hermally induced decomposition of hard and soft amorphous hydrocarbon films was investigated by thermal effusion spectroscopy. Released species were detected by a sensitive quadrupole mass spectrometer using two different experimental setups for thermal effusion. Species released in a molecular beam setup were detected in direct line of sight to the sample surface, while species released in a remote UHV oven had no direct line of sight to the mass spectrometer. Soft, hydrogen-rich carbon films exhibit a desorption maximum at T≈740 K while hard films with a low hydrogen content have their maximum at T≈870 K. Additionally, the spectrum of released species differs dramatically between hard and soft films. We found a significant redeposition of species released from soft films. From the redeposited fraction of material we estimated an average redeposition probability of about 50% for species released from soft films.
A large number of offshore wind farms and interconnectors are expected to be constructed in the North Sea region over the coming decades, creating substantial opportunities for the deployment of integrated network solutions. Creating interconnected offshore grids that combine cross-border links and connections of offshore plants to shore offers multiple economic and environmental advantages for Europe's energy system. However, despite the growing consensus among key stakeholders that integrated solutions can be more beneficial than traditional radial connection practices, no such projects have been deployed yet. In this paper we quantify costs and benefits of integrated projects and investigate to which extent the cost-benefit sharing mechanism between participating countries can impede or encourage the development of integrated projects. Three concrete interconnection case studies in the North Sea area are analyzed in detail using a national-level power system model. Model outputs are used to compute the net benefit of all involved stakeholders under different allocation schemes. Given the asymmetric distribution of costs and benefits, we recommend to consistently apply the Positive Net Benefit Differential mechanism as a starting point for negotiations on the financial closure of investments in integrated offshore infrastructure.
In this paper, we analyse the occurrence of negative electricity prices on the German day-ahead spot market for the years 2008 and 2009. An empirical analysis shows that either a low system load combined with a moderate wind generation or a moderate system load combined with a high wind generation is a neccessary condition for the appearence of negative prices. However, the linear correlation between the negative market prices and global variables that characterise the system status (system load, wind generation, net export, residual load) is relatively low - wind generation having the highest correlation (-0.42). By elaborating the actual volumes of renewable electricity that are traded on the spot market, a marginally better correlation can be achieved. Limited transparency in this field makes this type of market-oriented analysis difficult. We also find that the negative spot market prices cause higher capacity prices in the negative minute reserve market. The influence on the secondary reserve is less definite because of the long contracting periods in this market
The removal of redeposited layers from tile gap structures with ITER-like geometries was investigated with various lowtemperature glow discharges in oxygen. The test structure consists of 19 mm deep gaps with widths ranging from 0.5 to 4 mm. Erosion rates inside the gaps are reduced compared with a directly exposed witness surface. Smallest erosion is found for the lowest particle energies. Erosion at the bottom of the gap increases linearly with the gap width. Erosion on the side walls drops nearly exponentially with increasing distance from the top. Side wall erosion dominates the total eroded amount for all cases investigated. The total eroded amount integrated over the whole inner gap surface is larger than the amount that would be eroded on a flat surface with an area identical to the gap opening.
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