Effect of Impact Angle and Speed, and Weight Abrasive Concentration on AISI 1015 and 304 Steel Exposed to Erosive Wear

Refik POLAT

This study investigated parametrically the erosive wear behavior of AISI 1015 and 304 steel in different environmental conditions. The erosive wear tests were designed according to the L9 orthogonal array design of the Taguchi fractional factorial method. The experiments were carried out with the parameters of 3-level slurry concentration formed with silica powder (5, 15, and 25 wt.), 3-level impact velocity (265, 397.5, and 530 rpm), and 3-level impact angle (30°, 60°, and 90°). Surface roughness and weight loss were considered performance criteria in the experimental data assessed using the ...More

Renewable-based treatment solution of Reactive Blue 21 dye on fly ash as low-cost and sustainable adsorbent

Mehmet KOBYA

This study investigated the removal of Reactive Blue 21 (RB 21) dye from aqueous solutions by adsorption, evaluating the waste fly ash (FA). The effects of the parameters, such as initial dye concentration (100–750 mg/L), initial pH (2.0–8.0), adsorbent dose (1.0–4.0 g/L), and temperature (298–323 K) on the adsorption process were investigated. The optimum initial pH value was 2.0 for the highest RB21 dye removal (75.2 mg/g). At optimized conditions (pH 2.0, an adsorbent dosage of 1.0 g/L, a dye concentration of 750 mg/L, and an equilibrium time of 72 h), the highest adsorption capacity was fo ...More

Exploring the impact of university support on students' entrepreneurial intentions: evidence from Kyrgyzstan

Azamat MAKSUDUNOV

Whether university support is meaningful in increasing students' entrepreneurial intentions (EI) remains largely under-investigated, especially in the context of Central Asian countries. In this study, we attempted to address this question by examining the effects of university support (comprised of educational support, concept development support, and business development support) on students' EI. We employed a structured questionnaire to collect data from 793 student respondents enrolled in 13 universities in Kyrgyzstan and performed descriptive and inferential statistical analyses. Our anal ...More

Corporate environmental, social, and governance activities and financial reporting quality: An international investigation

Gökhan ÖZER

This paper examines the impact of firms' environmental, social, and governance (ESG) activities on financial reporting quality (FRQ). The study uses 45,877 firm-year observations from 65 countries between 2003 and 2021. In the research model, firm characteristics and macroeconomic and institutional structure characteristics of the countries are controlled for. This study finds that firms with higher ESG scores have higher FRQ. Additionally, our mediation analysis indicates that financial distress costs serve as a crucial mechanism through which ESG influences FRQ. Our findings are robust after ...More

Audit Committee and Timely Reporting: Evidence From Turkey

Gökhan ÖZER

This paper seeks to examine whether the characteristics of the audit committee impact the timely reporting represented by audit report lag (ARL), firm-based abnormal audit report lag (FAARL), and industry-based audit reports lag (IAARL). The sample of the study includes mostly hand-collected 2,284 firm-year observations obtained from Turkey's listed non-financial companies. Main regression results show that audit committee gender diversity, meeting frequency, and independence are negatively associated with timely reporting. Furthermore, additional analysis indicates the negative association be ...More

Numerical study on effect of process parameters on material extrusion 3D printing (ME3DP) for porous bone tissue engineering scaffolds

Refik POLAT

Bone tissue engineering (BTE) holds promise for treating bone defects, and 3D-printed porous scaffolds are pivotal for tissue regeneration. This study explores the impact of material extrusion 3D printing (ME3DP) process parameters (i.e., layer height and extrusion temperature) on 3D-printed porous scaffolds made of polyetherimide (PEI) material for BTE. The intricate relationships shaping scaffold dimensional accuracy, residual stresses, and warpage tendencies were unveiled using comprehensive numerical simulations. Our findings reveal that higher layer heights enhance dimensional stability, ...More

Digital entrepreneurship in tourism

Mustafa Murat KIZANLIKLI | Narıngül MARGAZİYEVA

Molecular imprinted polymers: important advances in biochemistry, biomedical and biotechnology

Kalıypa SALİYEVA | Bakıt BORKOYEV

Molecularly imprinted polymers (MIPs) are handmade receptors that mimic the binding of natural antibodies. In other words, MIPs can selectively bind to the target molecule and qualify as bio-inspired synthetic materials. Today, MIPs are used extensively and are being developed further for biological applications. High cost and time consuming techniques are compelling factors for the field of biochemistry, biomedicine and biotechnology (3B), and there is an urgent need for an alternative, cheap, easy to produce, fast and effective method in these fields. MIPs stand out as a promising way for th ...More