of the applied processes.
AtıfScopus16WoS14OpenAlex15İncele - MakaleYayıncıda açık erişim2022Scopus SJRQ1Analysis of mitochondrial DNA cytochrome-b (CYB) and ATPase-6 gene mutations in COVID-19 patients
Dirican, Ebubekir; Savrun, Şeyda Tuba; Aydın, İsmail Erkan; Gülbay, Gonca; Karaman, Ülkü
Coronavirus disease of 2019 (COVID-19) is a pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Mutations of mitochondrial DNA (mtDNA) are becoming increasingly common in various diseases. This study aims to investigate mutations in the cytochrome-b (CYB) and adenosine triphosphatase-6 (ATPase-6) genes of mtDNA in COVID-19 patients. The association between mtDNA mutations and clinical outcomes is investigated here. In the present study, mutations of the mtDNA genes CYB and ATPase-6 were investigated in COVID-19 (+) (n = 65) and COVID-19 (−) patients (n = 65). First, we isolated DNA from the blood samples. After the PCR analyses, the mutations were defined using Sanger DNA sequencing. The age, creatinine, ferritin, and CRP levels of the COVID 19 (+) patients were higher than those of the COVID-19 (−) patients (p = 0.0036, p = 0.0383, p = 0.0305, p < 0.0001, respectively). We also found 16 different mutations in the CYB gene and 14 different mutations in the ATPase-6 gene. The incidences of CYB gene mutations A15326G, T15454C, and C15452A were higher in COVID-19 (+) patients than COVID-19 (−) patients; p < 0.0001: OR (95% CI): 4.966 (2.215−10.89), p = 0.0226, and p = 0.0226, respectively. In contrast, the incidences of A8860G and G9055A ATPase-6 gene mutations were higher in COVID-19 (+) patients than COVID-19 (−) patients; p < 0.0001: OR (95%CI): 5.333 (2.359−12.16) and p = 0.0121 respectively. Yet, no significant relationship was found between mtDNA mutations and patients' age and biochemical parameters (p > 0.05). The results showed that the frequency of mtDNA mutations in COVID-19 patients is quite high and it is important to investigate the association of these mutations with other genetic mechanisms in larger patient populations.
AtıfScopus14WoS16OpenAlex21İncele - MakaleAçık Erişim2022Scopus SJRQ1Easy-to-Implement Ultra-Thin, Wide-Band, and Multi-Functional Polarization Converter for K and Ka Band Applications
Coskun, Aykut; Hasar, Ugur Cem; Ozmen, Ahmet; Ertugrul, Mehmet
This article presents an ultrathin, broadband, and multipurpose polarization converter design utilizing an anisotropic metasurface for K and Ka band. The proposed polarization converter, which has a single layer F4B as a substrate material with hexagonal-shaped metallic solid structure along with hexagonal ring with diagonal splits on its front surface and a background (a completely metallic surface) on its back, works as not only a circular polarization converter but also a linear polarization to circular polarization (LP to CP) converter. Its polarization conversion rate (PCR) is more than 90% in the frequency range from 17.87 to 43.15 GHz, covering all of the K and Ka bands with a relative bandwidth of 83% under normal incidence case. For incidence angles up to 40°, PCR is observed to be greater than 75% in almost all of the K and Ka bands (except for the frequency range between 24.72 and 27.11 GHz). Furthermore, the proposed design has LP to CP in two different frequency bands, 16.23–16.74 GHz and 48.6–48.8 GHz. The proposed polarization converter, as advantages, is low cost, ultra thin, broadband, and facile, which can be useful in linear cross polarization conversion in K and Ka band applications.
AtıfScopus10WoS9OpenAlex10İncele - Derleme MakaleAçık Erişim2022Scopus SJRQ1Impact of different microwave treatments on food texture
Kutlu, Naciye; Pandiselvam, Ravi; Saka, Irem; Kamiloglu, Aybike; Sahni, Prashant; Kothakota, Anjineyulu
Electromagnetic waves are frequently used for food processing with commercial or domestic type microwave ovens at present. Microwaves cause molecular movement by the migration of ionic particles or rotation of dipolar particles. Considering the potential applications of microwave technique in food industry, it is seen that microwaves have many advantages such as saving time, better final product quality (more taste, color, and nutritional value), and rapid heat generation. Although microwave treatment used for food processing with developing technologies have a positive effect in terms of time, energy, or nutrient value, it is also very important to what extent they affect the textural properties of the food that they apply to. For this purpose, in this study, it has been investigated that the effects of commonly used microwave treatments such as drying, heating, baking, cooking, thawing, toasting, blanching, frying, and sterilization on the textural properties of food. In addition, this study has also covered the challenges of microwave treatments and future work. In conclusion, microwave treatments cause energy saving due to a short processing time. Therefore, it can be said that it affects the textural properties positively. However, it is important that the microwave processing conditions used are chosen appropriately for each food material.
AtıfScopus121WoS99OpenAlex125İncele - MakaleYalnız künye2022Scopus SJRQ2The effect of flours of different immature cereal grains on sourdough and sourdough bread: Microbiological, rheological, textural and sugar profiles
Alkay, Zühal; Yılmaz, Mustafa Tahsin; Can, Aslı Muslu; İspirli, Hümeyra; Dertli, Enes
In this study, the utilization of LAB (Lactiplantibacillus plantarum, Levilactobacillus brevis, Furfurilactobacillus rossiae, Weissella cibaria) cultures with selected flours of different immature cereal grains (wheat, barley, oat and rye) on sourdough and sourdough bread was investigated. In total, 16 different sourdough breads were produced and microbiological, pH, TTA and rheological properties of sourdoughs at 0, 8 and 24 h were determined. At the beginning of the fermentation, while sourdoughs showed elasticity, they showed viscoelastic properties after 24 h of fermentation. The sugar profile of cereal grains at the stage of milk formation and the sugar groups presented in EPSs isolated from sourdoughs were revealed by HPLC analysis. The sugar groups in sourdoughs were glucose, xylose and arabinose, while the sugars in the immature cereal grains were glucose, fructose and mannose. The highest EPS production level (1882.69 ± 8.16) was observed in immature barley flour and Lpb. plantarum containing sourdough and all sourdoughs were found to contain glucan type EPSs. It was observed that the amount of EPS produced by the related species differed significantly under different grain conditions. Besides, it was observed that the sourdough breads produced were harder than the control bread. Novelty Impact Statement: Wheat, barley, oat and rye immature grains and four distinct LAB strains were used during sourdough fermentation. Immature grain type and LAB strain used were determinants for in situ exopolysaccharide (EPS) production. Viscoelastic properties of sourdough and textural properties of sourdough bread were affected by grains and LAB strain utilized.
AtıfScopus5WoS2İncele - MakaleYalnız künye2022Scopus SJRQ3Gram-scale synthesis of (S)-1-(thiophen-2-yl)ethanol in high enantiomeric purity under Enterococcus faecium BY48 biocatalysts
Şahin, Engin
Sulfur-containing chiral heterocyclic secondary alcohols are relevant intermediates in the preparation of enantiomerically pure compounds endowed with biological activity. In this report, we evaluated the reductive potential of different lactic acid bacteria as whole-cell biocatalysts of the enantioselective reduction of 1-(thiophen-2-yl)ethanone (1). Enterococcus faecium BY48, isolated from boza, a cereal-based fermented beverage, was found to be the best biocatalyst in our initial investigations. Using whole-cell preparations of E. faecium BY48, we then systematically analyzed the reaction parameters (pH, incubation period, agitation speed, and temperature) to optimize the yield, the enantiomeric excess (e. e.), and the conversion leading to (S)-1-(thiophen-2-yl)ethanol [(S)-2]. The target derivative, which is a precursor in the synthesis of biologically active chiral compounds, was obtained in enantiomerically pure form, gram-scale amounts, and high yield. This is also the first report that the manufacture of (S)-2 in excellent conversion, yield, enantiopure form, and gram scale used whole-cell biocatalyst. This whole-cell E. faecium BY48 biocatalyzed reaction is a clean, environmentally friendly, and cost-effective process, representing a valuable alternative to chemical catalysis or previously reported biocatalytic procedures in the preparation of (S)-2.
AtıfScopus3WoS3OpenAlex5İncele - MakaleAçık Erişim2022Scopus SJRQ2Probiotic ice cream with Malus floribunda fruit sauce: Quality properties, mineral, and volatile composition
Arslaner, Ayla; Salik, Mehmet Ali
This study investigated the effect of Malus floribunda fruit sauce (MFS) on the quality properties, minerals, volatiles, and viability of Lactobacillus acidophilus La-5® in probiotic ice creams. The MFS increased the dry matter, acidity, total sugar, invert sugar, and calories while decreasing fat, protein, ash, sucrose contents, viscosity, overrun, first dripping, complete melting time, and the pH of samples. The heavy metal contents were within safe limits. The MFS increased the perception of a fruity taste/aroma due to the increase in the terpenes and terpenoids, which reflected positively on the sensory scores. The highest taste and odor score (4.72) was seen in the MFIC sample. L. acidophilus La-5® counts (7.49 log cfu/g) and the survival rate (100.69%) of MFIC were significantly higher at the end of storage. Consequently, MFS may be used as a source of flavoring agents in ice cream and MFIC is a satisfactory vehicle for L. acidophilus La-5®. Novelty impact statement: There is no study in the scientific literature on the use of Malus floribunda fruit sauce (MFS) as a potential functional ingredient in probiotic ice cream production. MFS supplementation caused a significant change of volatile compounds in ice cream samples, which reflected positively on the sensory scores. MFS enhanced survival rates of Lactobacillus acidophilus La-5® in ice creams during the 60 days of storage.
AtıfScopus7WoS6OpenAlex10İncele - MakaleAçık Erişim2022Scopus SJRQ2Assessment of waste-to-energy potential of ELT management: An actual case study for Erzincan
Güngör, Osman; Tozlu, Alperen; Arslantürk, Cihat
End-of-life tires (ELTs) and their decomposition are becoming a major environmental issue in the local region as a result of economic and technological challenges. Despite this, ELT management is gaining popularity as an advanced function for treating tires to obtain char, oil, and gas products using pyrolysis. The main goal of this article is to integrate data from an actual recycling plant with the activities of pyrolysis products and their physical properties in the literature. This article presents energy potentials and basic applications of pyrolysis products as well as advances in the current situation in ELT management in the world. Accordingly, an existing ELT management in Erzincan, Turkey is explained in detail by considering the available energy recovery and material treatment activities. In this plant, which has an installed power capacity of 12 MW, approximately 25 tons of pyrolytic oil, 10.7 tons of pyrolytic gas, 24 tons of carbon black and, 10.4 tons of steel are produced daily. The calorific values of carbon black and pyrolytic oil for the products leaving the pyrolysis plant are close to the values in the literature, which is promising. In the plant, the overall thermal efficiency of the system and the engine is found to be 26.34% and 51.24%, respectively. On the other hand, to supply additional power to the plant utilizing exhaust gas discharged to the atmosphere, some thermodynamic models can be developed; additionally, more rational values can be obtained through thermoeconomic and optimization.
AtıfScopus1WoS2OpenAlex3İncele - MakaleYalnız künye2022Scopus SJRQ2Improvement of corrosion and stress corrosion properties of magnesium alloys by coating aluminum with the electric arc spray method
Catar, Recep; Altun, Hikmet
In this study, corrosion and stress corrosion behaviors of AZ31, AZ61, and AZ91 magnesium alloys coated with aluminum by the electric arc spray method were investigated in 3.5 wt.% NaCl solution. Structural properties of coated materials were investigated by scanning electron microscopy (SEM), energy dispersive X-ray analysis, and X-ray diffraction. Electrochemical properties were determined using the potentiodynamic polarization method in 3.5 wt.% NaCl solution. Potentiodynamic polarization curves showed that corrosion current density values did not change with coating in aluminum-coated samples by the electric arc spray method. In contrast, corrosion potential value increased toward positive values. Slow strain rate test (SSRT) was used to determine the stress corrosion behavior and stress corrosion indexes (ISCC), ultimate tensile strength (UTS), and elongation of AZ31, AZ61, and AZ91 magnesium (Mg) alloys were determined. As a result of the SSRT, the aluminum coating process decreased significantly the stress corrosion indexes of AZ31, AZ61, and AZ91 Mg alloys. The fracture of surface images was also examined in the SEM, and both intergranular and transgranular stress corrosion cracking were observed in all three alloys.
AtıfScopus6WoS5OpenAlex5İncele - MakaleYalnız künye2021Scopus SJRQ3Biocatalytic asymmetric synthesis of (R)-1-tetralol using Lactobacillus paracasei BD101
Kalay, Erbay; Şahin, Engin
Asymmetric bioreduction of ketones is a fundamental process in the production of organic molecules. Compounds containing tetralone rings are found in the structure of many biologically active and pharmaceutical molecules. Biocatalytic reduction of ketones is one of the most promising and significant routes to prepare optically active alcohols. In this study, the reductive capacity of Lactobacillus paracasei BD101 was investigated as whole-cell biocatalyst in the enantioselective reduction of 1-tetralone (1). In biocatalytic reduction reactions, the conversion of the substrate and the enantiomeric excess (ee) of the product are significantly affected by optimization parameters such as temperature, agitation rate, pH, and incubation time. Effects of these parameters on ee and conversion were investigated comprehensively. (R)-1-tetralol ((R)-2), which can be used to treat disorder such as obsessive compulsive, post-traumatic stress, premenstrual dysphoric, and social anxiety, was manufactured in enantiopure form, high yield and gram-scale, using whole-cell biocatalysts of L. paracasei BD101. The 7.04 g of (R)-2 was obtained in optically pure form with 95% yield. Also, to our knowledge, this is the first report on production of (R)-2 using whole-cell biocatalyst in excellent yield, conversion, enantiopure form and gram scale. This is a clean, eco-friendly and cheap method for the synthesis of (R)-2 compared with chemical catalyst.
AtıfScopus23WoS23OpenAlex24İncele - MakaleYalnız künye2021Scopus SJRQ3Regioselective asymmetric bioreduction of trans-4-phenylbut-3-en-2-one by whole-cell of Weissella cibaria N9 biocatalyst
Kalay, Erbay; Şahin, Engin
There is a considerable interest in the asymmetric production of chiral allylic alcohols, the main building blocks of many functional molecules. The asymmetric reduction of α,β-unsaturated ketones is difficult with traditional chemical protocols in a regioselective and stereoselective manner. In this study, the reductive capacity of whole cell of Leuconostoc mesenteroides N6, Weissella paramesenteroides N7, Weissella cibaria N9, and Leuconostoc pseudomesenteroides N13 was investigated as whole-cell biocatalysts in the enantioselective reduction of (E)-4-phenylbut-3-en-2-one (1). The biocatalytic reduction of 1 to (S,E)-4-phenylbut-3-en-2-ol ((S,E)-2) using the whole cell of W. cibaria N9 isolated from Turkish sourdough was developed in a regioselective fashion, occurring with excellent conversion and recovering the product in good yield. In biocatalytic reduction reactions, the conversion of the substrate and the enantiomeric excess (ee) of the product are significantly affected by optimization parameters such as temperature, agitation rate, pH, and incubation time. Effects of these parameters on ee and conversion were investigated comprehensively. In addition, to our knowledge, this is the first report on production of (S,E)-2 using whole-cell biocatalyst in excellent yield, conversion with enantiopure form and at gram scale. These findings pave the way for the use of whole cell of W. cibaria N9 for challenging higher substrate concentrations of different α,β-unsaturated ketones for regioselective reduction at industrial scale.
AtıfScopus21WoS21OpenAlex23İncele - MakaleAçık Erişim2021Scopus SJRQ2Effect of ohmic heating on ultrasound extraction of phenolic compounds from cornelian cherry (Cornus mas)
Kutlu, Naciye; Isci, Asli; Sakiyan, Ozge; Yilmaz, Asim Egemen
In this study, total phenolic compounds (TPCs) from cornelian cherry were extracted by using maceration (ME), ultrasound extraction (UE), and ohmic heating-assisted ultrasound extraction (OAUE) methods. ME was used as a control group. It was observed that the ultrasound was effective on the yield of TPC in extraction and the effect was increased when this method was supported with ohmic heating (OH). The maximum TPC extracted was found to be 7.52 mg GAE/g dry matter (by using OAUE) which was 13% and 37% higher compared with that of obtained by UE and ME, respectively. It was also observed that the ohmic heating application decreased the extraction time by about 34% compared with UE. Moreover, the extracts obtained by OAUE had the highest total monomeric anthocyanin concentration and antioxidant activity. Consequently, the OH application prior to extraction played an active role in both obtaining the valuable compounds and decreasing the extraction time. Practical applications: Cornelian cherry (Cornus mas), which is a natural antioxidant source, contains a significant number of valuable compounds (polyphenols, vitamins, minerals, etc.). Therefore, new extraction methods were used as an alternative to conventional methods (such as maceration) to extract the valuable compounds. It was observed that novel methods such as ultrasound and ohmic heating-assisted extraction had a positive effect to increase extraction yield and saving time. Highly efficient applications (such as ohmic heating) on the extraction of bioactive compounds from food materials open up a new horizon in the food industry.
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