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Analysis and Mitigation of Power Quality Issues in Distributed Generation Systems Using Custom Power Devices
(IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2018) Hossain, Eklas; Tur, Mehmet Rida; Padmanaban, Sanjeevikumar; Ay, Selim; Khan, Imtiaj
This paper discusses the power quality issues for distributed generation systems based on renewable energy sources, such as solar and wind energy. A thorough discussion about the power quality issues is conducted here. This paper starts with the power quality issues, followed by discussions of basic standards. A comprehensive study of power quality in power systems, including the systems with dc and renewable sources is done in this paper. Power quality monitoring techniques and possible solutions of the power quality issues for the power systems are elaborately studied. Then, we analyze the methods of mitigation of these problems using custom power devices, such as D-STATCOM, UPQC, UPS, TVSS, DVR, etc., for micro grid systems. For renewable energy systems, STATCOM can be a potential choice due to its several advantages, whereas spinning reserve can enhance the power quality in traditional systems. At Last, we study the power quality in dc systems. Simpler arrangement and higher reliability are two main advantages of the dc systems though it faces other power quality issues, such as instability and poor detection of faults.
Boletus edulis loaded with gamma-Fe2O3 nanoparticles as a magnetic sorbent for preconcentration of Co(II) and Sn(II) prior to their determination by ICP-OES
(SPRINGER WIEN, 2018) Kılınç, Ersin; Yalçın, M. Serkan; Kılınç, Ersin; Soylak, Mustafa
The authors show that the fungus Boletus edulis loaded with gamma-Fe2O3 nanoparticles is a viable sorbent for magnetic solid phase extraction of trace levels of Co(II) and Sn(II). The surface structure of immobilized magnetized B. edulis was characterized by FT-IR, SEM and EDX. Experimental parameters were optimized. Following elution with 1 M HCl, the ions were quantified by ICP-OES. The limits of detection are 21 pg.mL(-1) for Co(II), and 19 pg.mL(-1) for Sn(II). The preconcentration factors are 100 for both ions. The sorption capacities of the sorbent are 35.8 mg.g(-1) for Co(II) and 29.6 mg.g(-1) for Sn(II). The method was applied to the analysis of certificated reference materials and gave >= 95% recoveries with low RSDs. It was also successfully applied to the quantification of Co(II) and Sn(II) in spiked environmental and food samples.
Characterization and pathogenicity of Pythium-like species associated with root and collar rot of kiwifruit in Turkey
(In Plant Disease, 2021) Derviş, Sibel; Özer, Göksel; Karaca, Gürsel; Erper, İsmail; Derviş, Sibel
During the period of June to October in 2018, a widespread decline was observed on kiwifruit vines in the vineyards located in Altınordu, Fatsa, and Perşembe districts of Ordu province. The symptoms were associated with reddish-brown rots expanding from the root to the collar with sparse off-color foliage. Based on the percentage of the total infected samples across 18 vineyards, the most common oomycete species were Globisporangium intermedium (37.1%), Phytopythium vexans (34.3%), G. sylvaticum (14.3%), G. heterothallicum (11.4%), and Pythium dissotocum (2.9%). The morphological identification of isolates was confirmed based on partial DNA sequences containing the nuclear rDNA internal transcribed spacer region (rDNA ITS) and the mitochondrial cytochrome c oxidase subunit II (coxII) gene. The optimum growth temperature and the optimum pH of 5 species ranged from 22.98 to 28.25°C and 5.67 to 8.51, respectively. Pathogenicity tests on the seedlings of kiwifruit cv. Hayward revealed significant differences in virulence among isolates. Phytopythium vexans and G. sylvaticum isolates caused severe root and collar rot resulting in seedling death, while G. heterothallicum and G. intermedium isolates had relatively lower virulence. All Globisporangium spp. and P. vexans isolates significantly decreased plant growth parameters (plant height, shoot and root dry weights and root length); however, P. dissotocum caused very mild symptoms and did not affect these parameters of growth. To our knowledge, this is the first study reporting G. sylvaticum, G. heterothallicum, and G. intermedium causing root and collar rot on kiwifruit not only in Turkey but also in the world.
Comparative and competitive adsorption of gaseous toluene, ethylbenzene, and xylene onto natural cellulose-modified Fe3O4 nanoparticles
(ScienceDirect, 2022) Ece, Mehmet Şakir; Kutluay, Sinan
Many industrial processes produce volatile organic compound (VOC) pollutants within multicomponent systems. Therefore, exploring the comparative and competitive adsorption of VOCs is of both practical and scientific interest. This study elucidates the adsorption behavior of gaseous toluene, ethylbenzene, and xylene (TEX) targeted as VOCs onto natural cellulose-modified Fe3O4 (NC-Fe3O4) nanoparticles (NPs) both individually and in multicomponent systems for the first time in the literature. The characterization of NC-Fe3O4 synthesized via co precipitation method was carried out with analysis techniques including BET, SEM, EDS, FTIR, and TGA-DTA. The adsorption capacities of TEX as a single-component onto NC-Fe3O4 (for 20 mg L-1 TEX inlet concentration) were found as 477, 550, and 578 mg g(-1), respectively. In contrast, with TEX in a binary-component system, the adsorption capacity of the T (for 20 mg L-1 T with 10 mg L-1 E and 10 mg L-1 X, respectively) decreased by approximately 43% and 50% for the binary-mixtures of T-E and T-X, respectively, due to competition with E and X for adsorption sites. Similarly, the adsorption capacity of the E (for 20 mg L-1 E with 10 mg L-1 X) decreased by approximately 46% due to competition with the X for adsorption sites. With TEX in a ternary-component system, the adsorption capacity of the X remained consistent, indicating its competitive dominance over the E and T. The adsorption capacity of NC-Fe3O4 followed the order of X > E > T in the ternary-component system, which agrees with the adsorption results for the single-component system. The adsorption mechanism of TEX was explained by fitting the adsorption data to diverse kinetic and isotherm models. The NC-Fe3O4 with a superior performance in terms of both reuse efficiency and adsorption capacity, could be used as a promising and renewable adsorbent for efficient treatment of VOC pollutants. The findings of the current study will contribute to a better understanding of the comparative and competitive adsorption behaviors among different VOC pollutants in relation to a given adsorbent.
Composition, pressure, and temperature of the mantle source region of quaternary nepheline-basanitic lavas in Bitlis Massif, Eastern Anatolia, Turkey: A consequence of melts from Arabian lithospheric mantle
(Elsevier, 2019) Mercan, Çağrı; Özdemir, Yavuz; Oyan, Vural; Atakul Özdemir, Ayşe
The Quaternary (0.66–0.63 Ma) nepheline basanites (ne - basanite) are the firstly observed volcanic products of Arabia-Eurasia collision on Bitlis Pötürge Massif. They composed of clinopyroxene, olivine, Ti-magnetite, Cr spinel, and nepheline. The forsterite compositions of olivines range between 73 and 83%, calcic clinopyroxenes show modest variations in Wo48–57-En37–45-Fs5–7 and nephelines occur as minor minerals within the networks of other groundmass minerals. They are characterized by low SiO2 (40.16–41.96 wt%), high MgO contents (8.54–9.73 wt%) and similar Srsingle bondNd isotopic compositions with Arabian Plate volcanics. Mineral and whole rock thermobarometry yield crystallization pressure and a temperature range between 8 and 20 kbar and 1301 °C – 1035 °C respectively. Lavas have high Mg-number (>0.58), high Cr and Ni contents and strong LREE enrichment but depletion in Rb, K, and Pb. Trace elements together with Sr isotopic compositions inferred negligible assimilation of the local upper crustal material. The calculated average pressure and temperature of mantle melting for ne-basanites is 2,85 kbar and 1353 °C respectively. FC3MS (wt% FeO/CaO-3*MgO/SiO2) parameter and melting models using REE data reveal Çatak basanites are products of amphibole and phlogopite bearing metasomatised lithospheric mantle in garnet stability field. They seem to originated from depths of ~ 85 km which corresponds to the base of the Arabian lithosphere in the region.
A comprehensive review on detection of cyber-attacks: Data sets, methods, challenges, and future research directions
(ScienceDirect, 2022) Ahmetoglu, Huseyin; Das, Resul
Rapid developments in network technologies and the amount and scope of data transferred on networks are increasing day by day. Depending on this situation, the density and complexity of cyber threats and attacks are also expanding. The ever-increasing network density makes it difficult for cyber-security professionals to monitor every movement on the network. More frequent and complex cyber-attacks make the detection and identification of anomalies in network events more complex. Machine learning offers various tools and techniques for automating the detection of cyber attacks and for rapid prediction and analysis of attack types. This study discusses the approaches to machine learning methods used to detect attacks. We examined the detection, classification, clustering, and analysis of anomalies in network traffic. We gave the cyber-security focus, machine learning methods, and data sets used in each study we examined. We investigated which feature selection or dimension reduction method was applied to the data sets used in the studies. We presented in detail the types of classification carried out in these studies, which methods were compared with other methods, the performance metrics used, and the results obtained in tables. We examined the data sets of network attacks presented as open access. We suggested a basic taxonomy for cyber attacks. Finally, we discussed the difficulties encountered in machine learning applications used in network attacks and their solutions.
Ecofriendly Synthesis of Silver Nanoparticles Using Ananas comosus Fruit Peels: Anticancer and Antimicrobial Activities
(Hindawi, 2021) Keskin, Cumali; Baran, Ayşe; Baran, Mehmet Fırat; Huseynova, Irada; Khalilov, Rovshan; Eftekhari, Aziz; Irtegun-Kandemir, Sevgi; Kavak, Deniz Evrim
Metallic nanoparticles are valuable materials and have a range of uses. Nanoparticles synthesized from plant wastes by environment-friendly methods have attracted the attention of researchers in recent years. Also, the advantages of biological resources and synthesis methods are attracting attention. In this study, silver nanoparticles were synthesized from Ananas comosus fruit peels using ecofriendly method steps. The characterization of the particles obtained was determined by using a UV-visible spectrophotometer (UV-Vis.), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction diffractometer (XRD), Fourier scanning electron microscope (FESEM), and transmission electron microscopy (TEM). The nanoparticles showed maximum absorbance at 463 nm, measuring 11.61 in crystal nanosize, and presented spherical in appearance. An antimicrobial activity test was determined with the minimum inhibition concentration (MIC) method. The nanoparticles showed promising inhibitory activity on the Gram-positive and Gram-negative pathogen microorganisms (Escherichia coli ATCC25922, Staphylococcus aureus ATCC29213, Bacillus subtilis ATCC11774, Pseudomonas aeruginosa ATCC27833 bacteria, and Candida albicans yeast) at low concentrations. The cytotoxic and growth inhibitory effects of silver nanoparticles on different cancer cell lines were examined via the MTT assay. © 2021 Ayşe Baran et al.
First report of binucleate Rhizoctonia AG-F causing stalk and root rot of corn (Zea mays) in Turkey
(2019) Derviş, Sibel; Çiftçi, Osman; Derviş, Sibel; Ulubaş Serçe, Çiğdem
Maize or sweet corn (Zea mays L.) is one of the most widely grown and important cereal crops in terms of its area coverage and contribution to total food grains production in the world. In Turkey, approximately 640,000 ha Q:2 of land is under maize cultivation producing 5.9 million metric tons of grain. In Turkey, S¸ anlıurfa is the third largest province for corn cultivation after Adana and Mardin. In the summer of 2018, plants with suppressed growth owing to a root and stalk rot were observed in a corn field (37°27957.80N, 39°26928.90E) with an area of 8 ha located in Karakeçi neighborhood of Siverek (northern S¸ anlıurfa). Approximately 8.8% of the plants were affected. Observed symptoms started with chlorosis of the leaves followed by brown to dark-brown discoloration or rapid death of the upper leaves or whole plant. When the stalk and crown tissues were split longitudinally, we observed a brown to black dry rot or necrosis throughout the central pith and internal tissues of the stalk and crown, which resulted in a hollow stem. Affected plants showed varying degrees of necrosis on roots and crowns, and rotted roots. Plants with stalk rot easily lodged, or bent in severe cases. Isolations were performed from the margin of symptomatic stalk piths, crowns, and secondary and tap roots on potato dextrose agar (PDA) amended with streptomycin sulfate (100 ppm). Fungal colonies recovered were yellowish-gray with a powdery texture. The fungal isolates were preliminarily identified as Rhizoctonia sp. on the basis of colony morphology and typical hyphal branching pattern (i.e., hyphal ramification angles of ;90°, basal constriction, and a septum next to the lateral hyphae) (Sneh et al. 1991). Nuclear staining with a 1% Safranin O and 3% KOH (Bandoni 1979) and examination under light microscopy at ×400 magnification confirmed that hyphal cells of all isolates had two nuclei per cell (binucleate), belonging to the teleomorphic genus Ceratobasidium. No sclerotia were formed after 20 days on PDA. The genomic DNA of two isolates was extracted, and the partial internal transcribed spacer (ITS) 1, complete 5.8S ribosomal RNA gene, and partial ITS2 region of the nuclear rDNA was amplified by using the primers ITS6/ITS4. The nucleotide sequences obtained (GenBank accession nos. MK442087 and MK442088) had 100 and 99% identity, respectively, with many sequences of binucleate Rhizoctonia AG-F subgroup in NCBI database, including KT265714 and KT265715 isolated from ginger and taro in China (Dong et al. 2017), thus confirming the morphological identification. Pathogenicity tests were performed on 3-week-old healthy potted seedlings of Z. mays ‘Pioneer 2105’. Twenty plants were inoculated by placing three 1-cm-diameter mycelial plugs from 5-day-old PDA cultures of a representative isolate near the crown of plants. Fifteen plants inoculated with only PDA plugs served as controls. The plants were maintained in a growth chamber at 25 ± 1°C and 95% relative humidity with a 16-h/8-h (light/dark) photoperiod. All inoculated plants showed extensive necrosis on the roots and crown, resulting in growth reduction. The symptoms observed 15 days after inoculation were similar to those found in the commercial field. Control plants remained healthy. Binucleate Rhizoctonia was reisolated from symptomatic tissues of inoculated plants, completing Koch’s postulates. To our knowledge, this is the first report of binucleate Rhizoctonia AG-F causing stalk, crown, and root rot on Z. mays in the world. The finding of this pathogen on corn in Turkey needs to be considered when designing disease management programs for corn production.
First report of Neoscytalidium dimidiatum causing black canker and root rot of walnut in Turkey
(2019) Derviş, Sibel; Türkölmez, Şahimerdan; Çiftçi, Osman; Ulubaş Serçe, Çiğdem; Dikilitaş, Murat
Walnut (Juglans regia L.) is commercially important with about 87,670 ha grown in Turkey, the fourth largest producer worldwide. During summer 2018, unfamiliar and serious decline symptoms associated with stem and branch cankers were observed in walnut trees in two orchards in S¸ anlıurfa Province, Southeastern Anatolia Region. In a 3-year-old orchard of 450 trees (cv. Chandler) in Kayseri, Siverek District, about 62% of trees had deep, large, and black cankers in the trunks and on main branches, drastically reduced tree vigor, and yellowing, wilting, and browning of the leaves, followed by leaf drop. In a 12-year-old orchard with 30 trees (cv. Kaman), in Yaylak, Bozova District, 40% of trees had similar symptoms. Symptoms were first noticed in trunks. Bark cracks, cankers in trunks, and dark discoloration or a black sooty, dusty mass of fungal spores under peeling bark on the trunk and main branches were the most striking symptoms. Deep cankers expanded longitudinally, extending along trunks and into the phloem of the trees, which consequently died, and occasionally laterally extending into the sapwood. Declining trees had dry root rot symptoms, with black necrosis on the surface, and under the cracked and coarse bark extending from the taproot and some large roots to the crown, and black rot and loss of fine roots. Samples were taken from under the bark of trunk cankers, crown tissues, and root tissues of five trees per Q:1 orchard. The sections of samples were surface sterilized in 2% NaOCl for 2 min and rinsed twice in sterile distilled water, blotted dry with sterilized filter paper, placed on PDA, and incubated at 28°C. A fungus with identical cultural characteristics was consistently isolated. On PDA, the mycelium growth was white and then turned black with age. Rapidly growing colonies (average, 40 mm/day) produced mycelia that disarticulated into 0- to 1-septate, cylindrical-truncate or rod-shaped, thick-walled, hyaline to brown arthroconidia occurring singly or in arthric chains and averaged 9.6 ± 3.7 × 5.5 ± 1.6 μm with a length/width ratio of 1.79. These characteristics were consistent with the description of the arthric synanamorph of Q:3 Neoscytalidium dimidiatum (Penz.) Crous & Slippers (Crous et al. 2006). The rDNA internal transcribed spacer (ITS) and large subunit (LSU) genes of two single conidial isolates (one from under bark tissues; one from root tissues) were amplified with ITS6/ITS4 and NL1/NL4 primer pairs, respectively, and the amplicons sequenced. The ITS and LSU sequences deposited in GenBank (ITS, MK430050 and MK430051; LSU, MK430056 and MK430057) had 100% identity with many sequences of N. dimidiatum, including recently available ones (T¨urk¨olmez et al. 2019; ITS, MH114591; LSU, MH114592), in line with the morphological features. Pathogenicity tests were performed on 20 replicates of 1-year-old container-grown J. regia ‘Chandler’ seedlings with a N. dimidiatum isolate by removing a 5-mm-diameter bark plug from the stem with a cork borer and placing an equivalent-sized 7-day-old culture disc of N. dimidiatum onto the exposed vascular cambium. The wound was covered with wet, autoclaved cotton wool and sealed with Parafilm. Treated plants were maintained in a growth chamber with a 16/8-h light/dark photoperiod at 26°C and 55% RH and watered on demand. Within 3 weeks, average lesion lengths under the bark of all inoculated stems were >150 mm, and the lesions were covered with a black sooty layer. Leaf blight was also observed, similar to naturally affected trees. Control plants remained healthy. N. dimidiatum was reisolated only from lesions of inoculated stems, fulfilling Koch’s postulates. In Turkey, N. dimidiatum has been reported as a destructive new blight of tomato (T¨urk¨olmez et al. 2019) and canker, shoot blight, and root rot of pistachio (Dervis¸ et al. 2019). This is the first report of N. dimidiatum infection of walnuts in Turkey. By the end of 2018, all symptomatic trees had died. Recent occurrence of this severe disease suggests it could have a significant potential for limiting walnut production.
Fullerene C-60 functionalized gamma-Fe2O3 magnetic nanoparticle: Synthesis, characterization, and biomedical applications
(TAYLOR & FRANCIS LTD, 2016) Kilinc, Ersin
Hybrid magnetic nanoparticles composed from C-60 fullerene and -Fe2O3 were synthesized by hydrothermal method. XRD, FT-IR, VSM, SEM, and HR-TEM were employed for characterizations. The magnetic saturation value of C-60--Fe2O3 magnetic nanoparticles was 66.5 emu g(- 1). Concentration of Fe in nanoparticles asdetermined by ICP-OES was 40.7% Fe. Particle size of C-60--Fe2O3 magnetic nanoparticles was smaller than 10 nm. Maximum adsorption capacity of C-60--Fe2O3 for flurbiprofen, a non-steroidal anti-inflammatory drug, was calculated from Langmuir isotherm as 142.9 mg g(- 1).
gamma-Fe2O3 magnetic nanoparticle functionalized with carboxylated multi walled carbon nanotube for magnetic solid phase extractions and determinations of Sudan dyes and Para Red in food samples
(ELSEVIER SCI LTD, 2018) Kilinc, Ersin; Celik, Kadir Serdar; Bilgetekin, Havin
Hybrid nanostructures composed of gamma-Fe2O3 (maghemite) and carboxylated-multi walled carbon nanotube (cMWCNT) were used for the magnetic solid phase extractions and determination of Sudan I, II, III, IV, Para Red, Sudan Black B and Sudan Red 7B in chili products. High performance liquid chromatography (HPLC) was employed for the measurements. Limit of quantification (LOQ) values were found in the range 0.44-2.82 ng mL(-1) for analytes. The best extraction parameters were determined as pH 8.0, 40 mg of magnetic nanoparticle, 4.0 min of contact time, 0.3 mL desorption by acetonitrile. The samples were dissolved in acetone-dichloromethane-methanol (3: 2: 1, v/v/v) and diluted with acetonitrile-methanol (v/v; 80: 20) before the method was applied. Concentrations of Sudan dyes and Para Red were determined in four samples of chili powder from less than LOQ to 31.21 +/- 1.6 ng g(-1), two samples of chili tomato sauces (lower than LOQ) and two samples of ketchup (lower than LOQ).
Highly improved solar cell efficiency of Mn-doped amine groups-functionalized magnetic Fe3O4@SiO2 nanomaterial
(Wiley Online Library, 2021) Kutluay, Sinan; Horoz, Sabit; Şahin, Ömer; Ekinci, Arzu
Herein, magnetic Fe3O4@SiO2 nanomaterial functionalized with amine groups (Fe3O4@SiO2@IPA) doped with manganese (Mn) was prepared, characterized and used for solar cell application. Fe3O4@SiO2@IPA-Mn was prepared via the co-precipitation and sol-gel techniques. Energy-dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) measurements were performed to examine the structure of Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@IPA and Fe3O4@SiO2@IPA-Mn. General morphology and textural properties of the prepared magnetic nanomaterials were clarified by Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM). In addition, Ultraviolet-visible (UV-Vis) spectroscopy and thermal gravimetric analysis (TGA) were used to have a knowledge about the energy band gap and thermal behavior of the prepared magnetic nanomaterials. The energy band gap of Fe3O4@SiO2@IPA with spinel structure was determined as approximately 2.48 eV. It was understood that Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@IPA showed type IV-H3 hysteresis cycle according to IUPAC. From the BET data, it was determined that the specific surface areas of Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@IPA were 60.85, 28.99 and 40.41 m(2)/g, respectively. The pore size distributions of Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@IPA were calculated as 8.55, 1.53 and 1.70 nm, respectively, by the BJH method. Also, it was observed that the dominant pore widths of Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@IPA were calculated similar to 5.58, similar to 0.88 and similar to 17.92 nm, respectively, by the DFT method. Au/CuO/Fe3O4@SiO2@IPA-Mn/ZnO/SnO2: F solar cell device was created using existing Fe3O4@SiO2@IPA-Mn as a buffer layer. The power conversion efficiency (%) of Fe3O4@SiO2@IPA-Mn based solar cell device was calculated as 2.054. This finding suggest that Fe3O4@SiO2@IPA-Mn can be used as a promising sensitizer in solar cell technology. Moreover, in this study, the effectiveness of the modification of manganese (one of the transition metals, which is cheap and easily available) with magnetic nanomaterials in the use of solar cell technology was demonstrated for the first time.
In situ atom trapping of Bi on W-coated slotted quartz tube flame atomic absorption spectrometry and interference studies
(PERGAMON-ELSEVIER SCIENCE LTD, 2013) Kilinc, Ersin; Bakirdere, Sezgin; Aydin, Firat; Ataman, O. Yavuz
Analytical performances of metal coated slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) and slotted quartz tube in situ atom trapping flame atomic absorption spectrometry (SQT-AT-FAAS) systems were evaluated for determination of Bi. Non-volatile elements such as Mo, Zr, W and Ta were tried as coating materials. It was observed that W-coated SQT gave the best sensitivity for the determination of Bi for SQT-FAAS and SQT-AT-FMS. The parameters for W-coated SQT-FAAS and W-coated SQT-AT-FAAS were optimized. Sensitivity of FAAS for Bi was improved as 4.0 fold by W-coated SQT-FAAS while 613 fold enhancement in sensitivity was achieved by W-coated SQT-AT-FAAS using 5.0 min trapping with respect to conventional FAAS. MIBK was selected as organic solvent for the re-atomization of Bi from the trapping surface. Limit of detection values for W-coated SQT-FAAS and W-coated SQT-AT-FAAS was obtained as 0.14 mu g mL(-1) and 0.51 ng mL(-1), respectively. Linear calibration plot was obtained in the range of 2.5-25.0 ng mL(-1) for W-coated SQT-AT-FAAS. Accuracy of the W-coated SQT-AT-FAAS system was checked by analyzing a standard reference material, NIST 1643e. (C) 2013 Elsevier B.V. All rights reserved.
Investigation of Antimicrobial and Cytotoxic Properties and Specification of Silver Nanoparticles (AgNPs) Derived From Cicer arietinum L. Green Leaf Extract
(FRONTIERS, 2022) Keskin, Cumali; Hatipoğlu, Abdulkerim; Baran, Ayşe; Baran, Mehmet Fırat
Using biological materials to synthesize metallic nanoparticles has become a frequently preferred method by researchers. This synthesis method is both fast and inexpensive. In this study, an aqueous extract obtained from chickpea (Cicer arietinum L.) (CA) leaves was used in order to synthesize silver nanoparticles (AgNPs). For specification of the synthesized AgNPs, UV-vis spectrophotometer, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), electron dispersive X-ray (EDX), and zeta potential (ZP) analyses data were used. Biologically synthesized AgNPs demonstrated a maximum surface plasmon resonance of 417.47 nm after 3 h. With the powder XRD model, the mean crystallite dimension of nanoparticles was determined as 12.17 mm with a cubic structure. According to the TEM results, the dimensions of the obtained silver nanoparticles were found to be 6.11–9.66 nm. The ZP of the electric charge on the surface of AgNPs was measured as −19.6 mV. The inhibition effect of AgNPs on food pathogen strains and yeast was determined with the minimum inhibition concentration (MIC) method. AgNPs demonstrated highly effective inhibition at low concentrations especially against the growth of B. subtilis (0.0625) and S. aureus (0.125) strains. The cytotoxic effects of silver nanoparticles on cancerous cell lines (CaCo-2, U118, Sk-ov-3) and healthy cell lines (HDF) were revealed. Despite the increase of AgNPs used against cancerous and healthy cell lines, no significant decrease in the percentage of viability was detected. Copyright © 2022 Baran, Fırat Baran, Keskin, Hatipoğlu, Yavuz, İrtegün Kandemir, Adican, Khalilov, Mammadova, Ahmadian, Rosić, Selakovic and Eftekhari.
Investigation of the antibiotic resistance and biofilm-forming ability of Staphylococcus aureus from subclinical bovine mastitis cases
(ELSEVIER SCIENCE INC, 2016) Demir, Cemil; Demir, Cemil
A total of 112 Staphylococcus aureus isolates obtained from subclinical bovine mastitis cases were examined for antibiotic susceptibility and biofilm-forming ability as well as genes responsible for antibiotic resistance, biofilm-forming ability, and adhesin. Antimicrobial susceptibility of the isolates were determined by disk diffusion method. Biofilm forming ability of the isolates were investigated by Congo red agar method, standard tube method, and microplate method. The genes responsible for antibiotic resistance, biofilm-forming ability, and adhesion were examined by PCR. Five isolates (4.5%) were identified as methicillin-resistant Staph. aureus by antibiotic susceptibility testing and confirmed by mecA detection. The resistance rates to penicillin, ampicillin, tetracycline, erythromycin, trimethoprim-sulfamethoxazole, enrofloxacin, and amoxicillin-clavulanic acid were 45.5, 39.3, 33, 26.8, 5.4, 0.9, and 0.9%, respectively. All isolates were susceptible against vancomycin and gentamicin. The blaZ (100%), tetK (67.6%), and ermA (70%) genes were the most common antibiotic-resistance genes. Using Congo red agar, microplate, and standard tube methods, 70.5, 67, and 62.5% of the isolates were found to be biofilm producers, respectively. The percentage rate of icaA, icaD, and bap genes in Staph. aureus isolates were 86.6, 86.6, and 13.4%, respectively. The adhesion molecules fnbA, can, and clfA were detected in 87 (77.7%), 98 (87.5%), and 75 (70%) isolates, respectively. The results indicated that Staph. aureus from sublinical bovine mastitis cases were mainly resistant to beta-lactams and, to a lesser extent, to tetracycline and erythromycin. Also, biofilm- and adhesion-related genes, which are increasingly accepted as an important virulence factor in the pathogenesis of Staph. aureus infections, were detected at a high rate.
Investigations of Hg(II) and Pb(II) tolerance, removal and bioaccumulation and their effects on antioxidant enzymes on thermophilic Exiguobacterium profundum
(Human and Ecological Risk Assessment, 2020) Kılınç, Ersin; Akkoyun, Mahire Bayramoğlu; Özdemir, Sadin
Hg(II) and Pb(II) tolerance, removal, bioaccumulation and effects on antioxidant enzymes of thermophilic Exiguobacterium profundum were investigated. The results indicated that Hg(II) was more toxic than Pb(II) to E. profundum. E. profundum was also more tolerant in solid medium than in liquid medium for Pb(II) and Hg(II). The bacterial growth was not significantly influenced at 1.0 and 2.5 mg/L Pb(II) and Hg(II) for 24 h. The highest Hg(II) and Pb(II) bioaccumulation amounts were determined as 37.56 and 54.35 mg metal/dried bacteria, respectively. Bioaccumulation capacities of the cell membrane of E. profundum for Hg(II) and Pb(II) were determined. The different concentrations of Pb(II) and Hg(II) enhanced the SOD and CAT enzymes. In addition, variations of the surface macrostructure and the functionality of E. profundum after the interaction with Hg(II) and Pb(II) were investigated by the scanning electron microscope (SEM) and the Fourier transform infrared spectroscopy (FT-IR), respectively. This investigation obviously showed that thermophilic E. profundum can also be applied for removal and recovery of toxic metals from industrial wastewater. Clearly, a further investigation should be utilized by thermophilic microorganisms. According to antioxidant enyzme activities, E. profundum can be also used as a bioindicator for the detection of toxic metal pollution in natural water samples.
Kinetic and isotherm investigation into the removal of heavy metals using a fungal-extract-based bio-nanosorbent
(Environmental Technology and Innovation, 2020) Yıldırım, Ayfer; Acay, Hilal; Baran, Mehmet Fırat
Adsorption is very economical and environmentally friendly method that is commonly accepted as a promising technique for the removal of heavy metals. In this study a fungal-extract-based (FE-CB) bio-nanosorbent was prepared and used as an efficient biosorbent for the removal of heavy metals, namely Cu(II) and Ni(II), from aqueous solutions. FE-CB was characterized by scanning electron microscope, Brunauer–Emmett–Teller surface area and porosity analyzer, Fourier transform infrared, x-ray diffraction, differential scanning calorimeter, thermalgravimetric analysis and zeta potential. The Brunauer–Emmett–Teller surface area, pore volume and average pore diameter of FE-CB were 7.43 m2/g, 0.060 cm3/g, and 2.82 nm, respectively. The adsorbtion properties of FE-CB onto both Cu(II) and Ni(II) were investigated in terms of biosorbent dosage, temperature, initial concentration of Cu(II) and Ni(II) ions, pH and contact time in the batch experiments. The dependence of the biosorption mechanism on pH was revealed and the optimum pH was determined as 6 for Ni(II) and 5 for Cu(II). The Langmuir and Freundlich isothermal models and the kinetic Pseudo-first-order and Pseudo-second-order kinetic models were used to describe the adsorption performance of FE-CB. The activation energy was calculated by pseudo-second-order rate constants. In addition, thermodynamic parameters, standard Gibbs free energy, standard enthalpy and standard entropy were analyzed using the (Van't Hoff equation). The biosorption process was found to be spontaneous, favorable and endothermic.
Magnetic solid phase extractions of Co(II) and Hg(II) by using magnetized C-micaceus from water and food samples
(ELSEVIER SCI LTD, 2019) Ozdemir, Sadin; Mohamedsaid, Siham Abdullah; Kilinc, Ersin; Soylak, Mustafa
A new bio-MSPE sorbent based on the use of C. micaceus and gamma-Fe2O3 magnetic nanoparticle was prepared for the preconcentrations of Co(II) and Hg(II). Critical parameters including pH, flow rate, quantity of C. micaceus, quantity of gamma-Fe2O3 magnetic nanoparticle, eluent (type, concentration and volume), sample volume, and foreign ions were examined. Surface structure and variations after interaction with Co(II) and Hg(II) of bio-MSPE sorbent were investigated by FT-IR, SEM, and EDX. The impact of bio-MSPE column reusage was also tested. The biosorption capacities were determined as 24.7 mg g(-1) and 26.2 mg g(-1), respectively for Co(II) and Hg(II). Certified reference materials were utilized to find out the accuracy of the prepared bio-MSPE method. This novel bio-MSPE method was accomplished by being applied to real food and water samples. In particular, it will be possible to make use of C. micaceus as new alternatives, in environmental biotechnology applications.
New disease caused by Neoscytalidium dimidiatum devastates tomatoes (Solarium lycopersicum) in Turkey
(ELSEVIER SCI LTD, 2019) Turkolmez, Sahimerdan; Dervis, Sibel; Ciftci, Osman; Serce, Cigdem Ulubas; Dikilitas, Murat
A novel disease of tomato (Solarium lycopersicum L.) was observed in the Southeast Anatolia Region of Turkey. Symptoms were blight of all aerial parts of the plant, including stems, branches, leaves, petioles, flowers and fruits, defoliation, root rot, inner stem necrosis, and plant death. The disease was found in 13.9% of surveyed fields, with an incidence varying from 3% to nearly 75% (average 21.2%) of the plants in symptomatic fields. The average severity of blight on stem in fields with the symptomatic plant surveyed was 1.4%. A Botryosphaeriaceae species, identified as Neoscytalidium dimidiatum (Penz.) Crous & Slippers using morphological and cultural features, was consistently isolated from symptomatic roots, inner stems, and blighted leaves, shoots, stems, fruits and flowers. The partial nucleotide sequence data for three gene loci, including nuclear rDNA internal transcribed spacer (ITS), large subunit (LSU) genes and the translation elongation factor 1-alpha (TEF-1 alpha), confirmed the morphological identification. Furthermore, sequence data of actin genes from N. dimidiatwn was, for the first time, deposited to the GenBank. Koch's postulates were fulfilled by testing the susceptibility of different tomato tissues (leaves, stems, inner stems and roots of tomato seedlings, and detached tomato fruits and flowers) to N. dimidiatum inoculation. To our knowledge, this is the first report of N. dimidiatum on tomato.
O-carboxymethyl chitosan Schiff base complexes as affinity ligands for immobilized metal-ion affinity chromatography of lysozyme
(ELSEVIER SCIENCE BV, 2018) Alacabey, İhsan; Baran, Talat; Erdönmez, Demet; Aksoy, Neşe Hayat; Alacabey, İhsan; Menteş, Ayfer; Odabaşı, Mehmet
We synthesized Ni2+-attached O-Carboxymethyl chitosan Schiff base complexes embedded composite cryogels (Ni2+-O-CMCS-CCs) by means of polymerization of gel-forming precursors at subzero temperatures. Prepared affinity cryogel showed excellent adsorption performance for lysozyme selected as model protein to test adsorption parameters, demonstrating an adsorption capacity of 244.6 mg/g (15.3 mg/g for Ni2+ minus O-CMCS-CCs), with fast adsorption equilibrium within 30 min and good reversibility. The performance of Ni2+-O-CMCS-CCs for lysozyme was also evaluated by SDS-PAGE, and a purification efficiency of 86.9% with 89.5% purification yield was determined. The swelling test, FT-IR, and SEM analysis were carried out for the characterization of Ni2+-O-CMCS-CCs. At the end of 35 adsorption-desorption cycles, there was no significant change in the adsorption capacity. (C) 2018 Elsevier B.V. All rights reserved.

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