Publications

To perform accurate seismic analyses of corroded reinforced concrete (RC) buildings, it is necessary to predict the bond-slip relationships to modify the moment-curvature relationships. In this study, empirical models were developed to predict the bond strength of corroded RC columns. Twenty-five RC columns were tested under combined cyclic lateral displacement excursions for three concrete strength levels—specifically, 9, 27, and 37 MPa (1305, 3915, and 5365 psi, respectively)—at two axial load ratios of 0.20 and 0.40 and at four corrosion levels. An accelerated corrosion method was applied to corrode the reinforcing bars embedded in the RC columns. The actual corrosion levels were determined by breaking the concrete and extracting all the longitudinal and transverse reinforcing bars from the RC columns. Three empirical models were developed. The first model was used to predict the development length of the corroded reinforcing bars. The second and third models were used to predict the bond strength and slip in the reinforcing bars as a function of the corrosion levels. The results indicated that previous models that predict the bond strength of corroded RC members were limited because of the theoretically considered development length of the noncorroded reinforcing bars.

Changes at different phases of a construction project are inevitable due to a multitude of reasons such as design changes, design errors, additions to scope, or unknown conditions that may arise due to resource limitations and the uniqueness of the project. For each change, contractors are entitled to an equitable adjustment to the base contract price and schedule. It is commonly accepted that change orders can have adverse effects on project performance, but these effects are difficult to quantify and manage, and they frequently lead to disputes. Most work in change order management focuses on labor productivity and does not pay as much attention to the quantification and management of the impact of change orders in regard to overall project performance in terms of time and cost. This paper describes a prototype expert system named QUICOPP that implements these ideas. The knowledge used in the system was acquired through a questionnaire survey administered to the contractors in North Cyprus construction industry. A list of factors that describe the adverse effects of change orders on project performance have been identified based on the survey, and this list of factors was used to develop a quantitative model of how different change orders affect the time and cost of a project. Our system provides a cost-effective means for handling change orders through all phases of a project such that construction operations can continue with the least amount of interruption that usually results from of disputes between different parties involved in a project.

The adsorption characteristics of methylene blue (MB) onto needles of Pinus sylvestris L., an unconventional bio-adsorbent, were investigated. Maximum removal of MB was found to occur at initial pH 5. Adsorption capacity increased from 84.46 to 99.73 mg/g with an increase in temperature from 20 to 45°C at 200 mg/L of initial MB concentration. Adsorption isotherms were modeled with the Langmuir, Freundlich, Tempkin and Harkis-Jura adsorption isotherms. The data fit well with the Langmuir isotherm. The maximum monolayer adsorption capacity of Pinus sylvestris L. needles was found to be 101 mg/g at 45°C. The adsorption kinetics of pseudo first-order, pseudo second-order, and Bangham were used for the kinetic studies. The pseudo second-order kinetic model provided the best fit to the experimental data compared with other kinetic adsorption models. Thermodynamic parameters such as ΔG°, ΔH°, and ΔS° were calculated. The adsorption of MB increased with increasing temperature and thermodynamic parameters, suggesting that the adsorption is spontaneous and endothermic in nature. FTIR spectrum result revealed the presence of adsorbing groups such as carboxyl, hydroxyl, and aromatic-CN stretching in the needles of Pinus sylvestris L. The experimental data obtained in the present study indicate that needles of Pinus sylvestris L. are suitable candidates for use as adsorbents in the removal of MB.

The main objective of this study was to assess and identify general construction faults and to investigate the effects of construction faults on the linear performance levels of reinforced concrete buildings. For doing this, observed two common construction faults (i.e., corrosion and honeycombing) were considered to be used in linear performance analyses. Finite element method was used to model the honeycombing at the column-beam joints. The effects of corrosion on the performance levels were ensured by reducing the cross-sectional area of reinforcement bars and reduced concrete compressive strength as a function of corrosion rate. Thus, two different construction faults on the levels of structural performance were discussed and compared. The results showed that the effects of honeycombing on performance levels of reinforced concrete building with linear performance analyses was more dramatic when it was compared with the results of damage building due to corrosion having a moderate to high corrosion threshold.

The sono, photo, and sonophotocatalytic degradations of Direct Blue 71 (DB71) in the presence heterogeneous TiO2 catalyst were studied at 20 kHz using ultrasonic (US) power of 95 W and aqueous temperature of 20°C for 20 min. The effects of various operational parameters such as the concentration of the dye, pH, and amounts of catalysts on the sonochemical degradation were also investigated. Sonochemical degradation of DB71 was strongly affected by initial substrate concentration, amounts of catalysts, and pH. Acidic pH was favored for the sonocatalytic degradation of DB71 using catalysts. The hybrid technique of sonocatalytic degradation was compared with the individual techniques of catalysis, sonolysis, and photocatalysis. The US degradation of dye was enhanced by catalyst addition. The structure and morphology of the catalyst were investigated using scanning electron microscopy and X-ray diffraction pattern.

The purpose of this study is to evaluate the waste tires that harm the environment as aggregate in concrete and to examine the effect on the mechanical properties of concrete. Three different classes (powder, crumb and chips) of waste rubber with seven different ratios (0%, 4%, 8%, 12%, 16%, 20% and 24%) and two different water to cement ratio (0.4 and 0.5) were used in concrete production. In this regard, this study conducted various experiments consisting of 28 and 90 days of the curing process to determine the properties of unit weight, compressive, flexural, and splitting tensile strength, along with ultrasonic pulse velocity (UPV) and dynamic modulus of elasticity. The waste rubber concrete with the highest compressive strength at the end of 90 days is the concrete that includes 4% waste rubber (0.4WR4) with 58.81 MPa. Concrete containing 8% waste rubber has the highest UPV of 5660 m/s after 90 days. The increase in the water/cement ratio from 0.4 to 0.5 and the waste rubber ratio cause deterioration in the mechanical properties of concrete. Although the use of waste rubbers does not bring an increase in strength, it is feasible to produce high strength concretes with 4% and 8% waste rubber substitution ratios. The water/cement ratio and curing time were highly effective on the mechanical properties of rubberized concrete.

Korozyona maruz kalmış betonarme yapıların sismik performanslarının tahmin edilmesi korozyona uğramamış yapılara göre daha zordur. Gerçekleştirilen bu deneysel çalışma ile birlikte korozyona maruz kalmış betonarme elemanları üzerine yapılacak olan çalışmalara ışık tutulması amaçlanmıştır. Beş adet tam ölçekli betonarme kolonu hızlandırılmış korozyon yöntemi kullanılarak farklı korozyon oranları için paslandırılmıştır. Paslandırılmış betonarme kolonları sabit eksenel yük altında monotonik yüklemeye tabi tutularak, akma ve nihai yükleri, süneklik oranları ve enerji yutma kapasiteleri deneysel olarak elde edilmiştir. Betonarme kolonlarındaki gerçek korozyon oranları yükleme deneylerinden sonra betonarme kolonlarının kırılarak ve gömülü olan tüm betonarme donatılarının çıkartılması ile elde edilmiştir. Yapılan deneysel çalışma sonucunda, monotonik yüklemenin tersinir-tekrarlanır yüklemeye göre zayıf yönleri göz önüne alınan deprem indeksleri açısından değerlendirilmiştir. Elde edilen deneysel sonuçlar doğrultusunda ileriki korozyon çalışmaları için önemli önerilerde bulunulmuştur. Gerçekleştirilen bu çalışma kapsamında, paslanmış betonarme kolonlarının monotonik yükleme etkisi altında süneklik oranları ve enerji yutma kapasiteleri artan korozyon oranına bağlı olarak azalmıştır. Monotonik yükleme etkisi altında pasın belirli oranlarına kadar sağlamış olduğu sargı etkisi ve buna bağlı olarak deprem indekslerindeki artışlar net bir şekilde görülememiştir. Tek doğrultuda göçme modu kabulü ile yapılacak olan sismik değerlendirmelerde kullanılmak üzere paslanmış betonarme kolonların süneklik ve enerji yutma kapasitelerinin tahmin edilebilmesi için iki ampirik model geliştirilmiştir.

Bu çalışmada 13 ve 14. yüzyıllarda Türkistan’da (Orta Asya) bilim ve edebiyat dili olan Harezm Türkçesine ait dil özelliklerini içinde barındıran ve 1313 tarihinde İslâm tarafından yazılmış Mu’înü’l Mürîd adlı eserde isimden isim yapma ekleri incelenmiştir. 407 dörtlükten oluşan ve dinî-tasavvufî öğretilerin yer aldığı eserde isimden isim yapma ekleri fişleme yöntemiyle belirlenmiş ve tasnif edilerek yorumlanmış, çalışma sonunda bazı sonuçlara ulaşılmıştır. Harezm Türkçesi, İslam dinine yönelen Türklerin yeni kavramları karşılamada ve dinî öğretileri insanlara en sade şekliyle anlatmada büyük bir görev üstlenmiş ve bunu Türkçenin ifade gücüyle ortaya koymuş bir dönemdir. Bu dönem, Oğuzların ve Kıpçakların tam manasıyla dil ve coğrafya olarak keskin bir ayrıma gitmediği bir dönemi kapsaması, eklerin ve kelimelerin belirlenerek günümüz kullanımlarına ve geçmiş şekillerine kaynaklık etmesi bakımından yine büyük bir önem taşımaktadır. Eserdeki tüm isimden isim yapma eklerinin kullanıldığı şekiller tespit edilerek çeşitli karşılaştırmalarda bulunmak ve bu eklerin benzerliklerini/farklılıklarını ortaya koyarak Türkçenin hâlâ tartışılmakta olan konularından yapım eklerine, eserde işlendiği şekliyle farklı bir bakış açısı sunabilmek; Harezm Türkçesinde kullanılan eklerin bugünkü şekillerini yapı ve işlev yönünden karşılaştırarak o dönem özellikleriyle çeşitli kıyaslamalarda bulunmak ve Türkçenin ekler vasıtasıyla ortaya koyduğu anlatım tarzını ve işler hâlini ortaya koymak hedeflenmiştir. 

The sonolytic and sonocatalytic degradation of Direct Blue 71 (DB71) in the presence Zero Valent Copper (ZVC) sonotocatalysts were studied at 20 kHz using ultrasonic power of 95W and aqueous temperature of 20 ◦ C within 20 minutes. The effects of various operational parameters such as the pH and the amounts of catalysts on the sonochemical degradation were also investigated. US alone were found to be totally ineffective for bleaching the dyes. Sonochemical degradation of DB71 was strongly affected by the amounts of catalysts and the pH level. However, acidic pH was favoured for the sonocatalytic degradation of DB71 using catalysts. The ultrasonic degradation of dye was enhanced by catalysts addition. Accordingly, removal of 55.8% dye colour  was achieved with 1 gL − 1 of catalyst, 2.5 pH, 50 mgL -1 and 20°C, during 20 minutes. The effect of H 2 O 2 on sono, photo and sonophotocatalytic oxidations was investigated at these optimum conditions. It was observed that the colour removal efficiency was influenced by the solution H 2 O 2 . The highest colour removal was obtained as 78% by US/UV/ZVC/H 2 O 2 .

No abstract is provided for this article.

Skin cancer is one of the most common type of cancer in humans. This type of cancer is produced by skin cells called melanocytes and occurs as a result of division and multiplication of the mentioned cells. The most important symptom of skin cancer is the formation of spots on the skin or the observation of changes in the shape, color, or size of the existing spot. It is necessary to consult a specialist to distinguish the difference between a normal spot and skin cancer. Expert physicians examine and follow up the spots on the skin using skin surface microscopy, called dermatoscopy, or take a sample from the suspicious area and request it to be examined in laboratory environment. This situation increases the cost of the procedure for the diagnosis of skin cancer and also causes it to be treated at a later stage. Therefore, there is a need for a metod that can detect skin cancer early. Thanks to machine learning, become popular in recent years, many diseases can be diagnosed with software that helps expert physicians. In this study, VGGNet model structures (VGG-11, VGG-13, VGG-16, VGG-19) that quickly classify skin cancer and become a traditional convolutional neural network architecture using deep learning method, a subfield of machine learning, were used. It has been observed that the VGG-11 architecture, which is one of the VGGNet model structures, detects skin cancer with superior success accuracy (83%) compared to other model structures.

Çalışmada, genel tarama yöntemlerinden doküman analizi yöntemi ile Âşık Paşa’nın Garib-nâme’sinde tespit edilen Eski Anadolu Türkçesi dönemine ait karakteristik ses ve şekil özellikleri incelenecektir. Âşık Paşa’nın Anadolu sahasında bir yazı dilinin oluşmasındaki etkileri Eski Anadolu Türkçesi dönemine özgü kabul edilen özellikler temelinde ortaya konulacak, Türk dilinin Anadolu’da gelişimindeki katkısı açıklanacaktır. Anadolu’da bir yazı dilinin oluşmasında Mevlâna, Ahmed Fakih, Şeyyad Hamza, Yunus Emre, Sultan Veled, Hoca Dehhâni, Gülşehrî, Hoca Mesud, Ahmedî ve Nesimî gibi şahsiyetlerle beraber önemli bir yeri olan Âşık Paşa’nın ve onun on binden fazla beyitten oluşan mesnevisinin ses ve şekil özellikleri bakımından döneme ışık tutacağı açıktır. Halkı dinî ve tasavvufi olarak yetiştirirken Türk dilini kullanmadaki hassasiyetini beyitlerinde dile getiren Âşık Paşa, Hakk’ı ve hakikati “Türk dilinde” anlattığını özellikle dile getirir. Bu bakımdan edebî değerinin yanında temel bir yazı felsefesine sahip olan Garib-nâme’nin ve onun gramer şekillerinin Türk diline önem veren bir yazarın kaleminden çıktığı açıktır. Bu da yazarın ve bu önemli eserinin Oğuzca ses ve şekil özelliklerine en doğru şekilde kaynaklık edeceğini gösterir. Bu çalışma ile Âşık Paşa’nın Garib-nâme’sinde tespit edilecek Oğuz diline ait ses ve şekil özellikleri, dönem yazı dili üzerine önemli veriler ortaya koyacaktır.

In this paper, speed and direction angle of a four wheel skid-steered mobile robot (4 WD SSMR) has been controlled via adaptive-fuzzy fractional-order sliding mode controller (AFFOSMC) under different speed and angle reference signals. The hybrid control method is designed to combine all advantages that controllers have such as flexibility realized by fractional order calculation, robustness to disturbances and parameters variations provided by sliding mode controller (SMC) as well as adaptation of G constant of SMC via fuzzy controller, simultaneously. Also, a fractional-order SMC is applied to the system for the same reference speed and angle references to show the effects of the changes and adaptation of G constant. Experimental results show that the AFFOSMC has better trajectory tracking performance than the FOSMC.DOI: http://dx.doi.org/10.5755/j01.eie.24.2.20630