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Novel Fractional Boole's-Type Integral Inequalities via Caputo Fractional Operator and Their Implications in Numerical Analysis
Get PDFThe advancement of fractional calculus, particularly through the Caputo fractional derivative, has enabled more accurate modeling of processes with memory and hereditary effects, driving significant interest in this field. Fractional calculus also extends the concept of classical derivatives and integrals to noninteger (fractional) orders. This generalization allows for more flexible and accurate modeling of complex phenomena that cannot be adequately described using integer-order derivatives. Motivated by its applications in various scientific disciplines, this paper establishes novel n-times fractional Boole's-type inequalities using the Caputo fractional derivative. For this, a fractional integral identity is first established. Using the newly derived identity, several novel Boole's-type inequalities are subsequently obtained. The proposed inequalities generalize the classical Boole's formula to the fractional domain. Further extensions are presented for bounded functions, Lipschitzian functions, and functions of bounded variation, providing sharper bounds compared to their classical counterparts. To demonstrate the precision and applicability of the obtained results, graphical illustrations and numerical examples are provided. These contributions offer valuable insights for applications in numerical analysis, optimization, and the theory of fractional integral equations
A Qualitative Study of Perceptions of Privacy in Interpersonal Communication
Get PDFBA review of extant literature on digital privacy reveals a paucity of attention to the nexus between privacy and interpersonal communication, particularly among university students. This study explores the evolution of students’ interpersonal communication practices on Instagram, employing a phenomenological approach to examine privacy perceptions. The qualitative phenomenological method was selected to analyze individuals’ subjective experiences and actions related to privacy in digital interactions. A notable limitation of the study is its focus on privacy perceptions within Instagram, rather than a broader analysis of digital privacy across social media platforms. The selection of Instagram as a subject of study was driven by its widespread use and emphasis on visual content, which was deemed relevant during the research period. The findings indicate that participants place significant importance on protecting their privacy, and while users tend to observe others on Instagram, they are more reluctant to share personal content. The study also reveals that Instagram blurs the boundaries between public and private spaces. Although participants acknowledge privacy as an individual responsibility, they show less concern for controlling others’ posts, reflecting a one-sided perception of privacy. In conclusion, the impact of social media on privacy needs reconsideration at both the individual and societal levels. The continuous online presence on social media platforms challenges traditional privacy boundaries, leading to new dynamics in personal information sharing. This study underscores the necessity of reevaluating digital privacy in the evolving landscape of social media communication. © 2025 Elsevier B.V., All rights reserved
Utilisation of Carbon Quantum Dots from Hazelnut Husk for Folic Acid (FA) Detection: An Innovative Approach
Get PDFThis study presents the development of a carbon quantum dot (CQD)-based fluorescence sensor for the accurate quantification of Folic Acid (FA). CQDs were synthesized from hazelnut husk using a solvothermal method and functionalized with silver ions to create an off-state fluorescence system. Upon mixing FA solutions, prepared from pure water and pharmaceutical tablets, with phosphate-buffered saline (PBS) and off-state CQDs, fluorescence emission was restored (on-state) in a concentration-dependent manner when excited at 360 nm. A strong linear relationship was observed between FA concentration and fluorescence intensity, with an R-2 value of approximate to 0.994. The samples were categorized into low (0.0376-0.7533 mu M) and high (0.7533-7.533 mu M) concentration groups for improved accuracy, achieving mean percentage errors of 0.70% and 1.85%, respectively, at concentrations as low as 0.565 mu M. This CQD-based sensor demonstrated rapid, cost-effective, and highly sensitive detection capabilities, making it a promising alternative for FA quantification in biomedical and nutritional applications. Furthermore, the use of sustainable raw materials, such as hazelnut husk, highlights the eco-friendly and practical advantages of this method over conventional techniques
Kistik Fibrozisli Çocuklarda Antibiyotik Direncindeki Değişimler ve Klinik Sonuçlar Üzerindeki Etkisi
Get PDFAim: Antibiotics have an important role in the treatment of cystic fibrosis (CF) lung disease. Antibiotic resistance, especially multidrug resistance (MDR), increases in CF. This study aimed to determine whether there is a change in antibiotic resistance of pathogens isolated from the respiratory tract specimens of CF patients and to evaluate the relationship between the antibiotic resistance and patients’ clinical status and pulmonary function. Material and Methods: Thirty-nine CF patients with identified microorganisms in respiratory tract specimens from August 2010 through December 2016 were included in the study. 333 respiratory cultures taken from 39 CF patients were analyzed retrospectively. Results: Methicillin-sensitive S. aureus (MSSA) was isolated from 122 (31.0%) cultures, P. aeruginosa from 97 (24.7%), and methicillin-resistant S. aureus (MRSA) from 22 (5.6%). The prevalence of MSSA (p=0.020) and MRSA (p=0.010) increased from 2010 to 2016, while the prevalence of P. aeruginosa and other microorganisms did not increase. MDR-S. aureus and MDR-P. aeruginosa prevalence did not change, but MRSA prevalence increased over the years (p=0.001). There was a significant relation between the antibiotic resistance and acute pulmonary exacerbations, pulmonary examination findings, loss in weight and height percentile. As the antibiotic resistance increased, FEV1, FVC, FEV1/FVC, PEF, and FEF25-75 were significantly decreased. The use of long-term azithromycin or inhaled antibiotics was not associated with antibiotic resistance. Conclusion: In CF patients, resistance to antibiotics increased over the years. It is important to obtain respiratory tract cultures regularly and initiate rational antibiotic treatment based on culture results. © 2025 Elsevier B.V., All rights reserved
Hermite-Hadamard-Mercer type inequalities for fractional integrals: A study with h-convexity and ψ-Hilfer operators
Get PDFIn this paper, we first prove a generalized fractional version of Hermite-Hadamard-Mercer type inequalities using h-convex functions by means of psi-Hilfer fractional integral operators. Then, we give new identities of this type with special functions depending on psi. Moreover, we establish some new fractional integral inequalities connected with the right- and left-hand sides of Hermite-Hadamard-Mercer inequalities involving differentiable mappings whose absolute values of the derivatives are h-convex. For the development of these novel integral inequalities, we utilize h-Mercer inequality and H & ouml;lder's integral inequality. These results offer the significant advantage of being convertible into classical integral inequalities and Riemann-Liouville fractional integral inequalities for convex functions, s-convex functions, and P-convex functions
Friction stir spot welding of pe material
Get PDFPlastik malzemelerin birleştirme ve kaynak teknolojilerindeki gelişmeler, hem sanayi uygulamaları hem de akademik araştırmalar açısından büyük önem taşımaktadır. Özellikle Sürtünme Karıştırma Kaynağı (SKK) ve ondan türetilen Sürtünme Karıştırma Nokta Kaynağı (SKNK) yöntemleri, harici ısıtıcı veya yapıştırıcı gerektirmeden, tüketilmeyen döner takımlar aracılığıyla kaynak yapma olanağı sunmalarıyla öne çıkmaktadır. Hafif yapıların ön plana çıktığı günümüz endüstrisinde, metal yerine polimer kullanımının yaygınlaşmasıyla birlikte, polietilen (PE) gibi termoplastik malzemeler SKNK yöntemiyle başarılı şekilde birleştirilebilmektedir. Bu tez çalışmasında, 4 mm kalınlığında PE levhalar üzerinde farklı takım geometrileri ve işlem parametreleri ile deneyler gerçekleştirilmiş; optimum karıştırma süresi belirlenmiştir. Çekme testleri sonucunda, birinci kaynak takımıyla elde edilen 2412 N'lik çekme kuvveti, asıl numunenin 2650 N'lik değeriyle karşılaştırıldığında %91 oranına ulaşmıştır. İkinci kaynak takımı 2176 N ile %82,12, üçüncü takım ise 2356 N ile %88,9 oranında başarı sağlamıştır. Bu veriler, takım geometrisi, dönme hızı, dalma derinliği ve karıştırma süresi gibi parametrelerin kaynak performansı üzerindeki etkisini net biçimde ortaya koymaktadır. Ayrıca, çeşitli araştırmalar da bu parametrelerin bağlantı kalitesine doğrudan etki ettiğini göstermekte; optimum kombinasyonun seçimiyle güçlü ve homojen kaynak bağlantılarının elde edilebildiği belirtilmektedir. Çalışmada kırılma yüzeyleri, kopma bölgeleri ve enine kesitler optik mikroskop ile incelenerek kaynak yapısının detaylı analizi yapılmıştır. Sonuç olarak, SKNK yönteminin polimer malzemelerde güvenilir ve yüksek performanslı kaynaklar üretmede etkin bir yöntem olduğu bir kez daha kanıtlanmıştır.Developments in the joining and welding technologies of plastic materials hold great significance for both industrial applications and academic research. In particular, Friction Stir Welding (FSW) and its derivative method, Friction Stir Spot Welding (FSSW), have come to the forefront due to their ability to perform welding without the need for external heating or adhesives, using non-consumable rotating tools. In today's industry, where lightweight structures are increasingly prioritized, the use of polymers instead of metals has become widespread, and thermoplastic materials such as polyethylene (PE) can be successfully joined using the FSSW method. In this thesis study, experiments were conducted on 4 mm thick PE sheets using various tool geometries and process parameters, and the optimum stirring time was determined. According to the results of the tensile tests, the first tool achieved a maximum tensile strength of 2412 N, corresponding to 91% of the reference specimen's 2650 N value. The second tool achieved 2176 N (82.12%), while the third reached 2356 N (88.9%). These findings clearly demonstrate the influence of tool geometry, rotational speed, plunge depth, and stirring time on weld performance. Furthermore, previous studies have also shown that these parameters directly affect joint quality, and that selecting the optimum combination allows for the formation of strong and homogeneous welds. In this study, fracture surfaces, failure zones, and cross-sections were examined in detail using an optical microscope, providing an in-depth analysis of the weld structure. As a result, it has once again been confirmed that the FSSW method is an effective, reliable, and high-performance technique for joining polymer materials
TWO RESULTS FOR POSITIVE SOLUTIONS OF A FRACTIONAL DIFFERENTIAL EQUATION INVOLVING p-LAPLACIAN OPERATORS
Get PDFWe prove two results regarding the existence of positive solutions for a p-Laplacian fractional high-order differential problem with initial conditions. We do this by applying the cones technique, lower and upper solutions, and the Leray–Schauder alternative. A detailed example illustrates one of the results. © 2025 Elsevier B.V., All rights reserved
Some technological properties of plywood made from heat treated veeners
Get PDFBu çalışmada, Titrek Kavak (Populus deltoites) ile Doğu Kayını (Fagus orientalis Lipsky) ve odunlarından elde edilen 1.2 mm kalınlığındaki kaplama soyma yöntemi ile elde edilmiş kaplamalara ısıl işlem uygulanarak 3 tabakalı kontrplak üretilmiştir. İki farklı tutkal türü (fenol formaldehit ve üre formaldehit) kullanılarak üretilmiş kontrplakların mekanik ve fiziksel özellikleri değerlendirilmiştir. Standartlara göre elde edilen sonuçlar istatistiksel olarak analiz edilmiştir. Isıl işlem, kontrplakların kalınlık artımında %67,3 oranında belirgin bir azalmaya neden olarak boyutsal stabiliteyi iyileştirme potansiyeli sunarken, su alma miktarında da %40,6 oranında önemli bir düşüş sağlamıştır. Bununla birlikte, ısıl işlem çekme-makaslama direncinde %14,6 ve eğilme direncinde %13 oranında bir azalmaya yol açmış, ancak elastikiyet modülü üzerinde önemli bir kayba neden olmamıştır. Tutkal türü ve ağaç türünün kalınlık artımı üzerindeki etkisi istatistiksel olarak önemsiz bulunurken, fenol formaldehit tutkalı, üre formaldehit tutkalına kıyasla daha yüksek eğilme direnci ve yapışma direnci sağlamıştır. Isıl işlemli kontrplakların direnç özelliklerinde genel bir azalma gözlemlenmiş olmakla birlikte, bu azalmaların birçok kullanım alanı için önemsiz olabileceği belirlenmiştir. Özellikle ısıl işlem, kontrplakların suya karşı direncini artırarak boyutsal stabiliteyi iyileştirmiş ve bu özelliklerin, düşük nem oranına sahip iç mekân uygulamalarında avantaj sağlayabileceği görülmüştür.In this study, three-layer plywood panels were produced by applying thermowood to 1.2 mm thick rotary-cut veneer sheets obtained from Oriental Beech (Fagus orientalis Lipsky) and Aspen (Populus deltoites) wood. The mechanical and physical properties of the plywood panels, produced using two different adhesive types (phenol-formaldehyde and urea-formaldehyde), were evaluated, and the results were statistically analyzed. Thermal treatment has led to a significant reduction in the thickness swelling of plywood by 67.3%, offering potential improvements in dimensional stability, while also resulting in a notable decrease in water absorption by 40.6%. However, thermal treatment caused a reduction in tensile-shear strength by 14.6% and bending strength by 13%, although no significant loss was observed in the modulus of elasticity. The effect of adhesive type and wood species on thickness swelling was found to be statistically insignificant, whereas phenol formaldehyde adhesive provided higher bending strength and bond strength compared to urea formaldehyde adhesive. Although a general decrease in the strength properties of thermally treated plywood was observed, these reductions were determined to be negligible for many applications. In particular, thermal treatment enhanced the water resistance of plywood and improved dimensional stability, suggesting that these properties could offer advantages in interior applications with low moisture levels
Did Increase of Rates of Sudden Hearing Loss During COVID-19?
Get PDFObjective: This study aims to assess the impact of the COVID-19 pandemic on cases of sudden hearing loses (SHL). Method: We examined two patient groups diagnosed with SHL at D & uuml;zce University Medical Faculty Hospital and D & uuml;zce Ataturk State Hospital in Turkey. The first group, diagnosed between March 2019 and March 2020, represents pre-Covid-19. The second group includes patients diagnosed from March 2020 to March 2021, corresponding to the initial year of the Covid-19 pandemic in this region. We evaluated patient numbers, age, and gender across these groups to identify any increase in SHL cases potentially associated with the pandemic. Results: The ratio of SHL cases per population in Group 1 was 51 out of 450,000, or approximately 0.011333. In Group 2, this ratio was 32 out of 450,000, or roughly 0.007111. Statistical analysis (p=0.037) revealed a notably higher SHL rate in the pre-Covid-19 period than during the pandemic. Conclusions: The suggested etiological explanations for SHL remain hypothetical. Although COVID-19 has been widely considered a possible factor, our findings do not support increased SHL cases due to the virus
Evaluation of Osteoarticular Involvement Associated with Brucellosis in Children
Get PDFAim: Brucellosis is a significant public health problem with high morbidity. Its most frequent complication is osteoarticular involvement. The study aimed to evaluate the relationship of osteoarticular involvement with clinical features and prognosis in children with brucellosis. Material and Methods: This retrospective study included pediatric patients between the ages of 1 and 18 years who were hospitalized and diagnosed with brucellosis between 2015 and 2020, and were regularly followed up. Aand all their findings and osteoarticular involvement data within the last two years were recorded. Clinical features, laboratory findings, osteoarticular involvement, and relapse rates of the patients were evaluated. Results: A total of 80 patients were included study. During the follow-up period, relapse developed in 14 (17.5%) patients. The most commonly affected joints were right (40%, n=32) and left (26.3%, n=21) hips, then right (27.5%, n=22) and left (23.8%, n=19) knees. Shoulder joint involvement rates and C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), alanine transaminase (ALT), and aspartate aminotransferase (AST) levels were statistically significantly higher in the relapse group (p=0.016, p=0.003, p=0.001, p<0.001, p<0.001, respectively). There was no significant difference in demographic characteristics, clinical features, and treatment responses of the patients between age groups, except weakness and sweating complaints that were high among older children (p=0.036). Conclusion: High admission ALT, AST, CRP, and ESR levels in brucellosis cases with osteoarticular involvement and the presence of shoulder joint involvement, albeit rarely, can be a warning sign in terms of relapse. Patients should be closely followed up in terms of brucellosis complications