Assessment of the influence of abrasive water jet drilling parameters on glass fiber-reinforced polymer composites

In this study, the effect of abrasive waterjet (AWJ) drilling of glass fiber-reinforced polymer (GFRP) composites (0 degrees/90 degrees fiber orientations) on the kerf taper (T) and roundness error (Re) of the holes was investigated. The experiments were carried out using an abrasive waterjet designed with a Taguchi L16 orthogonal array. The following waterjet processing parameters were selected: water pressure, stand-off distance, and feed rate. Statistical analyses were conducted using analysis of variance (ANOVA), signal-to-noise (S/N) ratios, and Taguchi-based gray relational analysis (GRA) to investigate the effects of processing parameters on kerf taper and roundness error. An Artificial Neural Network (ANN) model was created for the estimation of the experimental data, and the generated model was executed with minimum error and maximum accuracy. The analysis revealed that water pressure was the most influential parameter, contributing 87.75% to Re and 85.15% to T, followed by stand-off distance (11.00% for Re and 13.02% for T). Based on the parameters selected through GRA, the optimum conditions (5300 bar water pressure, 1 mm stand-off distance, 3000 mm/min traverse feed rate, 10 mm hole diameter) produced a minimum Re of 0.709 mm and a T of 0.420 degrees

Kavramsal Tutarlılığın Önemi Bağlamında Gazzâlî’nin Müşterek Lafızlara Yaklaşımı

Türkçe çok anlamlılık manasına gelen “iştirâk-ı lafzî” veya “müşterek lafız”, telaffuzu aynı, anlamı farklı olan kelimeler için kullanılan bir kavramdır. Naslarda veya bir ilme ait metinlerde geçen ifadelerin doğru anlaşılmasında müşterek lafızları ve anlamlarını bilmek önemlidir. Makalenin amacı, Gazzâlî’nin kelâmî konulardaki “müşterek lafız”larla ilgili metodunun ortaya çıkarılmasıdır. Bunun için onun müşterek lafız olduğunu söylediği; iman, Kur’an, kadim, akıl, bilgi, nefs ve mecâz kelimelerini nasıl açıkladığının tespit edilmesi hedeflenmektedir. Bu amaç ve hedefler aynı zamanda kavramsal tutarlılığın önemini ortaya çıkaracak ve günümüzde kullanılan kavramlara yönelik bir perspektif sunacaktır. Gazzâlî, müşterek lafzın normalde kullanılan bir anlamının olamayacağını, yalın halde kullanıldığında hangi anlamın kastedilmiş olduğunun bilinemeyeceğinin altını çizer. Dolayısıyla müşterek lafız herhangi bir karine olmadan zikredilirse veya karinenin anlama delaleti kesin değilse anlamın tespiti ictihada dayanacaktır. O, yukarıda zikredilen kavramların her birisinin farklı anlamlara gelebildiğini belirtmektedir. Dolayısıyla bazı mezheplerin bu kavramlar üzerindeki ihtilafının lafzî bir ihtilaf olabileceği anlaşılmaktadır

Novel Conservative Therapies in Migraine Management: The Impact of Fascia Exercises in a Randomized Controlled Trial

Background/Objectives: Migraine is a complex neurological disorder often associated with autonomic nervous system (ANS) dysfunction. This study aimed to evaluate the effects of fascia exercises on migraine symptoms and explore their potential as a novel conservative treatment approach. Methods: A prospective, randomized controlled trial was conducted with 30 migraine patients who were randomly assigned to a treatment group (fascia exercises) or a control group (conventional physiotherapy). Both groups underwent a six-week intervention consisting of two sessions per week. Pain intensity, migraine-related disability, sleep quality, anxiety, depression, heart rate variability (HRV), and patient satisfaction were assessed before and after the intervention using validated scales. Results: Significant improvements in pain intensity, attack frequency and duration, migraine-related disability, sleep quality, and anxiety levels were observed in both groups (p < 0.05). However, the treatment group demonstrated a more pronounced reduction in depression scores compared to the control group (p < 0.05). While no significant changes in HRV parameters were detected in either group, patient satisfaction was significantly higher in the treatment group (p < 0.05). Conclusions: Fascia exercises represent a promising complementary therapy for migraine management, offering significant improvements in both physical and psychological symptoms. While immediate effects on HRV were not evident, the potential to modulate autonomic balance and address migraine pathophysiology warrants further exploration. These findings highlight the value of fascia exercises as a low-cost, non-invasive approach, emphasizing the need for further research to confirm their long-term clinical benefits and integration into migraine treatment protocols

Pupillographic evaluation accompanying structural and functional assessment of the optic nerve in patients with Parkinson's disease

Background To evaluate static and dynamic pupillary functions, contrast sensitivity, and retinal nerve fiber layer (RNFL) thickness in patients with Parkinson's disease. Methods The study included 25 right eyes of patients with Parkinson's disease (mean age: 67.88 +/- 9.40 years) and 26 right eyes of age- and sex-matched healthy controls (mean age: 64.15 +/- 7.60 years). Following the measurement of visual acuity and intraocular pressure, the RNFL thickness of the right eye was assessed using optical coherence tomography (Optovue, Inc., Fremont, CA, USA), and contrast sensitivity was measured with the CSV-1000E (Vector Vision, Dayton, OH, USA). Following a 5-minute period of dark adaptation, both static and dynamic pupillographic parameters were assessed using the Sirius corneal topography device (Sirius, CSO, Florence, Italy). Results There was no statistically significant difference between the groups in terms of age and sex (p = 0.126 and p = 0.579, respectively). RNFL thickness in the superior, inferior, nasal, and temporal quadrants of the right eye were as follows for Parkinson's and control groups, respectively: 133.6 +/- 18.03 vs. 144.73 +/- 17.44 mu m (p = 0.03), 122.0 +/- 14.47 vs. 134.96 +/- 25.28 mu m (p = 0.031), 67.76 +/- 12.05 vs. 74.65 +/- 12.05 mu m (p = 0.047), and 66.36 +/- 8.72 vs. 72.77 +/- 14.0 mu m (p = 0.057). A statistically significant thinning was observed in all quadrants except the temporal quadrant in Parkinson's patients (Fig. 1). Contrast sensitivity was significantly lower in the Parkinson's group across all spatial frequencies compared to controls (p = 0.03, 0.01, 0.05). Similarly, in dynamic pupillography, the pupil diameters at 0, 2, 4, 8, 12, and 16 s were smaller in the Parkinson's group, but no statistically significant differences were found between the groups (p > 0.05) (Fig. 3). Conclusions While a significant reduction in RNFL thickness and contrast sensitivity was observed in patients with Parkinson's disease, static and dynamic pupillographic parameters did not differ significantly between the groups. Therefore, the prognostic utility of pupillography in Parkinson's disease remains inconclusive and should be further investigated in larger and longitudinal studies

The investigation of mechanical properties of 439 DX51D quality sheets joined by spot resistance welding

Endüstride, özellikle imalat sektöründe, çeşitli çelik malzemeler yaygın olarak kullanılmaktadır. Üretim sırasında, bu çelik parçaların belirli noktalarda birleştirilmesine sıklıkla ihtiyaç duyulmaktadır. Bu birleştirme için seri imalat sektöründe en yaygın tercih edilen birleştirme yöntemlerinden bazıları nokta direnç kaynağı yöntemidir. Bu ince sac malzemelerin, dayanıklı ve güvenilir bir şekilde birbirine kaynaklanması amacıyla yaygın olarak kullanılır. 439 kalite paslanmaz çelik levha, oksidasyona karşı direnci fazladır ,800-900 dereceye ulaşan sıcaklık dayanımına sahiptir. Yüksek sıcaklıklarda sağlamlığı ve kaynak potansiyeli sayesinde sürekli olarak kullandığımız su ısıtıcıları gibi küçük ev aletlerinde, sıcaklığın sürekli değiştiği araç egzoz yapımı ve parçalarında, çamaşır makineleri, otomotiv sektörü ve en önemlisi gıda sektöründe sıkça kullanılabilen ferritik paslanmaz çeliktir. DX51 galvaniz sac, sıcak daldırma galvanizleme yöntemi ile kaplanmıştır. Bu işlem, çeliği korozyona karşı korumak için çinko kaplama uygulanması anlamına gelir. Genellikle iki tarafı da kaplanmıştır. DX51, genellikle düşük karbonlu çelikten (LC) üretilir ve ticari kalitede olarak kullanılır. Çelik kalitesi, DX51D ve DX51D+Z gibi belirli kimyasal kompozisyon ve mekanik özelliklere sahip alt sınıflarla da belirtilebilir. Yapı inşaatı, otomotiv, beyaz eşya, elektrikli ev aletleri, ambalaj, su ve gaz boru hatları, otomotiv parçaları, çatı kaplama, dış cephe kaplamaları gibi birçok farklı endüstriyel ve ticari uygulamada kullanılabilir. Bu çalışmada, farklı parametreler kullanılarak 439 ve DX51D çelikleri elektrik direnç nokta kaynağı yöntemiyle birleştirilmiştir. Birleştirilen numuneler üzerinde metalografik incelemeler yapılmış ve mekanik testler uygulanmıştır. Numuneler, elektrik direnç nokta kaynağı ile üç farklı amper, üç farklı baskı kuvveti ve üç farklı bekleme süresi kullanılarak hazırlanmıştır. Elektrik direnç nokta kaynağında, elektrotlardan geçen akım, elektrotların iş parçasına uyguladığı kuvvet ve kaynak süresi en önemli temel faktörlerdir. Bu faktörlerin birbirleri ile kombinasyonları ve uygulanma miktarları kaynak kalitesini belirler. Kaynağın kalitesi birleştirilecek parçaların mekanik dayanımına doğrudan etki eder. İlgili kaynak parametrelerin ferritik ve galvanizli çelikler üzerinde dayanım, sertlik ve mikroyapı özellikleri incelenerek uygun kaynak parametrelerinin belirlenmesi hedeflenmiştir. Kaynaklı numunelerin mekanik ve mikroyapı özelliklerini belirlemek amacıyla çekme testi, sertlik ölçümü, mikroyapı analizi ve kaynak nüfuziyeti incelemeleri gerçekleştirilmiştir.In industry, especially in the manufacturing sector, various steel materials are widely used. During production, there is often a need to join these steel parts at certain points. For this joining, some of the most widely preferred joining methods in the mass production sector are spot resistance welding. It is widely used for welding these thin sheet materials together in a durable and reliable way. 439 grade stainless steel plate has high resistance to oxidation, temperature resistance reaching 800-900 degrees. Thanks to its robustness and welding potential at high temperatures, it is ferritic stainless steel that can be used frequently in small household appliances such as water heaters that we use continuously, vehicle exhaust construction and parts where the temperature changes constantly, washing machines, automotive sector and most importantly in the food sector. DX51 galvanised sheet is coated with hot dip galvanising method. This process means applying zinc coating to protect the steel against corrosion. It is usually coated on both sides. DX51 is usually produced from low carbon steel (LC) and used as a commercial grade. The steel grade can also be specified by sub-grades with specific chemical composition and mechanical properties, such as DX51D and DX51D+Z. It can be used in many different industrial and commercial applications such as building construction, automotive, white goods, electrical appliances, packaging, water and gas pipelines, automotive parts, roofing, exterior cladding. In this study, 439 and DX51D steels were joined by electric resistance spot welding method using different parameters. Metallographic investigations and mechanical tests were carried out on the joined specimens. The specimens were prepared by electric resistance spot welding using three different amperes, three different press forces and three different dwell times. In electric resistance spot welding, the current flowing through the electrodes, the force applied by the electrodes to the workpiece and the welding time are the most important basic factors. The combination of these factors with each other and the amount of application determine the quality of the weld. The quality of the weld directly affects the mechanical strength of the parts to be joined. It is aimed to determine the appropriate welding parameters by investigating the strength, hardness and microstructure properties of ferritic and galvanised steels. Tensile test, hardness measurement, microstructure analysis and weld penetration investigations were carried out to determine the mechanical and microstructural properties of the welded specimens

Investigation of electric vehicle charging station installation and management system in a public institution in Mardin province

Sınırsız olmayan fosil yakıtlar gün geçtikçe azalmakta, yerini yenilenebilir enerji kaynaklarına bırakmaya başlamıştır. Ulaşım sektöründe fosil yakıtla çalışan araçlar karbon emisyonuna neden olduklarından çevreyi kirletmekte ve yerlerini doğa dostu elektrikli araçlara bırakmaktadır. Gelişmiş ülkeler özellikle Amerika Birleşik Devletleri ve Çin elektrikli araçlar konusunda rekabet yarışı içerisindedirler. Türkiye ve diğer dünya ülkelerinde de elektrikli araçlar üretilmeye başlanmış ve elektrikli araçlara olan yönelim hızla artmıştır. Ancak elektrikli araç kullanıcılarının elektrikli araç şarj istasyonlarına ulaşım endişesi bulunmaktadır. Bundan dolayı elektrikli araç şarj istasyon sayısı ve ulaşılabilirliği önem arz etmektedir. Günümüzde hızlı elektrikli araç şarj istasyonlarının güçleri 400 kW'ın üstündedir. Bu yüksek güçlü şarj istasyonları ve bu istasyonlara bağlanarak şarj olan elektrikli araçlar şebeke üzerinde aşırı bir yükün oluşmasına neden olabilecektir. Bu çalışmada Mardin ili merkez ilçesinde kamu kurumlarının bulunduğu Valilik yerleşkesinde bulunan ve sadece kamu personelinin araçlarının park edildiği, enerjisini valilik yerleşkesini besleyen özel trafodan alan valilik otoparkına senaryonlar halinde, 22 kW, 100 kW ve 180 kw'lık elektrikli şarj istasyonlarına batarya doluluk oranı %20 olan ve %100' e kadar şarj olacak elektrikli araçlar bağlanarak Matlab Simulink programı ile trafodan çekilen yük ve akım miktarları ölçülmüştür. Gerilim düşümü hesaplanmıştır. Trafonun maksimum %80 doluluk oranına göre sonuçlar analiz edilmiştir. Ayrıca trafonun %80 doluluk oranını aşmayacak şekilde valilik otoparkına kurulabilecek elektrikli araç şarj istasyon sayısı ve tipleri belirlenmiştir. Trafo değeri iki katına çıkarıldığında sonuçlar karşılaştırılmış, elde edilen veriler ayrıntılı olarak analiz edilmiştir.Unlimited fossil fuels are decreasing day by day and have begun to be replaced by renewable energy sources. In the transportation sector, fossil fuel-powered vehicles pollute the environment as they cause carbon emissions and are being replaced by environmentally friendly electric vehicles. Developed countries, especially the United States and China, are in a competitive race for electric vehicles. Electric vehicles have also begun to be produced in Turkey and other countries around the world, and the trend towards electric vehicles has increased rapidly. However, electric vehicle users have concerns about access to electric vehicle charging stations. Therefore, the number of electric vehicle charging stations and their accessibility are important. Today, the power of fast electric vehicle charging stations is over 400 kW. These high-power charging stations and electric vehicles that are charged by connecting to these stations can cause an excessive load on the network. In this study, in the governorate campus where public institutions are located in the central district of Mardin province, electric vehicles with a battery charge rate of 20% and that will charge up to 100% were connected to the governorate parking lot, which is located in the governorate campus where only public personnel vehicles are parked and receives its energy from the special transformer that feeds the governorate campus, in scenarios, and the load and current amounts drawn from the transformer were measured with the Matlab Simulink program. The voltage drop was calculated. The results were analyzed according to the maximum 80% charge rate of the transformer. In addition, the number and types of electric vehicle charging stations that can be installed in the governorate parking lot were determined so that the transformer would not exceed 80% charge rate. The results were compared when the transformer value was doubled, and the obtained data were analyzed in detail

Monitoring stress using a wearable device and measuring satisfaction during high-fidelity perinatal simulation: A randomized controlled study

Aim: To continuously monitor midwifery students' physiological stress during high-fidelity perinatal simulation using a wearable device (Empatica (c) E4 wristband) and assess the impact of a stress-focused debriefing on their physiological and psychological stress and satisfaction. Background: High-fidelity simulation is an innovative training method that improves satisfaction and learning in healthcare, including midwifery. However, students might experience pressure and this can result in stress during simulations. Design: A two-group randomized controlled. Methods: The study was conducted at a University College's High-Fidelity Perinatal Simulation Centre in Belgium. Participants included fifty-six second- and third-year midwifery students. The intervention group received a stress-focused debriefing in addition to a standard debriefing, while the control group received routine standard debriefing. Physiological stress was continuously monitored using the E4 wristband, which measures electrodermal activity, heart rate, blood pressure and temperature. Measurements were divided into time periods: pre-simulation (T-0), scenario-running (T-1), debriefing (T-2) and post-simulation (T-3). Psychological stress was assessed at T-0 and T-3 using the Short Stress State Questionnaire and satisfaction was evaluated the Satisfaction with Simulation Experience Scale at T-3. Results: The intervention group showed a significant reduction in psychological stress and higher satisfaction than the control group (p < 0.001). Electrodermal activity at T-2 and heart rate at T-3 were significantly lower in the intervention group than the control group (p < 0.05). Conclusions: A stress-focused debriefing effectively reduces midwifery students' psychological and physiological stress while enhancing satisfaction. Electrodermal activity and heart rate parameters offered valuable insights into the students' physiological responses during perinatal simulation.Scientific and Technological Research Council of Turkey (TUBITAK) [1059B192100834]This study was conducted as part of the SimStress Project (Stress Measurement during Simulation Training) and was funded by the Scientific and Technological Research Council of Turkey (TUBITAK) (Grant ID: 1059B192100834) in the framework of 2219-International Postdoctoral Research Fellowship Program

Gloss and Oscillatory Hardness Test Effects of Varnishes with Different Ratios of Marble Powder Additives on Wood Materials

Increasing global problems and stricter regulation of industrial waste management necessitate a more detailed examination of waste materials. In addition, because of problems such as surface cracking and discoloration of surface-treated materials during use, increasing varnish durability is a popular topic today. In this study, to increase the surface treatment performance, different proportions (2.5%, 5%) of waste marble powder were added into varnishes (water-based and polyurethane varnish) and their effect on surface treatment was evaluated in terms of gloss and oscillatory hardness test. The highest gloss and oscillatory hardness was found in specimens where the marble powder was at a 2.5% level. As the proportion of marble powder in the mixture increased, it had a matting effect. Oscillatory hardness was found to be higher in polyurethane varnish in the radial section. Among the wood species, beech wood exhibited the highest hardness value with polyurethane varnish. © 2025 Elsevier B.V., All rights reserved

The effects of different storey heights on structural behavior of RC buildings according to 1998 and 2018 Turkish earthquake codes: comparative study

Türkiye aktif bir fay hattı üzerinde yer almaktadır. Bu sebeple deprem, Türkiye için kaçınılmaz bir gerçektir. Sıklıkla büyük depremlerin yaşandığı ülkemizde, büyük ölçüde can ve mal kayıpları meydana gelmektedir. Bu kayıpların önlenmesi amacıyla deprem yönetmelikleri sürekli güncellenmektedir. Bu çalışmada, iki farklı deprem yönetmeliğinin kıyaslanması amaçlanarak, farklı kat yüksekliklerine sahip betonarme yapıların nümerik modelleri oluşturularak 1998 ve 2018 deprem yönetmeliklerine göre yapısal analizleri gerçekleştirilmiştir. Analizler sonucunda, doğal titreşim periyodu, maksimum yer değiştirmeler, göreli kat ötelenmeleri, taban kesme kuvvetleri ve burulma düzensizliği katsayıları karşılaştırılmıştır. Çalışmanın sonucunda, basit ve simetrik bir taşıyıcı sistem seçiminin, düzensizliklerin önüne geçebileceği ancak kat yüksekliğinin arttığı durumlarda taşıyıcı sistemin olumsuz olarak etkilendiği tespit edilmiştir.Turkey is located on active fault zone. For this reason, earthquakes are an inevitable reality for Turkey. In our country, where major earthquakes occur frequently, there is a great loss of life and property. In order to prevent these losses, earthquake regulations are continuously updated. In this study, with the aim of comparing two different earthquake codes, numerical models of reinforced concrete structures with different storey heights were created and structural analysis were carried out according to the 1998 and 2018 earthquake codes. As a result of the analysis, the period, maximum displacements, relative interstory drifts, base shear forces and torsional irregularity coefficients were compared. As a result of the study, it was determined that the selection of a simple and symmetrical structural system could prevent irregularities, but the structural system was negatively affected when the storey height increased