• Energy Research
• Embargo close
• ES close
• EU close
• DK close

These 285 documents have been used for the three sections that are part of the results of this article (documents statistics, bibliometric analysis, and literature review statistics). For this purpose, it was necessary to carry out an exhaustive review of the 285 selected documents and to complement this information with the data provided by Scopus. The data-charting process was as follows: the four researchers agreed on the types of data to be extracted, two of them carried out the review while the other two supervised. If any type of data worthy of investigation emerged during the reading, it was discussed, and if appropriate, included, making it an iterative process. For each of the documents, the following variables were collected in a table: author/s, title of the document, year of publication, journal in which it was published, type of document (article or review), number of citations and citations per year, relevance (weighting given by Scopus), DOI, geographical location of researchers, abstract, author keywords and keywords suggested by Scopus, JIF, JCI and H-index information of the journal in which the document is published (with quartiles and percentiles), subject area categories provided by Scopus, territory studied, renewable energy source studied, research technique or methodology used, primary data source used and years collected. In addition, for articles using quantitative techniques, all variables included in each model have been collected.

The phenomenon of global change is prompting the implementation of measures aimed at mitigating various effects, with humans being primarily impacted. The objective of this investigation is to analyse the potential self-sufficiency in the built environment through the utilisation of energy generated by photovoltaic systems. These systems have the capacity to reduce or even eliminate the reliance on grid electricity and non-renewable energy sources. The study commences with the delineation of eight neighbourhoods within the city of Madrid, Spain, each characterised by a distinct building typology. In order to ascertain the degree of self-sufficiency, this study calculates the energy production from solar photovoltaic systems installed on rooftops, and then proceeds to assess the energy consumption of each building. The results of the analysis demonstrate the capacity of photovoltaic installations to meet the electricity demands of buildings, such as single-family houses, almost completely, and partially in others, such as multi-family dwellings with multiple units per floor. Furthermore, the impact of differences in building height and urban context on self-sufficiency potential is explored.

This perspective covers the use of molybdenum disulfide and related compounds, generally termed MoSx, as electro- or photoelectrocatalysts for the hydrogen evolution reaction (HER). State of the art solutions as well as the most illustrative results from the extensive electro- and photoelectrocatalytic literature are given. The research strategies currently employed in the field are outlined and future challenges pointed out. We suggest that the key to optimising the HER activity of MoS2 is divided into (1) increasing the catalytic activity of the active site, (2) increasing the number of active sites of the catalyst, and (3) improving the electrical contact to these sites. These postulations are substantiated by examples from the existing literature and some new results. To demonstrate the electrocatalytic properties of a highly conductive MoS2 hybrid material, we present the HER activity data for multi-wall MoS2 nanotubes on multi-wall carbon nanotubes (MWMoS2@MWCNTs). This exemplifies the typical data collected for the electrochemical HER. In addition, it demonstrates that the origin of the activity is closely related to the amount of edges in the layered MoS2. The photoelectrocatalytic HER is also discussed, based on examples from literature, with an emphasis on the use of MoSx as either (1) the co-catalyst providing the HER activity for a semiconductor, e.g. Mo3S+4on Si or (2) MoS2 as the semiconductor with an intrinsic HER activity. Finally, suggestions for future catalyst designs are given.

Silicon carbide/silicon rich carbide multilayers, aimed at the formation of silicon nanodots for photovoltaic applications, have been studied. The electrical properties have been investigated at the nano-scale by conductive Atomic Force Microscopy (c-AFM) and at macro-scale by temperature dependent conductivity measurements. The mixture is composed of highly conductive Si nanoclusters and moderately conductive SiC nanoclusters in a disordered matrix. The conduction mechanism takes place via band states induced by the disorder at the interface between nanodot clusters. Structural properties have been extracted by optical spectroscopy analyses. The results contribute to the understanding of the microscopical electronic mechanisms of the composite material, which is a candidate for third generation photovoltaics.

The use of bioethanol as a biofuel make it possible to reduce the dependence on fossil fuel and the greenhouse emissions. The advantage of bioethanol is that is obtained by fermentation of renewable resources that capture carbon dioxide during its growing providing a null net balance of carbon dioxide emissions. Applying the concept of green engineering led to total or partial substitution of fossil fuel. The main drawback is that fermentation is produced in diluted aqueous media and the recovery of ethanol is an energy intensive operation and in Europe, the maximum ethanol content in fuel allowed by legislation is 10% wt (Directive 2009/10/EC). The objective of this project is to provide a process scheme that led to dehydrate bioethanol and blend directly with gasoline and gasoline additive, tert-amyl-methyl ether (TAME). This process must to be viable in terms of energy, economics and environmental aspects. A bibliographic search is presented to determine how much energy is necessary to produce one kilogram of bioethanol. The results of the bibliographic search shown that for a diluted feed stream of ethanol, the best process scheme consist on two distillation columns and one decanter. Hence, five process schemes are presented: (1-3) with the conventional configuration (two distillation column and one decanter) and (4-5) with a novel configuration (one distillation column, with a lateral extraction, and one decanter). The residue curve maps and liquid-liquid equilibrium (RCM-LLE) with their topologies are presented. The RCM-LLE allows to illustrate the thermodynamic behavior of the entrainers used and verify the feasibility. The software used to carry out the rigorous simulations is ASPEN Plus ® v10 using the thermodynamically model NRTL. The annual production established is 18kt/year of a mixture ethanol-gasoline-TAME. The converged results of the simulations allow to compare all the process schemes in terms of energy, sizing and economic aspects, such as raw materials cost, utilities cost, equipment cost and income statement. Beyond this, WAR® is used to compare the environmental impact of each process scheme using coal, oil and natural gas as an energy source Treballs Finals de Màster d'Enginyeria Química, Facultat de Química, Universitat de Barcelona, Curs: 2018-2019, Tutors: Alexandra Bonet Ruiz, Manuel Vicente Buil

Abstract The effect of high temperatures as a degrading factor of rock materials is investigated in this study. Valdieri Marble samples, collected in a quarry in North-western Italian Alps, were subjected to thermal cycles (ranging from 105° to 600 °C) and to subsequent non-destructive and destructive laboratory tests with the aim of evaluating the variation of physical and mechanical properties as a function of temperature variations. Physical and mechanical measurements were complemented with microscopic observations on thin sections. The increase of crack density with temperature and the consequent porosity increases were found to be the main causes of degradation of physical and mechanical properties. In general, density, ultrasonic pulse velocity, wet electrical resistivity, uniaxial compressive strength and Young's moduli decrease as temperature increases. By contrast, peak strain and porosity increase. Correlations between temperature and physical-mechanical properties were proposed and compared to other relationships already established in scientific literature. A damage parameter to quantify the degradation of mechanical properties with temperature is also proposed.

El propòsit de la tesi va ser explorar mitjançant estudis empírics l'evolució de l'ús de les eines Lean a les empreses manufactureres europees i el seu vincle amb les tecnologies de la Indústria 4.0 i les pràctiques green. En primer lloc, es va investigar l'adopció i la internalització de les eines Lean i el seu impacte en el rendiment productiu a les empreses manufactureres espanyoles. Tot seguit, es va analitzar la influència de la internalització de les eines Lean en l'adopció de tecnologies de la Indústria 4.0 a les empreses manufactureres europees. I, finalment, es va examinar la relació entre l'ús conjunt d'eines Lean i les pràctiques green associat a l'exercici mediambiental a les empreses manufactureres espanyoles. La metodologia emprada al llarg dels estudis presentats es va basar en l'anàlisi de dades extretes de la European Manufacturing Survey The purpose of the thesis was to explore through empirical studies the evolution of the use of lean tools in European manufacturing firms and their link with Industry 4.0 technologies and green practices and Circular Economy. First, the adoption and internalisation of lean tools and their impact on production performance in Spanish manufacturing firms were investigated. Next, the influence of the internalisation of Lean tools on the adoption of Industry 4.0 technologies in European manufacturing firms was analysed. Finally, the relationship between the joint use of Lean tools and green practices associated with environmental performance in Spanish manufacturing firms was examined. The methodology employed throughout the studies presented was based on the analysis of data extracted from the European Manufacturing Survey Programa de Doctorat Interuniversitari en Dret, Economia i Empresa

Self-organizing nanopatterns can enable economically competitive, industrially applicable light-harvesting platforms for thin-film solar cells. In this work, we present transparent solar cell substrates having quasiperiodic uniaxial nanowrinkle patterns with high optical haze values. The self-organized nanowrinkle template is created by controlled heat-shrinking of metal-deposited pre-stretched polystyrene sheets. A scalable UV nanoimprinting method is used to transfer the nanopatterns to glass substrates on which single-junction hydrogenated amorphous silicon p-i-n solar cells are subsequently fabricated. The structural and optical analyses of the solar cell show that the nanowrinkle pattern is replicated throughout the solar cell structure leading to enhanced absorption of light. The efficient broadband light-trapping in the nanowrinkle solar cells results in very high 18.2 mA/cm2 short-circuit current density and 9.5% energy-conversion efficiency, which respectively are 35.8% and 39.7% higher than the values obtained in flat-substrate solar cells. The cost- and time-efficient technique introduces a promising new approach to customizable light-management strategies in thin-film solar cells.