Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Bulut, Hasan(53)
- Baskonus, Haci Mehmet(52)
- Alataş, Mevlüt(39)
- Gul, Muhammet(39)
- Serdar, Osman(38)
- Güler, Ömer(37)
- Akkurt, Nevzat(31)
- Benzer, Fulya(30)
- Sulaiman, Tukur Abdulkadir(29)
- Yucesan, Melih(29)
- Zengin, Gokhan(29)
- Kocabaş, Mehmet(28)
- Topal, Murat(26)
- Batan, Nevzat(25)
- Kök, Mediha(25)
- Ezer, Tülay(24)
- Paksoy, Mehmet Yavuz(24)
- Yildirim, Ozal(23)
- Tekin, H.O.(22)
- Utku, Anıl(22)
- ALMisned, Ghada(21)
- Ince, Muharrem(21)
- Öbek, Erdal(21)
- Erten, Fusun(20)
- Aslan, Naim(19)
- Celik, Erkan(19)
- Yildirim, Numan(19)
- Cakilcioglu, Ugur(18)
- Dal, Murat(18)
- Dal, Nursel Alp(18)
- Sahin, Kazim(18)
- Özkaynak, Fatih(18)
- Aslan, Alper(17)
- Erata, Hüseyin(17)
- Orhan, Cemal(17)
- Ergen, Burhan(16)
- Tanyol, Mehtap(16)
- Demir, Yakup(15)
- Etli, Serkan(15)
- Işık, Erdem(15)
Yayınlar
- MakaleAçık Erişim2023Theoretical and Practical Investigation of Stability Performance for Power Regulation in Hydroelectric Power Plants
Kahraman, Gökhan; Işık, Erdem
Hydroelectric power plants are the insurance of the interconnected system in order to provide fast energy to the system compared to other fossil fueled power plants. Hydroelectric power plants control the balance between the energy it supplies to the interconnected system and the pressurized water it uses with a system based on the fully automatic control principle. The quality of the energy supplied to the interconnected system depends entirely on this automatic control mechanism. In this study, mathematical models of the mechanisms that affect the automatic control system during the generation of energy in hydroelectric power plants are formed. Transfer functions of the obtained mathematical models are calculated by laplace transform. With the calculated transfer functions, the responses of the units of a hydroelectric power plant to the change of the amount of energy produced under different operating conditions are determined. The obtained data are compared with the actual conditions in a 1330 MW hydroelectric power plant with 8 Francis turbines. It is seen that the mathematical model and the turbine responses in real conditions are similar. In the calculations made at 115, 125, 135, 145 m. net head, the best stability conditions were obtained at 135 m. In addition, as a result of the calculations obtained under different operating conditions, ideal operating conditions are determined to minimize the fluctuations in energy production.
AtıfScopus2OpenAlex2
İncele - MakaleAçık Erişim2023Scopus SJRQ3Effect of 5.31Ti (at.%) content used as ternary in quaternary Cu-rich high-temperature shape memory alloy cast via arc melting
Başbağ, Güneş; Karaduman, Oktay; Canbay, Canan Aksu; Özkul, İskender; Boyrazlı, Mustafa
In this work, the new quaternary CuAlTiMg high-temperature shape memory alloy (HTSMA) with an unprecedented composition and with extended solubility of Ti was produced by the arc melting method. The thermal shape memory effect characterization tests were done by performing a series of differential calorimetric (DSC and DTA) measurements. The obtained thermograms of the alloy displayed the martensitic phase transformation peaks. The forward (martensite to austenite) phase transformation was found to occur at above 350◦C, which qualifies the produced alloy as an HTSMA. The microstructural XRD measurement was performed to reveal the atomic planes of martensite structures formed in the alloy, which constitute the shape memory effect property of the fabricated alloy. The alloy surface was monitored by optical microscopy image taken at room temperature, and finely dispersed Ti-rich X-phases were observed.
- MakaleAçık Erişim2023Scopus SJRQ3Effects of rosehip sauce on chemical, oxidative and sensorial quality of marinated anchovy (Engraulis Encrasicolus Linnaeus, 1758)
Kaya, Gülderen Kurt; Çoban, Özlem Emir; Bilici, Reşit
Marinated anchovies are of economic importance in Turkey. However, natural antioxidants affecting quality of marinated anchovies are rarely addressed. The purpose of this study is to compare olive oil and rosehip sauce as fillers in anchovy marinades. The study investigated the effects of rosehip sauce on the quality of marinated anchovies stored at 4°C. Anchovy were marinated with 4% acetic acid and 12% NaCl, put into plastic jars, filled with either olive oil or rosehip sauce and stored at 4°C. Changes in sensory attributes were determined during the process, and the following chemical parameters were monitored: total phenolic content (mg/100 g GAE), total volatile basic nitrogen (mg/100 g), pH, peroxide value (meq/kg) and thiobarbituric acid (mg MDA/kg). Values of total volatile basic nitrogen (TVB-N), peroxide value (PV) and thiobarbituric acid (TBA) increased during the storage. Higher values of TVB-N, TBA and PV were found in samples with olive oil than those with rosehip sauce. Samples with rosehip sauce demonstrated better oxidative stability. Rosehip sauce samples had higher appearance, odor, color and texture scores than olive oil samples.
AtıfScopus18WoS17OpenAlex15
İncele - MakaleAçık Erişim2023Scopus SJRQ2Automated Hypertension Detection Using ConvMixer and Spectrogram Techniques with Ballistocardiograph Signals
Ozcelik, Salih T. A.; Uyanık, Hakan; Deniz, Erkan; Sengur, Abdulkadir
Blood pressure is the pressure exerted by the blood in the veins against the walls of the veins. If this value is above normal levels, it is known as high blood pressure (HBP) or hypertension (HPT). This health problem which often referred to as the “silent killer” reduces the quality of life and causes severe damage to many body parts in various ways. Besides, its mortality rate is very high. Hence, rapid and effective diagnosis of this health problem is crucial. In this study, an automatic diagnosis of HPT has been proposed using ballistocardiography (BCG) signals. The BCG signals were transformed to the time-frequency domain using the spectrogram method. While creating the spectrogram images, parameters such as window type, window length, overlapping rate, and fast Fourier transform size were adjusted. Then, these images were classified using ConvMixer architecture, similar to vision transformers (ViT) and multi-layer perceptron (MLP)-mixer structures, which have attracted a lot of attention. Its performance was compared with classical architectures such as ResNet18 and ResNet50. The results obtained showed that the ConvMixer structure gave very successful results and a very short operation time. Our proposed model has obtained an accuracy of 98.14%, 98.79%, and 97.69% for the ResNet18, ResNet50, and ConvMixer architectures, respectively. In addition, it has been observed that the processing time of the ConvMixer architecture is relatively short compared to these two architectures.
AtıfScopus21WoS16OpenAlex21
İncele - Kitap BölümüAçık Erişim2023Production technique–structure relationship in bioceramic-coated scaffold applications
Aslan, Naim; Topuz, Mehmet; Aksakal, Bunyamin; Dikici, Burak
It is well known that the surface of metal-based implants is very resistive in aggressive body environments due to the noble oxide layer naturally formed on their surfaces. However, their osseointegration properties are very low. By the way, specific cells attached are desired on the implant surface when the surface of an implant connects with tissue in many circumstances. Thus in parallel with technological developments, biomedical engineering focuses on the growth of new tissue on the implant surface or in the porosities of the implant. The bulk properties of metallic scaffolds, especially Young’s modulus, can be controlled by the porosity ratio of the scaffold but cannot form a bond between the implant and tissue interfaces. Thus the coating of scaffold walls with a bioactive material is required. In this chapter, bioceramic coating techniques of scaffolds, mechanical and corrosion behavior, biocompatibility, and interactions of surface/tissue interface, especially considering the last published reports, were reviewed, in detail.
AtıfScopus4OpenAlex4İncele - MakaleAçık Erişim2023Scopus SJRQ2Surface Morphology, Structural, Photovoltaic and Optoelectronic Properties of Diamond Like Carbon-Copper Nanostructures
Kara, Salih; Aslan, Naim; Kurt, Mustafa Şükrü
In this work, we produced Cu doped diomond like carbon films using the magnetron sputtering technique and assessed their structural electrical and optoelectronic characteristics. In the atomic force microscopy (AFM) measurements, it was observed that the surface of the Cu-DLC nanocomposite films was in a granular form and the presence of cluster-like formations. D and G bands, which are the characteristic peaks of the DLC structure, were observed in the Raman spectrum, while Cu and C peaks were observed in the energy dispersive (EDX) spectrum. Photocurrent, photocapacitance, photosensitivity and photoresponse values increased depending on the increasing light intensity. However, the Cu-DLC/n-Si structure displayed low photovoltaic properties. The capacitance and conductance values were considerably affected by the increase in AC signal frequency. The series resistance and the density of the interface states exhibited low frequency dependent behavior which were obtained using the electrical characteristics of the nanocomposite films.
AtıfScopus7WoS7OpenAlex6İncele - MakaleAçık Erişim2023Scopus SJRQ3Performance evaluation of steel-concrete composite structures designed in poorly graded soils
Etli, Serkan
In this study, the seismic behavior of steel concrete composite buildings in a specific region was investigated. For this purpose, 5-, 10-, 15- and 20-storey composite moment-resisting framed structures were designed. Moment-resist-ing composite framed structures are modeled with concrete-filled steel tube columns and designed and modeled using composite beams. The buildings are designed according to ÇYTHYE-2016 and TBEC-2018 regulations at design levels with high ductility. In the design of the designed structures, the peak ground acceleration value is 0.79 g, and the design ground is planned as ZE class. SeismoStruct software was used for the design and performance evaluation of the structures. During the performance evaluations of the structures, nonlinear static pushover and incremental dynamic analyzes were used. Uniform and triangular load distributions are adopted in the static pushover analysis and 16 earthquake ground mo-tions are used in the incremental dynamic analysis. Evaluation of the effect of the number of stories on the earthquake behavior of composite moment-resisting framed structures was investigated using the non-linear analyzes mentioned. Ac-cordingly, lateral response, overstrength factors, ductility, and dynamic behavior factor values for composite frame struc-tures were calculated and presented using the relevant analysis results. It has been calculated that the behavior factor of all moment-resisting composite framed structures can perform well above the design assumptions, whereas moment-resistant composite framed structures absorb seismic energy by using inelastic deformations. Ductility is almost 30% higher than the design assumption for international standards. As a result, it was concluded that these structures could continue to serve theoretically.
AtıfScopus6WoS3OpenAlex9İncele - MakaleAçık Erişim2023Scopus SJRQ1An Integrated Approach for Assessing Suppliers Considering Economic Sustainability Innovation
Ahmadi, Hadi Badri; Pamucar, Dragan; Pourhejazy, Pourya; Kaya, Sema Kayapinar; Liou, James J. H.
Innovation plays a key role for improving the sustainability performance of corporations. A truly sustainable innovative firm needs to take the social, environmental, and economic aspects of sustainable innovation into consideration. However, limited studies have investigated the economic aspect of sustainable innovation, especially in the context of supplier evaluation from emerging economies. To deal with this issue, this manuscript puts forward a criteria decision framework for evaluating economic sustainable innovative suppliers. A new methodology based on fuzzy Full Consistency Method (FFUCOM) and Improved Combinative Distance-based Assessment (ICODAS) is developed and extended using interval rough Dombi-Bonferroni operators. In the developed approach, the FFUCOM is employed to determine the criteria weights, and the ICODAS is responsible for assessing and ranking the suppliers. A case study from the manufacturing sector of an emerging economy is considered for validating the developed framework and decision model. The findings introduce the 'financial resumption of products' as the most critical economic innovation criterion for evaluating suppliers. This article significantly helps decision-makers and practitioners to better comprehend the underpinnings of sustainable innovation economic dimension, particularly when assessing their suppliers. Furthermore, the applicability and validity of the proposed model was confirmed by the results of sensitivity analysis. Findings demonstrated that the proposed method is a solid and useful MCDM framework, and its outputs are precise and acceptable.
AtıfScopus9OpenAlex6İncele - MakaleAçık Erişim2023Scopus SJRQ2Paleoseismology of the Ganos segment; the western extend of the North Anatolian Fault (Turkey)
Aksoy, Murat Ersen; Meghraoui, Mustapha; Ferry, Matthieu; Çakir, Ziyadin; Uçarkuş, Gülsen; Sançar, Taylan; Altin, Mehmet Uğur
The Ganos fault that ruptured on 9 August 1912 (Mw: 7.4) is the westernmost inland segment of the North Anatolian fault (NAF). Here, the Ganos fault is bounded at its two tips with offshore faults segments, in the Sea of Marmara to the east and the Gulf of Saros to the west in the North Aegean Trough. Therefore, the paleoseismology of the 45-km-long inland fault is of importance to the seismic hazard analysis related to offshore active faults and in particular for the seismic gap in the Marmara Region. Earlier studies have established an earthquake chronology for the western and eastern inland tips of the Ganos fault. Here, we extend the paleoseismic studies toward the central segment. Three trenches at Yörgüç have revealed evidence for two faulting events, possibly post-1669 CE ±30 years, which can be correlated to the 1659 or 1766, and the 1912 historical earthquakes. At Yeniköy, we determined an offset of 46 ± 1 m and 47 ± 1 m on a stream channel and a ridge-crest, respectively. In two trenches we determined two faulting events for the last 1000 years and seven events for the last 3500 years. In trench T5, the base of the displaced stream channel provides a calibrated date of 829–591 BCE. Using the 46 ± 1 m right-lateral displacement, we calculate a slip rate of 16.9 ± 0.7 mm/year for the last 2732 ± 119 years. A combined analysis with earlier paleoseismic studies on the Ganos fault suggests that the historical earthquakes of 1912, 1766b or 1659, 1354 or 1343a, and 1063 ruptured the entire inland fault section. In such a case, the recurrence interval for this section of the NAF corresponds to 283 ± 81 years. Combining earlier estimations, we suggest an average slip rate of 17.1 ± 0.9 mm/year for the last 2700 years and observe a characteristic slip behavior of 4.5 to 5 m per event for this section of the North Anatolian plate boundary fault.
AtıfScopus1OpenAlex2İncele - MakaleAçık Erişim2023Scopus SJRQ1A comprehensive study on structural properties, photon and particle attenuation competence of CoNiFeCr-Ti/Al high entropy alloys (HEAs)
Sakar, Erdem; Guler, Omer; Alım, Bünyamin; Say, Yakup; Dikici, Burak
It is well known that high entropy alloys (HEAs) have a wide range of potential applications as radiation shielding due to their superior properties. The CoNiFeCr-Ti/Al compositions were chosen for their low cost as HEA in this study. The HEAs were successfully produced using the mechanical alloying (MA) method with equimolar CoNiFeCr, CoNiFeCrAl, and CoNiFeCrTi compositions. The production and structural properties of the alloys were investigated in detail. Besides, the photon and particle radiation shielding properties of the HEAs were calculated with the help of Phy-X/PSD, SRIM (10 keV-20 MeV), and ESTAR (10 keV-20 MeV) programs. The photon-matter interaction parameters were calculated in both specific photon energies emitted from 241Am, 133Ba, 109Cd, 60Co, 137Cs, 131I, and 22Na nuclides and a continuous energy range of 15 keV-15 MeV. The characterization of the alloys was investigated by using X-ray diffraction (XRD) and scanning electron microscopes (SEM) attached to an energy dispersive spectroscopy (EDX). It was found that the HEAs have a highly amorphous structure due to the selected production method. The crystal size of the alloys was calculated as 70, 35, and 20 nm for CoNiFeCr, CoNiFeCrAl, and CoNiFeCrTi, respectively. In terms of shielding properties, it has been determined that the produced HEAs have better shielding characteristics for photon and particle radiations than standard shielding concretes. In addition, the results demonstrated that CoNiFeCr alloy, which has the best shielding ability among the HEA alloys, can be used as a shielding material application requiring photon, electron, proton, alpha, and neutron radiations.
AtıfScopus30WoS32OpenAlex32İncele - MakaleAçık Erişim2023Scopus SJRQ2Modeling the electrical conductivity value of the model solution
Sabanci, Serdal; Kaya, Kübra; Göksu, Ali
The ohmic heating process is one of the novel electrical heating methods that are considered as fast, homogeneous and efficient heating. In this study, the details of the relationship between electrical conductivity (EC)-Temperature (Temp) and EC-pH-Temp at different Total Soluble Solid Content (TSSC) and different pH values were examined. Especially, the study explains details of the electrical conductivity value due to pH change (2, 2.5, 3, 3.5) and expressing EC change depending on the pH value of fruit and vegetable juices. At constant pH, EC values decrease with increasing TSSC values (10%, 20%, 30%, 40%, 50%, 60%) and decrease with increasing pH at constant TSSC value. When the relationship between Temp-EC is analyzed that the EC value increases as Temp increases in all cases and this increase is linear. It was found that the Temp-EC relationship was in high compatibility with an R2 value above 0.97. Also, in the Temp-EC-pH relationship, the R2 value was found to be an acceptable value above 0.95.
AtıfScopus4WoS3İncele - MakaleAçık Erişim2023Scopus SJRQ3Effect of glass sand used as aggregate on micro-concrete properties; [Učinak recikliranog stakla kao agregata na svojstva mikrobetona]
Etli, Serkan
Micro-concrete (MC) can be defined as a high-performance cement-based material produced using microaggregates and cement in the required proportions. Owing to its high performance, it has the potential to be used in the structural repairs of existing building elements. Within the scope of this study, an evaluation was conducted by creating a usage scenario under which glass, which is a waste product, can be reduced and applied in a way that provides a sufficient MC performance. There are four different binder contents in the mixtures within the scope of the present study, i.e., 570, 580, 599, and 658 kg/m3. From these mixtures, together with the control mixture, 12 %, 27 %, and 50 % microaggregates were replaced with glass sand and 16 different mixtures with a total of 4 different aggregate contents were produced. For the mechanical, physical, and durability tests, 40 × 40 × 160 mm sized prisms and 50 × 50 × 50 mm sized cubes were produced. For the purposes of this research, mechanical tests were carried out on 144 7-, 28- and 56-day old prismatic specimens. In addition, the effects of a freeze-thaw and temperature on the mechanical properties were investigated on 192 prismatic samples. In determination of the durability, physical properties such as the porosity, sorptivity, and specific gravity were tested and determined using cubic samples. The test results show that the replacement of MA with GS has positive effects on all mechanical behaviours of MC.
AtıfScopus7OpenAlex12İncele - MakaleAçık Erişim2023Scopus SJRQ3Seasonal changes in fatty acid profile of the freshwater snail Viviparus contectus (Millet, 1813) from lake habitat
Özçiçek, Esin; Kutluyer Kocabaş, Filiz; Kocabaş, Mehmet; Yilmaz, Ökkeş
The freshwater snail, Viviparus contectus, is an important shellfish owing to its nutritional composition (i.e., high amounts of protein, essential amino acids, fatty acid profile and minerals) and its promise as a candidate for the treatment of some diseases in traditional medicine. Hence, the seasonal changes in the fatty acid (FA) profile of Viviparus contectus caught from Demirköprü Dam Lake were determined in this study. Saturated fatty acid (SFAs) (64.54–80.39% of total fatty acids) had the highest concentration followed by polyunsaturated fatty acids (PUFAs) (10.63–21.83%) and monounsaturated fatty acids (MUFAs) (6.57–10.13%). Stearic acid (C18:0) was the major SFA while arachidonic acid (C20:4 n−6) was the major PUFA. The season significantly affected the FA profile of V. contectus while no significant difference was determined between seasons with respect to tissue MUFAs levels. A higher level of total SFAs was detected during spring (80.39%) while a higher proportion of MUFAs was detected during the winter (10.13%). The total amounts of PUFAs were highest in winter (21.83%). Overall, V. contectus has nutritional value. However, V. contectus caught in autumn may be nutritionally the most valuable for human consumption due to higher eicosapentaenoic acid 20:5 n−3 and docosahexaenoic acid contents.
AtıfScopus3WoS1OpenAlex4İncele - MakaleAçık Erişim2023Scopus SJRQ2Effects of İnclined Plate in a Channel to Control Melting of PCM in a Body İnserted on the Bottom Wall
Öztop, H.F.; Bakır, E.; Selimefendigil, F.; Gür, M.; Coşanay, H.
A two-dimensional time-dependent computational analysis was carried out to examine the effects of inclined plate on melting time of Phase Change Material (PCM) filled square block on the bottom wall of a channel. Solution of the governing equations are performed by using finite volume method. The RT25HC material is chosen as PCM. The study is done for different parameters of inclination angle of the plate and Reynolds number. It is observed that the inclined plate can be used to control of melting time of PCM in a block as well as flow field and temperature distribution in the channel. Using of acceleration angle as θ = 110° accelerates the melting time of PCM inside the block. Thus, mass fraction rate increases 4 times with application of inclined thin plate.
AtıfScopus31WoS27OpenAlex29İncele - MakaleAçık Erişim2023Scopus SJRQ4The Assessment of Health Risk from Heavy Metals with Water Indices for Irrigation and the Portability of Munzur Stream: A Case Study of the Ovaclk Area (Ramsar Site), Türkiye
Kutlu, Banu; Sarlgül, Ali
Surface water samples from the area of Munzur Stream in Türkiye (a Ramsar site) were evaluated for their suitability for irrigation and drinking purposes using different water quality indices. The human health risks were assessed as well. The study was conducted over a period of 24 months from January 2019 to December 2021 by taking samples from nine stations every month in order to determine the water quality of Munzur Stream, located in Tunceli. According to the results, Munzur Stream is in good condition in terms of the quality of drinking water and irrigation water. The concentrations of heavy metals such as Cu, Ni, Fe and Hg were high, though the water quality parameter according to Türkiye Ministry of Forestry and Water Affairs Surface Water Quality Regulations (TSWQR) was significantly lower than the permitted limits. In Munzur Stream, the irrigation water for all stations was reported to be excellent, good and suitable in terms of SAR, Na% and MH, respectively. The principal component analysis data formed the four principal components, explaining 98.22% of the total variance. The sources of pollution in this area include the rock types of the basin, soil erosion, domestic waste water discharge and agricultural flow of inorganic fertilisers.
AtıfWoS1OpenAlex3İncele - MakaleAçık Erişim2023Scopus SJRQ3Structural, physical, and radiation absorption properties of a significant nuclear power plant component: A comparison between REX-734 and 316L SS austenitic stainless steels
Say, Yakup; Güler, Ömer; Kavaz, Esra; ALMisned, Ghada; Ene, Antoaneta; Tekin, Huseyin Ozan
Austenitic stainless steels (SSs) are commonly used as in-core and surrounding structural materials in today’s industrial BWR and PWR systems. Such adaptable steels have also been the primary materials studied and used in several advanced nuclear reactor technologies, such as fast breeding and magnetic fusion reactors. In this study, some critical material properties, such as structural, physical, and radiation-shielding properties of REX-734 and 316L SS, were experimentally evaluated and compared to those of a number of other alloys. In addition to homogeneous element distribution, both alloys exhibit strong crystal orientation. The REX-734 alloy has a tensile strength of 1,259 MPa, whereas the 316L SS alloy has a tensile strength of 495 MPa. Moreover, nitrogen in the REX-734 alloy formed ultra-hard nitrides with Cr, Nb, and Si and precipitated into the structure and increased the strength. According to our findings, the mass attenuation coefficient values of the 316L SS sample were slightly higher than those of the REX-734 sample at all energies. It can be concluded that the REX-734 sample, with its exceptional strength qualities and excellent radiation attenuation capabilities, may be a viable nuclear power plant material for future investigations.
AtıfScopus7İncele - MakaleAçık Erişim2023Scopus SJRQ3Investigation of thermophysical properties of synthesized SA and nano-alumina reinforced polyester composites
Şahal, Hakan; Aydoğmuş, Ercan; Arslanoğlu, Hasan
Synthesis and characterization of 4-[(E)-(5-bromo-2-hydroxybenzylidene) amino]-N-(4-methylpyrimidin-2-yl) benzenesulfonamide (SA) has been performed. Alumina (Al2O3) and SA reinforced polyester composites are synthesized, and characterization processes are carried out. SA formed has been characterized by Fourier transform infrared (FTIR) spektrofotometre and nuclear magnetic resonance (NMR) spectroscopy. The thermal decomposition behavior of the nanocomposites in a nitrogen environment under non-isothermal conditions from 298 to 973 K is investigated with proportional-integral-derivative (PID) system. Thermal conductivity, Shore D hardness, and thermal decomposition behaviors of the nanocomposites that are added with alumina filler and synthesized with SA reinforcement have been compared. Nano-alumina filler raises the thermal conductivity coefficient and Shore D hardness of the polyester composites. The addition of synthesized SA reduces both the thermal conductivity coefficient and Shore D hardness. The thermal conductivity coefficient has been measured at the lowest in the pure polyester (0.056 W/m·K), and highest in the nano-alumina reinforced composite (0.072 W/m·K). The lowest Shore D hardness (nearly 68) is determined in the synthesized SA reinforced composite. Also, the experimental study has been optimized with the help of response surface methodology (RSM), and the improved theoretical models have been evaluated by statistical analysis.
AtıfScopus5WoS6OpenAlex13İncele - MakaleAçık Erişim2023Scopus SJRQ3The effect of different boron compounds on nutrient digestibility, intestinal nutrient transporters, and liver lipid metabolism
Şahin, Emre; Orhan, Cemal; Erten, Füsun; Şahin, Fikrettin; Şahin, Nurhan; Şahin, Kazim
Background/aim: Gastrointestinal health is essential for maintaining a healthy lifestyle. Improving nutrient absorption and energy metabolism are the critical targets for intestinal health. This study aimed to determine the effects of different boron (B) derivatives on nutrient digestibility, intestinal nutrient transporters, and lipid metabolism in rats. Materials and methods: Twenty-one rats were allocated to three groups (n = 7) as follows: (i) Control, (ii) Sodium pentaborate pentahy-drate (SPP), and (iii) boric acid (BA). The rats were fed a chow diet (AIN-93M) and supplemented with 8 mg/kg elemental B from SPP (45.2 mg/kg BW) and BA (42.7 mg/kg BW) via oral gavage every other day for 12 weeks. The nutrient digestibility of rats in each group was measured using the indigestible indicator (chromium oxide, Cr2 O3, 0.20%). At the end of the experiment, animals were decapitated by cervical dislocation and jejunum, and liver samples were taken from each animal. The nutrient transporters and lipid-regulated transcription factors were determined by RT-PCR. Results: The nutrient digestibility (except for ash) was increased by SPP and BA supplementation (p < 0.05). SPP and BA-supplemented rats had higher jejunal glucose transporter 1 (GLUT1), GLUT2, GLUT5, sodium-dependent glucose transporter 1 (SGLT1), fatty acid transport protein-1 (FATP1), and FATP4 mRNA expression levels compared to nonsupplemented rats (p < 0.0001). BA-supplemented rats had remarkably higher peroxisome proliferator-activated receptor gamma (PPARγ) levels than nonsupplemented rats (p < 0.0001). In contrast, sterol regulatory element-binding protein 1c (SREBP-1c), liver X receptor alpha (LxR-α), and fatty acid synthase (FAS) levels decreased by SPP supplementation compared to other groups (p < 0.05). Conclusion: SPP and BA administration enhanced nutrient digestibility, intestinal nutrient transporters, and liver lipid metabolism in rats.
AtıfScopus8WoS7OpenAlex9TR Dizin1İncele - MakaleAçık Erişim2023Scopus SJRQ2Expression of phoenixin-14 and nesfatin-1 in the hypothalamo–pituitary–gonadal axis in the phases of the estrous cycle
Parlak Ak, Tuba; Yaman, Mine; Bayrakdar, Ali; Bulmus, Ozgur
Phoenixin-14 (PNX-14) and nucleobindin 2 (NUCB2)/nesfatin-1 are regulatory neuropeptides expressed in the hypothalamus. These neuropeptides can be effective in hormonal regulation of the hypothalamo–pituitary–gonadal (HPG) axis and reproductive functions. In the present study, the distribution of PNX-14 and NUCB2/nesfatin-1 in the hypothalamus, pituitary, ovary, and uterus tissues during the phases of the estrous cycle in female rats was investigated. Eighteen Wistar Albino rats determined among animals showing regular estrous cycle by vaginal smear method were divided into three groups: proestrus (Group I), estrus (Group II) and diestrus (Group III). Serum gonadotropin-releasing hormone (GnRH), plasma PNX-14, and NUCB2/nesfatin-1 concentrations were the highest, moderate, and lowest in estrus, diestrus, and proestrus phases, respectively. PNX-14 immunoreactivity in the supraoptic and arcuate nuclei of the hypothalamus and NUCB2/nesfatin-1 immunoreactivity in the paraventricular nuclei were particularly evident in the estrus phase. These neuropeptide immunoreactivities were decreased in different cells of anterior pituitary during proestrus compared with those during estrus and diestrus. PNX-14 immunoreactivity in the ovary, especially during the estrus phase, was diffuse and intense in the granulosa and luteal cells and oocytes, and it was few and weak in theca cells. In addition, NUCB2/nesfatin-1 immunoreactivity was abundant and strong in granulosa and luteal cells, theca and interstitial cells, and oocytes during estrus. In the estrus phase, PNX-14 immunoreactivity was strong in the glandular epithelial cells and stromal cells of the endometrium, also NUCB2/nesfatin-1 immunoreactivity was strong in the epithelial and glandular epithelial cells. As a result, when the estrous cycle was evaluated, it was concluded that the changes in the distribution of PNX-14 and NUCB2/nesfatin-1 at all phases were related to GnRH and that these neuropeptides showed the highest immunoreactivity especially in the HPG axis and uterus tissues of estrus rats.
AtıfScopus21OpenAlex22İncele - MakaleAçık Erişim2023Scopus SJRQ3Bioremediation of herbicide diquat dibromide from aqueous solution with white rot fungus Phanerochaete chrysosporium
Yildirim, Numan; Ciftci, Emine; Erguven, Gokhan Onder; Durmus, Barbaros
In this study, the fungal bioremediation of herbicide diquat dibromide (DD) by white rot fungus Phanerochaete chrysosporium was studied. After bioremediation, the reduction in toxicity of the remediated media was evaluated by Daphnia magna as a model organism. For bioremediation studies, flask-level batch experiments were performed at different DD concentrations (10, 20 and 50 ppm) under static and agitated conditions. The highest reduction rates of chemical oxygen demand and total organic carbon were determined as 85.92 (for 20 ppm DD) and 87.46% (for 10 ppm DD), respectively under agitated conditions. After bioremediation, D. magna bioassay was used for toxicity assessment during 24, 48 and 72-h periods. In current study, it was observed that P. chrysosporium has very effective bioremediation capacity for diquat dibromide. The D. magna bioassay revealed that P. chrysosporium provides effective reduction in toxicity of diquat dibromide.