Yazar "Yucel, Mehmet Ali" seçeneğine göre listele

Listeleniyor 1 - 10 / 10
  • [ X ]
    Öğe
    Areal Change Detection and 3D Modeling of Mine Lakes Using High-Resolution Unmanned Aerial Vehicle Images
    (Springer Heidelberg, 2016) Yucel, Mehmet Ali; Turan, Recep Yavuz
    This study focuses on the Etili and Comakli open-pit coal mines, where mine lakes are most densely located within the Can Coal Basin (northwestern Turkey). The aim of our study was to create 3D terrain models of these mine lakes using high-resolution images from an unmanned aerial vehicle (UAV) and to quantify areal changes linked to anthropogenic and meteorological effects over the study period. In November 2014 and October 2015, a DJI F550 hexacopter was flown at elevations of 30-100 m, and images were acquired using a 12-megapixel camera. Nineteen flights were completed, with each flight acquiring between 109 and 554 images. 3D modeling of UAV images was carried out with Agisoft software, using the most common structure from motion algorithm. Its workflow, involving image matching, georeferencing, digital elevation modeling, orthomosaics, 3D point cloud, and 3D textured model creation, was used to generate our 3D terrain model for the mine lakes. Orthomosaics with 1-6 cm/pixel resolution were used to assess areal change in the mine lakes. Area was calculated using two different methods (digitization and classification) within the ArcGIS package; results of these two methods were compared. Our UAV study of open-pit mines rapidly and precisely determined changes in topography linked to anthropogenic and meteorological effects. It also proved to be an effective method of visualizing such effects over the short term.
  • [ X ]
    Öğe
    Change detection and visualization of acid mine lakes using time series satellite image data in geographic information systems (GIS): Can (Canakkale) County, NW Turkey
    (Springer, 2014) Yucel, Deniz Sanliyuksel; Yucel, Mehmet Ali; Baba, Alper
    Can, a county in the province of Canakkale, is one of the most prominent coal mining districts in Turkey. Many mining companies have been operating coal deposits for power generation and district heating in this region since 1980. Generally, small and medium-scale mining companies operate for short periods and abandon the operational land without providing any rehabilitation. Human intervention in the natural structure and topography of the earth surface causes large holes and deterioration in these areas. Artificial lakes occur because of surface discharge and underground leakage into abandoned open pit mines with high lignite sulfur content (0.21-14.36 wt %). Furthermore, these lakes gain acidic character due to acid generation from pyrite oxidation. Acid mine lakes are highly acidic (pH < 3.05) and have elevated concentrations of , Fe and some metals. The main objective of this study is to evaluate the environmental conditions and demonstrate the development of a monitoring system for their possible changes in the acid mine lakes of the open cast lignite mining area on a regional scale. For this purpose, the data received from remote sensing satellites were used. Areal change detection and perimeter changes of nine acid mine lakes caused by coal mining companies in Can from 1977 to 2011, were determined using Landsat, Quickbird and Worldview satellite images. As a case study, an area of 9 km(2) was chosen for the variety of acid mine lakes. Using GIS software, satellite images were analyzed in time series, borders of acid mine lakes were digitized and converted into vector data format. At this stage, prior to the digitization, in order to create contrast on the satellite images, stretch type and stretch values were changed. The areal and perimeter changes were computed and presented via tables and graphics. In addition, thematic maps of the acid mine lakes were created and visualized. The results show that the number of acid mine lakes increased and these caused environmental risks due to their hydrochemical properties and areal increments.
  • [ X ]
    Öğe
    Determining hydrochemical characteristics of mine lakes from abandoned coal mines and 3D modelling of them using unmanned aerial vehicle
    (Pamukkale Univ, 2017) Yucel, Deniz Sanliyuksel; Yucel, Mehmet Ali
    This study was undertaken with the aim of creating three dimensional (3D) models of mine lakes formed in abandoned coal mines of the Can coal basin using high resolution unmanned aerial vehicle (UAV) images, determining hydrochemical characterization and investigating environmental effects. In May 2014 a DJI F550 model hexacopter was flown at heights varying from 30-100 m above lakes and surroundings and images were obtained with a 12 mega pixel camera. During the image processing stage the Agisoft program was used and orthophoto of the lakes with resolution from 1-6 cm and 3D terrain models were created. The total area of the lakes calculated from UAV images was 298751 up Additionally water samples were taken from lakes and downstream rivers simultaneous to UAV studies. According to water pollution control regulation in Turkey, the mine lakes were very severely polluted with low pH and high concentrations of metals such as Al, Fe, Mn, Ni and Zn. The lakes were in the category of water not suitable for use under any circumstances. There is a very high possibility that if these lakes drain the water resources will be affected. As a result it is necessary to rehabilitate the mine lakes as soon as possible using the most appropriate method for the field.
  • [ X ]
    Öğe
    Displacement of the South Pole from 2006 to 2021: Role of sea ice and Antarctic surface temperature
    (Masaryk University, 2022) Pirti, Atınç; Yucel, Mehmet Ali; Hoşbaş, Ramazan Gürsel
    The effect of global warming on the southern polar regions necessitates careful monitoring of glacier deformations and their movements, as well as an understanding of atmospheric physics. For this purpose, the yearly movements of UNAVCO stations-South Pole Station (AMU2) (winter-summer) and other stations in the South Pole region have been observed in this paper for about a fifteen-year period (2006–2021). In addition, the area differences of the Antarctic continent due to seasonal changes (winter-summer) between 1980 and 2021 were investigated in this study. Moreover, the height values of the stations on the Antarctic continent were observed seasonally. The subglacial lakes in the Antarctic continent cause the differences in the height values as a result of the seasonal changes. A decrease in sea ice of 0.91 million km2 for the winter season and 0.55 million km2 for the summer season during a 41-year period has been determined for four sectors of the Antarctic continent. The temperature changes on the Antarctic continent in the summer and winter seasons (2005–2022) were also evaluated in this paper. Air temperature increases was apparent especially in the Antarctic Peninsula, East Antarctic and West Antarctic coasts. The Weddell Sea and the Amundsen Sea regions have had the most sea ice loss, each with 1.24 million km2. On the other hand, it can be observed that the East Antarctic sector has expanded by 0.32 million km2 © 2022 EMUNI Press. All rights reserved.
  • [ X ]
    Öğe
    Geophysical investigations at Agadere Cemetery, Gallipoli Peninsular, NW Turkey
    (Taylor & Francis Ltd, 2014) Buyuksarac, Aydin; Yalciner, Cahit Caglar; Ekinci, Yunus Levent; Demirci, Alper; Yucel, Mehmet Ali
    Historical cemeteries are challenging targets for geophysical prospection but some non-destructive imaging techniques may be successful for mapping buried cemeteries if applied appropriately. Ground-Penetrating-Radar (GPR) has generally been considered to be the only geophysical method for determining cemeteries; however, Electrical-Resistivity-Tomography (ERT) and Magnetic-Imaging (MI), may determine geophysical traces of such cemeteries. Thus, as a first attempt at applying geophysical methods in the cemetery area of the Gallipoli Peninsula, these techniques were used to explore the buried graves at Agadere Cemetery. In this study, measured apparent resistivity data were processed using a two-dimensional (2D) tomographic inversion scheme. Resultant resistivity depth slices and volumetric resistivity images clearly showed the anomaly zone, which may be attributed to anthropogenic burials. Additionally, three-dimensional (3D) visualization of GPR results indicated some anomalies, much like the resistivity anomalies in terms of location. MI data were processed using linear transformations and an analytic signal image map presented anomaly zones located in some parts of the area, which are in agreement with those obtained by ERT and GPR surveys. Results derived from data processing techniques showed that these methods are suitable for bordering the locations of other buried historical graves in areas that have the same geological environment in the Peninsula.
  • [ X ]
    Öğe
    Hydrochemistry and Environmental Impacts of Kestanbol Geothermal Fluid
    (Tmmob Jeoloji Muhendisleri Odasi, 2020) Marmara, Harika; Yucel, Deniz Sanliyuksel; Özden, Süha; Yucel, Mehmet Ali
    Kestanbol geothermal field, located in the ancient town of Alexandria Troas, is at the contact between plutonic intrusions and neighboring metamorphic rocks in the Biga Peninsula. This area is also controlled by an ENE-WSW striking right lateral strike-slip fault segment representing the extension of the southern branch of the North Anatolian Fault to the west and is one of the geothermal fields with highest temperature in the Biga Peninsula. Kestanbol geothermal fluid from a well is used to heat facilities for thermal tourism and balneological purposes. The geothermal fluid continuously seeps into the environment with low flow rate and additionally, wastewater from the facility is discharged into Ilica stream. This study was conducted to determine the hydrochemical characteristics of the well and springs located in Kestanbol geothermal field and to evaluate the environmental effects of geothermal fluids on the soil and stream sediment. The temperature, electrical conductivity (EC) and pH of Kestanbol geothermal fluids are 59.5-74.1 degrees C, 30.3-35.5 mS/cm, and 6.45-6.71, respectively. The geothermal fluids are NaCl water type, with mean NaCl concentration of 19511 mg/L. In addition to higher EC values, and total dissolved solid content, Na+, Cl-, B, Ba, Fe and Mn concentrations of the Kestanbol geothermal fluid are above the tolerance limit of TS 266. Moreover, the geothermal fluid is heavily polluted water (class IV) according to the Turkish Inland Water Quality Regulations in terms of EC, Na+, Cl-, B and Fe. There is a scaling problem in the Kestanbol geothermal field. XRD and SEM-EDX analyses identified the minerals causing scale as calcite, halite and siderite. Arsenic, Fe and Mn concentration of scale, soil and stream sediment samples are higher than the mean value of world continental crust. According to the enrichment factor and geoaccumulation index, the geothermal fluid with intense rock interaction enriches soil and stream sediment in terms of As and Mn metal(loid)s as a result of discharge. It is recommended that geothermal fluids and waste waters from the facility should not be discharged into the soil and Ilica stream.
  • [ X ]
    Öğe
    Monitoring of Icelandic plate movement with GNSS method and GPS signal jamming effects in Iceland
    (Sciendo, 2023) Pirti, Atinc; Hosbas, Ramazan Gursel; Yucel, Mehmet Ali
    Jamming is electromagnetic radiation or reflection that impairs the function of electronic instruments and equipment or communication tools. Intentionally disrupting or interfering with GPS signals, which are used for positioning, navigation, and timing, known as GPS jamming, is accomplished using a radio frequency emitting device. On January 8, 2022 (the day of a NATO exercise), it was investigated how GPS signal jamming affected the position accuracy at three IGS points in Iceland. The obtained coordinate differences between kinematic processing and static processing reached values of about 0.5-10 meters for the MAYV, and HOFN stations in this study. In addition to GPS signal jamming effect in Iceland, horizontal and vertical velocity fields of the three IGS stations in Iceland covering a twenty-two year period (2000-2022) in this study. According to the obtained results, a motion of about 2cm-2.5cm per year (horizontal) and 0.1cm-2.1cm per year (vertical) was computed at the three IGS stations (HOFN, REYK, and MAYV) located in Iceland.
  • [ X ]
    Öğe
    TESTING REAL TIME KINEMATIC GNSS (GPS AND GPS/GLONASS) METHODS IN OBSTRUCTED AND UNOBSTRUCTED SITES
    (Assoc Surveyors Slovenia, 2013) Pirti, Atinc; Yucel, Mehmet Ali; Gumus, Kutalmis
    This paper describes an experiment carried out with the GNSS RTK method to combine GPS and GLONASS measurements in obstructed and unobstructed sites. This study investigates the RTK achievable accuracy and repeatability under different satellite constellations and site conditions in Samatya (coastal area), Istanbul, Turkey. The RTK (GPS and GPS/GLONASS) measurement techniques are described and compared in terms of productivity and precision. Surveyed area, control and test points as well as the impact area of trees where the precision decreases are visualised using Autodesk LandXplorer Studio ProfessionalTM Software. These obtained results indicate that integrating RTK GPS system with GLONASS is favoured for surveying applications.
  • [ X ]
    Öğe
    TESTING THE EXCAVATOR PERFORMANCE (USING TOPCON 3D EXCAVATOR X63 SYSTEM) ESPECIALLY FOR NAVIGATION AND EARTHWORK
    (Vilnius Gediminas Technical University, 2023) Pirti, Atınç; Yazici, Muharrem; Yucel, Mehmet Ali
    Construction sites commonly utilize bulldozers, wheel loaders, excavators, scrapers, and graders. Among these, excavators are versatile hydraulic heavy-duty equipment operated by humans. They are employed for various tasks like digging, levelling the ground, transporting and dumping loads, as well as providing straight traction. However, certain hazardous environments, such as nuclear disasters or earthquakes, are not suitable for human on-site work. To enhance productivity, accuracy, and profitability in excavation projects, the adoption of 3D machine control is recommended. The Topcon 3D Excavator X63 System offers advanced and precise GNSS positioning technology, coupled with Hidromek with Assist and an intuitive software interface, to significantly improve excavation operations. In this study, the accuracy of the coordinates of the route followed by the Excavator was checked by using RTK GNSS method by using P1 reference point. While the differences obtained in horizontal coordinates are 2–2.5 cm and 4–6 cm in vertical coordinates. In addition, excavation calculations of the earthwork area were performed and checked with the number of bucket of the excavator. The differences obtained from the earthwork were calculated as 0.8 cubic meters for each bucket. © 2023 The Author(s). Published by Vilnius Gediminas Technical University.
  • [ X ]
    Öğe
    TRANSRAPID AND THE TRANSITION CURVE AS SINUSOID
    (Univ Osijek, Tech Fac, 2016) Pirti, Atinc; Yucel, Mehmet Ali; Ocalan, Taylan
    The transition curves in the modern highway and railway construction are route elements equally crucial as alignment and curve (circular). In order to prevent a sudden change of the centrifugal force, the transition curve must be applied due to the impact of the motion in a sharp curve. Over the years the application of the clothoid has become widespread in many countries in the world. However, in this study, in order to eliminate the problems concerning the road dynamics, created by clothoid for vehicles at high speed, sinusoid is examined. The possibility of using sinusoid in defining transition curves during design of transportation facilities is analysed in this paper. Basic properties of sinusoid, their fundamental mathematical expression, calculation of point coordinates, driving-dynamic characteristics of sinusoid are described (especially for Transrapid using), and the function of change in curvature and lateral impact along the sinusoid is presented. Sinusoid is dealt with as ideal curvature diagram which has curve and superelevation ramp in the articles.