Erdoğan, Zeynep | Zeydan, Özgür | Sert, Havva

Makale | 2008 | İstanbul Üniversitesi Florence Nightingale Hemşirelik Yüksekokulu Dergisi16 ( 61 ) , pp.71 - 76

Dünyanın iklimi jeolojik tarih boyunca birçok kez doğal olarak değişmiştir. Fakat, endüstri devriminden sonra fosil yakıtlarından kaynaklanan emisyonlar ve diğer sentetik sera gazlarının emisyonlarıyla artan sera etkisi nedeniyle sıcaklık kayıtlarında yükseliş trendi mevcuttur. Sera etkisi atmosferin ısı kapasitesini değiştirerek sıcaklık ve yağış anormalliklerine ve en sonunda da iklim değişikliğine neden olur. iklim değişiklinin etkileri ekosistemlerde, sosyal ve ekonomik yaşamda ve arazi kullanımıyla sınırlı olmayıp ayrıca, doğrudan ve dolaylı olarak insan sağlığı üzerine etkileri de vardır. Sıcak dalgalarına bağlı ölümler, solun . . .um ve dolaşım sistemi hastalıkları ve infeksiyon hastalıkları iklim değişikliği sonucunda ortaya çıkan sağlık sorunlarıdır. Earth's climate has changed naturally many times throughout the geological history. However, after the industrial revolution there exists a rising trend in temperature records due to increasing greenhouse effect, which is resulted from fossil fuel emissions and other synthetic greenhouse gasses emissions. Greenhouse effect changes heat capacity of atmosphere that causes temperature and precipitation anomalies and ultimately climate change. The effects of climate change will be seen in ecosystems, in social and economical life and in land use. Moreover, there are direct and indirect health effects of climate change on humans. Mortality depending on heat waves, respiratory and cardiovascular disease and infectious disease are the health problem resulted from climate change Daha fazlası Daha az

Genç, Ayten

Diğer | 2009 | Turkish Journal of Engineering and Environmental Sciences33 ( 1 ) , pp.73 - 81

The membrane potentials for asymmetric membranes where fixed charges varied linearly with position were evaluated from the numerical solutions of Nernst-Planck flux and Donnan potential equations. The evaluated membrane potentials were compared with the results obtained from the conventional TMS theory where the fixed charge concentration in the membrane was assumed to be uniform. In the comparison, the number of fixed charges was kept constant by defining an average for the fixed charge concentration. The numerical results showed that the membrane potential increased in magnitude when the distributions of fixed charges at the membr . . .ane-solution interfaces were unequal. In addition, the deviation from TMS theory increased more as the charge difference at the interfaces increased. The membrane potentials for asymmetric membranes where fixed charges varied linearly with position were evaluated from the numerical solutions of Nernst-Planck flux and Donnan potential equations. The evaluated membrane potentials were compared with the results obtained from the conventional TMS theory where the fixed charge concentration in the membrane was assumed to be uniform. In the comparison, the number of fixed charges was kept constant by defining an average for the fixed charge concentration. The numerical results showed that the membrane potential increased in magnitude when the distributions of fixed charges at the membrane-solution interfaces were unequal. In addition, the deviation from TMS theory increased more as the charge difference at the interfaces increased Daha fazlası Daha az

Genç, Ayten | Tosun, İbrahim

Makale | 2002 | Separation Science and Technology37 ( 13 ) , pp.3053 - 3064

Results from the electrofiltration of anatase (TiO2) particles in a water suspension and using three different electrode configurations are presented. The three electrode configurations studied were spot, foil, and mesh. For the first two configurations, the electric field was perpendicular to the direction of flow while for the mesh configuration it was opposite to the direction of flow. The percent gain volume filtrate and power consumption were measured for each electrode configuration. For a given percent gain volume filtrate, it was observed that the foil electrode configuration consumes the least power.

Genç, Ayten | Tosun, İbrahim

Bildiri | 2007 | American Filtration and Separations Society - 20th Annual Conference and Exposition of the American Filtration and Separations Society 20071 , pp.340 - 350

The variation in slurry concentration within the filter chamber during the startup of constant pressure filtration experiments and its effect on the cake length and filtrate volume are studied. Theoretical equations relating slurry concentration to cake length and filtrate volume are developed by using the equations of continuity together with the jump conditions at the cake-slurry interface. Comparison with the experimental values indicates that the change in slurry concentration within the filter chamber, especially during the initial stages of filtration, should be taken into consideration in the evaluation of model parameters fr . . .om experimental data Daha fazlası Daha az

Albek, Erdem Ahmet | Göncü, Serdar | Uygun, Burcu Şimşek | Albek, Mine | Avdan, Zehra Yiğit | Güngör, Ömer

Makale | 2019 | Global Nest Journal21 ( 2 ) , pp.163 - 171

Population growth, urbanization and anthropogenic activities are becoming a serious problem for water resources in Turkey, which necessitates their monitoring and maintenance of water quality. In this study, water quality was implemented in the Porsuk Stream in Inner Anatolia, Turkey. Water samples were collected at monthly intervals between the period of 2008-2010 at four selected stations. Twenty one water quality parameters were measured which are water temperature (T), pH, dissolved oxygen (DO), electrical conductivity (EC), salinity, turbidity, chloride, suspended solids, dissolved solids, organic nitrogen (Org-N), ammonium nit . . .rogen (NH3-N), nitrite nitrogen (NO2-N), nitrate nitrogen (NO3-N), total organic carbon, biological oxygen demand (BOD), chemical oxygen demand (COD), total coliform, alkalinity, orthophosphate phosphorus (PO4 3--P), total phosphorus and chlorophyll-a. The monitoring was conducted to see how the water quality changed along the stream in response to various anthropogenic activities. Besides, a paired t-test was utilized to determine the concentration differences at stations above and below the single most important point source of pollutants (Eskisehir city). Moreover, a regression model was used to establish relations between water quality parameters and flow and to estimate nonpoint source loadings. © 2019 Global NEST Printed in Greece Daha fazlası Daha az

Yıldırım, Yılmaz | Bayramoğlu, Mahmut | Tecer, Lokman Hakan | Yalçın, Gültekin

Bildiri | 2004 | AIR POLLUTION MODELING AND ITS APPLICATION XVI16 , pp.559 - 567

Air pollution continues to be a major problem in many countries. Mathematical models are useful in relating emissions to air quality under a variety of meteorological conditions and source emission concentrations over an urban area. Meanwhile, the forecasting capability of sophisticated models is limited to very large and complex terrains. In this study, adaptive neuro-fuzzy logic method has been proposed to estimate the impact of meteorological factors on SO2 pollution levels. The model forecasts satisfactorily the trends in SO2 concentration levels, with performance between 78-90%.

Genç, Ayten | Chase, George | Foos, Annabelle

Makale | 2009 | Water, Air, and Soil Pollution197 ( 01.Apr ) , pp.131 - 141

Manganese was removed from naturally polluted river sediment by applying an electrokinetic remediation technique. The sediment was alkaline and had 20% clay, which was mainly illite. The electrokinetic remediation experiments were performed by controlling pHs in the electrode cells and reverse electroosmotic flows were observed, i.e., water moved from cathode towards anode. Manganese accumulated in areas closer to cathode, however, other metals, such as copper, zinc and lead were mostly observed in the middle section of the sediment. As a result of reverse electroosmotic flow, the removal efficiencies of metals were low and the high . . .est removal efficiencies of manganese, copper and lead, were evaluated as 18%, 20% and 12%, respectively. Almost no removal of zinc was observed in all electrokinetic remediation experiments. © 2008 Springer Science+Business Media B.V Daha fazlası Daha az

Demirel Bayık, Gülçin | Altın, Ahmet

Makale | 2017 | Marine Pollution Bulletin125 ( 01.Feb ) , pp.341 - 349

The aim of the study is to select a cellulosic waste material from paper industry solid wastes and process it for sorbent production. Four different solid wastes were collected from a local paper production facility and rejects were selected due to its sorption capacity and processability. Oil sorption experiments were conducted according to the ASTM F 726-12 method. Effect of sorbent dosage, contact and dripping time, recovery of the oil, reusability of the sorbent and sorption from the water surface were also determined. Maximum oil sorption capacity was determined as 9.67, 12.92 and 12.84 g/g for diesel oil, 0W30 and 10W30 motor . . .oils respectively for the static test and 8.27, 10.45 and 11.69 g/g for the dynamic test. An efficient and low-cost sorbent was produced from paper industry rejects that can be used on land and on water. © 2017 Elsevier Lt Daha fazlası Daha az

Tecer, Lokman Hakan | Yılmaz, Ali | Yıldırım, Yılmaz

Bildiri | 2004 | AIR POLLUTION MODELING AND ITS APPLICATION XVI16 , pp.637 - 638

In this study air pollution level in the city center of Sivas for a 10 years' period was analyzed. Winter season' and annual averages of sulfur dioxide and particulate matter measurements have been carried out in central area of Sivas by City Health Management. Specifically the winter seasons' concentrations are presented and their causes and their change with respect to meteorological parameters are discussed. The statistical relations between pollutants and meteorological parameters have been found to be significant.

Çoruh, Nursen | Özdoğan, Nizamettin

Makale | 2017 | Turkish Journal of Biology41 ( 1 ) , pp.195 - 212

Rosa heckeliana, as one of the wild-growing species of the family Rosacea, has a wide use in the folk medicine; however, scientifically there is very little known about it. Our objective was to examine the antioxidative and antiproliferative properties of Rosa heckeliana root extract and its phenolics. The phenolic constituents, namely catechin, caffeic acid, and ellagic acid, were obtained by the methods of extraction, fractionation, and purification through column chromatography. The DPPH and ABTS radical scavenging assays and total flavonoid content analysis were employed as the current antioxidant methods over the crude extract . . .and fractionated parts. Among the extracts/fractions, the ethyl acetate fraction exhibited the highest amount of flavonoid content (4.58 ± 0.018 µg CE/ mg of extract). The ethyl acetate fraction also displayed high antioxidative properties for DPPH (EC50 value: 2.78 ± 0.01 µg/mL) and ABTS scavenging capacities (586 ± 6.64 µM trolox as TEAC value). Additionally, the antiproliferative properties of the crude extract and the ethyl acetate fraction and its isolated constituents were evaluated for two breast cancer cell lines (MCF-7 and MDA-MB-231) using the XTT method. Acetate fraction over the cells of MCF-7 and MDA-MB-231 resulted in ED50 values of 61.18 ± 0.99 µg/mL and 62.54 ± 2.01 µg/mL, respectively. The isolated phenolic constituents were twice as effective as the ethyl acetate fraction on both MCF-7 and MDA-MB-231 cells. Rosa heckeliana, as one of the wild-growing species of the family Rosacea, has a wide use in the folk medicine; however, scientifically there is very little known about it. Our objective was to examine the antioxidative and antiproliferative properties of Rosa heckeliana root extract and its phenolics. The phenolic constituents, namely catechin, caffeic acid, and ellagic acid, were obtained by the methods of extraction, fractionation, and purification through column chromatography. The DPPH and ABTS radical scavenging assays and total flavonoid content analysis were employed as the current antioxidant methods over the crude extract and fractionated parts. Among the extracts/fractions, the ethyl acetate fraction exhibited the highest amount of flavonoid content (4.58 ± 0.018 µg CE/ mg of extract). The ethyl acetate fraction also displayed high antioxidative properties for DPPH (EC50 value: 2.78 ± 0.01 µg/mL) and ABTS scavenging capacities (586 ± 6.64 µM trolox as TEAC value). Additionally, the antiproliferative properties of the crude extract and the ethyl acetate fraction and its isolated constituents were evaluated for two breast cancer cell lines (MCF-7 and MDA-MB-231) using the XTT method. Acetate fraction over the cells of MCF-7 and MDA-MB-231 resulted in ED50 values of 61.18 ± 0.99 µg/mL and 62.54 ± 2.01 µg/mL, respectively. The isolated phenolic constituents were twice as effective as the ethyl acetate fraction on both MCF-7 and MDA-MB-231 cells Daha fazlası Daha az

Yıldırım, Yılmaz | Demircioğlu, Nuhi | Kobya, Mehmet | Bayramoğlu, Mahmut

Makale | 2002 | Environmental Pollution118 ( 3 ) , pp.411 - 417

A non-linear simple air-quality model was developed by applying the continuity equation for the air control volume over Erzurum city center and tested using daily average values of SO2 and meteorological data obtained during the winter seasons in Erzurum, Turkey from 1994 to 1998. Model parameters are estimated by non-linear regression analysis. Agreement between model predictions and measured data was found very satisfactory with standard deviations less than 20 µg/m3. © 2002 Elsevier Science Ltd. All rights reserved.

Altın, Süreyya | Altın, Ahmet

Makale | 2019 | Journal of Electrochemical Science and Technology10 ( 1 ) , pp.14 - 21

Supported liquid membrane process usually is used for recovering or enrichment of valuable metals in the industrial wastewater. But, even if the metals in the wastewater was separated with high chemical selectivity, it cannot be enough concentrated since separation performance of supported liquid membrane (SLM) process is limited by concentration gradient between feed solution and stripping solution. If metal concentration in the stripping solution to be enough low, transport of metal through membrane can be accomplishment constantly. Therefore, Electrodialysis (ED) has been placed after SLM process and the stripping solution of SLM . . . was used as the feed solution for the ED process. Transport of ions in the solutions is successfully performed by ED process. Thus, the metal concentration in the stripping solution does not rise as to stop ion transport. Besides, valuable metals easily are concentrated by ED process for re-use. In this study, effects of operation parameters like initial Cd(II) concentration, HCl concentration in the feed solution of SLM and applied voltage are investigated on separation efficiency, flux and permeability of the both processes. As the feed solution concentration increased, all performance values has increased. When initial concentration of 100 mg/L is used, separation performances (SP) are 55% and 70%, for SLM and consecutive process, respectively. The best HCl concentration in the feed solution of SLM has determined as 2 M, in this conditions SP are 64% and 72%, for SLM and consecutive process, respectively. With increased of applied voltage on ED process, SP of the consecutive process has been raised from 72% to 83%. According to the obtained experimental data, consecutive process has better separation performance than SLM. When the separation performances of both processes were compared for the same operating conditions, it was determined higher the separation efficiency, permeability and flux values of the consecutive process, 8%, 9% and %10.6, respectively. Consequently, the use of the consecutive process increases the performance efficiency of both processes. The consecutive process studied has quite a good chemical separation efficiency, and enrichment capability. Moreover, this process requires few water and energy. © 2019, Korean Electrochemical Society. All rights reserved Daha fazlası Daha az