Yayınlar
Koleksiyondaki öğeler
- MakaleYayıncıda açık erişim2025Scopus SJRQ1Chrome waste utilization in base layers: Mechanical strength and environmental risk assessment
Seferoğlu, Mehmet Tevfik; Acı, Elif Nur
This study investigates the partial substitution of natural aggregate (Na) with chrome mine waste (Crw) in highway base layers, focusing on mechanical performance and environmental safety. Crw-Na mixtures with contents from 0 % to 100 % were tested using CBR, cyclic plate loading, chemical, and leachate tests. The 15 % Crw-85 % Na mixture achieved the highest CBR (287.4 %) with limited deformation (37 mm). Although the 60 % Crw blend also met the required strength level (156.6 %), it showed higher settlement (50 mm) and three times greater vertical strain. SEM-EDX and chemical results indicated increased magnesium content and mineral changes at higher Crw ratios. Leachate tests confirmed compliance with TS266 and international water standards; all samples were categorized as neutral drainage with low metal risk. The findings show that Crw improves strength without causing environmental risk. Among tested mixtures, 15 % Crw offered the most balanced outcome in terms of field stability and performance.
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İncele - MakaleYalnız künye2025Scopus SJRQ2A Novel Numeric-analytic Method for Time-fractional Swift–Hohenberg (S–H) Equation with Modified Caputo-Fabrizio Derivative
Şahin, Yasin; Merdan, Mehmet
This work investigates utilizing Adomian decomposition technique (A-ADM) coupled with Aboodh transform as a hybrid approach the solution of Caputo-Fabrizio (CF) fractional order Swift-Hohenberg problem. Effective framework for modeling memory effects and complex system dynamics is provided by CF fractional derivative defined by non-singular exponential kernel. Classical Swift-Hohenberg equation is expanded to account for long-term memory effects, which are crucial in understanding pattern development and chaotic behavior in many physical systems by including CF fractional derivatives. With the suggested Aboodh-Adomian decomposition technique (A-ADM), an approximate analytical solution is provided showing its efficiency and accuracy in solving fractional nonlinear problem. Furthermore shown are convergence and originality of the solution. Graphical depictions of the acquired solutions make use of MATLAB package software. Theoretical results are confirmed by numerical simulations, which further expose the important influence of fractional order on the dynamic features of the system.
AtıfScopus2WoS2OpenAlex1İncele - MakaleYalnız künye2025Scopus SJRQ2Mantle genesis and crustal contamination in Carboniferous granitoids using U-Th-K concentrations at the Akşar Pluton in the Eastern Pontides, NE Türkiye
Maden, Nafız; Gücer, Mehmet Ali; Akaryalı, Enver
New radiogenic heat production (RHP) data are presented for Carboniferous granites outcropping in the Akşar region (Bayburt, NE Turkey) to contribute to ongoing debates on the genetic and lithologic relationship between the Akşar and Gümüşhane plutons, which is the most widely distributed granitic rocks in the region. The scope of this study consists of rocks composed of enriched mantle material metasomatized by fluids from the previously subducted plate. We observed average K value for the Akşar Pluton was found to be 3.09 ± 1.58 %. Additionally, average Th/U and U/Th values of 3.95 ± 1.37 and 0.29 ± 0.10, respectively. The calculated RHP value for the Akşar Pluton was 2.20 ± 0.56 μWm−3. Numerical results suggest that the Carboniferous Akşar pluton's primary magma was the product of mixing lithospheric mantle and mid-to-lower crustal melts because of partial melting, differentiation, and emplacement in the shallow continental magma chamber. The geochemical and petrogenetic characteristics of the Akşar region magmas suggest that crustal contamination occurred at multiple levels, particularly within the lower to middle crust of the plutonic core complex. This complex likely retains geochemical signatures indicative of subducted Paleotethys oceanic lithosphere. These findings provide critical insights into the magmatic evolution of the Eastern Pontides, contributing to a more comprehensive understanding of crust–mantle interactions and the broader geodynamic framework of northeastern Türkiye.
- MakaleAçık Erişim2024Scopus SJRQ4Spatial Analysis of Economic Risk, Economic Freedom Index, Corruption Perceptions Index and Human Development Index; [Ekonomik Risk, Ekonomik Özgürlük İndeksi, Yolsuzluk Algısı İndeksi ve İnsani Gelişim İndeksi’nin Mekânsal Analizi]
Kalkan, Yusuf
This study aims to examine the spatial (neighbourhood) relations of 163 countries in terms of economic risk (ER), economic freedom index (EFI), corruption perception index (CPI) and human development index (HDI). Moran I, Geographically Weighted Regression (GWR) and Multiscale Geographically Weighted Regression (MGWR) methods were used for spatial analysis. The MGWR models demonstrated that countries globally have strong spatial relationships with their neighbouring countries regarding ER, EFI, and CPI but are not significant regarding HDI. This result can be explained by the fact that ER, EFI and CPI indicators are mostly related to the country's economy and that countries have become economically interdependent today. However, HDI may not have resulted in significant spatial relationships due to its focus on human quality of life and social-cultural differences among countries.
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İncele - MakaleAçık Erişim2025Scopus SJRQ1Optimizing control strategies for DC-DC boost converters: Real-time application of an adaptive gain scheduled ISA-PI controller with hybrid state-space and linear parameter-varying modelling
Yanarateş, Cağfer
This paper introduces an innovative sophisticated control scheme for a DC-DC boost converter (DCBC), employing an adaptive gain scheduled ISA-PI controller. Addressing the inherent non-minimum phase behaviour arising from a right-half plane zero and the complexities associated with nonlinear dynamics during continuous conduction mode (CCM), the proposed adaptive gain scheduled ISA-PI controller incorporates the distinct adjustable parameter within the controller structure. This parameter is instrumental in enhancing the adaptability of the controller to varied operating conditions. The adaptive ISA-PI controller seamlessly integrates the real-time duty cycle value, replacing traditional tuning variables with precision. The dynamic adjustment of this sole controllable parameter is facilitated through a carefully designed look-up table, employing the loop-shaping method. Verification of the proposed control system’s effectiveness is conducted using MATLAB/Simulink, incorporating a comprehensive comparative analysis against single proportional integral (PI) controllers. The assessment centres on evaluating the system’s precision in tracking desired signals and regulating plant process variables with optimal efficiency, minimizing delays and overshoot. Experimental validation is further undertaken using MATLAB/Simulink/Stateflow on a dSPACE Real-time-interface (RTI) 1007 processor, DS2004 High-Speed A/D, and CP4002 Timing and Digital I/O boards. The experimental results confirm the superior performance of the proposed adaptive gain schedule ISA-PI controller, which has a unique configurable parameter. This controller demonstrated a twofold improvement in tracking speed and significantly improved disturbance rejection, confirming its effectiveness.
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İncele - MakaleYalnız künye2019Scopus SJRQ1Theoretical investigation on combustion characteristics of ethanol-fueled dual-plug SI engine
Altın, İsmail; Bilgin, Atilla; Sezer, İsmet
In this study, effects of equivalence ratio, spark timing and spark plug number and locations on combustion characteristics were theoretically investigated using an ethanol-fueled dual-plug SI engine. Two-zone quasi-dimensional model was used throughout analyses. Three spark plug configurations (diagonally, centrally and side located), three equivalence ratios (0.8, 0.9, and 1.0), and three spark timings (−30, −25, and −20 CA @ BTDC) were considered to analyze variation of total burn duration, mass fraction burned, cylinder pressure, and temperatures (exhaust and maximum burned gas). Variation of mass fraction burned and cylinder pressure were also investigated at lean mixture ratio and 2800 rpm (MBT engine speed). Lastly, the effect of engine speed on total burn duration, maximum cylinder pressure and aforementioned temperatures were investigated in the range of 1000–6000 rpm. The findings show that dual-plug configuration yields approximate combustion characteristics by comparison with centrally located single plug configuration in ethanol-fueled SI engine.
AtıfScopus30WoS27OpenAlex28İncele - MakaleAçık Erişim2025Scopus SJRQ1The relationship between CO2 emissions, renewable energy and economic growth in the US: evidence from symmetric and asymmetric spectral granger causality analysis
Zuhal, Mustafa; Göcen, Serdar
This study analyzes the relationship between renewable energy consumption, CO2 emissions, and economic growth for 1973:M01-2022:M06 in the USA. The study employs Spectral Granger Causality analysis symmetrically and asymmetrically. The symmetric causality test presents a bidirectional causality relationship between CO2 emissions, renewable energy consumption, and economic growth. Regarding asymmetric causality results, there is bidirectional causality between positive and negative shocks of CO2 emissions, renewable energy consumption, and economic growth. The results suggest that renewable energy consumption is essential in increasing sustainable economic growth and environmental quality for the USA.
AtıfScopus20WoS17OpenAlex23İncele - MakaleAçık Erişim2025Scopus SJRQ4Life Satisfaction and Subjective Well-Being on the Road to Happiness: An Application of Structural Equation Modeling; [Mutluluğa Giden Yolda Yaşam Doyumu ve Öznel Zindelik: Bir Yapısal Eşitlik Modeli Uygulaması]
Somoğlu, Mustafa Barış; Yazici, Ömer Faruk; Paktaş, Yakup; İşbilir, Emine
This study aims to examine the relationships between happiness, life satisfaction, and subjective vitality among student-athletes. Conducted using a correlational survey design, the research included a total of 400 students (149 female and 251 male; Mean age = 21.31 ± 2.32) enrolled in sports sciences programs across three different universities. The data collection tools utilized were the “Subjective Happiness Scale (SHS),” the “Subjective Vitality Scale (SVS),” and the “Life Satisfaction Scale (LSS).” The suitability of the data for analysis was assessed based on skewness and kurtosis values. Data analysis was performed using IBM AMOS V25 software (Chicago, USA), and the relationships between happiness, life satisfaction, and subjective vitality were tested through Structural Equation Modeling (SEM). According to the results of the structural equation model, the path coefficients between vitality, life satisfaction, and happiness were found to be significant. In this context, life satisfaction explains 44% of subjective happiness, while subjective vitality accounts for 54% of. Based on this, it can be suggested that increasing individuals' levels of life satisfaction and subjective vitality may also enhance their levels of happiness.
AtıfScopus5WoS5OpenAlex3İncele - MakaleAçık Erişim2024Scopus SJRQ1The Status of University Business Schools Regarding Industry 4.0: From the Turkish Perspective
Ilhan-Nas, Tulay; Saglam, Aysegul; Okan, Tarhan; Peker, Iskender
Industry 4.0, whose effects have been more and more noticeable in recent years, and the digital change it brings call for a new educational model that aligns university instructional processes and curricula with the demands of business. This approach, known as University 4.0, intends to promote more technology-based applications, the power of innovation, the training of skilled specialists to satisfy industrial needs, and the development of competences that can achieve multidisciplinary projects. It is of utmost importance to adapt late-industrializing nations’ educational systems, such as Turkey’s, to this change process. The aim of this research, which takes the Turkish context as a reference, is to reveal how the curricula and educational processes of business schools should be shaped with a perspective that takes into account the human resources requirements of industry 4.0. A decision-making technique that integrates QFD, Delphi, and DEMATEL methods was employed in the study. The results clearly show that the most important expectation for social stakeholders is to provide university-industry cooperation. However, some of the most pressing problems include applied learning through collaborative educational experiences, teamwork skills, changing roles and competencies of academics. The findings point out that the educational activities of business schools must be linked with industry expectations through technology-based training activities and teamwork.
AtıfScopus4WoS4OpenAlex5İncele - MakaleAçık Erişim2025Scopus SJRQ1External Costs of Road Traffic Accidents in Türkiye: The Willingness-to-Pay Method
Topcu, Rahmi; Coruh, Emine
Traffic accidents remain a major global burden, causing mortality, disability, and socio-economic losses that hinder sustainable development. Beyond human suffering, crashes place long-term pressures on health systems, labor markets, and national economies, disproportionately impacting low- and middle-income countries. Estimating the true societal costs of accidents is therefore essential for designing effective, equitable, and sustainable road safety policies. This study applies the Willingness-to-Pay (WTP) method to evaluate the external costs of traffic-related deaths and injuries in Türkiye between 2008 and 2018. By incorporating material and immaterial losses, the WTP framework captures a broader spectrum of impacts than traditional approaches, offering valuable insights into the scale of welfare losses and the value of risk reduction. The findings reveal that external costs rose substantially over the decade, from 1.63% to 2.72% of national Gross Domestic Product (GDP), underscoring that economic losses from road crashes are growing faster than the economy. These results highlight the need for systematic interventions that integrate road safety into national sustainability agendas, including safer infrastructure, behavioral programs, advanced vehicle technologies, and efficient emergency response systems. The evidence presented strengthens the case for prioritizing traffic safety as a fundamental component of sustainable transport and public health strategies.
AtıfScopus3WoS2OpenAlex4İncele - MakaleAçık Erişim2024Scopus SJRQ33D reconstruction of foot metatarsal bones of women using CT images
Reis, Hatice Çatal
Bone morphology is a fundamental factor in human anatomy. However, foot and ankle bones have yet to be adequately evaluated in 3-dimensional. It is essential to present the biometric data of anatomical structures. This study formed 3D models of the metatarsal bones of the feet of young women using image processing techniques to examine biometric measurements and determine morphology on these 3D models. This study investigated bone lengths in the metatarsal bones of women feet in Türkiye. A total of ten young female subjects were included as the test group to measure the lengths of their foot metatarsal bones using CT (Computed Tomography) scans, and 20 feet (left/right) were examined. The parameters that were used for the analyses were detector collimation of 64x0.5 mm, section thickness of 0.5 mm, current of 100 mA, tube voltage of 120 kVp, and pixel spacing of 512x512 pixels with a monochrome resolution providing 16-bit gray levels. CT images were processed, and a 3D metatarsal reconstruction was gathered. Then, the biometric measurements were calculated on this 3D model. For the lengths of the volunteers' right/left foot metatarsal bones, statistically significant differences were calculated using a one-sample t-test. For the female metatarsal bones of the left and right feet, statistically significant differences in length were calculated on 3D models. The mean results of the metatarsal length measurements were MT1(metatarsal): 59.52±1.42 mm, MT2: 70.45±1.82 mm, MT3: 66.25±1.82 mm, MT4: 65.12±1.81 mm and MT5: 63.63±1.81 mm. The level of statistical significance was accepted as p <0.05 for the one-sample t-test conducted for each metatarsal bone. The lengths of the right foot metatarsal bones were different from those of the left foot metatarsal bones in the sample. However, this difference was approximately one-tenth of a millimeter. The shortest bone was MT1, and the longest bone was MT2. These measurements are consistent with the anatomical information in the literature. The 3D models from the CT images and the biometric measurements of the metatarsal bones were found to be reliable and accurate.
AtıfScopus1OpenAlex1İncele - MakaleYalnız künye2024Scopus SJRQ1Waste Heat and Mass Recovery from Boiler Exhaust Gases in a New Generation District Heating System: Energy and Exergy Analysis
Terhan, Meryem
The study performs energy and exergy analyses for each component such as boilers, buildings, distribution networks and heat exchangers of a new generation district heating system. Energy and exergy efficiencies are compared for all system components, and energy and exergy losses are presented using Sankey and Grassman diagrams. Three flue gas condensers with finned bundles are designed for different capacities of boilers that intend to recover water and heat from the waste flue gas in the district heating system due to high flue gas energy losses. Colburn-Hougen and one-dimensional finite difference methods are used to design the flue gas condensers with the MATLAB program. The exergy analysis showed that the exergy input to the system is lost by 4.52% from the distribution networks, 4.15% from all buildings and 2.18% from the flue gas. In the system, the energy and exergy efficiencies of the boilers are calculated to be 87.23% and 17.32%, respectively, and the heat loss from the flue gas is found to be 12%. The design results show that the values of mass convection coefficient (km) for all flue gas condensers decrease from 0.0706 at the inlet condensation zone to 0.0354 towards the outlet. The total condensation rate and condensation efficiency are found to be 86 kg/h and 60%, respectively, for the 2500 kW boiler.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2024Scopus SJRQ2The effectiveness of nurses’ psychosocial interventions for sensory deprivation in intensive care patients: a systematic review and meta-analysis
Uzun, Sevda
Objective: This systematic review and meta-analysis aimed to assess the effectiveness of nurses’ psychosocial interventions for addressing sensory deprivation in intensive care units (ICUs). Materials and methods: A comprehensive search of PubMed, Web of Science, EBSCOhost, Google Scholar, CİNAHL, Embase, Cochrane Library, and YÖK Thesis Center databases was conducted from August 2023 to May 2024, without any temporal restrictions. In addition, a physical search was made in the university library for grey literature. Results: The study revealed that nurses’ psychosocial interventions significantly improved patients’ level of consciousness (SMD = 1.042, %95 CI = 0.716 to 1.369; Z = 6.25; p <.05) and sleep quality in ICUs (SMD=1.21, 95% CI= 0.232 to 1.810; Z = 2.49; p <.05). The effectiveness of psychosocial interventions varied based on the type of intervention, patient age, ICU type, patient group, and intervention duration. Notably, auditory stimuli and aromatherapy demonstrated particularly high effect sizes, significantly enhancing patients’ levels of consciousness and sleep quality. Conclusion: In conclusion, psychosocial interventions aimed at reducing sensory deprivation in intensive care units exert beneficial effects on individuals, notably enhancing their level of consciousness and improving sleep quality.
AtıfScopus5WoS4OpenAlex6İncele - MakaleAçık Erişim2024Scopus SJRQ1Effect of PGV/PGA ratio on seismic-induced vibrations of structures equipped with parallel tuned mass dampers considering SSI
Araz, Onur
Tuned mass damper is one of the effective methods used to reduce dynamic loads in structures under the influence of environmental loads such as earthquakes, wind, and traffic loads. In the current TMD design, the fixed base approach is mostly considered when determining the dynamic properties of the structure. However, in cases where the structure-soil interaction (SSI) is important, the frequency values of the structure are significantly different from those obtained for the fixed foundation approach. This situation negatively affects the performance of TMD operating in a narrow frequency range. Therefore, using a control system consisting of multiple TMDs connected in parallel (MTMD) instead of a single TMD may be a promising solution for the control of structural vibrations. In this study, a parameter design and efficiency assessment of MTMD for reducing the seismic responses of the structure considering SSI is studied. The particle swarm optimization (PSO) algorithm is adopted to obtain the optimum parameters (i.e., damping ratio, frequency ratio, and frequency bandwidth) of the MTMD. The effects of different support conditions, number of TMD units, and peak ground velocity (PGV) / peak ground acceleration (PGA) ratio on the performance of MTMD are also evaluated comprehensively. The dynamic responses of the structure are obtained under 42 near -fault ground motions from the time history analysis. The results reveal that ground motions with low PGV/PGA ratio can significantly increase the responses of the structure for both with and without SSI cases. Moreover, it has been observed that optimized TMDs placed parallel to the top floor of the structure are effective in reducing the seismic responses of a ten-story building considering SSI.
AtıfScopus35WoS33OpenAlex31İncele - MakaleAçık Erişim2024Exploring the Impacts of Angelica purpurascens Extracts on Anticholinergic, Antidiabetic, Antibacterial Potential, and Antioxidant Capacity
Topal, Meryem; Topal, Fevzi; Yilmaz, Fırat
In Kars-Sarıkamış-Soğanlı, Angelica purpurascens (A. purpurascens) emerges as a promising natural antioxidant source. Extracts from its leaves, branches, and flowers underwent thorough bioanalytical assessments. The leaf extract exhibited the highest concentrations of herbal flavonoids (45.22 µg QE/mg extract) and total phenolics (28.96 µg GAE/mg extract). Branch extracts demonstrated significant enzymatic activity against AChE and BChE with IC50 values of 37.26 mg/mL and 9.08 mg/mL respectively. The flower extract displayed notable antibacterial properties. This study sheds light on the therapeutic potential of A. purpurascens ethanol extracts, suggesting benefits for Alzheimer’s, cell damage-induced diseases, and diabetes mellitus. It pioneers new enzymatic and antioxidant insights and contributes to understanding this abundant Türkiye species. A. purpurascens holds promise for pharmaceutical exploration, offering potential solutions for challenging health conditions.
AtıfScopus1OpenAlex3TR Dizin2İncele - MakaleAçık Erişim2025Scopus SJRQ1Influence of Silver Doping and Anodization Current Density on Aluminum Surface Properties and Surface Adhesion of Staphylococcus aureus and Escherichia coli
Erbakan, Mustafa; Taşdemir, Muharrem; Şenaslan, Fatih; Sarıbıyık, Oğuz Yunus
In this study, we investigated the influence of crystal structure, topography, and elemental composition of aluminum oxide surfaces on bacterial adhesion. The structural properties of the surfaces were systematically controlled by varying the current density (1.5, 2.0, and 2.5 A/dm2) and silver doping during the anodization process. The resulting changes in structural and morphological properties were examined by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), contact angle measurements, and profilometry. Using FE-SEM analysis, we evaluated the adhesion of model bacteria, Escherichia coli and Staphylococcus aureus, to surfaces exhibiting diverse morphologies and elemental compositions. The surface roughness and crystal size of the aluminum oxide increased proportionally with the applied current density and silver doping. According to the XRD results, the slip plane crystal structure of (311) increased proportionally to the current density but decreased with silver doping. Specifically, while stepped atomic alignment of (311) planes facilitates bacterial attachment, smoother (200) planes reduce the adhered bacteria population. Further analysis via XPS revealed that the oxide crystal structure of undoped surfaces shifted from the tetrahedral to octahedral form with increasing current density, while silver-doped surfaces exhibited the opposite trend. Additionally, increasing current density during the preparation of silver-doped surfaces diminished the ratio of ionic silver to metallic silver, suggesting a lowered propensity for bacterial adhesion. S. aureus adhesion to undoped surfaces increased 4.46-fold for surfaces prepared at 2.5 A/dm2 compared to that at 1.5 A/dm2. Moreover, E. coli adhesion was completely inhibited on silver-doped surfaces anodized at 1.5 A/dm2. Reducing the surface roughness and incorporating silver during the anodization of aluminum surfaces decrease the number of bacteria adhering to aluminum oxide surfaces.
- MakaleAçık Erişim2024Scopus SJRQ1Geochemical characteristic of the Lutetian black shale (Bayburt, NE-Turkey): amount, nature, origin of organic matter and palaeo-environment conditions
Eker, Çiğdem Saydam
To define the amount, thermal maturity and type of organic matter (OM), a comprehensive analysis of major and trace elements, organic carbon isotope and organic geochemistry was conducted on Lutetian black shales found in the Everek (Bayburt) region of northeastern Turkey. Total organic carbon (TOC) levels in the shale samples range from 0.62% to 6.75%, and type II–III to type III kerogen is generated, displaying a combination of high terrigenous and low marine OM. The δ13C values (ranging from –28.22 to –28.23), aromatic hydrocarbon compounds (methyl phenanthrene, dibenzothiophene, tri-aromatic and monoaromatic steroids), saturated hydrocarbon compounds (sterane and terpane), acyclic isoprenoids, n-alkane distribution (n-C13–n-C36) and inorganic geochemical characterization support that the black shales were deposited in a terrestrial-marine transition environment and had a high proportion of terrestrial OM with small amounts of marine OM preserved in relatively arid to hot climate and oxic to suboxic conditions. The analysis of biomarker thermal maturity markers, Tmax (ranging from 449–458oC) and estimated vitrinite reflectance (varying from 0.92 to 1.08%) values suggest that the black shales have reached the oil window. As a result, black shales are thought to contain low to high amounts of TOC, have a mixed kerogen type, reach a high thermal maturity level and produce little hydrocarbons.
AtıfScopus5WoS5OpenAlex3İncele - MakaleAçık Erişim2025Scopus SJRQ1Corrosion and structural properties of lightweight magnesium and aluminum alloy cores based sandwich composites
Keleş, Abdulsamet; Karabudak, Filiz; Acar, Volkan; Kula, M. Emin; Aslan, Mustafa; Karabacak, A. Hasan; Alibeyoğlu, Fatih
Metal plate core-based sandwich composites have the potential to revolutionize various industrial fields due to their mechanical strength and vibration damping. In this study, AZ91 (a magnesium alloy) and Al1050 (an aluminum alloy) metal core-based sandwich composites of AZ91/carbon fiber-epoxy, AZ91/glass fiber-epoxy, Al1050/carbon fiber-epoxy, and Al1050/glass fiber-epoxy sandwich composites were manufactured. These composites' mechanical and dynamic properties were determined through tensile, three-point bending, and vibration tests. AZ91-reinforced carbon fiber composites exhibited a 28.8% higher tensile strength than glass fiber composites, while Al1050-reinforced carbon fiber composites showed a 17.2% higher tensile strength performance than glass fiber composites. Moreover, AZ91 reinforcement led to composites with higher average flexural strength for both fibers. In vibration tests conducted under clamped and free-free boundary conditions, the highest first natural frequency was observed in AZ91/carbon fiber samples, sparking further interest. Conversely, the highest first damping ratio was observed in Al1050/glass fiber specimens. In addition, the corrosion behavior of sandwiches was evaluated, and it was found that glass fiber provided better corrosion resistance than carbon fiber. Highlights: Sandwich composites comprising AZ91/Al1050 cores and carbon/glass fiber reinforced epoxy face sheets were manufactured. Galvanic corrosion effects were evaluated, and glass fiber was found to provide higher corrosion resistance. AZ91/carbon fiber sandwich showed 28.8% higher tensile strength than glass fiber. Vibration tests revealed the AZ91/carbon fiber sandwich had the highest first natural frequency. Al1050/glass fiber sandwich exhibited the highest first damping ratio.
AtıfScopus4WoS4İncele - MakaleAçık Erişim2025Scopus SJRQ3Investigation of the impact of instagram access restriction on individuals' psychological well-being, social and cultural perceptions, and adaptation strategies
Özen, Üstün; Çam, Handan; İpkin, Metin; Kaldırımcı, Şahin Göktuğ
This study comprehensively examines the psychological impacts of the Instagram access ban implemented in Turkey between August 2, 2024, and August 10, 2024, how these impacts are reflected in social consequences and cultural perceptions, and also assesses the adaptation strategies that individuals develop in response to the ban. Data were collected from 80 participants residing in Erzurum through online surveys and analyzed using MAXQDA 24 software. The findings suggest that the access ban had various psychological effects, with some participants experiencing changes in their social relationships and difficulties in accessing information. The impacts on social bonds and solidarity varied among participants, with some cases showing intensified social interactions. In terms of cultural perceptions, changes were observed in individuals' views on freedom and expression rights. The study provides important insights into how social media access bans can influence individual perceptions and social structures, suggesting that these findings could contribute to shaping social media policies.
AtıfScopus1OpenAlex1İncele - MakaleYalnız künye2025Scopus SJRQ1First responders’ thoughts and experiences about the international search and rescue teams during the Kahramanmaras earthquakes
Kolcu, Veysel Karani; Mızrak, Sefa
National capacity may be insufficient for disasters that affect many settlements and people simultaneously. This situation requires international humanitarian assistance for post-disaster search and rescue, public health, nutrition, security, and coordination. The objective of this study was to reveal the opinions of first responders about the work of the (international search and rescue) ISAR teams following the earthquakes that occurred in Türkiye on 6 February 2023. Data were collected using a semi-structured interview form with 41 first responders who had worked with them or observed their work, and analyzed via thematic analysis using the MAXQDA 24 programme. The results were presented under seven themes: devotion, equipment and material sufficiency, knowledge and experience, coordination, cooperation, communication, and psychological resilience. The first responders stated that the ISAR teams worked wholeheartedly and that their knowledge, expertise, and equipment were sufficient and advanced. They also indicated that the teams worked in a coordinated manner and that their harmony with local teams and the public was great. However, when working with them, language-related communication barriers negatively affected the workflow. The results of this study will provide insight to organisations and managers who develop and implement international humanitarian aid policies.
