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- MakaleAçık Erişim2026Dynamic and Mechanical Properties of Nanoparticle Doped Aramid/Glass Fiber Reinforced Interply Hybrid Composites
Sadik, Ayşegül Cansu; Karabudak, Filiz; Kula, Muhammed Emin
In this study, the mechanical and dynamic properties of glass/aramid interply hybrid composites reinforced with four different nanoparticles were investigated. Firstly, matrix modification was performed and composite plates were manufactured by hand lay-up technique. Silicon dioxide (SiO2), graphene (GNP), silver (Ag) and cerium oxide (CeO2) nanoparticles were added to the epoxy matrix as reinforcement. With the addition of nanoparticles, the highest tensile (16%) and flexural (67.3%) strengths were observed in Ag reinforced composites. Tensile (16.8%) and flexural (14.4%) strengths decreased with the addition of graphene nanoparticles. Tensile and flexural tests revealed delamination, matrix and fibre rupture in all plate types. As a result of modal analysis, the highest natural frequency values and the lowest damping ratios were determined in the FFBC boundary condition. The addition of nanoparticles improved the mechanical properties of the composites in general.
- MakaleYayıncıda açık erişim2025The Effect of Heavy Metals in Mining Emissions on Worker’s Blood Lead Levels: A Case Study of The Gumushane Zn-Pb Mine, Turkey
Bozbeyoğlu, Pınar; Doğan, Onur; Budak, Burhan
The wastewater from mining facilities contains toxic elements such as arsenic (As), cadmium (Cd), chromium (Cr), manganese (Mn), zinc (Zn), and lead (Pb). If not disposed of correctly, it can lead to environmental pollution in case of accidents or overflow. Lead-zinc mining activities pose a significant risk of high blood lead levels (BLLs) among workers. Therefore, monitoring the blood lead levels of workers exposed to these heavy metals, especially lead, is crucial. This study aims to determine the levels of potentially harmful elements in the wastewater dam of the largest Zn-Pb mine in the Black Sea Region. It also seeks to assess the environmental and human health risks comprehensively. Additionally, the study aims to establish a relationship between the levels of lead in the mining wastewater in Gumushane and the lead levels accumulated in the blood of workers exposed to this metal. The study analyzed heavy metals such as As, Zn, Cu, Sb, and Pb in mining wastewater using Inductively Coupled Plasma – Mass Spectrometer (ICP-MS). The results indicated high levels of Pb in the studied wastewater. Furthermore, the blood lead levels of workers in the mining area (n=30; mean: 7.42 μg/dL) exceeded background levels (>40 μg/dL). These results suggest a significant relationship between the presence of lead in wastewater and high lead levels in the blood of individuals with high exposure to concentrated lead.
- MakaleAçık Erişim2025Inhibition Effect of Diosmin Flavanoid on Some Metabolic Enzymes and Investigation of Antioxidant Properties
Balci, Neslihan
Diosmin is a natural flavonoid obtained by dehydrating flavanone glycoside hesperidin. This study evaluated the inhibition effects of diosmin flavonoid on human carbonic anhydrases (hCA I and hCA II) and acetylcholinesterase (AChE) enzymes, which are linked to various health issues, and compared the results with standard drugs. The antioxidant potential was assessed using five assays, namely DPPH, ABTS, FRAP, CUPRAC and Fe3+ reducing assays. The results determined that diosmin didn’t exhibit strong antioxidant activity. Additionally, the inhibition effects of diosmin on hCA I, hCA II, and AChE enzymes were examined. It effectively inhibited hCA I and hCA II enzymes with Ki values of 3.84±0.63 nM and 15.64±1.90 nM, respectively (Table 1). For comparison, the Ki values of the standard drug AZA were 1.44 ± 0.32 nM for hCA I and 3.66 ± 0.25 nM for hCA II. On the other hand, diosmin effectively inhibited AChE enzymes with Ki values of 9.31±2.40 nM. The Ki values of the standard drug Tacrine was 6.22±1.95 nM for AChE. These findings suggest that diosmin may serve as a selective enzyme inhibitor, particularly for hCA I, but has limited antioxidant capacity. Diosmin exhibited relatively weak antioxidant activity compared to standard antioxidants.
- MakaleAçık Erişim2024Determination of Antioxidant Capacities of Extracts of Sorbus subfusca (ledeb. ex. nordm.) boiss
Kocabaş, Selahattin; Topal, Fevzi
Sorbus subfusca (ledeb. ex. nordm.) boiss. (Sorbus subfusca) belongs to the Rosacese family. It is commonly referred to as highland rowan. It is an endemic species found only in the eastern Black Sea Region of Turkey and in a few countries on the Asian Continent. Both water (WESS) and ethyl alcohol (EESS) lyophilized forms were used as extracts. Different reducing capacity methods and radical scavenging activity methods were used to study the antioxidant activities of the extracts. Total phenolic compounds were calculated as 43.5 (WESS) and 43.0 (EESS) µg GAE/mg extract. This value is an indication that it can take place in plants with high phenolic content. Peroxidation inhibition percentages of linoleic acid emulsion at 20 µg mL-1 concentration for WESS and EESS; WESS was calculated as 70.93% and EESS as 82.63%. The high antioxidant capacity of Sorbus subfusca, an endemic species, brings up the preference of natural products as antioxidants. It is thought that these studies will draw a new path to the literature, especially alternative medicine and pharmacological studies.
- MakaleAçık Erişim2024Exploring the Impacts of Angelica purpurascens Extracts on Anticholinergic, Antidiabetic, Antibacterial Potential, and Antioxidant Capacity
Topal, Meryem; Topal, Fevzi; Yilmaz, Fırat
In Kars-Sarıkamış-Soğanlı, Angelica purpurascens (A. purpurascens) emerges as a promising natural antioxidant source. Extracts from its leaves, branches, and flowers underwent thorough bioanalytical assessments. The leaf extract exhibited the highest concentrations of herbal flavonoids (45.22 µg QE/mg extract) and total phenolics (28.96 µg GAE/mg extract). Branch extracts demonstrated significant enzymatic activity against AChE and BChE with IC50 values of 37.26 mg/mL and 9.08 mg/mL respectively. The flower extract displayed notable antibacterial properties. This study sheds light on the therapeutic potential of A. purpurascens ethanol extracts, suggesting benefits for Alzheimer’s, cell damage-induced diseases, and diabetes mellitus. It pioneers new enzymatic and antioxidant insights and contributes to understanding this abundant Türkiye species. A. purpurascens holds promise for pharmaceutical exploration, offering potential solutions for challenging health conditions.
- DergiJournal of the Institute of Science and Technology