Kök, Mediha; Aydoğdu, Kumruya; Kanca, M. Sait; Qader, Ibrahim Nazem; Öner, Ecem; Coşkun, Meltem

Heusler shape memory alloys are important for many applications due to their typical magnetic and shape memory behaviors. In this study, a Ni50Mn36Sn12Co2 (at.%) alloy was manufactured by arc-melting technique, then the ingot cooled to ambient temperature in the natural atmosphere. Three different temperatures, including 500 °C (773 K), 700 °C (973 K), and 900 °C (1173 K), was selected for aging the samples cut from the main ingot. The impact of aging on the crystalline; microstructure; caloric; and magnetic properties of the alloys were investigated through x-ray diffraction (XRD); scanning electron microscope; differential scanning calorimetric (DSC), differential thermal analysis, and thermal gravimetric (TG); and physical property measuring system was investigated, respectively. The aging in different temperatures led to the shift DSC curve, such that the martensitic phase transformation temperatures of the sample aged at 773 K increased, however, the transformation at 973 and 1173 K decreased compared to the as-casted alloy. The different phase transformation behavior showed that the alloy aged at 773 K has the maximum elastic energy, enthalpy and entropy change compared to the reset of samples, on the other hand, its crystallite sized obtained from XRD analysis comparably diminished. Besides, the TG analysis revealed that the mass gain almost occurs at a temperature above 773 K, therefore the magnetization of the alloys aged at 973 and 1173 K decreased due to a thin oxide layer formed on the surface of the alloys.

AtıfScopus5·WoS5·OpenAlex7

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Kocabaş, Mehmet; Kutluyer, Filiz; Erişir, Mine; Benzer, Fulya

l-arginine is a versatile amino acid and precursor of nitric oxide that provides protection for preventing free radical damage. Herein, experiments were designed to clarify the effect of l-arginine supplementation on the sperm motility of a threatened trout, Coruh trout Salmo coruhensis. Activation solution was supplemented with levels of 0 mM (Control), 2 mM, 4 mM, and 8 mM l-arginine, and motility and survival of sperm cells were assessed. The selected concentrations were determined according to results of our preliminary experiments. The sperm motility rates at l-arginine concentrations of 0, 2, 4, and 8 mM were 73.33 ± 5.77%, 76.67 ± 5.75%, 80.01 ± 0.01%, and 90.00 ± 0.05%, respectively; notility durations were 21.67 ± 2.08, 32.33 ± 3.79, 32.67 ± 1.15, and 37.00 ± 6.38 s, respectively. Significant effect of l-arginine supplementation was determined on the percentage and duration of motile spermatozoa (p < 0.05). The maximum increment was evoked at the greatest concentration (8 mM). Here, we showed that l-arginine supplement can improve sperm motility of S. coruhensis.

AtıfScopus1·WoS1·OpenAlex2

İncele

Albayrak, S.; Cinar, A. E. Korkmaz; Paksoy, M. Y.; Aksoy, A.

The antioxidant activities of methanol (ME), ethanol (EE), water (WE) and ethyl acetate (EAE) extracts of four Inula helenium L. taxa (I. helenium ssp. orygalis (Boiss.) Grierson, I. helenium ssp. pseudohelenium Grierson, I. helenium ssp. turcarasemosa Grierson and I. helenium ssp. vanensis Grierson) were investigated. The phosphomolybdenum assay, beta-carotene linoleate bleaching and DPPH radical scavenging activity were used to evaluate the antioxidant capacity. The total phenolic contents determined by Folin-Ciocalteu assay of the extracts ranged from 4.18 to 102.91 mg gallic acid equivalents (GAE)/g dry extract. The extracts showed considerable effect on reducing the oxidation of beta-carotene. The highest radical scavenging activity was obtained for ME of I. helenium ssp. orygalis in DPPH assay. ME, EE and EAE of four Inula helenium taxa showed significant antibacterial activity against 13 bacteria tested. WEs had no inhibitory effect against bacteria tested except for I. helenium ssp. orygalis. EE of I. helenium ssp. orygalis was only effective against C. albicans.

AtıfWoS8

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