The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This study presents the heat and mass transfer analysis in an unsteady boundary layer flow of a Casson fluid near a stagnation point over a stretching/shrinking sheet in the presence of thermal radiation. For thermal radiation, we consider the linear Rosseland approximation. The effects of binary chemical reaction with Arrhenius activation energy are also considered by taking chemical reaction rate...
This paper illustrates details about the solar radiation distribution on the target of a two-stage solar concentrator that combines the Fresnel lens (FL) and the compound flat concentrator (CFC). The paper starts with a review of some FL development milestones such as the two-stage systems and the comparisons of flat vs. curved lenses in addition to the most noteworthy FL-based solar energy application,...
A new cogeneration system which uses CO2 (carbon dioxide) as a working fluid is proposed and analyzed. The system has high efficiency and no CO2 and other emissions. Thermal energy from a low temperature solar energy collector and the cold of LNG (liquefied natural gas) can be effectively utilized together. The system consists of a subcritical Rankine-like cycle, a solar collector and LNG vaporizing...
Freestanding electrodes with high capacitive performances are designed and constructed for flexible solid-state supercapacitors. Self-supporting electrospun CNFs (carbon nanofibers) networks with high surface areas and good conductivities were used as both internal current collectors and supports for pseudocapacitive materials. Repetitive in situ chemical polymerization of aniline monomers was adopted...
The bulk hydropower transmission with one-fourth of its total capacity in China via UHVDC (ultra-high-voltage direct current) lines brings a new challenge for receiving power grids. There is an urgent need for coordinated operations about the receiving regional power grids which operate outside energy and their own large plants linked in the AC/DC network. A great operating concern is how to shave...
Although Multi-Criteria Decision Making methods have been extensively used in energy planning, their descriptive use has been rarely considered. In this paper, we add an evolutionary description phase as an extension to the AHP (analytic hierarchy process) method that helps policy makers to gain insights into their decision problems. The proposed extension has been implemented in an open-source software...
An unsteady two-dimensional laminar forced convection heat transfer around a square cylinder with the rounded corner edge is numerically investigated for Pr = 0.01–1000 and non-dimensional corner radius, r = 0.50–0.71 at low Reynolds number (Re = 100). The effect of gradual transformation of a square cylinder into a circular cylinder on heat transfer phenomenon is studied. The FVM (finite volume method)...
SPV (solar photovoltaic) systems are often partially shadowed by passing cloud, neighboring building, chimney, tree, telephone pole etc. As a result, their produced power is lower than the expected value despite their size. This reduction in produced power is dependent on area of PVs under shade, shade scenario, module interconnection styles and also on the connection of shaded and non-shaded modules...
This research used an optimization method to highlight the importance of time scales in the design of a bottom-fixed OWC (oscillating water column). The different time scales studied were a sea state, a season, and a year. For the last two scales, a stochastic formulation was used to take into account the random nature of the wave climate in the time interval considered. This paper also describes...
This paper dedicated to investigation the effect of carbons (graphite and carbon fibers), transition metals (TM = Ni, Fe and Al) and oxides (Nb2O5 and V2O5) on Mg–H hydrolysis reaction in aqueous media (3.5 wt% NaCl). Mg – 10 wt% X (X = C, TM and oxides) mixtures were prepared by mechanical milling (1, 3 and 5 h). Mg – 10 wt% G mixtures show the best hydrolysis performance (95% of theoretical hydrogen...
Based on data from 1128 survey questionnaires in western China, this article analyzed the impact of several factors on residential electricity consumption. The results were as follows: (1) ECp (Electricity consumption per capita), PCI (per capita income), diversity of the electrical appliances (AD), purchase price of appliances (APC) and household size (PO) were found to be closely associated. ECp...
This paper presents a high spatial resolution based method for design and operation of a low temperature district heating system and evaluates its feasibility and energy and exergy performance through case comparison. Selected case area is existing district in North Japan. The district heating system design and operation follows a bottom-up approach. The study scope takes into account the demand side,...
Wind energy poses challenges such as the reduction of the wind speed due to wake effect by other turbines. To increase wind farm efficiency, analyzing the parameters which have influence on the wake effect is very important. In this study clustering methods were applied on the wake effects in wind warm to separate district levels of the wake effects. To capture the patterns of the wake effects the...
To improve fuel utilization of HT-PEMFC (high-temperature proton exchange membrane fuel cell), which normally operates under dead-end mode, with properly periodical purging to flush out the accumulated water vapour in the anode flow-field is necessary, otherwise the performance of HT-PEMFC would drop gradually. In this paper, a semi-empirical dynamic voltage model of HT-PEMFC is developed for controller...
Under the trend of global energy prices continuously going up, this paper considers the concept of maximized energy reduction to model the energy productivity index by decomposing it into energy technical change and energy efficiency change. The paper takes the eight SADC (Southern Africa Development Community ) members as an example to estimate their energy efficiency, energy productivity change,...
In the contest of European and National choices regarding energy and mobility policies, the goal of this paper is to introduce reasonable guidelines for the local promotion of electric mobility in an area of central Italy and possibly to extend the methodology to other regions/countries. In fact, the path towards car electrification is started worldwide, but the rate of increase of electrically powered...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.