TR Dizin İndeksli Yayınlar / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7149
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Article The Relationship Between Transportation Demand and Supply: Granger-Causality Test Using Time-Series Data(Pamukkale Üniversitesi, 2022) Duvarcı, Yavuz; Duran, Hasan EnginTransport demand and supply are deemed to determine each other in a cyclic manner. The major idea has been that the demand is usually the preceding one. However, in urban cases, usually the land use variables in place of supply interfere this process. Cleansing the land use variables, the regional/national level variable pairs of demand and supply are employed to analyze the cause-effect mechanism. For objectivity, the Granger-causality test (GCT) is used to understand the relationship between transportation demand and supply. The Analyses were made at four dimensions; (a)whether the nexus is one-directional or bi-directional, (b)its significance level, (c)whether demand or supply is the preceding, (d)whether the effects are short-term or long-term. Using the Turkish statistics, the GCT results showed that, in the short/medium run, overwhelmingly the supply variables preceded (mostly in railway mode), mostly unidirectional (one-way causality) manner, however, in the long-run almost no relationship was found. In other transportation modes, no significant relationship is observed. Finally, bi-directional relations were usually observed in suburban rail. The investments then should be made according to known demand. Usually, the effects of supply (especially of railways and roadways) could rather fade away in the long-run. Still, no general statement can be made for the demand/supply causality especially in terms of which one is preceding and of the direction of causality. The chaotic nature of the process reigns over with the changing conditions.Article Determining Scenario Based Highway Routes Using Geographic Information Systems; a Case Study of Simav-Kutahya Routes, Turkey(Pamukkale Üniversitesi, 2014) Erdem, UmutTransportation planning requires more efforts from city planners to use rational techniques to determine optimum road routes. To fulfill this requirement, this study aims at generating the cheapest and the shortest scenario based routes using Geographic Information Systems (GIS) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Digital Elevation Model (DEM) with Least Cost Path analysis between the Simav and the Kutahya cities, and comparing them with existing routes. For generating the shortest and the cheapest route, these cities are selected as sample since the study region is located in the transition area between central Anatolia and Aegean Region which has access to the sea and regional ports. The methodology used in this study is composed of three parts: first part consists of two steps; (i) generating the factors and (ii) determining scenarios focusing on different transportation themes that are used in the study process. In second part all factors are weighed regarding scenarios. In the third part of the study the outputs Path A (cheapest) and Path B (shortest) are generated by Least Cost Path analysis. The output routes were compared not only with each other, but also with the existing routes in terms of the generated factors.Article Citation - WoS: 1Arsenate Removal From Groundwater by Air-Injected Ec With Al Ball Anodes: Effects of Operational Parameters(Pamukkale Üniversitesi, 2020) Gören, Ayşegül Yağmur; Öncel, Mehmet Salim; Kobya, MehmetTreatment of arsenate from groundwater by electrocoagulation (EC) reactor with air supply unit using Al ball electrodes were studied in this paper. Influence of some operating variables, for instance, applied current (0.075-0.3 A), initial pH (5.5-8.5), air flow rate (0-6 L/min), size of Al ball electrodes (5-10 mm), and height of electrode in EC reactor (2-8 cm) on the As(V) removal efficiency were evaluated. The As (V) removal efficiency increased with the increment of applied current, air flow, electrode altitude in EC reactor, and EC time while its removal efficiency decreased with the increment of size of Al ball electrodes. The maximum As(V) removal percentage, minimum operating cost and energy consumption were found as 98.68 %, 0.609 $/$m^3$ and 3.7694 kWh/$m^3$ at pH of 7.5, current density of 0.30 A, size of Al balls of 7.5 mm, height of electrode in EC of 5 c†m, and air flow rate of 6 L/min, respectivelyArticle Citation - WoS: 5Color Removal From Yeast Production Industry Wastewater Using Photo-Fenton Process(Pamukkale Üniversitesi, 2019) Baycan, Neva; Can, BegümThe yeast production industry wastewaters contains high amount of chemical oxygen demand (COD), brownish color and recalcitrant organic components. In this work, one of the yeast production plant wastewaters operating in the Aegean Region, the color removal were studied with using Photo-Fenton (H2O2/Fe(II)/UV) oxidation processes. In this study, the Box-Wilson statistical experimental design method applied to optimization of decolorisation of the yeast production industry wastewater. For this reason, the initial oxidant and catalyst concentrations and pH of water were chosen as the experimental parameters on decolorisation. Color removal was observed during the experimental studies. Complete color removal (E=100%) was achieved with the addition of 2400 mg/L H2O2 and 121 mg/L Fe(II) at 3.7 pH after 120 min. of exposure to the UV irradiation.Article Citation - WoS: 1Lateral Torsional Buckling of Doubly Symmetric I-Shaped Steel Members Under Linear Moment Gradient(Pamukkale Üniversitesi, 2019) Uzun, Ertuğrul Türker; Seçer, MutluDue to technical developments and wider range of applications in the steel structures, significance of the research on structural stability problems become forward. Lateral torsional buckling is a major problem especially for doubly symmetric I-shaped steel members subjected to flexure about their strong axis. If these members are not appropriately braced against lateral deflection and twisting, they are under the risk of failure by lateral torsional buckling prior to the reach their load carrying capacity. In this study, elastic lateral torsional buckling behavior of doubly symmetric I-shaped steel members under linear moment gradient is investigated considering a proposed method, several design standards and codes, approaches from the literature and finite element analysis. Proposed method herein is based on finite difference solution of lateral torsional buckling differential equation considering linear moment gradient. Different unbraced member lengths and various end moment values are considered in order to compare and evaluate these approaches in terms of critical moment and moment modification factor. Analysis results show that lateral torsional buckling is a key issue for doubly symmetric I-shaped steel members that are under flexure and it is reflected satisfactorily with the proposed method considering the design codes and standards, approaches from the literature and finite element analysis results.