Sakarya University of Applied Sciences AXSIS
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Recovery of gold from electronic waste by the synthesis of Pinus Brutia tannin polymer
No full textElectrical and electronic waste (e-waste) is one of the most common waste problems today and contains many recyclable materials such as gold and palladium. In this study, an adsorption material was prepared by reacting tannin from Pinus Brutia bark with formaldehyde to recover gold from e-waste. The produced Pinus Brutia tannin (PBTR) polymer was characterized using TGA, BET, and FTIR. The adsorption efficiency was investigated using solutions containing gold ions with different pH values, adsorbent masses, initial concentrations, times, and temperatures. The results of these experiments were used to perform adsorption isotherm, kinetics, and thermodynamics calculations. The pseudo-second-order kinetic equation and the Langmuir isothermal equation were found to fit the experimental data best. The Au(III) ion saturation capacity of the PBTR particle monolayer was calculated to be 1771.73 mg/g at 328 K using the Langmuir isotherm. XRD and XPS analyses showed that most of the Au(III) ions were reduced to metallic gold after adsorption on the surface of the PBTR particles. Observations show that the adsorbent effectively removes Au(III) from the leaching solution generated by e-waste. © 2024 Elsevier B.V
Detecting the Limitations of Performance: Performance Art as a Neo-Shamanistic Ritual; [Performansın Köklerine İnmek/Sınırlarını Belirlemek: Neo-Şamanist Bir Ritüel Olarak Performans Sanatı]
No full textSayısız performans sanatı örneği 1960’lı yıllardan günümüze, bu sanatı yeni ifade formlarından biri haline getirse de eyleme dayalı, ancak sahne sanatı olmayan performans sanatının ne olduğu, kökeni ve nasıl işlediğini akademik olarak net biçimde tanımlamak güçtür. Çünkü başta ritüel çalışmaları ve tiyatro kuramları gibi çeşitli performans teorileri, performans sanatını antik ritüellere bağlayarak tanımlamış, bir görsel sanat türü olarak performansın sınırlarını belirlemek zorlaşmıştır. Öte yandan 20 yüzyılda insanoğlunun kaybettiği doğayla yeniden bağ kurma isteği, neo-şamanist birer ritüel olarak uygulanan performansları ortaya çıkarmıştır. Modern seküler dünyada çağdaş sanat üretimi olarak şekillenen performans sanatının ritüel köklerinden kopup kopmadığını araştırmak, özellikle şamanik bir ritüel gibi uygulanan performans sanatı örneklerine odaklanarak mümkündür. Performans sanatı üzerine analitik eleştirel bir yaklaşım geliştirmeye çalışılan makale, onun bir çatı kavram olan “çağdaş sanat” içindeki yerini saptayabilmek için ritüel köklerini araştırmakta, tiyatro ile bağlarını sorgulamakta, Wagner’in “bütünsel sanat eseri” önerisini tartışarak avangart hareketlerin performans sanatına katkılarını ortaya koymaktadır. Makalede, yöntemin-formun, içeriği-anlatıyı belirlediği bir tür olarak performans sanatının kategorik tanımı yapılmaktadır. Bu doğrultuda Şamanizm’i bilen ve kendini neo-şaman olarak gören, pagan dinleri araştırarak beslenen, antik inanç ritüelleri ve tekniklerinden yararlandığını tespit ettiğimiz sanatçıların üretim dilleri, performans örnekleri üzerinden incelenmektedir. Böylece performans sanatının yeni çağ inançların dirilmesindeki payı da ortaya konmaktadı
Parametric Investigation of Corner Effect on Soil Nailed Walls and Prediction Using Machine Learning Methods
No full textThe performance of soil nailed walls is evaluated based on lateral displacements, especially in high walls. In this study, the displacement behavior of nailed walls, which are frequently preferred in retaining wall systems in hard clayey soils, was examined by taking into account the corner effect. The nailed wall model was created using Plaxis 2D v.23, and the performance of the model was verified with the results of inclinometer measurements taken on-site. To assess the influence of excavation pit dimensions on the corner effect, 25 three-dimensional and 25 plane–strain slice models were created using Plaxis 3D v.23, and the effect of excavation pit dimensions on the plane–strain ratio (PSR) was determined. Then, analysis studies were carried out by creating 336 3D and 336 plane–strain slice models with variable parameters, such as slope angle (β), wall angle (α), nail length (L/H), excavation depth (H), and distance from the corner (xH). Its effects on PSR were determined. The interactions of the parameters with each other and PSR estimation were evaluated using machine learning (ML) methods: artificial neural networks (ANN), classifical and regression tree (CART), support vector regression (SVR), extreme gradient boosting (XGBoost). The proposed ML prediction methods and PSR results were compared with performance metrics and reliable results were obtained. © 2024 by the authors
A closely spaced dual band polarization insensitive FSS for 5G applications
No full textThis study presents a novel single layer Frequency Selective Surface (FSS) for fifth generation (5G) applications with a polarization independent closely spaced dual band response. The proposed design consists of four split ring apertures etched on a square patch printed on a RT5880 dielectric substrate. The FSS has two stop-bands at 24.78 GHz and 28 GHz center frequencies with attenuations around 55 dB. The S21<−10 dB bandwidths (BW) of these bands are 14.48 % and 9.25 %, respectively and these closely spaced bands succeed 1.13 frequency ratio. It shows a stable frequency response for both TE and TM polarizations. Furthermore, the FSS represents a single layered and quite thin (thickness 0.042λl) structure with its unit cell size (0.70λl × 0.70λl, where λl is the free-space wavelength at lower frequency). The novelty of the presented FSS is not only achieving a small closely spaced band ratio in the mmWave band and exhibiting polarization insensitivity but also providing these features with a simple geometry and, uncomplicated single layer structure. The simulation results were confirmed by well accordant measurement results. All these results make the presented FSS a good candidate for 5G electromagnetic interference (EMI) shielding applications. © 2024 Elsevier Gmb
Futbol Antrenör Eğitim Programlarının Etkililiğine Yönelik Antrenör Deneyimlerinin İncelenmesi
No full textBu çalışmada, futbol antrenör eğitim programlarının etkililiğine ilişkin antrenör deneyimlerinin incelenmesi amaçlanmıştır. Nitel araştırma yöntemlerinden fenomenoloji deseninin kullanıldığı araştırmada amaçlı örnekleme yöntemlerinden ölçüt örnekleme yöntemi kullanılmıştır. Araştırmaya 2022 yılında Antalya’da Türkiye Futbol Federasyonu (TFF) tarafından yürütülen Antrenör Eğitim Programları (AEP)’na kabul edilen gönüllü 20 futbol UEFA A antrenör adayı katılmıştır. Veriler, alan yazını ve pilot çalışmanın sonunda ulaşılan ve 5 sorudan oluşan yarı yapılandırılmış görüşme formu kullanılarak yüz yüze görüşmeler yoluyla elde edilmiştir. Veriler betimsel analiz tekniği çerçevesinde ve betimlemeye dayalı deneyimlerin ana temalara ayrılmasıyla özetlenerek yorumlanmıştır. Analiz sonuçlarına göre; çevrim içi toplantılara, seminer ve uygulama eğitimlerine, ölçme ve değerlendirme süreçlerine ve antrenör eğitim programının genel organizasyonuna yönelik antrenör deneyimlerinden oluşan bulgulara ulaşılmıştır. Sonuç olarak antrenör eğitim programlarından önce gerçekleştirilen çevrim içi toplantıların oryantasyon itibariyle daha nitelikli hale getirilmesi, seminer eğitimlerinde nitelikli doküman sağlanması, taktik animasyon programların kullanımına yönelik eğitim verilmesi, uygulama eğitimlere yönelik müfredatın uygulanabilir yoğunluğa indirgenmesi, ölçme değerlendirme süreçlerine yönelik antrenörler üzerinde oluşan sınav ve not kaygısına yönelik tedbirlerin alınması, kurs ücretlerinin daha makul miktarlara indirilmesi, seminer süresince konaklama ve lojistik gibi verilen hizmet kalitesine yönelik iyileştirilmelere gidilmesi AEP’in daha etkili ve verimli hale gelmesine yönelik önemli katkılar sağlayacağı düşünülmektedir
A Finite Element Modeling Approach for Analyzing the Cyclic Behavior of RC Frames
No full textNumerous approaches and inputs for nonlinear finite element analysis used for modeling reinforced concrete systems under cyclic loads have been outlined. Practitioners usually take into account a number of significant factors when modeling, for example deciding upon the constitutive relations, the connection among concrete and steel reinforcement, and the mesh sensitivities, in order to accurately simulate the nonlinear response of reinforced concrete under cyclic loads. Therefore, it is essential to thoroughly assess popular modeling approaches and develop a reliable modeling approach with reliability, stability, and consistency. A modeling technique and practical guidelines for nonlinear finite element analysis of reinforced concrete frames subjected to cyclic loading are described in this study, taking into account the influence of parameters such as dilation angle, stiffness recovery, friction coefficient, and mesh sizes. The hysteretic force–displacement behavior and load-carrying capacity of reinforced concrete frames subjected to cyclic loading have been compared using numerical and experimental curves. Discrete fracture paths are specified in the model’s geometry to achieve an accurate depiction of the stress distribution and an adequate fit of the hysteretic behavior. The proposed modeling approach provides a precise representation of the stress distribution and hysteretic behavior while keeping computational costs reasonable. © The Author(s) 2024
Serebral palsili çocuklarda hippoterapinin üst ekstremite fonksiyonları üzerine etkisi
No full textPurpose: The purpose of our study was to investigate the effects of hippotherapy on upper extremity functions in children with cerebral palsy (CP). Materials and Methods: The study was carried out with a quasi-hippotherapy design by evaluating the hippotherapy and control groups with pretests and posttests. Sixteen children with CP who were treated with 30 minutes of additional hippotherapy three times a week for five weeks were included in the hippotherapy group. Eleven children with CP who had conventional physiotherapy were recruited for the control group. Upper extremity functions were evaluated before and after the intervention using the Box and Block Test (BBT) and the Jebsen Taylor Hand Function Test (JTHFT). Results: There were no significant differences between the hippotherapy and control groups in terms of their baseline BBT and JTHFT scores. After 5-weeks, no statistically significant difference was found between the BBT scores of the hippotherapy and control groups. Significant increases were detected in all parameters of JTHFT in the posttest in the hippotherapy group, compared to the pretest. Moreover, in the posttest, a statistically significant difference was found between the hippotherapy and control groups in the parameters of turning over cards and picking up small objects, which subscales of JTHFT. Conclusion: In children with CP, hippotherapy provided in addition to conventional treatment was an effective practice, especially in improving fine motor skills in the hands
Frequency selective surface design for wearable applications
No full textBu tez çalışmasında giyilebilir uygulamalarda kullanılmak üzere, 6 GHz'in altındaki bantlarda filtreleme özelliği gösteren çoklu bant durdurma iletim cevabına sahip iki farklı, özgün Frekans Seçici Yüzey (FSY) tasarımı ve analizi sunulmuştur. Tasarım-1 olarak adlandırılan ve iki farklı frekansta durdurma bandına sahip yapıda alttaş olarak polyester keçe kumaş, Tasarım-2 olarak tanımlanan üç durdurma bandına sahip yapıda ise alttaş olarak yünlü keçe kumaş tercih edilmiş ve her iki tasarımda da iletken olarak bakır kullanılmıştır. Kullanılan kumaşlara ait elektriksel özellikler referans alınarak güçlü bir elektromanyetik analiz programı olan CST Studio Suite programı aracılığı ile FSY'lere ait tasarımlar gerçekleştirilmiş ve tasarımı yapılan yapılar için S21 (iletim) ve S11 (yansıma) frekans cevapları incelenmiştir. Kumaş FSY yapıların tasarımlarına ait parametre analizleri gerçekleştirilerek, tasarım parametreleri optimize edilmiş ve istenilen frekans bantlarında filtreleme özelliği göstermesi sağlanmıştır. Tasarım-1 sırasıyla 2.4 GHz ve 4.72 GHz frekanslarında iletim sıfırlarına sahip, 0.75 GHz ve 0.69 GHz bant genişliğinde iki durdurma bandı bulundurmaktadır. Tasarım-2 kumaş FSY yapısı ise 1.17 GHz, 3.74 GHz ve 4.72 GHz frekanslarında üç iletim sıfırına sahiptir. Bant genişlikleri ise; 0.65 GHz, 1 GHz ve 1.17 GHz'dir. Hem Tasarım-1 hem de Tasarım-2 TE ve TM polarizasyonlarda özdeş frekans cevaplarına sahiptir. Dolayısıyla her iki tasarım da polarizasyondan bağımsız frekans tepkisi özelliği sergilemektedir. Açısal kararlılık analizleri gerçekleştirilen yapılardan Tasarım-1 farklı geliş açıları için; 1.rezonans frekansı 2.4 GHz'de TE polarizasyon için 30º'ye kadar %5.83'lük bir sapma ile kararlı davranırken, TM polarizasyonda %2.5'lik bir sapma ile 60º'ye kadar kararlı davranmıştır. Tasarım-2'nin ise farklı dalga geliş açıları için 1. rezonans frekansında 60º'ye, 2 ve 3.rezonans frekansında 20º'ye kadar açısal kararlılık sergilediği görülmektedir. Tasarım-2 kumaş FSY yapısı; %90 yün karışımına sahip keçe kumaş alttaş üzerine, 0.035 mm kalınlıkta bakır bant ile 3×5'lik bir FSY dizisi biçiminde üretilmiş ve yansımasız odada serbest uzay ölçüm metodu kullanılarak iletim parametresi ölçümleri gerçekleştirilmiştir. Elde edilen ölçüm sonuçları benzetim sonuçları ile karşılaştırılarak yapılan analizlerin doğruluğu test edilmiştir
Investigation of the effects of some demographic characteristics of female athletes on emotional intelligence and life satisfaction; [Investigación de los efectos de algunas características demográficas de las deportistas sobre la inteligencia emocional y la satisfacción vital]
No full textIn many subjects and fields, emotional intelligence refers to the ability of individuals to understand, express and manage their own emotions and the emotions of others. Especially sport is known to have a significant effect on emotional intelligence. In this study, it was aimed to examine the effects of some demographic characteristics of female athletes on emotional intelligence and life satisfaction. The participants were all women and analyses were performed by taking into account age groups, sports branches and education departments. Emotional intelligence and life satisfaction scales were evaluated by factor analysis and the suitability of the data was confirmed by Bartlett's test. The internal consistency of the questionnaire was evaluated with Cronbach's alpha coefficients. Anova, Kruskal Wallis and Jonckheere-Terpstra tests were used to analyse the data. All analyses were performed with SPSS v22.0. 34% of the participants were 18-21 years old, 45% were 22-25 years old and 21% were over 26 years old. 31% were interested in team sports and 69% were interested in individual sports. The fields of education are 37% coaching, 32% physical education and sports teaching, 31% sports management. According to the factor analysis results, Bartlett's test p<0.001 and KMO coefficient 0.896 were found. Cronbach's alpha coefficients ranged between 0.583 and 0.924. While some factors differed according to age, no difference was found according to sport branch. While evaluation of own emotions and social skills differed according to departments, other factors did not differ. Participants over 26 years of age had low scores in the use of emotions and life satisfaction factors. These findings provide important clues for developing strategies for improving emotional intelligence and increasing life satisfaction. © 2024, Campus EDUCA SPORTIS S.L.. All rights reserved
EFFECT OF ASSISTIVE ROBOTIC TECHNOLOGIES ON QUALITY OF LIFE AND FUNCTIONAL INDEPENDENCE IN INDIVIDUALS WITH SPINAL CORD INJURY
No full textPurpose: To investigate the effect of assistive robotic technologies on quality of life, functional independence, and perceived fatigue level in individuals with spinal cord injury (SCI). Material and Methods: This research involved a cohort of 25 patients who had been diagnosed with SCI. To assess their progress, clinical assessments were administered both at the commencement and completion of a six-week robotic rehabilitation treatment regimen. The evaluations encompassed the use of the Spinal Cord Independence Measure (SCIM III) to measure their performance in daily living activities and mobility. Additionally, the quality of life was assessed using the World Health Organization Quality of Life Scale - Short Form (WHOQOL-BREF) scale, while the levels of fatigue experienced during rehabilitation were gauged using the Modified Borg Scale (RPE). Results: The participants' average age and BMI were 40.72 +/- 1.28 kg/m2 and 23.43 +/- 0.57 year. Statistically significant differences were found in self-care (p=0.006) and mobility (p=0.004) values of SCIM III scale compared to pretreatment values. WHOQOL-BREF General health status, Physical health, Psychological, Social relations and Environment sub-parameters all showed statistically significant differences compared to pre-treatment values (p<0.001). There was a significant decrease in the RPE value to determine the level of fatigue during exertion in robotic walking training (p<0.001). Conclusion: Assisted robotic rehabilitation approaches increased individual independence, quality of life and reduced fatigue during exertion in Individuals with SCI. We think that assisted robotic approaches applied in addition to traditional rehabilitation provide additional benefits in increasing the level of independence and quality of life of individuals with SCI in daily life and reducing fatigue during exertion