421 research outputs found

    Industrial Electricity Demand for Turkey: A Structural Time Series Analysis

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    This research investigates the relationship between Turkish industrial electricity consumption, industrial value added and electricity prices in order to forecast future Turkish industrial electricity demand. To achieve this, an industrial electricity demand function for Turkey is estimated by applying the structural time series technique to annual data over the period 1960 to 2008. In addition to identifying the size and significance of the price and industrial value added (output) elasticities, this technique also uncovers the electricity Underlying Energy Demand Trend (UEDT) for the Turkish industrial sector and is, as far as is known, the first attempt to do this. The results suggest that output and real electricity prices and a UEDT all have an important role to play in driving Turkish industrial electricity demand. Consequently, they should all be incorporated when modelling Turkish industrial electricity demand and the estimated UEDT should arguably be considered in future energy policy decisions concerning the Turkish electricity industry. The output and price elasticities are estimated to be 0.15 and -0.16 respectively, with an increasing (but at a decreasing rate) UEDT and based on the estimated equation, and different forecast assumptions, it is predicted that Turkish industrial electricity demand will be somewhere between 97 and 148 TWh by 2020.Turkish Industrial Electricity Demand; Energy Demand Modelling and Forecasting; Structural Time Series Model (STSM); Future Scenarios.

    Modelling and Forecasting Turkish Residential Electricity Demand

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    This research investigates the relationship between Turkish residential electricity consumption, household total final consumption expenditure and residential electricity prices by applying the structural time series model to annual data over the period 1960 to 2008. Household total final consumption expenditure, real energy prices and an underlying energy demand trend are found to be important drivers of residential electricity demand with the estimated short run and the long run total final consumption expenditure elasticities being 0.38 and 1.57 respectively and the estimated short run and long run price elasticities being -0.09 and -0.38 respectively. Moreover, the estimated underlying energy demand trend, (which, as far as is known, has not been investigated before for the Turkish residential sector) should be of some benefit to Turkish decision makers in terms of energy planning. It provides information about the impact of the implementation of past policies, the influence of technical progress, the changes in consumer behaviour and the effects of energy market structure. Furthermore, based on the estimated equation, and different forecast assumptions, it is predicted that Turkish residential electricity consumption will be somewhere between 48 and 80 TWh by 2020 compared to 40 TWh in 2008.Turkish Residential Electricity Demand, Structural Time Series Model (STSM), Future Scenarios, Energy Demand Modelling and Forecasting.

    Turkish Aggregate Electricity Demand: An Outlook to 2020

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    This paper investigates the relationship between Turkish aggregate electricity consumption, GDP and electricity prices in order to forecast future Turkish aggregate electricity demand. To achieve this, an aggregate electricity demand function for Turkey is estimated by applying the structural time series technique to annual data over the period 1960 to 2008. The results suggest that GDP, electricity prices and an underlying energy demand trend (UEDT) are all important drivers of Turkish electricity demand. The estimated income and price elasticities are found to be 0.17 and -0.11 respectively with the estimated UEDT found to be generally upward sloping (electricity using) but at a generally decreasing rate. Based on the estimated equation, and different forecast assumptions, it is predicted that Turkish aggregate electricity demand will be somewhere between 259 TWh and 368 TWh in 2020.Turkish Turkish Aggregate Electricity Demand; Structural Time Series Model (STSM); Energy Demand Modelling and Future Scenarios.

    Damage states in laminated composite three-point bend specimens: An experimental-analytical correlation study

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    Damage states in laminated composites were studied by considering the model problem of a laminated beam subjected to three-point bending. A combination of experimental and theoretical research techniques was used to correlate the experimental results with the analytical stress distributions. The analytical solution procedure was based on the stress formulation approach of the mathematical theory of elasticity. The solution procedure is capable of calculating the ply-level stresses and beam displacements for any laminated beam of finite length using the generalized plane deformation or plane stress state assumption. Prior to conducting the experimental phase, the results from preliminary analyses were examined. Significant effects in the ply-level stress distributions were seen depending on the fiber orientation, aspect ratio, and whether or not a grouped or interspersed stacking sequence was used. The experimental investigation was conducted to determine the different damage modes in laminated three-point bend specimens. The test matrix consisted of three-point bend specimens of 0 deg unidirectional, cross-ply, and quasi-isotropic stacking sequences. The dependence of the damage initiation loads and ultimate failure loads were studied, and their relation to damage susceptibility and damage tolerance of the mean configuration was discussed. Damage modes were identified by visual inspection of the damaged specimens using an optical microscope. The four fundamental damage mechanisms identified were delaminations, matrix cracking, fiber breakage, and crushing. The correlation study between the experimental results and the analytical results were performed for the midspan deflection, indentation, damage modes, and damage susceptibility

    Volatility in Istanbul Stock Exchange

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    Author's OriginalSince economic agents make the decisions based on the perceived distribution of the random variables in the future, assessment and measurement of the variance has a significant impact on their course of action. Therefore, market participants’ ability to accurately measure and predict the stock market volatility has wide spread implications. This capability has a particular importance in an environment, where the perception of high levels of volatility has the potential to erode the investor confidence and divert the capital inflows from equity markets. This is a particular concern for the emerging equity markets that lack the advanced institutional and informational infrastructures and which are very vulnerable to domestic and foreign capital flows. The purpose of this study is to determine the time-varying characteristics of volatility in an emerging stock market by utilizing rich family of ARCH models. The primary focus of the study is to explore the nature of volatility in the ISE.Aybar, C. B. & Yvan, Z. A. (1998). Volatility in Istanbul Stock Exchange. ISE Review, 6(2)

    Double Inverted Mesiodentes: Report of an Unusual Case

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    This report presents an extremely rare occurrence of two inverted mesiodentes in a child patient. Extraction of both mesiodentes was indicated, owing to the axial rotation of the permanent central incisors caused by these impacted supernumerary teeth. Radiographic evidence of complete healing was observed 24 months following surgical removal of the inverted mesiodentes

    Management of Cervical Root Fracture Using Orthodontic Extrusion and Crown Reattachment: A Case Report

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    Root fractures involve damage to pulp, cementum, dentin, and periodontal ligaments. These injuries affect 0.5% to 7% of permanent teeth. Cervical root fractures are less frequently seen and have a worse prognosis compared with the fractures in the apical or middle third of the root. This case report describes the treatment of a cervical root fracture in a maxillary central incisor. After removal of the coronal fragment, the root was filled temporarily with calcium hydroxide and orthodontic extrusion was initiated. The remaining root portion was elevated above the epithelial attachment and a successful coronal restoration was made using the natural crown of the traumatized tooth

    Tow-Steered Panels With Holes Subjected to Compression or Shear Loads

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    Tailoring composite laminates to vary the fiber orientations within a fiber layer of a laminate to address non-uniform stress states and provide structural advantages such as the alteration of principal load paths has potential application to future low-cost, light-weight structures for commercial transport aircraft. Evaluation of this approach requires the determination of the effectiveness of stiffness tailoring through the use of curvilinear fiber paths in flat panels including the reduction of stress concentrations around the holes and the increase in load carrying capability. Panels were designed through the use of an optimization code using a genetic algorithm and fabricated using a tow-steering approach. Manufacturing limitations, such as the radius of curvature of tows the machine could support, avoidance of wrinkling of fibers and minimization of gaps between fibers were considered in the design process. Variable stiffness tow-steered panels constructed with curvilinear fiber paths were fabricated so that the design methodology could be verified through experimentation. Finite element analysis where each element s stacking sequence was accurately defined is used to verify the behavior predicted based on the design code. Experiments on variable stiffness flat panels with central circular holes were conducted with the panels loaded in axial compression or shear. Tape and tow-steered panels are used to demonstrate the buckling, post-buckling and failure behavior of elastically tailored panels. The experimental results presented establish the buckling performance improvements attainable by elastic tailoring of composite laminates

    Buccal and Palatal Talon Cusps with Pulp Extensions on a Supernumerary Primary Tooth

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    This paper reports an unusual occurrence of talon cusp on a supernumerary primary incisor, presenting on both labial and palatal sides. The tooth was scheduled for extraction due to its interference with the occlusion. Morphometric analysis of the taloned cusps was performed on digitized replicas of the tooth crown using open-source image analysis toolkit (ImageJ). Further non-destructive investigation of the taloned crown under cone-beam X-ray computed tomography revealed pulpal extensions in both talon cusps

    A wetting and drying scheme for ROMS

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    This paper is not subject to U.S. copyright. The definitive version was published in Computers & Geosciences 58 (2013): 54-61, doi:10.1016/j.cageo.2013.05.004.The processes of wetting and drying have many important physical and biological impacts on shallow water systems. Inundation and dewatering effects on coastal mud flats and beaches occur on various time scales ranging from storm surge, periodic rise and fall of the tide, to infragravity wave motions. To correctly simulate these physical processes with a numerical model requires the capability of the computational cells to become inundated and dewatered. In this paper, we describe a method for wetting and drying based on an approach consistent with a cell-face blocking algorithm. The method allows water to always flow into any cell, but prevents outflow from a cell when the total depth in that cell is less than a user defined critical value. We describe the method, the implementation into the three-dimensional Regional Oceanographic Modeling System (ROMS), and exhibit the new capability under three scenarios: an analytical expression for shallow water flows, a dam break test case, and a realistic application to part of a wetland area along the Georgia Coast, USA.We acknowledge support for studies demonstrated in this manuscript that were supported by the National Science Foundation,Division of Industrial Innovation and Partnerships (IIP)under the 3470Z. Defne etal./ Renewable Energy 36(2011)3461e3471 Partnerships for Innovation Program Grant IIP-0332613,and from the Strategic Energy Institute at Georgia Institute of Technology via a Creating Energy Options grant and the 104B Georgia Water Resources Institute Funding Program,and also by the Department of Energy,Wind and Hydropower Technologies Program award number DE-FG36-08GO18174 and by the state of Georgia
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