Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7755
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Article Citation - WoS: 3Citation - Scopus: 8Way-Finding Strategies of Blind Persons in Urban Scale(John Wiley and Sons Inc., 2017) Kan Kılıç, Didem; Doğan, FehmiThe aim of this study was to determine whether urban environments with different prominent sensory inputs have an impact on the way-finding strategies of blind people and to identify these impacts, where applicable. We specifically investigated how blind people use their senses to compensate for the lack of visual information and how the priority of senses changes according to the urban context. The participants of the study consisted of nine congenitally blind individuals and the study took place in two urban settings: a dense urban district, Kemeralti district in İzmir; and an urban park, the İzmir Fair Park. During the learning phase, a first trial along the selected routes was conducted for each participant individually along with one of the researchers. In the test phase, the participants were requested to re-walk the route and verbally report the environmental cues they attended to. The participants’ verbal reports were recorded and transcripts of the recordings were coded according to the environmental sensory inputs. In addition, the short-term memory of each participant was also evaluated. The results show that the characteristics of the urban environment seem to have an impact on way-finding strategies of blind individuals. It was found that the sound of the city and the echo from the environment are the most important factors for blind participants in the dense urban environment. Environmental boundaries provided echoes and gave a sense of enclosure that helped them orient themselves, whereas, in the park environment, the sense of enclosure was not enhanced due to a lack of boundaries in the environment.Article Effects of Reactor Pressure and Inlet Temperature on N-butane/Dimethyl Ether Oxidation and the Formation Pathways of the Aromatic Species(John Wiley and Sons Inc., 2016) Bekat, Tuğçe; İnal, FikretOxidation of n-butane/dimethyl ether (DME)/O2/Ar system was studied by chemical kinetic modeling in a tubular reactor operated adiabatically and at constant pressure. Effects of the reactor pressure on the formation of various major, minor, and trace oxidation products were investigated for two different pressures (1 and 5 atm) and at six different inlet temperature values (700, 800, 900, 1100, 1300, and 1500 K). The analysis was carried out for two different concentrations of dimethyl ether in the inlet fuel mixture (20 and 50 mol %). Higher pressure (5 atm) resulted in higher mole fractions of methane, vinylacetylene, and cyclopentadiene; and lower mole fractions of formaldehyde, acetylene, acetaldehyde, ethane, propargyl, and propane. The mole fractions of CO and CO2 were not affected considerably by the pressure change. The main formation routes of benzene were developed at two different inlet temperature values (1100 and 1300 K), and the main precursors participating in these routes were found to be propargyl, propene, and diacetylene. A skeletal mechanism was developed for the oxidation of n-butane/DME mixture from the detailed mechanism by reduction of the elementary reactions by 79%, and it was tested for accuracy by comparison with the data from the literature.Article Citation - WoS: 3Citation - Scopus: 3Genetic relationships among Eurasian Puccinellia distans genotypes(Elsevier Ltd., 2015) Bar, Cantuğ; Doğanlar, Sami; Frary, AnnePuccinellia distans (Jacq.) Parl. is a common grass species found throughout the world. It can grow in arid and saline environments as well as under toxic boron concentrations. In this work we performed sequence related amplified polymorphism (SRAP) marker analysis on 20 wild P. distans genotypes to understand the genetic relationships among different genotypes and subspecies. We tested 119 SRAP primer pairs and found that 43 were polymorphic. The molecular data were then analyzed to determine the genetic relationships and population structure of the genotypes. We were able to trace the origin of genotypes that were carried to distant locations or gathered for research purposes. We also found that geographical distance between genotypes was not an important determinant of genetic relationships as even distantly located Puccinellia genotypes were closely related. As P. distans is known to be tolerant to salinity stress and toxic mineral concentrations, the findings of this work can be used as a starting point for selection of genotypes that should be tested under such conditions.Article Citation - WoS: 2Citation - Scopus: 2Sample Collection Into Sterile Vacuum Tubes To Preserve Arsenic Speciation in Natural Water Samples(American Society of Civil Engineers (ASCE), 2013) Gündüz, Orhan; Gürleyük, Hakan; Çakır, Ayşe; Elçi, Alper; Baba, Alper; Şimşek, CelalettinThe accurate speciation analysis of arsenic is a serious concern for water quality monitoring programs. Because the preservation of sample integrity until analysis is one of the most important aspects of speciation, this study aims to compare the performance of four different sample preservation methods under diverse conditions of sample quality. Natural samples with different characteristics were collected into the following containers to study their effectiveness: (1) standard high-density polyethylene bottle with no preservative; (2) empty, sterile Vacuette tube with no preservative; (3) sterile tripotassium ethylenediaminetetraacetic acid (K3EDTA) Vacuette tube with K3EDTA additive; and (4) empty, sterile Vacuette tube with added hydrochloric acid (HCl). Known concentrations of arsenite [As(III)] were also added to each container to monitor the oxidation of As(III) to arsenate [As(V)]. The results revealed recovery ratios exceeding 95% in all containers with sterile vacuum conditions. In particular, the K3EDTA Vacuette tube yielded a recovery very close to 100% of the spiked As(III), which is known to rapidly oxidize to As(V). Overall, collecting the sample into a container under sterile vacuum conditions and using a universally accepted preserving agent such as EDTA or HCl significantly improved the preservation of the original species distribution in the water matrix studied, compared to sampling without the use of preservation methods. After validation by future research, these sterile vacuum tubes can possibly be utilized for collecting and storing samples for the routine speciation analysis of other elements such as selenium, chromium, and antimony.Article Citation - WoS: 24Citation - Scopus: 25Atmospheric Concentrations and Phase Partitioning of Polycyclic Aromatic Hydrocarbons in Izmir, Turkey(John Wiley and Sons Inc., 2011) Demircioğlu, Eylem; Sofuoğlu, Aysun; Odabaşı, MustafaAmbient air polycyclic aromatic hydrocarbon (PAH) samples were collected at a suburban (n=63) and at an urban site (n=14) in Izmir, Turkey. Average gas-phase total PAH (∑ 14PAH) concentrations were 23.5ngm -3 for suburban and 109.7ngm -3 for urban sites while average particle-phase total PAH concentrations were 12.3 and 34.5ngm -3 for suburban and urban sites, respectively. Higher ambient PAH concentrations were measured in the gas-phase and ∑ 14PAH concentrations were dominated by lower molecular weight PAHs. Multiple linear regression analysis indicated that the meteorological parameters were effective on ambient PAH concentrations. Emission sources of particle-phase PAHs were investigated using a diagnostic plot of fluorene (FLN)/(fluorine+pyrene; PY) versus indeno[1,2,3-cd]PY/(indeno[1,2,3-cd]PY+benzo[g,h,i]perylene) and several diagnostic ratios. These approaches have indicated that traffic emissions (petroleum combustion) were the dominant PAH sources at both sites for summer and winter seasons. Experimental gas-particle partition coefficients (K P) were compared to the predictions of octanol-air (K OA) and soot-air (K SA) partition coefficient models. The correlations between experimental and modeled K P values were significant (r 2=0.79 and 0.94 for suburban and urban sites, respectively, p<0.01). Octanol-based absorptive partitioning model predicted lower partition coefficients especially for relatively volatile PAHs. However, overall there was a relatively good agreement between the measured K P and soot-based model predictions. Ambient air polycyclic aromatic hydrocarbon (PAH) samples were collected at a suburban and at an urban site in Izmir, Turkey. The multiple linear regression analysis indicated that the meteorological parameters were effective on the measured ambient PAH concentrations. The results indicated that traffic emissions were the dominant PAH sources at both sites for summer and winter seasons.Article Citation - WoS: 3Citation - Scopus: 3Simulating Transient Sediment Waves in Aggraded Alluvial Channels by Double-Decomposition Method(American Society of Civil Engineers (ASCE), 2011) Tayfur, Gökmen; Singh, Vijay P.By using the double-decomposition (DD) method, this study simulates transient sediment waves caused by aggradation described by a diffusion-type partial differential equation (PDE). The DD method solves the PDE by decomposing the solution function for sediment rate into a summation of M number of components, where M stands for the order of approximation. The solution was approximated by considering only the first three terms. The model satisfactorily simulated laboratory-measured aggradation bed profiles with, on average, a mean absolute error (MAE) of 0.70 cm, a root-mean-square error (RMSE) of 0.84 cm, a mean relative error (MRE) of 1.11%, and R2=0.95. The model performance was also tested by using numerical and error-function solutions. In addition, the results obtained from application of the DD solution to hypothetical field cases were found to be theoretically compatible with what may be observed in natural streams. However, sediment wave fronts in later periods of the simulation time reached equilibrium bed levels more quickly, around in the middle section of the channel.Article Citation - WoS: 9Citation - Scopus: 11Oxidation Behavior of C-And Au-Ion Biodegradable Polymers(Institute of Electrical and Electronics Engineers Inc., 2012) Sokullu Urkaç, Emel; Öztarhan, Ahmet; Tıhmınlıoğlu, Funda; Nikolaev, Alexey; Brown, IanBiodegradable polymers are widely used in biomedical and tissue engineering applications due to their biocompatibility and hydrolysis properties in the body. However, their low surface energy and lack of functional groups to interact with the cellular environment have limited their applications for in vivo studies. Ion beam modification is a convenient method for improving the surface properties of polymeric materials for functional biomedical applications. In the work described here, vacuum arc metal ion implantation was used to modify the composition of the near-surface region of three kinds of polymerspoly(L-lactide), poly(D, L-lactide-co-glycolide), and poly(L-lactide/caprolactone)chosen as representative of biodegradable polymers. X-ray photoelectron spectroscopy analysis was used to characterize the chemical effects of these polymers after implantation with C and with Au, and the results were compared with untreated control samples. We find that oxidation behavior is brought about for certain implantation fluences, resulting in improved surface hydrophilicity. © 2011 IEEE.Article Citation - WoS: 3Citation - Scopus: 5Production of Food Grade Ss-Galactosidase From Artisanal Yogurt Strains(Taylor and Francis Ltd., 2010) Tarı, Canan; Üstok, Fatma Işık; Harsa, ŞebnemSuperior artisanal isolates of thermophilic lactic acid bacteria producing high lactic acid and β-galactosidase were isolated from traditional Turkish yogurt samples from the Toros mountain region from a highly bio-diverse environment. A full factorial statistical design, with the factors of types of strains and medium formulations under static and agitation conditions, were applied to investigate the effects on β-galactosidase and lactic acid production. Streptococcus thermophilus 95/2 and Lactobacillus delbrueckii subsp. thermophilus 77 exhibited remarkable potential as promising starter culture candidates valuable to various applications in the dairy industry. The efficiency of cell disruption methods was investigated on the extraction of intracellular β-galactosidase enzyme. Lysozyme enzyme treatment was determined as the most effective method, which resulted in approximately 1.5 and 10 times higher enzyme activity than glass bead and homogenization treatment, respectively. © Taylor & Francis Group, LLC.Article Citation - WoS: 15Citation - Scopus: 17Genetic Algorithm-Based Discharge Estimation at Sites Receiving Lateral Inflows(American Society of Civil Engineers (ASCE), 2009) Tayfur, Gökmen; Barbetta, Silvia; Moramarco, TommasoThe genetic algorithm (GA) technique is applied to obtain optimal parameter values of the standard rating curve model (RCM) for predicting, in real time, event-based flow discharge hydrographs at sites receiving significant lateral inflows. The standard RCM uses the information of discharge and effective cross-sectional flow area at an upstream station and effective cross-sectional flow area wave travel time later at a downstream station to predict the flow rate at this last site. The GA technique obtains the optimal parameter values of the model, here defined as the GA-RCM model, by minimizing the mean absolute error objective function. The GA-RCM model was tested to predict hydrographs at three different stations, located on the Upper Tiber River in central Italy. The wave travel times characterizing the three selected river branches are, on the average, 4, 8, and 12h. For each river reach, seven events were employed, four for the model parameters' calibration and three for model testing. The GA approach, employing 100 chromosomes in the initial gene pool, 75% crossover rate, 5% mutation rate, and 10,000 iterations, made the GA-RCM model successfully simulate the hydrographs observed at each downstream section closely capturing the trend, time to peak, and peak rates with, on the average, less than 5% error. The model performance was also tested against the standard RCM model, which uses, on the contrary to the GA-RCM model, different values for the model parameters and wave travel time for each event, thus, making the application of the standard RCM for real time discharge monitoring inhibited. The comparative results revealed that the RCM model improved its performance by using the GA technique in estimating parameters. The sensitivity analysis results revealed that at most two events would be sufficient for the GA-RCM model to obtain the optimal values of the model parameters. A lower peak hydrograph can also be employed in the calibration to predict a higher peak hydrograph. Similarly, a shorter travel time hydrograph can be used in GA to obtain optimal model parameters that can be used to simulate floods characterized by longer travel time. For its characteristics, the GA-RCM model is suitable for the monitoring of discharge in real time, at river sites where only water levels are observed.Article Citation - WoS: 28Citation - Scopus: 18Artificial Neural Network Prediction of Tropospheric Ozone Concentrations in Istanbul, Turkey(John Wiley and Sons Inc., 2010) İnal, FikretTropospheric (ground-level) ozone has adverse effects on human health and environment. In this study, next day's maximum 1-h average ozone concentrations in Istanbul were predicted using multi-layer perceptron (MLP) type artificial neural networks (ANNs). Nine meteorological parameters and nine air pollutant concentrations were utilized as inputs. The total 578 datasets were divided into three groups: training, cross-validation, and testing. When all the 18 inputs were used, the best performance was obtained with a network containing one hidden layer with 24 neurons. The transfer function was hyperbolic tangent. The correlation coefficient (R), mean absolute error (MAE), root mean squared error (RMSE), and index of agreement or Willmott's Index (d2) for the testing data were 0.90, 8.78 μg/m3, 11.15μg/m3, and 0.95, respectively. Sensitivity analysis has indicated that the persistence information (current day's maximum and average ozone concentrations), NO concentration, average temperature, PM10, maximum temperature, sunshine time, wind direction, and solar radiation were the most important input parameters. The values of R, MAE, RMSE, and d2 did not change considerably for the MLP model using only these nine inputs. The performances of the MLP models were compared with those of regression models (i.e., multiple linear regression and multiple non-linear regression). It has been found that there was no significant difference between the ANN and regression modeling techniques for the forecasting of ozone concentrations in Istanbul. Tropospheric ozone has adverse effects on human health and environment. Here, the next-day's maximum 1-h average ozone concentrations in Istanbul were predicted using multi-layer perceptron type artificial neural networks (MLP-ANNs). The MLP-ANNs were compared to multiple linear and multiple non-linear regression models. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.