İlgi alanları

Sürdürülebilir Kalkınma Amaçları

• 5
• 5
• 3
• 2
• 2
• 1
• 1

• MakaleAçık Erişim2026/r/gumushane/19410
  The Triple Relationship between Biofuel Production, Carbon Emissions and Economic Growth in Türkiye Using Time Series Analysis: A policy proposal based on algae in biofuel production

  Akar, Bülent; Akar, Sonay

  Purpose: Study aims to determine the causality relationship between production of biofuel, carbon emissions and economic growth between 2005 and 2022 in Türkiye. Findings: The findings show that there is a unidirectional causality relationship from biofuel production to carbon emissions in Turkey. Meanwhile, GDP was not found to be associated with any variable. Limitations: Access to regular and uninterrupted data on biofuel production in Turkey covers the period between 2005 and 2022. Therefore, this period was selected as the start and end years of the research, and the frequency range of the research was limited to 18 years. Originality/Value: Minimising the negative environmental impacts of production is becoming increasingly important. Because the decline in global reserves of fossil fuels and the greenhouse gas emissions indicate that is unsustainable of dependence on these energy sources. Consequently, it is coming to the agenda biofuels which are both renewable and carbon neutral among alternative energy sources. Biofuels based on plant oil, hydrogen, bioethanol or biodiesel can provide an improvement against fossil carbon emissions compared to fossil fuels such as petrol. Furthermore, the compatibility of biofuels with existing engine technology has increased interest in these resources both in scientific circles and in industrial investment areas. Study, the biofuels which are of economic and ecological importance considered to make a unique contribution to the field as a current study examining the interaction between carbon emissions and economic growth.

  • 
  • 
  İncele
• MakaleAçık Erişim2026/r/gumushane/14204
  GREEN SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF IRON OXIDE NANOPARTICLES FROM ROBINIA PSEUDOACACIA L. FRUITS FOR DYE REMOVAL FROM AQUEOUS SOLUTIONS

  Demir, Semra; Akar, Bülent; Baltaci, Cemalettin

  In this study, iron oxide nanoparticles were produced and characterized using a green synthesis method with Robinia pseudoacacia fruits. The structural and functional properties of the nanoparticles were investigated using XRD, TEM/EDX, and FTIR analyses. The results indicated that the produced iron oxide nanoparticles had nanoscale particle sizes and exhibited a poorly crystalline (predominantly amorphous) structure according to XRD analysis. The comparative adsorption performance of the synthesized FeONPs and fruit powder in the removal of malachite green (MG), phenol red (PR) and methylene blue (MB) from aqueous solutions was evaluated. According to the results, the adsorption capacity followed the order MB> MG > PR. FeONPs exhibited consistently higher Qₑ values across all dye systems compared to the fruit powder. High removal efficiencies were obtained at low and moderate initial concentrations, while increasing the adsorbent dose enhanced the overall removal but resulted in a reduction in the adsorption capacity per unit mass. The obtained findings indicate that biosynthesized iron oxide nanoparticles can be used as an efficient and environmentally friendly adsorbent for eliminating environmental pollutants.

  • 
  • 
  İncele
• MakaleYayıncıda açık erişim2026/r/gumushane/13686
  New Records for the Algal Flora of Türkiye from Blanket Bogs of the Eastern Black Sea Region

  Akar, Bülent; Avci, Utku

  Blanket bogs are ombrotrophic peatlands where water is mainly supplied by precipitation. This study reports new algal records from blanket bogs in Türkiye, contributing to the knowledge of Türkiye’s freshwater algal flora. Algal samples were collected from five different blanket bogs located in the Eastern Black Sea Region of Türkiye. Samples were obtained on a monthly basis during selected months, May, July, and September in 2021, May and September in 2022, and July in 2023. A total of 50 taxa belonging to 19 genera were identified: Scytonema (1), Cavinula (1), Kobayasiella (1), Netrium (4), Closterium (3), Actinotaenium (5), Cosmarium (3), Euastrum (3), Micrasterias (2), Spondylosium (1), Staurastrum (15), Staurodesmus (2), Tetmemorus (2), Microspora (1), Characium (1), Desmodesmus (1), Trachelomonas (2), Calycimonas (1), and Opisthoaulax (1). Calycimonas and Opisthoaulax are reported as new genera for the freshwater algal flora of Türkiye. The identified taxa were predominantly observed in acidic, oligotrophic and low-conductivity waters, thereby indicating the distinctive ecological characteristics and conservation value of alpine blanket peat bogs.

  • 
  İncele
• MakaleAçık Erişim2025/r/gumushane/12487
  DYE REMOVAL PERFORMANCE AND BIOLOGICAL ACTIVITIES OF IRON OXIDE NANOPARTICLES SYNTHESIZED FROM Cotoneaster sp. FRUIT EXTRACT

  Akar, Bülent; Baltacı, Cemalettin; Düzgün, Azer Özad; Karpuz, Omer; Karakullukçu, Volkan; Erdoğdu, Esma Gülbahar

  This work aimed to study the antioxidant, antibacterial, and dye adsorption capabilities of the aqueous extract of Cotoneaster sp. fruits (CFE) and iron oxide nanoparticles (CF-FeONP) green-synthesized from the CFE. CF-FeONPs were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses. The antioxidant activity of CFE and CF-FeONPs was assessed through various tests, including ABTS radical scavenging activity, DPPH radical scavenging activity, iron-reducing antioxidant power (FRAP), total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant content (TAC). The CF-FeONPs had superior antibacterial and antioxidant activity compared to the CFEs. Furthermore, CF-FeONPs suppressed the growth of Gram-negative bacteria such as Yersinia pseudotuberculosis ATCC 911, Escherichia coli ATCC 25922, Proteus vulgaris ATCC 13315, and Pseudomonas aeruginosa ATCC 43288, as well as by Gram-positive bacteria like Streptococcus pyogenes ATCC 19615, Staphylococcus aureus ATCC 25923. and Bacillus subtilis ATCC 6633. The microdilution medium technique was used to determine the minimum inhibitory concentration (MIC) of CFE and CF-FeONPs against these bacteria strains. The adsorption rates of CF-FeONPs exhibited variability based on the quantity of adsorbent used and the specific dye type, whereas the lowest adsorption rate was 250 mg/L. CF-FeONPs demonstrated higher adsorption capacities for malachite green (MG) dye compared to methylene blue (MB) and phenol red (PR).

  • 
  İncele
• MakaleAçık Erişim2025/r/gumushane/11764
  MODELING THE KINETICS OF HYDROXYMETHYLFURFURAL (HMF) FORMATION IN POMEGRANATE SOUR PRODUCED BY DIFFERENT EVAPORATION METHODS

  Erdoğdu, Esma Gülbahar; Akar, Bülent; Baltacı, Cemalettin

  Pomegranate sour is a traditional functional food that is widely consumed in Türkiye. The aim of this study is to determine the most convenient evaporation method to keep the amount of HMF, a carcinogenic substance formed as a result of high temperatures in the production of pomegranate sour, at low levels. The pomegranate sours were produced using five different evaporation methods (atmospheric pressure (AP), freeze-drying (FD), open air (OA), vacuum assisted (VA) and fan assisted (FA)) and the amount of HMF formed during the process was determined. Kinetic calculations showed that VA and FA methods followed first-order reaction kinetics at 60, 70 and 80 °C, while OA, FD and AP methods followed zero-order reaction kinetics at 80, 90 and 100 °C. The mean Q10 value was 1.0006, while the activation energy (Ea) ranged from 72.56 to 126.38 kJ/mol. It was found that the amount of HMF formed varied according to the method, temperature and production time and that the reaction rates increased with increasing temperature, especially for the OA method. In addition, pH, titratable acidity, invert and total sugar content, color, Brix and browning index were analyzed and a kinetic model including all these factors was developed.

  • 
  İncele
• MakaleAçık Erişim2024/r/gumushane/10356
  Diatom Communities in the Littoral Sediments of the Robert Island's Lakes, South Shetland Islands, Antarctica

  Akar, Bulent; Güney, Aysegul; Özkan, Korhan; Avci, Utku; Kandemir, Raif

  The study area is situated at Robert Island, which is located in the South Shetland Islands in the northwest of the Antarctic Peninsula. The diatom samples were taken as part of the Turkish Antarctic Expedition (TAE-II) which took place between March and April 2018. The samples were collected from the surface of sediments (c. 5 cm) at a depth of approximately 20 cm, 50-100 cm from the littoral zones of an inland glacial lake (L1) and three coastal lakes (L2, L3 and L4) situated on glacier-free area on Robert Island. The main objective of this study was to reveal the diversity and the abundance of diatom communities in the littoral sediments of the lakes on Robert Island. The lakes were shallow and oligotrophic freshwater lakes, although the coastal lagoons had a high conductivity and nutrient concentration. Twenty-six diatom taxa belonging to Achnanthes (1), Fragilaria (1), Frustulia (1), Gomphonema (1), Halamphora (1), Hantzschia (1), Hippodonta (1), Humidophila (2), Luticola (3), Melosira (1), Nitzschia (4), Pinnularia (3), Planothidium (2), Psammothidium (2), Stauroneis (1) and Stephanopterobia (1) were identified in the samples from these lakes. The coastal lake L2 showed the highest richness of diatom communities among the in studied lakes, with 21 identified taxa.

  • 
  İncele
• MakaleAçık Erişim2024/r/gumushane/19955
  Biogenic Iron Oxide Nanoparticles Based on Algal Biofilm Formed in the Wastewater Treatment Plant and Their Dye Removal Performance

  Baltaci, Cemalettin; Akar, Bülent; Karpuz, Omer; Demirel, İlyas Taner; Gülbahar, Esma

  In the field of environmental pollution removal, bioremediation plays a crucial role in removing or converting toxic substances from the environment. Bacteria, yeasts, molds, algae, and plants are widely used in bioremediation events. Recently, green-synthesized nanoparticles have also been employed in bioremediation applications. In this study, iron oxide nanoparticles (FeONPs) were synthesized from algal biofilms that are naturally formed in the settling ponds of the Gümüşhane Municipality Wastewater Treatment Plant. These biological nanoparticles were utilized to investigate their adsorption efficiency for water-polluting dyes such as methylene blue (MB), malachite green (MG), and phenol red (PR). The synthesized FeONPs were characterized using Fourier transform infrared spectroscopy (FTIR) scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD). To test their efficacy, MB, MG, and PR dye solutions were treated with 5.0, 10.0, and 20 g/L FeONP concentrations. The remaining dye concentrations were quantified with a UV-VIS spectrophotometer after filtration. The results showed that FeONPs obtained from algal biofilms effectively removed MB, MG, and PR, with the highest efficiency observed for PR.

  • 
  • 
  İncele
• MakaleAçık Erişim2023/r/gumushane/20379
  Physicochemical Analysis of Pomegranate Sours Produced by Traditional Method in Türkiye and The Investigation of Antioxidant Properties

  Baltaci, Cemalettin; Akar, Bülent; Oğuz, Miraç

  In this study, the physicochemical properties and antioxidant activities of the commercially produced 15 pomegranate sour samples and one control sample were determined and their compliance with the TS 12720 (traditional sour pomegranate concentrate standard) was evaluated. Antioxidant activity values of pomegranate sours extracts were determined using 6 different methods. The samples had strong antioxidant capacity, except for N10 and N15. In addition, glucose, fructose, sucrose, HMF and acidity measurements of the same samples did not show compatibility with TS 12720. The pH values of the samples of N7, N8, N10, N11, N14 and N15 were not in accordance with the standard values (2.4-4.0) The titratable acidity values measured in samples of N1, N3, N4, N6, N10, N13, N15 were below the value (>6.0% (m/m)) in the standard. While the brix values of the samples were measured between 59.20-75.70, the brix values of the N12, N13 and N14 samples were determined below the standard brix value (>68%). The highest HMF value of the samples were determined as 8117.66. According to TSE 12720, the HMF content should be not exceed 50 mg/kg. However, the HMF values of the samples were detected above the maximum limit value except for N8 and N16.

  • 
  İncele
• MakaleAçık Erişim2023/r/gumushane/20244
  Characterization, Antioxidant and Antimicrobial Activities of Iron Nanoparticles Synthesized Using Firethorn Fruit (Pyracantha coccinea Roemer) Extracts

  Düzgün, Azer Özad; Baltaci, Cemalettin; Akar, Bülent; Karakullukçu, Volkan; Karpuz, Omer

  The main focus of this study was to explore the biological activity of metal nanoparticles that were green-synthesized from firethorn fruits. Specifically, iron nanoparticles (Fe-NP) were synthesized from extracts obtained from fruits and seeds of the firethorn plant (Pyracantha coccinea) grown on Gumushane University’s campus for landscaping purposes. The antioxidant and antimicrobial properties of both extracts and synthesized iron nanoparticles were evaluated. To characterize the Fe-NPs, FT-IR spectroscopy, scanning electron microscopy (SEM), and X-Ray Diffraction (XRD) analyses were performed. The antioxidant activity of the fruit extracts and Fe-NPs was assessed using various antioxidant activity tests, including ABTS radical scavenging activity, DPPH radical scavenging activity, ferric reducing antioxidant power (FRAP), total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant content (TAC). The results of all antioxidant activity tests indicated that the iron nanoparticles exhibited higher antioxidant activity than the fruit extracts. Moreover, the minimum inhibitory concentrations (MIC) of the fruit extracts and nanoparticles against Gram-negative bacteria (Yersinia pseudotuberculosis ATCC 911, Escherichia coli ATCC 25922, Proteus vulgaris ATCC 13315, and Pseudomonas aeruginosa ATCC 43288) and Gram-positive bacteria (Streptococcus pyogenes ATCC 19615, Staphylococcus aureus ATCC 25923, and Bacillus subtilis ATCC 6633) were determined the using the medium microdilution procedure. Similar to the antioxidant activity findings, the Fe-NPs demonstrated stronger antimicrobial activity compared to the fruit extracts.

  • 
  • 
  İncele
• MakaleAçık Erişim2022/r/gumushane/17205
  Determination of physical, chemical and antioxidant properties of pomegranate sauces sold in Turkish markets

  Baltaci, Cemalettin; Akar, Bülent; Kamış, Yunus Emre

  This study aimed to determine the physical, chemical and antioxidant properties of pomegranate sauces sold in the Turkish markets. A total of eighteen pomegranate sauces, seventeen of which were purchased from the market, and one produced in a rotary evaporator, were analyzed with respect to antioxidant activity, titratable acidity, brix, hydroxymethylfurfural (HMF), pH, color, and sugar. The antioxidant activities of the samples were analyzed by six different methods, including DPPH (2,2-diphenyl-1-picrylhydrazil) radical scavenging activity, ferric reducing antioxidant power (FRAP), ABTS●+ radical scavenging capacity, total antioxidant capacity assay (TAC), total phenolic content (TPC), and total flavonoid content (TFC) methods. The highest and lowest antioxidant activity values were as follows, respectively: 5.23 and 822.69 mg AA/kg for the DPPH method, 57.94 and 2380.94 mg FeSO4/kg for the FRAP method, 660.47 and 3690.83 mg AA/kg for the TAC method, 23.06 and 11680.71 mg QEE/kg for the TFC method, and 123.54 and 9566.95 mg GAE/kg for the TPC method. In addition, HMF contents of the most samples were below the permissible limit value (50 mg/kg), while some of them showed a heterogeneous distribution between 4.58 and 103.68 mg/kg. Such a heterogeneous distribution of the HMF contents may be due to the factors such as raw materials and additives used in production, applied heat treatments, production processes, and storage conditions. As a result, HMF content in pomegranate sauce can be reduced below the permissible limit if the production conditions comply with the standards.

  • 
  İncele