220 research outputs found
A Comparison on Development of Pumped Storage Hydropower in Europe and Asia. An Analytical Case Study based on Pumped Storage Hydroelectric Projects developed in Europe and Asia in period 2010-2017
No full text"Energy consumption in European countries is increasing in significant amount each year. EU countries are becoming more concerned towards environmental safeguarding along with energy production. Wind and solar power have increased their market in many power systems in the recent decades and the main limitation is that they are greatly time dependent and are not available all the time to cope with variable energy demand. This limitation has led to the concept of a bulk energy storage system-Pumped Storage Hydropower.
Asia holds the largest share of global installed hydropower capacity of 611,063 MW and Europe has total installed hydropower capacity of 218,404 MW. Similarly, the PSH installed capacity of Asia is 67,850 MW and Europe is 50,949 MW. The characteristics of pumped storage hydropower commissioned in the present decade 2010-2017 in Europe and Asia have been compared based on annual addition of PSH capacity in grids, unit cost of construction, mode of use of PSH plants and ownership of PSHs,. Furthermore, the policies undertaken by countries in Europe and Asia are discussed and recommendations for PSH development are made. The results show that there are some measurable differences in development of PSH in Europe and Asia which includes differences in use cases, ownership and policies undertaken for PSH development.
A study of hydro and pumped storage hydropower in Northern Norway
No full text"The role of renewable sources of energy in combating climate change cannot be over-emphasized. Profound measures taken especially by the European Union (EU) in reducing global rising temperatures has seen massive development of renewable sources of energy such as solar and wind. This strategic plan taken by the EU has led to the an increase in national efforts to promote further development of renewable energy systems as well as increased exchange of power between member states due to the challenge of storing energy generated from these sources.
If much energy is going to be produced from these sources, this challenge calls for an increasing need for energy storage to balance power by compensating for the difference between production and consumption. The growing synergy among EU member states has made it possible for Norway to be selected as the “Green Battery” of Europe by developing Pumped Storage Hydropower (PSH) plants as a means of storage technology, the most feasible among all the storage technologies available today. This is achieved by using “surplus” power to pump water to an upper reservoir which can be release back into a lower reservoir to generate power when there is demand.
With the topography of Norway favoring the development of PSH schemes, much research has been carried out especially in Southern Norway and it is estimated that 20 000 MW of power is possible to be generated. This report carries a review specifically on possible sites for the development of PSH in Northern Norway. Results gathered from the screening process in the region shows that a total of 84 pairs of reservoirs can be used, summing up to 19 different potential PSH projects in Northern Norway. The power generation from these PSH projects is estimated to be 25 000 MW. The total cost from an estimated cost analysis reaches to about 526 Million Kroner.
The study further carries out a detailed analysis on the proposed Isvatn-Langvatnet PSH project by running the PSH Model on the chosen reservoir pairs with wind data from the North Sea (in our case). The water level fluctuation used for the reservoirs in the study is 13cm/h for the HRWL and LRWL. Considering factors such as turbine capacity and free reservoir volumes, it is observed that there is 1 hour having no balancing demand with 160 hours also having no actual balancing operation. Number of hours have a balancing demand but no actual operation is 159 hours, this is due to the limitation of shared capacity and limitation of the lower reservoir. The outcome of the simulation process, considers factors which optimizes the mode of the PSH power plant in terms of the economical and its effective operation, which was also used in the hypothesis cost estimation for the PSH projects.
Safe dynamic design of structures.
No full textThe Design of structures under dynamic loading is a demanding subject in safety of engineering design since conventional static failure criteria are unable to deal with
structures under transient loading. This work is a contribution to this significant phenomenon to investigate
the response and failure of structures to pulse loading. An
experimental rig has therefore been designed to achieve the target. A series of experiments has then been carried out to investigate the structural failure under pulse loading using a shock tunnel. A non-linear transient analysis of plates and cylindrical structures under pulse loading has also been performed using ANSYS finite element code in order to
introduce a failure criterion for these specific conditions. A large-scale heat exchanger under pressure pulse loading was also analysed experimentally and numerically. The impulsive load has been chosen to be above the static design
pressure to investigate the effects of impulsive load and
its duration on the plate failure. A critical curve is presented to determine the critical pulse loading and its
duration for structures. The relations between the transient pressure loading, its duration and the natural frequency of
the structure are also explored. It is indicated that the value of the impulsive load on structures may exceed the static design pressure without structural failure. Both experimental work and numerical analyses suggest that the design criteria for structures under dynamic loading are more flexible than those under static loading in which no
freedoms in deviation of any simple yield criterion exist. It is concluded that using a proper failure criterion for any specific problem can increase safe working region of
the structures which leads to economical and safe dynamic design of structures
Dataset for 'Effect of damping on performance of magnetostrictive vibration energy harvester'.
No full textSupporting Matlab M file - Code for modelling of Energy Harvester Access is currently subject to embargo (09/07/23). For more information please contact the corresponding author, Mojtaba Ghodsi
Corrigendum: Confirmatory factor analysis and gender invariance of the Persian version of psychological control scale: association with internalizing and externalizing behavior problems (Frontiers in Psychology, (2023), 14, (1128264), 10.3389/fpsyg.2023.1128264)
No full textCopyright © 2024 Habibi Asgarabad, Salehi Yegaei, Mokhtari, Izalnoo and Trejos-Castillo. cc-byIn the published article, there was an error in the correspondence details. As well as Pardis Salehi Yegaei, Mojtaba Habibi Asgarabad should also be listed as a corresponding author. The complete correspondence details are shown below: *Correspondence: Pardis Salehi Yegaei Mojtaba Habibi Asgarabad The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated
ORIGINAL ARTICLE Strategic Stakeholder Modelofthe Banking System, Mining: Bank SARMAYE Mojtaba Mali; Strategic Stakeholder Modelofthe Banking System, Mining: Bank SARMAYE
No full textABSTRACT Effective organization is an organization meet requires of its environmental components that continuity of organization survival requires to their supports. The Stakeholders analyze is important because it can be have an effective and influential role in the strategic management process of organization. The research problem is the major benefits conflict of the banks strategic stakeholders. The aim of this study is application and its method is descriptive -analytic. The statistical community for the Strategic stakeholders' research is Bank Sarmayeh Iran
Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) – solution in MATLAB®
No full textThis work presents a method for the solution of fundamental governing equations of computational fluid dynamics (CFD) using the Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) in MATLAB®. The fundamental governing equations of fluid mechanics are based on three laws of conservation, referred to as the law of conservation of mass, the law of conservation of momentum and the law of conservation of energy. The continuity equation represents the law of conservation of mass, the Navier-Stokes equations represent the law of conservation of momentum, and the energy equation represents the law of conservation of energy. In SIMPLE, the continuity and Navier-Stokes equations are required to be discretized and solved in a semi-implicit way. This article presents the discretization and method of solution applied to the flow around a 2-D square body. Code is written in MATLAB®. The results show the pressure and velocity fields of the converged solution
Solution of Pure Scattering Radiation Transport Equation (RTE) using Finite Difference Method (FDM) (poster)
No full textRadiative transfer is the physical phenomenon of energy transfer in the form of electromagnetic radiation. The propagation of radiation through a medium is affected by absorption, emission, and scattering. Radiative Transfer Equation (RTE) have been applied in a many subjects including atmospheric science, astrophysics, nuclear, optics, remote sensing, etc. Analytic solutions for RTE exist for simple cases, but, for more realistic media with complex multiple scattering effects, numerical methods are required. In the RTE, six different independent variables define the radiance at any spatial and temporal point. By making appropriate assumptions about the behavior of photons in a scattering medium, the number of independent variables can be reduced. These assumptions lead to the diffusion theory (or diffusion equation) for photon transport. In this work, the diffusive form of RTE is discretized, using a Forward-Time Central-Space (FTCS) Finite Difference Method (FDM). The results reveal the radiance penetration according to Beer-Lambert law
How Do Experts Think? An Investigation of the Barriers to Internationalisation of SMEs in Iran
No full textNowadays, “internationalisation” is a topic of concern for many types of research on small and medium-sized enterprises (SMEs). SMEs pursue internationalization policy as a leading process to keep and improve their position in the competitive business markets. However, SMEs face many challenges that hinder the successful implementation of the internationalization process. This chapter aims to recognise the important barriers to internationalisation for Iranian SMEs. We conduct two studies using a combined exploratory and confirmatory approach. We apply the Delphi method for exploring and forecasting the key barriers in the first study. In the second study, we validate the key indicator employing a Structural Equation Modelling technique for the Confirmatory Factor Analysis of the survey data. In the Delphi method, a group of 24 managers and academic professors in Iran, identified the main barriers. A sample of 210 survey observations was collected from the owner and top managers, senior managers, and employees. The results suggest 8 key factors and 31 indicators of barriers to internationalisation associated with Iranian SMEs: informational, financial, marketing, functional, procedural, governmental, environmental and, tariff and non-tariff. This research contributes to the knowledge of critical obstacles concern for current and future business internationalisation, and the outcomes provide practical implications. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
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