244 publications from this institution
Cancer is a disease in which cells acquire autonomous growth, genetic instability, and significant metastatic strength, and is considered one of the most common causes of death worldwide. The most important types of cancer-causing these deaths are lung and colon cancers. Although they are rarely seen at the same time, the rate of metastasis of cancerous cells between these two organs is quite high if not diagnosed early. Histopathological diagnosis and appropriate treatment are the only ways to distinguish cancer types and reduce cancer death rates. The use of artificial intelligence in histopathological diagnosis can also provide experts with significant assistance with less effort, time, and cost. In this study a dataset, containing 25000 histopathological images belonging to 5 classes to classify colon and lung cancer types, was used. In order to obtain successful classification results from this dataset, the versions of the DenseNet algorithm, one of the deep learning algorithms, (DenseNet121, DenseNet169, and DenseNet201) were used firstly. Then, 3 novel models (DenseNet121_Improved, DenseNet169_Improved, and DenseNet201_Improved) were proposed by adding a cut-point layer, an auxiliary layer, and making frozen status improvements to the versions of the DenseNet algorithm. Versions of the DenseNet algorithm and proposed models were trained with stratified k-fold cross-validation technique first on colon cancer containing 2-class histopathological images, then lung cancer containing 3-class histopathological images, and lastly on 5-class histopathological images containing both colon and lung cancer. Finally, classification success rates were obtained. According to the experimental results performed on 3 different datasets, 97.60%, and 98.48% classification success rates in the lung cancer dataset and in both colon and lung cancer datasets were obtained respectively. The best classification success rate was achieved with DenseNet201_Improved, which was recommended with 99.80% in the colon cancer dataset.
No abstract is provided for this article.
Classification and monitoring of microalgae species in aquatic ecosystems are important for understanding population dynamics. However, manual classification of algae is a time-consuming method and requires a lot of effort with expertise due to the large number of families and genera in its classification. The recognition of microalgae species has become an increasingly important research area in image recognition in recent years. In this study, machine learning and deep learning methods were proposed to classify images of 12 different microalgae species in order to successfully classify algae cells. 8 Different novel models (MobileNetV3Small-Lr, MobileNetV3SmallRf, MobileNetV3Small-Xg, MobileNetV3Large-Lr, MobileNetV3Large-Rf, MobileNetV3Large-Xg, MobileNetV3Small-Improved and MobileNetV3Large-Improved) have been proposed to classify these microalgae species. Among these proposed model structures, the best classification accuracy rate was 92.22% and the loss rate was 0.72, obtained from the MobileNetV3Large-Improved model structure. In addition, as a result of the experimental results obtained, metrics such as the confusion matrix, which can meet the experts in the correct diagnosis of microalgae species, were also evaluated. This research may in the future open a new avenue for the development of a cost-effective, highly sensitive computer-based system for the use of image analysis and deep learning techniques for the identification and classification of different microalgae.
Flexible pavements are considered more sustainable than concrete pavements primarily due to the higher long-term maintenance and rehabilitation costs associated with concrete pavements. Concrete pavements possess a higher modulus of elasticity, which allows them to distribute vehicle loads over a larger area, thereby enhancing the strength of the pavement. However, despite this advantage, their flexural strength is relatively low. As a result, there has been a growing focus on research to improve the flexural strength of concrete pavements to increase their overall performance and sustainability. This study aimed to reveal the effects of enhanced mechanical properties of concrete reinforced with glass fiber on concrete pavements, specifically under heavy vehicle loading as in real-world conditions. The impact of glass fiber on the thickness of both the concrete and base layers, as well as the quality of the base layer material and transverse joint spacing, was assessed. For this purpose, 3D finite element models were developed using ANSYS software, considering concrete thicknesses of 100, 150, and 200 mm, glass fiber ratios of 0%, 0.5%, and 1%, base layer elastic moduli of 100, 200, and 300 MPa, and transverse joint spacings of 300, 450, and 600 mm. It was determined that the concrete thickness and the base layer modulus of elasticity were the most influential factors in minimizing flexural stress, total deformation, and equivalent total strain. The glass fiber addition had a more notable impact on maximum principal stress, especially at the 1% ratio, but had a minimal effect on total deformation and strain. Transverse joint spacing had the least effect, although shorter spacings are still recommended to reduce the risk of transverse cracking in stiffer base layers.
This study investigated color and COD removal of azo dye Direct Blue 71 (DB71) by a Fenton-like process in zero-valent iron (Fe 0 = ZVI).The UV-vis spectra of DB71 exhibit three main absorption bands -two in the UV region and one in the visible region.UV-vis spectra showed that the azo linkages in the molecule structure of the dyes were destroyed during the decolorization.The influence of various operational parameters such as pH, ZVI dosages, hydrogen peroxide (H 2 O 2 ) concentrations and temperature are studied to determine the optimum conditions for color and COD removal.pH is highly effective parameter of decolorization and COD destruction in this work.However, H 2 O 2 concentration and ZVI dosages were not only effective in the removal of COD for 100 mgL -1 initial DB71 concentration.Therefore, the optimum ZVI:H 2 O 2 ratio is based on determining the value of COD removal.Optimum conditions were accepted to be pH of 2.5, ZVI:H 2 O 2 ratio 4:1 and 20ºC temperature.The result indicated that 100% of decolorization efficiency was achieved within 20 min in the range of 150-400 mg/L initial DB71 concentrations by using optimal conditions.Residual COD values were 15.38, 22.35, 22.58, 27.04, 31.86 mg/L for 150, 200, 250, 300, 400 mg/L initial DB71 concentrations at the end of reaction time, respectively.Additionally, increasing the reaction temperature from 20 to 40ºC negatively affected the decolorization and degradation rate DB71.The experimental kinetic data are fitted very well the Behnajady-Modirshahla-Ghanbery model for color removal of DB71 dye.
The high costs and environmental damage in conventional concrete production have led researchers to search for alternative materials. The aim of the studies carried out in this context is to improve the material mechanical properties of concrete and to progressive economical products. When the existing literature is examined; the changing material mechanical properties of concrete have been examined by adding materials such as fly ash, blast furnace slag, waste rubber, steel wire and plastic fiber in different volumetric ratios to concrete or by using light, sustainable and economical materials such as natural perlite instead of conventional aggregate in the concrete ingredient. The bond-reinforcement slip relationship between reinforcement bar and concrete depends on many factors such as concrete compression level, bar diameter, embedment depth, and concrete void structure. In this study; it was aimed to investigate the effect of concrete compression level, concrete cover and perlite usage parameters on the bond-reinforcement slip relationship between reinforcement bar and concrete by producing a total of 24 cube samples with 20 MPa and 40 MPa compressive strength and 2.0 mm and 4.0 mm concrete cover using conventional aggregate and natural perlite aggregate. From the research to be conducted; it is expected that the bond strength of conventional concrete and natural perlite concrete will be improved by increasing the concrete compressive strength and concrete cover parameters.
Sızıntı suları, kompleks yapıları ve yüksek kirletici konsantrasyonlarından dolayı arıtımı zor atık sulardır. Bu çalışmada; sızıntı sularından Fenton-benzeri oksidasyon ile renk ve kimyasal oksijen ihtiyacı (KOİ) giderimi çalışılmıştır. Renk ve KOİ giderimine sıfır değerlikli demir (ZVI) ve H 2 O 2 konsantrasyonunun etkisi incelenmiştir. Renk giderimi 436, 525 ve 620 nm olmak üzere farklı üç dalga boyunda değerlendirilmiştir. En yüksek KOİ (%74.4) ve renk giderimi (436 nm’de %71, 525 nm’de %80.3 ve 620 nm’de %87.9) 0.05 g/L ZVI konsantasyonunda belirlenmiştir. 200 mg/L H 2 O 2 konsantrasyonuna kadar artan H 2 O 2 konsantrasyonu ile renk ve KOİ gideriminin de arttığı gözlenmiştir. Optimum değerler; 20 dakikalık bir reaksiyon süresinde ve pH=2.0’de ZVI=0.05 g/L, H 2 O 2 =150 mg/L olarak bulunmuştur. Ulaşılan optimum şartlarda toplam organik karbon (TOK) giderimi %50 civarında belirlenmiştir.
Bu calismada, Acid Yellow 36 (AY36) boyar maddesinin Fenton ve Fenton-benzeri oksidasyon yontemi ile giderimi arastirilmistir. Oksidasyon prosesine pH, demir (Fe 0 ve Fe +2 ), hidrojen peroksit (H 2 O 2 ) ve boyar madde konsantrasyonunun etkisi incelenmistir. AY36 giderimi renk, aromatiklik ve KOI uzerinden izlenmistir. Fenton ve Fenton-benzeri oksidasyonunda renk aromatiklikten daha fazla giderilmistir. AY36 boyar maddesinin gideriminde, Fenton-benzeri oksidasyonun Fenton oksidasyon prosesinden daha etkili oldugu bulunmustur.
Abstract The degradability of an azo dye, Basic Blue 9 (BB9), by heterogeneous sonocatalytic, photocatalytic, and sonophotocatalytic oxidation process was examined using simultaneous irradiation of UV‐C at 254 nm and power ultrasound at 20 kHz accompanied with a heterogeneous catalyst zinc oxide (ZnO) in the study. The effect of ZnO dose and initial dye concentration was investigated on the dye degradation in sonocatalytic, photocatalytic, and sonophotocatalytic processes at pH 5.5 (natural pH). The results obtained from the experimental studies were evaluated with the parameters of color removal, pseudo‐first‐order rate constant, and half‐life time. It was observed that the degradation of BB9 dye by the sonophotocatalytic process was higher compared to both sonocatalytic and photocatalytic degradation. as follows: 97.46, 48.64 and 56.88 %. The combination of sono and photocatalytic showed a remarkable synergistic effect in BB9 degradation. The kinetics of sonophotocatalytic oxidations, depending on the initial BB9 dye concentration, were found to follow the Langmuir‐Hinshelwood model. In addition, the effect of ZnO on the sonophotocatalytic oxidation process was higher compared to titanium dioxide and zero‐valent iron as follows: 97.47, 80.77 and 80.62 %.
Research was conductedto investigate the performance of phase change material (PCM) walls for solarspace heating. The PCM walls were consisted of brick walls, plasterboardscontaining PCMs and novel triple glazing units. South façade of atest room was constructed using the PCM walls for heating the test room with solar thermal energy. The overall efficiency of the PCMwalls was experimentally determined on a monthly basis. Inaddition to experimental analysis, a theoretical energy analysis of the PCMwalls based on 10-year mean meteorological data was performed to provide a moregeneral conclusion about the performances of the PCM walls. Besides, reductionin CO2 from the test room owing to PCM wall was also calculated.Theoretical analysis results showed that, the reduction of CO2emission on a monthly basis varied from 57 to 7% during the heatingperiod. Heating period is from Octoberthrough May. Reduction of CO2 emission was 16% on an annual basis.
Korozyona maruz kalmış betonarme yapılarının deprem performanslarının daha doğru bir şekilde değerlendirilmesi için yeni yöntem ve deneysel sonuçlardan elde edilecek verilere ihtiyaç duyulmaktadır. Korozyon beton içerisinde paslanan betonarme donatısının kesit alanının azalmasına neden olurken beraberinde aderans kaybı gibi önemli sorunlara da neden olmaktadır. Aderans kaybı ise donatı sıyrılmasına sebebiyet vererek ek yanal deplasmanların oluşmasına neden olabilmektedir. Ancak mevcut alan yazında literatürde tam ölçekli paslandırılmış betonarme elemanları üzerine yeterli deneysel veriler olmadığından korozyonun etkisi yapı performansı değerlendirmelerinde yalnızca donatı çapındaki azalma olarak alınmaya devam etmektedir. Bu çalışmada tam ölçekli betonarme kirişleri farklı pas oranlarında eğilme deneylerine tabi tutularak mevcut alan yazına veri sağlanması amaçlanmıştır deneysel elde edilen yük-deplasman ilişkileri; artan korozyon oranı, donatı çapındaki azalma, hızlandırılmış korozyon yöntemi sırasında meydana gelen birincil çatlaklar, donatı üzerindeki nervürlerin hasar görmesi ve buna bağlı olarak radyal sürtünme kuvvetindeki azalımın neden olduğu aderans kayıpları gibi parametreler açısından tartışılmıştır. Beş adet betonarme kirişi hızlandırılmış korozyon yöntemi kullanılarak paslandırılmıştır. Betonarme kirişlerindeki gerçek korozyon oranları eğilme deneylerinden sonra betonarme kirişlerinin kırılarak ve içerlerinden betonarme donatılarının çıkartılması ile elde edilmiştir. Yapılan deneysel çalışma sonucunda korozyon oranının %3 değerlerinde yapı elemanlarında sünekliği arttığı ancak artan korozyon oranına bağlı olarak nihai yük taşıma ve süneklik değerlerinde azalmalara sebebiyet verdiği bulunmuştur. Aynı korozyon oranına sahip iki farklı betonarme kirişindeki eğilme davranışlarının farklılığı, sargı donatılarındaki farklı korozyon oranları ile tespit edilmiştir. Elde edilen deney sonuçları, korozyona maruz kalmış betonarme yapılarda aynı korozyon oranı kabulü yerine korozyon haritalandırma yöntemlerinin mevcut yapıların daha doğru değerlendirilmesi için geliştirilmesi gerektiğini ortaya koymuştur.
Ductile behavior is one of the most important earthquake indicators that must be possessed by structures. Because of the limited tensile strength of concrete, alternative materials such as structural nanosynthetic fibers as three-dimensional reinforcement bars have gained increasing popularity over several decades. However, the contribution of fibers to the development length of reinforcement bars has not been investigated. Therefore, an experimental study was conducted to investigate the effects of polypropylene fibers on the development lengths of reinforcement bars. Thirty-three reinforced concrete (RC) slabs at three different volume fractions of fibers of 0.0, 1.0 and 1.5 % at different embedment lengths of reinforcement bars were investigated under four-point flexural strength tests. Load-displacement curves, energy absorption capacities, ductility ratios and bond-slip relationships were obtained for different embedment lengths of reinforcement bars with three different amounts of fibers in RC concrete slabs. The test results revealed that the predominant effects of fibers on structural behavior pertained to the energy absorption capacities at plastic deformation. It was found that resisting more strains by reinforcement bars with the help of added polypropylene fibers resulted in the regaining of ductile behavior due to the reduced embedment lengths of the reinforcement bars.
Compressive strength and modulus of elasticity of concrete are two important properties involved in the design of reinforced concrete members and sections. The main objective of this investigation was to investigate the effect of fiber aspect ratio (1/d) and fiber volume on the compressive strength and modulus of elasticity of fiber reinforced concrete (FRC), and to study the relationship between compressive strength and modulus of elasticity of FRC. in this investigation, 19 fiber reinforced concrete mixes were produced by adding three different hooked-end steel fibers of aspect ratio of 60, 75, and 83 and also six different volumes of fibers namely 0.5, 1.0, 1.25, 1.5, 1.75, and 2.0 % by volume of concrete were added for each aspect ratio. As a result, good relationships between compressive strength of FRC and the fiber reinforcement index (FRI = Vr .1/d) between modulus of elasticity and FRI, and between compressive strength and modulus of elasticity of FRC were obtained.
