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    Adaptive neuro fuzzy inference system for estimating particle diameter of soils in micro structure for varying quantities of sodium hexametaphosphate
    (Academic Journals, 2010) Bektaş, Salih; Özgan, Ercan
    In the present study, 0, 10, 20, 30, 40, 50 and 60 g. Sodium hexametaphosphate (NaPO3) suspensions were prepared for hydrometer tests. After the completion of the tests, the particle diameters of the soil were calculated for each hydrometer reading at time intervals of ( 0, 1, 2, 5, 10, 15, 30, 60, 120 and 260 min). A model was developed using an adaptive neuro-fuzzy inference system (ANFIS) to predict the particle diameter of soil for different cases without the need for a test. The quantities of the NaPO3 and the hydrometer reading times were used as inputs in the model. Test results and predicted outcomes were compared and high correlations were obtained.
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    Adaptive neuro-fuzzy inference approach for prediction the stiffness modulus on asphalt concrete
    (Elsevier Sci Ltd, 2012) Özgan, Ercan; Korkmaz, İbrahim; Emiroğlu, Mehmet
    In this study, stiffness modulus parameters of asphalt concrete were determined experimentally for different temperature and exposure times. The stiffness modules were calculated according to Nijboer stiffness module. Basic physical properties and the quantity of bitumen of asphalt core samples were designated for determining the stiffness modules. The samples were exposed to 17 degrees C (reference temperature), 30, 40 and 50 degrees C temperatures for 1.5, 3, 4.5 and 6 h respectively and then Marhall Stability tests were done for each samples. By using the test results a prediction model with Sugeno type based on the adaptive neuron-fuzzy inference system (ANFIS) was alternatively developed to predict the stiffness modules of asphalt core samples. As a result, it was seen that the developed prediction model could be used as a prediction model for unperformed situations which are not suitable for experiments. (C) 2011 Elsevier Ltd. All rights reserved.
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    ANALYSIS OF THE RELATIONSHIP BETWEEN RESULTS OF ACCIDENTS WITH HIGHWAYS' VEHICLE TYPE AND KINDS OF THE ACCIDENTS
    (Gazi Univ, Fac Engineering Architecture, 2008) Özgan, Ercan
    In this study, effects of vehicle types and kind of the accidents, to the results of the traffic accidents on highways, were analyzed. For this purpose, the reports of a total 783 traffic accidents that took place on highway D100/11 between 2000 and 2004. For each one accident vehicle types, kind of accident and the number of dead and injured were determined. The collected data was formed in a table and using SPSS program, multi lineer regression, correlation and varience analysis were done. Depending on the vehicle types, prediction modals were formed for prediction of the number of accidents, the number of dead and the number of injured. It was discovered that in terms of correlation between the vehicle types and the deadly accidents, with 0,49 correlation value pickup trucks are at the first place, with 0,43 correlation value lorries are at the second place and with 0,21 correlation value buses are at the last place. In terms of correlation between the vehicle types and accidents with injured people, while with 0,90 and 0,82 correlation cars and pickup trucks take the first and the second places associatively, with 0,23 bicycles take the last place. In terms of causing accidents, while with 0,97 and 0,77 correlation cars and pickups take the first and the second places associatively and again with 0,23 bicycles take the last place. In terms of correlation between how accidents happen and the vehicle types, it was discovered that the correlation between cars and the collision type of accidents is 0,867, and the correlation between the lorries and turn over kind of accidents is 0,59. It has also been discovered in terms of accidents causing dead or injured, with 0,915 and 0,743 correlation, collision type of accident and collision with stable objects take the first and second places, and with 0,244 correlation, collision with a pedestrian takes the last place.
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    Artificial neural network based modelling of the Marshall Stability of asphalt concrete
    (Pergamon-Elsevier Science Ltd, 2011) Özgan, Ercan
    In this study, the Marshall Stability (MS) of asphalt concrete under varying temperature and exposure times was modeled by using artificial neural network. In order to investigate the MS based on physical properties, exposure time and environment temperature, exposure times of 1.5, 3, 4.5 and 6 h and temperatures of 30 degrees C, 40 degrees C and 50 degrees C were selected. The results showed that at the environment temperature of 17 degrees C the stability of the asphalt core samples decreased by 40.16% at 30 degrees C after 1.5 h and 62.39% after 6 h. At 40 degrees C, the decrease was 74.31% after 1.5 and 78.10% after 6 h. At 50 degrees C the stability of the asphalt decreased by 83.22% after 1.5 h, and 88.66% after 6 h. Experiment results and ANN model exhibited good correlation for this reason the ANN method could be used to model the MS. (C) 2010 Elsevier Ltd. All rights reserved.
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    Asfalt çimentolarında duktulitenin bulanık mantıkla tahmini
    (2009) Özgan, Ercan
    Bu çalışmada, asfalt çimentosunun farklı sıcaklık ve bekleme sürelerine bağlı olarak duktulitesindeki değişim incelenmiştir. Bu amaçla AC 40 sınıfı asfalt çimentosu kullanılarak 15, 20 ve 25 oC sıcaklıklarda sırasıyla 1, 1.5 ve 2 saat bekletilerek 72 adet duktulite deneyi yapılmış ve deney sonuçları referans duktulite değerleri ile karşılaştırılarak aralarındaki ilişkiler belirlenmeye çalışılmıştır. Referans sıcaklığın ve bekleme sürelerinin sağlanamadığı şartlarda da duktulite deneylerinin yapılabilirliği gösterilmiş, deneylerle belirlenmemiş olan duktulite değerlerinin sıcaklık ve bekleme sürelerine bağlı olarak tahmin edilebilmesi için de Bulanık Mantık metoduyla tahmin modeli oluşturulmuş ve oluşturulan modelin bu amaçla kullanılabileceği gösterilmiştir.
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    BETONARME BİR OKUL BİNASININ 2007 DEPREM YÖNETMELİĞİNE GÖRE PERFORMANS ANALİZİ
    (Düzce Üniversitesi, 2017) Kap, Tuncay; Özgan, Ercan; Uzunoğlu, Metin Mevlüt
    Ülkemizin büyük bir bölümü deprem bölgesidir. Deprem bölgelerindeyer alan yapıların projelerine uygun yapılıp yapılmadıkları yapım aşamasındakontrol edilse de, gerçek durum olası bir deprem sonucunda ortaya çıkmaktadır.Yaşanan depremler sonucunda Çevre ve Şehircilik Bakanlığı, Yapıların Tasarım veYapım Kuralları içeren yönetmelik ve standartlarda değişiklikler yaparakDepreme dayanıklı yapılar inşa edilmesini hedeflemektedir. Bu kapsamda Çevre veŞehircilik Bakanlığı en son 2007 Yılında “Deprem Bölgelerinde Yapılacak BinalarHakkında Esaslar” yönetmeliğini yayınlamıştır. Bu yönetmelik yayınlanmadan önceinşa edilen yapılar yeni yönetmelik şartlarını sağlamadığı için yetersizkalabilmektedir. Bu nedenle yürürlükte olan 2007 yönetmeliğine göre mevcut yapılarınperformansları incelenerek, olası bir deprem etkisinde gösterecekleri davranışönceden tahmin edilebilir ve bu duruma göre gerekli tedbirleralınabilmektedir.  Bu çalışma, AkçakocaCumhuriyet İlköğretim Okulu binasının 2007 yönetmeliğindeki şartlara uygunlukdüzeyini belirlemek amacıyla örnek bir uygulama olarak yapılmıştır. Çalışmada,Cumhuriyet İlköğretim Okulu binasında sistem elemanlarının kapasitelerininbelirlenmesi, deprem dayanımlarının değerlendirilmesinde kullanılacak elemandetayları ve boyutları, taşıyıcı sistem geometrisi ve malzeme özellikleridetaylı olarak incelenmiştir. Binanın temeli hakkında bilgi edinebilmek için binanıniçinde ve dışında temel muayene çukurları açılmıştır. Yapının betonarmeelamanların da donatı tespiti, pay durumu ve donatı çaplarının belirlenebilmesiamacıyla sıyırma işlemleri yapılmış ve beton karot numuneleri alınmıştır. Binanınmimari projeleri çizilmiş ve elde edilen verilerle binanın 2007 yönetmeliğineuygunluğu STA4-V13.1 “Structural Analysis for Computer Aided Design” programıile analiz edilmiş ve değerlendirmelerde bulunulmuştur.
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    Betonarme Bir Okul Binasının 2018 Deprem Yönetmeliğine Göre İncelenmesi
    (2019) Kap, Tuncay; Özgan, Ercan; Uzunoğlu, Metin Mevlüt
    Bu çalışmada ülkemiz toprak alanlarının büyük bir çoğunluğu deprem bölgesinde olması nedeniyle Çevre veŞehircilik Bakanlığı, deprem etkisi altında yeni binaların tasarımında ve mevcut binaların değerlendirilmesindedeğişiklikler yaparak depreme dayanıklı yapıların inşa edilmesini hedeflemektedir. Bu amaçla 2018 Depremyönetmeliği hazırlanmıştır. Yönetmelikte, mevcut binaların zemin özelliklerinin nasıl belirleneceği belirtilmiştir.Bu kapsamda, zemin grupları taşıma gücü açısından en yüksekten en düşüğe doğru A, B, C, D, E, F olarak 6farklı grupta tanımlanmıştır. Bu çalışmada, 1999 Marmara ve Düzce depremlerinden etkilenmiş ve taşıma gücüyüksek bir zeminde inşa edilmiş bir okul binasının deprem performans analizi yapılmıştır. Binadaki taşıyıcıelemanların kapasiteleri belirlenmiş ve deprem dayanımları değerlendirilmiştir. Binanın içinde ve dışında temelmuayene çukurları açılarak temel şekli ve boyutları belirlenmiştir. Sahada zeminin taşıma gücü ve bazıözelliklerin belirlenmesi amacıyla 3 adet sondaj kuyusu açılmıştır. Binanın taşıyıcı elemanları üzerinde donatıçap ve paspayları ölçülerek kolon ve kirişlerden yönetmelikte belirtilen sayıda karot numuneleri alınaraklaboratuar ortamında beton basınç dayanımları bulunmuştur. Proje verilerinden elde edilen bilgiler 2018yönetmeliğine göre “STA4-V14.1” paket programı ile analiz edilmiştir.
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    Determining the stability of asphalt concrete at varying temperatures and exposure times using destructive and non-destructive methods
    (Asian Network for Scientific Information, 2007) Özgan, Ercan
    This study examined the effect of varying temperatures and varying exposure times on the stability of asphalt conrete using destructive and non-destructive methods. The study also looked at the relationship between destructive and non-dcstructive methods. In order to investigate the stability according to exposure time and environment temperature, exposure times of 1.5, 3, 4.5 and 6 h and temperatures of 30, 40 and 50°C were selected. The results showed that at the environment temperature of 17°C the stability of the asphalt core samples decreased by 40.16% at 30°C after 1.5 h and 62.39% after 6 h. At 40°C the decrease was 74.31% after 1.5 and 78.10% after 6 h. At 50°C the stability of the asphalt decreased by 83.22% after 1.5 h and 88.66% after 6 h. The results also pointed to a moderate negative relationship (R = -0.533) between second ultrasound and stability indicating that non-destructive ultrasound method can be used to predict stability. © 2007 Asian Network for Scientific Information.
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    EFFECTS OF FREEZING AND THAWING CYCLES ON THE ENGINEERING PROPERTIES OF SOILS
    (Springer, 2015) Özgan, Ercan; Serin, Sercan; Ertürk, S.; Vural, İsa
    In this study, particular engineering characteristics of soil exposed to freezing and thawing cycles were investigated. Low plasticity clay (CL) soil samples (classified according to the USCS soil classification system) were sampled in situ, and some basic properties of these soil samples were investigated by performing sieve analyses, hydrometer tests, specific gravity tests, and liquid, plastic, and shrinkage limits tests. The same tests were also conducted after freezing and thawing cycles. Additionally, scanning electron microscope (SEM) tests to determine the microstructures of the soil samples and energy dispersive X-ray-EDX tests to determine the chemical compositions of the samples were performed. Finally, triaxial compression tests were conducted before and after the freezing and thawing cycles to determine the strength parameters of the soil samples. The experimental results show that the physical and mechanical properties of the soil changed significantly after the freezing and thawing cycles.
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    Effects of Freezing and Thawing on the Consolidation Settlement of Soils
    (Springer, 2015) Özgan, Ercan; Serin, Sercan; Ertürk, S.; Vural, İsa
    The effects of freezing and thawing on consolidation parameters and other properties of soil were investigated experimentally. Samples of soils were collected in-situ and characterized in the laboratory. Index properties of soil samples were determined by conducting sieve analyses, hydrometer tests, specific gravity tests, and liquid limit, plastic limit, and shrinkage limit tests before and after 30 freezing-thawing cycles. Microstructure and elemental composition of the soil samples were determined by scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis, respectively. To determine the effects of freezing thawing onto the consolidation parameters of soil, consolidation tests were conducted on the samples before and after the freezing-thawing cycles. After 30 freezing-thawing cycles, consolidation settlements increased by about 23%.
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    Eğilme momentine maruz çerçeve konstrüksiyonlu "L" tipi köşe birleştirmelerin performanslarının incelenmesi
    (2008) Özgan, Ercan; Kap, Tuncay
    Bu çalışmada, Sarıçam (Pinus Sylvestris Lipsky), Doğu Karadeniz Köknarı (Abies Nordmanniana), Anadolu Kestanesi (Castanea Sativa Mill.) ve Toros Sediri (Cedrus Libani A. Rich.) türlerinden imal edilen, Düz Zıvanalı, Düz Zıvanalı-Kavelalı, Gizli Zıvanalı, Gizli Zıvanalı-Kavelalı birleştirme teknikleriyle oluşturulan köşe birleştirmelerin dış eğilme momenti etkisi altındaki performansları incelenmiştir. Bu amaçla toplam 160 adet çerçeve konstrüksiyonlu köşe birleştirme örneği hazırlanmıştır. Birleştirmelerde eğilme etkisindeki en büyük ortalama bileşik basınç gerilmesinin Düz Zıvana Kavelalı olarak birleştirilen Çam ağacında, buna karşılık eğilme etkisindeki en düşük ortalama basınç gerilmesinin ise Gizli Zıvana Kavelalı olarak birleştirilen Köknar ağacında meydana geldiği belirlenmiştir. Kavelanın, Çam ağacında bileşik eğilme etkisindeki basınç gerilmesini Düz Zıvanalı birleştirmede %3 oranına kadar, Gizli Zıvanalı birleştirmede ise %9 oranına kadar arttırdığı görülmüştür. Köknar ağacında, basınç gerilmesini Düz Zıvanalı birleştirmede %20,3 oranına kadar, Gizli Zıvanalı birleştirmede ise %8,9 oranına kadar azalttığı görülmüştür. Kestane ağacında, basınç gerilmesini Düz Zıvanalı birleştirmede % 6,6 oranına kadar artırdığı ancak Gizli zıvanalıda %10,4 oranına kadar azalttığı görülmüştür. Sedir ağacında, basınç gerilmesini, Düz zıvanalıda % 2,4 oranına kadar azalttığı ancak Gizli zıvanalıda ise % 19,5’e kadar arttırdığı görülmüştür.
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    An experimental study on the effects of different injection materials on consolidation settlement
    (2011) Bektaş, Salih; Özgan, Ercan
    Injection applications with injection material types such as bentonite, rheocem, rheobuild 1000, bentonite+rheocem was made and the effect of the injection on soil consolidation settlement was experimentally studied. A sample of natural soil, whose geotechnical characteristics are known to be weak, was analyzed to determine its basic physical properties and the sample was injected with mixtures prepared with natural bentonite, rheocem650 and rheobuild1000. Settlement values of these samples under different loads were experimentally determined and settlement values of the natural sample were taken as reference values. Settlement values for different loads obtained from the experiments were compared with each other. When reference values for all loads on natural samples are taken as (100%), it was seen that the average settlement value of bentonite injected samples was 47.19% higher compared to the settlement values of the natural sample, the average settlement value of rheocem injected samples was 18.51% less compared to the settlement values of the natural sample and the average settlement value of bentonite+rheocem injected samples was 36.12% less compared to the settlement values of the natural sample. © 2011 Academic Journals.
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    Fuzzy logic and statistical-based modelling of the Marshall Stability of asphalt concrete under varying temperatures and exposure times
    (Elsevier Sci Ltd, 2009) Özgan, Ercan
    In this study, the Marshall Stability(MS) of asphalt concrete under varying temperature and exposure times was modelled by using fuzzy logic and statistical method. This is an experimental study conducted using statistics and fuzzy logic methods. In order to investigate the Marshall Stability of asphalt concrete based on exposure time and environment temperature, exposure times of 1.5, 3.4.5 and 6 h and temperatures of 30,40 and 50 degrees C were selected. The MS of the asphalt concrete at 17 degrees C(in laboratory environment temperature) was used as reference. The results showed that the MS of the asphalt core samples decreased 40.16% at 30 degrees C after 1.5 h and 62.39% after 6 h. At 40 degrees C the decrease was 74.31% after 1.5 h, and 78.10% after 6 h. At 50 degrees C the stability of the asphalt decreased 83.22% after 1.5 h, 88.66% after 6 h. The relationships between experimental results, fuzzy logic model and statistical results exhibited good correlation. The correlation coefficient was R = 0.99 for fuzzy logic model and R(2) = 0.9 for statistical method. Based on the results Of the study, it could be said that both the fuzzy logic method and statistical methods could be used for modelling of the stability of asphalt concrete under varying temperature and exposure time. (C) 2008 Elsevier Ltd. All rights reserved.
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    Genetic Algorithm Application for Hydrometer Tests
    (Asian Journal Of Chemistry, 2009) Özgan, Ercan; Öztürk, Ali
    In this study, the results of the hydrometer tests were analyzed with statistical method and optimized by using genetic algorithms. For hydrometer tests; 0, 10, 20, 30, 40, 50 and 60 g sodium-hexametaphosphate was respectively added into the prepared suspension. The specific gravity, pH and the conductivity were measured for each solution. As pointed out in the Turkish Standard (TS 1900), the soil' grain diameter in the suspension prepared with 40 g sodium hexametaphosphate was taken into consideration as reference. As a result. it was determined that the soil' average grain diameter in suspension added 0 g sodium hexametaphosphate was bigger 4.515 times than the reference grain diameter. When respectively added 10 g sodium hexametaphosphate in the suspension, the soil average grain diameter bigger was 3.907 times than the reference grain diameter, when 20 g was added. It was 3.463 times bigger and in adding it was 30 g 2.119 times bigger. Besides, the hydrometer reading could only be done at 260 min when 50 g sodium hexametaphosphate was added in to the suspension. Moreover, the hydrometer couldn't be read in the suspension prepared with 60 g sodium hexametaphosphate. The obtained data were analyzed statistically by using SPSS programme and the experimental results were optimized by using genetic algorithms.
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    INVESTIGATING THE PERFORMANCE OF THE "L" TYPE FRAME CONSTRUCTION CORNER JUNCTIONS EXPOSED TO THE INCLINING MOMENT
    (Gazi Univ, Fac Engineering Architecture, 2008) Özgan, Ercan; Kap, Tuncay
    In this study, the performances of the corner joints prepared using by plain mortise, hidden mortise and constructional joint techniques and made from yellow pine (Pinus Sylvestris Lipsky), fire tire (Abies Nordmanniana), Chenust (Castanea Sativa Mill.) and cedar wood (Cedrus Libani A. Rich.) were investigated under the inclining moment effects. For this purpose, totally 160 unit frame construction corner junction models were prepared. It was determined after the tests that, when the yellow pine materials were used (Pinus Sylvestris Lipsky), the highest average composed inclining pressure resistance occurred with plain mortise and the lowest average pressure resistance occurred with hidden mortise in fire tire (Abies Nordmanniana) on the junctions. When dowel was used in the corner joints it was observed that the pressure resistance, under the inclining moment, increased about 3% at plain mortise and increased 9% at hidden mortis in yellow pine. The pressure resistance, under the inclining moment, decreased about 20,3% at plain mortise and decreased about 8,9% at hidden mortis in fire tree. chestnut tree. The pressure resistance, under the inclining moment, increased about 6,6% at plain mortise and decreased about 10,4% at hidden mortis in the chestnut tree. The pressure resistance, under the inclining moment, decreased about 2,4% at plain mortise and increased about 19,5% at hidden mortis in the cedar wood.
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    Investigation and modelling the effects of water proofing and water repellent admixtures dosage on the permeability and compressive strengths of concrete
    (Elsevier Sci Ltd, 2016) Apay, Ahmet Celal; Özgan, Ercan; Turgay, Tahsin; Akyol, Kevser
    In this study, structural waterproofing products, structural water insulation applications and effects of waterproofing admixtures on the concrete were experimentally investigated. Different dosages in the concrete mixture (0%, 0.5%, 1.0%, 1.5% and 2.0%) were used to determine the effect of the chemical additive on the permeability of the concrete and the compressive strength the chemical additives. Maximum particle diameter of the aggregate used in the concrete mixture was selected 32 mm accordance to the Turkish Standard 802 "Design of concrete mixes" (TS 802) [1]. The selected aggregate granulometry of concrete mixture is located in B32 section of this granulometry curve and by using PC 42.5 cement, 320 kg/m(3) dosage concretes were produced in laboratory by adding four different kinds of aggregates. The compressive strength and permeability of the hardened concrete samples were measured after 14 days. The measured results showed that while maximum compressive strength were measured as 36.1 N/mm(2) on the concrete samples prepared with 2% chemical additive the minimum water absorption were measured as 4% on the same samples. However, while minimum compressive strength were measured as 28.5 N/mm(2) on the concrete samples prepared with 0% (Reference samples) chemical additives the maximum water absorption were measured as 5.9% on the same samples. Statistical analyses were conducted to determine the relationship between experimental parameters on the compressive strength and water absorption of the hardened concrete samples. By using Adaptive Neural Fuzzy Inference System (ANFIS) prediction models were developed based on the experimental inputs to predict the compressive strength and water absorption of the hardened concrete samples. The results showed that both statistical and ANFIS methods' results have perfect match with experimental results. The prediction models can be used to predict the compressive strength and water absorption of concrete samples for known and unknown experimental inputs values. (C) 2016 Elsevier Ltd. All rights reserved.
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    The Investigation into the Effect of Hydrostatic Pressure on the Engineering Properties of Hardened Concrete
    (Taylor & Francis Ltd, 2018) Uzunoğlu, Metin M.; Özgan, Ercan; Kap, Tuncay
    The aim of this study is to investigate the effect of hydrostatic pressure on the engineering properties of hardened concrete. To this end, a concrete column with dimensions of 100 cm width, 25 cm depth and 250 cm height was produced using C20 class concrete. While pouring the concrete, 15 cm reference cube samples were taken from the fresh concrete. After 28 days, 8 from the cube samples and 128 from different hydrostatic heights, in total 136 pieces of core samples with & Oslash;100 mm diameter were taken and their compressive strength was determined. The average compressive strength of the reference core samples was 36.95 N/mm(2) and the compressive strength of other samples changed between 37.3 N/mm(2) and 43.0 N/mm(2) according to the hydrostatic pressure. It was concluded that compressive strength changed between 0.95% and 16.37% according to the reference sample. Statistical analysis was conducted based on the experimental results. The compressive strength of the core samples related to its hydrostatic height and physical properties were predicted with a high reliability. A model equation was formed to convert the compressive strength of the core samples into reference compressive strength according to hydrostatic height and the convertibility coefficients were ascertained.
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    Investigation of certain engineering characteristics of asphalt concrete exposed to freeze-thaw cycles
    (Elsevier Science Bv, 2013) Özgan, Ercan; Serin, Sercan
    In this study the effects of freeze and thaw cycles on asphalt concrete materials are investigated for binder and wearing surface coats, separately, and for different freeze and thaw cycles. Asphalt concrete (AC) was produced in a laboratory environment, and tests were conducted. Different specimens were prepared with different binders and wearing course based on the calculated pre-optimum bitumen amount, and the optimum bitumen amount was experimentally determined for each layer. According to the value determined for amount of bitumen, 15 AC specimens were prepared for each layer, for a total of 30 specimens. The prepared specimens were exposed to freeze and thaw cycles for 6, 12, 18, and 24 days. Before and after each cycle, the voids ratios filled with asphalt (V-f), void ratio (V-h), and the voids ratios inside mineral aggregate (V-MA) parameters; ultrasonic velocity; and Marshall Stability (MS) values were experimentally determined for each specimen. The results obtained for reference specimens were compared against the values experimentally obtained from the specimens that were exposed to the freeze-thaw effect for 6, 12, 18, and 24 days. (C) 2012 Elsevier B.V. All rights reserved.
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    Investigation of corrosion behavior of 6060 and 6082 aluminum alloys under simulated acid rain conditions
    (Wiley-V C H Verlag Gmbh, 2015) Gerengi, Hüsnü; Slepski, Pawel; Özgan, Ercan; Kurtay, Mine
    Instantaneous impedance changes of 6060 and 6082 type aluminum alloys in pure water, and simulated acid rain poured into the pure water was investigated by dynamic electrochemical impedance spectroscopy (DEIS). In this way, the influence of aluminum content on the corrosion behavior of 6060 and 6082 type aluminum alloys immersed in simulated acid rain was determined. The corrosion rate of the alloy decreased with increasing Al content, which may be related to the distribution of the Al-rich phase. The surface morphology of studied alloys was also examined with scanning electron microscopy.
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    INVESTIGATION OF THE EFFECT OF THE QUANTITY OF SODIUM HEXAMETAPHOSPATH TO THE HYDROMETER TEST RESULTS WITH EXPERIMENTAL AND STATISTICAL METHODS
    (Gazi Univ, Fac Engineering Architecture, 2009) Özgan, Ercan
    In this study, the effect of quantity of sodium hexametaphosphate (NaPO(3)) to the soil grain' diameters were investigated as experimental and statistically. Hydrometer testing was conducted. 0, 10, 20, 30, 40, 50 and 60 gr NaPO(3) was respectively added into the prepared suspension. The specific gravity, pH and the conductivity were measured for each suspension. As pointed out in the TS 1900-1-2006 (Turkish Standard), the soil' grain diameter in the solution prepared with 40 gr NaPO(3) was used as reference. As a result, it was determined that the soil grain diameter in suspension added "0" gr NaPO(3) greater 4.51 time than the reference grain diameter. When respectively added 10 gr into the suspension, the soil' grain diameter greater 3.90 time than reference grain diameter, added 20 gr 3.46 time, and added 30 gr 2.12 time. Besides, the hydrometer reading could be done only 260(th) minute when added 50 gr in to the suspension. Moreover, the hydrometer couldn't be read in the solution prepared with 60 gr NaPO(3). The obtained data were analysed statistically by using SPSS programme and determined the correlation coefficients for the hydrometer test parameters (passing time, original hydrometer reading, temperature, pH, conductivity, The correction coefficient value for solving matter and temperature, corrected hydrometer reading, effective deep, value of the K, particle diameter and quantity of the NaPO3). Also, regression analysis was conducted (R=0.87) to predict the corrected hydrometer test reading based on the original hydrometer reading and the quantity of the NaPO(3).