06. Meslek Yüksekokulları

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Citation - WoS: 12
Citation - Scopus: 17
Acoustic-Driven Airflow Flame Extinguishing System Design and Analysis of Capabilities of Low Frequency in Different Fuels
(Springer, 2022) Taşpınar, Yavuz Selim; Köklü, Murat; Altın, Mustafa
Traditional fire extinguishing methods can harm people and nature. For this purpose, in this study, no harmful acoustic-driven airflow fire extinguishing system was developed and experiments were carried out to extinguish gasoline, kerosene, thinner (synthetic thinner) liquid fuels and liquid petroleum gas (LPG) flames. 17,442 extinguishing experiments were conducted in 5 different flame sizes, 54 different frequencies and 10 cm to 190 cm distance range. The data obtained were analyzed using the polynomial regression method. For liquid fuels, the frequencies of 10 Hz to 50 Hz at a distance of 10 cm to 100 cm, 10 Hz to 32 Hz at a distance of 100 cm to 150 cm, and 10 Hz to 28 Hz at a distance of 150 cm to 180 cm are effective extinguishing ranges. LPG fuel, 10 Hz to 45 Hz at a distance of 10 cm to 140 cm, frequencies of 15 Hz to 30 Hz at a distance of 140 cm to 180 cm are effective extinguishing ranges. In addition, caused by the compression of the woofers membrane inside the collimator and the injected airflow at frequency of 30 Hz reduced the 12 cm diameter metal plate from 86.2 degrees C to 18.8 degrees C in 5 min, and the metal plate left to cool down from 80 degrees C to 21.7 degrees C in 10 min at a distance of 100 cm. The average Mean Square Error value obtained as a result of polynomial regression analysis is 0.9544, and the Root Mean Square Error value is 1.2020.
Citation - WoS: 27
Citation - Scopus: 34
Analysis of Effect Factors on Thermoelectric Generator Using Taguchi Method
(ELSEVIER SCI LTD, 2020) Terzioğlu, Hakan
Due to technological developments in recent years, the need for domestic and industrial electric power is increasing day by day. Alternative energy resources have become more important to reduce production costs by converting waste energy into electricity. In this study, a research was carried out to increase the efficiency and on the factors which were effective in Thermoelectric Generators (TEG) used in the production of electrical energy by using thermal sources from alternative energy sources. In this study, the effects of heat transfer performance of the materials (copper, aluminum and brass) on which thermal water is carried, and the effects of water pressure and velocity on the performance of TEGs were investigated. Taguchi method was used to determine the performance effects in the most accurate way. Taguchi method used three levels with three factors: material (copper, aluminum and brass), engine speed (I, II and III) and water pressure (1-2.5-3.5 bar). In addition, in the Taguchi method, the orthogonal array was used and the optimum operation time was significantly reduced. In this study, TEG1-12706 and TEG1-12710 were performed in 2 different TEGs. 27 experiments were carried out for each TEG under different materials, speed and pressure of water with the experiment set up in this study. When the test results were analyzed by Taguchi method, it was determined that the material was the most important factor in determining the output power and efficiency in the production of electrical energy by using TEG (approx. 89%) and it was seen that the pressure and engine speed had almost no role. (C) 2019 Published by Elsevier Ltd.
Citation - WoS: 28
Citation - Scopus: 33
Comparison of Commercial and Traditional Kefir Microbiota Using Metagenomic Analysis
(WILEY, 2021) Biçer, Yusuf; Telli, Arife Ezgi; Sönmez, Gonca; Turkal, Gamze; Telli, Nihat; Uçar, Gürkan
The current study aimed to determine the bacterial microbiota of five commercial and one traditional kefir beverages consumed in Turkey. In all samples, Firmicutes (93.66%-99.98%) were the most abundant filum. Actinobacteria were detected (6.19%) in one commercial sample, and Proteobacteria were detected (5.91%) in the traditional kefir beverage. The dominant family in all commercial kefir beverages was Streptococcaceae (89.12-99.83%), and the most common genus was Lactococcus in three samples and Streptococcus in the other two samples. However, Lactobacillaceae (36.68%) and Streptococcaceae (36.68%) were dominant in traditional kefir. Lactococcus, Streptococcus and Enterococcus were common in all samples.
Citation - WoS: 20
Citation - Scopus: 18
Comparison of Different Optimization Based Land Reallocation Models
(ELSEVIER SCI LTD, 2020) Uyan, Mevlüt; Tongur, Vahit; Ertunç, Ela
Land reallocation, which is an optimization problem in the field of engineering, is the process of reallocating parcels to pre-determined blocks according to the preferences of landowners. In practice, this is done manually and takes weeks or even months. The elongation of this process affects both the cost of the project and the project's acceptability by the landowners and thus the success of the project. Because the success of land consolidation projects is determined by the satisfaction of the landowners. For these reasons, the optimization-based land reallocation studies have been extensively carried out recently. However, these methods in the literature are not used in practice and the reallocation is still done manually. Therefore, for the first time in this study, two new reallocation models were developed to solve this problem by using Migration Birds and Simulated Annealing Algorithms and the results of these methods in a real project area were compared. Additionally, the results were compared to the conventional reallocation method (manual reallocation) to evaluate the performance of the methods developed. Both proposed methods provided a successful and practicable reallocation plan in a very short time with respect to the conventional one.
Citation - WoS: 20
Citation - Scopus: 20
Comparison of Microbiota and Volatile Organic Compounds in Milk From Different Sheep Breeds
(Elsevier Inc., 2021) Yusuf, B.; Ezgi, T.A.; Gonca, S.; Telli, Nihat; Gürkan, U.
In this study, we compared the microbiota and volatile organic compounds (VOC) present in the milk obtained from 3 different sheep breeds, namely Merino, Lacaune, and Assaf. Udder milk was collected from 21 animals, 7 from each breed. Bacterial microflora was determined metagenomically by extracting the DNA from the milk and analyzing the V3-V4 region of the 16S rRNA gene. Headspace solid-phase microextraction gas chromatography-mass spectrometry method was used to analyze VOC. The metagenomic analysis revealed (for Merino, Lacaune, and Assaf milk, respectively) Firmicutes (66.32, 69.36, and 57.08%), Actinobacteria (19.09, 7.67, and 19.40%), Proteobacteria (13.76, 21.06, and 22.19%), and Bacteroidetes (0.84, 1.91, and 1.33%) phyla in the milk samples. Lactobacillus was highly abundant in the milk of 3 breeds (29.64, 43.50, and 18.70%). The genera constituting more than 2% of all bacteria in all groups were Jeotgalicoccus (7.19, 5.34, and 10.77%), Enterococcus (5.18, 9.78, and 3.64%), and Corynebacterium (4.08, 3.00, and 13.44%). A total of 32 different VOC were identified by headspace solid-phase microextration analysis with 9, 30, and 24 different compounds from Merino, Lacaune, and Assaf breeds, respectively. Although ketone was the most abundant compound in Merino milk (71.84%), hydrocarbons were the most detected in Lacaune and Assaf milk (37.18% and 55.42%, respectively). A positive correlation was found between acetone, which was detected at the highest level in all groups, with Salinicoccus, Alloiococcus, Psychrobacter, and Dietzia. In addition, a negative correlation was found between the Lactobacillus genus, detected at the highest level in all groups, with methyl cyclopentane, 3-methylheptane, octane, decane, 3,3-dimethyloctane, and dodecane. Thus, differences were observed in the bacterial microflora and VOC in the sheep milk from different breeds under different feeding and breeding conditions. © 2021 American Dairy Science Association
Citation - Scopus: 14
Determination and Modeling of Lignite Reserve Using Geostatistical Analysis and Gis
(SPRINGER HEIDELBERG, 2021) Uyan, Mevlüt; Dursun, Arif Emre
Thrace Basin is one of the most significant coalfields due to the lignite reservoir in Turkey. A coal deposit was chosen as the study area in the Thrace coal basin, which is tertiary within Oligocene geological formation. The purpose of this study is to produce modeling of coal seams in the study area and to create spatial distribution maps for estimation of lignite coal resource characteristics using geostatistical methods with Geographic Information System (GIS) technology. Spatial continuity of the coal depth data was forecasted with an empirical variogram. The performance of six different models has been compared for ordinary kriging separately for both skewed data and transformed data according to the presence and absence of the trend. Spatial structure of the coal depth data was better explained using circular models. The nugget-sill ratio was indicated high spatial dependency with 0.002 and 0.009 for upper-lower surfaces of coal seams respectively. The estimations obtained for coal depth data were represented in a map. In the study area modeled with ordinary kriging method, it was estimated that there was a 17,516,997 m(3) coal reserve as a result of the reserve calculation made with ArcGIS 10 software.
Citation - WoS: 13
Citation - Scopus: 15
Determination of Some Physical and Chemical Properties of Common Hawthorn (crataegus Monogyna Jacq. Var. Monogyna)
(SPRINGER, 2021) Dokumacı, Keziban Yalçın; Uslu, Nurhan; Hacıseferoğulları, Haydar; Örnek, M. Nevzat
Hawthorn as a wild plant is an important fruit for human health. In this study, it was aimed to determine some physical and chemical properties of common hawthorn which is native plant of middle Anatolia in Turkey. According to chemical analysis results, crude protein, crude oil, ash, pH, acidity, total phenol contents and antioxidant activity values were found to be 3.03%, 1.22%, 2.77%, 4.08, 1.56%, 9.35 mg g(-1) and 67.62% respectively. Some mineral matter contents as K, P, Ca, Mg, Fe, Na and B values were found to be 16,273.88 mg kg(-1), 1316.92 mg kg(-1), 1263.86 mg kg(-1), 934.87 mg kg(-1), 62.20 mg kg(-1), 57.06 mg kg(-1) and 42.28 mg kg(-1) respectively. The values of mass, diameter, length, geometric mean diameter and sphericity of Common hawthorn fruit were determined as 0.93 g, 11.37 mm, 12.25 mm, 11.65 mm and 0.95 at 68.98% (db) humidity respectively. In addition, fruit hardness, chroma (C*), hue angle (h*) of hawthorn was found as 1.21 N, 28.94 ve 16.19 under same humidity respectively. According to study results, it can be concluded that the hawthorn fruits are admirable natural food for human nutrition, and it can be considered as reference for the future researches.
Determination of Thermotolerant Campylobacter Spp. by Viability-Qpcr in a Poultry Slaughterhouse and in Retail
(Eugen Ulmer Gmbh Co, 2021) Telli, E.; Uçar, G.; Sönmez, G.; Telli, N.; Türkal, G.; Doğruer, Y.
This study aimed to evaluate the viability of thermotolerant Campylobacter spp. in chicken carcasses during the slaughter process (n = 150) and at retail level (n = 72). All samples were analysed by quantitative PCR (qPCR), propidium monoazide (PMA)-treated qPCR, and direct plate counting (DPC). The quantitative comparisons were performed for assessing viability and culturability according to the values of the samples that were found to be positive in all methods. Due to the underestimation of viable but unculturable (VBNC) or dead cells, PMA-untreated samples, either at different slaughter stages or at retail level, had a higher positivity and quantity rate (p < 0.05) than the PMA-treated and DPC samples. Across the slaughter line, the above mentioned three methods revealed the highest positivity and quantity level during the evisceration stage. After the water-chilling and storage phases, positivity and quantity rates were not comparable as PMA-qPCR and DPC failed to detect the level of contamination not only in terms of cultivability but also in terms of viability as a result of compromised membrane integrity at low temperatures. In conclusion, recording of Campylobacter spp. during the chicken slaughter process by PMA-treated qPCR would provide more realistic quantitative data for poultry meat contamination.
Citation - WoS: 15
Citation - Scopus: 15
Developing a Deep Neural Network Model for Predicting Carrots Volume
(SPRINGER, 2021) Örnek, Mustafa Nevzat; Örnek, Humar Kahramanlı
In this paper, a deep learning approach to predict carrots volume according to the physical properties was designed. A total of 464 carrots were used for volume prediction. The used carrots were taken from Kasinhani, Konya. First, the data was produced. For this, the length, the diameters with 5 cm intervals, and the volume of each carrot were measured and recorded. The measurements were done using a steel ruler, a vernier caliper, and a glass graduated cylinder. Two deep learning methods: DFN and LSTM were developed to predict carrot volume. The developed systems were implemented with the Keras library for Python. Statistical measures such as Root Mean Squared Error, Mean Absolute Error, and R-2 were used to determine the predicting accuracy of the system. Both methods produced very close values. DFN and LSTM networks achieved 0.9765 and 0.9766 R-2, respectively. RMSE values were 0.0312 for both models. The results obtained showed that both DFN and LSTM are successful and applicable to this task.
Citation - WoS: 1
Citation - Scopus: 1
An Easy-To Self-Healing Smart Design for Increasing Impact Strength and Crashworthiness Resistance of Honeycomb Sandwich Structures
(Sage Publications Ltd, 2022) Güçlü, Harun; Osmanoglu, Serhat; Hayırkuş, Aslıhan; Taş, Oğuzhan; Yazıcı, Murat
In this paper, the dynamic compression impact response of an aluminum honeycomb core filled with open-cell foams impregnated with self-healing liquid agents was investigated experimentally. Samples were subjected to a variety of impacts in order to determine healing time and self-healing performance. Three different sandwich specimens were developed to evaluate the effectiveness of self-healing. The sandwich specimens are designated as B (empty honeycomb core cells), S (only open-cell soft polyurethane foam-filled honeycomb core cells), and self-healing agent (SHA) (open-cell soft polyurethane foams impregnated with liquid self-healing agents). The test results were presented by considering the crashworthiness and healing efficiency criteria, and the impact characteristics of the samples were compared related to these criteria. After testing, the results demonstrated that the self-healing agent specimens had much fewer buckling deformation and displacement than their counterparts. Significant improvements were achieved in healing efficiencies and crashworthiness evaluation criteria. The peak load and the energy needed to attain peak load are considered healing efficiency criteria. Self-healing agent specimens reached 29.7% and 12.9% more peak loads, and in the energy absorbed up to peak loads 140% and 34.9% higher values than the B and S sandwiches. In the same samples, crushing strain features were acquired as 50% versus 66%, indicating less displacement in self-healing agent specimens than counterparts. The results indicated that an aluminum honeycomb sandwich structure that can heal itself after damage and recover impact characteristics remarkably could be produced practically.
The Effect of Cutting Direction and Water Based Varnish Type on Sound Absorption Coefficient in Some Native Wood Species
(2024) Muslu, Mustafa Selmani
Noise which could be defined as disturbing sound, is becoming a major problem depending with developing technology. Controlling the noise helps raising the quality of life to higher levels. Although the intensity of the noise is not at a level that will affect human health, it should be reduced or eliminated, for better life standart. Due to the adverse effects of the noise level on health; the acoustic properties of living areas require serious consideration. Sound absorption coefficients of the materials used in the interior play an important role in providing sensory comfort depending on the volume. Natural and artificial wood are commonly used materials in interior design, especially in the construction of partition elements. In addition, wood is natural material and it has some important advantages and disadvantages. In this study the sound absorption coefficients of eastern beech and scotch pine trees, which are the most preferred materials in in-terior design, were investigated. For this pupose, these wood materials were cut superficially and radially according to the intersection directions, then the sample surfaces were varnished with one and two component water-based varnishes that do not contain solvent-based resin. The sound absorption coefficients of the ob-tained samples were determined by the impedance tube method and the results were compared statistically. It has been investigated that the obtained results could be evaluated statistically within the frequency values, besides, different results could be obtained according to the characteristics of natural wood materials, the direc-tion of intersection and water-based varnish types. According to the findings obtained as a result of the study, it has been suggested that if natural wood material is used indoors, the superficial cross-section of East beech wood should be used according to the direction of intersection, and a two-component varnish should be used according to the varnish type.
Citation - WoS: 2
Citation - Scopus: 2
Effect of Encapsulated Propolis on Microbial Quality and Antioxidant Activity of Yoghurt
(Mattioli 1885, 2022) Günhan, Rabia Serpil; Keskin, Şaban; Telli, Nihat; Takma, Çiğdem; Kolaylı, Sevgi
Yoghurt, a functional food, has been gained much attention on its production and consumption in the world. It is a fermented dairy product that contains lots of nutritional components. Some manufacturers have used some additives to extend the shelf life of yoghurt. Propolis could be alternative food additive instead of synthetic ones. Propolis is a resinous mixture collected by honeybees for hive protection. In this study functional yoghurt fortified with microencapsulated propolis was prepared. Ethanol extract of propolis was encapsulated by using sodium alginate, pectin and gelatin separately. The effect of microencapsulated propolis on physicochemical characteristics and microbial quality of yoghurts was tested. Especially the effect of propolis on unwanted microorganisms during storage was studied. Our results clearly showed that fortified yoghurt samples were better in terms of microbial quality during storage. It could be concluded that propolis could be a natural preservative for extending the shelf life of yoghurt.
Citation - WoS: 13
Citation - Scopus: 13
Electrical Behaviors of the Co- and Ni-Based Poms Interlayered Schottky Photodetector Devices
(Wiley, 2022) Yıldırım, Murat; Kocyigit, Adem; Torlak, Yasemin; Yenel, Esma; Hussaini, Ali Akbar; Kuş, Mahmut
Polyoxometalates (POMs) are attractive materials for various applications such as energy storage, catalysis and medicine. Here, Co and Ni-based POMs are chemically synthesized and characterized by X-ray diffractometer (XRD) and Fourier transform infrared spectroscopies (FT-IR) for structural characterization. While the morphological behaviors are analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM), the optical properties are investigated by UV-Vis spectrometer. Electrochemical characterizations are carried out by cyclic voltammetry to determine oxidation levels of the metal centers in the POMs. The CoPOM and NiPOM are inserted in between the Al metal and p-Si semiconductor to obtain Al/CoPOM/p-Si and Al/NiPOM/p-Si Schottky-type photodetector devices. Current-voltage (I-V) and current-transient (I-t) measurements are employed to understand the electrical properties of the Al/CoPOM/p-Si and Al/NiPOM/p-Si devices under dark and various light power intensities. The devices exhibit phototransistor like I-V characteristics in forward biases due to having POMs active layers. Various device parameters are extracted from the I-V measurements and discussed in details. I-t measurements are performed to determine various detector parameters such as responsivity and specific detectivity values for under 2 V and zero biases. The Al/CoPOM/p-Si and Al/NiPOM/p-Si Schottky-type photodetector devices can be employed in optoelectronic applications.
Citation - WoS: 8
Citation - Scopus: 9
An Experimental Performance Comparison of Newtonian and Non-Newtonian Fluids on a Centrifugal Blood Pump
(Sage Publications Ltd, 2022) Önder, Ahmet; Yapıcı, Rafet; İncebay, Ömer
The use of substitute fluid with similar rheological properties instead of blood is important due to ethical concerns and high blood volume consumption in pump performance test before clinical applications. The performance of a centrifugal blood pump with hydrodynamic journal bearing is experimentally tested using Newtonian 40% aqueous glycerin solution (GS) and non-Newtonian aqueous xanthan gum solution of 600 ppm (XGS) as working fluids. Experiments are performed at four different rotational speeds which are 2700, 3000, 3300, and 3600 rpm; experiments using GS reach between 8.5% and 37.2% higher head curve than experiments using the XGS for every rotational speed. It was observed that as the rotational speed and flow rate increase, the head curve difference between GS and XGS decreases. This result can be attributed to the friction reduction effect when using XGS in experiments at high rotation speed and high flow rate. Moreover, due to different fluid viscosities, differences in hydraulic efficiency were observed for both fluids. This study reveals that the use of Newtonian fluids as working fluids is not sufficient to determine the actual performance of a blood pump, and the performance effects of non-Newtonian fluids are remarkably important in pump performance optimizations.
Citation - WoS: 13
Citation - Scopus: 16
The Fuzzy Logic-Based Modeling of a Micro-Scale Sloped Solar Chimney Power Plant
(KOREAN SOC MECHANICAL ENGINEERS, 2021) Güzel, Muhammed Hüseyin; Ünal Ercan, Hatice; Önder, Ahmet; Şen, Muhammed Arif; Köse, Faruk
The energy demand of world is increasing worldwide because of increasing population and developing technology. The use of environmentally friendly renewable resources is very important in providing the increasing energy needs. In the renewable energy sources, the solar energy has a strategic importance because of its huge potential and unlimited. The production of electrical energy by solar chimney power plants is one of the reliable and profitable methods. Fuzzy logic-based approaches are commonly used for modeling different systems in many fields. Also, a renewable energy system can be modelled by fuzzy definitions. In this way, it can provide efficiently and quickly theoretical estimates of systems with productive simulations. In this study, using the experimental data obtained from the micro-scale sloped solar chimney power plant in carried on scientific research project by authors, the obtaining and verifying a fuzzy logic-based model (FLBM) that can calculate the change in air velocity at turbine according to the change of radiation and temperature is presented. The air velocity at the turbine inlet is the considerable variable determining the electricity generation in a solar chimney. Thus, the output of the model is determined as this air velocity. In changes in the radiation and temperature values are defined as inputs. A two input-one output fuzzy model is obtained, in which the inference method is designed in the form of Mamdani and the membership functions in the form of the triangle, making inferences according to the rule base determined by the experience achieved from the experimentally studies. In order to investigate the accuracy of the FLBM, the simulation results and the data get from experimental setup in April 2019 are compared and evaluated. The validation of the FLBM compared to the experimental system is investigated using different error evaluation criteria. It is proved that the results of FLBM and experimental data are realized at a high rate (95.95 %) close to each other and similarly.
Citation - WoS: 6
Citation - Scopus: 7
Fuzzy-Based Modeling and Speed Optimization of a Centrifugal Blood Pump Using a Modified and Constrained Bees Algorithm
(Elsevier Ireland Ltd, 2022) İncebay, Ömer; Önder, Ahmet; Arif, Şen, Muhammed; Yapıcı, Rafet; Kalyoncu, Mete
Background and objective: Side effects that may occur when using blood pumps for treatment of patients are the main limitations on pump rotational speed determination. Efforts are being made to reduce side effects in both design and usage procedures. In determining the pump speed for treatment, decreasing the pressure on the main artery and preserving the valve functions are taken into consideration. In addition to these, the parameters considered for design which include pump efficiency and mechanical effects on blood cells, should also be taken into consideration. In this study, the aim is to obtain the optimum pump speed for the maximum hydraulic efficiency and minimum wall shear stresses that occur inside the pump. Methods: Blood pump modeling based on fuzzy logic is created on the hydraulic performance data of a centrifugal blood pump, whose design, CFD analysis, manufacture and experimental testing have been performed previously. Using this fuzzy logic model, the optimum pump speeds were determined using the Bees Algorithm, an intuitive optimization algorithm, in the operating range 1-7 L/min fluid flow rate. In the optimization process, the aim is to achieve minimum shear stress with maximal efficiency. Intravascular pressure limits (90-160 mm-Hg) were set as pressure constraints. Results: The optimum operating point is obtained as a 3350 rpm pump speed and a 4.35 L/min flow rate. At this operating point, CFD simulation is performed, and maximum wall shear stress was found to be 1458 Pa and its efficiency as 34.2%. Conclusions: In addition to the parameters commonly used in the pump speed optimization of blood pumps, the use of wall shear stresses and pump efficiency can provide certain improvements. © 2022
Citation - WoS: 21
Citation - Scopus: 22
Hplc-Dad Characterization of Phenolic Profile and in Vitro Antioxidant, Anticholinesterase, and Antidiabetic Activities of Five Mushroom Species From Turkey
(Springer Heidelberg, 2021) Çayan, Fatih; Tel-Çayan, Gülşen; Deveci, Ebru; Duru, Mehmet Emin
In this study, Daedalea quercina (L.) Pers., Hydnum repandum L., Inonotus radiatus (Sowerby) P. Karst., Omphalotus olearius (DC.) Singer, and Schizophyllum commune Fr. hexane and methanol extracts were subjected to the spectrophotometric assays for antioxidant and enzyme inhibitory activities, which are linked with human diseases that are very prevalent in recent years. Additionally, phenolic compounds of the mushrooms were quantified by HPLC-DAD. The best antioxidant activity was found in H. repandum methanol extract (IC50: 12.04 +/- 0.24 mu g/mL) in the beta -carotene-linoleic assay; I. radiatus methanol extract in DPPH center dot (81.22 +/- 0.50%), ABTS(center dot+) (IC50: 73.47 +/- 0.18 mu g/mL), and CUPRAC (A(0.50): 88.21 +/- 0.02 mu g/mL) assays; S. commune hexane extract (53.36 +/- 0.89%) in the metal chelating assay. O. olearius hexane extract was found as the best inhibitor against AChE (71.58 +/- 0.28%) and BChE (67.30 +/- 0.15%). When I. radiatus methanol (95.88 +/- 0.74%) and H. repandum hexane (95.75 +/- 0.16%) extracts showed close alpha -amylase inhibitory activity to acarbose (96.68 +/- 0.08%), D. quercina methanol extract (70.79 +/- 0.34%) had higher alpha -glucosidase inhibitory activity than acarbose (67.01 +/- 2.28%). Among 16 phenolic compounds analyzed, gallic acid (0.02 +/- 0.01-0.23 +/- 0.01 mu g/g) was detected in all studied mushrooms. This study provides that investigated mushrooms can be used for further research, which can lead to the development of new natural remedies to alleviate complications related to oxidative stress, diabetes, and neurological diseases.
Citation - WoS: 1
Citation - Scopus: 1
Investigation of Changes in Culturable Lactic Microflora During Freeze Storage in Cow and Goat Milk Kefirs by High-Throughput Sequencing
(Wiley, 2022) Biçer, Yusuf; Telli, A. Ezgi; Sönmez, Gonca; Türkal, Gamze; Telli, Nihat; Uçar, Gürkan
This study determined changes in the live lactic microflora of cow and goat milk kefirs, traditionally produced using kefir grain and freeze stored for 30 days, using high-throughput sequencing. In kefir grains, 71.29% Lactococcus, 16.27% Enterococcus, and 12.3% Serratia were found in the M17 agar, and 69.93% Lacticaseibacillus and 24.54% Lactobacillus were found in MRS agar. In the M17 agar of cow milk kefir, 78.26% Lactococcus was found on day 0, and this rate was 91.68%, 87.98%, and 88.14%, on the 7th, 14th, and 30th days, respectively. As for goat milk kefir, Lactococcus levels were 82.98%, 93.28%, 87.77%, and 84.92%, respectively. On the MRS agar in cow milk kefirs, Lacticaseibacillus levels were found as 56.98%, 61.21%, 87.54%, and 75.50%, on days 0, 7, 14, and 30 of storage, respectively, while the rates were 48.95%, 77.02%, 87.85%, and 83.38% for goat milk kefirs, respectively. As a result, although kefir beverages frozen at -25 degrees C contain sufficient levels of Lactobacillus and Lactococcus, it has been determined that the genus Serratia, which is one of the main spoilage factors in dairy products, is also increasing. Novelty impact statement In this study, the changes in the living lactic microflora during the frozen storage of traditional kefir beverages, whose production is increasing, were determined by high-throughput sequencing. It is thought that it is important to determine the effect of the freezing process on the viability of lactic acid bacteria, which are thought to have probiotic properties, for the long-term storage of these beverages. However, while lactic acid bacteria maintain their viability, it should be taken into account that microorganisms that are resistant to freeze conditions and cause spoilage can also develop.
Citation - WoS: 4
Citation - Scopus: 2
The Investigation of Structural and Magnetic Properties of Er2-Xcoxo3 Nano-Oxides
(Springer, 2022) Heiba, Zein K.; Arda, Lutfi; Doğan, Nurcan; Karatas, Ozgul; Mohamed, Mohamed Bakr
The sol-gel technique was used to synthesize Er2-xCoxO3 (0.0 <= x <= 0.30) mixed oxides to analyze structural and magnetic properties. The Rietveld analyses show that Er2-xCoxO3 nanoparticles up to x = 0.1 have single phase, for x >= 0.2 Co3O4 phase appears. Preferential cationic distribution between the non-equivalent sites 8b and 24d is found for all samples. A systematic variation is found in the average maximum strain with composition x. The magnetic analysis showed that super-paramagnetism is the reason of S-shaped hysteresis loops and also non-zero magnetic moments. Both Mr and Ms increased with increasing concentration of Co+2.
Citation - WoS: 20
Citation - Scopus: 23
Investigation of Usability of Boron Doped Sheep Wool as Insulation Material and Comparison With Existing Insulation Materials
(Elsevier Sci Ltd, 2022) Altın, Mustafa; Yıldırım, Giray Şamil
The limited energy resources in the world require maximum attention in energy saving and energy use. It has always been important to conserve energy by making thermal insulation in buildings which are one of the places where energy is used the most, and subsequently reducing environmental pollution as a result. The importance of existing thermal insulation materials in maintaining heat is already known. However, the damage they cause to the environment in their production is great, therefore insomuch that the manufacture and use of some insulation materials are prohibited. As a result, it is known that studies have been carried out to produce alternative thermal insulation materials. In this study, as a thermal insulation material, the usability of sheep wool which is an environmentally friendly, economical, and natural fiber, has been researched. A new insulation board was produced by adding boron to sheep wool, and this new insulation board was compared with rock wool and expanded polystyrene (EPS), which are widely used today. To carry out the experimental studies, an experiment building with full size and 3 rooms had been built. First, the building was completely covered with rock wool and the effect of the facades on the temperature and moisture in the environment was observed. Afterwards, as one room was covered with EPS and the other room was covered by the boron doped sheep wool insulation material, the insulation materials were compared wtih one another. In the experimental studies that was carried out, while rock wool gave the best results in ambient and surface temperature tests, EPS provided the best insulation in the moisture test. In the sound test, while rock wool and EPS absorbed the sound at very close decibel levels, the boron-doped sheep wool insulation material provided a higher level of sound insulation. In the experimental studies that was carried out, it has been determined that the boron-doped sheep wool insulation material has serious competition with both rock wool and EPS even with the first production of 10 mm.

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