Yazarlar
- Duran, Celal(26)
- Ozdes, Duygu(21)
- Baltaci, Cemalettin(10)
- Gundogdu, Ali(10)
- Gül, Abdulkadir(9)
- Çullu, Mustafa(8)
- Aksüt, Yavuz Selim(7)
- Baltacı, Cemalettin(7)
- Barut, Abdulkadir(7)
- Bozbeyoglu, Pinar(7)
- Erol, Ismail(7)
- Ozeken, Sengul Tugba(7)
- Peker, Iskender(7)
- Eker, Hasan(6)
- Külekçi, Gökhan(6)
- Altuner, Elif Esra(5)
- Ar, Ilker Murat(5)
- Güzel, Melih(5)
- Karahan, Selim(5)
- Karpuz, Ömer(5)
- Kıranşan, Murat(5)
- Odabaş, Halil İbrahim(5)
- Seferoğlu, Mehmet Tevfik(5)
- Uysal, Turan(5)
- Demir Şahin, Demet(4)
- Imamoglu, Mustafa(4)
- Karpuz, Omer(4)
- Top, Yener(4)
- Akar, Bülent(3)
- Akpinar, Muhammet Vefa(3)
- Akpınar, Özlem(3)
- Avci, Ibrahim(3)
- Aydoğmuş, Ercan(3)
- Bozbeyoğlu, Pınar(3)
- Cakir, Mehmet Ali(3)
- Camoglu, Aslihan Yilmaz(3)
- Cavusoglu, Ibrahim(3)
- Daulay, Amru(3)
- Ercikdi, Bayram(3)
- Komut, Osman(3)
Yayınlar
- MakaleAçık Erişim2025Production and quality assessment of functional crackers based on fruit seed oils
Barut, Yeliz Tekgul; Koç, Gulsah Caliskan; Akdogan, Arda; Erdogan, Selma Lubabe; Ergün, Ahsen Rayman; Altay, Kadriye; Rustagi, Sarvesh; Ramniwas, Seema; Pandiselvam, Ravi
Crackers are popular bakery products known for their crunchy texture and long shelf life. Typically made from leavened or unleavened dough with wheat flour, oil, water, and additives, crackers have undergone recipe enhancements to improve sensory and nutritional profiles. While many studies explore cracker and biscuit formulations, fruit seed oils remain underexplored. Fruit seeds, often discarded as waste, are rich in essential fatty acids, amino acids, and micronutrients. Oils from seeds such as grape, pomegranate, rosehip, and apricot have gained attention for their health benefits, which presents an opportunity for innovation in bakery products. This study evaluated the potential of incorporating various fruit seed oils (pomegranate, apricot kernel, grape, fig, and rosehip) into cracker formulations. Crackers were assessed for physicochemical properties, antioxidant activity, mineral content, texture, and sensory attributes, with sunflower oil as the control. Results showed that the addition of fruit seed oils significantly influenced cracker properties. Crackers with apricot kernel oil had the highest ash content (2.29 +/- 0.13%) and exhibited a more acidic character, as did those with grape seed oil. Moisture content decreased significantly when rosehip seed oil was used (P < 0.05). Grape seed oil yielded the highest water-holding capacity, while sunflower oil provided the highest oil-holding capacity. Crackers made with rosehip and apricot kernel oils demonstrated improved antioxidant properties. Using fruit seed oils not only enhances nutritional value (e.g. vitamins, minerals, antioxidants, and dietary fiber) but also reduces material waste, contributing to sustainability and better resource utilization.
- MakaleAçık Erişim2025Greening the OECD: Unravelling the Complex Relationship Between Natural Resource Efficiency, Technological Innovation and Population Density on Ecological Footprint
Çabas, Meral; Beser, Nazife Ozge; Ayaydin, Hasan; Barut, Abdulkadir; Magazzino, Cosimo
This paper aims to investigate the relationship among green environmental technologies, resource efficiency, population density and ecological footprint in 38 OECD member countries between 2000 and 2019. The Method of Moments Quantile Regression (MMQREG) and Augmented Mean Group (AMG) estimators are used to analyse this relationship. Based on the results, strong evidence of a negative relationship between green environmental technologies, resource efficiency, population density and ecological footprint emerges, suggesting that these factors contribute to environmental improvement in OECD economies. Overall, the findings contribute to a deeper understanding of the complex dynamics among these variables and provide valuable insights for policymakers and stakeholders striving for sustainable environmental management and policy formulation. In this context, countries should develop standard guidelines and best practices on green technologies and resource efficiency, making it easier for sectors to adapt in these areas.
- MakaleAçık Erişim2025FinTech driven green energy transition foreign direct investment and ecological footprint in BRICST countries
Ayaydin, Hasan; Ergün, Tolga; Barut, Abdulkadir; Erdem, Azad; Pilatin, Abdulmuttalip
The increasing emphasis on climate change and environmental sustainability worldwide has brought about the convergence and increased focus on financial technologies (FinTech) and green energy initiatives. In light of this, the study's objective is to investigate how FinTech moderates the relationship between the ecological footprint (EF) and green energy transition (GTE) in the BRICS-T nations between 1990 and 2021. This study examines how fintech moderated the GTE and EF in the BRICS-T from 1990 to 2021. We applied the Fully Modified Ordinary Least Squares (FMOLS) and used Dynamic Ordinary Least Squares (DOLS) as the main estimators for longitudinal analysis. In contrast, Driscoll-Kraay was used to verify the robustness of the results under cross-sectional dependence and heteroskedasticity. The results reveal that FinTech indirectly hinders EF by facilitating GTE. The outcomes also show that FinTech significantly constrains EF, while GDP and industrialization worsen EF. The results also confirm the important role of GTE and foreign direct investment (FDI) in reducing CO2 emissions in BRICS-T countries. Lastly, the paper offers policymakers useful recommendations for lowering EF in light of these outcomes. The study suggests establishing appropriate policies and strategies that encourage FinTech platforms to invest in green energy projects, including financial technology, promoting energy-efficient and low-carbon foreign direct investment, and encouraging GTE.
- MakaleAçık Erişim2024Sustainability and Green Finance: Banking System in Turkey
Özbek, Adem
Today, one of the main factors that increases the importance of sustainability and green finance is the scarcity of resources that meet needs. Sustainability has important benefits in reducing environmental erosion, such as acting as a carrier for the transportation of existing resources to future generations. Green finance is the use of financial resources in projects that embrace climate change aspects in the creation of a sustainable environment. At this point, banks, which are at the center of the financial system, are at a key point in terms of both maintaining sustainability and directing economic resources to the right areas. In the study, existing sustainability and green finance legislation studies in Turkey were followed. In addition, an attempt has been made to compile the studies carried out by banks operating in Turkey on sustainability and green finance. As a result of the study, it was seen that significant regulations were not made in credit policies in the banking system in Turkey, especially in terms of reducing environmental pollution. At the same time, it is seen that public banks include more sustainability and green financing in their policies than private and foreign capital banks.
- MakaleAçık Erişim2024Çevresel Tehlikelerin Belirlenmesi ve Sağlık Etkilerinin İncelenmesi: Gümüşhane Katı Atık Tesisi Örneği
Güvendi, Aslıhan; Külekçi, Gökhan
Bu çalışmada, Gümüşhane ilindeki katı atık tesisinin iş sağlığı ve güvenliği Elmeri yöntemi kullanılarak incelenmiştir. Katı atık yönetim süreci, atık toplama, taşıma, ayrıştırma, geri dönüşüm ve bertaraf gibi adımları içermektedir. Bu süreçlerde potansiyel olarak ortaya çıkabilecek; atık toplama sürecinde, keskin kenarlı ve delici maddelerin bulunmasıyla oluşabilecek kesilmeler ve delinmeler, atıkların taşınması sırasında ağır yüklerin kaldırılmasıyla ilgili bel ve sırt yaralanmaları, ayrıştırma işlemi sırasında kimyasal maddelerin sızması veya bu maddelerin solunmasıyla ilgili zehirlenme veya solunum yolu rahatsızlıkları, geri dönüşüm sürecinde kullanılan makinelerin veya ekipmanların yanlış kullanımıyla ilgili kırılma, ezilme veya yakma gibi kazalar, atıkların bertaraf edilmesi sırasında oluşabilecek patlama veya yangın riskleri gibi tehlikeler mevcuttur. Bu tehlikeler, Elmeri yöntemi kullanılarak tanımlanmış, çalışanların ve çevrenin bu tehlikelere maruz kalma düzeyi değerlendirilmiş ve ortaya çıkan riskler belirlenmiştir. Elde edilen sonuçlar, tesis yöneticileri ve ilgili paydaşlar için önemli bir kaynak olabilir ve katı atık yönetiminde daha etkili önlemlerin alınmasına yardımcı olabilir. Bu çalışma kapsamında Elmeri yönteminde belirtilen 7 ana başlık altında toplanan metotlara göre çalışma alanlarında toplam 494 adet gözlem yapılmıştır. Yapılan gözlemlerden 239 tanesi doğru güvenlik davranışı ve durumları belirtirken 255 tanesi yanlış güvenlik davranış ve durumlarını belirtmektedir. Gözlem sonuçlarına göre çalışma alanlarındaki en yüksek mevcut güvenlik endeksi % 57,2 ile atık toplama gündüz vardiyası, en düşük indeks ise % 29,3 ile atık ayrıştırma kısmında hesaplanmıştır.
- MakaleAçık Erişim2024İnşaat Malzemesi Olarak Kullanılan Beton Örneklerinde Uçucu Külün Radyasyon Koruma Etkinliği Üzerindeki Etkilerinin EGS4 Kodu Kullanılarak Hesaplanması
Esra, Yilmaz Bayrak
Bu çalışmanın temel amacı, inşaat malzemesi olarak kullanılan beton örneklerinde çimentonun azaltılarak ve yerine uçucu kül kullanılmasının radyasyon koruma etkinliği üzerindeki etkilerini belirlemektir. Beton örneklerinin radyasyon koruma etkinliği, EGS4 kodu kullanılarak hesaplanmış ve teorik olarak XCOM verileri ile karşılaştırılarak tartışılmıştır. 59.5 ile 1332 keV arasındaki gama ışını enerji aralığında, uçucu kül ile karıştırılmış beton örneklerinin kütle soğurma katsayıları (μ/ρ), teorik olarak incelenmiştir; bu inceleme WinXcom ve EGS4 simülasyonlarıyla gerçekleştirilmiştir. Hesaplanan kütle soğurma katsayıları kullanılarak ortalama serbest yol (MFP), yarı değer tabakası (HVL), radyasyon koruma etkinliği (RPE), etkili atom numarası (Zeff) ve gama ışını kerma katsayıları (kγ) gibi çeşitli koruma parametreleri belirlenmiştir. İnşaat malzemesi olarak kullanıldığında betonun bileşiminde çimentonun azaltılması ve uçucu kül eklenmesinin, radyasyon koruma etkinliği üzerinde etkileyici değişikliklere yol açtığı gözlemlenmiştir.
- MakaleAçık Erişim2024Biogenic 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.
- MakaleAçık Erişim2024Sakkarozun Enzimatik Olarak Hidrolizinin Optimizasyonu
Gül, A.Kadir; Tanyıldızı, Muhammet Şaban
Nişasta kaynaklı glukoz şurupları endüstriyel uygulamalarda geniş bir paya sahip olmasına rağmen temelde sağlıkla ilgili tartışmalar tüketicilerde sakkarozun kullanımını öne çıkarmaktadır. Sakkaroz, asitleştirme veya enzimatik yöntemlerle invert şekerler adı verilen glukoz ve fruktoz monomerlerine hidroliz edilebilirler. Bu yöntemlerden enzimatik hidroliz işlemi geleneksel kimyasal proseslere göre daha düşük sıcaklıklarda gerçekleşmesi ve daha az toksik atık üretmesinden dolayı endüstride tercih edilen bir yöntemdir. Bununla birlikte, hidroliz işleminde kullanılan enzimler genellikle yeniden kullanımı zor ve stabilitesi düşük moleküller olup, üretim maliyetlerinin yüksek olması endüstriyel ölçekte uygulanmasını zorlaştırmaktadır. Bu çalışmanın amacı sakkarozun invertaz enzimi yardımıyla hidrolizinde önemli olan bağımsız değişkenlerin sakkaroz dönüşüm oranı, hidrolizi verimi ve toplam indirgen şeker konsantrasyonu üzerine etkisinin Merkez Kompozit Dizayn (MKD) deneysel tasarım yöntemi kullanılarak detaylı olarak belirlenmesidir. MKD ile gerçekleştirilen deneylerde incelenen bağımsız değişkenler ve cevap değişkenleri arasında enzim aktivitesini de içeren model bir denklem oluşturulmuştur. Bağımsız değişkenlerin incelenen aralıkları içerisinde, matematiksel model ifadenin hem indirgen şeker konsantrasyonu hem de dönüşümün maksimum olduğu şartlar için yapılan optimizasyon işlemi sonucunda; sakkaroz konsantrasyonu 190,16 g/L, enzim aktivitesi 55,36 U/mL, sıcaklık 33,46 oC, reaksiyon süresi 131,10 dk ve karıştırma hızı 120,86 rpm olarak belirlenmiştir. Sonuç olarak, sakkarozun enzimatik hidrolizi için verimli çalışma koşulları belirlenmiştir.
- Derleme MakaleAçık Erişim2024Production of 5-Hydroxymethylfurfural from Non-edible Lignocellulosic Food Wastes
Muslu, Ayşe; Üçüncü, Osman; Baltacı, Cemalettin
The compound 5-(hydroxymethyl)furfural (HMF) has emerged as a versatile intermediate with the ability to undergo conversion into both fuel and a variety of platform chemicals. Lignocellulosic biomass, such as hazelnut shells and tea processing residues, was employed in this study for HMF production through two distinct methods. In the first method, cellulose from biomass was converted to sugars using a 4% acid solution, followed by catalytic conversion with NaCl/CrCl3.6H2O. After a 1-h reaction at 131 °C in a high-pressure system, HMF was obtained from tea processing waste and hazelnut shells with yields of 8.6% (82.3 mg/g) and 6.7% (66.7 mg/g), respectively. The second method involved LiCl/NaCl-doped N,N-dimethylacetamide (DMA) as an ionic solvent system for HMF production. After a 2-h reaction at 131 °C in the DMA-NaCl/[EMIM]Cl ionic solvent system, HMF was obtained from tea processing waste and hazelnut shell celluloses with yields of 5.7% (57.5 mg/g) and 3.1% (31.3 mg/g), respectively. This study contributes to the economic conversion of various food wastes into valuable chemicals, highlighting the potential of lignocellulosic biomass in sustainable chemical production.
- MakaleAçık Erişim2024Deep eutectic solvent as plasticizing agent for the zein based films
Yilmaz, Mustafa Tahsin; Kul, Ebubekir; Saricaoglu, Furkan Turker; Odabas, Halil Ibrahim; Taylan, Osman; Dertli, Enes
This study explores, the impacts of incorporating of deep eutectic solvent (DES) as plasticizer on the characteristics of zein films. Investigation focused on examining the mechanical, thermal, surface, and microstructural properties of zein films that were plasticized using DES. The findings of the study revealed that by adding DES to zein films, there was an observed improvement in transparency. Additionally, it was observed that up to a 20% addition of DES led to a reduction in water vapor permeability (WVP). However, beyond this level, the WVP increased as the surface hydrophobicity decreased. The films that were plasticized with DES showed higher tensile and burst strength values than control. However, there was a decrease in the elongation at break and burst distance, except for the film containing 30% DES. The addition of DES as plasticizer resulted in smoother surface morphology compared to the control, and all films revealed homogeneous and non-porous surface and cross-section microstructure. The films plasticized with DES displayed three different thermal degradation temperatures resulting in higher thermal stability. The FT-IR spectrum of films showed similar backbone structure including Amide I, II and III bands. However, 5% DES plasticized film showed different secondary structural peaks of Amide I band due to lower α-helix and higher β-sheet and random coil content. The findings of this investigation indicate that the employment of DES as plasticizer in biodegradable polymer films can yield enhanced mechanical and barrier characteristics compared to conventional plasticizers, thus demonstrating its potential for effective use.
- MakaleYalnız künye2024Adsorption of Azocarmine G dye on H2SO4-modified acacia sawdust
Duran, Celal; Ozeken, Sengul Tugba; Camoglu, Aslihan Yilmaz; Ozdes, Duygu
Presence of hazardous dyes in water cause considerable risks to the human health and environment due to their potential toxicity and ecological disruptions. Therefore, in the present research, to suggest an alternative method for the retention of toxic Azocarmine G (ACG) dye from aqueous media, natural and H2SO4-modified acacia sawdust were performed for the first time as low-cost and efficient adsorbents. Based on batch experiments, it was determined that the best conditions for the developed dye retention process were an initial pH of 2.0 and an equilibrium time of 240 min. Analysis of the data using both pseudo-first order and pseudo-second order kinetic models showed that the retention of ACG onto the adsorbents predominantly occurred through chemical adsorption. Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models were employed to provide insights into the interaction between the adsorbate and adsorbent and the mechanism of the adsorption process. Maximum monolayer adsorption capacities of natural and H2SO4-modified acacia sawdust were determined as 28.01 and 64.90 mg g-1, respectively by Langmuir isotherm model. Results of the study clearly indicated that the modification of acacia sawdust with H2SO4 leads to a substantial increase in the adsorption performance of anionic dyes.
- MakaleAçık Erişim2024Gluconic Acid Production by Using Recombinant Escherichia coli Waksman pqq+ Cells with a Novel Approach from Biomass Sources
Gül, Abdulkadir; Tanyıldızı, Muhammet Şaban
Gluconic acid (GA) is widely used in the pharmaceutical, food, detergent, textile, leather, and concrete industries. However, cost-effective and high-yield production of GA remains a challenge. Due to currently high raw material inputs of GA, various alternative carbohydrate sources are being investigated. Sucrose is one of the cost-effective biomass sources that can be used as feedstock. The most common industrial production of GA is based on wild-type bacteria and fungi, but there are many problems with this production. This study aimed to optimize the production of GA from glucose produced by hydrolysis of sucrose using recombinant E. coli Waksman (W) pqq+ strain. After sucrose was enzymatically hydrolyzed, significant medium components for GA production were determined as glucose, calcium carbonate (CaCO3), peptone, and ammonium phosphate ((NH4)3PO4) using Placket-Burman Design (PBD). Detailed optimization of the medium components that are significant in GA production was carried out using central composite design (CCD), and optimum values of the independent variables examined in maximum GA production (93.5 ± 2.95 g/L) were determined as glucose 95, CaCO3 25, peptone 2, and (NH4)3PO4 1.13 (g/L). Using results obtained in the Erlenmeyer experiments, GA production in the bioreactor was investigated by CCD. The maximum GA efficiency (3.20 ± 0.15 g/L. h) was obtained under conditions where the air supply rate was 10.82 L/min, stirring speed was 656.87 rpm, and CaCO3 concentration was 16.90 g/L. In conclusion, it has been shown that GA can be produced with a high yield with this novel approach using a recombinant strain for GA production from sucrose.
- MakaleAçık Erişim2024A different look at the environmental Kuznets curve from the perspective of environmental deterioration and economic policy uncertainty: evidence from fragile countries
Anwar, Ahsan; Barut, Abdulkadir; Pala, Fahrettin; Kilinc-Ata, Nurcan; Kaya, Emine; Lien, Duong Thi Quynh
Environmental degradation is one of the most significant issues that developing nations confront and needs to be resolved right away in order for them to achieve sustainable development. Government policies are crucial in this situation since emerging nations frequently struggle with the issue of policy ambiguity, which can result in environmental deterioration. In this context, this study investigates how policy uncertainty affects environmental degradation in the five fragile emerging economies known as the Fragile Five—Brazil, India, Indonesia, South Africa, and Turkey. Using data from 1996 to 2019, we estimate a Panel Quantile Regression analysis. The empirical findings indicate that economic policy uncertainty and technology innovation increases the environmental degradation whereas environmental degradation is slowed down by financial development and renewable energy consumption. Empirical evidence also confirms the presence of EKC hypothesis in fragile economies. Based on the findings, we suggest both a policy and an environmental framework for achieving sustainable development in fragile economies. Graphical Abstract: (Figure presented.)
- MakaleAçık Erişim2024Central composite design modelling and developing a method for removing sulphate from an alunitic kaolin ore
Erkan, İlker; Inal, Serkan; Alp, İbrahim
The main mineral in kaolin ore, kaolinite, is well-known for its many uses in the paint, paper, and ceramics industries. The necessity of getting pure kaolinite is discussed in this work, with an emphasis on the extraction of impurities from kaolin. Specifically, alunitic kaolin, which is common in northwest Turkey, has sulfur concentrations higher than 3 % SO3, which means that it can't be used for many industrial purposes. Leaching is a popular method for removing sulfur, especially when done directly and through pre-treatment techniques like roasting. High-temperature roasting, however, presents difficulties since it causes phase transformation on kaolinite to metakaolin and mullite and on alunite to alum. The temperature of phase transformation is important on high temperature studies which affects negatively the thixotropic qualities that are essential for the production of ceramics. This study introduces a novel approach by optimizing roasting conditions and employing a central composite design methodology for leaching. The optimal parameters for the roasting studies were determined to be 525 °C for 3 h. For leaching, the ideal conditions were identified using the leaching recovery equation, which specifies 0.195 M NaOH, 80 °C, 127 min, and a 2.55 % solid content. These characteristics were confirmed by follow-up experiments, which showed a change in SO42− concentration from 3.03 % to 2.97 %, along with some structural changes in the roasted sample. The subsequent leaching process resulted in a significant drop in SO42− concentration to 0.46 %. By highlighting the effectiveness of lower-temperature roasting and optimizing experimental methodology, this research presents a novel thermochemical method for sulfur removal in alunitic kaolin.
- MakaleAçık Erişim2024Promoting sustainability in developing Countries: A Machine Learning-based approach to understanding the relationship between green investment and environmental degradation
Ahmad Khan, Khatib; Khalid Anser, Muhammad; Pala, Fahrettin; Barut, Abdulkadir; Wasif Zafar, Muhammad
The main objective of this study is to examine the impact of green investment on environmental degradation in developing countries using machine learning-based estimation combined with robustness tests of static and dynamic panel data modeling techniques. The scope of this study covers 30 developing countries for 2009–2019. This study introduces a new index of environmental degradation that uses the entropy method and includes green gas emissions and deforestation. The study addresses trade openness, the quadratic shape of economic growth, and urbanization in the context of the Environmental Kuznets Curve Hypothesis (EKC) and the Ecological Modernization Theory (EMT), in addition to green investment. This study considers the kernel-based regularized least squares (KRLS) approach, the static panel technique Driscoll & Kraay standards error method, and a dynamic panel technique system generalized moment techniques. The empirical findings from the machine learning method show that green investment significantly reduces environmental degradation with a higher coefficient resulting from the static fixed effect estimation. The study also reveals that the main hypotheses, such as EKC and EMT, are confirmed by all estimation techniques. Based on the results, the study recommends that policymakers take pragmatic steps toward green investments and increase the financing of green energy initiatives to combat environmental degradation.
- MakaleAçık Erişim2024Characterization of cellulose produced by bacteria isolated from different vinegars
Güzel, Melih
Traditional vinegars are naturally produced from sugar- or starch-containing raw materials, through alcoholic fermentation followed by acetic fermentation. Fermentation is a spontaneous and complex process involving interactions between various microorganisms. In this study, we produced vinegar using traditional methods from six fruits: rosehip, pear, fig, wild pear, apple, and plum. Bacteria that produce bacterial cellulose (BC) were isolated from these vinegars and identified. In addition, we investigated the properties of BC produced from these bacteria. The strains isolated from vinegars were identified as Gluconobacter oxydans strain MG2022, Acetobacter tropicalis strain MG2022, Acetobacter fabarum strain MG2022, Komagataeibacter saccharivorans strain MG2022, K. saccharivorans strain EG2022, and Acetobacter lovaniensis strain OD2022. In total, 0.83–2.04 g/L BC was produced and the bacterial strain isolated from pear vinegar yielded the most BC. BC produced by the bacterial strain isolated from wild pear vinegar had the highest thermal stability and crystallinity (87.44 %). Overall, this study shows that different fruits contain different BC-producing bacteria in their natural flora and vinegars obtained from fruits can be used in BC production. Also, different BC-producing bacteria can be isolated from different vinegars, and BC produced by these bacteria might have different properties.
- MakaleAçık Erişim2024Bioethanol Production from Mulberry Molasses Waste with Ohmic-Assisted Hydrodistillation
Tunç, Merve Tuğçe; Genç, Berna; Karataş, Şeyda Merve
In this study, the fermentation process of bioethanol production conditions were optimized by response surface methodology. Mulberry molasses production waste was used as the only carbon source for yeast fermentation to produce bioethanol. Hydrodistillation (HD) and ohmic-assisted hydrodistillation (OAHD) methods were employed to concentrate the bioethanol. Fermentation time (48–168 h), waste matter rate (5–45%) and pH (5–7) were selected as independent variables. Alcohol concentration was treated as the response. Optimum fermentation conditions were determined as 96.894 h fermentation time, 45% waste ratio and pH 7. At these optimum conditions, alcohol concentration was determined as 3.77 ± 0.33%. While the distillate obtained in the HD method contained 22.50 ± 1.89% alcohol, it showed 27.72 ± 0.24% in the OAHD method. The energy consumption values for OAHD and HD was 2.92 ± 0.51 and 53.24 ± 1.74 Wh/mL bioethanol, respectively. Results of study showed that the OAHD could be a cost-effective and green method to distillation of bioethanol from mulberry molasses waste.
- MakaleAçık Erişim2024Characterization of biodegradable bi-layer films from thermoplastic starch and poly-l-lactic acid
Parlak, Mahmut Ekrem; Uzuner, Kubra; Ozdemir, Sebahat; Kirac Demirel, Fatma Tuba; Dundar, Ayse Neslihan; Sahin, Oya Irmak; Dagdelen, Adnan Fatih; Odabas, Halil Ibrahim; Saricaoglu, Furkan Turker
This study aimed to enhance the oxygen barrier properties of polylactic acid (PLA) film, a biodegradable packaging material with high oxygen permeability (OP). Bi-layer films were produced by coating thermoplastic starch (TPS) onto PLA films in various ratios while maintaining constant film thickness. The mechanical, optical, barrier, thermal, hydrophobicity, moisture sorption, and microstructural properties of the films were analyzed. Increasing the TPS ratio elevated moisture content (MC), water uptake, solubility, and opacity while enhancing UV barrier properties. TPS coating reduced tensile and burst strength but increased the burst deformation of the bi-layer films. Bi-layer film production resulted in a water vapor permeability increase of 59.26%–94.44% compared with neat PLA while decreasing OP by 2.52%–29.66%. The equilibrium moisture content (EMC) rose with higher TPS ratios, displaying type II isotherms. FTIR analysis indicated no chemical interactions between PLA and TPS. Increasing the TPS ratio decreased PLA crystallinity, supporting the mechanical and barrier properties of the bi-layer films. Neat and bi-layer films exhibited smooth, homogeneous surfaces, with a visible interface in the cross-section of the bi-layer films. In conclusion, TPS shows promise as an alternative to improve oxygen barrier properties in PLA films without adversely affecting other properties.
- Derleme MakaleAçık Erişim2024Aflatoxin Detoxification by Biosynthesized Iron Oxide Nanoparticles Using Green and Black Tea Extracts
Gedikli, Hasan; Akdogan, Arda; Karpuz, Omer; Akmese, Osman; Kobya, Havva N.; Baltaci, Cemalettin
Researchers have recently been interested in employing nanoparticles (NPs) obtained from herbal extracts through green synthesis for various applications. This study investigated the detoxification of aflatoxins, which are toxic substances produced by molds Aspergillus flavus and Aspergillus parasiticus. The present work examined the levels of aflatoxins in hazelnut and peanut puree. Turkish black tea extract (BTE), Turkish green tea extract (GTE), green synthesized black tea-based iron oxide nanoparticles (BTFeONPs), and green tea-based iron oxide nanoparticles (GTFeONPs) were produced for aflatoxin removal. Characterizations and various antioxidant and antimicrobial activities of the tea extracts and iron oxide nanoparticles (FeONPs) were investigated. The aflatoxin levels of hazelnut puree used for this study were 6.57 ± 0.06 µg/kg for aflatoxin B1 and 13.03 ± 0.16 µg/kg for total aflatoxin, whereas the aflatoxin levels of (AFLB1) peanut puree were 7.79 ± 0.15 µg/kg for AFLB1 and 15.21 ± 0.12 µg/kg for total aflatoxin. Using soluble BTE resulted in a 40 to 50% decrease in aflatoxin levels in hazelnut and peanut purees, while soluble GTE led to a 30 to 45% decrease. Meanwhile, using BTFeONPs and GTFeONPs resulted in a 33 to 48% and 40 to 50% decrease, respectively, in aflatoxin levels in hazelnut and peanut purees.
- MakaleYalnız künye2024Waste Heat and Mass Recovery from Boiler Exhaust Gases in a New Generation District Heating System: Energy and Exergy Analysis
Terhan, Meryem
The study performs energy and exergy analyses for each component such as boilers, buildings, distribution networks and heat exchangers of a new generation district heating system. Energy and exergy efficiencies are compared for all system components, and energy and exergy losses are presented using Sankey and Grassman diagrams. Three flue gas condensers with finned bundles are designed for different capacities of boilers that intend to recover water and heat from the waste flue gas in the district heating system due to high flue gas energy losses. Colburn-Hougen and one-dimensional finite difference methods are used to design the flue gas condensers with the MATLAB program. The exergy analysis showed that the exergy input to the system is lost by 4.52% from the distribution networks, 4.15% from all buildings and 2.18% from the flue gas. In the system, the energy and exergy efficiencies of the boilers are calculated to be 87.23% and 17.32%, respectively, and the heat loss from the flue gas is found to be 12%. The design results show that the values of mass convection coefficient (km) for all flue gas condensers decrease from 0.0706 at the inlet condensation zone to 0.0354 towards the outlet. The total condensation rate and condensation efficiency are found to be 86 kg/h and 60%, respectively, for the 2500 kW boiler.
