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Cognitive and motor dual-task performance in older adults with prediabetes and type 2 diabetes mellitus: A cross-sectional study
No full textType 2 diabetes mellitus (T2DM) and prediabetes (PreDM) are common among older adults and are associated with cognitive and physical impairments. Dual-task testing, which combines motor and cognitive tasks, reflects real-world functional ability. However, comparisons of dual-task performance between older adults with T2DM and PreDM are limited. This study aimed to compare cognitive and motor dual-task performance and related physical and cognitive parameters in older adults with T2DM and PreDM. This cross-sectional study included 46 older adults (23 T2DM and 23 PreDM), all aged >= 65 years. Dual-task performance was assessed using the timed up and go test under motor (TUG-Motor) and cognitive (TUG-Cog) conditions. Fatigue was measured by a Visual Analogue Scale; handgrip strength was measured with a dynamometer; physical performance was evaluated via the Short Physical Performance Battery (SPPB); and cognitive function was assessed with the Mini-Mental State Examination. Compared to the PreDM group, the T2DM group had significantly poorer dual-task cognitive performance (TUG-Cog) (P = .001)and higher fatigue (P = .004). The T2DM group also had lower Mini-Mental State Examination (P = .04) scores and lower SPPB scores (P = .02). There was no significant difference in TUG-Motor time (P = .129). In both groups, TUG-Motor time strongly correlated with SPPB (T2DM, r = -.720; PreDM, r = -.727) and TUG-Cog time moderately correlated with SPPB (T2DM, r = -.596; PreDM, r = -.517) (P < .01 for all). Dual-task performance is closely linked to physical function in older adults with T2DM and PreDM. Older adults with T2DM showed greater deficits in dual-task cognition, cognitive function, and physical performance than those with PreDM. Early interventions to improve dual-task ability may help preserve independence and reduce fall risk in this population
Compatibility of melamine formaldehyde- and polycarboxylate-based superplasticizers on slag/sintering ash-based geopolymer paste
No full textThe high viscosity of a geopolymer based on fresh slag/ash represents a notable drawback in terms of workability. This research delves into the potential advantages of incorporating a superplasticizer to address the low workability of geopolymers. Innovatively, geopolymer pastes were formulated using energy production system ash (EPA) and ground granulated blast furnace slag (GGBFS), alongside melamine formaldehyde and polycarboxylate-based superplasticizers (SPs). Furthermore, paste formulations incorporated maximized emission reduction of sintering (MEROS) ash (SA), a by-product of the steel industry. Flow table and marsh funnel time tests were conducted to assess the impact of 1 %, 2.5 %, and 5 % SPs and SA on fresh-state behavior of the geopolymer pastes. Comprehensive examinations of physical, mechanical, and morphological characteristics of the geopolymer pastes were undertaken under two conditions: without and with NaOH (at various NaOH concentrations). The findings indicate that, the presence of SPs has minimal impact on the workability of the pastes. However, when the NaOH is used instead of the Na2SiO3 at 10 %, inclusion of 1 % polycarboxylate-based (PCE), melamine formaldehyde-based (MF) SPs and SA results in a dramatic decrease in the marsh funnel time by 12, 8.5 and 5.3 times, respectively. While the inclusion of 1 % PCE and MF increases the 28-day compressive strength of the geopolymer paste by about 48 % and 4 %, respectively, the addition of 1 % SA causes a significant improvement in the 28-day compressive strength by about 87 % under NaOH-free condition. When 10 % NaOH is used, an increase in the SPs content from 0 % to 5 % leads to a reduction in compressive strength, while the use of 5 % SA leads to an increase in 7-, 28-, and 90-day compressive strength by approximately 33 %, 35 %, and 16 %, respectively. Microstructure analysis reveals that geopolymer gels such as calcium aluminum silicate hydrate and sodium aluminum silicate hydrate can contain sulfur derived from the admixtures. The use of SA not only improves mechanical properties but also promotes sustainable utilization of industrial by-products in construction materials
Teacher Practices and Student Understandings in 2D Drawings of 3D Shapes
No full textGeometry holds a pivotal position within the realm of mathematics, yet many students struggle to grasp its concepts, posing challenges for their teachers. In the Republic of Türkiye, the Ministry of National Education has recently recommended the adoption of constructivist approaches to teach geometry. To gauge the efficacy of this instructional approach in actual classrooms, we investigated the practices of Turkish middle school mathematics teachers and their students' experiences in constructing two-dimensional drawings of three-dimensional geometrical shapes during regular lessons. The study involved four teachers from two schools and 199 students aged 12 to 14 years. Multiple data sources, including lesson observations, student worksheets and interviews with teachers and students, were utilized to gain insights into student understandings and whether the pedagogical practices they encountered were associated with this. Based on these findings, we argue that teachers may require additional support for their classrooms to transition into student-centred environments to permit students to actively engage in enriching mathematical exercises, exercise agency, and have opportunities to utilize provided manipulatives and digital tools
Predictors of family burden in parents of children with intellectual disabilities and their children's sexual development characteristics
No full textIntroduction and aim. Although the existing literature includes both quantitative and qualitative studies that examine the sexual characteristics of children with intellectual disabilities and the challenges they face, these studies have not addressed the impact of these characteristics on the burden of the family. Our objective was to examine the predictors of sexual development of family burden among parents of children with intellectual disability in this cross-sectional study. Material and methods. We collected data from 815 parents with children aged 10–18 years with intellectual disabilities between May 2021 and March 2022. Data collection tools were ‘Descriptive Characteristics Form”, “Family Burden Rating Scale for families with Mentally Handicapped Children” and ‘Sexual Development Characteristics scale of Adolescents with Intellectual Disability”. A logistic regression analysis was performed. Results. The predictive model for the burden of the family explained 60% of the variance in this sample of parents (p <0.001). The sexual predictors with the strongest effect on the model were previous sexual development education (?=0.74; SE=0.16, p?0.001), followed by sexual harassment (?=-0.56, SE=0.26, p?0.001). Conclusion. Education on sexual development in children with intellectual disability can facilitate management of challenges in adolescence. © 2025 Elsevier B.V., All rights reserved
Some types of convergence in probabilistic g-metric spaces
No full textBu tez çalışmasında, olasılıksal G-metrik uzaylarda (O�����MU) çift diziler için lacunary istatistiksel yakınsama kavramı sunulmaktadır. Belirtilen uzaylarda, lacunary istatistiksel yakınsayan çift dizilerin temel özellikleri özetlenmiş ve lacunary yakınsama için gerekli (ancak yeterli olmayan) bir koşul verilmiştir. Ayrıca, bu yeni kavramın pratik uygulamasını göstermek amacıyla çeşitli örnekler sunulmuştur. O�����M uzaylarda çift diziler için, ℑ2 yakınsaklık, ℑ2-istatistiksel yakınsaklık ve ℑ2-istatistiksel Cauchy kavramları tanımlanmış ve bu kavramların temel özellikleri ile aralarındaki ilişkiler incelenmiştir.In this thesis, the concept of lacunary statistical convergence for double sequences in probabilistic G-metric spaces (PGMS) is presented. In these spaces, the fundamental properties of lacunary convergent double sequences are outlined, and a necessary (but not sufficient) condition for lacunary convergence is provided. Additionally, various examples are given to illustrate the practical application of this new concept. In probabilistic G-metric spaces, we define the notions of ℑ2-convergence, ℑ2-statistical convergence, and ℑ2 statistical Cauchy for double sequences, and investigate their fundamental properties and relationships
Investigation of the effects of laser surface modification on wear performance in AISI D2 tool steel
No full textBu çalışmada, AISI D2 soğuk iş takım çeliği üzerindeki farklı lazer tekstür desenlerinin tribolojik davranışları, ball-on-disk aşınma test düzeneğinde kuru kayma ve MoS2 katı yağlayıcı koşulları altında, farklı yükler (2N ve 4N) ve kayma süreleri (15 ve 30 dakika) kullanılarak gerçekleştirilmiştir. Deneysel sonuçlar, lazerle yüzey modifikasyonunun tüm tekstür desenli yüzeylerde aşınma direncini ve sürtünme özelliklerini önemli ölçüde iyileştirdiğini göstermiştir. Kuru kayma koşullarında 4N yük ve 30 dakika kayma süresi altında en yüksek hacim kaybı (0,894x10-3 mm3) ve sürtünme katsayısı (?=0,90) değerleri lazersiz yüzeyde elde edilmiştir. Buna karşın, büyük daire deseni tüm koşullarda en üstün performansı göstermiş, 2N yük ve 15 dakika kayma süresi altında hacim kaybını lazersiz yüzeye kıyasla %19 (0,801x10-3 mm3'ten 0,647x10-3 mm3'e) ve sürtünme katsayısını %24 (0,90 ?'den 0,68 ?'ye) düşürerek belirgin iyileşme sağlamıştır. MoS2 katı yağlayıcı kullanımı ise performansı daha da artırmış, büyük daire desenli yüzeyde en etkili sonuçlar elde edilmiştir. Büyük daire deseni ile MoS2 yağlayıcının birlikte kullanımı, 2N yük ve 15 dakika kayma süresi altında tüm test koşulları içerisinde en düşük hacim kaybı (0,106x10-3 mm3) ve minimum sürtünme katsayısı (?=0,109) değerleriyle mükemmel performans sergilemiştir. Kuru koşullara kıyasla, hacim kaybında %84 ve sürtünme katsayısında %82-84 oranında iyileşme sağlanmıştır. SEM, EDS ve 3D profilometre analizleri, tekstürlü yüzeylerde çukurların aşınma kalıntılarını hapsettiğini ve MoS2 varlığında aşınma derinliğinin %85-90 (4 ?m'den 0,4-0,6 ?m'ye) azaldığını göstermiştir. Artan yük ve kayma süresi tüm yüzeylerde hacim kaybını artırsa da, lazer tekstürlü yüzeyler yüksek yük koşullarında bile üstün direnç göstermiştir. Sonuç olarak, optimum lazer tekstür desenlerinin ve MoS2 yağlayıcının birlikte kullanımı, AISI D2 takım çeliğinin tribolojik performansını önemli ölçüde iyileştirmekte ve endüstriyel uygulamalarda takım ömrünün uzatılması için umut verici çözümler sunmaktadır.This study investigates the tribological behavior of different laser texture patterns on AISI D2 cold work tool steel using a ball-on-disk wear test rig under both dry sliding and MoS2 solid lubricant conditions, at various loads (2N and 4N) and sliding durations (15 and 30 minutes). Experimental results demonstrated that laser surface modification significantly improved wear resistance and friction properties across all textured surfaces. Under dry sliding conditions at 4N load and 30 minutes sliding duration, the highest volume loss (0.894x10-3 mm3) and friction coefficient (?=0.90) values were obtained on the untextured surface. In contrast, the large circle pattern exhibited superior performance under all conditions, reducing volume loss by 19% (from 0.801x10-3 mm3 to 0.647x10-3 mm3) and friction coefficient by 24% (from ?=0.90 to ?=0.68) compared to the untextured surface under 2N load and 15 minutes sliding duration. The application of MoS2 solid lubricant further enhanced performance, with the most effective results achieved on the large circle patterned surface. The combination of large circle pattern and MoS2 lubricant exhibited excellent performance with the lowest volume loss (0.106x10-3 mm3) and minimum friction coefficient (?=0.109) values among all test conditions under 2N load and 15 minutes sliding duration. Compared to dry conditions, improvements of 84% in volume loss and 82-84% in friction coefficient were achieved. SEM, EDS, and 3D profilometer analyses revealed that the dimples in textured surfaces effectively trapped wear debris and wear depth decreased by 85-90% (from 4 ?m to 0.4-0.6 ?m) in the presence of MoS2. Although increased load and sliding duration raised volume loss across all surfaces, laser-textured surfaces demonstrated superior resistance even under high load conditions. In conclusion, the combined use of optimum laser texture patterns and MoS? lubricant significantly improves the tribological performance of AISI D2 tool steel, offering promising solutions for extending tool life in industrial applications
The Effect of Climate Change on Forest Fires: A Study on Forest Engineers in Terms of Psychosocial Risks
No full textBu çalışma açık havada çalışma, orman yangınlarına doğrudan müdahale eden ve yangınla mücadele ekibinin sorumluluğunu alan olan Orman Mühendislerinin tükenmişlik ve iklim değişikliği anksiyetesini ölçmek ve önlemler alınmasına dikkat çekmek amacıyla yürütülmüştür. Literatür incelenmiş, ölçülmek istenen yapı belirlenerek ölçek seçimi yapılmıştır. Elde edilen ölçekler ile hedeflenen bilgilere ulaşılıp ulaşılamayacağı konusunda tartışma gerçekleştirilmiştir. Araştırma kapsamında 101 Orman Mühendisinden veri elde edilmiş, elde edilen verilerin istatistiği için IBM SPSS 25.0 programı kullanılmıştır. Kolmogorov-Smirnov testi uygulanarak normallik dağılımındaki sapma sebebiyle Outlier testi uygulanarak 4 veri çalışmadan çıkarılarak Tükenmişlik Ölçeği için 0,077 ve İklim Değişikliği Anksiyetesi Ölçeği için 0,177 olarak elde edilmiş normal dağıldı varsayılmıştır. Ölçeklerin geçerlilik ve güvenirlik çalışmaları yapılmış olmasına karşın açıklayıcı ve doğrulayıcı faktör analizi yinelenmiş Kaiser-Mayer-Olkin değeri 0,866 olarak elde edilmiş ve Barlett küresellik testi de anlamlı olarak görülmüştür. İki ölçeğin bir arada kullanılması sebebi ile Cronbach Alpha katsayıları yeniden hesaplanarak 0,947 bulunmuştur. Ölçeklerin tek faktörlü kullanılması sebebi ile alt faktörlerine test yinelenmemiştir. Orman Mühendislerinin; yaş, medeni durum, çocuk sahibi olma, meslek yılı, orman yangınlarına maruz kalma ve mevsimin stres düzeylerine etkileri t-testi ve ANOVA yöntemleri kullanılarak irdelenmiştir. Elde edilen verilerin ışığında Orman Mühendislerinin yangında kayıp yaşamalarının tükenmişliklerini arttırdığı, yaz mevsimlerinde kaygı düzeylerinin daha yüksek olduğu sonucuna varılmış, yapılandırılmamış yüz yüze derinlemesine görüşme tekniği ile Orman Mühendislerinin yaz dönemlerinde ailesel problemlerinin arttığı iş streslerinin eve yansıdığı öğrenilmiş, çalıştıkları kurumlarda destek alabilecekleri ruh sağlığı profesyonellerinin olması ve periyodik olarak psikososyal görüşmelerin yapılması çalışanların geleceği açısından önem arz ettiği sonucuna varılmıştır.This study was conducted to measure the burnout and climate change anxiety of Forest Engineers, who are outdoor workers and take direct part in forest fire interventions, taking on the responsibility of the team that intervenes beyond their duties, and to highlight the importance of taking preventive measures. A literature review was conducted, and the structure to be measured was determined, followed by scale selection. A discussion was carried out regarding whether the targeted information could be obtained with the selected scales. Data were collected from 101 Forest Engineers, and IBM SPSS 25.0 software was used for statistical analysis of the data. The Kolmogorov-Smirnov test was applied, and due to the deviation in normality distribution, the Outlier test was performed, and 4 data points were excluded from the study. The Tiredness Scale was found to have a normal distribution with a value of 0.077, and the Climate Change Anxiety Scale had a normal distribution with a value of 0,177. Although the validity and reliability of the scales were tested, an exploratory and confirmatory factor analysis was conducted, yielding a Kaiser-Meyer-Olkin value of 0.866, and the Bartlett's sphericity test was found to be significant. Since both scales were used together, Cronbach's Alpha coefficients were recalculated, resulting in a value of 0.947. Since the scales were used as single factors, the sub-factors were not tested. The effects of the Forest Engineers' age, marital status, having children, years of profession, experience in forest fires, and seasonal stress levels were examined using t-test and ANOVA methods. Based on the obtained data, it was concluded that Forest Engineers' burnout increased when they experienced loss during a fire, and their anxiety levels were higher in the summer months. Furthermore, through unstructured face-to-face in-depth interviews, it was learned that during the summer period, Forest Engineers faced increased family problems, and their work stress reflected on their home lives. The presence of mental health professionals in their working institutions and periodic psychosocial consultations were concluded to be crucial for the future of the employees
Exploring effect of CACC vehicle types on freeway traffic flow: Case study on a Bosphorus Strait
No full text26th EURO Working Group on Transportation, EWGT 2024 -- Lund -- 208991This study investigated the impact of integrating CACC-equipped buses into a mixed-Autonomy environment within a single-direction bus rapid transit corridor. Utilizing a SUMO microsimulation of Istanbul's Metrobus System, specifically the segment where BRT vehicles merge with regular traffic on the D-100 freeway to cross the 15 Temmuz Bridge in the Europe to Asia direction, we examined the effects of varying market penetration rates (MPRs) of CACC vehicles on throughput, total system travel time, emissions, and average speed on the bridge. Results revealed that increasing the MPR of CACC vehicles led to improved throughput, particularly when BRT buses were also CACC-equipped. This improvement came with a slight increase in total system travel time, but overall traffic efficiency was enhanced. Notably, CACC-equipped BRT buses caused minor disruptions in a fully human-driven traffic stream, highlighting the importance of consistent CACC implementation across vehicle types. While emissions generally increased with higher MPRs of CACC vehicles, the relative increase between scenarios with and without CACC-equipped buses remained minimal, suggesting a potential for environmental benefits alongside improved efficiency. © 2025 Elsevier B.V., All rights reserved
Enhancing ERA5 precipitation with improved predictor selection for regional climate change assessment
No full textAccurate regional precipitation projections are critical for effective climate impact assessment and adaptation planning. This study presents a novel methodology for enhancing ERA5 reanalysis precipitation data through optimized predictor selection and statistical downscaling using the Multivariate Adaptive Regression Splines (MARS) algorithm. Four distinct predictor selection scenarios: a full 26-variable model, a reduced 14-variable model based on correlation and physical relevance, a compact 6-variable model emphasizing simplicity, and a station-specific model derived from All Possible Regression (APR), were used along with the MARS algorithm. Predictor variables were selected through traditional correlation analyses (Pearson and Spearman), the APR-based approach, and performance-based evaluation using MARS. The resulting downscaled models were evaluated using different performance metrics, including Kling-Gupta Efficiency (KGE), Nash-Sutcliffe Efficiency (NSE), normalized Root Mean Square Error (nRMSE), and the coefficient of determination (R-2). The Western Black Sea Basin in T & uuml;rkiye, with monthly precipitation data from 32 meteorological stations (1979-2023), was selected as an application to apply the newly proposed dual-stage approach. Results demonstrated that all MARS-enhanced models significantly outperformed the raw ERA5 data, particularly in inland regions where ERA5 performance was initially poor. The APR-based model emerged as the top performer across most stations, while the 6-variable model provided a strong balance between accuracy and simplicity. While the nRMSE initially reached around 77% at some stations, it was significantly reduced to 24.6%, 29%, 26.4%, and 25.1% under the 26-variable, 14-variable, 6-variable, and APR scenarios. The KGE nearly doubled, reaching approximately 0.7-0.9 across all scenarios, confirming the substantial improvement applied to the ERA5 precipitation data. This approach, integrating correlation-based and predictive performance-driven variable selection, proved effective in refining regional precipitation projections. The methodology can be adapted to other regions or climate variables, offering a replicable framework for improving the usability of reanalysis data in hydrological and climate impact studies
Visual and Colorimetry Assessments of Synthetic Resin Impregnated ? -Cellulose Decor Paper Laminated Particleboard Surfaces: A Comparative Study
No full textBu çalışma, beyaz dekor kağıdı ile kaplanmış ve ?-selüloz bazlı melamin reçine ile emprenye edilmiş yonga levha yüzeylerinin beş farklı yüzey işlem maddesi ile muamele edildikten sonra görsel ve enstrümantal olarak incelenmesini amaçlamaktadır. Üç farklı tür (-A, -B, -C) ve her biri için üç farklı gramajda kaplanmış numuneler TS EN 14323 standardına göre değerlendirilmiş, renk ve doku değişiklikleri karşılaştırılmıştır. Veriler istatistiksel olarak analiz edilerek ANOVA ve Duncan testi kullanılmıştır. En düşük parlaklık değeri (L*: 92.79) 110 g/m² gramajlı B tipi dekor kağıdı ile kaplanmış ve su (Wa) ile aseton (Ac) ile işlenmiş numunelerde tespit edilmiştir. a* renk koordinatı değerleri ihmal edilebilir düzeyde (a*:This study aims to visually and instrumentally examine the surfaces of particleboards laminated with white decor paper impregnated with ?-cellulose-based melamine resin after treatment with five different surface processing agents. Samples of three different types (-A, -B, -C), each with three different grammages, were evaluated according to the TS EN 14323 standard, and color and texture changes were compared. The data were statistically analyzed using ANOVA and the Duncan test. The lowest brightness value (L*: 92.79) was found in samples laminated with 110 g/m² grammage B-type decor paper and treated with water (Wa) and acetone (Ac). The a* color coordinate values were found to be negligible (a*