Denizhan Mersin

Nowadays, intensive work is being done on the evaluation of household waste and during the production of various products. This study compiles studies investigating the usability of wastes such as marble dust, fly ash, phosphogypsum, and glass dust in asphalt pavement mixtures. Marshall stability samples were prepared by using asphalt cement at 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, and 6.5 ratios to determine the optimum binder ratio. The optimum bitumen percentage was determined by applying the Marshall stability test to the prepared samples. Marshall stability test was applied to the samples for the optimum bitumen percentage found as 4.9%. The variation of Marshall stability and yield values in bituminous mixtures using industrial waste fillers were investigated. In addition, the usability of used engine oils in the modification of bituminous binders has also been mentioned. For this purpose, bitumen was modified by mixing horse engine oil in 5 different ratios ranging from 1% to 5% from 70/100 penetration class to bitumen using a standard method. The changes in the bitumen as a result of the modification were investigated on basic engineering properties such as penetration, softening, flash point, and viscosity. At the same time, it was revealed how the temperature sensitivity of the bitumen and the mixing and compaction temperatures changed after the bitumen was modified with used engine oil. In addition, the modification index is defined for each test method. As a result, a significant change has occurred in the basic engineering properties of the modified bitumen samples using different ratios of used engine oil additives. It was determined that the softening point, flash point, and viscosity values of the bitumen with an increase in the penetration value were decreased. According to the evaluations made on the basic engineering properties of bitumen, it was predicted that it would be possible to recycle used engine oils by using them in bitumen modification.

Soils intended to support structures, pavements or other loads should be evaluated by geotechnical engineers to predict their behavior under conditions of applied forces and varying humidity. Soil mechanics tests in geotechnical laboratories measure particle size distribution, shear strength, moisture content, and the potential for expansion or contraction of cohesive soils. Atterberg limit tests determine the moisture content at which fine-grained clay and silt soils transition between solid, semi-solid, plastic and liquid states. Artificial neural networks (ANN) is an information processing technology inspired by the information processing technique of the human brain. In this study, the determination of the Atterberg limits, which are frequently used for the determination of soil properties in geotechnical engineering and their comparison with experimental data, were determined and the results showed a very similar pattern.

As in all areas of technology, an increase is observed in the production and use of innovative materials in engineering applications. Geosynthetics are materials produced from polymeric materials and are widely used in civil engineering, and the main ones can be listed as geonet, geomembrane, geotextile, geogrid, geocomposite, geofoam, and geocell. Conservation of resources and energy in the realized applications and existing projects necessitates the preference for quality geosynthetic materials and qualified geosynthetic applications to ensure sustainability. Transportation engineering, which is a branch of civil engineering, covers roads (pavements), airports, ports, and railways. Besides, geosynthetic materials increase the performance and design (economic) life of transportation structures, especially in areas where soil strength (capacity) is weak. Geosynthetics offer much higher value than conventional road construction products and greatly reduce construction with a fast, simple installation process. This study reviews the various functions and benefits of several geosynthetic material types in transportation structures.

The effects of climate change on the water resources of the Izmir which is in the Aegean Region in Turkey are investigated through trend analysis of yearly temperature (daily average) and total precipitation time series data gathered from 3 stations (Izmir, Seferihisar, Cesme) in the research region. The techniques of Sen, Mann-Kendall, and Spearman's rho test are employed to identify historical patterns in the area. Theil-Sen technique is used to identify the change point(s) in the time series, while the Pettitt test is used to determine the size of the slope in the time series. Results show statistically significant trends of an increasing character in the temperature and precipitation time series at the chosen station. The rate of rising in precipitation and temperature was determined using the Theil-Sen test to be 7.3 - 7.9 mm/year and 0.2 - 0.3 °C/decade, respectively. Additionally, it was found that 1998 was the year for all sites where the change points in the temperature trends identified by the Pettitt test occurred. By considering the findings, a framework to boost climate change resilience will be required since the scale of severe occurrences will alter in the future.

Kuraklık İndeksleri, kuraklığın süresini ve şiddetini gözlemlemek için yaygın olarak kullanılmaktadır. Günümüzde sürekli olarak yaşadığımız iklim değişikliği, su kıtlığının (yetersizliğinin) sınırlarını zorlamaktadır. İzmir ve Aydın, deniz kıyı alanları, göller, akarsular ve yeraltı suyu gibi çeşitli su kaynaklarına sahip olan, Türkiye’nin yükselen ve nüfusu sürekli artan ve ayrıca tarımsal olarak da ön plana çıkan illeridir. Bu nedenle, kuraklığın değerlendirilmesi önemli bir yer teşkil etmektedir. Şimdiye kadar, yapılan bazı çalışmalar bulunmaktadır. Bu çalışmada, önceki çalışmalardan farklı olarak Türkiye’nin Ege bölgesindeki Büyük Menderes, Küçük Menderes ve Gediz havzalarında kuraklık özelliklerini araştırmak için 1973-2020 yılları arasında (47 yıl) toplamda 14 farklı istasyonun uzun süreli yağış ve sıcaklık kayıtları kullanılmıştır. Aynı zamanda, Standart Yağış İndeksi (SPI) ve Standart Yağış ve Evapotranspirasyon İndeksi, kuraklık modellerini araştırmak için 1, 3, 6 ve 12 aylık hareketli ortalama zaman dilimlerinde kullanılmıştır. Sonuçlar, 1 aylık hareketli ortalama endekslerinin incelenen havzalarda hemen hemen aynı sonuçları verdiğini ve genel olarak 1980’ler ve 2005-2010 yılları arasındaki kuraklığın diğer yıllara göre daha fazla olduğunu göstermiştir.
Ancak, daha uzun periyotlar olan 3, 6 ve 12 aylık hareketli ortalama periyotlarında tüm istasyonlar için SPEI ve SPI yöntemi aynı sonucu göstermemekte olup, şiddetli kuraklık dönemleri olmasına rağmen, genel ortalamada kuraklık normal seviyelerde kalmıştır.

Drought is one of the most important phenomenon related to the agriculture-food and socioeconomic problems all over the world. The Aegean region has a variety of water resources, including but not limited to seacoasts, lakes, streams, and groundwater aquifers. For this reason, the evaluation of historical and future drought events and their effects on water resources is important in the planning and development of the region. In this context, this study aims to evaluate the historical droughts in the inner Aegean region. Monthly precipitation time series were used in three meteorology stations, which are in the Büyük Menderes basin and have a continental climate, recorded between 1973 and 2020. First, to figure out whether the drought analysis is correct and dependable, consistency, randomness, and trend in time series were investigated using the binary mass curve, run and linear trend tests. Next, the standardized precipitation index SPI is used in conjunction with the moving average (MA) operator to evaluate the historical gap associated with meteorological (SPI-1), agricultural (SPI-3), and hydrological (SPI-6 and SPI-12). Finally, the results are evaluated based on the behavior of the SPI time series at different time intervals.

Drought indices are commonly used to monitor the duration and severity of droughts. In this regard, the continuously changing climate regardless of its cause or effect pushes the limit of the water deficit through time and space. Izmir is a raising city in Turkey, which owns various water resources including but not limited to seashores, lakes, river streams, and groundwater aquifers. In this study, the long-term precipitation and temperature records from 14 meteorological stations between 1973 and 2020 (for 47 years) are used to investigate the drought characteristics in Buyuk Menderes, Kucuk Menderes, and Gediz basins located in the Aegean region of Turkey. For this, the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI), Percent of Normal (PNI), and the so-called Discrepancy Precipitation Index (DPI) are used with consideration to 1-, 3-, 6-, and 12-month moving averages to investigate the drought patterns. Results showed that the monthly indices depict very similar results for the entire region. However, in the 1980s and 2010s droughts were more severe than the rest of the historical records. When the moving average operator is implemented in the analysis (3-, 6- and 12-month periods), neither SPI nor the SPEI showed the same results at any stations. It is illustrated that the periods of severe and normal drought have occurred in the past, yet the indices that are obtained using average values are generally within the normal limits, but extreme values (extremely arid or extremely wet) occurred occasionally. It is also concluded that although there is a similarity between the implemented indices, the DPI and PNI depict the highest resemblance.

Drought indices are widely used in order to track the severity, duration, and frequency of droughts, drought indices are frequently utilized. Turkey's Aegean region, which is expanding, has a range of water resources, including lakes, streams, lakes, and groundwater aquifers. In this study, the drought features in the Büyük Menderes, Küçük Menderes, and Gediz basins in the Aegean area of Turkey are investigated using long�term total precipitation and temperature records from 14 meteorological stations between 1973 and 2020 (47 years). For this, the Standardized Precipitation Index (SPI) and the Standardized Precipitation and Evapotranspiration Index (SPEI), and Discrepancy Precipitation Index (DPI) are used to investigate drought patterns, monthly and over 3-, 6-, and 12-month (annual) periods. The results reveal that the monthly indices show almost the same results for the whole study area, but the different indices differ in the severity of drought. As a common belief, moderate, severe, and extreme drought is observed at the end of the 1980s and around 2020, which is the closest year to the present. In addition, the trend analysis of the annual temperature (daily average) and total precipitation time series data collected from these 14 stations is examined. Sen test, Mann-Kendall test, and Spearman's rho test are used for trend detection. The Pettitt test is used to estimate the magnitude of the slope in the series and the Theil-Sen approach is used to detect the change point of the series. For precipitation, all stations showed a statistically significant increase in trends. In the temperature analysis, on the other hand, all stations show statistically significant increasing trends in daily average temperatures. The amount of precipitation increase determined by the Theil-Sen test is found to be between 4.2 and 7.9 mm/year.