Kırşehir Ahi Evran Üniversitesi Kurumsal Akademik Arşivi
DSpace@Kırşehir, Kırşehir Ahi Evran 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 yayınların etkisimi artırmak için telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Lorentz Boundedness Characterization of Commutators of Maximal Operators on Spaces of Homogeneous Type
(Baku Engineering University, 2025) Guliyev, Vagif S.
We study the Lorentz boundedness properties of the maximal commutator operator Mb on the space of homogeneous type and relate this property to spaces of bounded mean oscillations. We also study the Lorentz boundedness properties of the commutators of the maximal operator [b,M] and the commutators of the sharp maximal operator [b,M♯ ] on the space of homogeneous type and relate this property for certain subclasses of spaces of bounded mean oscillations.
Commutator of the Maximal Function in Total Morrey Spaces for the Dunkl Operator on the Real Line
(Institute of Mathematics and Mechanics, National Academy of Sciences of Azerbaijan, 2025) Mammadov, Y.Y.; Guliyev, V.S.; Muslumova F.A.
On the real line, the Dunkl operators Dν are differential-difference operators associated with the reflection group Z2 on R. In this paper, in the setting R we study the commutators of the maximal operator associated with the Dunkl operator [b, Mν] in the total Dν-Morrey spaces Lp,λ,µ (R, dmν). We give necessary and sufficient conditions for the boundedness of the operator [b, Mν] on total Dν-Morrey spaces Lp,λ,µ (R, dmν) when b belongs to BMO(R, dmν) spaces, whereby some new characterizations for certain subclasses of BMO(R, dmν) spaces are obtained.
Using Fish Skin Gelatin Hydrolysate as Stabilizer and/or Emulsifier Agent in Ice Cream Production and Melting, Textural, Rheological, and Sensory Characteristics
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Tekle, Şefik; Göktaş, Hamza; Agan, Cansu; Develioglu-Arslan, Aysen; Tekin-Çakmak, Zeynep Hazal
The increasing global interest in fish consumption leads to a greater generation of fish waste. Fish waste, rich in nutrients such as protein, bioactive compounds, and vitamins, is attracting growing attention for its potential applications in food. In this study, gelatin hydrolysate obtained from fish skin waste was utilized as a stabilizer and/or emulsifier in ice cream production. It was found that gelatin hydrolysate significantly increased the protein content of the ice cream samples. The K and n values in different ice cream compositions varied between 0.009 and 1.012 Pa.sn and 0.356 and 0.863, respectively. The consistency coefficients of samples D1 (sahlep and mono-diglyceride) and D3 (sahlep and gelatin hydrolysate) were almost the same, indicating that the mono-diglyceride was replaced by an equivalent amount of gelatin hydrolysate. All the ice cream mixtures tested showed non-Newtonian, pseudoplastic flow, as indicated by their n values being less than 1. All mixtures demonstrated greater elasticity than viscosity, as their storage modulus (G′) was higher than their loss modulus (G″). In the third interval of 3-ITT, all ice cream mixtures displayed thixotropic behavior, indicating that their viscoelastic properties could be restored after a sudden deformation. The overrun levels of the samples ranged from 9.55% to 21.74%; the use of gelatin hydrolysate resulted in a statistically significant increase (p < 0.05). The highest hardness and stickiness values in the samples were determined in the specific sample containing equal amounts of emulsifier, stabilizer, and gelatin hydrolysate. Furthermore, gelatin hydrolysate prolonged the first dripping time and melting rate of the samples.
Hypoxia Disrupted Serotonin Levels in the Prefrontal Cortex and Striatum, Leading to Depression-like Behavior
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Çalışkan, Hasan; Cihan, Koray Hamza; Koçak, Seda; Karabulut, Gözde; Nalçacı, Erhan
Hypoxia can adversely affect multiple organ systems. This study investigated the impact of intermittent hypoxia on serotonin levels and depression-like behaviors across distinct neuroanatomical regions. Sixteen adult female Wistar albino rats were divided into two groups: control (n = 8) and hypoxia (n = 8). The hypoxia group was exposed to a simulated altitude of 3000 for 5 h daily over 14 days. Behavioral assessments included locomotor activity (open field test) and depression-like behaviors (forced swimming test). Serotonin levels were quantified via ELISA in the prefrontal cortex, striatum, thalamus, hypothalamus, hippocampus, and serum. Intermittent hypoxia did not alter locomotor activity (p > 0.05) but significantly increased depression-like behavior (p < 0.05), accompanied by a pronounced reduction in swimming behavior (p < 0.0001), a marker associated with serotonergic function. Serotonin levels were significantly reduced in the prefrontal cortex (p < 0.005) and striatum (p < 0.05), while no changes were observed in other regions or serum (p > 0.05). These findings demonstrate that intermittent hypoxia induces depression-like behaviors and region-specific serotonin depletion, particularly in the prefrontal cortex and striatum. This underscores the need to evaluate hypoxia-related brain health implications in conditions such as sleep apnea and acute mountain sickness.
Utilising High-Ambient-Temperature Curing in the Development of Low-Calcium Geopolymers
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Karaaslan, Cemal; Şek, Şeyda; Turan, Canan
Geopolymers are typically cured either at ambient temperature (~25 °C) or subjected to short-term heat curing before being stored under ambient conditions until testing. However, in hot-arid regions, the daily ambient temperature may exceed 45 °C during summer months. Therefore, such conditions should also be considered as high ambient curing, and their influence on low-calcium geopolymer performance needs to be investigated. In this study, pumice- and fly ash-based geopolymer mortars were produced to evaluate the effects of different curing regimes. In the pumice-based mixtures, 10 wt% of pumice was replaced with metakaolin to enrich the alumina content. Three curing conditions were applied: ambient curing, high ambient curing, and heat curing. Setting times of geopolymers were determined based on each curing regime. Physical properties, including density, water absorption, and sorption coefficient, were assessed. Compressive strength development was evaluated over 90 days. In addition, durability performance was assessed through water resistance, freeze–thaw durability, and resistance against sulphuric and hydrochloric acid. Fourier transform infrared spectroscopy and X-ray diffraction confirmed that geopolymerisation reactions continued significantly up to 90 days under high ambient curing, while mercury intrusion porosimetry showed a reduction in porosity. These findings explain the continuous increase in compressive strength. Pumice-based geopolymers cured under this condition exhibited significantly better long-term strength than those cured under other regimes. High ambient-cured fly ash-based geopolymers, a 3-day strength of 40.3 MPa was achieved, eliminating the need for heat curing. Thus, high ambient curing enables the in situ use of these geopolymers and offers a cost-effective and eco-friendly alternative.
