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Showing 1401 - 1205 of 1205 Journals sorted alphabetically
Transportation Research Record : Journal of the Transportation Research Board     Full-text available via subscription   (Followers: 34)
Transportmetrica A : Transport Science     Hybrid Journal   (Followers: 8)
Trends in Applied Sciences Research     Open Access   (Followers: 1)
Tribology in Industry     Open Access   (Followers: 4)
Tribology International     Hybrid Journal   (Followers: 46)
Tribology Letters     Hybrid Journal   (Followers: 7)
Tribology Transactions     Hybrid Journal   (Followers: 35)
Trilogía     Open Access  
Turkish Journal of Engineering     Open Access  
Turkish Journal of Engineering and Environmental Sciences     Open Access   (Followers: 1)
Türkiye Arazi Yönetimi Dergisi     Open Access  
Türkiye Coğrafi Bilgi Sistemleri Dergisi     Open Access  
Türkiye Fotogrametri Dergisi     Open Access  
Türkiye İnsansız Hava Araçları Dergisi     Open Access  
U.Porto Journal of Engineering     Open Access  
UKH Journal of Science and Engineering     Open Access  
Ultramicroscopy     Hybrid Journal   (Followers: 4)
Uludağ University Journal of The Faculty of Engineering     Open Access  
Uluslararası Mühendislik ve Teknoloji Araştırmaları Dergisi / International Journal of Engineering and Technology Research     Open Access  
Universal Journal of Applied Science     Open Access   (Followers: 2)
Universal Journal of Engineering Science     Open Access   (Followers: 2)
Universidad, Ciencia y Tecnología     Open Access   (Followers: 1)
Usak University Journal of Engineering Sciences     Open Access  
Utilities Policy     Hybrid Journal   (Followers: 2)
Vacuum     Hybrid Journal   (Followers: 12)
Vestnik of Don State Technical University     Open Access  
Vibration     Open Access   (Followers: 19)
Virtual and Physical Prototyping     Hybrid Journal   (Followers: 4)
Visualization in Engineering     Open Access   (Followers: 1)
Walailak Journal of Science and Technology     Open Access  
Waste and Biomass Valorization     Hybrid Journal   (Followers: 3)
Waste Management Series     Full-text available via subscription   (Followers: 1)
Waves in Random and Complex Media     Hybrid Journal  
Waves, Wavelets and Fractals - Advanced Analysis     Open Access  
Wear     Hybrid Journal   (Followers: 27)
Welding in the World     Hybrid Journal   (Followers: 7)
West African Journal of Industrial and Academic Research     Open Access   (Followers: 2)
World Electric Vehicle Journal     Open Access  
World Journal of Engineering and Technology     Open Access  
World Journal of Environmental Engineering     Open Access   (Followers: 3)
World Pumps     Full-text available via subscription   (Followers: 2)
World Science and Technology     Full-text available via subscription  
Yugra State University Bulletin     Open Access   (Followers: 1)
ZDM     Hybrid Journal   (Followers: 1)
Zede Journal     Open Access   (Followers: 1)
Zeitschrift für Arbeitswissenschaft     Hybrid Journal  
Zeitschrift fur Energiewirtschaft     Hybrid Journal  
Вісник Приазовського Державного Технічного Університету. Серія: Технічні науки     Open Access  

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Uludağ University Journal of The Faculty of Engineering
Number of Followers: 0  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2148-4147 - ISSN (Online) 2148-4155
Published by Uludağ University Homepage  [8 journals]
  • Reviewer List of 2016

    • Authors: Osman Kopmaz
      PubDate: 2017-03-14
      Issue No: Vol. 21, No. 2 (2017)
       
  • Weaknesses and Suggestions of the Provisions of Fire Protection
           Regulations of Health Constructions

    • Authors: Zuhal ŞİMŞEK, Nilüfer Emine AKINCITÜRK
      Abstract: Healthcare buildings, require special arrangements in two separate areas like to ensure the evacuation strategy depends on the users mobility and including measures that can be taken against places of high risk of fire, in the step of providing fire safety. Unfortunately, there aren’t adequate regulations taking place for places of high fire risk and evacuation strategies of patients in the "Regulation on Fire Protection in Buildings’  in Turkey. But, NFPA standards (National Fire Protection Association, USA) and International Building Standards used in the UK "Building Regulations", UK.) contained related issues of regulations.  In this working it is aimed to complete of the weaknesses in our regulations as a result of comparing the regulations of N.F.P.A. and B.R with fire safety regulations of Turkey and to ensure the fire safety of buildings in the best way in this direction. It is believed that  the losses  and occurance of fire can be decreased by organizing of special measures relating to patient evacuation and risky places
      PubDate: 2016-12-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • Investigation of Performance and Emissions Effects of Waste Vegetable Oil
           Methyl Ester in A Diesel Engine

    • Authors: Yahya ULUSOY
      Abstract: In this study engine and emission performance of a 4-stroke, 4 cylinder, direct injection 62,5 kW engine, with three different biodiesel blends (B25, B50, B75),  was compared with those obtained with use of normal diesel (B0) through a 8-mode experimental test procedure, in convention with ISO 8178-C1. The results of the study showed that, performance and emission values of biodiesel fuels produced from vegetable oil and those obtained with diesel fuel (B0) are very close to each other.  In this context, the waste cooking oil, which is a serious risk to the environment and should be collected according to related legistlative measures,  could be processed to and used as biodiesel without creating any significant loss in terms of engine performance, while providing significant advantages in terms of engine emissions. These results revealed that, waste frying oils can be used as diesel fuel and to create an adding value for the economy instead of being potential environmental risk. 
      PubDate: 2016-12-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • Evaluation of Empirical Modelling Techniques for the Estimation of
           Sediment Amount in Rivers

    • Authors: Başak GÜVEN, Zeynep AKDOĞAN
      Abstract: The sediment transport processes of streams have been the subject of research for many years. Sediment amount carried by a river is strongly correlated with the river’s flow rate and sediment concentration. This study aims to represent this correlation and to estimate the sediment amount using four different modelling techniques: MLR, PLS, SVM, and ANN. Records of river flow, sediment concentration and sediment amount obtained from the Göksu River, located in the Eastern Mediterranean region of Turkey, are used as input data in the models. The aim of is this study is to evaluate the effectiveness of ANN modelling in the estimation of sediment amount carried by river flow. Fifty percent of the data are used as training set to develop the models. The other half of the data is used for verification set. The performance of the four models is evaluated by determination coefficient of prediction set (r2pred). The results indicate that ANN is the most effective method (r2pred = 0.94), followed by SVM (r2pred = 0.72). MLR and PLS methods are the least effective techniques (r2pred = 0.67) for estimating sediment amount in the Göksu River. Therefore, ANN approach is further studied to propose the best configuration for the prediction of river sediment amount.
      PubDate: 2016-12-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • A Decision Support System for Determination of Fetal Well-Being from
           Cardiotocogram Data

    • Authors: Ersen YILMAZ
      Abstract: In this study, we propose a decision support system for assessment of fetal well-being from cardiotocogram data. The system is based on Principal Component Analysis and Least Squares Support Vector Machines. Principal Component Analysis is used for feature reduction of the cardiotocogram data set. Classification of the data set with reduced features is made by using Least Squares Support Vector Machines. Performance analysis of the proposed system is examined on the cardiotocogram data set availabe on UCI Machine Learning Repository by using 10-fold Cross Validation procedure. Experimetal results show that the proposed system has %98,74 classification accuracy, %98,86 sensitivity and %98,73 specificity rates.
      PubDate: 2016-12-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • Analyzing Urban Transformation Policies in Turkey Over Implementations
           Conducted in Cooperation with TOKİ: Case of Bursa

    • Authors: Miray GÜR
      Abstract: In the study, urban transformation matter which is a significant agenda item in Turkey planning policies because of the recent implementations and the legal infrastructure developed in 2012 is analysed with its physical, social and organizational dimensions.  The method used in the study is reaching general conclusions through the examinations that are done by focusing on determined samples and the centralized management of the implementations countrywide, with the monopolistic production approach provides this generalization. In the study which analyzes the evolving of urban transformation in Western countries and Turkey after remarking some opinions about structuring of urban transformation, the changing role and the targets of TOKİ in this framework beginning from 2000’s in Turkey are discussed. Within the context of case study, the urban transformation projects implemented by TOKİ in Bursa, having a significant situation in urban transformation strategies of Turkey, are discussed with its physical and social dimensions and the findings discovered are evaluated with different extents in the last chapter of the study. Through the evaluation made, some suggestions are developed for turning the centralized management into an advantage, making the transformation implementations fall within the urban entirety, provide social entegration, contribute to the city construct that is contemporaneous having a genious identity and to raise the communal quality of life by transformations.
      PubDate: 2016-12-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • On the Calibration of Multigene Genetic Programming to Simulate Low Flows
           in the Moselle River

    • Authors: Ali DANANDEH MEHR, Mehmet Cüneyd DEMIREL
      Abstract: The aim of this paper is to calibrate a data-driven model to simulate Moselle River flows and compare the performance with three different hydrologic models from a previous study. For consistency a similar set up and error metric are used to evaluate the model results. Precipitation, potential evapotranspiration and streamflow from previous day have been used as inputs. Based on the calibration and validation results, the proposed multigene genetic programming model is the best performing model among four models. The timing and the magnitude of extreme low flow events could be captured even when we use root mean squared error as the objective function for model calibration. Although the model is developed and calibrated for Moselle River flows, the multigene genetic algorithm offers a great opportunity for hydrologic prediction and forecast problems in the river basins with scarce data issues.
      PubDate: 2016-12-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • Putting Urban Regeneration Projects in Order: An Example of a Decision
           Support System

    • Authors: Ayşegül ALAYBEYOĞLU, Uğur KILIÇ, Ayşe İREGÖL, Yunus KONBUL
      Abstract: There is an urgent need of renewal of metropolitan cities in Turkey which heavily consist of irregular, low quality building stock which have occurred in the last 60 years. However urban regeneration projects are large and expensive construction projects. Therefore, due to technical and economic barriers, it is not possible for regeneration authorities to start the projects for the whole city in the same time. Thus they carry out projects step by step, one after another. Projects are started from the most problematic and urgent ones to the least problematic ones. However, regeneration authorities face with problems when putting regeneration projects in order, i.e. determining which neighborhood should be regenerated earlier than the other one. In addition to that, they are having difficulties when explaining their decisions to the public. At this point, a computer-based Fuzzy Logic decision support system can help them reach more convenient decisions. Also, with this way, the decisions will have a scientific basis, therefore it can be easier to announce them to the public and avoid speculation. In this paper, an example of a decision support system based on Fuzzy Logic for putting urban regeneration project areas in order was presented.
      PubDate: 2016-12-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • Use of Different Bulking Agents and Inoculation Agent in Composting of
           Food Industry Process Wastes

    • Authors: Selnur UÇAROĞLU, Behice Gamze GÜMRAH
      Abstract: The aim of this study was to investigate the compostability of food industry process wastes with different bulking agents for disposal and recovery, and to determine the effect of treatment sludge which was used as inoculation agent. Sunflower stalk and corn cob were mixed to process wastes as bulking agents. Four different compost mixtures were prepared to investigate composting of process wastes. Process wastes and sunflower stalk to first mixture (M1) at ratio of 3:2; process wastes, treatment sludge and sunflower stalk to second mixture (M2) at ratio of 3:1:2; process wastes, treatment sludge and corn cob to third mixture (M3) at ratio of 3:1:2; process wastes, treatment sludge and corn cob to fourth mixture (M4) at ratio of 3:1:3 were added. M1 mixture was prepared without inoculation agent as control mixture.  Temperature, dry matter content, organic matter loss, C/N ratio, pH and electrical conductivity parameters were monitored during the composting process for 28 days. The highest organic matter losses and the highest temperature formed in the process were monitored in M3 reactor. According to the results, for the efficiently composting process; process wastes with treatment sludge as inoculation agent and corn cob as bulking agent at ratio of 3:1:2 were determined.
      PubDate: 2016-12-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • Hydrothermal Treatment of Cellulose in Hot-Pressurized Water for the
           Production of Levulinic Acid

    • Authors: ASLI YUKSEL
      Abstract: In this paper, hot-pressurized water, operating above boiling point and below critical point of water (374. 15 °C and 22.1 MPa), was used as a reaction medium for the decomposition of cellulose to high-value chemicals, such levulinic acid. Effects of reaction temperature, pressure, time, external oxidant type and concentration on the cellulose degradation and product distribution were evaluated. In order to compare the cellulose decomposition and yields of levulinic acid, experiments were performed with and without addition of oxidizing agents (H2SO4 and H2O2). Analysis of the liqueur was monitored by HPLC and GC-MS at different temperatures (150 - 280 °C), pressures (5-64 bars) and reaction times (30 - 120 mins). Levulinic acid, 5-HMF and formic acid were detected as main products. 73% cellulose conversion was achieved with 38% levulinic acid yield when 125 mM of sulfuric acid was added to the reaction medium at 200 °C for 60 min reaction time.
      PubDate: 2016-12-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • Investigation of the Effects of the Magnetic Circuit Design Parameters on
           the Electromechanical Valve Actuators

    • Authors: Zeliha KAMIŞ KOCABIÇAK, Elif ERZAN TOPÇU
      Abstract: The paper describes the suitable type of magnetic circuits used in the electromechanical valve actuators (EVAs). Two different types of EVA models with the disc type of magnetic circuits were designed and the effects of various design parameters such as spring constant, moving mass, supply voltage, holding force on the system were investigated. The static and dynamic equations of the system were derived and their numerical solutions were obtained with MATLAB/Simulink program. The detailed theoretical analysis and experimental tests were carried out on the manufactured different prototypes of the EVAs. Simulation and experimental results showed a good agreement with each other. 
      PubDate: 2016-12-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • Detection of P53 Consensus Sequence: A Novel String Matching With Classes
           Algorithm

    • Authors: Gıyasettin ÖZCAN
      Abstract: We present a novel fast string matching technique for special DNA pattern forms and compare performance of recent CPU architectures on the matching problem. In particular, we consider consensus P53 DNA-binding consensus sequence, which has an important contribution for cancer treatment. Based on biological findings, consensus P53 pattern may emerge in various sequence forms and its length is not deterministic. Therefore, classic string matching algorithms are not able to solve the problem. For efficient solution, we consider bitwise string matching algorithms with classes and present a novel search technique which is based on 64-bit packed variables. In order to prevent obstacles based on variable length of the pattern, we search specific indexes of P53 on databases. For experimental analysis, we make use of mus musculus DNA sequences with approximately 2.3 billion nucleotides. We compare algorithm performance and three architectures with various level CPU parallelism. Test results show that our technique presents search efficiency during P53 pattern search in each architecture platform. Due to its structure, the algorithm also introduces an efficient solution to similar string matching with class problems.
      PubDate: 2016-12-08
      Issue No: Vol. 21, No. 2 (2016)
       
  • Investigation of Influence of Membrane Type on Water Recovery by
           Pressurized Membrane Processes from Textile Washing Wastewaters

    • Authors: Coskun AYDINER, Berna KİRİL MERTt, Esra CAN DOĞAN, Esin BALCİ, Yasemin Melek TİLKİ, Seyda AKSU, Aysegul Yagmur GÖREN
      Abstract: Developments in industrial activities around the world lead to increase water consumption and to become widespread industrial water pollution problems. This situation accompanied by increasing water shortage issues needs to be realized technological applications which include recovering water in reusable quality from wastewaters of excessive water-consuming industries. In this study, recovering water in reusable quality from textile washing wastewaters having 6.22±0.03 pH, 1130±321 mg TDS/L, 2362±727 mg COD/L and 744±234 mg TOC/L was aimed using ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membrane processes. In this respect, effect of membrane type as the main parameter for real-scale installations on reusable water quality was examined. Experiments were performed using four membranes each for UF and NF and five for RO at the conditions of original pH, 25 ºC and 300 rpm cross-flow rate in trans-membrane pressures of 8, 12 and 40 bar for UF, NF and RO, respectively. At the experiments, the best performances were obtained by UH050, NF270 and LFC-3 membranes for the aforementioned order of the processes. This study was proved that reuse water with pH 6.34, 13 mg TDS/L, 34 mg COD/L and 14 mg TOC/L could be produced from textile washing wastewaters using UF/NF/RO combined system.
      PubDate: 2016-11-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • COMPUTER-AIDED DETECTION OF BRAIN TUMORS USING MORPHOLOGICAL
           RECONSTRUCTION

    • Authors: Buket DOĞAN, Seda KAZDAL ÇALIK, Önder DEMİR
      Abstract: Computer aided detection (CAD) systems helps the detection of abnormalities in medical images using advanced image processing and pattern recognition techniques. CAD has advantages in accelerating decision-making and reducing the human error in detection process. In this study, a CAD system is developed which is based on morphological reconstruction and classification methods with the use of morphological features of the regions of interest to detect brain tumors from brain magnetic resonance (MR) images. The CAD system consists of four stages: the preprocessing, the segmentation, region of interest specification and tumor detection stages. The system is evaluated on REMBRANDT dataset with 497 MR image slices of 10 patients. In the classification stage the performance of CAD has achieved accuracy of 93.36% with Decision Tree Algorithm, 94.89% with Artificial Neural Network (Multilayer Perceptron), 96.93% with K-Nearest Neighbour Algorithm and 96.93% with  Meta-Learner (Decorate) Algorithm. These results show that the proposed technique is effective and promising for detecting tumors in brain MR images and enhances the classification process to be more accurate. The using morphological reconstruction method is useful and adaptive than the methods used in other CAD applications.
      PubDate: 2016-11-28
      Issue No: Vol. 21, No. 2 (2016)
       
  • Investigation of Airfoil Aeroacoustics with Blowing Control Mechanism

    • Authors: Baha ZAFER, Salih GÜRSOY
      Abstract: In this investigation, it is dealt with computational aero-acoustic analysis of an airfoil with jet blowing. The airfoil shape is selected as NACA0015 profile with jet blowing on upper surface. The calculations of analysis are done by using commercial finite volume solver. The k-ε turbulence model is used for the turbulence modeling and the Ffowcs Williams and Hawking acoustic analogy model is run for determination of acoustic data. The numerical results are compared with experimental data for computed Sound Pressure Level without jet blowing and well agreement is observed. In the case of jet blowing, the effects of different jet angle, velocity ratio and angle of attack on airfoil are investigated and noise levels of non jet cases and jet blowing cases are studied.
      PubDate: 2016-11-11
      Issue No: Vol. 21, No. 2 (2016)
       
  • Effect Of Ethylene Oxide, Autoclave and Ultra Violet Sterilizations On
           Surface Topography Of Pet Electrospun Fibers

    • Authors: Sebnem DUZYER, Asli HOCKENBERGER, Agah UGUZ, Elif EVKE, Zeynep KAHVECİ
      Abstract: The aim of this study to investigate the effects of different sterilization methods on electrospun polyester. Ethylene oxide (EO), autoclave (AU) and ultraviolet (UV) sterilization methods were applied to electrospun fibers produced from polyethylene terephthalate (PET) solutions with concentrations of 10, 15 and 20 wt.%. The surface characteristics of the fibers were examined by scanning electron microscope (SEM), atomic force microscope (AFM), surface pore size studies and contact angle measurements. Differential scanning calorimetry (DSC) tests were carried out to characterize the thermal properties. Fourier Transform Infrared spectroscopy (FTIR) tests were performed to analyze the micro structural properties. SEM studies showed that different sterilization methods made significant changes on the surfaces of the fibers depending on the PET concentration. Although the effects were decreased with the increasing polymer concentration, the fiber structure was damaged especially with the EO sterilization. The contact angle values were decreased with the UV sterilization method the most.
      PubDate: 2016-11-03
      Issue No: Vol. 21, No. 2 (2016)
       
  • Effects of Ultrasonic Disintegration on the Characteristics of Paint
           Sludge from Automotive Industry

    • Authors: Güray SALİHOGLU, Elif AKCAN
      Abstract: The effects of ultrasonic pre-treatment (disintegration) on the characteristics of water-based paint sludge from automotive industries were investigated by monitoring the parameters such as pH, total organic carbon (TOC), soluble chemical oxygen demand (sCOD), and humidity loss. The influence of ultrasonication duration and intensity over the monitoring parameters was examined.The findings showed that ultrasonication increased the pH, TOC, sCOD and humidity loss levels of paint sludges. However, it was obvious that the intensity and duration of the sonication should be applied according to the sludge management method planned. Increasing the intensity of the sonication resulted in an increase in pH and sCOD levels, while decreased the TOC and loss of humidity levels. Similarly, when the duration of sonication increased, the pH and SCOD increased; TOC and loss of humidity decreased.
      PubDate: 2016-11-03
      Issue No: Vol. 21, No. 2 (2016)
       
  • Low Temperature Solid-State Synthesis and Characterization of LaBO3

    • Authors: Azmi Seyhun KIPÇAK
      Abstract: Rare earth (lanthanide series) borates, possess high vacuum ultraviolet (VUV) transparency, large electronic band gaps, chemical and environmental stability and exceptionally large optical damage thresholds and used in the development of plasma display panels (PDPs). In this study the synthesis of lanthanum borates via solid-state method is studied. For this purpose, lanthanum oxide (La2O3) and boric acid (H3BO3) are used for as lanthanum and boron sources, respectively. Different elemental molar ratios of La to B (between 3:1 to 1:6 as La2O3:H3BO3) were reacted by solid-state method at the reaction temperatures between 500°C - 700°C with the constant reaction time of 4 h. Following the synthesis, characterizations of the synthesized products are conducted by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and scanning electron microscope (SEM). From the results of the experiments, three types of lanthanum borates of; La3BO6, LaBO3 and La(BO2)3 were observed at different reaction parameters. Among these three types of lanthanum borates LaBO3 phase were obtained as a major phase.
      PubDate: 2016-11-03
      Issue No: Vol. 21, No. 2 (2016)
       
  • Effects of Potassium Permanganate on Sludge Disintegration and Improving
           with Ultrasonic Pre-treatment

    • Authors: Özlem DEMİR
      Abstract: Sludge disintegration destroys the sludge floc structure and releases the cell contents into the liquid phase to enhance the sludge anaerobic digestion. In the first stage of this study, the usage of potassium permanganate was investigated for sludge disintegration. The efficiency of the sludge disintegration was evaluated in terms of disintegration degree and  the optimum dose of potassium permanganate was determined. In the second stage of the study, the effects of specific energy variability on sludge disintegration were examined for ultrasonic frequency application. For this purpose, the range of 13021-78125 kJ/kgTS of specific energy were used for floc disintegration and the most suitable energy level was determined considering the soluble chemical oxygen demand. According to the results, after the addition of 500 mg/L potassium permanganate to the sludge and stirring during 20 minutes, 37,9 % of disintegration degree was obtained and determined as optimum value. The optimum soluble chemical oxygen demand value for ultrasonic application was obtained for 52083 kJ/kgTS and 20 minutes. In the third stage of the study, the optimal dose of potassium permanganate and optimum ultrasonic disintegration value were applied to the sludge together as a combined method. The results show that 66 of % disintegration degree was achieved for the combined application of potassium permanganate and ultrasonic disintegration.
      PubDate: 2016-10-20
      Issue No: Vol. 21, No. 2 (2016)
       
  • Analysis of Signal-to-Crosstalk Ratio Variations due to Four-Wave Mixing
           in Dense Wavelength Division Multiplexing Systems Implemented with
           Standard Single-Mode Fibers

    • Authors: Sait Eser KARLIK
      Abstract: In this paper, variation of the signal-to-crosstalk ratio (SXR) due to effects of four-wave mixing (FWM) has been analyzed on center channels of 5-, 7-, 9-channel dense wavelength division multiplexing (DWDM) systems implemented with G.652 standard single-mode fibers (SSMFs) for 12.5 GHz, 25 GHz, 50 GHz and 100 GHz equal channel spacing values. Center channels on such systems are the most severely impacted channels by FWM. Therefore, results obtained are the worst-case values for the DWDM system performance and important for system design. Simulations have been performed for systems using three different commercially available SMFs having different design parameter values for chromatic dispersion, dispersion slope, nonlinearity coefficient and attenuation coefficient which are all in the scope of the G.652 Recommendation of Telecommunication Standardization Sector of International Telecommunication Union (ITU-T) for SSMFs. In those simulations, under the impact of FWM, variation of SXR with variations in input powers, channel spacings and link lengths have been observed. Simulation results display the combined effect of the optical fiber and system design parameters on FWM performance of DWDM systems and give important clues for not only long-haul but also access network implementations of DWDM systems.
      PubDate: 2016-10-14
      Issue No: Vol. 21, No. 2 (2016)
       
  • Electrical and Electronical Waste Generation in Turkey: Bursa Case Study

    • Authors: Güray SALİHOĞLU, Aslıhan Ece KAHRAMAN
      Abstract: Electrical and electronical equipment that gradually take more place in our daily life, spend their service life in short times and become an e-waste problem to be solved.  Because of the hazardous components they contain, e-waste can cause environmental and human health threats if they are not properly managed. If they are managed properly, they can be a valuable raw material source, since they contain valuable metals such as copper, silver, gold, palladium and recyclable components such as plastics and metals. According to a research conducted in 2014, the global e-waste amount accounts to a source worth 52 billion $; however, only 16% of this source has been properly recycled. It is important to know the potential e-waste amount and the behaviors of people in the production of e-waste to realize a proper e-waste management in our country. The amount and property of electrical and electronic equipment and e-waste generation potential per person in Bursa was investigated in this study. A questionnaire was prepared and applied to a group of people including 31 families (100 person). The questions were to investigate the behaviors in the use, replacement, and management of electrical and electronical equipment. The findings showed that usage of lamps (fluorescent and others) were higher than the other equipment, and usage of mobile phones were found to be highest in terms of devices. It was also found that when the mobiles become e-waste since the owners do not want to use them, they are not just thrown away and kept at homes instead. E-waste generation potential of a person from the families investigated was estimated to be 8.14 kg/year.
      PubDate: 2016-10-13
      Issue No: Vol. 21, No. 2 (2016)
       
  • Technical and Economical Comparison of Plate, Shell and Tube and Miniature
           Pipe Type Heat Exchangers

    • Authors: Ahmet Serhan CANBOLAT, Burak TURKAN, Akın Burak ETEMOGLU, Muhiddin CAN, Atakan AVCI
      Abstract: Heat exchangers are devices which facilitate the exchange of heat between two fluids that are different temperatures in engineering applications. Heat exchangers are commonly used in practice in a wide range of applications such as space heating and air conditioning, power production, waste heat recovery and chemical processing engineering. In this study, plate, shell and tube and multiple mini-tube type heat exchangers for the same heat capacity, with the same hot and cold water inlet and outlet temperatures and the same hot and cold water mass flow rates are compared with the technical and economical point of view respectively. When the evaluation criteria is cost; multiple mini tube type heat exchanger is the most economic choise in comparison the other exchangers in long term. However, due to the different usage areas, different choices may be done.
      PubDate: 2016-10-13
      Issue No: Vol. 21, No. 2 (2016)
       
  • Effects of Different Reinforcements for Improving Mechanical Properties of
           Composite Materials

    • Authors: Mahmut BİNGÖL, Kadir ÇAVDAR
      Abstract: The traditional materials are inadequate to the needs of modern manufacturing such as high mechanical and technological properties. There is a conflict with the demands of high-strength and lightweight, however the composite materials with diverse reinforcements provide each of the requests. Therefore, the use of the composite materials in industrial applications has become increasingly necessary. Sheet Molding Compounds (SMC) is a production method which the thermoset polymer composite parts with high-strengths can be manufacture in series for many areas, including automotive.In this study, the mechanical properties of two different SMC materials were examined which obtained using woven glass fibers and nonwoven (random) fibers as reinforcements to increase strengths of the resulting material. The experimental results showed that the tensile strength of the SMC specimen with random fibers reached an average value of 67.58 MPa, but the average value of the specimen with woven glass fiber reinforcement in the same conditions and a weight ratio was reached up to 137.29 MPa. With this new material, the tensile strength values were increased approximately to double.
      PubDate: 2016-10-13
      Issue No: Vol. 21, No. 2 (2016)
       
  • An Evaluation of Fuel Consumption and Emission for Double Glazed Windows
           That Have Optimum Air Layer

    • Authors: Okan KON
      Abstract: In this study, CO2and SO2emission reductions and fuel consumption were examined for double-glazed windows that have optimum air layer thickness compared to single glazed windows in different degree-days. CO2and SO2emissions reductions tests were performed according to the combustion equations. Coal, natural gas and fuel oil were used as fuel. Calculations were made for degree-days between 1000-6000. Life cycle cost analysis and degree-days method were used in the calculations.
      PubDate: 2016-10-13
      Issue No: Vol. 21, No. 2 (2016)
       
  • Experimental and Theoretical Investigation of Pumpkin Drying in Fluidized
           Bed Dryer

    • Authors: Mert GUR
      Abstract: Thin layer drying characteristics of pumpkin cube were experimentally investigated in a  fluidized bed dryer. Experiments were performed at three different drying temperatures: 50, 60 and 70 °C.  Pumpkin used in the experiments had an initial moisture content of  95% wet basis (1930 % dry basis). The drying air velocities were set to 3.5 m/s to achieve fluidization. Experimental results show that large drying rates are obtained in the fluidized bed dryer, which are much higher than those obtained with conventional methods and convective tray dryer. In just 120 minutes moisture contents lower than 6% wet basis were achieved. Pumkin drying was mathematically modeled using the Lewis, Henderson ve Pabis, Page, and logaritmic models,  all of which are semi-emperical models widely applied in the literature. Using Fick’s first law effective diffusivities were calculated and compared with those in the literature. Effective diffusion coefficients obtained in the fluidized bed dryer were up to 70% higher than the diffusion coefficients obtained in convective tray dryers. Temperature dependence of effective diffusion coefficients was described by an Arrhenius-type relationship.
      PubDate: 2016-10-13
      Issue No: Vol. 21, No. 2 (2016)
       
  • A DC~1.6 Ghz Distributed Amplifier with GaAs MESFETs

    • Authors: Bahadır HİÇDURMAZ, Cengiz ÖZZAİM
      Abstract: In this study, a DC ~ 1.6 GHz bandwidth distributed amplifier (DA) is fabricated in printed circuit board (PCB). The scattering (S-) parameters of the distributed amplifier are measured and compared with simulated results. In characterization of the amplifier, small-signal microwave S-parameters given at some discrete frequencies of transistors are utilized. According to obtained results, it is observed that measured and simulated results are in relatively good agreement.
      PubDate: 2016-10-13
      Issue No: Vol. 21, No. 2 (2016)
       
  • Measurement of Electromagnetic Shielding Effectiveness of Woven Fabrics
           Containing Metallic Yarns by Mobile Devices

    • Authors: Erhan Kenan ÇEVEN, Ömer Faruk KARAMAN, Ahmet Emir DIRIK
      Abstract: In this study, we introduce an alternative method to evaluate the electromagnetic shielding effectiveness (EMSE) of woven fabrics containing metal wires. For experimental measurements, hybrid silk viscose yarns containing metal wires were first produced. Conductive test fabrics were then produced using the hybrid weft yarns and polyester warp yarns. The produced fabrics were separated in two parts and laminated together after rotating one fabric by 90 degrees to create a grid structure. The laminated fabrics were then folded by several times to create multiple layers such as 2,4,8,12,16. The EMSE of the multiple layered fabrics was measured over GSM signals received by a mobile device. For EMSE evaluation, the mobile device was placed between the laminated fabrics. The EMSE values of the fabrics were then calculated in accordance with the power variations of GSM signals.
      PubDate: 2016-10-09
      Issue No: Vol. 21, No. 2 (2016)
       
  • An Investigation of Antibacterial and Surface Properties of the Germanium
           Nano Layer Deposited on Organic Substrates

    • Authors: Zerrin PAT
      Abstract: The element germanium is an important material for the solid state device fabrication and antibacterial applications. It has been widely used for the optoelectronic applications. Polyethylene terephthalate (PET) materials is a organic substrate materials with high transparency. It is used to in flexible and bendable electronic device in present and future. In this study, antibacterial and surface properties of the germanium layer deposition with nano thicknesses were investigated. Germanium material was successfully deposited on PET substrate and antibacterial properties against to gram positive  Staphylococcus aureus (ATCC29213)  and gram negative Escherichia coli (ATCC11775) bacterias were tested. Germanium layer thicknesses was measured as 200 nm and grain size was calculated about 40 nm. Crystal formations of the deposited layer were determined as  (022), (133) and (224) formation. According to to XRD and EDX analysis, it found that deposited germanium layer was not contain any impurity and  chemical bonds to atoms of PET substrate. Moreover, surface analysis of deposited PET sample were realized by scanning electron microscopy and atomic force microscopy. Furthermore, surface roughness, rain height distribution, contact angle, transparency and absorbance values were determined in this paper.
      PubDate: 2016-08-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • Microwave Energy-Assisted Fabrication of Hierarchically Structured Carbon
           Nanotube/Carbon Fiber Composites

    • Authors: Selçuk POYRAZ
      Abstract: Through a facile, simple, yet efficient, affordable and ultrafast (30 s) microwave (MW) energy heating process, hierarchical composites made up of carbon fibers (CFs) decorated with multi-walled carbon nanotube (MWCNT) forest were produced at ambient conditions in one-step. Morphological features of the as-produced composites were characterized in details by using scanning and transmission electron microscopy (SEM, TEM) and the elemental analysis (EDX) techniques. Both the composite material characterization results and the versatile and easily controllable nature of the above mentioned process strongly support its promising success for the fabrication of such hierarchical composites that could be effectively used for the next generation advanced engineering applications.
      PubDate: 2016-08-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • The Evaluation of Physical Space Quality in Education Buildings in Regard
           to User Satisfaction

    • Authors: Filiz ŞENKAL SEZER, Tülin VURAL ARSLAN
      Abstract: In this study, physical space quality of two different engineering department buildings in Uludag University Gorukle Campus, Bursa, Turkey are analyzed in regard to user evaluations about the physical space quality. In the analysis of these evaluations, criteria about physical space quality are predetermined by the authors. In the method of the study, the below phases are implemented. In first, the literature review about the physical space quality is done and then a questionnaire is prepared with regard to the key themes in literature review in order to evaluate the user satisfaction. The  key themes in user satisfaction questionnaire is accessibility, ergonomics, thermal comfort, audible comfort, visual comfort, inner space air quality, service spaces, socialization. The aim of this study is first to understand which criteria are important for the students and then to improve the physical space quality in regard to the dissatisfaction.
      PubDate: 2016-08-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • The Demolition of a Reinforced Concrete Building by Using Explosives and
           Examination of It’s Efficiency

    • Authors: Meriç Can ÖZYURT, Ümit ÖZER, Abdulkadir KARADOĞAN, Ülkü KALAYCI
      Abstract: Within the scope of urban transformation new demolition techniques are seeked due to the old and damaged buildings to be demolished. Considering the advantages, controlled structure destruction by explosives is a remarkable technique that is applied successfully in abroad countries for years.In this study, the controlled demolition of Edirne Kapıkule Customs Building by using explosives was done. For this purpose, the building plan is determined by using tape measure and modelled in PC. Building’s material properties are found as a result of laboratory studies and information about building’s static balance is obtained. To determine charge, trial blasting on columns are done. From these results appropriate firing sequence is determined. The determined firing sequence is performed on the model, generated by using a finite element analyzing software. The behavior of the building, loads on columns during the demolition, are determined. The loads on columns are compared with the column’s carrying capacity. As a result of this, the deformation of the building after demolition is over, is foreseen. After the operation, it could be said that demolition achieved its goal. But the predicted deformation didn’t occur on the structure elements, explosives weren’t placed in. The reasons for this were examined.When the comparison of demolition by using machine cost and demolition by using explosives cost, the demolition by using machine is more advantageous because of less number of floors. It ıs observed that, measured vibration values  are not adequate  to cause damage on reinforced concrete buildings.
      PubDate: 2016-08-29
      Issue No: Vol. 21, No. 2 (2016)
       
  • Production of CdTe Semiconductor Thin Films by Electrodeposition Technique
           for Solar Cell Applications

    • Authors: Ahmet PEKSÖZ
      Abstract: Electro-deposited cadmium tellurite (CuTe) thin film was grown onto ITO-coated glass substrate for 120 seconds at the room temperature and a constant cathodic potential of -0.85 V. Deposition solution was prepared from cadmium chloride (CdCl2), sodium tellurite (Na2TeO3) and pure water. The pH value of the deposition solution was adjusted to 2.0 by adding HCl. The EDX analysis shows that the film has 52% Cd and 48% Te elemental compositions. Film thickness was found to be 140 nm. The CdTe thin film exhibits p-type semiconductor character, and has an energy bandgap of 1.47 eV. 
      PubDate: 2016-08-27
      Issue No: Vol. 21, No. 2 (2016)
       
  • Water Quality of Emet Stream Basin

    • Authors: Cem TOKATLI, Esengül KÖSE, Naime ARSLAN, Özgür EMİROĞLU, Arzu ÇİÇEK, Hayri DAYIOĞLU
      Abstract: Emet Stream Basin is one of Turkey's most important river systems and one of the two most important branches of Uluabat Lake (Ramsar Area). The system is under an intensive pressure of agricultural and industrial activities and domestic wastes. In this study, water samples were collected seasonally from eight stations (one of them is on the Kınık Stream, one of them is on the Dursunbey Stream and six of them on the Emet Stream) on the Emet Stream Basin. Some lymnological parameters (nitrate nitrogen, nitrite nitrogen, ammonium nitrogen, sulfate, orthophosphate, and BOD5) were determined to evaluate the water quality. The data obtained were evaluated statistically and compared with the limit values reported by various national and international organizations. It was determined that, Emet Stream Basin is exposed to a significant organic pollution. 
      PubDate: 2016-08-27
      Issue No: Vol. 21, No. 2 (2016)
       
  • Climatic Chamber with Chassis Dynamometer Testing Simulator Car Model
           Development and Validation Process

    • Authors: Hüseyin BAYRAM
      Abstract: Military and commercial vehicles are subjected to many tests, in the R & D stage before serial production. During this test process, critical parts have  to be improved according to the evaluation of vehicle's performance. Measurement of several parameters and  simulation of real life conditions are essential for correct interpretation of the test results. There are specially developed simulators to provide the required test conditions. These systems are simulating real life conditions (temperature, humidity, load, force, etc.) and provide a suitable environment for test process. Simulators accelerate the testing process and saving  considerable amount of time. Climatic chamber with integrated chassis dynamometer is used to  accelerate the process of design verification. Climatic chamber  can  provide  different environmental conditions and by this way test processes can be performed independent from the ambient conditions.Moreover  the chassis dynamometer provides testing the vehicle’s power pack and chassis components ınstead of testing the vehicle in road conditions . In this article, a testing laboratory, which was built by integrating the climatic chamber and chassis dynamometer, has been focused on. Firstly the operating principles of the climatic chamber and the chassis dynamometer has been explained  and then the simulators’ characteristics are indicated. Secondly the main parameters for  the simulation of the resistance acting on the vehicle  during road tests have been  calculated with the coast-down test on the dynamometer. Finally the same test was performed both on the road and on the simulator  for comparing the test results.
      PubDate: 2016-01-12
      Issue No: Vol. 21, No. 2 (2016)
       
  • Design of an Ann Model Trained by Various Learning Algorithms to Compute
           the Operating Frequency of E-Shaped Patch Antennas

    • Authors: Ahmet KAYABAŞI, Abdurrahim TOKTAŞ, Ali AKDAĞLI
      Abstract: An artificial neural network (ANN) trained by different learning algorithms implemented to computing the operating frequency of E-shaped patch antennas (EPAs) is designed in this study. The ANN model is built on a multilayered perceptron (MLP) based on feed forward back propagation (FFBP). A data pool is firstly constituted for training and testing the ANN model through 144 EPA simulations using the moment method-based HyperLynx® 3D EM software in terms of the operating frequency. The ANN model is then trained via 130 data, and the accuracy of the model is tested through 14 data of simulated EPAs. The ANN is trained by 8 different learning algorithms to achieve a robust model. A benchmark which compares the learning algorithms against each other according to percentage error is revealed. The validity of the ANN is corroborated by simulated and measured data reported in the literature. It shows that the ANN model trained by Levenberg–Marquardt learning algorithm computes the closest results. The proposed ANN model can be successfully exploited to analyze the EPAs in views of the operating frequency.
      PubDate: 2016-01-12
      Issue No: Vol. 21, No. 2 (2016)
       
  • A 0-1 Integer Programming Model for the Course Scheduling Problem and A
           Case Study

    • Authors: Hakan ALTUNAY, Tamer EREN
      Abstract: The course scheduling problem is one of the most common timetabling problems which are frequently encountered in all educational institutions, especially universities. This problem which is getting harder to solve day by day, means the assignment of the lessons and lecturers into the most suitable timeslots and classrooms, provided that various constraints are taken into account. These constraints peculiar to the problem are consisted due to various factors such as the characteristics and the rules of the educational institutions, preferences of lecturers, students’ requests and suggestions. In this study, a novel 0-1 integer programming model that considers preferences of lecturers is proposed for the course scheduling problem. The proposed mathematical model is also tested with a case study from Uludag University. Thus, the performance of the mathematical model can be tested and the results can be analyzed. The results of the carried out application show efficient results in preparing a course schedule that meets the preferences of the lecturers and complies with the rules of the institutions.
      PubDate: 2016-01-12
      Issue No: Vol. 21, No. 2 (2016)
       
  • An Analysis on Turkey’s First Tram Silkworm
           (İpekböceği) Line

    • Authors: Kerem Oğuz ŞİMİT, Mehmet RİZELİOĞLU, Turan ARSLAN
      Abstract: The role of tramways as an alternative public transportation system has been increasing in urban transportation system.  Although, the use of tramway is not at desired level compared to the use of rubber-tired based public transportation modes in Turkey, the SilkWorm (İpekböceği), being the first domestic tram produced in Turkey, will have a great impact on Turkey rail public transportation system.  However, some arguments have arisen over its first operation on T1 tram line in Bursa which was built in the end of 2013. Though, it is relatively very new one, some problems have already been observed on this line. The available data are not enough yet to do some analysis, therefore only a simple SWOT analysis is carried out to define the problems that appeared after its operation on the line and to put forward some possible solutions for them.
      PubDate: 2016-01-12
      Issue No: Vol. 21, No. 2 (2016)
       
  • Investigation of Limit States Specified for Reinforced Concrete Column
           Members in TEC–2007

    • Authors: Umut HASGÜL, Altuğ YAVAŞ, Kaan TÜRKER, Mehmet TERZİ, Tamer BİROL
      Abstract: In this study, the deformation based limit states stipulated for reinforced concrete members in the Turkish Earthquake Code (TEC) were experimentally investigated. Thus four RC cantilever columns which have low concrete compressive strengths and have not adequate confinement, were subjected to constant axial load and cyclic lateral load history. In the study, firstly, the strain values representing the damage limits were converted to top of the column lateral displacements by using fundamentals of structural mechanics. Subsequently the column damages corresponding to the displacement demands were observed, hence limit states were evaluated. After conducting all column tests, it was noted that no column damage was observed for the immediate occupancy (IO) performance level defined in the code. For the life safety (LS) and collapse prevention (CP) performance levels, though somewhat residual deformations occurred on the critical regions, the column members can pretty much sustain their lateral load capacities. It was also observed for all columns that significant damages and strength losses occurred beyond the collapse prevention level. The results of experimental study indicate that the evaluation procedure in the TEC is still in good relationship with the limit states even if the columns have not adequate compressive strength and confinement.
      PubDate: 2016-01-12
      Issue No: Vol. 21, No. 2 (2016)
       
 
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