Search Results

Now showing 1 - 7 of 7
  • Article
    Citation - WoS: 29
    Citation - Scopus: 36
    Fixed Point Results on a Class of Generalized Metric Spaces
    (Springer Heidelberg, 2012) Aydi, Hassen; Karapinar, Erdal; Lakzian, Hossein
    Brianciari ('A fixed point theorem of Banach-Caccioppoli type on a class of generalized metric spaces,' Publ. Math. Debrecen 57 (2000) 31-37) initiated the notion of the generalized metric space as a generalization of a metric space in such a way that the triangle inequality is replaced by the 'quadrilateral inequality,' d(x, y) <= d(x, a) + d(a, b) + d(b, y) for all pairwise distinct points x, y, a, and b of X. In this paper, we establish a fixed point result for weak contractive mappings T : X -> X in complete Hausdorff generalized metric spaces. The obtained result is an extension and a generalization of many existing results in the literature.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 5
    A Long-Run Convergence Analysis of Aerosol Precursors, Reactive Gases, and Aerosols in the Brics and Indonesia: Is a Global Emissions Abatement Agenda Supported?
    (Springer Heidelberg, 2023) Romero-Avila, Diego; Omay, Tolga
    This article examines the hypothesis of deterministic emissions convergence for a panel of the BRICS and Indonesia to advanced countries' emissions levels as well as to Sweden (which is a country that has clearly gone through decoupling) using a novel dataset with ten series of annual estimates of anthropogenic emissions comprising aerosols, aerosol precursor and reactive compounds, and carbon dioxide from 1820 to 2018. For that purpose, we employ four novel panel unit root tests allowing for several forms of time-dependent and state-dependent nonlinearity. The evidence supports deterministic convergence following a linear process for carbon dioxide, whereas the adjustment is asymmetric and nonlinear for carbon monoxide. Methane and nitrogen oxides exhibit logistic smooth transition converging dynamics. In contrast, black carbon, ammonia, nitrous oxide, non-methane volatile organic compounds, organic carbon, and sulfur dioxide emissions diverge. These results have implications for the abatement of greenhouse gases emissions at the global level, given the high share of emissions of the BRICS.
  • Article
    Citation - WoS: 159
    Citation - Scopus: 164
    Economic Policy Uncertainty, Energy Consumption and Carbon Emissions in G7 Countries: Evidence From a Panel Granger Causality Analysis
    (Springer Heidelberg, 2020) Pirgaip, Burak; Dincergok, Burcu
    We investigate the causal relationship between economic policy uncertainty (EPU) and energy consumption and carbon (CO2) emissions in G7 countries. We employ a bootstrap panel Granger causality test developed by Konya (Econ Model 23:978-992, 2006), using a yearly data set spanning from 1998 to 2018. Our test results provide significant support for a unidirectional causality running from EPU to energy consumption in Japan; from EPU to CO2 emissions in the USA and Germany; and from EPU to both energy consumption and CO2 emissions in Canada. In Italy, causality runs from CO2 emissions to EPU, but a bidirectional causality between EPU and energy consumption exists as well. We also explore a unidirectional causality that runs from energy consumption to CO2 in the USA. Based on the overall findings, we draw important implications for policymakers and we strongly recommend for G7 countries to take into account possible negative effects of EPU on energy conservation policies, which should be embarked upon to reduce energy consumption and CO2 emissions, as committed in their recent climate mandate.
  • Article
    Citation - WoS: 9
    Citation - Scopus: 10
    Determination of the Relationship Between Uniaxial and Triaxial Swelling Equations for Clay Bearing Rocks
    (Springer Heidelberg, 2013) Bilir, M. Erdinc; Sari, Y. Dursun; Ozarslan, Ahmet; Genis, Melih; Sel, Ibrahim
    Design in swelling mediums is mostly based on uniaxial data since the standards proposed by the International Society for Rock Mechanics Commission on Swelling Rocks for uniaxial tests are in the form of recommendations, triaxial sets are not highly available; and there is no standard developed for triaxial tests. The main purpose of this study is to define the relationship between the uniaxial and the triaxial swelling equations and to predict the triaxial values using the uniaxial data. The other purpose of the study is to contribute to the development of the standards and to expand the data available in the literature about triaxial swelling behavior. Numerous uniaxial and triaxial swelling tests were performed on the samples from seven different locations, in Turkey, in a state of the art swelling laboratory. As a result of the determination of the triaxial swelling behavior of these samples, the relationships between the uniaxial and the triaxial swelling data for the individual samples as well as the whole set of samples are expressed by the equations derived from the statistical analyses.
  • Article
    Citation - WoS: 12
    Citation - Scopus: 11
    Integrated Approach for Determining Spatio-Temporal Variations in the Hydrodynamic Factors as a Contributing Parameter in Landslide Susceptibility Assessments
    (Springer Heidelberg, 2019) Canoglu, Mustafa Can; Aksoy, Husnu; Ercanoglu, Murat
    Although general approaches to the effect of water on the mechanisms causing landslides have been adopted, the work presented in this paper was carried out to quantify the landslide susceptibility variation in space and time, integrating the soil moisture distribution and routing (SMDR) model and landslide susceptibility concept. The approach proposed in the present study reflects the temporal effects of the saturation degree index (SDI) on landslide susceptibility as a new index to understand the effect of soil saturation. The topographic wetness index (TWI) is a conventional parameter that represents the relative wetness on landsliding. The new proposed landslide susceptibility approach is used in the study area to understand the effect of soil saturation and the emergence of the Dereba landslide in the study area. The comparative results of landslide susceptibility maps obtained from the new approach utilizing the proposed SDI and conventional TWI are remarkable. Accordingly, a new substantial method is proposed using the attainable monthly mean meteorological data to generate monthly landslide susceptibility maps. The results obtained for the Dereba landslide using the proposed method are validated with the other landslide that has occurred in the same watershed. The results revealed that the approach proposed in this study was compatible with the landslide mechanism in the study area and may help to express the water effect in landslide susceptibility analyses.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 6
    Consistency of Spatiotemporal Variability of Modis and Era5-Land Surface Warming Trends Over Complex Topography
    (Springer Heidelberg, 2023) Yilmaz, Meric
    In this study, the trend of widely used MODIS MxD11 and MxD21 Land Surface Temperature (LST) and ERA5-Land Skin Temperature (SKT) and 2 m air temperature products were validated using 2 m air temperature trends obtained by ground observations from 266 stations in 2000-2021 over Turkey, known to have complex topography. The results show that colder regions have substantially higher temporal temperature variability than warmer ones. MxD21 and MxD11 products are 4.4 & DEG;C and 2.9 & DEG;C warmer than ERA5-Land products, respectively, while ERA5-Land products (SKT and 2 m) have nearly similar averages (12.5 & DEG;C). The consistency between MODIS and ERA5-Land data is significantly lower over areas with more complex topography and irrigation activities, despite the fact that the products show a high linear relationship over the study area. While February trends are consistently much higher than other months (2.2 and 1.4 & DEG;C/decade for MODIS and ERA5-Land, respectively), overall MODIS skin temperature products (0.7 & DEG;C/decade) generally exhibit smaller trends than ERA5-Land skin and air temperature trends (0.94 & DEG;C/decade). The results suggested that MODIS and ERA5-Land trends, which are highly consistent with observations, might replace observations in the absence of long-term station-based records.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 6
    The Effects of Energy-Intensive Meat Production on Co2 Emissions: Evidence From Extended Environmental Kuznets Framework
    (Springer Heidelberg, 2022) Bor, Ozgur; Omay, Tolga; Iren, Perihan; Aktan, Ceyda
    This study documents the positive relationship between meat production and CO2 emissions by utilizing the environmental Kuznets framework. Relationships between energy consumption, economic growth, meat production, and the levels of CO2 are tested using 6 different variables (CO2 emissions, GDP, energy consumption, forest area, total meat, and total livestock). Data for the study is related to the G7 countries and covers the period between 1961 and 2016. The analysis of the data is then conducted using a panel threshold model. Moreover, the extended EKC model does not only consider the income as the state variable but also examines the nonlinear structure inherited in other explanatory variables as a state variable. In this way, we have seen the nonlinear effects of other variables' evolution over time on carbon emission. The overall results indicate that the production of meat significantly increases CO2 emissions.