Abstract-The evolution of the use of electricity in marine vessels is presented and discussed in this article in an historical perspective. The historical account starts with its first commercial use in the form of light bulbs on the SS Columbia in 1880 for illumination, going forward through use in hybrid propulsion systems with steam turbines and diesel engines and then transitioning to the present with the first fully electric marine vessel based entirely on the use of batteries in 2015. Electricity use is discussed not only in the light of its many benefits but also of the challenges introduced after the emergence of the marine vessel electrical power system. The impact of new conversion technologies like power electronics, battery energy storage, and the DC power system on overall energy efficiency, power quality, and emission level is discussed thoroughly. The article guides the reader through this development, the present and future challenges by calling attention to the future research needs and the need to revisit standards that relate to power quality, safety, integrity, and stability of the marine vessel power system, which are strongly impacted by the way electricity is used in the marine vessel.

Abstract-The evolution of the use of electricity in marine vessels is presented and discussed in this article in a historical perspective. The historical account starts with its first commercial use in the form of light bulbs in the SS Columbia in 1880 for illumination purposes, going through the use in hybrid propulsion systems with steam turbines and diesel engines and transitioning to our days with the first case of electric marine vessel entirely based on the use of batteries in 2015. Electricity use is discussed not only in the light of its many benefits but also of the challenges introduced after the emergence of the marine vessel electrical power system. The impact of new conversion technologies like power electronics, battery energy storage and the dc power system on the trajectory of this development is thoroughly discussed. The article guides the reader through the different stages of this development influenced by the different forms electricity took in the marine vessel, with emphasis on how electricity was used has impacted the marine vessel power system development.

Despite extensive research on the bottom-up force of resource availability (e.g., electron donors and acceptors), slow biodegradation rates and stalling at cis-dichloroethene (cDCE) and vinyl chloride continue to be observed in aquifers contaminated with trichloroethene (TCE). The objective of this research was to gauge the impact of the top-down force of protistan predation on TCE biodegradation in laboratory microcosms. When indigenous bacteria from an electron donor-limited TCE-contaminated bedrock aquifer were present, the indigenous protists inhibited reductive dechlorination altogether. The presence of protists during organic carbon-amended conditions caused the bacteria to elongate (length:width, >10:1), but reductive dechlorination was still inhibited. When a commercially available dechlorinating bacterial culture and an organic carbon amendment were added in he presence of protists, the elongated bacteria predominated and reductive dechlorination stalled at cDCE. When protists were removed under organic carbon-amended conditions, reductive dechlorination stalled at cDCE, whereas in the presence organic carbon and bacterial amendments, the total chlorinated ethene concentration decreased, indicating TCE was converted to ethene and/or CO 2 . The data suggested that indigenous protists grazed dechlorinators to extremely low levels, inhibiting dechlorination altogether. Hence, in situ bioremediation/bioaugmentation may not be successful in mineralizing TCE unless the top-down force of protistan predation is inhibited.The bacterially mediated sequential dechlorination of trichloroethene (TCE) to cis-dichloroethene (cDCE), vinyl chloride (VC), ethene, and CO 2 by dehalorespiration is often proposed as the most cost-effective in situ treatment to remediate chlorinated solvent-contaminated aquifers (35,42). TCE mineralization to CO 2 requires specific electron donors (i.e., acetate and H 2 ) typically produced from readily fermentable organic carbon, the presence of specific bacterial species, and sulfate-reducing or methanogenic conditions (1,4,8,15,22,25,33,35,46). When the rate of mineralization is slow or stalled at one of the progeny (cDCE and VC), the problem is usually attributed to the bottom-up force of resource availability (e.g., the absence of a necessary condition such as suitable electron donors or bacterial species) (1,4,10,22,26,43,46). For example, whereas many bacterial species are capable of degrading TCE to cDCE and VC by dehalorespiration (33), only Dehalococcoides ethenogenes is known to convert VC to ethene (25). Hence, if an indigenous population of D. ethenogenes is not present in situ, the system will likely stall at cDCE or VC even if sufficient electron donor is added. Stalling is problematic because VC is more toxic than TCE (18). In this case, bioaugmentation with D. ethenogenes may trigger complete mineralization.An established link exists for the top-down force of predator-prey relationships between protists and bacteria in a range of surface water systems (13,(19)(20)(21)29). Ou...

It's one thing to do the right thing. It's another to be creditable for doing the right thing. Being creditable for doing the right thing requires that one does the right thing out of a morally laudable motive and that there is a non‐accidental fit between those two elements. This paper argues that the two main views of morally creditable action – the Right‐Making Features View and the Rightness Itself View – fail to capture that non‐accidentality constraint: the first because it morally credits agents who make heavy‐duty moral mistakes; the second because it fails to generalise and is too conservative – a point which this paper gives renewed defence. The paper then goes on to defend and develop an alternative according to which moral worth is mediated by the agent's knowing how to respond to the reasons of the type which make acting in that way right. It's argued that this view avoids the problems for the alternatives, and it's shown that in order for the view to avoid collapsing into a problematic form of Reliabilism we'll have to think of states of knowing how as essentially successful in character.