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Co-deposition of carbon atoms with hydrogen isotopes and hydrogenated carbon radicals and molecules is recognized as the main mechanism for tritium retention in the graphite walls of the previous tokamak fusion devices. Significant tritium retention would be a serious concern for safe and economic long-term operation of future fusion test reactors and fusion energy systems. Similar deposits are observed on the surface of the engineered components in a tritium-producing assembly, known as a Tritium-Producing Burnable Absorber Rod (TPBAR). Characterization of the deposits can help understand the tritium transport, accumulation history and distribution in TPBARs. This study reports our recent results from the carbonaceous deposits formed on an aluminide-coated cladding in the lower plenum of a TPBAR following thermal neutron irradiation. The observed deposits are amorphous in nature, consisting of flakes of interconnected nanoscale features. They contain primarily double-bonded carbon (e.g., alkene) and carbonyl carbon, as well as a minor fraction of aliphatic carbon, all of which are likely tritiated. A similar co-deposition process that occurred in previous fusion devices is responsible for the formation and growth of the carbonaceous deposits.

Abstract An alkaline earth boro-aluminosilicate glass (Eagle XG), a soda-lime glass, and a light-weight polyethylene-terephthalate (PET) foil, used as typical substrates for photovoltaics, were treated by an energetic proton beam (3 MeV, dose 106–107 Gy) corresponding to approx. 30 years of operation at low Earth orbit. Properties of the irradiated substrates were characterized by atomic force microscopy, optical absorption, optical diffuse reflectance, Raman spectroscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and terahertz (THz) spectroscopy. Minimal changes of optical and morphological properties are detected on the bare Eagle XG glass, whereas the bare PET foil exhibits pronounced increase in optical absorption, generation of photoluminescence, as well as mechanical bending. On the other hand, the identical substrates coated with Indium-tin-oxide (ITO), which is a typical material for transparent electrodes in photovoltaics, exhibit significantly higher resistance to the modifications by protons while ITO structural and electronic properties remain unchanged. The experimental results are discussed considering a potential application of these materials for missions in space.

Abstract Many organizations in the world are interested in waste management problems and their potential solutions. In order to solve these problems, a Japanese venture company has developed an innovative thermal decomposer for organic wastes called ERCM (Earth-Resource-Ceramic-Machine). The ERCM reactor employs electron injected air to promote the thermal decomposition reaction, while the effect of electron injection into air has not yet been clarified. An experimental work was performed using a fixed bed reactor to explore the effects of different parameters of electron injection into air, the reaction temperature and different feedstock on the syngas generation. The main purpose of this study is to clarify the phenomena occurring in the ERCM reactor where a direct current electric field is produced in the flame reaction zone to enhance the thermal decomposition of wastes. In this regard, a mathematical model for simulating the thermal decomposition of solid waste in the presence of an electric field have been developed. The equations of aero-thermochemistry are coupled to the balance equations for densities of charged species, and the Poisson equation for the electrical potential is solved. The model was validated by the experimental data and showed a good agreement. The results showed that the electric field significantly improves the stabilization of the flame. From the release behavior of CO and CO2, it is noted that the electron injection would affect the char combustion process significantly. Finally the effect of the flame reaction zone generated by the field induced ion wind on the thermal decomposition was investigated.

Correction for ‘Mesoporous thin film WO3 photoanode for photoelectrochemical water splitting: a sol–gel dip coating approach’ by Samantha Hilliard et al., Sustainable Energy Fuels, 2017, 1, 145–153.

AbstractCosmic Ray Albedo Neutron Decay (CRAND) has been recently confirmed as a source of energetic electrons at the inner edge of the inner belt by the Colorado Student Space Weather Experiment (CSSWE) mission. Here we use observations from the Detection of Electro‐Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) mission, to investigate the CRAND contribution to inner belt electrons quantitatively over a broad energy range (~100–800 keV). Spectral fitting analysis supports the conclusion that CRAND is the most important electron source at the inner edge of the inner belt. For the first time, we show that CRAND is the dominant source of >250‐keV quasitrapped electrons throughout the inner belt and slot region during quiet times. We suggest that additional sources for <250‐keV electrons exist, perhaps from inward transport. In contrast, dynamics of electrons in the inner belt and slot region is dominated by injections during active times.

Costs to permit Marine Energy projects are poorly understood. In this paper we examine environmental compliance and permitting costs for 19 projects in the U.S., covering the last 2 decades. Guided discussions were conducted with developers over a 3-year period to obtain historical and ongoing project cost data relative to environmental studies (e.g., baseline or pre-project site characterization as well as post-installation effects monitoring), stakeholder outreach, and mitigation, as well as qualitative experience of the permitting process. Data are organized in categories of technology type, permitted capacity, pre- and post-installation, geographic location, and funding types. We also compare our findings with earlier logic models created for the Department of Energy (i.e., Reference Models). Environmental studies most commonly performed were for Fish and Fisheries, Noise, Marine Habitat/Benthic Studies and Marine Mammals. Studies for tidal projects were more expensive than those performed for wave projects and the range of reported project costs tended to be wider than ranges predicted by logic models. For eight projects reporting full project costs, from project start to FERC or USACE permit, the average amount for environmental permitting compliance was 14.6%.

Uncertainty surrounding the potential environmental impacts of marine energy (ME) has resulted in extensive and expensive environmental monitoring requirements for ME deployments. Recently, there have been more ME deployments and associated environmental data collection efforts, but no standardized methodologies for data collection. This hinders the use of previously collected data to inform new ME project permitting efforts. Triton Field Trials (TFiT), created at the Pacific Northwest National Laboratory by the United States (U.S.) Department of Energy, explores ways to promote more consistent environmental data collection and enable data transferability across ME device types and locations. Documents from 118 previous ME projects or ME-related research studies in the U.S. and internationally were reviewed to identify the highest priority stressor–receptor relationships to be investigated and the technologies and methodologies used to address them. Thirteen potential field sites were assessed to determine suitable locations for testing the performance of relevant monitoring technologies. This introductory paper provides an overview of how priority research areas and associated promising technologies were identified as well as how testing locations were identified for TFiT activities. Through these scoping efforts, TFiT focused on four activity areas: collision risk, underwater noise, electromagnetic fields, and changes in habitat. Technologies and methodologies were tested at field sites in Alaska, Washington, California, and New Hampshire. Detailed information on the effectiveness of the identified methodologies and specific recommendations for each of the four focus areas are included in the companion papers in this Special Issue.

Abstract Buoys carrying scientific equipment usually need continuous power supply for the operation of these equipments. These buoys can be equipped with actuators and controlled to harvest power from the heaving motion of the buoy. A two-body wave energy converter can be designed such that the buoy heaves to harvest energy while the second (lower) body carries the science equipments. This paper presents a control approach for this type of two-body wave energy converter. This control approach is a multi resonant control that attempts to maximize the harvested energy from the buoy (upper body). In this model, the actuator is attached to both bodies. The lower body however is required to have minimal heave motion. The proposed multi resonant control utilizes measurements of the buoy position. The frequencies of the measured buoy position are estimated, along with the motion amplitudes of these frequencies, and used for feedback control. Estimation is carried out using two approaches; the first uses a linear Kalman filter while the second uses an extended Kalman filter. A new method for handling the motion and actuation limitations, suitable for the multi resonant control, is proposed. Various numerical simulation results are presented in the paper. Simulation results show that the linear Kalman filter estimation approach is more robust and computationally efficient compared to the extended Kalman filter.