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Graphene coatings, which have many applications in electronics and biomedical, show high performance even when applied at a few nanometers thickness, and have also been applied in solar systems. When graphene is applied to the glass surface of photovoltaic (PV) modules, they result in more energy recovery and lower cleaning service fees due to their features such as high permeability, hydrophobic self-cleaning, and low dust retention. In this study, it was determined how much energy gain and CO2 emission reduction could be achieved as a result of graphene-coating on PV modules compared to standard modules, and if PV modules are applied under Turkish conditions, the investment costs, payback period, and return on investment to the user after the payback period was determined. As a result of the calculations, although the initial investment cost of graphene coating is 0.78 %, more than the standard modules, it is concluded that it offers a lower payback period and high return on investment due to the amount of energy it produces, its ability to self-clean, and low dust retention. [ABSTRACT FROM AUTHOR]

The article is focused on verification of the presumption of poor financial management in companies operating in the building sector. Many authors have written about a financial situation of enterprises in the building sector, especially after the economic crisis in the year 2008, when some of them claim and their results confirm that the main reason of bankruptcy of these companies was not the economic crisis but mainly poor financial management. Our results, which were obtained especially by the method of financial analysis and further by a mathematical and statistical method, support this statement. Within the mathematical and statistical methods, there was return on equity used as an explanatory variable, mainly because all variants of the Altman Z-Score are based on the calculation of ratio indicators, which do not include this type of return. Based on the conducted tests it is possible to state that it is highly desirable for the monitored enterprises in the building industry to reach positive values of return on equity. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to determine the effects of service quality on US airlines’ economic performance. In order to cover this goal, four quality indexes related to the airline industry, and two economic performance indicators, revenues and return on investment (ROI), have been considered. Data from American airline companies from 2006 to 2013 have been used to determine if airlines’ profitability increases when service quality improves. Considering the effects on airlines’ profitability, the results confirm the positive and significant influence of service quality on the ROI of the US airline companies. A non-significant effect was found for airline revenues in relation to quality. No previous research in this area has been done so these findings could encourage airline companies to invest in quality, since this policy can have a positive return on their profitability. [ABSTRACT FROM PUBLISHER]

We examined data on fuel consumption and costs for the years 1950 through 2013, along with economic and population data, to determine the percent of U.S. gross domestic product (GDP) spent each year on fuels, including fossil fuels and nuclear ore, and the growth of the economy. We found that these variables are inversely correlated. This suggests that the availability and cost of energy is a significant determinant of economic performance. We believe this relation is consistent with analyses based on the energy return on investment (EROI) concept in that increasingly scarce, and hence expensive, fuels are a drag on economic growth. The best-fitting linear equation relating the percent of GDP (energy cost share) and year-over-year (YoY) GDP change variables suggests that a threshold exists in the vicinity of 4%; if the percent of GDP spent on fuels is greater than this, poorer economic performance has been likely. Currently, about 5% of GDP is spent on fuels; most of this is for liquids. Continued weak economic performance appears likely unless improvements in energy efficiency, on the order of a factor of 3 for liquid fuels, and/or a more rapid adoption of renewable or nuclear energy sources can be achieved, provided that the EROI of these new sources proves to be sufficiently high. [ABSTRACT FROM AUTHOR]