Search results for "Energy engineering"
showing 10 items of 1099 documents
Quadruple-Cation Wide-Bandgap Perovskite Solar Cells with Enhanced Thermal Stability Enabled by Vacuum Deposition.
2022
Vacuum processing of multicomponent perovskites is not straightforward, because the number of precursors is in principle limited by the number of available thermal sources. Herein, we present a process which allows increasing the complexity of the formulation of vacuum-deposited lead halide perovskite films by multisource deposition and premixing both inorganic and organic components. We apply it to the preparation of wide-bandgap CsMAFA triple-cation perovskite solar cells, which are found to be efficient but not thermally stable. With the aim of stabilizing the perovskite phase, we add guanidinium (GA+) to the material formulation and obtained CsMAFAGA quadruple-cation perovskite films wi…
The Potential of a Separated Electric Compound Spark-Ignition Engine for Hybrid Vehicle Application
2022
Abstract In-cylinder expansion of internal combustion engines based on Diesel or Otto cycles cannot be completely brought down to ambient pressure, causing a 20% theoretical energy loss. Several systems have been implemented to recover and use this energy such as turbocharging, turbomechanical and turbo-electrical compounding, or the implementation of Miller cycles. In all these cases however, the amount of energy recovered is limited allowing the engine to reach an overall efficiency incremental improvement between 4% and 9%. Implementing an adequately designed expander–generator unit could efficiently recover the unexpanded exhaust gas energy and improve efficiency. In this work, the appl…
Simultaneous non-invasive gas analysis in artificial photosynthesis reactions using rotational Raman spectroscopy
2022
Optimising reactions in artificial photosynthesis research requires screening of many reaction and operation parameters, which is often resource-intense and time-consuming. In this paper, we demonstrate the use of a rotational Raman-based spectrometer for non-invasive quantification of several gases (H2, O2, N2, CO, CO2) with short analysis times (15 s), enabling high throughput screening. Furthermore, with this device, reaction progress can be monitored in situ, by real-time simultaneous quantification of multiple gases. We have applied this instrument and developed a method to study the O2 dependency of a prototypic light-driven hydrogen evolution reaction, showcasing the value of this ap…
La naturaleza de las naturalezas patrimonializadas. Una aproximación a las formas hegemónicas de representar lo natural
2016
En este artículo examinamos la forma de conceptualizar la naturaleza a través de las áreas protegidas (patrimonialización de la naturaleza). Desde el discurso hegemónico, la naturaleza —susceptible de ser 'patrimonializada'—cumple una serie de requisitos que dibujan en el imaginario lo propiamente natural. Nuestro propósito es analizar cómo, a través de las categorías y las declaraciones efectuadas por los distintos organismos, se configura un prototipo ideal de lo que es la naturaleza. En las declaraciones para la protección de la naturaleza podemos encontrar un discurso tanto expl.cito como implícito de aquello que es leído y protegido como la natural naturaleza. De tal forma que, en los …
Online Meetings in Times of Global Crisis: Toward Sustainable Conferencing
2020
International conferences are an essential component of the timely exchange of ideas and results in the scientific community, where scientists present their results, gain new insights, and meet colleagues and collaborators. In early 2020, a global pandemic caused by a coronavirus (SARS-CoV-2) and the corresponding disease (covid-19) resulted in a number of conferences being canceled or postponed. (1) To foster scientific exchange despite the restrictions, a range of initiatives were launched across the globe to move international conferences online. (2−8) [...]
Sb2S3 solar cells with a cost-effective and dopant- free fluorene-based enamine as a hole transport material
2022
The “Development of Semi-Transparent Bifacial Thin Film Solar Cells for Innovative Applications” benefits from a 999372 € grant from Iceland, Liechtenstein and Norway through the EEA Grants. The aim of the project is to develop a new approach based on novel materials and structures and production technologies, which are the key to further increase the share, and range of applications of PV in areas with sub-average sunlight, including Baltic and Nordic countries. Therefore, development of resource saving, cost-effective and efficient PV devices is a primary challenge of this project. Project contract with the Research Council of Lithuania (LMTLT) No is S-BMT-21-1(LT08-2-LMT-K-01-003). The D…
Methanol fuel processor and PEM fuel cell modeling for mobile application
2010
International audience; The use of hydrocarbon fed fuel cell systems including a fuel processor can be an entry market for this emerging technology avoiding the problem of hydrogen infrastructure. This article presents a 1 kW low temperature PEM fuel cell system with fuel processor, the system is fueled by a mixture of methanol and water that is converted into hydrogen rich gas using a steam reformer. A complete system model including a fluidic fuel processor model containing evaporation, steam reformer, hydrogen filter, combustion, as well as a multi-domain fuel cell model is introduced. Experiments are performed with an IDATECH FCS1200™ fuel cell system. The results of modeling and experi…
Mapping Seasonal Variability of Buildings Electricity Demand profiles in Mediterranean Small Islands
2023
In communities with a high tourist influx and warm climate, such as Mediterranean small islands, the energy demands for space cooling and domestic hot water are expected to significantly increase during summer. Considering the current energy context, for succeeding energy transition and reducing the dependency on not endogenous fossil fuels, it is paramount to increase the deployment of renewable sources of energy, especially wind and solar which, however, are aleatory and unpredictable. Hence, to reduce the high costs for energy supply in these contexts, the analysis of the variation of energy consumption is fundamental. Moreover, mapping the spatial distribution of energy profiles can be …
Separation and identification of petroporphyrins extracted from the oil shales of Tarfaya: geochemical study
2002
Abstract Vanadyl and nickel porphyrins were isolated from the oil shales of Tarfaya (Morocco) by extraction followed by column chromatography. The ratios and characteristics of these porphyrin complexes were essentially obtained on the basis of UV–visible and mass spectrometry data. Geochemical information could be drawn from these data. The nature and the contents of the metals coordinated and non-coordinated to porphyrin systems were also determined in this study.
Catalytic effect of Ca and K on CO2 gasification of spruce wood char
2015
Abstract Gasification is one route to produce chemicals and liquid fuels from biomass. The gasification of the char is catalyzed by alkali and alkaline earth metals in the biomass. In this work the catalytic effect of calcium (Ca) and potassium (K) on CO2 gasification of spruce wood was studied using a thermo gravimetric analyzer (TGA). The ash-forming elements were first removed from the wood using an acid leaching method. Then, various concentrations of K and Ca were absorbed to the wood by ion-exchange to carboxylic and phenolic groups, impregnation of K2CO3 or physically mixing of CaC2O4. The prepared spruce samples were placed in a mesh holder and gasified in the TGA at 850 °C in 100% …