5,967 research outputs found
Juan de Arfe y la custodia de la Catedral de Ávila. Nuevos datos
En este estudio presentamos y analizamos nueva documentación sobre el platero Juan de Arfe y su trabajo en la custodia de la catedral de Ávila. El legajo, conservado en el Archivo Diocesano de Ávila, contiene un duplicado del contrato, correspondencia enviada por Arfe al cabildo, cartas de pago y de poder, y la tasación completa de la custodia. A través de estos documentos podremos conocer el nombre de algunos de los oficiales vinculados a su taller y detalles del proceso creativo de la pieza, ampliando significativamente el conocimiento de su primera gran obra
Dual band printed antenna
The invention consists of a dual band printed antenna planned to be implemented preferably in base stations of dual mobile telephony which use GSM and DCS-1800 systems, although other applications are not rejected.Similarly to the well-known printed antennas, the invented antenna has a dielectric substrate layer whose front side presents a printed patch. This patch is fed by the conventional microstrip line technique that is why the front side presents a microstrip line stretch reaching the patch. The dielectric layer’s backside presents an electric Earth reference. So far, this structure corresponds to the known as ‘printed antennas’.Optionally, the dielectric layer’s backside can include a metallic strip that will facilitate the adjustment corresponding to the bandwidth. The antenna’s microstrip line and the Earth reference can be connected to a SMA connector in order to facilitate feeding. This Earth reference, according to a preferential performance, has the same length as the microstrip line. In other performances, this reference could be placed perpendicular to the radiating patch enabling an omnidirectional configuration of the antenna. Depending on different performances and the sought radiation patterns, the dielectric layer’s backside could have a metallic plug joint to the Earth reference and/or a PTFE element (polytetrafluoroethylene, commonly known as Teflon). In that case, the PYFE element position has been planned to be either following the plug or between the plug and the Earth reference.The antenna has a dielectric substrate layer whose front side presents a patch antenna fed by a microstrip line stretch and whose back side presents an Earth reference. This patch has the shape of an isosceles triangle which connects one vertex to the stretch, while in parallel to the opposite side of the vertex, there is a slot in the patch operating like a filter. This enables a dual band operation wherein two resonant frequencies are controlled by the variation of the patch size and the slot length. The frequencies can be adjusted to values of 900 and 1800 MHz, facilitating the application of the antenna in dual mobile telephony with GSM and DCS-1800 systems. With this technological offer we try to collaborate with licence agreement and commercial agreement with technical assistance.Dual frequency operation. Low fabrication cost.Diseño de estructuras radiantes para sistemas de telecomunicación, Diseño y fabricación de circuitos de microondas,Diseño y fabricación de estructuras de calentamiento industrial por microondas,Técnicas de medida de compatibilidad electromagnética
Dual band antenna for mobile terminals
The proposed antenna belongs to the area of integrated antennas with optimum features, and it is materialised in a metallic patch parallel to a Earth reference. The patch is preferably a rectangle but it can also have a trapezoidal shape, incorporating an only feeding pin and a short circuit which connect the antenna to the Earth reference.The antenna is approximately as long as a quarter of the highest resonance frequency’s wavelength, while the lowest resonance frequency is determined by a band-stop filter called spur-line, parallel to three out of four sides of the patch.The fact that the short circuit is placed in the furthest area from the slot or spur-line along the perimeter let us obtain a second resonance at a lower frequency than the original patch’s resonant frequency.The antenna has a metallic rectangular patch placed in a plane parallel to the Earth reference, which it is connected to by a metallic pin that acts as feeding point and another one as a short circuit. The patch is approximately as long as a quarter of the highest resonant frequency’s wavelength. The lowest resonant frequency is obtained from a spur band-stop filter parallel to three out of four sides of the patch.With this technological offer we try to collaborate with licence agreement and comercial agreement with technical assistance.Dual operation in small space. Low fabrication cost. Extension to other frequency bands.Diseño de estructuras radiantes para sistemas de telecomunicación.Diseño y fabricación de circuitos de microondas. Técnicas de medida de compatibilidad electromagnética
Radiocommunications, electromagnetism and microwave engineering research group (GIMRE)
The main activities, research lines and results of the Radiocommunications, Electromagnetism and Microwave Engineering Research Group (GIMRE) at the Technical
University of Carthagene are portrayed. With just 8 years of activity, GIMRE is reaching maturity as a high-scientific achievement R&D group in the Region of Murcia, Spain
Knowledge Creating and Sharing Corporate Culture Framework
AbstractMost knowledge - and particularly know-how - tends to be implicit, difficult to communicate in an easy form, and sometimes impossible to document, this is the tacit knowledge. Tacit knowledge provides competitive advantage for future successful companies. Making tacit knowledge available to others should be the central activity of the knowledge and innovation creating organization. A prerequisite for the evolution of tacit knowledge is an open culture in an organization, interaction with others. So, knowledge sharing is the fundamental means through which employees can contribute to knowledge creating, innovation, and ultimately the competitive advantage of the organization. But there are some barriers in the creation and sharing knowledge so that they become critical processes in corporate knowledge management. This paper proposes a framework approach, to integrate creation and sharing knowledge process, based on the resolution of the main walls which exist within both process, and which the company can exploit using different tools. The expected benefits of this approach include personal satisfaction and development, rationalization of decision-making processes by making them explicit, increase productivity, increasing knowledge creation and sharing culture and innovation
Communication of corporate social responsibility in Spanish organizations whit the best reputation
Este trabajo afronta la relación existente entre la RSC y la reputación corporativa desde el punto de vista de la comunicación. Para analizar esta relación, nos apoyaremos en el ranking de reputación Merco (líder en España). En primer lugar, se identifican las variables de RSC utilizadas para elaborar el ranking. En segundo lugar, se realiza un análisis de contenido de las webs corporativas de las diez primeras organizaciones del ranking para identificar si dichas variables están presentes y son comunicadas. Los resultados indican que no se da una correlación directa entre reputación y comunicación de RSC a través de la web, al menos en lo que respecta a las cuatro primeras organizaciones del ranking. De hecho, llama la atención que la primera organización del ranking es, sin embargo, la que menos comunica su RSC en la web.This paper analyzes the relationship between CSR and corporate reputation from the point of view of communication. To study this relationship, we will rely on the Merco reputation ranking (leader in Spain). First, we identify the CSR variables used to compile the ranking. Secondly, a content analysis of the corporate websites of the top ten ranking organizations is carried out to identify if these variables are present and are communicated. The results indicate that there is no direct correlation between reputation and CSR communication over the web, at least for the first four ranking organizations. In fact, it is striking that the first organization of the ranking is, however, the one that least communicates its CSR on the web.Ciencias de la Comunicació
Novel printed bow-tie antennas for dual-band dual-mode mobile handsets
The development of dual-band dual-mode D-AMPS/AMPS mobile handsets and radio stations has added pressure on GSM service providers to follow similar technology breakthroughs as a first step towards UMTS/FPLMTS. A frequency agile device accommodating both GSM standard frequency bands would serve more than 25 million GSM subscribers, with expectations as high as 100 millions subscribers by the year 2000. The complexity of the spectrum sharing between the two technologies and service generations may be alleviated by all terminal, system and network technologies. Several attempts to accomplish dual-band GSM/DCS 1800 operation on a single handset employing dual-band antenna concepts are introduced, and novel printed antenna elements developed at the Universidad Politécnica de Valencia are described.This work was supported by the Spanish Comisión Interministerial de Ciencia y Tecnologia, CICYT, under
the TIC95-0983-C03-02 research project (Universidad Politécnica de Valencia)
Exposición de una cabeza humana a radiofrecuencia
En esta contribución, un plano coronal de cabeza humana es expuesto a 125 mW de potencia radiada por un dipolo de media onda a 1800 MHz. Se proporcionan tanto la TAE (Tasa de Absorción Específica) como los incrementos de temperatura asociados a la exposición electromagnética, para distintos escenarios. Se evalúa el efecto en el confort térmico de los procesos termorregulatorios humanos. Se presenta un importante efecto de adaptación entre el dipolo y la cabeza humana, así como al cráneo como protector del encéfalo ante tensiones térmicas debidas a exposición a campo EM. Como resultado del estudio, se podrían derivar restricciones básicas más precisas combinando los límites de TAE con la respuesta térmica asociada.Esta investigación ha sido financiada parcialmente por la Fundación Séneca, Agencia de Ciencia y Tecnología de la Región de Murcia, a través de una ayuda del Programa Séneca
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