Energy Transformation System Research Articles

Decomposition analysis of CO<SUB align=right>2 emissions from fuel combustion in selected countries

This article introduces an approach applicable to analysing different factors influencing elements relevant in sustainable development like environmental impacts. The approach is built on the idea of IPAT identity and it applies a chained two-factor decomposition technique for calculating numerical estimates for a larger set of contributing factors than traditionally done in applying decomposition analysis. The empirical example identifies six different meaningful contributing factors or 'driving forces' behind change in carbon dioxide emissions from fuel combustion. The factors include changes in (1) carbon intensity of energy supply, (2) efficiency of the energy transformation system, (3) energy intensity of the national economy, (4) economic growth in terms of labour productivity, (5) share of economically active population and (6) amount of population. The empirical analysis for the years 1990-2003 is carried out for the USA, Japan, China, India, Brazil and the European Union (EU-25) as a whole and for each Member State.

Variable mass energy transformation and storage (VMETS) system using NH3–H2O as working fluid. Part 2: Modeling and simulation under partial storage strategy

Variable mass energy transformation and storage (VMETS) system using NH3–H2O as working fluid. Part 2: Modeling and simulation under partial storage strategy

Variable mass energy transformation and storage (VMETS) system using NH3–H2O as working fluid, Part 1: Modeling and simulation under full storage strategy

Abstract This paper presents a new variable mass energy transformation and storage (VMETS) system using ammonia–water solution (NH3–H2O) as working fluid. The system has a wide range of working temperature. It can be used to shift load with a diurnal energy storage system for cooling in summer, heating in winter, or hot water supplying all year long. It can also be used to store refrigerating energy for various industrial and commercial applications. The key to the system is to regulate the chemical potential by controlling the refrigerant mass fraction in the working fluid with respect to time. As a result, by using a solution storage tank and an ammonia storage tank, the energy transformation and storage can be performed at the desirable time to provide low cost cooling and heating efficiently. As the first part of our study, this paper presents the principle and dynamic models of the VMETS system and performs the numerical simulation when the system works in the cooling and heating modes, respectively, under the full storage strategy. The simulation predicts the dynamic behavior of the VMETS system under various operation conditions and shows that the VMETS system for cooling in summer is also suitable for heating in winter or for hot water supplying all year long by adjusting the initial solution concentration. The energy conversion efficiency of the system is larger than that of conventional thermal energy storage (TES) systems, especially under the condition of system operation for heating or hot water supplying in the heating mode. These simulation results are very helpful for detailed design and control of the system. To investigate the system performance under the partial storage strategy, modeling and numerical simulation will be performed in a subsequent paper.

Investigation of excited-state proton transfer in 2-naphthol derivatives containing a carboxyl group in organic solvents and in methanol–water mixtures

Excited-state proton transfer (ESPT) in 2-naphthol derivatives with electron withdrawing substituent (SO 2NH) dissolved in methanol and methanol–water mixtures is investigated. The analogs studied contain also a carboxyl group, situated at various distances from the proton donating phenolic group. The method of investigation consists in measuring the steady state fluorescence spectra. The parameter R of these spectra (ratio of fluorescence quantum yields at two defined wavelengths) given by Weller’s equation was fitted to the experimental values of R as a function of water concentration in the mixtures. From this procedure, ESPT rate constant and other parameters of this reaction were obtained. It was found that the carboxyl group contained in the molecule of 2-naphthol derivative greatly enhances ESPT reaction in methanol. This effect depends on the flexibility of a chain linking the aromatic system with the carboxyl group. ESPT reaction in five various analogs of 2-naphthol with an electron withdrawing substituent and a carboxyl group was compared. Influence of water addition and the fluorophore concentration, on ESPT was studied in detail. The effect of organic acid addition to the methanolic solution was also investigated. Influence of other organic solvents on ESPT is compared to that of methanol. Our results indicate that proton transfer to the carboxyl group and a preferential binding of other polar molecules play an essential role in the kinetics of proton transfer reaction The role of these catalytic effects is more pronounced in low polar media than in water solutions. By analogy to our model systems, conclusions concerning the proton transfer reaction in biological energy transformation systems can be drawn.

Study on Growth Mechanism of Self-Induced Sloshing, Using Numerical Simulation. 2nd Report. Oscillation Energy Transformation System.

A self-induced sloshing is excited by the flow itself without any other external force. In a rectangular tank having a horizontal plane jet, the 1st mode sloshing grew in a certain condition of the inlet velocity and the water level. The self-induced sloshing in the rectangular tank was simulated, using a two-dimensional numerical simulation code. The simulated results agreed qualitatively with the experimental ones. In this study, a growth mechanism of self-induced sloshing in the numerical simulation was evaluated. The interaction between the free surface motion and the unsteady flow was modeled simply. The oscillation energy (En) supplied for sloshing motion was calculated from the pressure and velocity distributions in the tank. The oscillation growth was related to the sign, magnitude and distribution of supplied oscillation energy (En). Therefore, the excitation of the simulated self-induced sloshing was quantitatively explained by the present mechanism. The self-induced sloshing was considered to be caused by the nonlinear interaction between the jet and the sloshing motion without inlet-outlet flow. It was clarified that the excitation of self-induced sloshing was dependent on the distribution of the oscillation energy along the jet.

P-E3-22 Dynamics of the states of energy transformation systems in chloroplasts: N.V.Budagovskaya. Institute of Plant physiology of the Russian Academy of Sciences, Moscow, (Russia)

P-E3-22 Dynamics of the states of energy transformation systems in chloroplasts: N.V.Budagovskaya. Institute of Plant physiology of the Russian Academy of Sciences, Moscow, (Russia)

The natural gas-absorption method system as an alternative to the electric power-mechanical compression system in Spain

In any energy transformation system, thermodynamical, ecological and economic factors must be considered. However, any one of these, taken separately, is insufficient to make a final decision on the feasibility of substituting one system for another. Our study is focused on finding an analytical framework which might serve as a decision-making instrument for the profitability of absorption-compression systems fed by natural gas (ACNG). To do this, it is necessary to estimate the replacement capacity of these over mechanical compression systems fed by electric power (MCEP), and under what circumstances the probabilities of operational success or failure can be foreseen. The advantages inherent in ACNG systems in Spain are the low cost of natural gas and the uninterrupted use of this fuel, which can be used for both heating and cooling of buildings. Their main handicap is based on the supposition of an insurmountable difference between the energy efficiency of absorption cycles and mechanical compression. However, bearing in mind the conversion efficiency of one cycle or the other from the primary energy source (natural gas to heat and to electricity, respectively), the actual efficiencies of complete transformation from fuel to cold are not all that different. Lithium bromide absorption water condensated COP e = 0.56 Alternative mechanical compression water condensated COP e = 0.96 Centrifugal mechanical compression water condensated COP e = 1.2. From an ecological point of view, in addition to the substitution of R11 with R123, it is necessary to evaluate the effective destructive potential of R22 on the ozone layer and its impact on the greenhouse effect. While the two R22 indexes reflect an improved performance with respect to R11, the effective incidence is hidden. The working pressure of the refrigerant, higher for R22, can compensate for the greater number of chlorine atoms in R11 molecules. In the economic domain, ACNGs can be relatively competitive systems in Spain in comparison to MCEPs. The COP e of mechanical compression, the price of an electric kWh and the difference in initial investments between ACNG systems and MCEP systems are shown in our study as the three most decisive variables in determining the profitability of the former over the latter.

A device to extract energy from water waves

In recent years attention has been focused on means of extracting energy from ocean waves. As a result, a number of systems have been devised by means of which wave energy, which consists of potential and kinetic fluid energy, can be captured and transformed into either mechanical, hydraulic or electrical energy. The majority of the systems transform the wave motion into a reciprocating motion of a mechanical system which in turn drives some other form of energy transformation system finally yielding electric or hydraulic energy. The selection of a reciprocating system to transform wave motion into mechanical motion is an obvious choice when the waves are interpreted in terms of being a free-surface phenomenon. It can be shown however, that it is possible to transform wave energy directly into rotational mechanical energy based on a different viewpoint of wave motion. In this paper the fundamental characteristics of such device are discussed and a mathematical model developed at the Delft University of Technology describing the properties of the device will be verified by means of results of model tests carried out at the Maritime Research Institute Netherlands.

Nitrite reduction to nitrous oxide by propionibacteria: Detoxication mechanism

Characteristics of dissimilatory nitrate reduction by Propionibacterium acidi-propionici, P. freudenreichii, P. jensenii, P. shermanii and P. thoenii were studied. All strains reduced nitrate to nitrite and further to N2O. Recovery of added nitrite-N as N2O-N approached 100%, so that no other end product existed in a significant quantity. Specific rates of N2O production were 3 to 6 orders of magnitude lower than specific rates of N2 production by common denitrifiers. Oxygen but not acetylene inhibited N2O production in P. acidi-propionici and P. thoenii. Nitrite reduction rates were generally higher than nitrate reduction rates. The enzymes involved in nitrate and nitrite reduction were either constitutive or derepressed by anacrobiosis. Nitrate stimulated synthesis of nitrate reductase in P. acidi-propionici. Specific growth rates and growth yields were increased by nitrate. At 10 mM, nitrite was toxic to all strains, and at 1 mM its effect ranged from none to total inhibition. No distinction was obvious between incomplete forms of denitrification and dissimilatory nitrate reduction to ammonia. N2O production from nitrite by propionibacteria may represent a detoxication mechanism rather than a part of an energy transformation system.

An Ecological Approach to Study of the Family

An ecological approach for examination of the interdependnece of family and its interacting environments is presented. Attention is given to the function the family plays as an energy transformation system, with particular emphasis on its role in the production of human capital through the building of family and individual competences. These competences are essential for families and individuals to cope with crises and problems on many levels: individual, family, community and societal. Use of an ecological approach can enhance the understanding of the relationship of behavior to environmental conditions and the effects on families of the institutions and the organizations with which they interact. This approach can also provide a framework for design and implementation of imaginative intervention programs and support systems based on knowledge of family/environment interaction.

Zum Prinzip der Photophosphorylierung und oxidativen Phosphorylierung

The energy transformation systems of Halobacterium halobium, Vibrio succinogenes, chloroplasts and mitochondria are described on the basis of the chemiosmotic theory. Nature seems to utilize three quite different mechanisms for electrogenic proton transport. Structure and function of the ATP-synthetase complexes, however, seem to be quite similar in the various energy-conserving systems.

Evolution In The Training Of RNN Marine Engineer Officers

The introduction of the information age brought about considerable changes in the professional world of the Marine Engineer Officer RNN. The traditional training program entailed a combination of military subjects, general education and technical subjects. Naturally a seagoing practical training period was the final integrating exercise. The introduction of the computer in its various shapes created a totally different automated world, where knowledge based systems assist in controlling complex energy converting machines, where information is widely and readily available and where the intellectual technical work more and more is carried out ashore. The marine engineer is confronted with complex systems, dominated by management problems related to the operation of ships. He has to change from technical problem solver to technical manager. The new curriculum presents, based on fundamental knowledge and understanding of mathematical and scientific subjects, systems science, economics, logistics, human resource management, energy transformation systems, operational research and a management based practical training period at sea. Naturally the military subjects and the general education have been preserved, but in a modernised way. The complete training programme takes nominally 5 years. The first 3 years are presented in the Naval College. The 4th year is divided in a half year seagoing training period and a half year technical management at the Naval College. The 5th and final year is a combined Naval College and University of Technology programme. Students graduate (bachelor level) in one of the following subjects: Platformsystems, Maintenance Engineering, Maritime Electrical Energy Systems, Production Operational Management and Maritime Materials Engineering. The modern marine engineer in the RNN will be a Scientific Educated Operational Manager of Technical Systems. He will also have the intellectual base to find his way in the maze of the uncertainties of the future. Transactions on the Built Environment vol 11, © 1995 WIT Press, www.witpress.com, ISSN 1743-3509 820 Marine Technology and Transportation