Yazarlar
- Peker, Iskender(23)
- Araz, Onur(16)
- Erol, Ismail(15)
- Ar, Ilker Murat(12)
- Bayraktar, Alemdar(10)
- Seferoğlu, Mehmet Tevfik(10)
- Aydin, Metin Mutlu(9)
- Günaydin, Murat(9)
- Adanur, Süleyman(8)
- Altunişik, Ahmet Can(8)
- Basoglu, Mustafa Engin(8)
- Akyol, Mehmet(7)
- Yanarateş, Cağfer(7)
- Akpinar, Muhammet Vefa(6)
- Altan, Aytaç(6)
- Barut, Abdulkadir(6)
- Başoğlu, Mustafa Engin(6)
- Cakmak, Recep(6)
- Searcy, Cory(6)
- Çavdar, Özlem(6)
- Baki, Birdogan(5)
- Benli, Tolga(5)
- Gergin, Ramazan Eyüp(5)
- Kahya, Volkan(5)
- Kuzulugil, Kenan(5)
- Ozden, Talat(5)
- Pala, Fahrettin(5)
- Seferoğlu, Ayşegül Güneş(5)
- Sevim, Bariş(5)
- Yilmaz, Tekin(5)
- Adanur, S.(4)
- Adanur, Suleyman(4)
- Aksüt, Yavuz Selim(4)
- Altunisik, Ahmet Can(4)
- Aydin, Musa(4)
- Cakir, Mehmet Ali(4)
- Cavusoglu, Ibrahim(4)
- Coruh, Emine(4)
- Ercikdi, Bayram(4)
- Gunaydin, M.(4)
Yayınlar
- MakaleYalnız künye2015Utilization of granulated marble wastes and waste bricks as mineral admixture in cemented paste backfill of sulphide-rich tailings
Ercikdi, Bayram; Külekci, Gökhan; Yilmaz, Tekin
This study presents the utilisation of granulated marble wastes (MW) as an additive (10-30 wt%) and waste bricks (WB) as replacement and additive (15-45 wt%) to ordinary Portland cement (OPC) for cemented paste backfill (CPB) of sulphide tailings. OPC was used as binder at 7 wt% dosage. Pozzolanic activity tests showed that the fineness of the WB samples, not the chemical composition, is the major factor affecting their pozzolanic activity. Although they do not exhibit any pozzolanic activity, the use of MW samples as an additive to OPC improves acid buffering capacity of CPB samples and enhances their short and long-term mechanical performance. The UCSs of CPB samples increased with increasing additive rates and decreased with increasing replacement ratios. All CPB samples produced the desired strength and durability when MW and WB were used as an additive to OPC. However, a binder dosage of >7 wt% was required to produce the desired 28-day strength of ≥0.7 MPa when the OPC was replaced by 15-45 wt% WB samples. The durability (i.e. no loss of strength) of CPB samples is closely inter-related with the calcination temperatures and glass phase content of WB.
- MakaleAçık Erişim2015Prediction of pedal cyclists and pedestrian fatalities from total monthly accidents and registered private car numbers
Ghasemlou, Kiarash; Aydin, Metin Mutlu; Yildirim, Mehmet Sinan
Accident prevention is relatively a complex issue considering the effectiveness of the injury prevention technologies as well as more detailed assessment of the complex interactions between the road condition, vehicle and human factor. For many years, highway agencies and vehicle manufacturers showed great efforts to reduce the injuries resulting from the vehicle crashes. Many researchers used a broad range of methods to evaluate the impact of several factors on traffic accidents and injuries. Recent developments lead up to capable for determining the effects of these factors. According to World Health Organization (WHO), cyclists and pedestrians comprise respectively 1.6% and 16.3% in traffic crash fatalities in 2013. Also in Turkey crash fatalities for pedestrian and cyclists are respectively 20.6% and 3% according to Turkish Statistical Institute data in 2013. The relationship between cycling and pedestrian rates and injury rates over time is also unknown. This paper aims to predict the crash severity with the traffic injury data of the Konya City in Turkey by implementing the Artificial Neural Networks (ANN), Regression Trees (RT) and Multiple Linear Regression modelling (MLRM) method.
- BildiriAçık Erişim2015Convergence in local press
Tingoy, Ozhan; Isikli, Sevki; Gumushane, Ali Ozcan
Improvements in information and communication technologies have evolved the way of traditional broadcasting. This evolvement is currently being experienced in press, eliminating the specific and clear lines of every kind of medium. Changing news production/distribution process as well as readers' consumption tendencies have brought up some kind of negative presumptions related with the future of press. Taken into consideration on the level of widespread newspapers, this evolvement is siginificant in respect of the future of local newspapers which count around 1400 in Turkey, trying to survive financial reasons. Fullfilling the evolvement triggered by information and communication technologies successfully, local newspapers are now expected to fulfill their alternative journalism mission against global media contents with the help of new media environment.
- MakaleAçık Erişim2014Structural Analysis of Forest Product Businesses in GumushaneProvince
Top, Yener; Adanur, Hakan; Öz, Mehmet; Yasar, Mehmet
In total, 95% of all business enterprises established in Turkey are micro-scale, and this figure increases to 98.6% in the forest products industry. Micro-scale enterprises are important in terms of production, employment, and overcoming economic imbalances among regions. The forest products industry, which includes three subdivisions within the manufacturing sector, occupies an important place in the overall Turkish manufacturing sector. Thus, this study examined the structural characteristics of forest product enterprises in Gumushane Province. The research involved in-person interviews with personnel at 47 enterprises. The data revealed that the sawmill division was especially important with respect to the use of local poplar logs. The sawmill and furniture divisions accounted for 28% of all enterprises and 26% of all employees in the manufacturing sector in Gumushane. We found that 57% of enterprises had difficulty in finding working capital and 55% of enterprises experienced shortages of labour. The average contribution of each forest products business to employment (2.55) was more than that of other manufacturers in Gumushane (2.27). The forest product businesses in Gumushane resemble other micro-scale enterprises located in other regions of Turkey in terms of their structural properties.
- MakaleYalnız künye2014Strength and ultrasonic properties of cemented paste backfill
Ercikdi, Bayram; Yilmaz, Tekin; Külekci, Gökhan
This paper presents the strength (UCS) and ultrasonic pulse velocity (UPV) properties of cemented paste backfill (CPB) produced from two different mill tailings (Tailings T1 and T2). A total of 240 CPB samples with diameter × height of 5 × 10 cm and 10 × 20 cm prepared at different binder dosages (5-7 wt.%) and water-to-cement ratios (3.97-5.10) were subjected to the UPV and UCS tests at 7, 14, 28 and 56-days of curing periods. UCS and UPV of CPB samples increased with increasing the binder dosage and reducing the w/c ratio irrespective of the sample size and tailings type. CPB samples with a diameter × height of 5 × 10 cm were observed to produce consistently higher (up to 1.69-fold) UCSs than those of 10 × 20 cm CPB samples at all binder dosages and w/c ratios. However, at the corresponding binder dosages and w/c ratios, the maximum variation of UPV between the CPB samples of 5 × 10 cm and 10 × 20 cm was only 7.45%. Using the method of least squares regression, the UCS values were correlated with the UPV values for CPB samples of 10 × 20 cm in size. A linear relation with a high correlation coefficient appeared to exist between the UCS and UPV for CPB samples. These findings suggest that the UPV is essentially independent of the sample size. In this regard, the UPV test can be suitably exploited for the rapid estimation of the strength and quality of CPB samples even using small samples with concomitant benefits of reducing sample size.
- MakaleYalnız künye2014Assessment of strength properties of cemented paste backfill by ultrasonic pulse velocity test
Yilmaz, Tekin; Ercikdi, Bayram; Karaman, Kadir; Külekçi, Gökhan
Ultrasonic pulse velocity (UPV) test is one of the most popular non-destructive techniques used in the assessment of the mechanical properties of concrete or rock materials. In this study, the effects of binder type/dosage, water to cement ratio (w/c) and fines content (<20 μm) of the tailings on ultrasonic pulse velocity (UPV) of cemented paste backfill (CPB) samples were investigated and correlated with the corresponding unconfined compressive strength (UCS) data. A total of 96 CPB samples prepared at different mixture properties were subjected to the UPV and UCS tests at 7, 14, 28 and 56-days of curing periods. UPV and UCS of CPB samples of ordinary Portland cement (CEM I 42.5 R) and sulphate resistant cement (SRC 32.5) initially increased rapidly, but, slowed down after 14 days. However, UPV and UCS of CPB samples of the blast furnace slag cement (CEM III/A 42.5 N) steadily increased between 7 and 56 days. Increasing binder dosage or reducing w/c ratio and fines content (<20 μm) increased the UCS and UPV of CPB samples. UPV was found to be particularly sensitive to fines content. UCS data were correlated with the corresponding UPV data. A linear relation appeared to exist between the UCS and UPV of CPB samples. These findings have demonstrated that the UPV test can be reliably used for the estimation of the strength of CPB samples.
- BildiriYalnız künye2014Imaging of the deteriorations and concrete quality of the tunnels (Zigina, Torul) with ground penetrating radar
Saricicek, Isil; Seren, Aysel; Lambot, S.; Giannopoulos, A.; Pajewski, L.; Andre, F.; Slob, E.; Craeye, C.
Ground Penetrating Radar (GPR) that give high resolution image and no damage to the researched surface, holds an important place in the use of near surface shallow researches. In this study; it is aim to investigate the fracture-crack system, the stratigraphy and the deterioration of the walls of Zigana Tunnel which is located at the way Trabzon-Gümüşhane in order to evaluate the existence of risk area leaking water out and structure contents. Furthermore, in addition to Zigana tunnel, the concrete quality of the Torul tunnel which has built recently was investigated. During examinations, GPR data were collected along totally 20 profiles at the entrance of the both sides of tunnels by using 500 MHz and 800 MHz shielded antennas. After applying data processing stages to the collected data, 2D and 3D images were acquired and interpreted.
- BildiriYalnız künye2014Pid controlled line follower robot design on indoor 3D networks
Kose, Oguz; Karas, Ismail Rakip
Robots are commonly used and developed for different purposes in various areas such as research, educational, commercial, and industrial fields, also in emergency situations and space missions in today’s modern world. Robots are the machines that increasingly gain the importance with each passing day by the development of micro-electronics and micro-mechanics industry. To define a machine as a robot, it needs to have the sensors to check its environment; the mechanisms to evaluate the information received from these sensors and to transfer to the processing units. In this study, an intelligent controlled line follower robot was developed. Proportional-integral-derivative (PID) method was used for controlling. According to the information from the sensors, the method applied to the engines as Pulse Width Modulation (PWM). Online Fez Panda II embedded system board was used as the control element. This board has a 2-bit ARM 7 (Acorn RISC Machine) processor and it is suitable to.Net Micro Framework Technology. The system software was written with C# programming language in Visual Studio 2010 platform. The robot was tested on 3D indoor network, and has potential to be used for evacuation process on extraordinary sitautions in buildings. Another usage areas of this robot are factories and production lines. 3D network analyses and navigation applications could also be performed using the lines on the ground of this kind of environment.
- MakaleYalnız künye2014Determination of structural behavior of Bosporus suspension bridge considering construction stages and different soil conditions
Günaydin, Murat; Adanur, Süleyman; Altunişik, Ahmet Can; Sevim, Bariş; Türker, Emel
In this paper, it is aimed to determine the structural behavior of suspension bridges considering construction stages and different soil conditions. Bosporus Suspension Bridge connecting the Europe and Asia in Istanbul is selected as an example. Finite element model of the bridge is constituted using SAP2000 program considering existing drawings. Geometric nonlinearities are taken into consideration in the analysis using P-Delta large displacement criterion. The time dependent material strength of steel and concrete and geometric variations is included in the analysis. Time dependent material properties are considered as compressive strength, aging, shrinkage and creep for concrete, and relaxation for steel. To emphases the soil condition effect on the structural behavior of suspension bridges, each of hard, medium and soft soils are considered in the analysis. The structural behavior of the bridge at different construction stages and different soil conditions has been examined. Two different finite element analyses with and without construction stages are carried out and results are compared with each other. At the end of the analyses, variation of the displacement and internal forces such as bending moment, axial forces and shear forces for bridge deck and towers are given in detail. Also, displacement and stresses for bridge foundation are given with detail. It can be seen from the analyses that there are some differences between both analyses (with and without construction stages) and the results obtained from the construction stages are bigger. It can be stated that the analysis without construction stages cannot give the reliable solutions. In addition, soil condition have effect on the structural behavior of the bridge. So, it is thought that construction stage analysis using time dependent material properties, geometric nonlinearity and soil conditions effects should be considered in order to obtain more realistic structural behavior of suspension bridges.
- MakaleYalnız künye2013The contribution of hydropower in meeting electric energy needs: The case of Turkey
Akpinar, Adem
In this article, an attempt is made to better understand the contribution of hydropower in meeting electric energy needs of Turkey. Thus, a comparison between Turkey and other countries, which have some similarities with Turkey or which are more developed nations compared to Turkey, for evaluating from different aspects the contribution of hydropower in meeting electric energy needs is performed. The producers of electricity and hydroelectricity in the world, and the electric sectors of all the selected countries are firstly examined. Thereafter, Turkey's water resources and its potential, hydropower potential, and current status of hydropower in Turkey are investigated in detail. A detailed discussion regarding economic and energy indicators, hydroelectricity versus thermal electricity, the contributions of hydroelectricity to the total and renewable electricity generation, and the usage status of hydro potential of each selected nation is also made. Finally, it is found that hydropower is the second largest contributor in meeting Turkey's electric energy needs after thermal, mainly natural gas. It is also estimated that the contribution of hydropower will continue because a vast amount of its economically feasible hydro potential (about 64%) is undeveloped. Besides, it is determined that the contribution of hydropower in the total electricity generation in Turkey is greater than that of China and India, but it is lower than that of Norway, Brazil, and Canada.
- MakaleAçık Erişim2013Simulation of a large electric distribution system having intensive harmonics in the industrial zone of Konya
Eroǧlu, Hasan; Aydin, Musa
In this study, measurements were taken at difierent points of a sample distribution system in order to analyze the levels of harmonics that appear as a day-to-day increasing problem in electrical distribution systems. According to the measurement values, the dominant harmonics have been determined and an electrical model of the system has been prepared using the SimPowerSystems toolbox from MATLAB and Simulink. The accuracy of the electrical model has been verified by the measurement and simulation values. In addition, the transformer connection types' and impedances' simulations have been presented to understand and solve the harmonic problems in electrical distribution systems. With the help of this study, advanced analysis can be performed in the electrical distribution system for power quality analyses and this study can be a background for similar kinds of simulation studies.
- BildiriYalnız künye2013Genetic algorithm in Electrical Transmission Lines path finding problems
Eroglu, Hasan; Aydin, Musa
Today, Geographic Information Systems (GIS) solutions have entered every corner of the engineering studies like Electrical Transmission Lines (ETL) route optimization, vehicle routing, power plant siting and so on. Raster-based maps generated by GIS are very useful solutions for this kind of route optimization problems. The weighted sum of all the data can be converted to raster-based maps and gathered consecutively in GIS for ETL route optimization. In this paper, Genetic Algorithm (GA) is applied to ETL route optimization problems in order to find the best route on raster-based maps.
- MakaleYalnız künye2012Estimation of Elasticity Modulus of a Prototype Arch Dam Using Experimental Methods
Sevim, Baris; Altunisik, Ahmet Can; Bayraktar, Alemdar; Akköse, Mehmet; Adanur, Suleyman
Using experimental methods, this study presents the estimation of the dynamic and static ( secant) elasticity modules of a prototype arch dam. These experimental methods are ambient vibration tests, uniaxial compression tests, and ultrasonic velocity tests. Implementation of the methods on a prototypical arch dam-reservoir-foundation model of the dam, constructed under laboratory conditions, allows estimation of the elasticity modules. Random impact loads excite the arch dam during ambient vibration testing, which creates response signals for measurement. Commercially available software transfers the signals, and processing those signals allows estimation of the experimental natural frequencies of the arch dam. Analysis of a three-dimensional (3D) finite element model (FEM) of the arch dam determines natural frequencies. The estimation of the elasticity modules of the arch dam arises from a comparison of the experimental and analytical frequencies. The uniaxial compression tests use several specimens of the fresh and hardened concrete of the prototype model, and those tests provide the compressive strengths and stress-strain relationships. The ultrasonic velocity tests apply several velocity measurements to the arch dam and foundation, resulting in estimation of the elasticity modulus from empirical equations related to concrete mix design, compressive strength, and velocity values. This study discusses the difficulties of the determination of the elasticity modulus and suggests that ambient vibration testing and the finite element method are useful for overcoming these difficulties. DOI: 10.1061/(ASCE)MT.1943-5533.0000361. (C) 2012 American Society of Civil Engineers.
- Derleme MakaleYalnız künye2012RETRACTED: Regional sustainable water and energy development projects: A case of Southeastern Anatolia Project (GAP) in Turkey (Retracted article. See vol. 83, pg. 173, 2018)
Akpinar, A.; Kaygusuz, K.
Southeastern Anatolia Project (GAP) region in Turkey is rich in water for irrigation and hydroelectric power. The Euphrates and Tigris Rivers represent over 28% of the nation's water supply by rivers, and the economically irrigable areas in the region make up 20% of those for the entry country. Turkey has a total gross hydropower potential of 433 GWh/yr, but only 125 GWh/yr of the total hydroelectric potential of Turkey can be economically used. By the construction of new hydropower plants, 36% of the economically usable potential of the country would be tapped. The GAP region has a 22% share of the country's total hydroelectric potential, with plans for 22 dams and 19 hydroelectric power plants. Once completed, 27 billion kWh of electricity will be generated annually. (C) 2011 Elsevier Ltd. All rights reserved.
- MakaleYalnız künye2012The total electricity energy production of the world, European Union, and Turkey: Projections and comparison
Akpinar, A.; Tavşan, F.; Kömürcü, Murat Ihsan; Filiz, M.H.; Kaygusuz, K.
This study aims to forecast the world's, European Union's (EU), and Turkey's electricity energy generation until 2030. For this purpose, the electricity energy sector of the world, EU, and Turkey was overviewed from past to present. The total electricity energy generation for the world, EU, and Turkey were then modelled by using historical energy generation data as years with regression analysis. Data from 1970 to 2004 for Turkey and data from 1980 to 2004 for the world and EU were used for the projections. Electricity energy productions have been forecasted up to year 2030. According to the results, it is determined that cubic (R2 = 0.997) and linear (R2 = 0.993) models for projection of the world's and EU's electricity energy generation, respectively, is fitness while the quadratic (R2 = 0.996) model fits for the projection of Turkey's total electricity energy generation and Turkey will have 0.995% of the world's electricity energy generation in 2030, while the EU will have 8.41% within the world's electricity energy generation in 2030 if the current trend continues.
- BildiriYalnız künye2012Designing a load agent for power management with a multi-agent home automation system
Özden, Talat; Okumuş, Halil Ibrahim
In this study, a load agent design is performed for the power management which lets us use existing electrical energy for consumer's needs, comfort and criteria in the areas such as flats and commercial buildings that independently meet their energy need from renewable energy sources. The load agent is designed on the basis of radio-frequency communication so it is a wireless communication system which also has the ability of switching off or making power flow by measuring current of the load. The agent has a flexible structure in order to be compatible with all ambient equipments. It can work with all equipments on the system properly, without any hardware changing. And this is shown in the paper.
- Derleme MakaleYalnız künye2012Hydropower for sustainable energy development in Turkey: The small hydropower case of the Eastern Black Sea Region
Capik, Mehmet; Osman Ylmaz, Ali; Cavusoglu, Ibrahim
Turkey is a rich country from the point of variety and potential of renewable energy resources. Hydros, winds, biomass, solar and geothermal are important renewable and environmentally friendly sources for energy in Turkey. Turkey produces large amount of hydropower with a total gross hydropower potential of 433 TW h/yr, which is equal to 13.8% of the total hydropower potential of Europe. Technically useable potential is 216 TW h/yr and economic potential is 140 TW h/yr. The main aim of the present study is to investigate hydropower potential of Turkey and small hydropower plants in Eastern Black Sea Region for sustainable energy development in Turkey. The geography of Turkey especially, Eastern Black Sea Region supports and suitable the development of the small hydro plants to increase the energy generation and utilization of available water sources in Turkey. Besides, the paper deals with hydropower policies to meet ever increasing energy demand for sustainable development of Turkey.
- MakaleAçık Erişim2012Construction stage analysis of Humber Suspension Bridge
Adanur, Süleyman; Günaydin, Murat; Altunişik, Ahmet Can; Sevim, Bariş
Suspension bridges are widely used as engineering structures to across long spans and give rise to the usage of domains under the bridge. In the finite element analyses of suspension bridges, it is assumed that the structure is built and loaded in a second. However, this type of analysis does not always give the reliable and healthy solutions. Because, construction period of this type of the structures continue along time and loads may be changed during this period. Therefore, construction stages and time dependent material properties should be considered in the analysis to obtain the reliable and healthy results. This paper presents the construction stage analysis of suspension bridges using time dependent material properties. For this purpose, Humber Suspension Bridge built near Kingston upon Hull, England is chosen as an example. Finite element model of the bridge is constituted using SAP2000 program considering project drawings. Geometric nonlinearities are taken into consideration in the analysis using P-Delta large displacement criterion. The time dependent material strength of steel and concrete and geometric variations are included in the analysis. Time dependent material properties are considered as compressive strength, aging, shrinkage and creep for concrete, and relaxation for steel. The structural response of the bridge at different construction stages has been examined. Two different finite element analyses with and without construction stages are carried out and results are compared with each other. As analyses result, variation of the displacement and internal forces such as bending moment, axial forces and shear forces for bridge deck and towers are given with detail. It can be seen from the study that there are some differences between both analyses (with and without construction stages) and the results obtained from the construction stages are bigger. So, it is thought that construction stage analysis using time dependent material properties and geometric nonlinearity should be considered in order to obtain more realistic structural response of suspension bridges.
- BildiriYalnız künye2012Modeling of FLC-incremental based MPPT using DC-DC boost converter for standalone PV system
Cakmak, Recep; Altas, Ismail H.; Sharaf, Adel M.
This paper presents the modeling of a Fuzzy Logic Controller-Incremental (FLC-Inc.) based maximum power point tracking (MPPT) method and its comparison with traditional Perturb and Observation (P&O) method for standalone photovoltaic (PV) systems. The PV system, which is composed of PV panels, boost converter, MPPT unit and dc load, is modeled and digitally simulated in MATLAB/Simulink. The simulated results are illustrated to show the improvements obtained by the proposed FLC-Inc. based MPPT method.
- Derleme MakaleYalnız künye2012Present situation and potential role of renewable energy in Turkey
Çapik, Mehmet; Yilmaz, Ali Osman; Çavuşoĝlu, Ibrahim
Turkey has a rich potential of hydropower, wind and geothermal energy resources. The distribution of these renewable energy sources in operation are hydropower, wind and geothermal 14.802 MW 1002MW and 94 MW, respectively. Turkey possesses a huge hydroelectric resource which is one of the Turkey's major energy assets. Most of the important uses of water in power plants have been developed in the electricity generation. Turkey has a total gross hydropower potential of 433 TWh/yr, which is equal to 13.8% of the total hydropower potential of European. Technically useable and economic potential are 216 TWh/yr and 140 TWh/yr, respectively. The total share of all energy for electricity power generation in 2010 are coal, natural gas, fuel oil and renewable energy, 104,040 GWh, 125,549 GWh, 18,215 GWh, and 86,120 GWh respectively. Among the renewable energy resources in Turkey, biomass and solar energy are also important because their share in total energy consumptions have increased. On the other hand, Turkey has not utilized nuclear energy yet. The current government plans to have a nuclear power plant with a capacity of 1800MW at the Black Sea Port of Sinop. The main purpose of the energy policies is to answer the energy needs of increasing population and growing economy at minimum costs while making energy supply planning. Turkey's specific national energy strategy document and energy policy objectives are outlined in the institutional strategic plans. These strategic plans are energy supply security, regional and global influence in the area of energy and environment protection. The aim of energy policy including renewable are to develop existing energy sources and to avoid dependence on energy imports and to encourage private sector investment and to improve the reliability of electricity supply. The main aim this study will investigate at the present potential of energy resources and future contributions to the national energy consumption in Turkey. As result present energy situation, the renewable energy potential, and the energy politics of Turkey are investigated.
