Yayınlar
Koleksiyondaki öğeler
- MakaleAçık Erişim2018Scopus SJRQ1Determination of effective constitutive parameters of inhomogeneous metamaterials with bianisotropy
Hasar, Ugur Cem; Buldu, Gul; Kaya, Yunus; Ozturk, Gokhan
A recursive algorithm is proposed to accurately extract the electromagnetic parameters of isotropic/bianisotropic metamaterial (MM) slabs of inhomogeneous structures. The algorithm is based on the recursive calculations of measured/ simulated forward and backward scattering (S-) parameters from previously extracted wave impedances and refractive indices of each homogeneous layer (except the analyzed intermediate layer) by a suitable retrieval method. There are two main advantages of our proposed method over existing extraction algorithms. First, it could retrieve the electromagnetic parameters of both isotropic and bianisotropic MM slabs. Second, it is applicable for electromagnetic parameter extraction of inhomogeneous structures. For validation of our method and assessing its accuracy over existing extraction methods, we used the simulation results of various inhomogeneous structures constructed by different isotropic/bianisotropic MM slabs (split-ring-resonator (SRR), SRR-wire, omega, and omega-wire). For completeness, the effects of noise present in S-parameters and iterative error (by increasing the value of iteration numbers) are examined to test the robustness of the proposed algorithm.
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İncele - MakaleYalnız künye2018Scopus SJRQ3Synthesis and Characterization of Hydroxyapatite/TiO2 Coatings on the β-Type Titanium Alloys with Different Sintering Parameters using Sol-Gel Method
Dikici, B.; Niinomi, M.; Topuz, M.; Say, Y.; Aksakal, B.; Yilmazer, H.; Nakai, M.
In this study, hydroxyapatite (HA) based composite films were successfully syntheses on the β-type Ti29Nb13Ta4.6Zr (TNTZ). The solutionized TNTZ substrates coated with HA and HA/Titania (TiO2) bioactive composite coatings by sol-gel method under various sintering parameters related to sintering temperatures and heating ramp rates. Microstructural observations of the coatings revealed that apatite was formed on the substrates. The hardness values of the coatings increase with increasing both the sintering temperature and the TiO2 concentration in the coatings layer. However, it was found that the heating ramp rate of the sintering was not affecting the hardness values so much. Also, the hardness values of the HA/TiO2 composite coatings at all sintering temperatures were higher than only HA coated TNTZ samples due to the existence TiO2 phases in the HA matrix. Results indicating that the doping of HA with TiO2, improve the physical consistency between the coating layer and the substrates and provide a better inter-particle bonding due to the existence TiO2 phases in the HA.
AtıfScopus42OpenAlex43İncele - MakaleAçık Erişim2019Scopus SJRQ4α-D-glucopyranosyl-(1→2)-[6-O-(L-tryptophanyl)-β-D-fructofuranoside]
Kyeremeh, Kwaku; Kwain, Samuel; Tetevi, Gilbert Mawuli; Camas, Anil Sazak; Camas, Mustafa; Dofuor, Aboagye Kwarteng; Deng, Hai; Jaspars, Marcel
The Mycobacterium sp. BRS2A-AR2 is an endophyte of the mangrove plant Rhizophora racemosa G. Mey., which grows along the banks of the River Butre, in theWestern Region of Ghana. Chemical profiling using 1H-NMR and HRESI-LC-MS of fermentation extracts produced by the strain led to the isolation of the new compound, α-D-Glucopyranosyl-(1→2)-[6-O-(L-tryptophanyl)-β- D-fructofuranoside] or simply tortomycoglycoside (1). Compound 1 is an aminoglycoside consisting of a tryptophan moiety esterified to a disaccharide made up of β-D-fructofuranose and α-D-glucopyranose sugars. The full structure of 1 was determined using UV, IR, 1D, 2D-NMR and HRESI-LC-MS data. When tested against Trypanosoma brucei subsp. brucei, the parasite responsible for Human African Trypanosomiasis in sub-Saharan Africa, 1 (IC50 11.25 µM) was just as effective as Coptis japonica (Thunb.) Makino. (IC50 8.20 µM). The extract of Coptis japonica (Thunb.) Makino. is routinely used as laboratory standard due to its powerful antitrypanosomal activity. It is possible that, compound 1 interferes with the normal uptake and metabolism of tryptophan in the T. brucei subsp. brucei parasite.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2018Scopus SJRQ1An optimisation support for the design of hybrid production lines including assembly and disassembly tasks
Mete, Süleyman; Çil, Zeynel Abidin; Özceylan, Eren; Ağpak, Kürşad; Battaïa, Olga
The optimisation problems related to the assignment of tasks to workstations in assembly and disassembly lines have been largely discussed in the literature. They are known, respectively, as Assembly Line Balancing and Disassembly Line Balancing Problems. In this study, both types of task performed on the identical product are integrated in a common hybrid production system. Therefore, the logistic process is simplified and disassembly tasks can supply easier the assembly tasks with the required components. The considered production system has the layout of two parallel lines with common workstations. The product flow is conventional in the assembly line and reverse in the disassembly line. The paper provides a new mathematical model for designing such a hybrid system and an approximate approach based on ant colony optimisation for solving large-scale instances. The solution method is tested in a case study. The obtained results are compared with the solution provided by the design of two independent lines. The analysis of the results highlights the potential benefits of the hybrid production system.
AtıfScopus53OpenAlex51İncele - MakaleAçık Erişim2020Scopus SJRQ1Remediation of pollutants with economical importance from mining waters: Usage of Cladophora fracta
Topal, Murat; Arslan Topal, E. Is̨ıl; Öbek, Erdal
The accumulations of elements (Mo, Cu, Zn and Ni) those have both pollutant characteristics and economic importance were determined in the macroalga (green alga Cladophora fracta) exposed to mining water with the aim of presentation of the possibility of using the alga as a bioindicator of these elements. The highest element concentrations (Mo, Cu, Zn and Ni) accumulated by Cladophora fracta were determined as 2.38; 19.66; 4510.5 and 19.4 mg/kg, respectively. Bioconcentration factor values decreased in the order: Ni>Cu>Mo>Zn. The Metal Pollution Index (MPI) values calculated between 17.50 and 44.98 were used to determine the pollution degree of Cladophora fracta. As a result, it was determined that Cladophora fracta highly accumulated the elements from the mine gallery water. Therefore, Cladophora fracta was a good bioaccumulator and indicator for the remediation of the elements in mine gallery waters.
AtıfScopus8WoS4OpenAlex8İncele - MakaleYalnız künye2020Scopus SJRQ1Structural, elastic, optical and γ-ray shielding behavior of Dy3+ ions doped heavy metal incorporated borate glasses
Divina, R.; Sathiyapriya, G.; Marimuthu, K.; Askin, A.; Sayyed, M.I.
The effect of modifier ions in different basis have been analyzed through a new series of heavy metals incorporated borate based glasses 39H3BO3+30PbO+20MO+10Bi2O3 +1Dy2O3 (where M=Ca,Sr,Ba,Na and K) which are synthesized following melt quenching technique for radiation screening applications. The potentiality of glasses to withstand the penetration of fast moving neutrons is checked by various studies. Functional groups are identified through different stretching and bending modes of vibrations within the glass membrane through FTIR spectral analysis. In addition to that, other structural properties like Boron-Boron distance (dB−B), molar volume of oxygen (Vo), Oxygen Packing Density (OPD), optical basicity (Λth) and Bond density (nb) are calculated theoretically. The bonding nature (β) and nephelauxetic ratio (δ) values reveals that the glasses possess more of ionic linkages. The high density value exhibited by the Bismuth lead borate glasses indicates their capability to act as a good shielding material in reactors emitting hazardous radiation. Different moduli of elasticity (E, K, G, σ) values for the present glasses are calculated and the results reveal the enhancement in shielding performances when compared to other existing glasses and a comparative study is made on it. Optical studies are carried out and the absorption of Dy3+ions to different energy levels is observed and optical band gap (Eopt) values of the synthesized glasses are calculated along with the Urbach energy (ΔE) values. Radiation shielding properties of the produced glasses were investigated in terms of the mass attenuation coefficients (µm), transmission fraction (T), half value layer (HVL) and effective atomic number (Zeff) parameters. The results attained in the shielding study indicated that glass specimen with M = Ba exhibits enhanced shielding behavior as Ba owns high atomic number (Z) compared to other elements. Glass specimen with M = Na shows the poorest shielding characteristics due to the low Z of Na.
AtıfScopus117OpenAlex107İncele - MakaleYalnız künye2019Scopus SJRQ2Synthesis, physical, structural and shielding properties of newly developed B2O3–ZnO–PbO–Fe2O3 glasses using Geant4 code and WinXCOM program
Rammah, Y.S.; Askin, A.; Abouhaswa, A.S.; El-Agawany, F.I.; Sayyed, M.I.
New zinc lead borate glasses with (50B2O3–10ZnO–(40 − y) PbO)–yFe2O3: 0 ≤ y ≤ 10 wt%) composition were synthesized by the conventional melt-quench technique. The amorphous nature of the glasses was tested by using X-ray diffraction spectroscopy. FTIR spectra for the glasses were recorded in the range of 4000–400 cm−1. Physical properties of the proposed glasses were evaluated. The mass attenuation coefficients (μ/ρ) for the glasses were calculated by the Geant4 simulation toolkit code and XCOM software within the photon energy range 365–2510 keV. Different γ-ray shielding parameters such as half-value layer, tenth value layer, and transmission fraction for the proposed glasses were evaluated using the obtained values of the (μ/ρ). Results reveal that for 1 cm glass thickness, the (50B2O3–10ZnO–30PbO)–10Fe2O3 sample has the highest transmission, due to the lower amount of Pb, and thus poorer shielding capability among the other glass samples. In addition, the probabilities of γ-ray interaction with the studied glasses were investigated.
AtıfScopus62OpenAlex64İncele - MakaleAçık Erişim2018The antiiflammatory effect of Ginkgo biloba in lipopolysaccharide-induced rat sepsis model
Ilhan, Nevin; Susam, Solmaz; Ak, Tuba Parlak; Baykalir, Burcu Gul
Background: Sepsis is characterized dysregulated inflammatory response and is the leading cause of organ failure or injury and death in critical care units. Ginkgo biloba extract 761 (EGb 761) is characterized by antioxidant activity. There is no clear data in the functional role of EGb 761 that inhibiting of proinflammatory cytokines exist in sepsis. The purpose of this study was to investigate the antiinflammatory effect of EGb 761 on the levels of vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9) and inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS) induced rat sepsis model. Methods: The animals were randomly divided into the following six groups: the control, LPS, flunixin meglumine (FM), EGb 761, LPS + FM and LPS + EGb 761 groups. Enzyme-linked immunosorbent assay (ELISA) analysis was applied to measure serum levels of VEGF, MMP-9, and iNOS. Results: Serum iNOs (p < 0.05), VEGF (p < 0.01) and MMP-9 (p < 0.05) levels were significantly higher in the sepsis group. Treatment with EGb 761 decreased serum iNOs levels (p < 0.01), VEGF and MMP-9 levels decreased significantly (p < 0.05). Also, treatment with FM decreased iNOs (p < 0.01), VEGF and MMP-9 levels significantly (p < 0.05). Conclusions: It is suggested that sepsis may lead to increase serum iNOs, MMP-9, and VEGF levels and treatment of EGb 761 may have a potential antiinflammatory effect against LPS-induced sepsis.
AtıfOpenAlex1İncele - Derleme MakaleYalnız künye2019Scopus SJRQ1Designing the airport service with fuzzy QFD based on SERVQUAL integrated with a fuzzy multi-objective decision model
Kayapınar, Sema; Erginel, Nihal
Airport service quality is a crucial issue in the transportation industry. Although many studies focus on service quality and measurement of the airports, only a small number of studies that consider linguistic expression and fuzzy approach exist in the literature. This study aims to propose a new integrated approach to develop airport service quality. An integrated approach involving fuzzy Quality Function Deployment (QFD) based on SERVQUAL is used to measure airport service quality and to determine fuzzy weights of technical design requirements. Firstly, passengers’ needs are prioritised by using the SERVQUAL method and gap scores, then QFD matrix is constructed by defining fuzzy relationships between passengers’ needs and expectations, and technical design requirements under imprecise knowledge. Technical design requirements are weighted by using fuzzy QFD matrix as fuzzy numbers. Finally, a fuzzy multiple objective decision model is proposed to select the significant technical design requirements with two objectives: maximising the total fuzzy weights of technical design requirements and minimising the fuzzy technical difficulty level under a fuzzy budget constraint. A two-phase approach is used to solve the constructed fuzzy multi-objective decision model. The final results indicate four design requirements named as ‘the number of information board’, ‘capacity of wi-fi’, ‘emergency help button and automation’, and ‘the number of the signboard’, which maximise the total fuzzy weights of technical design requirements and minimise the sum of the fuzzy technical difficulty of each design requirements under the fuzzy budget constraint. This study is a real-world application which was implemented at the Anadolu University Airport in Turkey.
AtıfScopus40WoS37OpenAlex47İncele - MakaleYalnız künye2019Scopus SJRQ3Effect of L-Tryptophan on Sperm Quality of Tigris Scraper (Capoeta umbla) (Pisces: Cyprinidae) after Cryopreservation
Kutluyer, F.; Aksu, Ö.; Kocabaş, M.
BACKGROUND: The aromatic amino acid L-tryptophan is a versatile molecule and needed for the biosynthesis of proteins. Due to metabolic functions, it has been widely used in research and clinical trials. OBJECTIVE: The present study aimed to test the usefulness of L-tryptophan as an extender of Tigris scraper (Capoeta umbla) sperm during cryopreservation. MATERIALS AND METHODS: Semen samples were diluted with a ratio of 1:3 (sperm: extender) and base extenders were supplemented with L-tryptophan (0 mM, 0.5 mM, 1 mM, 2 mM and 4 mM). Sperm motility and duration of post-thawed samples were assessed after the cryopreservation process. RESULTS: Our results revealed that motility rate and duration of sperm increased when the cryomedia was supplemented with L-tryptophan. On the other hand, an increase in the concentration of L-tryptophan in the extender caused a significant decrease (p<0.05) in the motility rate of Tigris scraper (C. umbla) sperm. The ideal results were obtained at 1 mM L-tryptophan; however, no motile sperm were shown in any samples when a concentration of 2 mM was used. CONCLUSION: The current study shows the importance of conducting further studies related to long-term storage and reproduction management.
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İncele - MakaleAçık Erişim2019Scopus SJRQ3Karyological investigation on five taxa of Bellevalia lapeyr. (Asparagaceae) from Turkey
Dogan, Gulden; Kiran, Yasar; Yavuz Paksoy, M.
The somatic chromosome numbers and karyotypes were examined in five Bellevalia taxa including two endemic species of B. chrisii and B. gracilis distributed in Turkey. The chromosome numbers were determined as 2n=2x=8 in all studied taxa [B. chrisii Yıldırım & B. Şahin sp. nov., B. glauca (Lindl.) Kunth., B. gracilis Feinbrun, B. longipes Post, B. sarmatica (Pallas ex Georgi) Woronow]. The karyotype formula was determined as 2m+sm+st in B. chrisii and B. longipes, 3m+st in B. glauca, B. gracilis and B. sarmatica. The findings for each of the analyzed taxa are compared with the results of previous studies.
- MakaleYalnız künye2019Scopus SJRQ3Utilizing hydrolyzed powder recyclates as filler in polystyrene; [Verwendung von hydrolisierten Pulverlackrecyclaten als Füllstoff in Polystyrol]
Kismet, Y.; Wagner, M.H.
In the present study, hydrolyzed powder coating wastes were used as filler materials in polystyrene compounds, and the effect on the mechanical properties, melt flow index and density of polystyrene compounds were investigated. Epoxy/polyester, epoxy and polyurethane systems with thermoset structure were used as powder coating recyclates. After separately hydrolyzing these wastes, 5 %, 10 %, 20 % and 30 % by weight were homogeneously mixed with polystyrene, initially mechanically and subsequently with an extruder in the melt at 180 °C. The resulting compounds were cooled and granulated, and by use of an injection molding machine at 180 °C to 200 °C, standard tensile test bars were produced. Tensile strength, bending strength and izod impact strength of the test bars were measured and the variations of the mechanical properties of the polystyrene compounds as a function of the type and amount of filler were examined. In addition, melt flow index and density of the compounds were determined. Furthermore, the bonding mechanism of filler and matrix material was examined by electron microscopy.
AtıfScopus2WoS2OpenAlex3İncele - MakaleYalnız künye2019Scopus SJRQ1Risk evaluation and prevention in hydropower plant operations: A model based on Pythagorean fuzzy AHP
Yucesan, Melih; Kahraman, Gökhan
Hydropower generation facilities are becoming increasingly popular in many parts of the world. One of the main reasons for this situation is that the resource reserves such as coal, petroleum and natural gas, which are called conventional energy sources, decrease day by day and their prices rise. So the efficient operation of hydroelectric power plants has become very important. When these plants are operated, it is possible to cause many hazards, including injury, illness, death, damage to the environment, property and equipment. In this study, it is aimed to perform risk assessment for hydroelectric power plants using Pythagorean fuzzy Analytical hierarchy process (PFAHP) method. The team of experts has identified twenty hazards and their results that could occur in the operation of the hydroelectric power plant. The weights of the hazards were determined by using linguistic expressions. Preventive measures have been taken for the three most important hazards. The results of this study are expected to contribute to the safety of hydropower plants and the prevention of financial losses.
AtıfScopus143WoS123OpenAlex147İncele - MakaleYalnız künye2020Scopus SJRQ2An Evaluation Research About Effects of Characterized Cadmium Selenide (CdSe) and Lead Selenide (PbSe) Quantum Dots on Brine Shrimp (Artemia salina)
Ates, Mehmet; Tastan, Burcu Ertit; Danabas, Durali; Cicek-Cimen, Isil Canan; Aksu, Onder; Kutlu, Banu; Unal, Ilkay; Arslan, Zikri
Quantum dots (QDs), such as cadmium selenide (CdSe) and lead selenide (PbSe) exhibit excellent optical, magnetic and chemical properties due to their extremely size (ca. 1–10 nm) and are attractive semiconductor nanomaterials for optical studies and energy storage. In this study, aqueous synthesis of CdSe and PbSe QDs in a size range of 2–10 nm was described. Synthesized QDs were characterized using SEM and TEM, DLS, zeta potential, FTIR, EDX and XRD. Highest accumulation (72.5 ± 5.8 mg L−1) of PbSe QDs occurred at 10 ppm suspensions. In general accumulation increased up to 48 h exposure then fluctuate tended to decline. For CdSe QDs, accumulation tended to decrease for 72 h exposure except that for 5 ppm groups. For the elimination period, in general, the elimination levels of PbSe and CdSe QDs from exposed individuals decreased (p < 0.05) even it has some fluctuate.
AtıfScopus6WoS4OpenAlex5İncele - MakaleYalnız künye2020Scopus SJRQ4Spermatologic characteristics and sperm motility alterations caused by short-term copper exposure in Brook Trout Salvelinus fontinalis
Kutluyer, Filiz; Kocabaş, Mehmet; Başçınar, Nadir
Spermatozoa movement in many aquatic animals with external fertilization is directly related to the external aqueous environment. In particular, environmental toxic metals can cause harmful effects and impair sperm cell functions. The high concentrations of copper (Cu) may be harmful for aquatic animals, while low levels are required for metabolic interactions. Herein, we investigated the effect of different copper concentration [0 mg L−1 (Control),.5 mg L−1, 1 mg L–1, and 2 mg L−1] on spermatozoa of brook trout Salvelinus fontinalis. Motility and survival of sperm cells were assessed. Our results indicated that Cu exposure caused to an evident decrease in motility and longevity of spermatozoa with increasing concentrations (p <.05). Overall, we showed that Cu exposure can impair sperm motility of S. fontinalis. Our study suggested that sperm motility has the potential to be a sensitive bioindicator of freshwater environmental pollution.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2019Scopus SJRQ2Ultrasound as pretreatment for drying garlic slices in microwave and convective dryer
Bozkir, Hamza; Rayman Ergün, Ahsen; Tekgül, Yeliz; Baysal, Taner
The effects of ultrasound pretreatment (US) before hot air drying (HAD) and microwave drying (MWD) of garlic slices were investigated. For this aim ultrasonic bath at 30 °C for 30 min (35 kHz), microwave oven at 540 W power and tray dryer at 60 °C and with 1.0 m/s air flow rate were used to reach the final moisture content of 5%. Drying rate increased in the US + HAD and the US + MWD groups by 19.30% and 13.82% respectively in comparison with control groups. The effective moisture diffusivity (D eff ) of garlic slices were calculated from Fick’s diffusion model for the HAD, US + HAD, MWD and the US + MWD groups as 1.420 × 10 −10 , 1.826 × 10 −10 , 1.177 × 10 −8 , 1.363 × 10 −8 m 2 /s respectively. The rehydration rates increased, and bulk densities were decreased in the US + HAD and the US + MWD compared to the control groups. The color values were significantly affected after ultrasound pretreatment. Redness, and yellowness increased most in the US + HAD group.
AtıfScopus53WoS47OpenAlex58İncele - MakaleAçık Erişim2019Scopus SJRQ4Digyaindoleacid A: 2-(1-(4-hydroxyphenyl)-3-oxobut-1-en-2-yloxy)-3-(1H-indol-3-yl)propanoic acid, a novel indole alkaloid
Kwain, Samuel; Tetevi, Gilbert Mawuli; Mensah, Thomas; Camas, Anil Sazak; Camas, Mustafa; Dofuor, Aboagye Kwarteng; Azerigyik, Faustus Akankperiwen; Deng, Hai; Jaspars, Marcel; Kyeremeh, Kwaku
Digyaindoleacid A (1) is one of the novel alkaloids produced by the Ghanaian Paenibacillus sp. DE2SH (GenBank Accession Number: MH091697) isolated from the mangrove rhizosphere soils of the Pterocarpus santalinoides tree growing in the wetlands of the Digya National Park, Brong Ahafo Region, Ghana. This compound was isolated on HPLC at tR ≈ 60 min and its structure determined by MS, 1D, and 2D-NMR data. When tested against Trypanosoma brucei subsp. brucei strain 927/4 GUTat10.1, 1 produced a half-maximal inhibitory concentration (IC50) 5.21 µM compared to the standard diminazene aceturate (IC50 = 1.86 µM). In the presence of normal mouse macrophages RAW 264.7, 1 displayed a higher selectivity towards T. brucei subsp. brucei (selectivity indices (SI) = 30.2) with low toxicity. This result is interesting given that the drug diminazene aceturate is considerably toxic and 1 is a natural product isolate. The structure of 1 incorporates the backbone of the amino acid tryptophan which is crucial in the metabolism of Trypanosoma brucei subsp. brucei strain 927/4 GUTat10.1. It is possible that 1, could interfere with the normal uptake and metabolism of tryptophan in the parasite. However, 1 (IC50 = 135.41 µM) produced weak antileishmanial activity when tested against Leishmania donovani (Laveran and Mesnil) Ross (D10).
AtıfScopus4WoS3OpenAlex4İncele - MakaleYalnız künye2020Scopus SJRQ2A novel proximity graph: Circular neighborhood cell graph for histopathological tissue image analyzing
Serin, Faruk; Erturkler, Metin
The cell is the smallest unit of living beings, which has structural and functional properties. Almost all cell behaviors are regulated by various intracellular reactions initiated by the signaling. The signaling and the distance between cells influence each other. Thus, cell-location-based modeling and analyzing of histopathological tissues provide important information to the expert. In literature, methods such as distance-based threshold, K-Nearest Neighbor, Voronoi graphs, Delaunay triangulation, and colored graph have been used. However, circular neighborhood relationships of cells have not been considered by any CAD system so far despite of its crucial impact. Thus, we developed the circular neighborhood cell-graph. Histopathological images of liver were classified by using features extracted from T-Distance, K-Nearest Neighbor, Voronoi, Delaunay, and the proposed cell-graph. Then, the classification performances of the methods were compared. Experimental results show that liver tissue images can be classified with accuracy of 95.7% by using the features provided by the proposed cell-graph model.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2020Scopus SJRQ4Occurrence of the freshwater jellyfish Craspedacusta sowerbii Lankester, 1800 from Uzunçayır dam lake (Tunceli), Turkey
Kutlu, Banu
In this study, Craspedacusta sowerbii Lankester, 1880 a jellyfish species belonging to freshwater hydrozoan group, was reported for the first time in the field study carried out at Uzunçayır dam lake in Tunceli province on 15 September 2018. The plankton samples were obtained from two different regions of the lake using UNESCO WP2 plankton net with mesh size of 200 µm. C. sowerbii, one of the fresh water hydrozoans obtained from plankton samples, is rarely observed in man-made lakes, ponds, and reservoirs, and has not been observed earlier in the Uzunçayır dam lake. The C. sowerbii might have placed in the lake through some fishing activities which were conducted from 2010 to 2017 and/or through some sport equipment's (i.e. boat, jetski, were brought to the region for recreational purposes).
AtıfScopus2İncele - MakaleYalnız künye2020Scopus SJRQ4Biochemical responses of some (Helianthus annuus L.) cultivars to the interaction effects of biodegradable polymer and salt stress
Akbulut, Gulcin Beker; Torgut, Gulben
Salt stress is one of the most important environmental factor limiting plant growth and causing serious agricultural problems in the world. Biodegradable poly(ethylene oxide)-co-(ε-caprolactone) poly(EO-co-ε-CL) copolymer synthesized by ring-opening polymerization (ROP) have been used to reduce this negative effect. For the characterization of this copolymer, the Fourier Transform Infrared (FT-IR), Proton Nuclear Magnetic Resonance (1H-NMR), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) techniques were used. To investigate the impact of copolymer and salt (200 mM NaCl) singly and in combination, on two different sunflowers (Helianthus annuus L. cv. 'Düet' and Helianthus annuus L. cv. 'Meteor') a series of experiments were established. In the seedlings grown for 21 days, differences in some metabolic parameters such as chlorophyll-a (Chl-a), chlorophyll-b (Chl-b), carotenoids (Car), total chlorophyll (Chl), total carbohydrate content, and malondialdehyde (MDA) content were examined. According to the result of our study, after the application of NaCl and poly(EO-co-ε-CL), significant changes were observed in the studied biochemical parameters. It was observed that the copolymer in both species had a healing effect against salt stress. Application of 200 mM NaCl caused an increase in MDA of both genotype, particularly in 'Meteor'. Higher Chl-a, Chl-b, total Chl, and Car contents were observed in 'Meteor' as compared to that in 'Düet' under saline conditions. Total carbohydrate content decreased with increasing salt stress in both cultivars.
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