Thermodynamic analysis of the thermal and exergetic performance of a mixed gas-steam aero derivative gas turbine engine for power generation

A thermodynamic analysis is performed for an aero derivative gas turbine engine which utilizes steam injection to increase its efficiency. The target was to explore the performance of a high efficiency gas turbine unit for electric power generation without downstream Rankine cycle. A Rankine cycle for exhaust heat recovery is unattractive because of its large response time and cost of investment. The main purpose of this research was to develop a better understanding of how the optimal cycle efficiency is reached, when the steam for injection is generated by use of the turbine exhaust heat. The STIG cycle becomes attractive for grid stabilization because of its low CAPEX and small footprint and response time. A thermodynamic model has been developed to simulate the simple cycle gas turbine, steam generation and effects of steam injection. Reference input parameters for the model are taken for the GE LM6000 turbine as publicly available. The performance of the engine without steam injection as predicted by the model is compared with literature for validation and compares well. The performance of the STIG cycle as a function of operation parameter steam mass flow and design parameters pressure ratio and turbine inlet temperature is investigated and the optimal parameter settings determined. It is found that this type of cycle shows a very specific parameter setting for optimal efficiency. By using steam injection for the chosen turbine and its parameters an efficiency gain of around 11% points and an output power augmentation of 45% can be achieved.</p

Small-angle X-ray scattering study of the growth kinetics of CuCl nanocrystals in NaCl

The precipitation of CuCl nanocrystals in a NaCl matrix has been studied by time-resolved small-angle X-ray scattering. The experimental results suggest that the nucleation process is accelerated by lattice defects of the matrix remaining in the NaCl lattice after the dissolution of previous nanocrystals at high temperature. The evolution of structural parameters calculated from the scattering curves, such as volume fraction, mean radius and particle number density of the nanocrystals, is discussed in terms of a classical phase separation process but with specific concern for the effect of elastic strains. It was found that Ostwald ripening is effective during the whole period of observation. The effect of elastic strains results in an increase of the critical radius and a decrease of the coarsening rate. The results of the scattering experiments confirm the miscibility gap data determined by exciton spectroscopy

Space charge effects in circular electron beams

In this paper we discuss the effects of the space charge fields of centripetally accelerated particles. It is shown that these effects may cause a discrepancy in terms of the calculated rms emittance as compared to calculations where space charge fields corresponding to a uniform motion of the electrons are used

Fans’ resistance to naming right sponsorships: Why stadium names remain the same for fans

PurposeThe aim of this article is to contribute to the literature by analyzing potential determinants of fan resistance to naming right sponsorships. Although sports sponsorships mostly trigger neutral or positive reactions by fans, the authors find empirical support which provides evidence for fan boycott or resistance.Design/methodology/approachThe authors empirically test a model using a sample of 798 soccer fans and thereby quantify structural relations between determinants and fan resistance. They use a logistic regression to assess potential determinants of fan resistance.FindingsResults indicate that sponsee- and sports-related variables, such as fan/regional identification and attitude toward commercialization, contribute to higher fan resistance. Furthermore, fans see themselves as in-group members who discriminate out-group members. As the sponsoring company takes over control and imposes a “threat” (the change of a stadium’s name) on the group’s ritual place, this results in strong negative emotional reactions. These emotions tend to be repeated and affirmed in intra-group communications which intensify negative reactions unless the sponsor offers a positive contribution from the fans’ standpoints. Our findings confirm that sponsorship fit and perceived benefits of the sponsorship reduce fan resistance while the sponsor’s regional identification is unrelated to fan resistance.Research limitations/implicationsLittle attention has been paid on negative reactions to sponsorships in the existing research. Therefore, future research could assess negative effects resulting from other sponsorship contexts, such as the sale of a club's naming right, promotion campaigns during the venue and to sponsorship deals in general. Moreover, research should be devoted to finding strategies that lead to a reduction of fan resistance to sponsorship actions.Practical implicationsResults show that sponsorship fit reduces fan resistance. Existing literature suggests that sponsorship fit can be improved by emphasis or creation of fit between sponsor and sponsee. Additionally, sponsors should try to build a bridge between sponsor and fans to gain acceptance of the in-group by raising awareness on the benefits that the sponsee receives from their partnership. Moreover, sponsors should actively strive to understand negative reactions of the fans and adapt their communication strategy to avoid resistance, e.g. due to fans’ feelings of overt commercialism.Originality/valueAlthough naming right sponsorships are generally considered a powerful instrument for companies to gain high profile and market share, they seem not to be entirely free of risk. This article contributes to the literature by conceptualizing the phenomenon of fan resistance and assessing the determinants that contribute to fan resistance when naming rights are sold. Our findings extend the understanding of negative sponsorship effects in addition to the mechanisms and theoretical frameworks that are documented in the literature (Cornwell et al., 2005)

CuCl nanocrystals in alkali-halide matrices under hydrostatic pressure

PACS. 64.70.Kb Solid-solid transitions [:AND:] 62.50.+p High-pressure and shock-wave effects in solids and liquids, 78.55.Hx Other solid inorganic materials - 71.35.Cc Intrinsic properties of excitons; optical absorption spectra,