Search results for "efficien"
showing 10 items of 3014 documents
Participation Costs and Inefficiency in Takeover Contests
2010
We consider a takeover in which risk neutral bidders incur private costs to participate to the auction. Supposing that valuations for target firm are common knowledge, we study the optimal strategy of bidders and analyze the takeover result when they get or not toeholds in the target firm. We found that bidder's decision of participation is endogenous. By analyzing bidder's condition of participation, we found that the probability that the potential bidder with the highest valuation will not participate to the control, exists. We show that this probability increases with the size of toeholds possessed by the bidder with low valuation. Nevertheless, the size of toeholds possessed by the bidd…
Sustainable Social Housing in Temperate Areas. Italy and Brazil: the use of vegetation as a retrofit strategy
2014
La tesi si pone come obiettivo l’individuazione di strategie sostenibili per il retrofit del Social Housing in aree a clima temperato, con particolare riferimento all'utilizzo della vegetazione per la riqualificazione degli spazi esterni e per l'incremento delle prestazioni dell'involucro edilizio. La ricerca parte dall’assunto che le regioni del sud Italia e le aree subtropicali del Brasile, accomunati da caratteristiche climatiche affini, si trovano attualmente impegnati nell'identificazione di politiche e soluzioni per la riqualificazione di interi quartieri destinati all'housing sociale, responsabili di elevati consumi energetici e di inadeguate condizioni di comfort abitativo. In quest…
Electrophysical, Magnetoresistivity and Magneto-optical Properties of Multilayer Materials Based on Nanocrystalline and Amorphous Films
2012
In work is presented to the results of complex investigate of phase formation, thermal resistivite, magnetoresistive and magneto-optical properties of multilayers based Fe and Pd, Ag or Ge, which obtained by sequential condensation of the layers with following thermal annealing. Investigation of phase formation processes of thin film systems and established of correlation between this processes and above-mention physical properties. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35009
Long-term stability of phase-separated half-Heusler compounds
2015
Half-Heusler (HH) compounds have shown high figure of merit up to 1.5. Here, we address the long-term stability of n- and p-type HH materials. For this purpose, we investigated HH materials based on the Ti0.3Zr0.35Hf0.35NiSn-system after 500 cycles (1700 h) from 373 to 873 K. Both compounds exhibit a maximum Seebeck coefficient of |α|≈ 210 μV K(-1) and a phase separation into two HH phases. The dendritic microstructure is temperature resistant and upon cycling the changes in the microstructure are so marginal that the low thermal conductivity values (κ4 W m(-1) K(-1)) could be maintained. Our results emphasize that phase-separated HH compounds are suitable low cost materials and can lead to…
Comparative study of modelling the thermal efficiency of a novel straight through evacuated tube collector with MLR, SVR, BP and RBF methods
2021
Abstract Data-based methods are useful for accurate modelling of solar thermal systems. In this work, several artificial neural network (ANN) techniques are proposed to predict the thermal performance of an all-glass straight through evacuated tube solar collector. These are compared to support vector regression analysis. Extensive experimental data sets were collected for training the ANN models. Solar radiation intensity, ambient temperature, wind speed, mass flow rate and collector inlet temperature were selected as the input layer to predict the thermal efficiency of the solar collector. The prediction precision of the ANN models was compared to the multiple linear regression and suppor…
Investigation of flashing phenomena in MSF chambers
2007
The MSF process has covered in the last years more than 50% of world production of desalinated water from the sea. Although this process has been used for several decades, the large energy requirements force to search for new and feasible ways to improve the overall thermal efficiency. Few studies have bee carried out in lab-scale, pilot and industrial MSF units, underlining the complexity of flashing phenomena and the importance of operating parameters settings for optimal performance. In the present work a study on fundamental phenomena occurring inside MSF chambers has been carried out, focusing on the dependence of flashing efficiency on operating parameters and the effects of flashing …
ANALYSIS OF A RECIPROCATE ENGINE–BASED COGENERATION PLANT WITH HIGH TEMPERATURE HEAT RECOVERY FOR INDUSTRIAL USES
2012
In consequence of the increasing awareness on the future scarcity of fossil energy sources and the global warming impact of energy conversion processes, the European Union has been planning several actions to enhance the efficiency of energy use and reduce the environmental impact. The declared goals of EU actions are synthetized in the 20-20-20 formula, consisting of an expected 20% increase of energy efficiency, a 20% contribution to the total energy supply by renewable sources and a 20% abatement of pollutant emissions. Applications of cogeneration in process industry can significantly contribute to achieve these targets. In this paper a reciprocate engine-based Combined Heat and Power (…
An ultrathin suspended hydrophobic porous membrane for high-efficiency water desalination
2017
Abstract An ultrathin highly fluorinated porous membrane was designed for a large production of desalted water at very low energy consumption. Imprinting water droplets were used through a low thermally conductive tetra-fluoroethylene (TFE)/2,2,4-trifluoro-5-tri-fluorometoxy-1,3-dioxol (TIT) (HYFLON AD 60) solution and the generated porous nanofilm was suspended onto a polyethersulfone (PES) honeycomb texture. The very tiny fluorinated thickness together with a large number of small-shaped pores provided the membrane for enhanced anti-wetting surface properties, extremely reduced resistance to water vapor transfer and outstanding thermal efficiency. Fine materials structure-transport relati…
CFD simulation of a membrane distillation module channel
2009
The interest towards the use of membrane distillation (MD) processes for seawater desalination has been rising recently due to the ease of coupling MD with waste and/or solar thermal energy. Notwithstanding the flexibility of the process and its potential for further developments in membrane performances, one of the main drawbacks is the thermal efficiency reduction caused by temperature polarization. Because of such phenomenon, only a small amount of the driving force potentially available for the separation process, i.e. the temperature difference between evaporating and condensing fluids, is actually used for the separation. In order to reduce temperature polarization a study on the effe…
Measurement of the Convective Heat-Transfer Coefficient
2014
We propose an experiment for investigating how objects cool down toward the thermal equilibrium with its surrounding through convection. We describe the time dependence of the temperature difference of the cooling object and the environment with an exponential decay function. By measuring the thermal constant tau, we determine the convective heat-transfer coefficient, which is a characteristic constant of the convection system.