IZTECH Research Centers Collection / İYTE Araştırma Merkezleri Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/11147/2636
Browse
9 results
Search Results
Article Citation - WoS: 3Citation - Scopus: 3Energy Performance Assessment in Terms of Primary Energy and Exergy Analyses of the Nursing Home and Rehabilitation Center(SAGE Publications Inc., 2019) Hancıoğlu Kuzgunkaya, EbruThis paper concerns with the energy analysis (based on primary energy) and exergy analysis of Narlıdere Nursing Home and Rehabilitation Center (NNHRC) in İzmir, Turkey that was chosen as a sample public building. The Center services as a nursing and rehabilitation center for the aged and it also includes a geriatric division operating as a hospital. The Center was analyzed using the actual energy consumption data derived from several energy audits. Energy efficiency (according to the primary energy ratio) and exergy efficiency of the facility were calculated to be 59% and 14%, respectively. The results have indicated that the exergy efficiencies of space heating and cooling have the lowest values compared with the other units of facility. Specific primary energy consumption and specific exergy consumption of the facility were found to be 271.91 kWh/m2 year and 290.23 kWh/m2 year, respectively. Sustainability index value of the overall NNHRC was found to be 1.621.Article Citation - WoS: 32Citation - Scopus: 30Geochemical and Hydrogeochemical Characteristics and Evolution of Kozaklı Geothermal Fluids, Central Anatolia, Turkey(Elsevier Ltd., 2019) Baba, Alper; Şener, Mehmet FurkanKozaklı is one of the most important areas of Central Anatolia in terms of geothermal potential and it is characterized by thrust and normal faults. These faults, accommodating deep circulation of hydrothermal fluids of meteoric origin, are the primary controls of the geothermal systems in this region. Chemical and isotopic composition of the hot springs and geothermal fluids was monitored throughout 2017. The surface temperature of the fluid ranges from 24.9 to 96 °C. The cold spring waters are mostly of the Ca-Mg−HCO3 type in the study area. Major element chemistry of the water reveals that the deep geothermal fluids are mostly of the Na-Ca-Cl-SO4 type while the shallow geothermal well waters are Ca-Na−HCO3 waters. Silica geothermometers suggest that the reservoir temperature ranges from 103 to 173 °C. Based on the δ18O–δD relationship, water samples have a high-altitude meteoric origin. Stable isotopic data indicate that the geothermal fluids are formed by local recharge and deep circulation of meteoric waters. The Rare Earth Elements and Yttrium (REY) composition showed that Eu, Ce and Y anomalies are related both to inheritance from geological host materials and the fractionation of these elements during water-rock interactions.Article Citation - WoS: 1Citation - Scopus: 1Triploid Induction of Green Tiger Shrimp, Penaeus Semisulcatus (de Haan, 1844) Using Temperature and Chemical Shock(John Wiley and Sons Inc., 2015) Kır, Mehmet; Tarhan, Gökhan; Okur, ÖzgürTriploidy in fertilized eggs of Penaeus semisulcatus was induced by temperature and chemical shocks. The eggs, which were obtained from the shrimp broodstock maintained at 29C, were exposed to cold temperature (8, 10, 12, and 14 C) and 6-dimetiloaminopurine (6-DMAP) concentrations (100, 150, 200, and 250 μM) for different durations (4, 6, and 8min) 9min after spawning was detected. While the highest triploidy rate of 49.7±4.5% was obtained with a 200μM 6-DMAP concentration for a duration of 8min, the best mean triploidy rate of 45.5±2.8% for cold shock was obtained at a temperature of 10 C for a duration of 8min. Temperature and 6-DMAP concentration did not have significant effect on triploidy rate (P>0.05) but shock duration had significant effect on triploidy rate for individual cold temperature shock or 6-DMAP chemical shock (P<0.05). Although longer durations of shock agent increased the rates of triploid induction, they generally had an adverse effect on hatching rates in the study.Article Citation - WoS: 83Citation - Scopus: 92Source of Arsenic Based on Geological and Hydrogeochemical Properties of Geothermal Systems in Western Turkey(Elsevier Ltd., 2012) Baba, Alper; Sözbilir, HasanTurkey is an area of complex geology with active tectonics and high geothermal potential. Especially, the western part of Turkey is a region of abundant geothermal activity. Faults accommodating the deep circulation of hydrothermal fluids of meteoric origin are the primary means by which of geothermal systems are controlled in this region. Many of the thermal activities are related to the improved dilation on the ~E-W-strikes of the graben faults. This situation serves as a suitable environment for the presence of high levels of arsenic in geothermal water resources. The highest concentrations of naturally occurring aqueous arsenic (As) are found in certain types of geothermal waters, generally those related to major graben faults. In this regard, high arsenic concentrations in geothermal resources have been detected in Western Turkey, including but not limited to Biga Peninsulla, Gediz Graben, Kucuk, and Buyuk Menderes Graben with values ranging from 1 to 1419ppb in geothermal fluids. The thermal waters have surface temperatures of up to 100°C and reservoir temperatures range from 150 to 248°C in the Menderes Graben, from 120 to 287°C in the Gediz Graben, and from 153 to 174°C in Biga Peninsula. Hydrogeochemically, the Menderes graben and Gediz Graben thermal waters are of the Na-HCO3, Ca-HCO3, and Na-SO4 types, whereas some geothermal fluids such as those of Tuzla and Kestanbol in the Biga Peninsula, Çeşme, and Urla are of the Na-Cl type.Article Citation - WoS: 105Citation - Scopus: 125Prevalence of Staphylococcal Enterotoxins, Toxin Genes and Genetic-Relatedness of Foodborne Staphylococcus Aureus Strains Isolated in the Marmara Region of Turkey(Elsevier Ltd., 2011) Aydın, Ali; Sudağıdan, Mert; Muratoğlu, KarloStaphylococcus aureus is a major foodborne pathogen and it has the ability to produce a number of extracellular toxins. We analyzed 1070 food samples obtained from retail markets and dairy farms in the Marmara Region of Turkey for the presence of S. aureus. Out of 147 isolates, 92 (62.6%) were enterotoxigenic. PCR was used to investigate the presence of staphylococcal enterotoxin genes (sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq and seu), exfoliative toxin genes (eta and etb) and the toxic - shock syndrome toxin gene (tst). The PCR results showed that 53.3% of the isolates contained staphylococcal enterotoxin-like (SEl) toxin genes (seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq and seu) which were more frequent than classical enterotoxin genes (sea to see). Furthermore, seo, sei, sem, seg, seu and sec were found in 37.0, 32.7, 30.4, 29.3, 29.3 and 27.2% of the isolates, respectively. The tst gene was detected and confirmed by DNA sequencing in 9 isolates. The presence of eta and etb were not found in the isolates. Enterotoxigenic capabilities of isolates with SEA-SEE were investigated by ELISA. Enterotoxigenic S. aureus isolates produced one to three enterotoxins, with the most frequently produced types being enterotoxin A and C. There was a correlation of 72.1% between production of a specific toxin and the presence of the respective genes. PFGE analysis was used to identify genetic-relatedness of enterotoxigenic S. aureus isolates and the results revealed that 13 groups of isolates from different or the same origin that contained the same genes showed 100% homology with indistinguishable band patterns. The other enterotoxigenic isolates showed related band patterns with 72-86% homology in sea-, 61-90% homology in sec-, 80-96% homology in seh-, and 69-96% homology in sep-positive isolates. To our knowledge, this is the first study to examine enterotoxins and related gene contents of S. aureus food isolates in the Marmara Region of Turkey.Article Citation - WoS: 3Citation - Scopus: 3Effects of Different Lipopolysaccharide Preparations on Neutrophil Function in the Fathead Minnow, Pimephales Promelas Rafinesque(John Wiley and Sons Inc., 2011) Jovanovic, B.; Baran, Ezgi; Goetz, F. W.; Palic, D.The fish innate immune response to pathogensrelies on the adequate function of neu trophilicgranulocytes (Palic´, Andreasen, Herolt, Menzel &Roth 2006). The ability of neutrophils to phago-cytose microor ganisms and cellular debris is essen-tial for normal development an d survival of animalpopulations (Segal 2005). The evaluation of neu-trophil function is valuable for assessing the healthstatus of individuals and fish populations (Smith &Lumsden 1983). Resistance of fishes to septic shockand tolerance to high concentrations of lipopoly-saccharide (LPS) was observed as a major differencebetween mammalian and fish innate immuneresponses (Berczi, Bertok & Bereznai 1966). Thisfunctional difference could be attri buted to severalcostimulatory molecules and intracellular mediatorsbeing absent in fish, but active in mammals duringresponse to LPS stimulation (Iliev, Roach, Mac-kenzie, Planas & Goetz 2005). Most fish do notpossess a Toll-like receptor (TLR) with sequencesimilarity to mammalian TLR4 (Leulier & Lemai-tre 2008) and the ones that do have no ability forTLR4 downstream signalling (Sepulcre, Alcaraz-Perez, Lopez-Munoz, Roca, Meseguer, Cayuela &Mulero 2009). Regardless of the absence andfunctionality of TLR4 and costimulatory molecules,bacterial LPS can induce a robus t inflammatorygene response in innate immune fish cells, but atconcentrations 1000-fold higher than is commonlyobserved in mammalian species ( lgmL)1vs.ng mL)1) (Palic´, Ostojic, Andreasen & Roth2007; Mackenzie, Roher, Boltan˜a & Goetz 2010).In contrast, ultrapure LPS preparations are rela-tively inactive in fish (Iliev et al. 2005).Article Citation - WoS: 20Citation - Scopus: 19Virulence Properties of Methicillin-Susceptible Staphylococcus Aureus Food Isolates Encoding Panton-Valentine Leukocidin Gene(Elsevier Ltd., 2010) Sudağıdan, Mert; Aydın, AliIn this study, three Panton-Valentine Leukocidin gene carrying methicillin-susceptible Staphylococcus aureus (MSSA) strains (M1-AAG42B, PY30C-b and YF1B-b) were isolated from different food samples in Kesan-Edirne, Turkey. These strains were characterized on the basis of MLST type, spa type, virulence factor gene contents, antibiotic susceptibilities against 21 antibiotics and biofilm formation. The genetic relatedness of the strains was determined by PFGE. In addition, the complete gene sequences of lukS-PV and lukF-PV were also investigated. All strains were found to be susceptible to tested antibiotics and they were mecA negative. Three strains showed the same PFGE band pattern, ST152 clonal type and t355 spa type. In the detection of virulence factor genes, sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq, seu, eta, etb, set1, geh and tst genes were not detected. All strains showed the positive results for α- and β-haemolysin genes (hla and hlb), protease encoding genes (sspA, sspB and aur), lukE and lukD leukocidin genes (lukED). The strains were found to be non-biofilm formers. By this study, the virulence properties of the strains were described and this is one of the first reports regarding PVL-positive MSSA strains from food. © 2010 Elsevier B.V.Article Citation - WoS: 46Citation - Scopus: 53Extracellular Enzyme Production and Enterotoxigenic Gene Profiles of Bacillus Cereus and Bacillus Thuringiensis Strains Isolated From Cheese in Turkey(Elsevier Ltd., 2009) Molva, Çelenk; Sudağıdan, Mert; Okuklu, BurcuThe aim of the present study was to investigate the biochemical characteristics, extracellular enzyme production and enterotoxigenic genes contents of 6 Bacillus cereus and 22 Bacillus thuringiensis strains, isolated from 100 cheese samples in Turkey. Crystal morphologies of B. thuringiensis strains were found either spherical (n = 12) or spherical and irregular-shaped (n = 10) by phase contrast microscopy. B. cereus and B. thuringiensis strains were found to produce extracellular enzymes, respectively: gelatinase (83% and 91%), DNase (83% and 77%), lecithinase (83% and 95%), protease on skim milk agar (100% and 100%), protease on milk agar (100% and 91%), protease on casein agar (83% and 77%), xylanase (100% and 45%), and cellulase (0% and 41%), and amylase (83% and 27%). All of the strains, except for Bt-D1, hydrolyzed Tween 20 (96%), but not Tween 80 or tributyrin. Pectinolytic activity was obtained to be the least frequent (4%). PCR analysis showed that all strains contained nheA, nheB, nheC and hblD genes. The hblA and hblC genes were present in 2 and 4 of B. thuringiensis strains, respectively. The bceT gene was detected in 1 B. cereus and 9 B. thuringiensis strains. The entFM gene was detected more frequently in B. thuringiensis (82%) than in B. cereus strains (50%). To our knowledge, this is the first report about the isolation and identification of enterotoxigenic B. cereus and B. thuringiensis strains from cheese samples in Turkey.Article Citation - WoS: 30Citation - Scopus: 36Hydrogeological Properties of Hyper-Saline Geothermal Brine and Application of Inhibiting Siliceous Scale Via Ph Modification(Elsevier Ltd., 2015) Baba, Alper; Demir, Mustafa Muammer; Koç, Gonca A.; Tuğcu, CelalScaling is a major obstacle in harnessing of geothermal energy from the geothermal resources. This paper presents a case study for inhibition of metal silicate scaling using formic acid, harvesting more energy in particular case of Tuzla Geothermal Field (TGF), located on Biga Peninsula, in the northwestern of Turkey. TGF is 5. km far from Aegean Sea and 80. km south of Çanakkale. Geothermal fluid of TGF has high salinity (EC. > 91. mS/cm) and medium temperature (reservoir temperature is 173. °C). The acidification of high-salinity brine to mitigate silicate scaling is examined. Results of the study showed that a compromise between scaling and corrosion is achieved by reducing pH of brine to <6 using 55. ppm formic acid.