Welcome to Academic Digital Repository
OpenAccess@KU is an academic, open-access repository. It aims to collect, preserve and make Kastamonu University’s scientific output available online, without any or the least financial, legal or technical restrictions, in order to increase the impact and the visibility of the institution and its authors. It was established in 2010 to support the dissemination of knowledge produced by the University members to the wider community both locally and globally.
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Recent Submissions
Recycling concrete sludge waste as a supplementary binder in one-part alkali-activated composites: A comprehensive performance evaluation
(2025.01.01) Demir, B.; Bayraktar, O.Y.; Benli, A.; Türkel, I.; Kara, H.O.; Kaplan, G.
Concrete sludge waste (CS), a by-product of concrete production, poses serious environmental challenges due to its disposal. This study aims to evaluate the potential of unground (UCS) and ground (GCS) CS as partial replacements for ground granulated blast-furnace slag (GBFS) in one-part alkali-activated composites (AACs), thereby advancing sustainable binder systems and reducing reliance on virgin raw materials. The experimental program included flowability, compressive and flexural strength, density, porosity, water absorption, sorptivity, and durability assessments under sulfate attack, freeze-thaw cycling, acid exposure, and elevated temperatures. UCS and GCS replaced GBFS at 5-30 % by weight, activated with sodium metasilicate. Microstructural analysis (SEM, XRD) was conducted to link performance outcomes with matrix development and reaction products. The results showed that UCS reduced flowability significantly (up to -38.5 % at 30 %), while GCS caused only minor changes (-4.6 % at 30 %). At 90 days, UCS at 5-10 % improved compressive strength by 15.5 % and 9.0 %, whereas higher UCS levels caused reductions. All GCS mixtures outperformed the reference, achieving up to 26.2 % strength gains and 46.8 % flexural improvement. Optimal GCS incorporation also enhanced resistance to sulfate, acid, freeze-thaw, and high-temperature exposures, while excessive UCS replacement reduced performance. Microstructural observations confirmed denser matrices with reduced porosity in GCS mixtures, while greenness assessment showed that 10-20 % GCS substitution achieves similar to 3-4 % embodied CO2 savings together with up to 26 % strength gains, thereby combining performance enhancement with sustainability benefits.
A unified analytical framework for chaos, sensitivity, and modulation instability with exact solutions of a newer form of Boussinesq equation
(2025.01.01) Kaplan, M.; Raza, N.; Davletov, I.; Ibragimov, I.; Muminov, S.
This study explores the features and properties of a novel (3+1)-dimensional Boussinesq equation, which models the propagation of shallow water waves in higher-dimensional settings. The equation is significant for understanding nonlinear wave dynamics not only in hydrodynamics but also in fields such as plasma physics, nonlinear optics, and lattice wave theory. The Boussinesq-type equations, incorporating weakly dispersive and weakly nonlinear terms, provide a robust framework for simulating tsunami wave dynamics, particularly in modeling dispersion, wave shoaling, and inundation in coastal regions. A key contribution of this work lies in the application of the generalized exponential rational function method, which has not been previously utilized for this particular equation. Using this method, various exact analytical solutions-including solitary wave solutions-are constructed and graphically illustrated. Furthermore, the study conducts a detailed chaotic analysis, sensitivity analysis and modulation instability analysis to examine the stability characteristics of the obtained wave solutions. The results provide deeper insight into the nonlinear behavior and stability of wave propagation in the (3+1)-dimensional Boussinesq equation framework.
Analytical validation and diagnostic accuracy of a portable hemoglobin/hematocrit meter in cats
(2025.01.01) Tümer, K.Ç.; Deniz, Ö.; Bozaci, S.; Akdenizli, A.K.; Boulaalam, S.
Anemia is a common clinical condition in cats, and accurate measurement of hematocrit (HCT) and hemoglobin (Hb) is essential for diagnosis and monitoring. Conventional laboratory methods are reliable but may not be practical for critically ill patients. Point-of-care (POC) devices offer rapid results using minimal blood volume, however studies evaluating their accuracy in cats remain limited. This prospective study evaluated the analytical and diagnostic performance of the Mission Ultra Hemoglobin/Hematocrit Testing System in 118 client-owned cats. HCT and Hb values obtained with Mission Ultra were compared with reference methods. The microcentrifuge method and the desktop autoanalyzer served as the reference methods for HCT and Hb measurements, respectively. Bland-Altman plots, Passing-Bablok regression, and Receiver Operating Characteristic (ROC) analysis were used to assess agreement and diagnostic accuracy. Mission Ultra showed a negative bias for HCT (-1.8 %, LoA: -5.4 % to 9 %, p < 0.001) and Hb (-0.6 g/dL, LoA: -2 g/dL to 3.2 g/dL, p < 0.001). Passing-Bablok regression revealed constant and proportional bias for HCT and constant bias for Hb. ROC analysis identified optimized thresholds of <29 % for HCT and < 9.6 g/dL for Hb, yielding sensitivities of 92.3 % and 100 %, and specificities of 94.6 % and 94.7 %, respectively. Although Mission Ultra demonstrated good sensitivity and specificity at the established thresholds for HCT and Hb, the observed biases and relatively wide limits of agreement in comparison with the reference methods may limit its reliability in clinical decision-making.
Perceptions of caregivers of children with intellectual disabilities regarding the concept of care: research using metaphor analysis method
(2025.01.01) Kaçan, H.; Durmus, M.
This study aimed to explore the metaphorical perceptions of caregivers of children with intellectual disabilities regarding the concept of care. Data were collected from 122 caregivers primarily responsible for children attending special education programs. The researchers utilized a metaphor questionnaire form to gather responses, prompting participants to complete the sentence "Taking care of a child with intellectual disabilities is like & mldr;& mldr;& mldr;. because & mldr;& mldr;" The participants generated 31 metaphors. The most prevalent ones related to caregiving perceptions included patience and effort (11.5%), fighting spirit (8.2%), and affection (8.2%). These metaphors were categorized into four conceptual categories. Positive metaphors were classified under "divine and sacred perception" and "love and commitment," while negative metaphors fell under "care and dependency" and "patience and resilience." Conclusion: The study underscores the potential impact of caregivers' perceptions on the caregiving burden. Recommendations include providing targeted support to caregivers with negative perceptions, enhancing their coping mechanisms, and offering psychosocial support for stress and anxiety management. Additionally, it is advised to periodically assess caregivers' metaphorical perceptions and conduct similar studies with different samples of caregivers of children with special needs. What is Known:center dot Having a child with an intellectual disability is an emotional burden for all family members, a stressful life experience, and requires ongoing coping strategies.center dot The perceived care burden of family members with mentally disabled children is an important factor affecting the mental health levels of caregivers.What is New:center dot This section should briefly summarize the existing knowledge or consensus on the topic. It should not be a comprehensive literature review, but rather a concise statement of the key findings or established principles.center dot Focus on the most relevant and impactful prior research directly related to your study.
Spontaneous Hematotympanium in a Chronic Lymphocytic Leukemia Patient Receiving Ibrutinib: A Rare Bleeding Complication
(2025) Ünal, S.; Yaşar, M.; Yılmaz, G.