Portable low profile antenna at X-band

An antenna which has been conceived as a portable system for satellite communications based on the recommendations ITU-R S.580-6 and ITU-R S.465-5 for small antennas, i.e., with a diameter lower than 50 wavelengths, is introduced. It is a planar and a compact structure with a size of 40×40×2 cm. The antenna is formed by an array of 256 printed elements covering a large bandwidth (14.7%) at X-Band with a VSWR of 1.4:1. The specification includes transmission (Tx) and reception (Rx) bands simultaneously. The printed antenna has a radiation pattern with a 3dB beamwidth of 5°, over a 31dBi gain, and a dual and an interchangeable circular polarization

Structure and mineralogy of a gold ore body of shear zone origin: the Fosas de Vila ore. La Coruña. Spain

[Abstract] This paper studies a shear zone containing a gold-bearing milonitic body, in which, evidences of several mining works are still visible. The geometry of the structure is described, as well as the different evolutive stages of the milonitic body and the mineralizations associated with them

Conceptualization in the circular economy: analysing the influence of thinking profiles in creative groups

Eco-innovation initiatives include eco-ideation processes for proposing ideas that are innovative and represent an environmental improvement. The evaluation of the results of eco-ideation has been focused on evaluating these two aspects, but it is necessary to know how related factors, such as the thinking profile of group members, influence the generation of concepts during the creative process. This study proposes a metric that analyses the results of the creative process within conceptualization from three approaches: innovation, circularity and group activity. The group activity approach is related to the influence of the leader in the management of a creative group. The proposed metric allows us to observe the creative process, the interactions among the participants, the design decisions made, and the evaluation of the creative product which will determine which type of creative groups obtain better results. The application of the results and the proposed metric allow the creation of groups oriented to objectives, for both specific or permanent workgroups. This can be used for the initial selection of participants for eco-ideation groups, or to improve the group functionality during intermediate stages

Modular Planar Antenna at X-band for satellite communications

An antenna which has been conceived as a portable system for satellite communications based on the recommendations ITU-R S.580-6 [1] and ITU-R S.465-5 [2] for small antennas, i.e., with a diameter lower than 50 wavelengths, is introduced. It is a planar and a compact structure with a size of 40×40×2 cm. The antenna is formed by an array of 256 printed elements covering a large bandwidth (14.7%) at X-Band. The specification includes transmission (Tx) and reception (Rx) bands simultaneously. The printed antenna has a radiation pattern with a 3dB beamwidth of 5°, over a 31dBi gain, and a dual and an interchangeable circular polarizatio

Planktonic Chlorophyceae from the lower Ebro River (Spain)

On samples obtained in 4 seasonal periods between April 1999 and February 2000 from the last 18 km of Ebro River (Spain) some interesting planktonic coccal green algae (Chlorophyceae) were found. This paper offers comments and taxonomical observations on 60 taxa. Crucigenia smithii (Kirchner) W. et G. S. West, Crucigeniella pulchra (W. et G.S.West) Komárek, Elakatothrix genevensis (Reverdin) Hindák, E. subacuta Koršikov, Nephrocytium schilleri (Kammerer) Comas, Oocystidium ovale Kor{ikov, Pseudoschroederia antillarum (Komárek) Hegewald et Schnepf, Scenedesmus denticulatus var. fenestratus (Teiling) Uherkovich, S. pannonicus Hortobágyi, Siderocelis ornata (Fott) Fott, Tetrachlorella alternans (G.M. Smith) Koršikov and Tetrastrum komarekii Hindák were found for the first time in this country. The best represented genus was Scenedesmus, with 16 taxa

Energy Self-Sufficiency Urban Module (ESSUM): GIS-LCA-based multi-criteria methodology to analyze the urban potential of solar energy generation and its environmental implications

The concentration of the population in cities has turned them into sources of environmental pollution, however, cities have a great potential for generating clean energy through renewable sources such as a responsible use of solar energy that reaches its rooftops. This work proposes a methodology to estimate the level of energy self-sufficiency in urban areas, particularly in a district of the city of Zaragoza (Spain). First, the Energy Self-Sufficiency Urban Module concept (ESSUM) is defined, then the self-sufficiency capacity of the city or district is determined using Geographical Information Systems (GIS), Light Detection and Ranging (LiDAR) point clouds and cadastral data. Secondly, the environmental implications of the implementation of these modules in the rooftops of the city using the LCA methodology are calculated. The results obtained show that total self-sufficiency of Domestic Hot Water (DHW) can be achieved using 21 % of available rooftop area, meanwhile the rest of rooftop area, dedicated to photovoltaic (PV), can reach 20 % of electricity self-sufficiency, supposing a final balance of a reduction in CO2 emissions of 12,695.4 t CO2eq/y and energy savings of 372,468.5 GJ/y. This corresponds to a scenario where full self-sufficiency of DHW was prioritized, with the remaining roof area dedicated to PV installation. In addition, other scenarios have been analyzed, such as the implementation of the energy systems separately

Heating energy consumption and environmental implications due to the change in daily habits in residential buildings derived from COVID-19 crisis: The case of Barcelona, Spain

The COVID-19 crisis has changed daily habits and the time that people spend at home. It is expected that this change may have environmental implications because of buildings’ heating energy demand. This paper studies the energy and environmental implications, from a Life Cycle Assessment (LCA) approach, due to these new daily habits in residential buildings at their current level of thermal insulation, and in different scenarios of thermal retrofit of their envelope. This study has a building-to-building approach by using Geographical Information Systems (GIS) for the residential housing stock in the case of Barcelona, Spain. The results show that a change in daily habits derived from the pandemic can increase the heating energy consumption and carbon dioxide emission in residential buildings by 182%. Retrofitting all buildings of Barcelona, according to conventional energy renovation instead of nearly Zero Energy Buildings (nZEB), will produce between 2.25 × 107 and 2.57 × 107 tons of carbon dioxide. Retrofitting the building stock using energy recovery is the option with better energy and emission savings, but also is the option with higher payback time for buildings built until 2007. The methodology presented can be applied in any city with sufficient cadastral data, and is considered optimal in the European context, as it goes for calculating the heating energy consumption

A robust procedure for damage detection from strain measurements based on principal component analysis

FBGs are excellent strain sensors, because of its low size and multiplexing capability. Tens to hundred of sensors may be embedded into a structure, as it has already been demonstrated. Nevertheless, they only afford strain measurements at local points, so unless the damage affects the strain readings in a distinguishable manner, damage will go undetected. This paper show the experimental results obtained on the wing of a UAV, instrumented with 32 FBGs, before and after small damages were introduced. The PCA algorithm was able to distinguish the damage cases, even for small cracks. Principal Component Analysis (PCA) is a technique of multivariable analysis to reduce a complex data set to a lower dimension and reveal some hidden patterns that underlie