Search results for "Fuel Technology"
showing 10 items of 323 documents
Organics versus clastics: conditions necessary for peat (coal) development
1990
Abstract The absence or lack of detrital influx into ancient peat-forming swamps is critical to the formation of low-ash coal. Modern and ancient coal-forming swamps of continental basins show a separation of peat and clastic sediments which is partially fault controlled. In the African rift valleys as well as in the Stephanian intermontane coal basins of France, thick peat free from clastic input may be the result of tectonic activity. In the paralic basins of Morocco (Westphalian B) and Nigeria (Late Cretaceous) coal occur landward of the shoreline turnaround and are related to a relative high stand of the sea, which curtailed detrital influx into the basins. Thus, peat formation occurred…
Origin of the Enhanced Photoluminescence Quantum Yield in MAPbBr 3 Perovskite with Reduced Crystal Size
2018
Methylammonium lead bromide perovskite (MAPbBr3) has been widely investigated for applications in visible perovskite light-emitting diodes (LEDs). Fine-tuning of the morphology and of the crystal size, from the microscale down to the quantum confinement regime, has been used to increase the photoluminescence quantum yield (PLQY). However, the physical processes underlying the PL emission of this perovskite remain unclear. Here, we elucidate the origin of the PL emission of polycrystalline MAPbBr3 thin films by different spectroscopic techniques. We estimate the exciton binding energy, the reduced exciton effective mass, and the trap density. Moreover, we confirm the coexistence of free carr…
Controlling the Phase Segregation in Mixed Halide Perovskites through Nanocrystal Size
2019
Mixed halide perovskites are one of the promising candidates in developing solar cells and light-emitting diodes (LEDs), among other applications, because of their tunable optical properties. Nonetheless, photoinduced phase segregation, by formation of segregated Br-rich and I-rich domains, limits the overall applicability. We tracked the phase segregation with increasing crystalline size of CsPbBr3–xIx and their photoluminescence under continuous-wave laser irradiation (405 nm, 10 mW cm–2) and observed the occurrence of the phase segregation from the threshold size of 46 ± 7 nm. These results have an outstanding agreement with the diffusion length (45.8 nm) calculated also experimentally f…
Identification of indigoid compounds present in archaeological Maya blue by pyrolysis-silylation-gas chromatography–mass spectrometry
2014
Abstract A study based on the use of pyrolysis-silylation-gas chromatograpy–mass spectrometry (Py-GC–MS), which aimed to identify indigoid compounds and to clarify the multicomponent composition of Maya blue (MB) pigment, has been carried out. A series of reference compounds and synthetic MB specimens prepared in the laboratory have been analysed by this technique. An analysis of archaeological MB samples from 14 Maya archaeological sites from Mexico and Guatemala has also been performed. The obtained results demonstrate that, in addition to indigo, oxidised species such as dehydroindigo, which is formed as a result of redox processes taking place while preparing the pigment, are present in…
The structure of western Sicily, central Mediterranean
2002
Western Sicily is part of the Sicilian chain, a sector of the SE-verging Alpine orogenic belt in the central Mediterranean. Interpretation of seismic reflection profiles, boreholes and recent inland geological data, have enabled us to assess the deep structural grain. A wedge of flat-lying Mesozoic–Miocene carbonate and terrigenous rocks (pre-Panormide nappes) is superimposed on NW-trending, 7–8 km thick, Mesozoic–Paleogene carbonate thrust ramps (Trapanese units), arranged in two structural levels extending from the Tyrrhenian coast to western offshore Sicily. Upper Miocene to Pleistocene terrigenous strata, often deformed, fill syntectonic basins above the thrust pile. The main tectonic t…
Removal of ethyl acetate, n-hexane and toluene from waste air in a membrane bioreactor under continuous and intermittent feeding conditions
2012
BACKGROUND: European Union environmental policy has focused on abatement of volatile organic compounds (VOCs) from industrial emissions, and new European VOC emission limits have been established. This study analyzes the performance of a composite membrane bioreactor treating air stream contaminated with ethyl acetate, n-hexane and toluene under continuous and intermittent feeding conditions. RESULTS: The system was operated under continuous feeding conditions: removal efficiencies (REs) higher than 99% were obtained for inlet loads up to 200 g m−3 h−1 and empty bed residence times (EBRTs) as short as 15 s for ethyl acetate. A maximum elimination capacity of 75 g m−3 h−1 (RE ∼66%) at an EBR…
Electrodeposited nickel–zinc alloy nanostructured electrodes for alkaline electrolyzer
2022
Abstract Over the last decade, as a consequence of the global decarbonization process, the interest towards green hydrogen production has drastically increased. In particular a substantial research effort has focused on the efficient and affordable production of carbon-free hydrogen production processes. In this context, the development of more efficient electrolyzers with low-cost electrode/electrocatalyst materials can play a key role. This work, investigates the fabrication of electrodes of nickel-zinc alloys with nanowires morphology cathode for alkaline electrolyzers. Electrodes are obtained by the simple method of template electrosynthesis that is also inexpensive and easily scalable.…
Power dispatching techniques as a finite state machine for a standalone photovoltaic system with a hybrid energy storage
2020
Standalone photovoltaic system (SPVS) is usually embedded with an energy storage unit to overcome the intermittency of photovoltaic (PV) generation as well as to address load variations in off-grid operation. In SPVS energy systems, batteries can serve as the long term energy storage and contributing to the large portion of the energy demand but to overcome the load intermittency, it necessitates a fast response energy storage embedded with the battery as a hybrid energy storage (HES) for dynamic loads (e.g., Electric Vehicle loads, emergency power management). In this work, Lead-Acid (LA) battery and supper capacitor (SC) array are used as the HES. HES helps not only in increasing more uti…
A review of fuel cell based hybrid power supply architectures and algorithms for household appliances
2014
Abstract Nowadays, renewable power system solutions are widely investigated for residential applications. Grid-connected systems including energy storage elements are designed. Advanced research is actually focused on improving the reliability and energy density of renewable systems reducing the whole utility cost. Source and load modeling, power architectures and algorithms are only a few topics to be addressed. Designers have to carefully deal with each subtopic prior to design efficient renewable energy systems. In the literature, each topic is separately discussed and the lack of a unique reference guide is clear to power electronics designers. In this paper, each design step including …
Hydrogen and methane yields of untreated, water-extracted and acid (HCl) treated maize in one- and two-stage batch assays
2011
Abstract In the present study, two-stage H 2 and CH 4 production was compared with one-stage CH 4 production from maize subjected to water extraction and acid (HCl) treatment. In addition, the effect of duration (2 and 14 days) of the first-stage H 2 process on the H 2 yields and subsequent CH 4 yields from the second-stage was also investigated. Results showed that the average H 2 yields from untreated maize were 5.6 and 9.9 ml/g volatile solids added (VS added ) after 2 and 14 days, respectively. On the other hand, H 2 yields from water-extracted and HCl-treated maize were 18.0 and 20.5 ml/gVS added (14 d), respectively. On comparison to one-stage CH 4 assays, the average increase in CH 4…