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We characterized the energy transfer pathways in the fucoxanthin-chlorophyll protein (FCP) complex of the diatom Cyclotella meneghiniana by conducting ultrafast transient absorption measurements. This light harvesting antenna has a distinct pigment composition and binds chlorophyll a (Chl-a), fucoxanthin and chlorophyll c (Chl-c) molecules in a 4:4:1 ratio. We find that upon excitation of fucoxanthin to its S2 state, a significant amount of excitation energy is transferred rapidly to Chl-a. The ensuing dynamics illustrate the presence of a complex energy transfer network that also involves energy transfer from the unrelaxed or 'hot' intermediates. Chl-c to Chl-a energy transfer occurs on a timescale of a 100 fs. We observe no significant spectral evolution in the Chl-a region of the spectrum. We have applied global and target analysis to model the measured excited state dynamics and estimate the spectra of the states involved; the energy transfer network is discussed in relation to the pigment organization of the FCP complex.

Organic photovoltaics (OPV) have developed into a vast research area. Progress in various directions has made it difficult to monitor the technology's precise development state. We offer a patent landscape analysis over all OPV devices, their substrates and encapsulation materials to provide an overview of patenting activity from a historical, organizational, geographical and technological point of view. Such an exercise is instrumental for private companies and research institutes aiming at both internal or external technology creation. We discuss our findings in the context of the Industrial Life Cycle model and find OPV still residing in the fluid technology development phase. Technology development is still following an exponential growth path, with the majority of patents coming from the Asian continent and in general private companies. For devices, the main technological focus can be traced back to the " H01L-031" international patent classification (IPC) main group. For the queried substrates, the most attention has gone to glass, but paper and textile have drawn significant interest too. Finally, encapsulation is found to be a less mature research field given the smaller number of patent families. The latter shows that the technology has not matured to the level where processing is carried out on a commercial scale

Abstract Photophysical studies and photovoltaic devices on a low bandgap, high-charge carrier mobility poly(thienylene vinylene) (PTV), prepared from a soluble precursor polymer synthesised via the “dithiocarbamate route”, are reported. In composites with an electron acceptor ([6,6]-phenyl C 61 -butyric acid methyl ester (PCBM), a soluble fullerene derivative), photoinduced absorption characteristic for charged excitations together with photoluminescence quenching are observed indicating photoinduced electron transfer. The “bulk heterojunction” photovoltaic devices using PTV and PCBM composites show short-circuit currents up to 4 mA/cm 2 under AM 1.5 white-light illumination. The photocurrent spectrum of the photovoltaic device shows an onset about 1.65 eV (750 nm), which corresponds to the absorption spectrum of the polymer.

Worldwide, the energy consumption of refrigeration systems increased by 50% in the last 20 years. Currently, active refrigeration systems are often used to maintain cold chains in industry. However, there are remarkable drawbacks in the operation of active systems such as susceptibility to blackouts in the power supply and vibrations during their operation. Therefore, to overcome the aforementioned problems, passive cold chain transport using latent thermal energy storage systems arose as a potential solution. However, these systems require long charging times due to the low thermal conductivity of most phase change materials. In that sense, this paper presents a novel design of a cold storage battery with metal foam enhanced phase change material. The peak efflux of energy and solidification time of the battery is correlated as a function of the inlet temperature and mass flow rate of the heat transfer fluid with a root mean square deviation of 11.4%. The solidification time prediction allows determining the geometry which results in the maximum efflux of energy density for a given energy density. Moreover, the cold battery is placed in an insulated container to analyse its performance during transport. Results show that the tested refrigeration battery can act as a standalone refrigeration system during 15 h. However, improvements in the design of the insulated container are suggested to increase the performance of the system along the discharging cycle.

p-Type Co(3)O(4) nanostructured films are synthesized by a plasma-assisted process and tested in the photocatalytic production of H(2) from water/ethanol solutions under both near-UV and solar irradiation. It is demonstrated that the introduction of fluorine into p-type Co(3)O(4) results in a remarkable performance improvement with respect to the corresponding undoped oxide, highlighting F-doped Co(3)O(4) films as highly promising systems for hydrogen generation. Notably, the obtained yields were among the best ever reported for similar semiconductor-based photocatalytic processes.

Artículos en revistas Electricity production from centralised and decentralised renewable energy resources in Europe is gaining significance, resulting in operational challenges in the electricity system. Although these challenges add to the locational and time dependency of the underlying cost of operating the system, this variability in time and location is not reflected in residential tariff schemes. Consequently, residential users are not incentivised to react to varying system conditions and to help the integration of renewable energy resources. Therefore, this paper provides a theoretical framework for designing a locational dynamic pricing scheme. This can be used to assess existing tariff structures for consumption and injection, and can serve as a theoretical background for developing new tariff schemes. Starting from the underlying costs, this paper shows that the potential for locational dynamic pricing depends on the locational and time dependency of its cost drivers. When converting costs into tariffs, the tariff design should be determined. This includes the advance notice of sending tariffs to users, and the length of price blocks and price patterns. This tariff design should find a balance between tariff principles related to costs, practicality and social acceptability on the one hand, and the resulting demand response incentive on the other. info:eu-repo/semantics/publishedVersion

The emission spectra of CP47-RC and core complexes of Photosystem II (PS II) were measured at different temperatures and excitation wavelengths in order to establish the origin of the emission and the role of the core antenna in the energy transfer and charge separation processes in PS II. Both types of particles reveal strong dependences of spectral shape and yield on temperature. The results indicate that the well-known F-695 emission at 77 K arises from excitations that are trapped on a red-absorbing CP47 chlorophyll, whereas the F-685 nm emission at 77 K arises from excitations that are transferred slowly from 683 nm states in CP47 and CP43 to the RC, where they are trapped by charge separation. We conclude that F-695 at 77 K originates from the low-energy part of the inhomogeneous distribution of the 690 nm absorbing chlorophyll of CP47, while at 4 K the fluorescence originates from the complete distribution of the 690 nm chlorophyll of CP47 and from the low-energy part of the inhomogeneous distribution of one or more CP43 chlorophylls.

Abstract Abuse of market power by dominant generation firms is a growing concern in worldwide electricity markets. This paper argues that relying only on general competition rules—as is the case in most European countries—is insufficient and that complementary ex-ante regulation is needed. In particular, regulators should incentivize firms to sign contracts with retailers by regulating their risk exposure. In a simulation model we show that this type of regulation can significantly reduce the deadweight loss in the market, without imposing large costs on regulatees.