PubMed İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8650
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Article Field Correlations in Jet Engine Exhaust Turbulence(Optica Publishing Group (Formerly OSA), 2026) Baykal, Y.Field correlations of collimated Gaussian beams are formulated and examined in jet engine exhaust turbulence. Variations of the field correlations are evaluated against the changes in the parameters of the wireless optical communication link and the jet engine exhaust turbulence. It is found that for all the link and turbulence parameters of interest, as the diagonal distance at the receiver plane increases, the field correlation decreases. Also, at the same diagonal distance from the receiver plane, field correlations tend to become smaller as the receiver points are at a larger distance from the receiver origin, at a smaller source size, wavelength, and inner scale values of jet engine exhaust turbulence. On the other hand, field correlations have a tendency to attain larger values at smaller link length, structure constant, amplitude coefficient for the additional high frequency spectrum area, outer scale of inhomogeneity, and the outer scale values of jet engine exhaust turbulence. © 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.Article Beam Moments of Higher-Order Annular Gaussian Beams in Tissue Turbulence(Optica Publishing Group, 2025) Arpali, Serap Altay; Arpali, Caglar; Baykal, YahyaBeam moments of the laser beam at the receiver plane were analyzed using our previously developed formula for the average light intensity of a higher-order annular Gaussian (HOAG) beam in the presence of biological tissue turbulence. HOAG beam moments are examined for the entities of power-in-the-bucket (PIB) and kurtosis across various tissue types such as the upper dermis (human), liver parenchyma (mouse), intestinal epithelium (mouse), and deep dermis (mouse). Moreover, beam moments are explored considering factors like the strength coefficient of the refractive-index fluctuations and the propagation distance. The PIB values for all HOAG beam modes are found to decrease exponentially and steadily, behaving similar to Gaussian beams as tissue length increases. As turbulence intensity increases, higher-order HOAG beam modes transfer optical energy to the receiver more efficiently than the lower order modes. Kurtosis analysis shows that at intermediate distances, the beam energy is distributed toward the edges, while at longer distances, the energy concentration is lower at the edges than at the center. This trend is reflected in increasing kurtosis values across all HOAG modes and tissue types. Considering the changes in PIB and kurtosis, higher-order HOAG modes transfer energy more conservatively within the tissue. Furthermore, the tissue type with the best transfer of optical power was observed to be the deep dermis (mouse). (c) 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.Article Laser Ablation Device with a Closed-Loop Control System(Optica Publishing Group, 2025) Beldek, Ulas; Erdogan, Kubra; Arpali, Caglar; Baykal, YahyaA laser ablation device with real-time beam power control is designed and implemented. This platform regulates the intensity of the laser beam by continuously measuring its intensity distribution. The quality of the ablation process is optimized through a closed-loop control system that uses a rule-based decision-making approach. The controller generates a starting signal for both the laser power and the motors based on the estimated quality of the ablation. The effects of laser power and light intensity on the formation of microchannels in polymethylmethacrylate material were investigated using the laser beam. The quality of the ablation geometry was assessed through image processing and inspection under a scanning electron microscope. The generated microchannels were analyzed in terms of roughness and residual thermal stress. A comparison of the experimental results with theoretical calculations and simulations revealed that the closed-loop control of laser beam power is effective for material etching and for creating smoother channel profiles. (c) 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.Article Citation - WoS: 5On the Solution of a Parabolic PDE Involving a Gas Flow Through a Semi-Infinite Porous Medium(Amsterdam, 2021) Pop, Daniel N.; Vrinceanu, N.; Al-Omari, S.; Ouerfelli, N.; Baleanu, D.; Nisar, K. S.Taking as start point the parabolic partial differential equation with the respective initial and boundary conditions, the present research focuses onto the flow of a sample of waste-water derived from a standard/conventional dyeing process. In terms of a highly prioritized concern, meaning environment decontamination and protection, in order to remove the dyes from the waste waters, photocatalyses like ZnO or TiO2 nanoparticles were formulated, due to their high surface energy which makes them extremely reactive and attractive. According to the basics of ideal fluid, the key point is the gas flow through an ideal porous pipe consisting of nanoparticles bound one to each other, forming a porous matrix/pipe. The modeling of the gas flow through a porous media is quite valuable because of its importance in investigating the gas-solid processes. The present study is a valid contribution to the existing literature, by developing a nonstandard line method for the partial differential equation, in order to obtain a numerical solution of unsteady flow of gas through nano porous medium. Hence, the physical problem is modeled by a highly nonlinear ordinary differential equation detailed on a semi-finite domain and represents a guidance for several questions originating in the gas flow theory. The findings of this study offered a facile approach to improve an attractive issue related to materials science/chemistry, like synthesis of ZnO or TiO2 nanoparticles forming an ideal nano porous pipe with efficiency in industrial waste waters decontamination.Article Citation - WoS: 2Comparing Hand-Based and Controller-Based Interactions in Virtual Reality Learning: Effects on Presence and Interaction Performance(PeerJ Inc, 2025) Saran, MuratVirtual reality (VR) holds significant promise for enhancing science education by providing immersive and interactive learning experiences. However, the optimal interaction modality within educational VR environments remains an open question. This study investigates the impact of hand-based vs. controller-based interaction on sixth-grade students' sense of presence and interaction performance in a VR science laboratory simulation. Fifty-four sixth-grade students were randomly assigned to either a hand-based interaction group or a controller-based interaction group. Participants completed three interactive science experiments (solar system, electrical circuits, and force/energy) within a virtual laboratory environment designed to mimic their school's physical lab. Presence was assessed using a validated Turkish adaptation of the Presence Questionnaire (PQ), while interaction performance was evaluated using a structured observation form completed by a school teacher. Independent samples t-tests and Mann-Whitney U tests were used to compare the presence and performance scores between the groups. Supplementary analyses explored the effects of gender and prior VR experience. Contrary to expectations, no significant differences were found in either presence (t(49.4) = -0.01, p = 0.992) or interaction performance (t(52) = -1.30, p = 0.199) between the hand-based and controller-based interaction groups. Both interaction modalities yielded comparable levels of self-reported presence and observed performance. However, an unexpected finding emerged regarding performance. A supplementary analysis revealed a significant main effect of gender on performance scores (F(1, 50) = 4.844, p = 0.032), independent of interaction type. Specifically, males demonstrated significantly higher performance than females. This study suggests that, for sixth-grade students engaging in these specific VR science simulations, hand-based and controller-based interactions are equally effective in terms of fostering presence and supporting interaction performance. These findings have practical implications for the design and implementation of VR learning environments, particularly in resource-constrained settings where the reduced maintenance and hygiene concerns associated with hand-based interaction may be advantageous.Article Citation - WoS: 6Citation - Scopus: 6Modeling the Transmission Dynamics of Middle Eastern Respiratory Syndrome Coronavirus with the Impact of Media Coverage(Elsevier, 2021) Fatima, BiBi; Alqudah, Manar A.; Zaman, Gul; Jarad, Fahd; Abdeljawad, ThabetMiddle East respiratory syndrome coronavirus has been persistent in the Middle East region since 2012. In this paper, we propose a deterministic mathematical model to investigate the effect of media coverage on the transmission and control of Middle Eastern respiratory syndrome coronavirus disease. In order to do this we develop model formulation. Basic reproduction number R-0 will be calculated from the model to assess the transmissibility of the (MERS-CoV). We discuss the existence of backward bifurcation for some range of parameters. We also show stability of the model to figure out the stability condition and impact of media coverage. We show a special case of the model for which the endemic equilibrium is globally asymptotically stable. Finally all the theoretical results will be verified with the help of numerical simulation for easy understanding.Article Citation - WoS: 16Citation - Scopus: 16Comparative Application of Wavelet Approaches To Absorption and Ratio Spectra for the Simultaneous Determination of Diminazene Aceturate and Phenazone in Veterinary Granules for Injection(Govi-verlag Pharmazeutischer verlag Gmbh, 2005) Dinç, E; Baleanu, Dumitru; Kanbur, M; Baleanu, D; MatematikA comparison of two wavelet approaches, Daubechies and reverse Biorthogonal, is described for the quantitative resolution of a binary mixture of diminazene aceturate (DIMA) and phenazone (PHE) in veterinary granules for injection without any chemical separation. These two approaches were specified as db4 (a = 180) and rbior3.7 (a = 125) respectively, after testing the signal analysis parameters for the overlapping absorption spectra and ratio spectra. In the first step db4 (a = 180) was applied to the original absorbance data vector of DIMA and PHE. In the second step rbio3.7 (a = 125) was applied to the ratio spectra data vectors of DIMA using the divisor PHE. The same approach was also subjected to the ratio spectra of PHE using the divisor DIMA. The db4 (a = 180) and rbior3.7 (a = 125) calibration graphs were constructed using the transformation values obtained in the wavelet domain. In the method validation, the wavelet calibration functions were tested using synthetic mixtures and the standard addition technique. The simultaneous quantitative analysis of DIMA and PHE in the commercial veterinary preparation was achieved by the elaborated methods. The assay results were compared with each other and good agreement was observed.Article Citation - WoS: 8Citation - Scopus: 8Dimensions of Agitation Based on the Cohen-Mansfield Agitation Inventory in Patients With Dementia(Turkiye Sinir ve Ruh Sagligi dernegi, 2015) Altunoz, Umut; Baştuğ, Gülbahar; Ozel Kizil, Erguvan Tugba; Kirici, Sevinc; Bastug, Gulbahar; Bicer Kanat, Bilgen; Sakarya, Aysegul; Turan, Engin; Kanat Biçer, Bilgen; PsikolojiObjective: The aim of this study was to investigate the dimensions of agitation in dementia patients using the Turkish version of the Cohen-Mansfield Agitation Inventory (CMAI-T). Materials and Method: The study included 100 patients diagnosed as dementia, according to the DSM-IV-TR. The CMAI-T was administered to the patients' caregivers via face-to-face interviews. The Standardized Mini Mental State Examination (SMMSE) was used to assess cognitive functions. The severity of depression and the functional state of the patients were assessed using the Cornell Scale for Depression in Dementia (CSDD) and the Functional Activities Questionnaire (FAQ). Principal component analysis and varimax rotation were used to determine the factor structure of the CMAI-T. Results: Factor analysis of the CMAI-T indicated a 3-factor structure: physically aggressive agitation, verbal agitation, and physically non-aggressive agitation. In 92% of the patients there >= 1 was agitation behavior during the previous 2 weeks. The CMAI-T total and factor scores were negatively correlated with the SMMSE scores, and positively correlated with the CSDD and the FAQ scores. Conclusions: The CMAI-T yielded 3 factors (physically aggressive agitation, verbal agitation, and physically non-aggressive agitation), which indicated the scale had construct validity Agitation behaviors were associated with cognitive dysfunction, symptoms of depression and general level of functioning. Additional research is necessary to identify the predictors of these dimensions in different dementia samples, and to determine the efficacy of therapeutic interventions.Article Citation - WoS: 13Citation - Scopus: 14Continuous Wavelet Transformation Applied To the Simultaneous Quantitative Analysis of Two-Component Mixtures(Govi-verlag Pharmazeutischer verlag Gmbh, 2004) Dinç, E; Baleanu, Dumitru; Baleanu, D; Üstündag, Ö; Aboul-Enein, HY; MatematikIn this paper we developed a graphical method based on Haar (HA) and Mexican (MEX) one-dimensional continuous wavelet transforms and we applied it to a mixture of hydrochlorothiazide (HCT) and spironolactone (SP) in the presence of strongly overlapping signals. Keeping in mind to obtain an appropriately transformed spectrum, we tested several values of the scaling parameter a and the point number of the analysed spectrum in the concentration range of 2-22 mug/ml for both active compounds. The optimal values of the scale parameters and the corresponding frequencies were found to be a = 32 and 0.031 for HA and a = 30 and 0.008 for MEX corresponding to 400 points. HA and MEX methods based on a zero crossing technique were applied to the analysed signal and their regression lines at the selected points were obtained. The validation of the above methods was carried out by analysing different synthetic mixtures containing HCT and SP. MATLAB 6.5. Software was used for one-dimensional wavelet analysis and the basic concepts about wavelet method were briefly explained. The method developed in this paper is rapid, easy to apply, inexpensive and is suitable for analysing the overlapping signals of compounds in their mixtures without any chemical pre-treatment.Article Citation - WoS: 8Citation - Scopus: 8Continuous Wavelet Transform Applied To the Quantitative Analysis of a Binary Mixture(Revista Chimie Srl, 2009) Dinc, Erdal; Baleanu, Dumitru; Baleanu, Dumitru; Üstündag, Ö; Aboul-Enein, HY; MatematikSignal processing methods, continuous wavelet transform (CWT) methods, were proposed for the simultaneous spectral determination of ampicillin sodium (AS) and sulbactam sodium (SS) in their synthetic binary mixtures and pharmaceutical preparations. Firstly, the ratio spectra were obtained by dividing the absorption spectra of a pure compound and its binary mixture by a standard spectrum of one of the compounds in binary mixture. Secondly, the ratio spectra of AS, SS and their samples were processed by the Mexican hat-CWT and Symtles3-CWT (MEX-CWT and SYM3-CWT, respectively). hi this application, the MEX and SYM3 among wavelet families were found to be optimal to obtain the highest spectral recoveries. Calibration graphs of AS and SS in the linear concentration range of 10-70 mu g/mL and 10-55 mu g/mL were obtained by measuring the amplitudes of the transformed ratio signals, respectively. Percent mean recoveries obtained by application of the CWT methods to the synthetic mixtures were found between 99.1 % and 103.6 %. Both SYM3-CWT and MEX-CWT methods were applied to the real samples containing two active compounds and successful results were obtained.