İstanbul Sağlık ve Teknoloji Üniversitesi Kurumsal Akademik Arşivi
DSpace@İSTÜN, Üniversite mensupları 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
Techno-economic and environmental analyses of the use of ammonia-diesel dual fuel in compression ignition engines
(Elsevier, 2025) Karagöz, Yasin; Pusat, Şaban; Tunçer, Erdal; Teksan, A. Emre
In this study, a single-cylinder diesel engine, normally running on diesel fuel, was converted to ammonia-diesel dual fuel. The effects of ammonia fuel at different energy content levels (0 %, 5 %, 10 %, 15 %, and 20 %) were investigated on thermal efficiency, CO, THC, NOx, and smoke emissions. Subsequently, GWP (Global Warming Potential) emission values and tax calculations were performed. Furthermore, economic and exergy analyses were performed using the present value method for converting the engine to ammonia-diesel dual fuel. Finally, the economic analysis was re-conducted by calculating the carbon tax based on the GWP emission value. Based on the results, the lowest GWP emission values were obtained with the addition of ammonia at 10 % energy content.
Effects of blending different ratios of cottonseed oil with diesel fuel in a single-cylinder diesel engine
(AGBIOL, 2025) Tunçer, Erdal
The persistent reliance on internal combustion engines, particularly within the transportation sector, continues to pose significant environmental challenges due to the emission of exhaust gases. This issue has intensified global efforts to identify and develop alternative fuels that can mitigate greenhouse gas emissions associated with fossil fuel consumption. Concurrently, the gradual depletion of petroleum reserves and volatility in fuel prices have introduced economic sustainability concerns. In this experimental study, the impact of blending conventional diesel fuel with 10% and 20% cottonseed oil by volume on engine performance and exhaust emissions was evaluated using a single cylinder direct injection diesel engine. The results demonstrated that the addition of cottonseed oil did not significantly affect engine power output or brake specific fuel consumption. However, a notable decrease in carbon monoxide (CO) emissions was observed, accompanied by an increase in nitrogen oxides (NO) emissions with higher biodiesel ratios. These findings indicate that cottonseed oil–diesel blends up to 20% by volume can be considered a technically viable partial substitute for conventional diesel fuel in compression ignition engines, with tradeoffs in emission characteristics.
Improving oral health in children with disabilities: A preventive home-based care model from Türkiye
(Wiley, 2025) Tunalı, Esra; Ataş, Cafer; Çağ, Yakup; Orhan, Ahmet Lütfullah; Özen, Buğra; Aydınbelge, Mustafa; Tunalı, Mustafa
Background: Children with Special Health Care Needs (CSHCN) face significant challenges in maintaining oral hygiene and accessing dental services due to disabilities. It has been reported that, because of these disadvantages, individuals with special needs experience oral health problems at a higher rate compared to the general population. This study aimed to assess factors influencing oral health in CSHCN within the dental home framework and propose preventive strategies. Methods: A total of 1229 children aged 0-8 years with disability health reports in Istanbul were examined through home visits by mobile dental teams. Caries experience was evaluated using combined indices (dfs + DMFS and dft + DMFT). Data on oral hygiene habits, dietary patterns, parental education level and dental visit history were collected through structured questionnaires. Statistical analyses included Mann-Whitney U, Kruskal-Wallis, chi-square and Spearman's correlation tests (significance set at p < 0.05). Results: A statistically significant positive correlation was found between age and all caries indices (p < 0.01) 0.57. 1% of children reported brushing their teeth, with irregular brushers showing significantly higher caries indices than regular brushers (p < 0.05). Children requiring > 45 min to eat had significantly higher dfs + DMFS (1 surface) (p = 0.036) and dft + DMFT values (p = 0.019). Those consuming snacks > 3 times daily showed significantly higher caries indices across all measures (p < 0.01). Moderate/severe plaque accumulation was detected in 50.5% of participants. Lower parental education levels were significantly associated with higher caries indices (p < 0.01). Conclusions: This study highlights the necessity of an interdisciplinary approach to protect the oral health of CSHCN. The widespread implementation of the dental home model and regular dental check-ups will be a significant step in addressing oral health needs.
Clinical outcomes following medial patellofemoral ligament reconstruction using ultra high-strength 2-mm-wide tape in non-elite athletes
(Elsevier, 2025) Erden, Tunay; Ağır, Muzaffer; Ali, Jotyar; Çelik, Malik; Batar, Suat; Toprak, Ali; Toker, Berkin; Taşer, Ömer
Background: The medial patellofemoral ligament (MPFL) reconstruction is commonly conducted using gracilis, semitendinosus, quadriceps or tensor fascia lata tendon autografts or allografts. This approach, however, can sometimes lead to complications or morbidity at the site from which the graft is harvested. This study reports the clinical outcomes of non-elite competitive athletes who undergone MPFL reconstruction using an ultrahigh strength 2-mm-wide tape. Patients and methods: This retrospective cohort study included 67 non-elite athletes with acute or recurrent lateral patellar instability who underwent surgical treatment between December 2015 and December 2020. Athletes who underwent tibial tubercle osteotomy due to severe patellofemoral arthritis or severe osteochondral damage (kissing lesions or >2.5cm2 ) (1), trochlear dysplasia (Dejour type D dysplasia) (5), open physis (19) and revison MPFL reconstruction (8), were excluded. The remaining 34 athletes were followed postoperatively for a mini mum of 48 months. Results: During the follow-up period, there was only one case and which was revised by adding Fulkerson Osteotomy. Two patients had limited range of motion and joint mobilization was performed under general anesthesia at the end of the second month. The International Knee documentation Committee (IKDC), Kujala, and visual analog scale (VAS) scores showed improvement postoperatively (p < 0.001). Moreover, the mean im provements in IKDC (≈+41), Kujala (≈+33), and VAS (≈− 3.8) scores exceeded the established minimal clini cally important difference (MCID) thresholds, indicating that the outcomes were not only statistically significant but also clinically meaningful for patients. When comparing the pre- and postoperative radiological measure ments, the mean tilt angle and mean congruence angle showed a significant decrease (p < 0.001) Conclusion: Suture tape may be a good alternative to autograft, as it does not cause donor site morbidity. However, its most important disadvantage is its higher cost. Level of evidence: IV; Retrospective case series.
Effect of magnification and press-on force on resin composite polishing
(BioMed Central, 2025) Ünal, Tuna; Korkut, Bora; Tağtekin, Dilek
Objective To evaluate surface roughness (Ra) and gloss (GU) of two resin composites after polishing with two systems, using a novel press-on force guided (PFG) polishing simulator. Materials and methods Eighty specimens were prepared using Essentia Universal (EU) and G-aenial Universal Injectable (GUI) composites. Surface roughness and gloss were assessed by a profilometer (Marsurf Ps10), and a glossmeter (Novo-Curve). They were polished with Sof-Lex and Twist Dia systems with or without magnification and PFG. Each polishing material was used for 30 s. Ra1 and GU1 measurements were repeated by the same operator. Data were analyzed using One-way ANOVA, Three-way ANOVA, and Robust ANOVA with Bonferroni Correction for multiple comparisons and Spearman’s rho Correlation Coefficient (<0.050). Results Higher Ra values were observed in GUI group for Twist Dia (0.33±0.05z ) compared to SofLex (0.22±0.08y ). Roughness was higher when PFG was uncontrolled (0.31±0.07x ), compared to the controlled (0.25±0.09w). No Ra difference was observed in EU group between SofLex (0.33±0.04) and Twist Dia (0.29±0.04)(P=.440). Uncontrolled PFG provided higher gloss for GUI and EU composites (69.7±2.91x , 54.63±18.68x , respectively). Twist Dia presented higher gloss for GUI and EU composites (72.3±2.57z ,58.88±13.73z , respectively). Magnification did not affect the roughness or gloss for both composites (P≥.05). A moderate negative correlation was found between roughness and gloss in GUI (r=-.546)(P<.001), while no correlation was observed in EU (r=-.110)(P=.449). Conclusion Higher surface roughness and gloss were observed with uncontrolled (not constant) press-on force. Even though SofLex may provide a lower surface roughness, Twist Dia can generate a greater surface gloss regardless of the composite type. 3.5X loupe magnification was not effective on surface roughness and gloss within a limited polishing time. Clinical Relevance Press-on force is an important factor affecting the composite polishing quality. Spiral polishing wheels can be advantageous for composite restoration polishing, as they better preserve the secondary and tertiary anatomies and provide a higher gloss. The effect of magnification on composite polishing can be related to the time spent using it.
