Aksaray Üniversitesi Kurumsal Akademik Arşivi
DSpace@Aksaray, Aksaray Üniversitesi tarafından doğrudan ve dolaylı olarak yayınlanan; kitap, makale, tez, bildiri, rapor, araştırma verisi gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, Üniversitenin akademik performansını izlemeye aracılık eder, kaynakları uzun süreli saklar ve telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Predictive Value of Ionized Calcium Level for Sinus Rhythm Conversion in Adenosine Treatment for Paroxysmal Supraventricular Tachycardia
(Elsevier Inc., 2025) Sert, Ekrem Taha; Kokulu, Kamil; Mutlu, Hüseyin; Gönen, Mustafa Önder; Sert, Zekiye Soykan
Background: Paroxysmal supraventricular tachycardia (SVT) is a recurrent tachydysrhythmia that often leads to emergency department (ED) visits and is commonly treated with intravenous adenosine. Objective: The objective of this paper is to evaluate the relationship between the initial ionized calcium (iCa) level and the achievement of normal sinus rhythm following 6 mg adenosine administration in patients with SVT. Methods: This retrospective, single-center study was conducted in the ED from 2019 to 2023 and included consecutive adult patients diagnosed with SVT who received adenosine treatment. The patients were categorized into two groups based on their response to adenosine treatment. The receiver operating characteristic (ROC) curves were constructed to evaluate the effectiveness of iCa levels in predicting conversion to sinus rhythm. Results: A total of 326 patients were analyzed. The mean iCa level in patients who achieved a sinus rhythm after the initial 6-mg dose was 1.13 ± 0.08 mmol/L, as compared to 1.03 ± 0.11 mmol/L in those who did not respond to this dose, indicating a statistically significant difference (mean difference [95% confidence interval (CI)]: −0.101 [−0.12 to −0.07]). The area under the ROC curve was calculated to be 0.803 (95% CI: 0.752–0.854). An iCa cut-off value of 1.14 mmol/L was determined to be significant for the prediction of achieving sinus rhythm, with a sensitivity of 64.75% (95% CI: 55.6–73.2) and a specificity of 87.75% (95% CI: 83.6–92.7). Conclusion: Our study suggests that the iCa level may be a useful parameter for predicting the response to the 6 mg adenosine dose in patients with SVT.
A computational approach for infrared heating with experimental validation: Surface decontamination process in industrial scale
(Institution of Chemical Engineers, 2025) Erdaş, Ayşe Hümeyra; Karataş, Ozan; Uyar, Rahmi; Erdoğdu, Ferruh
Infrared (IR) processing offers advantages for food processing, and this application is important to revolutionize the food processing for the new era in the industry 5.0. The shorter penetration depth (compared to the microwave and radio frequency processing) limits its application to surface heating, and industrial design of such systems has challenges with the requirement of a computational model. Therefore, the objectives of this study were to develop a computational model and demonstrate the process effects for surface decontamination in an industrial scale system. For this purpose, a computational model was developed and experimentally validated using an aluminum cylinder object and fig samples. Model application for surface decontamination process of figs (for inactivation of Cladosporium spp. and B. cinerea) was demonstrated, and the validated model was used for designing an industrial scale process design. Further research on design and optimization for various processing operations could increase the applicability and effectiveness in industrial scale processes.
Foliar and seed application of salicylic acid and kinetin impacts of the seed yield, oil content and fatty acid composition of safflower (Carthamus tinctorius L.)
(John Wiley and Sons Inc, 2025) Culpan, Emrullah; Gürsoy, Mehtap
Plant growth regulators (PGRs) play important roles in seedling growth, yield, growth, and other parameters in plants. These PGRs include kinetin (K) and salicylic acid (SA). The aim of this study was to investigate the effects of PGRs (K and SA) and their different application methods (foliar spray and seed priming) on safflower (Carthamus tinctorius L.) in field conditions. The present study was conducted in both 2022 and 2023 years as four independent experiments (seed priming with K, foliar application with K, seed priming with SA, foliar application with SA). In the study, four different doses of K (0, 50, 75, and 100 mg L−1) and SA (0, 50, 75, and 100 mg L−1) were used. The experiments were conducted in a randomized complete block design with three replications. In this study, days to emergence, plant height, branch number, head number, number of seeds per head, head diameter, 1000-seed weight, seed yield, oil content, oil yield, and fatty acid composition parameters were investigated. The study's findings indicate that the PGR applications had a significantly improved seed yield, oil content, oil yield, and the examined fatty acids. The oleic acid content, which is a very important parameter for oilseed crops, was positively affected by seed priming with kinetin. In this study, all applications were compared with each other, and it was concluded that seed priming was more effective than the foliar application method. In addition, it was observed that salicylic acid improved the analyzed characters more positively than kinetin.
A numerical comparison of the thermal performances of nano-PCM heat sinks with Fe3O4, MgO, ZnO and xGNP nanoparticles: Key role of increased thermal conductivity
(Elsevier Ltd, 2025) Çiçek, Burcu
A Nano-PCM heat sink model for electronic device cooling was numerically analyzed. RT-35HC was selected as the PCM. Nano-PCMs were created by using different types of nanoparticles, such as Fe3O4, MgO, ZnO and xGNP, added into the PCM at volume fractions of 0.02, 0.04 and 0.06. Nano-PCM heat sinks were numerically simulated in ANSYS under heat fluxes of 3, 4 and 5 kW/m2. Enthalpy-porosity technique was used and UDFs were set in ANSYS for altering the Nano-PCM's thermal conductivity and dynamic viscosity. Results indicate that, by nanoparticles addition, PCM's melting time and heat sink temperature decreased. The reduction in melting time of Nano-PCM were 6.19 %, 10.8 %, and 14.56 % for volume fractions of 0.02, 0.04, and 0.06 for Fe3O4, respectively, relative to PCM only. Initially, the best thermal conductivity was obtained with utilization of xGNP (15 nm), however, with rising temperature over time, thermal conductivity of Nano-PCM with Fe3O4, (10 nm) became the highest. The findings suggest that the lowest base temperature was attained by using Fe3O4, which has the optimum thermal and physical properties, in a 0.02 volume fraction. A detailed and comparative evaluation was provided by addressing various nanoparticles or different sizes of the same nanoparticle for Nano-PCM heat sink.
From garbage to biosorbent: overview raw and hexane purified almond shells for nickel (II) ions removal
(Springer Science and Business Media Deutschland GmbH, 2025) Koçyiğit, Hasan; Gök, Gülden; Çelebi, Hakan
The main purpose of the experimental study is to examine Ni(II) biosorption capacities of raw (RAS) and hexane pretreated (HPAS) almond shells by applying them to wastewater. In the context of the study, batch experiments were conducted to investigate the influence of various parameters, including temperature, RAS and HPAS dosages, pH, and contact time, on the removal efficiency of Ni(II). FTIR and SEM–EDX analyses were performed to determine the functional groups and surface morphology of RAS and HPAS. Adsorption capacities were calculated using different isotherm and kinetic models with the obtained experimental data. It was determined that under optimum conditions (2 g RAS/HPAS, pH 5.87, 10 min, 20 °C), maximum removal efficiencies of Ni(II) for RAS and HPAS were 72% and 81.25%, respectively. The equilibrium adsorption fitted the Langmuir isotherm and pseudo-second-order kinetic. The optimum adsorption capacities for RAS and HPAS were found to be 3.60 and 5.67 mg/g, respectively. Four separate error functions were used to evaluate the suitability of isotherm and kinetic models under equilibrium conditions: MPSD, HYBRID, NSD, and ARE. The findings of the error analysis showed that the HYBRID functions were the smallest in all models. The thermodynamic parameters showed that the process was feasible and exothermic. Experimental results demonstrate that RAS and HPAS are economical and readily available adsorbents for the removal of Ni(II) from aqueous solution. It was also found to give satisfactory results for the removal of Ni(II) without the need for rather expensive modified methods.
