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Fracture and dynamic mechanical analysis of seawater aged aluminum-BFRP hybrid adhesive joints
No full textAdhesively bonded hybrid FRP-aluminium structures have recently become an efficient solution for marine engineering applications. However, polymer adhesives' bond performance is sensitive to the marine environment due to polymer and interfacial degradation. This study aims to develop mode I, mode II delamination toughness, and Tg data as a comprehensive design guideline for hybrid BFRP-aluminum modified-adhesively bonded joints subjected to seawater aging. The hybrid joints were exposed to long-term seawater aging (for 6 months) to reveal their fracture and thermomechanical performances. Besides, the adhesive was reinforced with HNTs to increase fracture resistance with additional nano-scale toughening mechanisms and to delay the water absorption. After the long-term aging, reinforced adhesively bonded joints exhibited -36% higher fracture toughness than neat adhesively bonded joints. Moreover, DMA was conducted on miniaturized SLJ samples, which revealed that HNT modified adhesive joints showed -11.5 degrees C higher Tg. The calculated aging rates also proved the effectiveness of HNTs modification on the epoxy adhesive's aging performance since the HNT reinforced adhesive represented 43% lower aging rates in terms of storage modulus. It is considered that experimental results will help comprehend long-term aging influences on the composite-aluminum hybrid designs' fracture and thermomechanical performances. These exciting findings will pave the way for the safe use of high stiffness and cost-effective aluminum-BFRP hybrid structures for the marine industry.TUBITAK [120M369]Acknowledgment The authors sincerely thank TUBITAK for financial support (Project Grant No: 120M369)
Assessing the performance of Turkish science pre-service teachers in a TPACK-practical course
No full textThis study assesses the performance of Turkish science pre-service teachers (PSTs) in a TPACK-Practical Course that consists of the training course and lesson-plan-micro-teaching stages. The subjects of the study were 46 PSTs (19 males and 27 females). In this study, after PSTs took a TPACK training course, they created a TPACK-based lesson plan and presented it to their classmates through micro-teaching. Data sources included lesson plans and video recordings of lesson presentations. Researchers developed and used a rubric of TPACK-based learning environments to evaluate the data sources. The rubric consisted of 12 items, and each item contained five performance levels. Researchers analyzed the data by using descriptive statistics and the Wilcoxon signed-rank test. There was a significant increase in the total score of TPACK among the PSTs after the course. There was also a significant increase in the items guiding, providing active participations of students, making assessment and evaluation, appropriateness of chosen teaching methods, and accuracy of the given information/concepts when teaching science subjects with technology. Possible reasons for this positive effect include using worksheets with technological tools such as simulation, the influence of the course lecturers as role models, the introduction of new technologies to the PSTs in the training course, and using class discussions to provide feedback
A new kind of F-contraction and some best proximity point results for such mappings with an application
No full textIn this paper, we aim to present a new and unified way, including the previously mentioned solution methods, to overcome the problem in [7] for closed and bounded valued F-contraction mappings. We also want to obtain a real generalization of fixed point results existing in the literature by using best proximity point theory. Further, considering the strong relationship between homotopy theory and various branches of mathematics such as category theory, topological spaces, and Hamiltonian manifolds in quantum mechanics, our objective is to present an application to homotopy theory of our best proximity point results obtained in the paper. In this sense, we first introduce a new family, which is larger than F* that has often been used to give a positive answer to the problem. Then, we prove some best proximity point results for the new kind of F-contractions on quasi metric spaces via the new family. Additionally, we show that the note given by Almeida et al. [4] is not valid for our results. Therefore, our results are real generalizations of fixed point results in the literature. Moreover, we give comparative examples to demonstrate that our results unify and generalize some well-known results in the literature. As an application, we show that each homotopic mapping to phi satisfying all the hypotheses of our best proximity point result has also a best proximity point
Deep Clustering via Center-Oriented Margin Free-Triplet Loss for Skin Lesion Detection in Highly Imbalanced Datasets
No full textMelanoma is a fatal skin cancer that is curable and has dramatically increasing survival rate when diagnosed at early stages. Learning-based methods hold significant promise for the detection of melanoma from dermoscopic images. However, since melanoma is a rare disease, existing databases of skin lesions predominantly contain highly imbalanced numbers of benign versus malignant samples. In turn, this imbalance introduces substantial bias in classification models due to the statistical dominance of the majority class. To address this issue, we introduce a deep clustering approach based on the latent-space embedding of dermoscopic images. Clustering is achieved using a novel center-oriented margin-free triplet loss (COM-Triplet) enforced on image embeddings from a convolutional neural network backbone. The proposed method aims to form maximally-separated cluster centers as opposed to minimizing classification error, so it is less sensitive to class imbalance. To avoid the need for labeled data, we further propose to implement COM-Triplet based on pseudo-labels generated by a Gaussian mixture model (GMM). Comprehensive experiments show that deep clustering with COM-Triplet loss outperforms clustering with triplet loss, and competing classifiers in both supervised and unsupervised settings.TUBA GEBIP 2015 award; TUBA BAGEP 2017 awardThe work of T. Cukur was supported by TUBA GEBIP 2015 and BAGEP 2017 awards
Comparison of Two Clinical Chemistry Analyzers by Total Analytical Error and Measurement Uncertainty
No full textBackground: Although analytical errors contain a small portion of laboratory errors, they are important in terms of intervention ability and practicality of follow-up by laboratory professionals. Also, from this point of view, the test results' quality, reliability, and accuracy are crucial to laboratories. Therefore, to determine analytical per-formance parameters for quality management in the analytical phase, clinical laboratories utilize total analytical error (TAE), bias, coefficient of variation (CV), and uncertainty of measurement (MU). Methods: Fifteen biochemistry parameters were compared with Beckman Coulter AU 5800 for 2017 -2018 and Roche Cobas 8000 for 2019 -2020 in terms of TAE and MU. The results were evaluated between devices and com-pared with the EuBIVAS, CLIA, RCPA, PRDEQA%, pUQEAS%, pU%, and TEa-TR datasets.Results: There were no significant differences between the devices for the mentioned periods. Device performances resulted in similar outcomes. During our four-year study, nearly all of our tests failed for EuBIVAS, RCPA, and pU%. On the contrary, almost all of our parameters gave valid results according to the CLIA, PRDEQA%, pUQEAS%, and TEa-TR ranges.Conclusions: It is crucial to distinguish between mistake and uncertainty. The discrepancy between the mea-sured value and the 'actual value' is called error. Uncertainty is a measure of how confident you are in the mea-surement outcome. We endeavor to remedy any known inaccuracies wherever feasible by applying adjustments from calibration certifications. On the other hand, any inaccuracy whose value is unknown is a cause of doubt.(Clin. Lab. 2023;69:xx-xx. DOI: 10.7754/Clin.Lab.2022.220846
İngiltere’nin Birinci Dünya Savaşı Öncesi İran Siyaseti ve İki Sadrazamın Öldürülmesi (1800-1907)
No full textİngiltere, Hindistan güzergâhındaki İran’a Safevi döneminden itibaren nüfuz etmeye çalışmış, Fars Körfezi’ndeki Portekiz egemenliğini ortadan kaldırdıktan sonra iç kısımlara yönelmiş ve sömürgecilik esasına dayalı siyasetini icraya koymuştur. Hindistan’a üçüncü bir devletin yaklaşmaması için bütün diplomatik manevraları devreye sokmuştur. Kaçar idaresinin ilk yıllarında Napolyon’un İran ile Finkestein’de imzaladığı askeri ittifak anlaşmasını, Rusya ile Tilsit’te İran’ın taksimini içeren anlaşmayı imzalamakla geçersiz kılmıştır. Rusya’nın güneye sarkmamasını masa başında yaptığı diplomatik manevralar ve İran’ın kuzey toprakları ile Osmanlı boğazlarını vaat ederek sağlamıştır. Kaçar idaresinin iki sadrazamı bu siyasetin farkında olarak tedbirler almış, ülkelerinin İngiltere nüfuzundan kurtulması için çaba göstermişlerdir. Muhammed Şah’ın sadrazamı Mirza Ebul Kasım Ferahani (Kaimakam) ve Nasırüddin Şah’ın sadrazamı Mirza Taki Han (Emir-i Kebir), milli unsurlara dayanarak ıslahatlar yapmışlardır. Askeri ve teknik gelişmeler için Avrupa’ya öğrenciler göndermişlerdir. Askeri ıslahatlar için istihdam edilen İngiliz ve Fransız subayların İran yararına çalışmadıklarını fark ederek başka ülkelerden uzmanlar istihdam etmişlerdir. Devlet idaresinde rüşveti ortadan kaldırarak israfı önlemişlerdir. Her iki sadrazamın yaptıkları ıslahatları kendi çıkarına uygun bulmayan İngiltere, zayıf bir İran için diplomatik hilelerle başvurmuştur. Bu siyaseti fark edemeyen Kaçar şahları, aldıkları borç paralar ve pervasızca yabancı sermayedarlara verdikleri imtiyazlar ile ülkelerini İngiliz ve Rus işgaline adım adım götürmüşlerdir. Çalışmamızda Birinci Dünya Savaşı öncesinde İngiltere’nin İran siyaseti ortaya konulurken, bu siyasete karşı çıkarak milli unsurlara dayalı ıslahat yapmaya çalışan iki sadrazamın nasıl gözden düşürüldüğü ve niçin ortadan kaldırıldıkları dönemin ana kaynakları ile izah edilmeye çalışılacaktır. İngiltere’nin İran siyaseti ortaya konulurken, tarihte aynı siyasetin ayrılmaz parçası olan Afganistan kısmı da ele alınacaktır
Energy Consumption and Financial Development: Evidence from MENA Countries with Panel Hidden Cointegration
No full textEnergy is an important parameter that gives clues about the developments in economies. Energy consumption (EC) in countries gives a summary of the economic structures of those countries. Today, the attention-grabbing component of economic growth, apart from the real sector determinants, is considered to be financial development. In this study, the relationship between EC and financial development in MENA countries is examined. Econometric analyzes are carried out by Hatemi J (2011) Panel Hidden Cointegration Test and Panel VECM analysis in the study covering the period between 1980 and 2017. The test results have showed that there is no cointegration between the original values of the variables, but there is a long-term relationship between some of the positive and negative components. Therefore, it has been determined that there is a hidden cointegration between the series. In light of these findings, the cointegration and especially the long-term causality relationship between the components of the variables reveal that the change in financial development indicators is effective on energy consumption
Evaluation of the Published Articles in Education Field: A Bibliometric Analysis
No full textThe aim of this study is to analyze the articles published as Turkey-addressed in SSCI and ESCI indexed journals in the Education & Educational Research (E&ER) thematic field in the Web of Science (WoS) databases in the last decade. For this purpose, the published articles as Turkey-addressed between the years 2010 and 2019 were examined with respect to the distribution of the number of articles, the number of citations and uncited articles, journals' indexes, and Turkey's ranking in international field and universities' rankings, and the distribution of the articles to the journals. In the study, it was clear that the number of articles published as Turkey-addressed in the educational field tended to increase over the years, and this increase is due to the number of articles in ESCI indexed journals. Moreover, it has been determined that Turkey is ranked 6 in the total number of articles in the educational field when compared to other countries. The top three universities that contribute are (i) Hacettepe University, (ii) Gazi University, and (iii) Middle East Technical University. In addition, the three most published journals are (i) Education & Science, (ii) Educational Sciences in Theory and Practice, and (iii) Hacettepe University Journal of Education. Based on the research data, it can be said that although the publications of our country seemed to be at a good level quantitatively in the international field, we remained in a local state on a global scale according to the journal addresses of the published articles
AMIN MAALOUF, ÖLÜMCÜL KİMLİKLER
No full textLübnan asıllı Fransız yazar Amin Maalouf, Güney Arabistan’dan Lübnan’a gelip yerleşmiş Hristiyan bir aileye mensuptur. 1976’da Fransa’da yaşamaya başlamakla birlikte eserleriyle kökeninin ait olduğu Ortadoğu coğrafyasına olan ilgisini sürdürmektedir. Kendisini tanıtırken ortaya koyduğu çok yönlü kimliğinin ve Lübnan’dan Fransa’ya göçen ve halen orada yaşayan bir entelektüel oluşunun onun düşünce yapısını etkileyen çok önemli iki unsur olduğu anlaşılmaktadır. Eserlerinde daha çok kimlik, kültür, göç, çatışma, çatışma çözümü konuları üzerinde odaklanmaktadır. Çok kültürlü bir toplumsal yapının hakim bulunduğu Ortadoğu İslam coğrafyasında yaşanan sorunlara ilişkin ilgi düzeyi hayli yüksektir. Ölümcül Kimlikler eseri de 20. Yüzyılın son çeyreğinde Dünya gündeminde ön sıralarda yer tutan kimlik ve kültür farklılıkları ve çatışmalarının çözümü üzerine kaleme alınmış, ilk baskısı 2000’de yapılmış deneme türünde bir eserdir
The Relationship Between GPX1 Pro198Leu Manganese Superoxide Dismutase Ala16Val Variants and Obstructive Sleep Apnea Syndrome
No full textObjective: To investigate the association between obstructive sleep apnea syndrome (OSAS), glutathione peroxidase-1 (GPX1) Pro198Leu, and manganese superoxide dismutase (MnSOD) Ala16Val gene polymorphisms. Materials and Methods: The study included 81 patients with OSAS and 75 healthy controls from the Turkish population. Genotypes of the MnSOD rs4880 T/C (Ala16Val) and GPX1 rs1050450 T/C (Pro198Leu) variants were determined via single-nucleotide polymorphisms genotyping analysis, which is based on simple probe melting curve analysis. Results: The frequencies of the MnSOD rs4880 T/T, T/C, and C/C were 35.8%, 50.6%, and 13.5% in patients with OSAS and 34.6%, 49.3%, and 16% in the controls, respectively. No statistically significant difference was determined between patients and controls in terms of MnSOD rs4880 variant genotype and allele distribution (odds ratio: 1.07; 95% confidence interval: 0.68-1.69; p>0.05). The frequencies of the GPX1 rs1050450T/T, T/C, and C/C were 12.0%, 38.5%, and 49.4% in patients with OSAS and 13.1%, 42.1%, and 44.7% in the controls, respectively. No statistically significant difference was determined in the genotype and allele frequencies of the GPX1 rs1050450 variant between the patients and controls (p>0.05). Additionally, the haplotype was examined on the basis of combined genotypes for the two variants in patients with OSAS and controls, which revealed no statistically significant correlation. Conclusion: Our study indicates that two polymorphisms in these antioxidant enzymes were not associated with Turkish patients with OSAS. Further studies may reveal an association between these two polymorphisms with some clinical parameters in patients with OSAS