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Investigation of fatigue behaviors of Al6061 matrix marble powder reinforced composite
No full textIn the present study, we focused on the usability of waste marble powder (MP) as a reinforcement in Metal Matrix Composites (MMCs) and its compatibility with SiC and Al2O3. Al6061 alloy, which is frequently used in the aerospace industry, was chosen as the matrix. Composites were fabricated using reinforcements with 22-59 mu m powder size at different reinforcement-volume ratios. Two-stage stir casting method was used in the production of composites. The microstructures of the composites were visualized by scanning electron microscopy to determine the presence of reinforcements. The hardness of the composites was determined by the Brinell hardness measurement method. For the fatigue strength of the composites, the number of cycles was measured for 9 different stress values using a rotational bending fatigue device until the specimens ruptured. The addition of 5% marble powder to the Al6061 alloy increased the hardness by 20.69%, reaching 70 HBN. In binary hybrid composites, the highest hardness value was measured at 95 HBN in the sample reinforced with 3% SiC and 5% MP. For ternary hybrid composites, the hardness value of the composite containing 3% SiC, 3% Al2O3, and 5% MP was found to be 109 HBN. In the rotational bending fatigue test, the Al6061 alloy fractured after 820,783 cycles at a stress value of 100 MPa. However, with the addition of 5% MP to the matrix, the number of cycles approximately doubled to 1,643,127. Hardness measurement results showed that the marble powder can be almost as effective as SiC and Al2O3 in increasing the hardness of the composite. Marble powder reinforcement also increased the fatigue strength of the composites like other reinforcements
The effect of two different video demonstrations on pain and anxiety in children undergoing adenotonsillectomy: A randomized controlled trial
No full textAim: The study was conducted to determine the effect of two different video demonstrations on pain and anxiety in children undergoing adenotonsillectomy. Methods: This randomized controlled trial (NCT06339866) was conducted by randomly assigning children aged 6-12 years who underwent adenotonsillectomy to three groups (animation group = 34, cartoon group = 32 and control group = 32). Data were collected using Sociodemographic Questionnaire, Wong-Baker Faces Pain Rating Scale, Child Anxiety Scale-Conditioning (CAS-C). Results: The pain score of the children in the control group was found to be significantly higher than that of the other groups (p < 0.05). Furthermore, the pain score of the children in the cartoon group was found to be significantly higher than that of the children in the educational animation group (p < 0.05). In all of the parent and nurse assessments, the mean scores of the children in the education group were found to be lower after surgery compared to the preoperative period (p < 0.001). A negative correlation was observed between Wong- Baker Faces Expressions Pain Rating Scale scores and change in CAS-C scores (p < 0.05). The changes in CAS-C scores accounted for 26.1 % of the total variance in pain scores according to the children's assessment, 19.0 % according to the parents' assessment, and 42.6 % according to the nurses' assessment. The intraclass correlation analysis was conducted to assess the agreement between the mean scores of children, parents, and nurses on the Wong-Baker Faces Expressions Pain Rating Scale and the CAS-C. The results demonstrated excellent agreement (p < 0.001). Conclusion: The use of educational animation and cartoons in the preoperative period has a significant effect on reducing postoperative anxiety and pain levels in children. The use of educational animation was found to be the most effective method. In future studies, it is recommended that more impressive videos and presentations with technological developments be used comparatively both in children undergoing adenotonsillectomy and in children undergoing different surgical procedures
The relationship between cyber wellness and psychological resilience in children: a cross-sectional study
No full textAim: This study aimed to examine the relationship between cyber health and psychological resilience among children. Methods: A cross-sectional study design was employed, with data being collected from a sample of 420 middle school students. The Student Cyber Health Scale (SCHS) and the Child and Adolescent Psychological Resilience Scale (CAPRS) were utilized as data collection instruments. Results: The study revealed that 87.1% of the children accessed the internet through their phones, with an average usage time of 2.75 ± 2.16 hours. The study found a positive correlation between psychological resilience scores and various cyber health sub-dimensions. Specifically, a series of significant positive correlations were identified, with psychological resilience scores demonstrating positive associations with various aspects of cyber health, including awareness of internet addiction (r=0.385, p<0.001), online courtesy (r=0.414, p<0.001), online privacy (r=0.384, p<0.001), online safety (r=0.493), cyberbullying awareness (r=0.534, p<0.001), and online inappropriate content awareness (r=0.450, p<0.001). An increase of one unit in psychological resilience level was associated with a corresponding increase of 0.534 in cyberbullying awareness score, 0.414 in online kindness awareness score, 0.386 in online privacy awareness score, 0.450 in online inappropriate content awareness score, and 0.443 in online safety awareness score. Conclusion: It is imperative to educate children from an early age about the risks and responsibilities associated with online interactions. It is imperative to inculcate a sense of awareness regarding cyber health from the onset of the academic year. To this end, the development and implementation of psychoeducation programs and group training on topics such as media literacy and online privacy protection is recommended. © 2025 Elsevier B.V., All rights reserved
'What Was Going to Happen to Us?' Understanding the Need of Family Members After A First Episode Psychosis: A Qualitative Study From Turkey
No full textIntroductionBeing diagnosed with first episode psychosis (FEP) can be a crisis for both individuals and family members in the early years. In this process, family life and interpersonal relationships may deteriorate, and stigmatisation may be observed. Learning about the feelings, experiences, and needs of families after the diagnosis of FEP will help in coping with the disease and in predicting its prognosis.AimThis study aimed to determine the experiences and needs of family members after a diagnosis of FEP.MethodsThis qualitative study was conducted with first-degree relatives of individuals diagnosed with FEP who the psychiatry outpatient clinic of a hospital in Turkey followed up. The sample of the study consisted of 17 participants. A semi-structured interview form was used to collect the data. N-Vivo12 program with thematic analysis method was used for data analysis and COREQ checklist was used for reporting.ResultsIt was found that 64.7% of the participants were in the role of mother, 64.7% were primary school/middle school graduates, and 29.4% had quit their jobs due to their caregiving role. As a result of the interviews, 4 main themes and 13 sub-themes were identified. The main themes are as follows: not knowing/not realising, mixed feelings, changing lives and need for help.DiscussionInterventions are needed to increase community mental health literacy and reduce stigmatising attitudes. Mental health professionals should be aware that cultural beliefs and spiritual values are effective in community mental health and should raise awareness of evidence-based treatments in the community.Implications for PracticeThese findings will raise awareness for mental health professionals that they should not overlook the family while providing health services to individuals diagnosed with FEP. In addition, psychiatric nurses can use the findings to create training and support programmes for families
Large-scale earth observation and monitoring of riparian zone land-cover changes in Türkiye
No full textRiparian zone ecosystems provide various ecological and societal benefits and play a vital role in preserving biodiversity in fragmented landscapes. These ecosystems land use changes serve as reliable indicators of large-scale ecological system changes. The aim of this study is to monitoring the changes in land use and land cover in riparian zones and how this affects ecosystem services at the T & uuml;rkiye scale. Many open source platforms that integrate remote sensing and geographic information systems have been frequently used in regional and national scale land monitoring studies in recent years. For this study, Collect Earth, an open source program authorized by the Food and Agriculture Organization, was chosen. Collect Earth is a tool that enables data collection for land monitoring via Google Earth technologies. Analysis indicates that only 2.7% of T & uuml;rkiye's zones of riparian which is experienced land use changes from 2000 to 2023. While there was a decline in forest land, grassland, and cropland, there was an increase in wetland, settlement, and other land types within T & uuml;rkiye's riparian zones. Logging, crop cultivation, and road construction are the main drivers of land cover change in these areas. Approximately half of the increase in riparian zones was attributed to cropland expansion. It is crucial to emphasize the importance of integrating the carnage statistics of land use change statistics with areas of gain loss to assess the land capacity of land to provide services of ecosystem. The Collect Earth methodology can aid in evaluating environmental policy objectives and assisting in the riparian zones of regional management and planning.Ondokuz Mayimath;s UniversityNot applicabl
Monitoring Land Cover/Use Conversions in Türkiye Wetlands Using Collect Earth
No full textWetlands provide biodiversity conservation, carbon sequestration, recreation services, and contribute to the health and resilience of the overall ecosystem. It is of great importance to protect wetlands to ensure that these benefits are sustainable and to mitigate the effects of climate change. Overall, monitoring environmental changes in wetlands plays a vital role in understanding, managing, and safeguarding wetland environments and resources. Accessible platforms providing diverse RS&GIS integrated methodological approaches to continental/national land-cover changes provide important information about the direction and causes of land-cover changes as well as their possible effects on ecosystems, biodiversity, and human societies. Open-source platforms and data are frequently used to collect and evaluate data quickly and efficiently. This has successfully implemented land monitoring and provided fresh opportunities for Earth observation applications. According to the 2020 official data, 93 wetlands in T & uuml;rkiye are recognized as being of national/international significance (and 14 of these wetlands are protected under the Ramsar Convention) and were selected as the study area. The focus of our evaluation is on the LULC classes and conversions of the T & uuml;rkiye Wetland, as well as the 22-year (2000-2022) LULC vegetation gain and loss land determination. This article examines T & uuml;rkiye Wetland environment monitoring using Collect Earth (CE), a free open-source and user-friendly software tool developed by the Food and Agriculture Organization of the United Nations (FAO), a land monitoring platform powered by Google Earth Engine (GEE). The primary objectives of this study are threefold: (1) to ascertain Wetland land cover/use classes; (2) to identify land cover/use conversion and direction in wetland areas with different statuses; and (3) to delve into potential factors driving shifts in wetland land cover/use, particularly the loss-gain areas. The anticipated outcomes of the study, an enhanced comprehension of factors influencing regional wetlands in the context of environmental conservation, water management, climate change mitigation, and economic benefits, will empower planners and policymakers to formulate appropriate strategies for the long-term conservation of these vital ecosystems. Furthermore, this study example demonstrates that Collect Earth is a comprehensive and user-friendly tool for land monitoring, can be used to rapidly and sustainably build capacity for land monitoring, and to substantively improve our collective understanding of Wetland land use and land cover.Bartin University, Graduate Education Institute, Forest Engineering Department Master's ProgramThis article was prepared by Bartin University, Graduate Education Institute, Forest Engineering Department Master's Program. It was prepared by using the data in the Master's Thesis titled Monitoring of land use changes on the wetlands within scope land degradation neutrality in Turkey completed in 2022 by Berat Umut Baysal under the consultancy of Dr. Ayhan Atesoglu
Optimizing influence propagation in directed networks: Novel formulations
No full textThis paper aims to identify influential nodes in complex networks in a short period of time by proposing novel formulations. Traditional centrality metrics have ranked nodes based on individual centrality values, which fall short in identifying several influential nodes simultaneously. Recent literature has introduced an optimization model as a solution to this limitation; however, this model has some shortcomings such as long solution return time and high memory usage. In this paper, two novel formulations are presented as alternatives to this optimization model, with a primary goal of reducing the time needed to obtain solutions. Computational tests have shown that whereas the existing model is unable to return a solution within a 5hour time frame for a small network with approximately 5,000 nodes, the proposed formulations can identify the most influential nodes within minutes, even for large networks with more than 100,000 nodes. The superiority of the proposed models actually lies in their significant reduction in the number of constraints and variables compared to the existing model. Additionally, this paper introduces a novel alternative formulation that addresses the overlapping effect observed in the previous formulations. Computational tests have shown that this model surpasses its predecessors in accelerating the spread of influence throughout the network without causing additional computational burden, thereby setting a better benchmark for future studies in this field
Effects of Velocity Pulse-Like Ground Motions on the Seismic Failure Behavior of Masonry Minarets
No full textThis research is motivated by post-earthquake observations of significant structural damage to minarets during the 2023 Kahramanmara & scedil; earthquakes. It is thought that the near-fault velocity pulse-like ground motions played a crucial role in this phenomenon. Although the seismic performance of minarets has been extensively studied, including a large body of literature on numerical and experimental analyses, no attention has been paid to the seismic damage assessment of minarets subjected to strong velocity pulse-like ground motions. The present study aims to investigate the effects of near-fault strong velocity pulse-like ground motions with different velocities on the seismic failure behavior of masonry minarets. A 33-meter-high stone masonry minaret was selected for this purpose. Nonlinear behavior of masonry unit is modeled using Concrete Damage Plasticity (CDP). For the nonlinear analysis, three near-fault strong velocity pulse-like ground motions recorded during February 6, 2023, Kahramanmara & scedil; earthquake (M7.7) and one non-pulse-like ground motion were selected. Displacements, strains, stresses and damage patterns in masonry minarets subjected to near-fault velocity pulse-like and non-pulse-like ground motions were obtained and thoroughly evaluated across different ground velocities. The velocity, the number of pulses and the pulse duration of velocity-pulse-like ground motions have a significant influence on the structural damage behavior of minarets. The results provide a detailed understanding of how minarets respond to different velocity pulse-like ground motion scenarios, offering valuable insights for the design, rehabilitation, and retrofitting of both new and existing minarets
When teacher leadership backfires: Exploring the unintended consequences of teacher leadership
No full textThis study explores the unintended consequences of teacher leadership within the centralised and hierarchical education system of T & uuml;rkiye. Utilising a phenomenological approach, data were gathered through semi-structured interviews with 15 teachers, and content analysis was employed to analyse the data. Our findings reveal that teacher leadership practices unintentionally lead to stress, burnout, isolation, and role ambiguity at the individual level; peer jealousy and rivalry, along with challenges in promoting collaboration at the group level; create operational fragmentation and hierarchical tensions and power conflicts at the organisational level; and result in reduced time for student support and diminished instructional quality at the student level. This study adds nuance to the global school leadership literature by challenging the prevailing positive narrative surrounding teacher leadership and exposing its often-overlooked unintended consequences. We discuss implications for policy and practice
Application of Steel Pipe Culverts on Forest Roads (Yalıköy Forest Management Di-rectorate Example)
No full textOrman yollarının uzun süreli hizmet verebilmesi için drenaj yapılarının eksiksiz yapılması, suyun yol yüzeyinden ve çevresinden uzaklaştırılması gerekmektedir. Drenaj yapılarının planlanması, seçimi, konumlandırılması ve inşa edilmesi bu açıdan çok önemlidir. Bu çalışma, İstanbul Çatalca Orman İşletme Müdürlüğü'ne bağlı Yalıköy Orman İşletme Şefliği alanları içerisinde yer alan bir orman yolu üzerinde yapılmıştır. Bu yol üzerinde drenaj için çelik boru menfezler yapılmış ve bu menfezlerin teknik özellikleri, planlanması, yapımı ve konumlandırılması gibi tüm konular detaylı bir şekilde incelenmiştir. Çalışmada üç adet 80 cm, bir adet 150 cm, bir adet 160 cm ve bir adet 170 cm çapında 6 adet çelik boru menfez kullanılmıştır. Menfezlerin uzunlukları 7 ile 15 metre arasında değişiklik göstermiştir. Güzergah boyunca toplam 72 m menfez kullanılmış olup, bu menfezlerin toplam maliyeti 13.04,.00 USD olarak belirlenmiştir. Bu menfezlerin üç adedi dere geçişlerinde ve diğer üç adedi ise kenar hendeklerindeki suyun yolun karşısına geçirmekte kullanılmıştır. Talbot yöntemi ile menfezlerin hesaplanan kesit alanlarının menfez havzası için yeterli olduğu belirlenmiştir. Menfezler için gerekli kazı alanı boyutları, dolgu malzemesi miktarı ve baş duvar için gerekli olan taş malzeme gibi tüm teknik detaylar incelenmiştir. Çelik boru menfezlerin orman yolunda kullanılmasının diğer drenaj yapılarına göre sağladığı avantajlar ve dezavantajlar irdelenmiştir.In order for forest roads to provide long-term service, drainage structures must be properly designed and constructed to effectively remove water from the road surface and its surroundings. The planning, selection, positioning, and construction of these drainage structures are therefore of critical importance. This study was conducted on a forest road within the Yalıköy Forest Management Directorate under the Istanbul Forest Regional Directorate. For drainage purposes, steel pipe culverts were installed along this road and all aspects—including technical specifications, planning, construction, and positioning—were examined in detail. Six steel pipe culverts were used: three with a diameter of 80 cm, and one each with diameters of 150 cm, 160 cm, and 170 cm. The lengths of the culverts ranged from 7 to 15 meters, with a total of 72 meters of culvert installed along the road. The total cost of these culverts was calculated as $13,045.00 USD. Three culverts were used for stream crossings, while the other three served to convey water from roadside ditches across the road. The cross-sectional areas of the culverts, calculated using the Talbot method, were found to be adequate for the drainage basins. Technical details such as the dimensions of the required excavation areas, the amount of backfill material, and the stone material needed for headwalls were thoroughly analyzed. Additionally, the advantages and disadvantages of using steel pipe culverts on forest roads, compared to other types of drainage structures, were evaluated