scholarly journals Antenna with optimized pattern for simultaneous reception of terrestrial signals and signals of geostationary satellites

2010 ◽  
Vol 8 ◽  
pp. 37-42 ◽  
Author(s):  
G. Saala ◽  
D. Müller ◽  
J. Hopf ◽  
S. Lindenmeier

Abstract. The link margin for satellite communication services targeting mobile users is tight. This leads to reception problems in areas with strong fading scenarios like urban areas or forested areas with dense foliage. In order to avoid loss of service in urban areas with week coverage by satellite signals, terrestrial repeaters are used. Therefore in the design of antennas for mobile reception of satellite services, an optimized characteristics for the satellite constellation, as well as an adequate coverage of the terrestrial repeaters has to be accounted for. In this paper an antenna with optimum shaped pattern for the satellite mode and adjustable gain for vertical polarization is investigated. Beside constraints regarding the radiation pattern, measurements concerning the dependence of the antenna on noise temperature and therefore the behavior in real noisy environments are carried out. A comparison with a conventional antenna shows the high performance of the new antenna in combination with a very low volume requirement.

2021 ◽  
Vol 11 (15) ◽  
pp. 6736
Author(s):  
Ong Heo ◽  
Yeowon Yoon ◽  
Jinung Do

When underground space requires excavation in areas below the water table, the foundation system suffers from buoyancy, which leads to the uplifting of the superstructure. A deep foundation system can be used; however, in cases where a hard layer is encountered, high driving forces and corresponding noises cause civil complaints in urban areas. Micropiles can be an effective alternative option, due to their high performance despite a short installation depth. Pressurized grouting is used with a packer to induce higher interfacial properties between micropile and soil. In this study, the field performance of micropiles installed using gravitational grouting or pressure-grouted using either a geotextile packer or rubber packer was comparatively evaluated by tension and creep tests. Micropiles were installed using pressure grouting in weak and fractured zones. As results, the pressure-grouted micropiles showed more stable and stronger behaviors than ones installed using the gravitational grouting. Moreover, the pressure-grouted micropile installed using the rubber packer showed better performance than the one using the geotextile packer.


2021 ◽  
Vol 13 (16) ◽  
pp. 8789
Author(s):  
Giovanni Bianco ◽  
Barbara Bonvini ◽  
Stefano Bracco ◽  
Federico Delfino ◽  
Paola Laiolo ◽  
...  

As reported in the “Clean energy for all Europeans package” set by the EU, a sustainable transition from fossil fuels towards cleaner energy is necessary to improve the quality of life of citizens and the livability in cities. The exploitation of renewable sources, the improvement of energy performance in buildings and the need for cutting-edge national energy and climate plans represent important and urgent topics to be faced in order to implement the sustainability concept in urban areas. In addition, the spread of polygeneration microgrids and the recent development of energy communities enable a massive installation of renewable power plants, high-performance small-size cogeneration units, and electrical storage systems; moreover, properly designed local energy production systems make it possible to optimize the exploitation of green energy sources and reduce both energy supply costs and emissions. In the present paper, a set of key performance indicators is introduced in order to evaluate and compare different energy communities both from a technical and environmental point of view. The proposed methodology was used in order to assess and compare two sites characterized by the presence of sustainable energy infrastructures: the Savona Campus of the University of Genoa in Italy, where a polygeneration microgrid has been in operation since 2014 and new technologies will be installed in the near future, and the SPEED2030 District, an urban area near the Campus where renewable energy power plants (solar and wind), cogeneration units fed by hydrogen and storage systems are planned to be installed.


2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Manuel Romana ◽  
Marilo Martin-Gasulla ◽  
Ana T. Moreno

Most of the rural transportation system is composed of two-lane highways, and many of them serve as the primary means for rural access to urban areas and freeways. In some highways, traffic volumes can be not high enough to justify a four-lane highway but higher than can be served by isolated passing lanes, or can present high number of head-on collisions. In those conditions, 2 + 1 highways are potentially applicable. This type of highway is used to provide high-performance highways as intermediate solution between the common two-lane highway and the freeway. Successful experiences reported in Germany, Sweden, Finland, Poland, or Texas (US) may suggest that they are potentially applicable in other countries. The objective of this white paper is to provide an overview of the past practice in 2 + 1 highways and discuss the research directions and challenges in this field, specially focusing on, but not limited to, operational research in association with the activities of the Subcommittee on Two-Lane Highways (AHB40 2.2) of the Transportation Research Board. The significance of this paper is twofold: (1) it provides wider coverage of past 2 + 1 highways design and evaluation, and (2) it discusses future directions of this field.


2011 ◽  
Vol 11 (12) ◽  
pp. 3343-3358 ◽  
Author(s):  
M. G. Pereira ◽  
B. D. Malamud ◽  
R. M. Trigo ◽  
P. I. Alves

Abstract. We focus here on a mainland Continental Portuguese Rural Fire Database (PRFD) that includes 450 000 fires, the largest such database in Europe in terms of total number of recorded fires in the 1980–2005 period. In this work, we (a) list the most important factors for triggering and controlling the fire regime in mainland Continental Portugal, (b) describe the dataset's production, (c) discuss procedures adopted to identify and correct different fire data inconsistencies, creating a modified PRFD which we use here and make available as Supplement, (d) explore some basic temporal and completeness properties of the data. We find that the dataset's minimum measured burnt areas have changed with time between AF = 0.1 ha (1980–1990), AF = 0.01 ha (1991–1992), and AF = 0.001 ha (1992–2005), with varying degrees of completeness down to these values. These changes in minimum area measured are responsible for greater numbers of fires being recorded. A relatively small number of large fires in the PRFD are responsible for the majority of the burnt area. For example, fires with AF > 100 ha represent about 1% of all fire records but 75% of total burnt area. Finally, we consider for each Continental Portugal district and for the 26-yr period, the total number of rural fires and area burnt in forests and shrublands, each normalized by district areas. We find that the highest numbers of fires per unit area are in highly populated districts, and that the largest fraction of burnt area is in forested areas, coinciding with large parcels of continuous forests (predominantly rural and moderately urban areas).


2020 ◽  
Author(s):  
Felix Bachofer ◽  
Thomas Esch ◽  
Jakub Balhar ◽  
Martin Boettcher ◽  
Enguerran Boissier ◽  
...  

<p>Urbanization is among the most relevant global trends that affects climate, environment, as well as health and socio-economic development of a majority of the global population. As such, it poses a major challenge for the current urban population and the well-being of the next generation. To understand how to take advantage of opportunities and properly mitigate to the negative impacts of this change, we need precise and up-to-date information of the urban areas. The Urban Thematic Exploitation Platform (UrbanTEP) is a collaborative system, which focuses on the processing of earth observation (EO) data and delivering multi-source information on trans-sectoral urban challenges.</p><p>The U-TEP is developed to provide end-to-end and ready-to-use solutions for a broad spectrum of users (service providers, experts and non-experts) to extract unique information/ indicators required for urban management and sustainability. Key components of the system are an open, web-based portal connected to distributed high-level computing infrastructures and providing key functionalities for</p><p>i) high-performance data access and processing,</p><p>ii) modular and generic state-of-the art pre-processing, analysis, and visualization,</p><p>iii) customized development and sharing of algorithms, products and services, and</p><p>iv) networking and communication.</p><p>The service and product portfolio provides access to the archives of Copernicus and Landsat missions, Datacube technology, DIAS processing environments, as well as premium products like the World Settlement Footprint (WSF). External service providers, as well as researchers can make use of on-demand processing of new data products and the possibility of developing and deploying new processors. The onboarding of service providers, developers and researchers is supported by the Network of Resources program of the European Space Agency (ESA) and the OCRE initiative of the European Commission.</p><p>In order to provide end-to-end solutions, the VISAT tool on UrbanTEP allows analyzing and visualizing project-related geospatial content and to develop storylines to enhance the transport of research output to customers and stakeholders effectively. Multiple visualizations (scopes) are already predefined. One available scope exemplary illustrates the exploitation of the WSF-Evolution dataset by analyzing the settlement and population development for South-East Asian countries from 1985 to 2015 in the context of the Sustainable Development Goal (SDG) 11.3.1 indicator. Other open scopes focus on urban green, functional urban areas, land-use and urban heat island modelling (e.g.).</p>


2019 ◽  
Vol 12 (4) ◽  
pp. 253-263
Author(s):  
Don Jethro Mavungu Landu ◽  
Michel Frédérich ◽  
Joseph Manzambi Kuwekita ◽  
Christian Bongo-Pasi Nswe ◽  
J K Mbinze ◽  
...  

Abstract Background In the context of old pharmaceutical legislation and regulations not adapted to current realities, the aim of the present study was to evaluate the existing pharmaceutical system in peri-urban areas of Kinshasa. Methods A prospective study was carried out during the period 2016–2018. The most used antimalarial medicines were identified through household and pharmaceutical establishment surveys. The samples of the obtained medicines were assayed with generic separation methods using the high-performance liquid chromatography technique coupled to a diode array detector. The registration status was checked for 126 antimalarial brand names. A characterization was carried out in 196 pharmaceutical establishments on the basis of standards set out by the Ministry of Health. Results Of the 75 samples assayed, 19% (14/75) were non-compliant. Of the 124 brand names, 46.0% (57/124) were unlicensed and 14.5% (18/124) had an expired licence. Of the 196 pharmaceutical establishments, only 2 (1.0%) had an authorization to practice, none met all the Ministry of Health minimum standards and 24.5% (48/196) met the World Health Organization Guidelines for the Storage of Essential Medicines and Other Health Commodities. Conclusions More resources should be mobilized to apply regulator sanctions.


2011 ◽  
Vol 05 (03) ◽  
pp. 271-282 ◽  
Author(s):  
M. HORI ◽  
G. SOBHANINEJAD ◽  
T. ICHIMURA ◽  
M. LALITH

Integrated earthquake simulation (IES) is a system to estimate possible earthquake hazard and disaster which can take place in an urban area by means of seamless numerical computation. High-performance computing (HPC) is enhanced so that IES is able to simulate a larger area in a shorter time, by improving the system architecture and adding new elements which smoothens the system's efficiency. It is shown in numerical experiments (which are carried out for actual urban areas) that the performance of IES enhanced with HPC is satisfactory. A new system is developed to generate a hazard map which depicts earthquake damages in higher spatial resolution by taking advantage of IES enhanced with HPC. It is shown that such maps can be generated for Tokyo metropolis in half a day.


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