Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2023Scopus SJRQ3/r/munzur/1983
  Production of SBS Reinforced Polyester Composite: Characterization of Physical and Chemical Properties

  Şahal, Hakan; Aydoğmuş, Ercan

  In this study, dissolved styrene butadiene styrene (SBS) copolymer is homogeneously reinforced into orthophthalic unsaturated polyester (UP) resin. Polyester composite production is carried out with the help of methyl ethyl ketone peroxide (MEKP) and cobalt octoate (Co Oc) catalysts. The density, Shore D hardness, thermal conductivity coefficient, thermal stability, morphological surface structure, and chemical bond structure of the obtained composite have been examined. According to the results, SBS reinforcement decreases the density of the composite and increases the thermal conductivity coefficient. The addition of SBS at different weight ratios (1%, 3%, 5%, 7%, and 10% w/w) reduces both the hardness and thermal stability of the polyester composite. According to the test and analysis results, 5 wt.% SBS reinforced polyester composite production is determined as the optimum ratio. 7 wt.% and above SBS reinforcement negatively affect the physical and chemical properties of the obtained composite. For example, when 10 wt. % SBS reinforced composite is examined by scanning electron microscope (SEM), and irregular pores are observed in the surface morphology. Also, it is understood by Fourier transform infrared spectroscopy (FTIR) that there is a physical interaction between SBS and polyester and that no chemical bond is formed. The thermal decomposition behavior of the composite has been determined according to the decrease in the activation energy. As SBS ratio increases, it is understood that the thermal stability of the product obtained with the decrease in the activation energy of the polyester composite weakens.

  AtıfScopus2

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• MakaleYayıncıda açık erişim2020Scopus SJRQ4/r/munzur/3587
  Assessment of elemental content, antioxidant activity, and total phenolic content of vitis sylvestris gmelin

  Ayhan, Nagihan Karaaslan

  In this study, we determined the Cu, Fe, Mn, and Zn contents of Vitis sylvestris Gmelin using flame atomic absorption spectrometry (FAAS), and examined the antioxidant properties of Vitis sylvestris Gmelin using radical scavenging capacities and total phenolic content tests. We found the average elemental contents; Cu, Fe, Mn, and Zn as 1.506 ± 0.042 mg/kg, 0.796 ± 0.020 mg/kg, 2.333 ± 0.033 mg/kg, and 3.191 ± 0.262 mg/kg, respectively. When we examined the antioxidant activity tests applied to different extracts, we determined the highest extraction yield with the methanol extract. DPPH radical scavenging activity, ABTS radical scavenging activity, and total phenolic content values in methanol extract were determined to be respectively 3.957 ± 0.146 mg TEAC/g fw, 9.062 ± 0.273 mg TEAC/g fw, and 2.365 ± 0.028 mg GAE/g fw. When we evaluated the antioxidant activity and total phenolic content results for all extracts statistically, we determined that there was generally a statistically significant difference between each extract (p < 0.01). Vitis sylvestris Gmelin has high antioxidant content when considering the data obtained. Also, we determined that it is an effective candidate in the protection against reactive oxygen species.

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  AtıfScopus2·OpenAlex3

  İncele
• MakaleAçık Erişim2018/r/munzur/3476
  Investigation of mineral components and antioxidant properties of a healthy red fruit: Cornelian Cherry (Cornus mas L.)

  Karaaslan, Merve Goksin; Karaaslan, Nagihan M.; Ates, Burhan

  The mineral components of the foodstuff consumed by an individual are important in the growth and development of a human being. In recent years red fruits, because of their potential beneficial health effects, are getting attention of both consumers and manufacturers. One of the red fruits, Cornelian cherry (Cornus mas L.), was investigated in terms of both mineral components and antioxidant properties. The mineral components include calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), and zinc (Zn) in this fruit were determined using flame atomic absorption spectrometry (FAAS). The antioxidant activity tests were applied to the extracts obtained using different solvents to examine the antioxidant properties of this fruit. Statistical analysis indicated that while the best results were obtained from acetone extracts, the lowest results were obtained from water extracts for all antioxidant activity tests (p<0.05). The best average values for DPPH and ABTS radical scavenging capacity, reducing power, total phenolic content and total flavonoid content in acetone extracts were found to be 1053.72±38.12 mg TEAC/100 g FW and 2907.34±152.05 mg TEAC/100 g FW, 5894.99±251.05 mg TEAC/100 g FW, 2979.25±69.40 mg GAE/100 g FW and 255.75±14.92 mg QE/100 g FW, respectively.

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  AtıfScopus14·OpenAlex13·TR Dizin3

  İncele
• MakaleYalnız künye2017/r/munzur/5405
  Dietary Element Assessment of Legumes Originated from Tunceli Province Using Different Dissolving Techniques

  Karaaslan, Nagihan M

  The objective of this study was to compare the mineral contents of chickpeas and haricot beans using two different analytical digestion methods, including dry ashing and microwave digestion method. The levels of micronutrients (Cu, Fe, Mn, and Zn) and macronutrient minerals (Ca, Mg, Na, and K) in two different legumes, as chickpea samples (Cicer arientinum L) and haricot bean (Phaseolus vulgaris L.) that are widely growing and consumed in Tunceli Province-Turkey were evaluated. The mineral composition of chickpea and haricot bean were determined by using FAAS after dissolving dry ashing and microwave digestion methods. In this way, both the mineral composition of legume samples and the dissolving methods were compared. Results obtained from each group and each method was analyzed statistically using the SPSS statistics program package. It was observed in chickpea and haricot bean samples that Ca, Cu, and Zn concentrations using microwave digestion method were higher than that of dry ashing method (p<0.01)

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