Sürdürülebilir Kalkınma Amaçları

Yazarlar

  • MakaleAçık Erişim2023Scopus SJRQ2
    The contact problem of a functionally graded layer under the effect of gravity

    Adiyaman, Gokhan; Oner, Erdal; Yaylaci, Murat; Birinci, Ahmet

    This paper considers the continuous and discontinuous contact problems of a functionally graded (FG) layer under the effect of gravity. A finite distributed load is applied to the beam from the top and the beam is placed to the top of a rigid foundation. It is assumed that the shear modulus and mass density of the beam vary exponentially whereas Poisson's ratio remains constant. The problem is solved for both continuous and discontinuous cases. In each case, the governing equations and boundary conditions of the problem are reduced to an integral equation by the help of Fourier integral transform. In the continuous contact, the integral equation solved analytically and critical load that causes initial separation between the layer and the rigid foundation, separation distance and contact pressures are investigated for various non-homogeneity parameters that presents the change in the shear modulus and density and loadings. The singular integral equation in case of discontinuous contact is numerically solved by using corresponding Gauss–Chebyshev quadrature and an iterative scheme. The effect of non-homogeneity parameters and loading on the separation distance between the layer and the foundation and contact pressures are analyzed. All the results are shown in tables and figures. It is seen that increasing stiffness and decreasing density at the top of the layer reduce maximum pressures but increase separation distances. This study aims to fill the deficiency in the mechanical behavior of the coatings under gravity.

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  • MakaleAçık Erişim2023Scopus SJRQ2
    The mediating role of time attitude in the relationship between self-esteem and resilience in high school students

    Çelik, Eyüp; Süler, Melek; Söylemez, Aydın; Koçak, Lokman

    The aim of this research was to investigate the mediating role of time attitudes in the relationship between self-esteem and resilience in high school students. High school students’ self-esteem, time attitude, and resilience have been researched comparatively. The research was carried out with a quantitative research design and survey method. Participants, who were selected using a convenience sampling method, were high school students. The 1,932 participants consisted of students in the following grade distribution: 793 ninth grade (248 male, 545 female); 365 tenth grade (78 male, 257 female); 350 eleventh grade (90 male, 260 female); and 434 twelfth grade (130 male, 324 female). Participants were selected from secondary education institutions in Sakarya and Kocaeli during COVID-19 from January to May 2021. Data were collected using tools such as the Two Factored Self-Esteem Scale, Adolescent Time Attitude Scale, and Ego Resilience Scale. The data was analyzed with correlation analysis and regression-based mediation analysis to investigate the relationship between self-esteem, time attitude and resilience. The SPSS 22 package program was used to analyze the data. After analyzing the data, it has been concluded that the time attitude in adolescents indeed has a mediating role in the relationship between self-esteem and resilience. The results of the research will make important contributions to the related literature.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    • SDG 4 · Nitelikli Eğitim
    AtıfScopus5OpenAlex3
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  • MakaleYayıncıda açık erişim2023Scopus SJRQ2
    A randomized controlled trial of reflexology effect after abdominal surgery on patient satisfaction, pain and vital signs

    Kapıkıran, Gürkan; Bulbuloglu, Semra; Gunes, Huseyin; Saritaş, Serdar; Demir, Bilsev

    Objective: In our study, we investigated the effect of reflexology on patient satisfaction, pain and vital signs after abdominal surgery. Method: This study was conducted as a randomized controlled trial with the participation of 156 abdominal surgery patients hospitalized in the general surgery unit of a training and research hospital. Personal Information Form, Visual Analogue Scale and Newcastle Nursing Care Satisfaction Scale were used in data collection. We performed the data analysis with One-way analysis of variance, Chi-squared test, paired samples t-test, and independent samples t-test. Results: When the pain, vital signs and satisfaction levels of the experimental and control groups were compared, the pain intensity of the experimental group was found to be lower and the level of satisfaction was higher after reflexology (p<0.01). After reflexology, the blood pressure was closer to 120/80 in the experimental group, the respiratory rate was between 16-22 (number/minute), the difference between the experimental and control groups were statistically significant (p<0.01). There was no statistically significant difference between the pulce oximetry values between the experimental and control groups. Conclusion: Surgical pain and non-optimal vital signs that are not well managed after surgery causes various complications and decrease patient satisfaction. The results of our study emphasize the power of reflexology in effective surgical pain management and normalizing vital signs and increasing patient satisfaction. We suggest that reflexology be performed to patients following abdominal surgery.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    AtıfScopus8WoS7OpenAlex10
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  • MakaleAçık Erişim2023Scopus SJRQ2
    Evaluation Expression of the Caspase-3 and Caspase-9 Apoptotic Genes in Schizophrenia Patients

    Dirican, Ebubekir; Özcan, Halil; Uzunçakmak, Sevgi Karabulut; Takım, Uğur

    Objective: Apoptosis is programmed cell death that occurs by several pathways. Caspase-3 is induced by active caspase-9 via the intrinsic pathway. The aim of this research was to explore the expression of caspase-3 and caspase-9 in schizophrenia patients and healthy samples. Methods: RNA was isolated from the peripheral blood of 39 schizophrenia patients’ and healthy samples. After cDNA synthesis, real time PCR (RT-PCR) was used to analyse caspase-3 and caspase-9 gene expression. The severity of psychopathological symptoms of schizophrenia was evaluated using the Positive and Negative Symptoms Scale for schizophrenia (PANSS) and Clinical Global Impressions (CGI). Results: The expression of caspase-3 and caspase-9 genes was higher in schizophrenia patients than in healthy samples (p = 0.012, p = 0.002, respectively). The increase in caspase-3 gene expression was significant with being male, smoking and with a duration of less than 6 years (p = 0.047, p = 0.049, p = 0.034, respectively). On the other hand, the increase in caspase-9 gene expression was significant in patients who is smoke, have children, and are under 33 years old (p = 0.040, p = 0.043, p = 0.045, respectively). A significant positive correlation was detected between the caspase-3 and caspase-9 gene expression (r = 0.3218, p = 0.049). Conclusion: Our findings indicate that caspase-3 and caspase-9 gene expression may activate cell death mechanisms by intrinsic apoptotic genes. Furthermore, caspase-3 and caspase-9 may play essential roles in different ways in schizophrenia. Hence there is a need to further study the apoptotic mechanism with expanded patient populations.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    AtıfScopus45WoS47OpenAlex42
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  • MakaleAçık Erişim2023Scopus SJRQ2
    Tourism and FDI-Growth Nexus in Upper-Middle Income Countries: Evidence from Static and Dynamic Panel Analyses

    Soylu, Özgür Bayram; Adeleye, Bosede Ngozi; Okur, Fatih; Emikönel, Murat

    This paper examines the role of tourism in foreign direct investment-growth relations in upper-middle-income countries. We deploy static and dynamic panel analysis to evaluate how tourism indicators influence the impact of FDI net inflows on growth using unbalanced panel data on 29 upper-middle-income countries from 2010 to 2019. The tourism indicators are receipts, arrivals, and expenditures. The results from static and dynamic analyses indicate that for the most part (1) FDI and tourism exert asymmetric effects on growth, (2) tourism indicators reduce the negative effect of FDI on growth, (4) trade openness is a positive and significant predictor of growth, and (5) domestic credit negatively contributes to growth. Deductively, results evidence that tourism indicators are critical drivers of economic growth in upper-middle-income countries. Overall, tourism receipts show the largest influence on FDI to spur the most appreciable impact on growth. Despite this, the fact that tourism indicators cannot eliminate the destructive impact of FDI on economic growth shows that tourism development policies should be based on a greener and more sustainable ground, taking into account the effects of the coronavirus.

    • SDG 8 · İnsana Yakışır İş ve Ekonomik Büyüme
    AtıfScopus8WoS7OpenAlex6
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  • MakaleYalnız künye2023Scopus SJRQ2
    The willingness of elderly care program students to care for older adults and the associated factors: a multi-centered research

    Okur, Elif; Akbal, Yağmur; Yagci Sentürk, Aysun; Daştan, Buket; Kuralay, Çiğdem

    Prospective technicians for elderly care are indispensable elements that should be included in the relevant system to meet the ever-increasing care needs of the aging world population and increase the quality of care. This research was conducted to evaluate the attitudes of students in the elderly care program at the associate degree toward the older adults and their willingness to provide care. The sample of this descriptive and cross-sectional study comprised 525 volunteer students in elderly care programs in five vocational schools of higher education located in northeastern Turkey between June 2020 and September 2020. Mean, standard deviation, number, percentage, independent t-test, and correlation analysis were used to evaluate the data. The study showed that the mean age of the students involved in the study was 20.3 ± 1.6. 77.7% of them were female, and 61.9% were in the first grade. Students’ willingness to care for older adults was found to be at a moderate level (36.3 ± 6.0). The students had a negative attitude (137.4 ± 26.7) about aging and elderliness. The willingness of male students to care for older adults was significantly higher (p <.05). Those who did not live with an older adult in the same house before had a more negative attitude toward them (p <.05). To get rid of personal and social stereotypes and have a positive attitude toward older adults, students should be provided to work in clinical environments that will allow them to spend more time with them.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    • SDG 4 · Nitelikli Eğitim
    AtıfScopus5WoS5OpenAlex9
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  • MakaleAçık Erişim2023Scopus SJRQ3
    Enhancing magnetic levitation and guidance force and weight efficiency of high-temperature superconducting maglev systems by using sliced bulk YBCO

    Abdioglu, Murat; Ozturk, U. Kemal; Guner, Sait Baris; Ozturk, Mehmet; Mollahasanoglu, Hakki; Yanmaz, Ekrem

    We aimed to enhance the magnetic force efficiency of Maglev systems without increasing total weight. For this aim, we divided YBCO bulks into three slices horizontally to utilize the YBCO-permanent magnetic guideway (PMG) interaction surface as much as possible. We used whole YBCO above PMGs with different magnetic pole directions (PMG-A and PMG-B) in two lying positions of transversal and longitudinal and investigated levitation and guidance force performances. It is determined that levitation and guidance forces by using YBCO in transversal lying mode are bigger compared to the longitudinal mode. For sliced YBCO, the maximum levitation force increased by 69% and 78%, while the guidance force enhancements are determined as 212% and 91%, compared to the whole YBCO above PMG-A and PMG-B, respectively. The levitation and guidance force density with respect to the total mass of unit a set of slices YBCO increased by 92% and 106%, respectively, compared to the whole YBCO above PMG-B in transversal mode. Since the higher levitation force and the lower total weight of the onboard unit are important parameters in point of the energy efficiency in Maglev and other levitation applications, the result of this study supplies useful data for the engineers and industrial partners.

    AtıfScopus7WoS7OpenAlex6
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  • Derleme MakaleAçık Erişim2023Scopus SJRQ1
    Recent Insights into the Use of Antagonistic Yeasts for Sustainable Biomanagement of Postharvest Pathogenic and Mycotoxigenic Fungi in Fruits with Their Prevention Strategies against Mycotoxins

    Oztekin, Sebahat; Dikmetas, Dilara Nur; Devecioglu, Dilara; Acar, Emine Gizem; Karbancioglu-Guler, Funda

    Fungi-induced postharvest diseases are the leading causes of food loss and waste. In this context, fruit decay can be directly attributed to phytopathogenic and/or mycotoxin-producing fungi. The U.N. Sustainable Development Goals aim to end hunger by 2030 by improving food security, sustainable agriculture, and food production systems. Antagonistic yeasts are one of the methods presented to achieve these goals. Unlike physical and chemical methods, harnessing antagonistic yeasts as a biological method controls the decay caused by fungi and adsorbs and/or degrades mycotoxins sustainably. Therefore, antagonistic yeasts and their antifungal mechanisms have gained importance. Additionally, mycotoxins’ biodetoxification is carried out due to the occurrence of mycotoxin-producing fungal species in fruits. Combinations with processes and agents have been investigated to increase antagonistic yeasts’ efficiency. Therefore, this review provides a comprehensive summary of studies on preventing phytopathogenic and mycotoxigenic fungi and their mycotoxins in fruits, as well as biocontrolling and biodetoxification mechanisms.

    • SDG 2 · Açlığa Son
    • SDG 12 · Sorumlu Üretim ve Tüketim
    AtıfScopus75WoS62OpenAlex74
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  • MakaleYalnız künye2023
    AN EXAMINATION OF EMOTIONAL AND CREATIVE LEVELS AMONG TERTIARY STUDENTS IN TEAM AND INDIVIDUAL SPORTS

    Çingöz, Yunus Emre; Mavibaş, Muhammet

    The primary objective of this research was to investigate the effect of emotional states on creativity levels tertiary students in team and individual sports. The study further aimed to discern the various emotional states and creativity levels prevalent among athletes, contingent on different variables. The participants comprised 302 athletes, 162 males and 140 females, who were all registered students in the Faculty of Sports Sciences at Bayburt University. In order to gather demographic data, the researchers constructed a “Personal Information Form”. The “Sports Emotion Scale”, developed by Urfa and Aşçı (2019), was utilized to assess the emotional states of the athletes within their respective sports. To evaluate their creativity levels in sports, the “Creativity Scale for Athletes”, constructed by Güngör et al. (2020), was utilized. Data analysis incorporated frequency analysis for determining the participants' demographic attributes, and descriptive tests for establishing the mean scores of both emotional states and creativity levels in sports. The independent t-tests were used to compare emotional and creativity levels based on gender and sport type. One-way ANOVA tests were used to compare emotional and creativity levels based on educational level and years of sports experience. Post-hoc comparisons were facilitated using Tukey tests to identify specific group differences. Lastly, multiple linear regression analysis was applied to scrutinize the impact of emotional states on creativity levels in sports. The research findings indicate that athletes participating in team sports demonstrated higher levels of enthusiasm and happiness, as determined by the sub-dimensions of the Sports Emotion Scale, when compared to athletes participating in individual sports. In addition, it was noted that an increase in feelings of unhappiness among athletes corresponded to a decrease in their levels of sports creativity. Conversely, a surge in enthusiasm was associated with heightened creativity levels within sports.

  • MakaleAçık Erişim2023Scopus SJRQ1
    Exploring the Charge Transport of a Natural Eumelanin for Sustainable Technologies

    Paulin, João V.; Bayram, Sinan; Graeff, Carlos F. O.; Bufon, Carlos C. B.

    Eumelanin, the main quinone-based biomaterial of the melanin family of compounds, is emerging as a model for medical and sustainable electronic interfaces due to its biocompatibility, biodegradability, and transducing abilities. The study utilizes current-voltage measurements and impedance/dielectric spectroscopy under a controlled hydration atmosphere to investigate the charge transport of eumelanin produced from the S. parvus BSB49 strain. We show no differences in the electrical response in highly hydrated conditions compared to the standard synthetic eumelanin. Hence, our findings provide the groundwork to assess the potential use of this natural eumelanin in sustainable organic (bio)electronic applications.

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  • MakaleAçık Erişim2023Scopus SJRQ2
    Characterization of Bee Bread Produced with Defined Starter Cultures Mimicking the Natural Fermentation Process

    Poyraz, Fatmanur; Yalmanci, Dilara; İspirli, Hümeyra; Dertli, Enes

    Bee bread is a product with unique properties for humans and bees that is produced through the fermentation of pollen in the honeycomb, mainly caused by lactic acid bacteria (LAB) and yeast strains present in the environment. It is a rich source of nutrients such as proteins, polyphenols and vitamins. Despite the potential nutritional value of bee bread, it is consumed at low levels, as harvesting bee bread from the hives is costly and difficult. This study aimed to produce a standard bee bread by using different strains of the fructophilic lactic acid bacteria (FLAB) Lactobacillus kunkeei and the yeasts Starmeralla magnolia MP-2 and Zygosaccharomyces siamensis MP-14, previously isolated from bee products. In this context, bee bread was produced from pollen by solid-state fermentation using selected FLAB and yeast species, which were then compared with spontaneously developed and commercially available bee bread in terms of microbial stability, physicochemical properties, total phenolic component amounts, in vitro digestibility and amino acid profiles. As a result, it was determined that bee bread made from bee pollen fermented with starter cultures showed improved characteristics than commercial bee bread and was more advantageous in terms of absorption as well as production processes.

    • SDG 2 · Açlığa Son
    AtıfScopus19WoS17OpenAlex18
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  • MakaleAçık Erişim2023Scopus SJRQ2
    Contribution of Oxidative Stress, Apoptosis, Endoplasmic Reticulum Stress and Autophagy Pathways to the Ameliorative Effects of Hesperidin in NaF-Induced Testicular Toxicity

    Emre Kızıl, Hamit; Gür, Cihan; Ayna, Adnan; Darendelioğlu, Ekrem; Küçükler, Sefa; Sağ, Sevda

    The ameliorative effects of hesperidin (HES) on the toxicities created by sodium fluoride (NaF) in the testes tissue of rats were studied via oxidative stress, apoptosis and endoplasmic reticulum (ER) stress pathways. The animals were divided into five distinct groups (7 rats in each group). Group 1 was control group, group 2 received NaF-only (600 ppm), group 3 received HES-only (200 mg/kg bw); group 4 received NaF (600 ppm)+HES (100 mg/kg bw) and group 5 received NaF (600 ppm)+HES (200 mg/kg bw) for 14 days. NaF-induced testes tissue damage by reducing activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and levels of glutathione (GSH), and increasing lipid peroxidation levels. NaF treatment significantly downregulated the mRNA levels of SOD1, CAT and GPx. NaF supplementation caused apoptosis in the testes by upregulating p53, NFkB, caspase-3, caspase-6, caspase-9, and Bax and downregulating Bcl-2. Furthermore, NaF caused ER stress via increasing mRNA transcript levels of PERK, IRE1, ATF-6 and GRP78. NaF treatment led to autophagy via upregulation of Beclin1, LC3A, LC3B and AKT2. In testes tissue, however, co-treatment with HES at doses of 100 and 200 mg/kg significantly reduced oxidative stress, apoptosis, autophagy and ER stress. Overall, the findings of this study suggest that HES may help to reduce testes damage caused by NaF toxicity.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    AtıfScopus49WoS46OpenAlex47
    ScopusWeb of SciencePubMedİncele
  • MakaleAçık Erişim2023Scopus SJRQ1
    Palynological, chemical, antimicrobial, and enzyme inhibition properties of Cannabis sativa L. propolis

    Özkök, Aslı; Karlıdağ, Semiramis; Keskin, Merve; Bayram, Sinan; Keskin, Şaban; Karabulut, Ercan; Çiçek, Fevzi; Yılmaz, İsmet

    In this study, both chemical characterization and biological activities of propolis samples obtained from Cannabis sativa L. (cannabis, hemp, marijuana) isolated colonies (research group) and obtained from colonies at a distance where the bee cannot fly to the isolation area (control group) were determined. Palynological analyses of propolis samples obtained from the research and control group colonies were made and the botanical origin of the cannabis plant and other plants in the research area and the plants in the control group were determined. Bioactive component analysis of propolis extracts was determined by the GC–MS technique. The inhibition effect of propolis samples on some enzymes of medical importance and their antimicrobial effects against many pathogenic microorganisms were also investigated. Palynological analyses showed that honey bees prefer cannabis plants (11.11%) when collecting propolis, and the dry matter percentage (94.6 ± 1.8%), balsam (46.2 ± 5.2%), and wax content (4.8 ± 0.5%), total phenolic (26.44 ± 1.08 mg GAE/mL) and total flavonoid (2.03 ± 0.11 mg QE/mL) content and antioxidant capacity (88.16 ± 2.27 μM FeSO4·7H2O/mL−1) of the research group propolis samples containing hemp were found to be higher than the control group. Also, it was determined that the research group propolis sample contains cannabinoid derivatives (cannabidivarinic acid, 0.29%; delta (1)-tetrahydrocannabinolic acid, 0.59%; cannabidiolic acid, 0.48%), which are active compounds of the cannabis plant. Also, a high inhibition effect was detected on some enzymes of medical importance in propolis samples obtained from cannabis group colonies. In addition, the research group propolis samples also showed a high antimicrobial effect against many pathogenic microorganisms.

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  • MakaleAçık Erişim2023Scopus SJRQ2
    Thermal, rheological, and mechanical characterization of compression and injection molded ultra-high molecular weight polyethylene, high density polyethylene, and their blends

    Yang, Huaguang; Yilmaz, Galip; Jiang, Jing; Langstraat, Thomas; Chu, Raymond; van Es, Martin; Garg, Priya; Turng, Lih-Sheng

    Tensile and impact test samples of ultra-high molecular weight polyethylene (UHMWPE), high-density polyethylene (HDPE), and their blends at various UHMWPE/HDPE weight ratios were prepared via compression molding and injection molding for thermal, rheological, and mechanical characterization. A twin-screw extruder with either a tapered die with air-cooling or a regular die was used to compound and extrude the materials prior to pelletization and molding. To the best of our knowledge, there has been no publication on pelletizing neat UHMWPE using a regular extruder. The differential scanning calorimetry analysis suggested the occurrence of re-crystallization and co-crystallization for all the blends. The rheology test confirmed that all the blends exhibited a solid-like behavior and the degree of compatibility increased with increasing HDPE content in the blends. A strong synergistic effect was observed the blends possessed a higher tensile and impact strength than their neat UHMWPE and HDPE counterparts. The compression molded (95/5) UHMWPE/HDPE samples extruded using the tapered die yielded the highest tensile strength (50.1 MPa), which was about 40% higher than that of the neat UHMWPE samples. The best composition of these blends for compression and injection molded parts is 10% HD and 50% HD, respectively.

    AtıfScopus13WoS13OpenAlex14
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  • MakaleYalnız künye2023
    EXAMINING COGNITIVE STRUCTURES OF SECONDARY SCHOOL STUDENTS REGARDING CONCEPTS RELATED TO MULTICULTURAL EDUCATION

    Yılmaz, Sevda

    The aim of this study was to investigate the cognitive structures of secondary school students regarding concepts related to multicultural education. The study was conducted through a survey design. The study group consisted of 189 eighth-grade students studying in secondary school. Out of the 189 participants, 97 were female and 92 were male. The criterion sampling method, one of the purposeful sampling methods, was used in the selection of the study group. Word Association Test was used as a data collection tool for the research. According to results of the study, it was determined that secondary school students associated the most words with the concept of culture and the fewest words with the concept of respect. In addition, it has been determined that there is a misconception in the cognitive structures of the students regarding the perceptions of justice and equality. The research results has also shown that the students only weakly correlated concepts related to multicultural education.

  • MakaleYalnız künye2023Scopus SJRQ3
    Modified distance optimization method for the asymmetric bioreduction conditions of phenyl(thiophen-2-yl)methanone by Weissella paramesenteroides N7

    Özdemir, Akın; Şahin, Engin

    Chirality plays a significant part in life since it is closely linked to carrying out the many metabolic processes that make up a living being. Chiral secondary alcohols such as diaryl-, aryl heteroaryl-, and diheteroaryl are employed in pharmaceuticals as drug intermediates. Although biocatalytic asymmetric reduction of prochiral ketones containing aromatic and heteroaromatic groups is widely known, biocatalytic reduction of heteroaromatic prochiral ketones containing sulfur heteroatoms is rarely known. Very few studies exist in the literature, including the biocatalytic reduction of phenyl(thiophen-2-yl)methanone (1). Moreover, the biocatalytic reduction of 1 with a mathematical modelling and optimization technique is unknown until now. In this study, Weissella paramesenteroides N7 biocatalyst for the asymmetric bioreduction of 1 using a novel modified distance optimization method. Optimization conditions were found as pH = 6.46, temperature = 26 °C, incubation period = 71 h, agitation speed = 200 rpm by the modified distance optimization method, and it was determined that the conversion and enantiomeric excess (ee) under these conditions could be 98.7% and 98%, respectively. Under these proposed optimization conditions, (S)-phenyl(thiophen-2-yl)methanol ((S)-2) was obtained with >99% ee, >99% conversion, and 97% yield. In addition, 11.29 g of 1 was completely converted into (S)-2 (11.07 g, 97% isolated yield) under optimized conditions. This is the first report about the fabrication of enantiopure (S)-2 in high gram scale using a biocatalyst and a novel modified distance optimization technique. In this study, the successful applicability of the new modified distance optimization method in biocatalytic asymmetric reduction reactions has been successfully demonstrated.

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  • MakaleAçık Erişim2023Scopus SJRQ3
    Numerical investigation of the Mode I/Mode II fracture behavior of the hybrid composite joints with a hybrid bondline

    Erbayrak, Engin

    In this study, the fracture behavior of fracture characterization bonded joints consisting of hybrid composite adherends and hybrid bondlines under Mode I and Mode II loadings were investigated numerically. Numerical analysis was performed using LS-DYNA. Hybrid composite laminates (HCGFRE) obtained by sequencing plain woven glass fiber reinforced epoxy (GFRE) and plain woven carbon fiber reinforced laminates (CFRE) as adherends. Araldite AV138M and Araldite 2015 epoxy adhesives were also used to create the hybrid bondline. Mode I and mode II fracture behaviors were determined by numerical modeling of the Double Cantilever Beam (DCB) and End Notched Flexural (ENF) tests, respectively. In the numerical model, firstly, the fracture parameters of the relevant adhesives were found in the literature, and verification was made utilizing the numerical model. Then, the fracture behavior in both two modes was examined by forming a hybrid bondline. In the literature, there are restricted studies examining the fracture behavior of fracture characterization bonded joints with hybrid bondlines. Additionally, it is not encountered any study determining the both mode I and mode II fracture behavior of composite fracture characterization bonded joints with hybrid bondlines. Therefore, it is thought that this study will gain significant novelties to the existing literature.

    AtıfScopus1OpenAlex2
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  • MakaleAçık Erişim2023Scopus SJRQ1
    An extensive survey on radiation protection features of novel hafnium iron-borophosphate glasses: Experimental and theoretical study

    Şakar, Erdem; Alım, Bünyamin; Ertap, Hüseyin; Karabulut, Mevlut

    This study aimed to determine the radiation (photon and particle) attenuation abilities of Hf added iron-borophosphate glasses considered as a candidate host matrix for Pu containing nuclear waste. Experimental absorption parameters were measured using 133Ba radionuclide for photon radiation, and the same parameters were theoretically calculated using Phy-X/PSD. The obtained data were evaluated comparatively for all glasses depending on the Hf and B contents. It has been determined that all of the glasses examined have photon absorption ability at a level that can be a shielding material for nuclear applications. In addition, the interaction cross-sections with particle radiations were computed using SRIM and ESTAR software. When the data obtained are evaluated thoroughly, it can be said that investigated glasses can be used as shielding in areas that require protection from both photon and particle radiation, in addition to being a candidate material for the vitrification of nuclear wastes containing Pu.

    AtıfScopus5WoS6OpenAlex8
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  • Derleme MakaleAçık Erişim2023Scopus SJRQ2
    A Meta-Analytic Review of the Effect of Socioeconomic Status on Academic Performance

    Selvitopu, Abdullah; Kaya, Metin

    The two main purposes of the current meta-analysis were (a) to determine the relation between socioeconomic status (SES) of students and academic performance (AP) (b) and evaluate the effect of several potential moderating factors in this relation. Data covered the publications between 2010 and 2019, and the dataset consisted of 48 independent studies that included 62 different samples, and the total sample was 386.601. Findings revealed that the relation between SES and academic performance represented a moderate positive correlation. All moderators, type of SES measure, academic performance scale, location, grade level, subjects of academic performance, and year, produced significant effects, respectively. These findings were discussed for every category of moderators with the related literature.

    • SDG 4 · Nitelikli Eğitim
    • SDG 10 · Eşitsizliklerin Azaltılması
    AtıfScopus65WoS54OpenAlex81
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  • MakaleAçık Erişim2023Scopus SJRQ1
    Optimizing the seismic resilience performance of steel truss bridges by maximum energy dissipation via friction dampers

    Artar, Musa; Carbas, Serdar

    The primary aim of this study is to propose an innovative design methodology for optimizing the seismic resilience performance of steel truss bridges by dissipating the maximum input seismic energy. Maximum seismic energy dissipation is carried out by means of Pall friction dampers (PFDs), popularly categorized among passive energy-damping devices. PFDs distribute input seismic energy with a slip motion along with friction during an earthquake. For that, it is important to determine the optimal slip load value for the PFDs to start working before the structural elements reach the yield point. To determine the optimal slip load values of the PFDs under earthquake effects, the maximum seismic energy distribution is assured by nature-inspired Squirrel Search (SS) and Water Strider (WS) metaheuristic algorithms for steel truss bridges equipped with PFDs. Finally, steel truss bridges on which PFDs with optimal slip load values have been implemented are optimally designed to achieve the minimal structural weight while satisfying ASD-AISC Code of Practice requirements. In order to demonstrate the validity of the proposed design methodology, two design examples of 113-member and 465-member steel truss bridges steel are presented. The optimal slip loads attained with the SS and WS algorithms by conducting the proposed design methodology are 2.45% and 3.75% of the structural weight for the first design example and 2.64% and 2.63% of the structural weight for the second design example, respectively, which are much lower than those considered in practical applications. Moreover, the numerical results show that by 93.5% and 99.48% maximum distribution rates of input seismic energy are accomplished in the bridges. The results indicate that the proposed design methodology exhibit superior performance in optimizing the seismic resilience performance of steel truss bridges by maximum energy dissipation via friction dampers.

    • SDG 9 · Sanayi, Yenilikçilik ve Altyapı
    • SDG 11 · Sürdürülebilir Şehirler ve Topluluklar
    AtıfScopus8WoS4OpenAlex5
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