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.

Sasa, Aybüke | Şentürk, Fatiha | Üstündağ, Yeşim | Erem, Fundagül

Makale | 2020 | Uluslararası Mühendislik Tasarım ve Teknoloji Dergisi2 ( 2 ) , pp.97 - 110

Artan nüfusla birlikte karşılaşılabilecek gıda yetersizliği ve dengesiz beslenme gibi sorunlar insanoğlunu alternatif kaynaklar bulmaya itmiştir. Bu bağlamda, algler sürdürülebilir gıda arzını sağlayabilmenin yanı sıra, yüksek besin içerikleri ve sağlık açısından faydalı yönleriyle dikkat çekmekte ve bu özellikleriyle aynı zamanda fonksiyonel gıda olmaya aday ürünler olarak değerlendirilmektedir. Alglerin ürettiği fonksiyonel bileşenlerin ilave edildiği gıdaların günlük olarak tüketilmesi sağlığı iyileştirip kronik hastalık riskini azaltabilmektedir. Asya ülkelerinde yüzyıllardır gıda olarak değerlendirilen algler artık dünyanın hem . . .en hemen her bölgesinde gerek doğrudan gıda gerekse gıda katkı maddesi veya gıda takviyesi olarak kullanılmaya başlanmıştır. Algler gıda endüstrisi dışında tıp, eczacılık, tarım, hayvan beslenmesi, atıkların arıtılması, kozmetik, biyodizel üretimi gibi pek çok alanda yararlanılan önemli kaynaklar arasında yer almaktadır. Bu derlemede alglerin genel özellikleri, önemli bileşim öğeleri, doğrudan gıda olarak ya da gıdalarda kullanımlarına yönelik ve sağlığa faydalarıyla ilgili bilgiler özetlenmiştir Daha fazlası Daha az

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

Özer, Mahmut

Bildiri | 2003 | Mathematical and Computational Applications8 ( 1-3 ) , pp.71 - 78

In this study, phase-plane analysis is carried out for a simplified model of Purkinje cell dendrite in terms of voltage-gated ionic channels involved. State variables, nullclines and equilibrium points of the model are determined, and effects of ionic channel conductance and injected current on the shape of nullclines and the equilibrium points are investigated. In this study, phase-plane analysis is carried out for a simplified model of Purkinje cell dendrite in terms of voltage-gated ionic channels involved. State variables, nullclines and equilibrium points of the model are determined, and effects of ionic channel conductance and . . . injected current on the shape of nullclines and the equilibrium points are investigated Daha fazlası Daha az

Görmüş, K. Sedar | Mekik, Çetin | Kutoğlu, Hakan Şenol

Diğer | 2006 | HKM Jeodezi Jeoinformasyon Arazi Yönetimi Dergisi0 ( 95 ) , pp.25 - 35

Bu çalışmada, Gerçek Zamanlı Kinematik (GZK) GPS ile köprü salınımlarının modellenmesinde farklı bir yöntem olarak daha çok Elektrik-Elektronik mühendisliği disiplininde kullanılan ve bir zaman serileri analiz yöntemi olan Hızlı Fourier Dönüşüm (FFT) tekniği kullanılmıştır. Bu amaçla Zonguldak kent merkezindeki 1956 yılında tamamı perçinli çelik konstrüksiyon olarak inşa edilen Fevkani Köprüsünün, günün farklı zamanlarındaki trafik yoğunluğuna göre salınım ve titreşimleri GZK GPS ile ölçülmüştür. Bunun için referans alıcısı kentin yüksek tepelerinden birinin üzerine yerleştirilmiş ve iki gezici alıcı da köprünün belirlenen iki nokta . . .sında sabit merkezlendirme düzeneği üzerine konulmuştur. Trafiğin ve özellikle ağır tonajlı araçların en yoğun ve en seyrek geçtiği zamanlarda 1 saniye ölçü aralığı (interval) ile ölçmeler gerçekleştirilmiştir. Today GPS technology has found various uses in many fields as well as in geodetic applications. One of the most crucial factors in expanding the use of GPS is by means of the real time kinematic (RTK) GPS method which produces positions in a few seconds with a few centimeter accuracy, and consequently the productivity in projects. This study focuses on another use of RTK GPS or rather the employ ability of RTK GPS in another field. For this purpose, vibrations and resonance of the Fevkani Brigde -situated in the city centre of Zonguldak and built as a composite construction of riveted steel and asphalt in 1956-are observed by RTK GPS during the different parts of the day depending on the traffic density. The base (reference) receiver is placed on one of the highest hills in the city and two rover receivers on both rails of the bridge on the fixed centering mechanisms. The observations are carried out with one second interval during busy and less busy hours of the traffic, especially accounting for heavy load vehicle traffic. The changes in vibrations and resonance of the bridge computed by the analyses explained here are modeled using approaches such as Fast Fourier Transform and presented in this pape Daha fazlası Daha az

Erem, Fundagül | İnan, Mehmet | Karakaş Budak, Barçın | Certel, Muharrem

Makale | 2020 |

The aim of this study was to purify and characterize the peptidase of Bacillus amyloliquefaciens (Fukumoto) (strain FE-K1) isolated from ropey bread. Peptidases were purified from crude enzyme solution by affinity chromatography with an efficiency of 25 % and a purification coefficient of 1.53. The optimum pH of partially purified peptidase (PPPase) solution was determined as 7.5 and the peptidases retained approximately 90 % of their initial activity in the pH range 7.0-8.5 following incubation at 37°C for 2 h. The optimum temperature for the PPPase was 60°C. The approximate molecular weight of the PPPase was determined as 36 kDa. . . .Inactivation of the PPPase in the presence of O-FEN and EDTA showed them to be metallopeptidases and 5 mM of K+1 and 5 mM of Mn+2 ions increased the enzyme activity by 4 % and 6.15 %, respectively. The presence of Hg+2, Fe+3 and SDS (0.1-1.0 % w/v) caused inactivation whereas the enzyme retained most of its activity in the presence of 0.1-1.0 % (v/v) Triton X-100, Tween 20 and Tween 80 and 1-20 % (v/v) xylene, ethanol, acetone and acetonitrile. Characterization of the PPPase revealed the enzyme as a neutral serine metallopeptidase compatible with some organic solvents and surfactants Daha fazlası Daha az

Özer, Mahmut | Erdem, Rıza | Provaznik, Ivo

Makale | 2004 | NeuroReport15 ( 2 ) , pp.335 - 338

Voltage-gated ion channels are of great importance in the generation and propagation of electrical signals in the excitable cell membranes. How these channels respond to changes in the potential across the membrane has been a challenging problem, and different approaches have been proposed to address the mechanism of voltage sensing and gating in these channels. In this study, we attempt a new approach by considering a simple two-state gate system and applying the path probability method to construct a nonequilibrium statistical mechanical model of the system. The model which is based on the principles of statistical physics provide . . .s a firm physical basis for ion channel gating. © 2004 Lippincott Williams & Wilkins Daha fazlası Daha az

Kutoğlu, Hakan Şenol

Makale | 2007 | Harita Dergisi73 ( 18 (özel sayı) ) , pp.78 - 83

National heights systems throughout the world are referenced to the geoid whereas heighting by GPS directly results in ellipsoidal heights. These GPS-defined ellipsoidal heights have to be transformed into the national height systems. In practice, the surface polynomials are the most practical method to perform the transformation. Because of advances in computer science, surveyors have had an alternative method, the artificial neural networks, to the surface polynomials. In this study, these two methods are compared to each other using the data from Istanbul, Turkey. The investigations carried out show that the neural network method . . . provides comparable results in modeling general characteristics with the conventional polynomial, but better results in modeling local characteristics. National heights systems throughout the world are referenced to the geoid whereas heighting by GPS directly results in ellipsoidal heights. These GPS-defined ellipsoidal heights have to be transformed into the national height systems. In practice, the surface polynomials are the most practical method to perform the transformation. Because of advances in computer science, surveyors have had an alternative method, the artificial neural networks, to the surface polynomials. In this study, these two methods are compared to each other using the data from Istanbul, Turkey. The investigations carried out show that the neural network method provides comparable results in modeling general characteristics with the conventional polynomial, but better results in modeling local characteristics 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%.