Hakkari Üniversitesi Akademik Veri Yönetim Sistemi
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Challenges of the Digital Age: The Relationship Between Internet Addiction, Loneliness and Psychological Resilience of University Students
No full textThe primary objective of this study is to investigate the correlations among problematic Internet use, social and emotional loneliness, and psychological resilience in university students. Additionally, the study aims to analyze how these associations vary based on the demographic characteristics of the students. The research participants were university students from the Hakkari district in Turkey. The research was conducted utilizing the quantitative research approach. The findings indicate a direct correlation between problematic Internet use and feelings of loneliness, as well as an inverse correlation between problematic Internet use and psychological resilience. Additionally, there is an inverse correlation between psychological resilience and loneliness. Furthermore, it was concluded that the variables of social and emotional loneliness and psychological resilience are strong predictors of problematic Internet use. Simultaneously, the findings show a significant difference between loneliness scores and the amount of time spent online. This validates the hypothesis that the utilization of the Internet can be elevated as a result of experiencing loneliness. In the future, studies conducted across different countries and samples can guide the development of educational programs that not only foster social and mental resilience but also promote responsible Internet use
Improved physical, optical, and radiation shielding characteristics of SrO-doped borate glasses: Insights from experiments and machine learning
No full textThis study investigates the influence of Strontium oxide (SrO) doping on the physical, structural, optical, and radiation shielding characteristics of borate glass systems with the composition (69-x)B₂O₃-6Na₂O-6CaO-6K₂O-6BaTiO₃-6ZnO-1Sb₂O₃-xSrO (x = 0, 1.25, 2.5 mol%, encoded AY100, AY101 and AY102). Utilizing the melt-quenching technique, glasses were synthesized and systematically characterized to evaluate their physical, optical, and nuclear radiation shielding capabilities. Experimental techniques such as XRD, FTIR spectroscopy, UV–Vis spectroscopy, and Vickers hardness tests provided insights into the influence of SrO content on glass properties. To predict glass densities, we utilized a suite of machine learning models, including Linear Regression, Bayesian Regression, Support Vector Regression, Extreme Gradient Boosting, CatBoost, and Light Gradient Boosting Machine. Among these, the XGBoost model demonstrated exceptional performance, achieving an R2 score of 0.97. Experimental measurements using Archimedes' principle confirmed that the density of the synthesized glasses increased with the addition of the SrO. The observed density increase of the 2.5 % additive glass (from 2.755 to 2.805 g/cm³) aligns with the predictions of our machine learning models. Increasing the amount of SrO doping increased the refractive index and band gap energies. Direct band gap values increased from 3.01 to 3.12 eV. The substitution of lighter B₂O₃ with heavier SrO significantly enhanced density and refractive index. The incorporation of 2.5 mol% SrO into glass led to a substantial improvement in its mechanical performance, as evidenced by a 12.5 % increase in hardness and a 13.11 % increase in yield strength. The radiation shielding performance of the glasses, another critical focus of this work, was assessed for gamma rays and fast neutrons. SrO-doped glasses demonstrated superior gamma-ray attenuation properties, with increased MAC and Zeff values, as well as reduced HVL values. The MAC values of AY100 and AY102 glasses vary between 0.597 and 0.610 cm2/g at 81 keV. Among the samples, glass with 2.5 mol% SrO exhibited the highest shielding efficiency, attributed to its enhanced density and effective atomic number. Neutron shielding effectiveness also improved, as evidenced by a higher neutron removal cross-section and absorbed dose rates. As a result of the experimental measurements, the equivalent absorbed dose rate increased from 31.36 to 34.16 % for AY100 and AY102 glasses. This comprehensive study underscores the potential of SrO-doped borate glasses as multifunctional materials for optical and radiation shielding applications
Exploring photodiode characteristics of a D-π-D type organic semiconductor incorporating a fluorenyl π-bridge and triphenylamine donors
No full textIn this study, the design, synthesis, and spectroscopic characterization of a fluorene-based electron-rich D-π-Dtype organic semiconductor material 4,4′-((9H-fluoren-9-ylidene)methylene)bis(N,N-diphenylaniline), namelyTPA2, were achieved by selecting triphenylamine (TPA) as the donor group. The Au/TPA2/p-Si/Al photodiodefabricated using TPA2 organic material as interface material. The electrical and optical properties of photodiodewere investigated. The SEM and AFM images of the TPA2/p-Si thin film were analyzed. Also, UV–Vis absorptionspectra measurement of the thin film was analyzed. The current–voltage (I-V) measurements of the diode wereperformed for different light intensity values. Electrical paremeters [ideality factor (n) and barrier height (Φb),rectification rates (RR), saturation current (I0)] and photodiode parameters [photocurrent (Iph), photosensitivity(S), photoresponse (R), detectivity (D*)] of the diode were calculated using the I-V measurements of the diode.With increasing light intensity between 0 mW/cm2 and 100 mW/cm2 light intensity, the n values varies between1.41 and 2.14, the Φb values varies between 0.81 and 0.66, the Rs values varies between 171 Ω and 1487 Ω andthe RR values varies between 196.2 and 42.4. The calculated fundamental electrical and photodiode parametersshowed that TPA2 material improved the electrical and optical parameters. The analyzed experimental resultsshow that the Au/TPA2/p-Si/Al diode exhibits a good photodiode behavior under various light intensities andthis diode can be used in optoelectronic devices.</p
Yiyecek-İçecek İşletmelerinde Mutfak Çalışanlarının İş Sağlığı ve Güvenliğine İlişkin Sorunlarının İncelenmesi: Hakkari İli Örneği
No full textStructural, elastic, electronic and optical properties of some Ruddlesden–Popper compounds
No full textThe structural, elastic, electronic and optical properties of Ruddlesden–Popper-layered (Sr,Ca)3Ti2O7 compounds in the paraelectric phase have been studied in detail using a first-principles method based on density functional theory. The results obtained from structural optimization demonstrate that they are consistent with existing experimental and theoretical results in the literature. To investigate the mechanical properties of the Sr3Ti2O7 and Ca3Ti2O7 compounds, second-order elastic constants were calculated. The obtained results confirm that the Sr3Ti2O7 and Ca3Ti2O7 compounds are mechanically stable. The polycrystalline elastic modulus, including bulk modulus (B), shear modulus (G), Young’s modulus (E) and Poisson’s ratio (ν), for both compounds was calculated using the obtained elastic constants. It was estimated from the calculated Hmacro and Hmicro hardness values that these compounds are medium-hard materials. Furthermore, both compounds were found to be elastically anisotropic and brittle materials. The electronic structure analysis indicates that the Sr3Ti2O7 and Ca3Ti2O7 compounds are semiconductor materials with indirect bandgaps of 2.92 and 2.89 eV, respectively. To determine their potential application areas in optoelectronic devices, the frequency-dependent complex dielectric function of the Sr3Ti2O7 and Ca3Ti2O7 compounds was calculated
