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  • Öğe
    Search for a scalar or pseudoscalar dilepton resonance produced in association with a massive vector boson or top quark-antiquark pair in multilepton events at ?s=13 TeV
    (American Physical Society, 2024) Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Damanakis, K.; Dragicevic, M.
    A search for beyond the standard model spin-0 bosons, phi, that decay into pairs of electrons, muons, or tau leptons is presented. The search targets the associated production of such bosons with a W or Z gauge boson, or a top quark-antiquark pair, and uses events with three or four charged leptons, including hadronically decaying tau leptons. The proton-proton collision data set used in the analysis was collected at the LHC from 2016 to 2018 at a center-of-mass energy of 13 TeV, and corresponds to an integrated luminosity of 138 fb(-1). The observations are consistent with the predictions from standard model processes. Upper limits are placed on the product of cross sections and branching fractions of such new particles over the mass range of 15 to 350 GeV with scalar, pseudoscalar, or Higgs-boson-like couplings, as well as on the product of coupling parameters and branching fractions. Several model-dependent exclusion limits are also presented. For a Higgs-boson-like phi model, limits are set on the mixing angle of the Higgs boson with the phi boson. For the associated production of a phi boson with a top quark-antiquark pair, limits are set on the coupling to top quarks. Finally, limits are set for the first time on a fermiophilic dilaton-like model with scalar couplings and a fermiophilic axion-like model with pseudoscalar couplings.
  • Öğe
    Measurement of simplified template cross sections of the Higgs boson produced in association with W or Z bosons in the H ? bb decay channel in proton-proton collisions at ?s=13 TeV
    (American Physical Society, 2024) Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Damanakis, K.; Dragicevic, M.
    Differential cross sections are measured for the standard model Higgs boson produced in association with vector bosons (Formula Presented, Formula Presented) and decaying to a pair of Formula Presented quarks. Measurements are performed within the framework of the simplified template cross sections. The analysis relies on the leptonic decays of the Formula Presented and Formula Presented bosons, resulting in final states with 0, 1, or 2 electrons or muons. The Higgs boson candidates are either reconstructed from pairs of resolved Formula Presented-tagged jets, or from single large-radius jets containing the particles arising from two Formula Presented quarks. Proton-proton collision data at Formula Presented, collected by the CMS experiment in 2016-2018 and corresponding to a total integrated luminosity of Formula Presented, are analyzed. The inclusive signal strength, defined as the product of the observed production cross section and branching fraction relative to the standard model expectation, combining all analysis categories, is found to be Formula Presented. This corresponds to an observed (expected) significance of 6.3 (5.6) standard deviations.
  • Öğe
    Investigation of the electromagnetic shielding efficiency of FeB and Fe2B: ab-initio calculations
    (Institute of Physics, 2024) Üşenti, Hakan; Duru, İzzet Paruğ
    The electromagnetic (EM) pollution that we are exposed to in our daily lives has reached levels that threaten the health of living organisms and the stable operation of sensitive systems. The most effective way to protect against this pollution is to create isolated areas framed with shielding materials that can minimize the transmission of EM radiation. The development of shielding materials with high physical endurance against external factors to meet the needs of various sectors remains a popular research topic. This process, which started with metal plates, has continued with the development of doped polymers and composite materials. In recent years, materials with 2D structures have been developed. In this study, the shielding effectiveness (SE) of FeB and Fe2B nanostructures are revealed using ab initio calculations in Perdew-Burke-ErnzerhofSol scheme. SE has been widely figuring out via optical properties which are strongly related to mechanical and electronic properties herewith magnetic phases. The ferrimagnetic FeB and Fe2B nanostructures are considered. Besides, we focus on the thickness and photon energy dependent behavior along various projections. The findings demonstrate shielding performance at levels of >20 dB. Although both materials show similar shielding performance, it is observed that Fe2B is promising when compared to FeB. This study demonstrates that FeB and Fe2B, members of the MBene family, are promising materials not only because of their superior physical and chemical properties but also because of their shielding performance.
  • Öğe
    Correlation of proton conductivity and free volume in sulfonated polyether ether ketone electrolytes: a positron annihilation lifetime spectroscopy study
    (Elsevier Ltd, 2025) Lahmuni, Muhammet; Yılmazoğlu, Mesut; Abacı, Ufuk; Çoban, Ozan; Yumak Yahşi, Ayse; Tav, Cumali; Yahşi, Uğur
    Proton-conducting polymers play a pivotal role in clean energy technologies and various industrial applications, with a significant emphasis on enhancing energy efficiency and minimizing environmental impact. Sulfonated polyether ether ketone (SPEEK), which is renowned for its proton conductivity, has emerged as a key material in electrochemical processes, notably in proton exchange membrane (PEM) fuel cells. This study investigated the proton conductivity and dielectric behavior of SPEEK electrolytes at varying degree of sulfonation (DS) of 65% and 80%, correlating these properties with free volume profiles determined by positron annihilation lifetime spectroscopy (PALS). The SPEEK-65 and SPEEK-80 electrolytes were prepared via a controlled sulfonation process and characterized by FTIR, TGA, and SEM analyses. Proton conductivity and dielectric measurements were conducted at temperatures ranging from 300 to 370 K and frequencies ranging from 20 Hz to 1 MHz. The results revealed that SPEEK-80 exhibited a maximum proton conductivity of 3.4 × 10?2 S/m at 300 K and 1 MHz, which was significantly greater than the 4.38 × 10?3 S/m observed for SPEEK-65 under the same conditions. PALS analysis demonstrated a notable increase in free volume with increasing DS, with SPEEK-80 showing a higher o-Ps lifetime and intensity, indicating larger free volume sizes and fractions. These findings underscore the critical interplay between DS, free volume, and proton conductivity, offering insights into optimizing SPEEK-based electrolytes for advanced electrochemical applications.
  • Öğe
    Observation of the ?(3S) meson and suppression of ? states in Pb-Pb collisions at ?sNN=5.02 TeV
    (American Physical Society, 2024) Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, Thomas; Chatterjee, S.; Damanakis, Konstantinos; Dragicevic, M.
    The production of Upsilon(2S) and Upsilon(3S) mesons in lead-lead (Pb-Pb) and proton-proton (pp) collisions is studied in their dimuon decay channel using the CMS detector at the LHC. The Upsilon(3S) meson is observed for the first time in Pb-Pb collisions, with a significance above 5 standard deviations. The ratios of yields measured in Pb-Pb and pp collisions are reported for both the Upsilon(2S) and Upsilon(3S) mesons, as functions of transverse momentum and Pb-Pb collision centrality. These ratios, when appropriately scaled, are significantly less than unity, indicating a suppression of Upsilon yields in Pb-Pb collisions. This suppression increases from peripheral to central Pb-Pb collisions. Furthermore, the suppression is stronger for Upsilon(3S) mesons compared to Upsilon(2S) mesons, extending the pattern of sequential suppression of quarkonium states in nuclear collisions previously seen for the J/psi, psi(2S), Upsilon(1S), and Upsilon(2S) mesons.
  • Öğe
    Synthesis and characterization of metakaolin-based geopolymers doped with CRT waste glass for radiation shielding applications
    (Elsevier, 2024) Al-Buriahi, M. S.; Kırkbınar, Mine; Alrowaili, Ziyad Awadh; Katubi, Khadijah Mohammedsaleh; Alsaiari, Norah Salem; Alalawi, Amani; Alomayrah, Nora; Olarinoye, I. O.
    This study presents the influence of CRT glass on the gamma-ray interaction processes in metakaolin-based geopolymers. Four batches of G-CRT composites (namely, G, G-10CRT, G-20CRT, and G-30CRT, which represent geopolymer (G) samples doped with 0, 10, 20, and 30 wt% of CRT glass) were prepared using the cold hydrostatic press method. The mass attenuation coefficients of the prepared C-xCRT samples were computed using XCOM and FLUKA simulations for photons within the energy range of 15 keV-15 MeV. The density of the pristine geopolymer increased from about 1.86 g/cm3 3 to 2.09, 2.26, and 2.34 g/cm3 3 for G-10CRT, G-20CRT, and G-30CRT, respectively. The photon mass and linear attenuation coefficients of the geopolymers increased with CRT glass concentration. The half-value layer and mean free path were within the ranges 0.070-18.079 cm and 0.101-26.083 cm for G; 0.036-15.110 cm and 0.052-21.799 cm for G-10CRT; 0.024-13.197 cm and 0.014-19.039 cm for G-20CRT; and 0.018-12.074 and 0.026-17.419 cm for G-30CRT. The G-30CRT had the best gamma attenuating prowess in contrast to other G-xCRT. CRT-rich G-xCRT had a higher effective atomic number. For 10 mm thick geopolymer, the absorbed dose rates were 0.211 mu R/h, 0.66 mu R/h, 1.11 mu R/h, and 1.55 mu R/h for G, G-10CRT, G-20CRT, and G-30CRT, respectively, for 100 keV photons. The introduction of CRT glass into the geopolymer matrix improved their photon interaction cross-section. The geopolymers showed outstanding photon interaction ability compared to ordinary concrete and some shielding glasses at low photon energies. The CRT glass-doped geopolymer samples are useful for preparing radiation shielding concrete.
  • Öğe
    Relationship between external debt and economic growth: an econometric analysis of the Turkish economy
    (Istanbul University, 2024) Yavuz, Yağmur; Polat, Mehmetsıddık
    The phenomenon of economic growth being a leading indicator of economic progress in developing countries has long been accepted by economists and policymakers. In contrast to advanced economies, in developing economies, the pursuit of growth based on limited savings and capital accumulation often requires overcoming challenges through the utilisation of external resources, leading countries in this group, including Turkey, to resort to foreign borrowing. The contribution of external debt to economic growth after acquisition varies depending on the countries' existing domestic resources and the areas in which the borrowed funds are utilised. Similarly, population growth and openness to foreign trade are key economic sources for many developing countries with limited productive resources. In this study, the external debt-economic growth relationship is discussed using economic variables based on the 1973-2021 period for the Turkish economy. Traditional unit root tests, namely the Augmented Dickey-Fuller Unit Root Test and the Phillips-Perron Unit Root Test, are employed in the analysis. This study also investigates the stationarity of variables using the Narayan and Popp (2010) Unit Root Test, which considers structural breaks, and the non-linear Fourier Kruse Unit Root Test developed by G & uuml;rig(2019), where structural breaks are modelled using Fourier functions. Furthermore, the long-term relationships between variables is examined using the ARDL Bound Test. The results indicate that external debt and population growth rate have a statistically significant and negative impact on economic growth, whereas the effect of openness to foreign trade on economic growth is statistically significant and positive.
  • Öğe
    Respiratory responses and isocapnic buffering phase in child and youth soccer players during an incremental exercise test
    (Frontiers Media SA, 2024) Korkmaz Eryılmaz, Selcen; Karakaş, Selçuk; Boyraz, Cumhur; Günaştı, Özgür; Kılcı, Abdullah; Özdemir, Çiğdem; Özgünen, Kerem; Koç, Muhammed; Adaş, Ümit; Kurdak, Sadi
    Purpose: This study investigated the respiratory response and isocapnic buffering (IB) phase during an incremental exercise test to exhaustion in 16 child soccer players (11.9±0.9 years) and 18 youth soccer players (18.2±2.9 years). Methods: The IB phase was calculated as the difference in oxygen uptake (VO2) between the respiratory compensation point (RCP) and metabolic threshold (MT) and expressed in either absolute or relative values. Results: The maximal oxygen uptake (VO2max) was higher in youth players than in child players. For youth players, VO2max was measured at 55.9 ± 3.6 mL min?1 kg?1 and 74.9 ± 4.8 mL min?1 kg?0.75, while for child players, VO2max was 50.8 ± 4.1 mL min?1 kg?1 and 67.2 ± 6.1 mL min?1 kg?0.75 (p < 0.001). MT and RCP occurred at 69.8 ± 6.7% and 90.9 ± 6.9% of VO2max in child players and at 73.9 ± 5.1% and 91.5 ± 4.5% of VO2max in youth players, respectively. The two groups had no significant difference (p > 0.05). Absolute IB (10.6 ± 2.8 vs 9.7 ± 3.1 mL min?1 kg?1), relative IB (23.1 ± 5.7 vs 19.1 ± 6.1), and the ratio of RCP VO2 to MT VO2 (1.3 ± 0.09 vs 1.24 ± 0.09) were similar in child and youth players (p > 0.05). There was no difference in minute ventilation (V?E, mL min?1 kg?1) and respiratory exchange ratio during exercise between the two groups (p > 0.05). During exercise, respiratory frequency, ventilatory equivalent for carbon dioxide (VE/VCO2) and oxygen (VE/VO2), VE/VCO2 slope, end-tidal O2 pressure were higher in child players than in youth players, while tidal volume (L kg?1), O2 pulse, and end-tidal CO2 pressure were lower (p < 0.05). Conclusion: Despite differences in aerobic capacity and ventilatory response to exercise, child players showed similar IB phase as youth players. Although child players have lower ventilation efficiency than youth players, the higher ventilation response for a given VCO2 may provide an advantage in regulating acid-base balance during intense exercise.
  • Öğe
    The boundary value problem for an ordinary linear half-order differential equation
    (E.A. Buketov Karaganda University Publish House, 2024) Aliyev, Nihan; Rasulov, Mahir; Sinsoysal, Bahaddin
    This study is devoted to the study of the solution of a boundary value problem for an ordinary linear differential equation of half order with constant coefficients. Using of the fundamental solution of the main part of the considered equation, we obtained the principal relations, from which we obtain the necessary conditions for the Fredholm property of the original problem. Further, using the Mittag-Leffler function, a general solution of the homogeneous equation is obtained. Finally, the problem under consideration is reduced to an integral Fredholm equation of the second kind with a non-singular kernel, i.e., the Fredholm property of the stated problem is proved.
  • Öğe
    (?i, ?)-constacyclic codes and DNA codes over Z4
    (AIMS Mathematics, 2024) Uzekmek, Fatma Zehra; Öztaş, Elif Segah; Özen, Mehmet
    In this paper, three new automorphisms were identified over the ring Z(4)+uZ(4)+u(2)Z(4) where u(3 )= u(2). With the help of these automorphisms, the characteristic structures of the generator polynomials for the theta i-cyclic codes and (theta(i),lambda)-constacyclic codes of odd length on this ring were investigated. Also, for all the units over the ring, Z(4)-images of theta i-cyclic and (theta(i),lambda)-constacyclic codes were reviewed with the associated codes based on determined transformations. Using these observations, new and optimal codes were obtained and presented in the table. In addition, a new transformation was identified that involved DNA base pairs with the elements of Z(4). Moreover, a unit reverse polynomial was created, and in this way a new generation method has been built to construct reversible DNA codes over this ring. Finally, this article was further enhanced with supporting examples of the DNA as a part of the study.
  • Öğe
    Investigating ultra-thin rGO coated ZnO core-shell structures in MOS devices: electrical/dielectric characteristics and relaxation mechanism
    (Elsevier Ltd, 2024) Kırkbınar, Mine; İbrahimoğlu, Erhan; Demir, Ahmet; Çalışkan, Fatih
    The study focused on the relaxation and polarisation mechanisms of Al/(rGO:ZnO core-shell)/pSi/Al MOS structures. For this purpose, the rGO:ZnO core-shell structures were synthesised by sol-gel procedures and coated on pSi by spin-coating. The structures were characterized as chemical, morphological and micro-structural using FESEM-EDS, AFM, XRD and Raman analysis. Additionally, the capacitance (C), conductance (G/omega), dielectric permittivity (epsilon ' and epsilon ''), loss factor(tan delta), electric modulus(M ' and M '') of the samples were successfully examined by DS over the wide range of frequencies (100 Hz-1 MHz) for determining dielectric parameters. Three distinct regions were visible on the C-V and C-omega plots: accumulation (-4 to 0 V), depletion (0 to 2 V), and inversion (2 to 4 V). Two relaxation times (10(-4)s-10(-7)s) were obtained in epsilon '-V and epsilon '-omega graphs between 1-100 kHz (region 1) and 100 kHz-1 MHz (region 2). The relaxation times were according to the Maxwell-Wagner and dipolar polarisation mechanism. As a result, the capacitive effect was observed and the equivalent RC circuit obtained from the Cole-Cole diagrams allowed the samples to be used in energy storage or different electronic applications.
  • Öğe
    Co2 emisyonlarını etkileyen faktörlerin zamanla değişen katsayılı parametrik olmayan panel veri modelleri ile analizi
    (İstanbul Üniversitesi, 2023) Güriş, Selahattin; Çağlayan, Sevcan
    İklim değişikliğinin, küresel ısınmanın ve çevresel bozulmanın bir nedeni olarak karbondioksit (CO2) emisyonlarından oluşan sera gazları gösterilmektedir. CO2 yeryüzüne insan faaliyetleri nedeniyle yayılarak genellikle çevreye zarar verir ve iklim değişikliğine veya küresel ısınmaya yol açar. Bu sebeple CO2 emisyonlarını etkileyen ekonomik ve ekonomik olmayan birçok sosyal faktör araştırmalara konu olmuştur. Ancak çoğu araştırmada CO2 emisyonları konusunda hem ekonomik büyüme hem de enerji kullanımı gibi ana faktörleri de etkileyen ekonomik belirsizlik dikkate alınmamıştır. Bu çalışmada kişi başına düşen CO2 emisyonları ve başta ekonomik belirsizlik (dünya belirsizlik indeksi ile ölçülen) olmak üzere diğer değişkenler arasındaki ilişki ele alınmıştır. 14 OECD ülkesinin 2000-2021 yılları arasındaki verileri zamanla değişen katsayılı parametrik olmayan panel veri modeliyle incelenmiştir. Trend fonksiyonları ve parametrik olmayan katsayı fonksiyonları tahmin edilerek doğrusal olmayan sonuçlara ulaşılmıştır. Parametrik olmayan katsayı fonksiyonlarının CO2 emisyonları üzerinde etkisi zaman içerisinde değişiklik göstermektedir. Sonuçlarımıza göre ele alınan dönem boyunca ekonomik belirsizlik ile CO2 emisyonları arasında ters yönlü bir ilişki bulunmaktadır ve zaman içerisinde düşüş eğiliminde devam etmektedir. Kişi başına düşen GSYH, nüfus ve yenilenebilir enerjinin parametrik olmayan katsayıları zaman içerisinde negatif ve pozitif olarak değişmektedir. Ticaret 2000’li yıllarında başında anlamsız bir değişken olmasına rağmen 2009-2013 yılları arasında anlamlı bir değişkendir, ancak 2021 yılında etkisi tekrar anlamsızlaşmıştır.
  • Öğe
    Microstructural and mechanical characterizations of weld metal of S960QL ultra high strength steel joints obtained with different multi-pass laying techniques using GMAW
    (Institute of Physics, 2024) Mert, Tolga; Gürol, Uğur; Tümer, Mustafa
    15 mm thick ultra-high strength steel plates with 960 MPa yield strength were welded using different multi-pass laying techniques (i.e., stringer and weaving beads) with torch manipulation. Weld metals obtained were compared using different mechanical (i.e., micro tensile tests and Vickers hardness maps) and microstructural (i.e., optical microscope, scanning electron microscope, x-ray diffraction, electron backscatter diffraction) characterization techniques. Coarser grains and acicular ferrite were observed in weld metal obtained with the weaving pass procedure. There were hardness differences in the face and root passes of both weld metals. Yet, hardness values were 19% and 11% higher for the face and root regions of the joint obtained by stringer pass procedure, respectively. Fractographs of micro tensile test specimens revealed dimples depicting ductile network structure for both joints.
  • Öğe
    The impact of different telerehabilitation methods on peripheral muscle strength and aerobic capacity in COPD patients: a randomized controlled trial
    (Multidisciplinary Digital Publishing Institute (MDPI), 2024) Ataç, Amine; Pehlivan, Esra; Karaahmetoğlu, Fulya Senem; Özcan, Zeynep Betül; Çınarka, Halit; Çörtük, Mustafa; Baydili, Kürşad Nuri; Çetinkaya, Erdoğan
    Lung diseases have profound effects on the aging population. We aimed to hypothesize and investigate the effect of remote pulmonary telerehabilitation and motor imagery (MI) and action observation (AO) methods on the clinical status of elderly chronic obstructive pulmonary disease (COPD) patients. Twenty-six patients were randomly assigned to pulmonary telerehabilitation (PtR) or cognitive telerehabilitation (CtR) groups. The programs were carried out 3 days a week for 8 weeks. The 6-min walk test (6MWT), modified Medical Research Council dyspnea score, blood lactate level (BLL), measurement of peripheral muscle strength (PMS), and electromyography activation levels of accessory respiratory muscles were the main outcomes. There was a statistically significant improvement (p < 0.05) in both groups in the 6MWT distance and in secondary results, except for BLL. Generally, in the mean muscle activity obtained from the electromyography measurement after the program, there were statistically significant increases in the PtR group and decreases in the CtR group (p < 0.05). There was a statistically significant increase in PMS in both groups. An active muscle-strengthening program has the same benefits as applying the muscle-strengthening program to the patient as MI and AO. CtR can be a powerful alternative rehabilitation method in respiratory patients who cannot tolerate active exercise programs.
  • Öğe
    Proton conductivity and dielectric studies on chitosan/polyvinyl alcohol blend electrolytes: synergistic improvements with ionic liquid and graphene oxide
    (Elsevier B.V., 2024) Yılmazoğlu, Mesut; Okkay, Hikmet; Abacı, Ufuk; Çoban, Ozan
    This study investigates the impact of ionic liquid, 1-methylimidazolium tetrafluoroborate (IL) and graphene oxide (GO) on the performance of chitosan/polyvinyl alcohol (CS/PVA)-based composite electrolytes. Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) confirm the successful incorporation of IL and GO, affecting the structural and morphological properties of the electrolytes. Thermogravimetric analysis (TGA) reveals enhanced thermal stability in GO-doped samples, with increased residual weight at high temperatures, while IL addition leads to higher initial weight loss due to its hygroscopic nature. Ionic conductivity measurements demonstrate that the CS/PVA/IL-GO(4.0) composite achieves the highest proton conductivity of 1.76 × 10?3 S/m at 300 K and 1 MHz, surpassing other samples and aligning with top values reported in literature. Dielectric studies show a significant increase in dielectric constant to 9.55 × 104 at 300 K and 20 Hz for CS/PVA/IL-GO(4.0), attributed to enhanced dipole alignment and polarization effects. The loss tangent analysis indicates the shortest relaxation time of 2.07 × 10?4 s for CS/PVA/IL-GO(4.0), correlating with its superior proton conductivity. These findings highlight the potential of CS/PVA/IL-GO electrolytes for advanced energy storage and conversion applications, suggesting further research into GO dispersion and long-term stability for optimized performance in practical devices.
  • Öğe
    Normative values and calculation formulas of respiratory muscle strength of adults in Turkish society: A population-based study
    (AVES, 2024) Pehlivan, Esra; Çınarka, Halit; Baydili, Kürşad Nuri; Uyaroğlu, Mehmet Burak; Baştürk, Pınar; Ataç, Amine
    OBJECTIVE: This study aimed to establish normative values for maximum inspiratory pressure and maximal expiratory pressure in the Turkish population while creating specific equations to calculate these values. MATERIAL AND METHODS: The study involved 219 healthy adults, with a minimum of 50 individuals in specific age ranges: 20–29, 30–39, 40–49, and 50–60 years. Each age group comprised at least 25 males and 25 females. Participants were required to be free from health conditions influencing respiratory muscle strength and non-smokers. Measurements of maximum inspiratory pressure and maximal expiratory pressure were recorded for all participants. RESULTS: As a result of the regression analysis performed for the maximum inspiratory pressure values, the model P value was <.001, and the R2 value was found to be 0.261. The equation obtained as a result of the model was: 82.583 ? 3.218 × gender ? 0.093 × age + 9.534 × height + 0.343 × weight. As a result of the regression analysis performed for maximal expiratory pressure values, the model P value was <.001, and the R2 value was found to be 0.285. The equation obtained as a result of the model was: 157.165 ? 35.522 × gender ? 0.271 × age–42.036 × height + 0.787 × weight. CONCLUSIONS: The newly developed equations offer valuable tools for evaluating respiratory muscle strength in the Turkish population. These results confirm the importance of using maximum inspiratory pressure and maximal expiratory pressure to monitor changes in each patient, while also emphasizing the necessity of reliable reference equations.
  • Öğe
    Navigating humanitarian aid in syria: challenges, complexities, and paths to sustainable solutions
    (SETA Foundation, 2024) Baroud, Saeed; Karsavuran, Orhun Cem; Atar, Emrah
    This study explores the role of foreign aid as a soft power tool by providing an understanding of the interrelation between foreign policy and aid. The study is based on interviews with aid experts. The findings of the study unambiguously demonstrate that aid and foreign policy are intertwined since, in most cases, foreign aid falls under the responsibility of foreign ministries. Besides the humanitarian imperative, the geopolitical account has a crucial importance in the decision-making process that cascades down from the general foreign policy agenda. In addition, the strategic interests of the donor country are contributing to the decision-making. The prominent themes are national security, tackling terrorism, preventing immigration influx, and economic goals. The study also demonstrates the extent to which aid can be politicized in its extreme form by focusing on Russian vetoes in the UN Security Council and the Syrian government’s weaponization of aid.
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    DDoS detection in electric vehicle charging stations: A deep learning perspective via CICEV2023 dataset
    (Elsevier B.V., 2024) Anlı, Yağız Alp; Çıplak, Zeki; Sakalıuzun, Murat; İzgü, Şeniz Zekiye; Yıldız, Kazım
    Distributed Denial of Service (DDoS) attacks have always been an important research topic in the field of information security. Regarding specialized infrastructures such as electric vehicle charging stations, detecting and preventing such attacks becomes even more critical. In the existing literature, most studies on DDoS attack detection focus on traditional methods that analyze network metrics such as network traffic, packet rates, and number of connections. These approaches attempt to detect attacks by identifying anomalies and irregularities in the network, but can have high error rates and fail to identify advanced attacks. Conversely though, detection methods based on system metrics use deeper and more insightful parameters such as processor utilization, memory usage, disk I/O operations, and system behavior. Such metrics provide a more detailed perspective than network-based approaches, allowing for more accurate detection of attacks. However, work in this area is not yet widespread enough further research and improvement are needed. The adoption of advanced system metrics-based methods can significantly improve the effectiveness of DDoS defense strategies, especially in next-generation and specialized infrastructures. This paper evaluates the applicability and effectiveness of Long ShortTerm Memory (LSTM) and Feed-Forward Network (FFN) in detecting DDoS attacks against electric vehicle charging stations through system metrics using CICEV2023 dataset. Experimental results show that the LSTM based model offers advantages in terms of speed and processing capacity, while the FFN is superior in terms of the accuracy.
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    Investigation of the network made with the complementary motor of the thalamus with the DTI method in individuals with tinnitus
    (Kare Publishing, 2024) Elpen Karyemez, Pınar; Yağımlı, Mustafa; Tozan, Hakan
    Objectives:This This study aimed to investigate the differences in the networks between the thalamus and the supplementary motor area in brain MRI examinations of individuals with subjective chronic tinnitus and healthy control groups. Methods: In the study, brain MRI imaging was performed on 47 patients suffering from bilateral tinnitus for two years or more and 42 healthy individuals. The tensor information obtained using the diffusion tensor imaging sequence data obtained from both groups was processed in the DSI Studio program. Brain connection maps were obtained from the data obtained. Quantitative information of the individual connecogram maps of each case was recorded and the groups were compared. Results: In the tinnitus group, there is an increase in the pathways between the thalamus and the supplementary motor area. In addition, it was determined that the pathways of the thalamus with the hippocampus, superior and middle occipital area and frontal area increased, and the pathways with the hippocampus and cerebellum decreased. Conclusion: Important functions of the supplementary motor area and thalamus; These are cognitive actions in which attention plays an important role, such as noticing the stimulus from the environment, planning and implementing the response action. It is thought that changes in the pathways between the thalamus and the supplementary motor area will especially affect attention-related functions.
  • Öğe
    Analysis and evaluation of quality parameters of commercial propolis products using a new high Performance Liquid Chromatography (HPLC) method and Comparison of antimicrobial properties
    (Elsevier Inc., 2024) Karagül, Bora; Uğraş, Serpil; Karagül, Pınar; Usta, Mehtap; Uğraş, Halil İbrahim
    Propolis, which has an important place in functional foods, is a natural bee product with high biological active value and is consumed in different formulations and packages worldwide. Thanks to the active compounds it contains, propolis shows biological properties such as antibacterial, antifungal, antiviral, antiprotozoal, antitumoral, antiulcer and anti-inflammatory. However, it is seen that propolis supplements are prepared unconsciously in the market. Such commercial products need to be standardized. Within the scope of this study, characteristic compounds of Turkish propolis were initially determined with support from the literature. Subsequently, bioactive components of 23 commercial propolis products were analyzed using the new HPLC method. Then, the flavonoid content and antimicrobial activity of the samples were determined. According to the results of these analyses, the amounts of Caffeic Acid (2,16-1620,57 ppm, Quercetin (0,19-203,99 ppm), Apigenin (0,30-319,08 ppm), Kaempferol (0,56-251,15 ppm), Chrysin (3,97-2830,93 ppm), and Caffeic Acid Phenethyl Ester (13,08-9666,48 ppm) were found to be quite different. The highest flavonoid content was measured as P2: 20847,43 mg/L and the lowest was 00003,10 mg/L in sample P13. Samples prepared for children were found to be highly diluted in terms of content. Again, it was determined that the samples with high preservation of active ingredients were products with production certificates based on laboratory analyzes. The samples were generally found to have inhibition activity against Gram (+) bacteria. Propolis samples P6 and P22 showed high activity against Gram (+) and Gram (-) bacteria and even fungi. When we evaluated some products that are insufficient in terms of content and antimicrobial activity, it was observed that antimicrobial activity increased depending on the other auxiliary chemicals used in the products. In this context, propolis products, which are very valuable in terms of health, may lose their real activity due to uncontrolled production and will gradually be devalued in the market. It is important that this valuable product should be produced and offered to the market with the necessary analysis methods without losing its effectiveness.