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Öğe A review on alternative hydropower production methods(Batman Üniversitesi, 2018-09-18) Muratoğlu, AbdullahIncreasing energy prices, exponentially growing power need and detrimental effects of conventional fossil fuel consumption has lead scientists and engineers to find alternative and clean ways of energy production. Hydropower is one of the clean and renewable energy extraction methods providing very high potential of energy with considerably high predictability. Conventional hydroelectric plants (HEPP) are quite old technique of energy production covering about one fifth of electricity need of the world. Hydroelectric energy is site specific and most of the suitable locations for HEPPs are already exploited. Also the conventional technology have high amount of civil works together with serious environmental impacts. In this study, both conventional and alternative hydropower production methods were reviewed with special emphasize on modern technology and processes. Run-of-river hydropower production schemes, tidal energy and other in-stream energy conversion systems, wave energy technologies, ocean thermal and osmotic power stations were analyzed. The methodology and device mechanisms were investigated.Öğe Fresh and hardened properties of self consolidating Portland limestone cement mortars: Effect of high volume limestone powder replaced by cement(Elsevier, 2019-01-30) Demirhan, Serhat; Türk, Kazım; Ulugerger, KübraThe main purpose of this experimental study is to elucidate the performance of self-compacting mortars (SCMs) composed of high volume limestone powder (LSP). In accordance with this purpose, four different SCMs at which limestone content varied as 0%, 15%, 25% and 35% were designed and later on fresh, hardened and durability properties of the mixtures were investigated for different curing ages depending on the testing method. Compressive strength, splitting tensile strength, rheological properties, mini-slump cone, carbonation, UPV and capillary water absorption were investigated in terms of fresh and hardened performance properties. In term of fresh properties, test results showed that there was a clear increase in the yield stress up to LSP content of 15% and beyond this level there was a tendency of reduction of the yield stress with the increase of limestone addition and also slumps values increased and pointed out a satisfactory fresh property in accordance with the increase in the replacement level of LSP. For mechanical properties, there was a steady decrease in the compressive strength values with the increase in LSP content while the addition of LSP in SCMs more than 15% did not improve splitting tensile strength of the mixtures for all curing ages. As a durability property, carbonation resistance of SCMs samples decreased with the increase in LSP replacement level for all of the mixtures and also UPV values were in an acceptable range of good (for 15%) and doubtful (for 35%) category intervals. Furthermore, the control mixture with the only PC had the lowest sorptivity coefficient as 2.73 cm/s1/2 followed by SCMs with 15%, 25% and 35% LSP as 5.11, 6.13 and 6.14 cm/s1/2, respectively.Öğe Water footprint assessment within a catchment: A case study for Upper Tigris River Basin(Elsevier, 2019-11) Muratoğlu, AbdullahSubstantial amount of world's population experiences severe water scarcity problems. The water scarcity related threats on food security, human health and natural ecosystem are estimated to increase in the future, due to unconscious use and overutilization of water resources. Water footprint assessment studies at basin level are very important and provide a key role for sustainable development of freshwater resources especially in arid and semi-arid regions. However, comprehensive studies on water footprint assessment of river basins are quite limited due to requirement of wide-range of statistical data. The main scope of this study is to analyze the blue and green water footprint of Upper Tigris River Basin (UTRB, Turkey) with a bottom-up approach for the years between 2010 and 2018. Water footprints of agricultural production, livestock production and industrial plus domestic water use have been separately studied. Total blue and green water footprints, per capita water footprints and virtual water contents of the major crops harvested in the UTRB were calculated and compared with surrounding countries. A sustainability assessment based on the scarcity indicators has also been provided. Annual water footprint of UTRB is calculated as 7.2 Gm3/yr for the specified time interval corresponding 1748 m3/cap/yr. Crop production has the highest share with 79% of total water footprint. Wheat is the primary crop cultivated in the study area and responsible for 45% of consumptive water use of all crops. The livestock and domestic plus industrial water footprint were obtained as 16% and 5% of the complete basin's water footprint, respectively. Annual blue water scarcity of the basin is obtained to be 87% which is classified as low scarcity. The findings of this study are expected to increase water allocation efficiency and sustainability of the study area. It is also expected to contribute the integrated basin management studies and cooperation between riparian countries for better planning and management of transboundary water resources.Öğe Financial comparison of the Kyoto Protocol obligations and the natural disaster losses(Batman Üniversitesi, 2017) Batan, Murat; Toprak, Zeynel FuatThe global climate change (GCC) has occupied the world’s attention in the last few decades. It has serious impacts on all aspects of the life (i.e. ecology, energy, global economy, etc.)It directed the scientists, politicians and non-governmental civil society organizations towards adaptation, mitigation and combat with the problem. It has signed for this purpose both United Nations Framework Convention on Climate Change (UNFCCC) and Kyoto Protocol (KP) have been signed in 1992 and 1997, respectively. In this study, by considering a mediumterm target, the impact percentage of the USA on global climate change is projected approximately as 20% for the year 2030. In this content, the financial obligations due to Kyoto Protocol of USA with the cost of natural disasters on USA economy is compared. In this comparison, It has been considered only financial damages of natural disasters. It has not considered the human deaths. As a result, if USA approve the protocol and fulfill the financial obligations arising from Kyoto Protocol; it can reached to conclude that USA will have more profits on the long run.Öğe Estimating the long term average flow rates of tigris basin using machine learning methods(Batman Üniversitesi, 2016) Muratoğlu, Abdullah; Yüce, Mehmet İshakThe discharge of a river is one of the most important parameters of the hydraulic and hydrological studies such as hydropower production, canal design, irrigation, basin management. Each basin has different climate and geological characteristics which influence the regional infiltration capacity and runoff. The aim of this study is to estimate the average annual flow rates of ungauged locations on the Tigris River Basin. In total, eleven machine learning methods were applied to the long-term average annual discharge and the drainage area data of 34 flow measurement stations (FMS). Among all methods employed here, the conventional regression analysis was found to be the most successful test with a correlation coefficient (R 2 value) of 0.96. The equation of the best fitted linear line represents the relationship between the drainage area and the discharge. The results of this study are expected to enable the prediction of the average annual flow rate of any sub-basin of the Tigris River.Öğe Fresh and hardened properties of self consolidating Portland limestone cement mortars: Effect of high volume limestone powder replaced by cement(Elsevier, 2018-11-21) Demirhan, Serhat; Türk, Kazım; Ulugerger, KübraThe main purpose of this experimental study is to elucidate the performance of self-compacting mortars (SCMs) composed of high volume limestone powder (LSP). In accordance with this purpose, four different SCMs at which limestone content varied as 0%, 15%, 25% and 35% were designed and later on fresh, hardened and durability properties of the mixtures were investigated for different curing ages depending on the testing method. Compressive strength, splitting tensile strength, rheological properties, mini-slump cone, carbonation, UPV and capillary water absorption were investigated in terms of fresh and hardened performance properties. In term of fresh properties, test results showed that there was a clear increase in the yield stress up to LSP content of 15% and beyond this level there was a tendency of reduction of the yield stress with the increase of limestone addition and also slumps values increased and pointed out a satisfactory fresh property in accordance with the increase in the replacement level of LSP. For mechanical properties, there was a steady decrease in the compressive strength values with the increase in LSP content while the addition of LSP in SCMs more than 15% did not improve splitting tensile strength of the mixtures for all curing ages. As a durability property, carbonation resistance of SCMs samples decreased with the increase in LSP replacement level for all of the mixtures and also UPV values were in an acceptable range of good (for 15%) and doubtful (for 35%) category intervals. Furthermore, the control mixture with the only PC had the lowest sorptivity coefficient as 2.73 cm/s1/2 followed by SCMs with 15%, 25% and 35% LSP as 5.11, 6.13 and 6.14 cm/s1/2, respectively.Öğe Rate effects on the undrained shear strength of compacted clay(Japanese Geotechnical Society, 2016-08-01) Mun, Woongju; Teixeira, T.; Balcı, Mehmet Can; Svoboda, Jenna S.; McCartney, John S.Unconsolidated-undrained (UU) triaxial compression tests were performed on low-plasticity clay specimens compacted to the same void ratio but different initial degrees of saturation to evaluate the impact of axial strain rates ranging from 0.1 to 150%/min on the undrained shear strength. Although an effective stress analysis cannot be performed on the results, they are useful to evaluate the relative roles of initial hydraulic conditions (i.e., matric suction and degree of saturation) and compaction effects (i.e., potential changes in soil structure with compaction water content). This evaluation is relevant due to difficulty in measuring shear-induced pore water and air pressures in consolidated-undrained (CU) compression tests on unsaturated clay. In all tests, the undrained shear strength quantified as the maximum principal stress difference increased log-linearly with axial strain rate, with rates of increase ranging from 4.1 to 9.7% per log cycle of axial strain rate for specimens having initial degrees of saturation ranging from 0.99 to 0.59. The undrained shear strength, rate of increase in undrained shear strength with axial strain rate, and secant moduli all increased nonlinearly with decreasing initial degree of saturation, although compaction effects played an important role in these trends. The increase in undrained shear strength with axial strain rate can be attributed to a reduction in the magnitude of excess pore water pressure, with similar reductions in magnitude for all the degrees of saturation considered. A comparison between the measured undrained shear strength values and the drained shear strength values estimated using the suction stress concept was useful in delineating the impacts of initial hydraulic conditions and compaction effects on the trends in measured undrained shear strength.
