Van Yüzüncü Yıl University Research Information System
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ENHANCED IMPULSIVE STABILIZATION RESULTS OF DIFFERENTIAL AND INTEGRO-DIFFERENTIAL EQUATIONS OF SECOND ORDER
No full textThis paper delves into the exponential stabilization of delay differential equations (DDEs) and integro-delay differential equations (IDDEs) of second order including multiple constant retardations. By means of impulsive controls (ICs), we prove that the considered DDEs and IDDEs of second order can be exponentially stabilized. By defining two new Lyapunov-Krasovskiı̆ functionals (LKFs), we prove four new results on the exponential impulsive stabilization of the equations. Two examples are given to show numerical applications of the results. The results of this paper generalize and enhance some recent and related results in the literature
On the generalized fractal calculus of variations
No full textIn this paper, we provide a brief overview of fractal calculus and present a comprehensive study of the calculus of variations for functionals on fractal sets. We begin by introducing the calculus of variations for functionals with several dependent variables on fractal sets. We then explore the calculus of variations for functionals with several independent variables on fractal sets. Subsequently, we investigate the calculus of variations for functionals with both several independent and dependent variables on fractal sets. Finally, we suggest applications of fractal calculus of variations in physics, providing examples and plots to illustrate the details
Fractal green function theory
No full textThis paper provides a comprehensive study of fractal calculus and its application to differential equations within fractal spaces. It begins with a review of fractal calculus, covering fundamental definitions and measures related to fractal sets. The necessary preliminaries for understanding fractal Green’s functions are introduced, laying the groundwork for further exploration. We develop the fractal Green’s function for inhomogeneous fractal differential equations and extend this to the fractal Helmholtz equation. The application of the fractal Green’s function to the Schrödinger equation is also investigated, focusing on the fractal Schrödinger-type differential equation with a fractal mesonic potential. Additionally, the scattering amplitude is derived within the fractal Born approximation, offering insights into scattering phenomena in fractal spaces. The findings highlight the significant impact of fractal geometry on classical and quantum mechanics and present new methods for addressing problems in fractal environments
Post-disaster permanent housing and life satisfaction in Van, Turkey: Impacts of housing satisfaction, socioeconomic and demographic factors
No full textThis study investigates the factors influencing life satisfaction among residents of post-disaster permanent housing in Van, Turkey, following the 2011 earthquake. Data were collected through a survey of 382 households across five districts, examining socioeconomic factors, housing satisfaction, and their impact on overall life satisfaction. Multiple regression analysis revealed that income, satisfactions from housing attributes, neighborhood characteristics and social activities, and demographic factors significantly influence residents' life satisfaction. Households facing fewer difficulties meeting housing expenditures reported higher levels of life satisfaction. The study highlights that both objective housing attributes, such as housing quality, and subjective perceptions, such as neighborhood satisfaction and sense of community, significantly influence residents' overall life satisfaction. These findings, consistent with existing research, underscore the importance of addressing socioeconomic disparities and improving housing quality to enhance residents' well-being. The study emphasizes the need to incorporate residents' needs and preferences into post-disaster permanent housing policies to promote successful resettlement and ensure the long-term well-being of disaster-affected communities
Determination of the Elemental Impurity Levels in Different Mushroom Species and Probabilistic Risk Assessment
No full textMushroom cultivation and traditional mushroom procurement are widespread worldwide. Therefore, it is important to determine the extent of the risk of heavy metal exposure by consuming wild edible mushrooms. The aim of this study was to determine the levels of four elemental impurities (Cd, Pb, As, and Hg) in edible mushroom species (Macrolepiota mastoidea, Bovista aestivalis, Tricholoma fracticum, Helvella sp., and Rhizopogon roseolus) collected from Çanakkale and Van regions of Türkiye and to investigate potential health risks. For elemental impurity analysis, 0.3 g dry samples of mushrooms collected in Çanakkale and Van provinces between 2022 and 2023 were weighed and analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). Target hazard quotient (THQ) was calculated for non-carcinogenic risk assessment in children and adults, followed by hazard index (HI) for each mushroom. Carcinogenic risk (CR) was determined. Probabilistic total THQ and total CR in children and adults were calculated using the Monte Carlo simulation method. Cd levels in five mushroom species ranged between 11.19–4838.71 μg/kg, Pb levels between 495.43 and 2836.81 μg/kg, As levels between 3267.52 and 25823.07 μg/kg, and Hg levels between 0.00 and 1594.50 μg/kg. The non-carcinogenic risk potential of As level was observed in all mushroom samples. THQ value was found to be greater than 1. These values also affected the HI value in all mushrooms; the latter was also greater than 1. Since As was detected in all mushrooms in the study and the CR value of this risk element was at a level that may pose a potential carcinogenic hazard, a potential health risk in adults and children can be noted. Furthermore, the Monte Carlo simulation showed that the health risks due to elemental impurity accumulation in mushrooms may increase significantly in children and adults, causing serious health problems. Children are more severely affected by elemental impurity concentrations than adults, especially considering their body weight, which makes it necessary to take protective measures
Tomography of the source zone of the February 6, 2023, Kahramanmaraş Earthquake Doublets of Southern Anatolia
No full textOn February 6, 2023, two destructive earthquakes and many posterior aftershocks hit the Kahramanmaraş area in the south Anatolia region. The Kahramanmaraş earthquake sequence (KMES) caused extensive damage and economic losses in Türkiye and Syria. In this study, the 3-D crustal seismic velocities surrounding the hypocentral region of the KMES are determined using a large dataset of body wave arrival times obtained from local earthquakes. To better constrain the physical properties and seismogenic behavior of the KMES source region, the Vp/Vs ratio was calculated and correlated with Poisson's ratio using the obtained velocity models. To gain a better understanding of the stress conditions and regional earthquake activity in the study area, the depth variation of the b-value was also examined. Velocity structure is generally heterogeneous with both low and high velocities at upper crustal depths. Along the East Anatolian Fault Zone and its environs, low-velocity anomalies are charted. Also, small b-values (<1.0) are estimated in the region encompassing the KMES, especially at the upper crustal depths. The KMES source zone is characterized by low b-value, low to average Vp, low Vs, and average/high Vp/Vs. Hit count rates and the resolution test show that the mapped velocity anomalies are robust down to a depth of 45 km in the uppermost mantle of the affected area. Therefore, the moderate/high Vp/Vs and small b-values at the upper and middle crustal depths along the EAFZ can reflect the next earthquake hazards of the study region. The present findings give deeper insight into the physical properties and the seismogenic potential of the crustal zones in proximity to the active fault segments of the Anatolian plateau and the northwestern part of Arabia.</p
Great Deluge-based metaheuristic incorporating integer nonlinear programming for modeling and solving dynamic capability-based machine layout problem
No full textThis paper introduces a novel Dynamic Capability-Based Machine Layout (DCB-ML) problem by integrating the Quadratic Assignment Problem (QAP) formulation with a Dynamic Capability-Based Part Flow Assignment (DCB-PFA) problem. This integration enables the simultaneous consideration of machines’ processing capabilities, routing flexibility, dynamic flow assignment, and machine capacity utilization. First, a new Integer Nonlinear Programming (INLP) model is developed. The dynamic part flows are determined via the DCB-PFA sub-problem, while machine–location assignments are obtained by solving QAP. To address the complex nature of this problem, a hybrid solution approach is proposed that combines a Great Deluge Algorithm (GDA) with a Mixed-Integer Linear Programming (MILP) model, complemented by local search procedures. Since the problem has a decomposable structure, the proposed approach allows each sub-problem to be addressed independently, while the overall solution quality is jointly evaluated. Decomposition reduces the size of the resulting MILP model, as several binary variables and assignment constraints are eliminated. The proposed hybrid approach is also compared with the INLP and its linearized equivalent on several test problems. For large-scale problems with medium to high capability overlaps, nonlinear and MIP solvers fail to obtain feasible solutions, whereas the proposed approach can efficiently generate high-quality solutions within reasonable times. Moreover, when the effects of different machine-capability overlaps are investigated, it is observed that the solution of the problem will be more complex in the case of higher machine-capability overlaps. However, considering machine capabilities improves overall layout scores and eliminates the necessity of frequent reconfigurations, which is costly and time-consuming
Âhiret Gününde Amellere Şahitlik Edecek Unsurlar: Kur’ân ve Sünnet Merkezli Bir İnceleme
No full textEfficacy of Bakuchiol in a Rat Model of Chemical Eye Injury
No full textPurpose: To evaluate the therapeutic effects of bakuchiol on clinical and histopathological outcomes in a rat model of corneal alkali burn. Methods: Corneal alkali burns were induced in the right eyes of 35 male Wistar rats, which were randomized into five groups: control, carbomer, steroid, 0.14 mg/g bakuchiol, and 0.28 mg/g bakuchiol. Examinations were performed under stereomicroscopy with intraperitoneal ketamine anesthesia on days 0, 3, 7, and 14 to assess corneal epithelial defects and opacity; on day 14, corneal neovascularization was additionally evaluated. After the final examination, the eyes were enucleated, and the corneas were processed for hematoxylin–eosin and immunohistochemical staining. Epithelial necrosis, inflammatory cell density, corneal hemorrhage, stromal edema, and staining intensity for VEGF and TNF-α were semi-quantitatively scored. Results: Bakuchiol treatment, particularly at 0.28 mg/g, significantly reduced corneal opacity, neovascularization, hemorrhage, and stromal edema compared with the steroid-treated group. Conclusions: Bakuchiol demonstrated promising anti-inflammatory and anti-angiogenic effects and may represent a potential adjunctive treatment for corneal chemical injuries
