İnşaat Mühendisliği Bölümü Makale Koleksiyonu

The Derivation of Vertical Damping Reduction Factors for the Design and Analysis of Structures Using Acceleration, Velocity, and Displacement Spectra

Mon, 01 Jan 2024 00:00:00 GMT

The Derivation of Vertical Damping Reduction Factors for the Design and Analysis of Structures Using Acceleration, Velocity, and Displacement Spectra Rouabeh, Aicha; Benahmed, Baizid; Palanci, Mehmet; Aouari, Issam Damping reduction factors (DRFs) play a vital role in the seismic design of structures. DRFs have been widely studied due to their primary importance to the lateral resistance of structures subjected to earthquakes. On the other hand, devastating earthquakes have occurred all over the world, and recently, the Kahramanmara & scedil; earthquakes in Turkey revealed the import of the vertical component of earthquakes and their impact on structures and infrastructures. Considering the importance of this parameter, this paper aims to develop new damping reduction factor (DRF) equations for the acceleration (DRFa), velocity (DRFv), and displacement spectra (DRFd) of the vertical components of earthquakes. For this purpose, 775 real ground motion records were selected from the Pacific Earthquake Engineering Research (PEER) strong motion database, and the vertical elastic response spectra of selected records were computed according to linear dynamic analysis. Taking the 5%-damped vertical response spectra as the target, the vertical spectral damping reduction factors (DRFa, DRFv, and DRFd) were computed for 1%, 3%, 10%, 15%, 20%, 30%, and 40% damping ratios. The effect of the earthquake magnitude, distance, and soil types on the DRFs was investigated. The results indicated that magnitude, distance, and soil type had no particular effect on the trend in the DRFs. Based on the evaluations, extensive statistical analyses were carried out, and new prediction equations were developed according to the nonlinear regression method. The developed equations were then compared to those found in the literature and seismic design codes. The comparisons proved that the proposed DRFa, DRFd, and DRFv models are strongly compatible with real DRFs and show strong robustness compared to existing models.

Practical equations for constitutive model of design-oriented FRP-confined concrete rectangular members

Mon, 01 Jan 2024 00:00:00 GMT

Practical equations for constitutive model of design-oriented FRP-confined concrete rectangular members Palanci, Mehmet; Subasi, Ilker The strengthening with Fiber Reinforced Polymer (FRP) offers one of effective solution to increase strength, axial load and deformation capacity of reinforced concrete (RC) members. However, the use of FRP-confined models can diverge in reflecting FRP confinement behavior, and they require significant computational effort and time. Moreover, the use of these models and their impact on member responses is not studied. To address this, several design-oriented FRP-confined concrete models were utilized and compared by using axial load-moment interaction diagrams and the moment-curvature relationship. Comparisons revealed that compressive strength of FRP-confined members could increase to 2.5 times while axial strain capacity could increase 4.0 times compared to unconfined ones depending on FRP-confined model. Based on the statistical analysis of numerous analytical sections covering broad-range properties of FRP material, practical equations were developed for predicting compressive strength and strain at ultimate for the design and analysis of FRP-confined RC sections. The proposed equations were then subjected to a comparison with analytical and various experimental studies, and their impact on the moment-curvature responses was investigated. Results indicated that proposed equations were in a good agreement with analytical models by the correlation coefficient higher than 0.97. The mean residuals between proposed equations and experimental results were also found around the 10 %, showed that proposed model could capture the stress-strain behavior of FRP-confined concrete. Moment-curvature response produced by proposed model and existing FRP-confined models were also found comparable with experimental results. © 2024 Elsevier Ltd

miR-3653-3p Expression in PBMCs: Unveiling the Diagnostic Potential for Ovarian Cancer

Mon, 01 Jan 2024 00:00:00 GMT

miR-3653-3p Expression in PBMCs: Unveiling the Diagnostic Potential for Ovarian Cancer Delek, Fatma Seher Pektopal; Tuncer, Seref Bugra; Odemis, Demet Akdeniz; Erciyas, Seda Kilic; Erdogan, ozge Sukruoglu; Saip, Pinar; Yazici, Hulya Ovarian cancer is typically diagnosed at an advanced stage, recurs early and often, and currently lacks effective treatment. Therefore, overall survival and progression-free survival are relatively short for this disease. Sensitive and specific biomarkers for early diagnosis and follow-up for effective treatment of the disease are currently lacking. MicroRNA (miRNA/miR) expression studies are widely used in cancer research. Disruption or malfunction of miRNAs, a class of noncoding small RNAs, has been implicated in cancer progression in several publications. Of note, the expression of a series of miRNAs is known to differ in ovarian cancer. In cancer research, it is crucial to analyze expression patterns in both cancer patients and healthy individuals to identify cancer-specific biological markers and to understand their role in cancer. In the present study, the expression levels of miR-3653-3p in the peripheral blood mononuclear cells (PBMCs) of 150 patients with high-risk ovarian cancer were determined, including those with a family history of cancer or an early-age diagnosis of ovarian cancer, as well as 100 healthy individuals. The results were then compared between the two groups. The expression level of miR-3653-3p in the PBMCs of patients with ovarian cancer was determined to be 9.49-fold higher than that in the healthy control group, and this result was statistically significant (P < 0.001). In addition, receiver-operating characteristic curve analysis of PBMC showed statistical significance of miR-3653-3p in discriminating ovarian cancer patients from healthy subjects (P < 0.001). These results suggest that miR-3653-3p detected in peripheral blood may be used as a non-invasive biomarker for ovarian cancer.

To internalize or not? Addressing key differences between Turkish migrant and native workers in construction employment

Mon, 01 Jan 2024 00:00:00 GMT

To internalize or not? Addressing key differences between Turkish migrant and native workers in construction employment Yilmaz, Ismail Cengiz; Tekin, Hamdi PurposeMigration is on the rise due to globalization and human mobility. This has led to increased impacts that have affected many industries, including the construction industry. A large number of migrants are employed in the construction sector, and employers are challenged to make sure all employees are properly integrated to meet the demands needed for construction projects. This article addresses key differences between migrant and native workers to help hiring departments in the construction industry analyse workers' attitudes based on cultural and motivational factors to have the workforce they need to succeed.Design/methodology/approachThe research used both quantitative and qualitative surveys. A two-part questionnaire, designed through a comprehensive literature review, was carried out to identify key differences between native and migrant workers. The data were obtained and then analysed using different statistical approaches, including factor analysis protocol, factor structure model, reliability analysis, relative importance index and nonparametric test analysis. A semi-structured interview was then conducted to discuss all the findings.FindingsThe study indicated that migrant workers, compared to natives, tend to give more importance to their working environment, particularly accommodation, work safety and relations with teammates. Also, migrants typically take a socialistic approach instead of an individual approach while at work and reveal an extensive range of behaviours based on a sense of belonging. It might be more important for migrants to have a place in society, to have a settled life and to be integrated into an established order than to improve their rights and benefits. On the other hand, the study argued that native workers tend to prioritize their benefits at work, such as regular payments for overtime and insurance premiums. Their behaviours might carry a more neutral and individual attitude as well as specific cultural traces.Research limitations/implicationsThe study is limited to a sample of participants in the Turkish construction sector. Further research based on more cultural models and motivational factors with a larger group of respondents from different countries could offer better results. The results of the study might not apply to a broad context due to many other factors that affect worker behaviours, such as geography, cultural structures and working conditions. Despite these drawbacks, the present paper may help employers and other stakeholders understand the best way to incorporate migrants into the construction industry.Originality/valueThis research is very important for the construction industry in various countries that are currently employing thousands of migrants. Being able to address the key differences between migrants and native workers based on cultural and motivational factors might help with engagement and create a level of harmony in the field for greater productivity.