Search results for "Hf"
showing 10 items of 909 documents
Unravelling environment and politics in the Spanish press. From Franco’s dictatorship to democracy
2017
The 1970s and 1980s were key years for the consolidation of environmentalism and environmental communication. In Spain, the special political situation during General Franco’s military dictatorship conditioned the coverage of environmental issues, as did the transition to democracy. The Albufera Natural Park (Valencia, Spain) was a particularly significant case in this context, since it was involved in one of the first environmental protests to protect a natural area covered by Spanish media. In this paper, we study opinion articles published in the Valencian newspapers Las Provincias and Levante, in order to analyze the evolution of the environmental discourse in Spanish society from the d…
Development Of An Econometric Model Case Study: Romanian Classification System
2015
Abstract The purpose of the paper is to illustrate an econometric model used to predict the lean meat content in pig carcasses, based on the muscle thickness and back fat thickness measured by the means of an optical probe (OptiGrade PRO).The analysis goes through all steps involved in the development of the model: statement of theory, specification of the mathematical model, sampling and collection of data, estimation of the parameters of the chosen econometric model, tests of the hypothesis derived from the model and prediction equations. The data have been in a controlled experiment conducted by the Romanian Carcass Classification Commission in 2007. The purpose of the experiment was to …
Studies on the microstructure of ethylene/1-hexene copolymers prepared over heterogeneous Ziegler - Natta catalysts
2000
Three MgCl 2(THF) 2-supported, AlEt 2Cl-activated VOCl 3, VCl 4 and TiCl 4 Ziegler - Natta catalysts were used to copolymerize ethylene with 1-hexene in the presence of hydrogen to prepare low-M well-soluble copolymers that could be analyzed by 13C-NMR. The spectra (Fig. 1) showed resonance signals due to ethylene and 1-hexene units in positions unaffected by catalyst type and with intensities related to the degree of comonomer incorporation into the copolymer. The triad sequence distribution and comonomer reactivity ratios (r) were calculated by the Randall method [11] and Bernoulli statistics based on the known copolymer composition. The latter appeared to be the more valid in predicting …
EUROPEAN INSTITUTIONS ON SOCIAL MEDIA ‒ SHAPING THE NOTION OF EUROPEAN CITIZENSHIP
2017
Abstract This study supports topical discussion about the possibilities to use social media as a tool for citizen involvement in democratic processes. Contemporary academic views and statistics on the use of social media for communication between institutions and citizens are gathered in the study. The research focus is on social media publications, analysing the content of four European Parliament’s social media accounts in Latvian during the period from 1 July 2015 to 31 December 2015. The aim of the research is to identify the potential of the information published on European Parliament’s social media accounts in shaping the European citizenship notion among youth in Latvia. The conclus…
Durée et fréquence des vagues de chaleur en Afrique tropicale septentrionale selon 5 indices de chaleur.
2019
Thermal extremes generate health risks that are increasingly taken into account, including in tropical Africa. This work compares the duration and the frequency of spring heat waves (HWs) in West Africa according to 5 indices: Warm Spell (WS), Heat Index (HI) with and without the relative humidity, Apparent Temperature (AT), and Excess Heat Factor (EHF). The daily relative humidity and temperature data (minimum, maximum, dew point are provided by the GSOD database for the period 1973-2014 and cover 145 stations spread over a large African area (3-24°N; 24°W-36°E). The results show that the duration of the HWs is short on the coast (3 days) and they last longer inland the continent and in th…
Durée et fréquence des vagues de chaleur en Afrique tropicale septentrionale selon 5 indices de chaleur
2019
Thermal extremes generate health risks that are increasingly taken into account, including in tropical Africa. This work compares the duration and the frequency of spring heat waves (HWs) in West Africa according to 5 indices: Warm Spell (WS), Heat Index (HI) with and without the relative humidity, Apparent Temperature (AT), and Excess Heat Factor (EHF). The daily relative humidity and temperature data (minimum, maximum, dew point are provided by the GSOD database for the period 1973-2014 and cover 145 stations spread over a large African area (3-24°N; 24°W-36°E). The results show that the duration of the HWs is short on the coast (3 days) and they last longer inland the continent and in th…
Generation of energy selective excitations in quantum hall edge states
2011
We operate an on-demand source of single electrons in high perpendicular magnetic fields up to 30T, corresponding to a filling factor below 1/3. The device extracts and emits single charges at a tunable energy from and to a two-dimensional electron gas, brought into well defined integer and fractional quantum Hall (QH) states. It can therefore be used for sensitive electrical transport studies, e.g. of excitations and relaxation processes in QH edge states.
Production of neutron deficient rare isotope beams at IGISOL; on-line and off-line studies
2004
This article reports on recent on-line yield measurements employing the light-ion and heavy-ion reaction-based ion guide systems and new results on a-recoil ion transport properties in ion guides with and without electric fields. In addition, the presently used ion guide designs for fusion evaporation reactions are introduced. The present study investigated different schemes for ion extraction from the gas cell. The addition of an extra ring electrode between the traditional skimmer electrode and the exit hole led to transmission independent of the primary beam intensity as opposed to strong intensity dependence observed earlier with the plain skimmer only. Furthermore, the mass resolving p…
Participación ciudadana en los perfiles de Facebook de los partidos españoles. Análisis de comentarios en la campaña electoral de 2015
2017
El uso de redes sociales por parte de los partidos políticos para la difusión de sus mensajes posibilita la participación ciudadana y la creación de debate entre los usuarios. El presente estudio analiza esta participación a través de los comentarios que escriben los ciudadanos en las páginas de Facebook de los principales partidos políticos españoles durante la campaña de las elecciones generales de 2015. El objetivo es establecer las características de la participación ciudadana en un contexto político y comprobar si existen diferencias entre los comentarios publicados en los distintos partidos. El estudio utiliza una metodología cuantitativa articulada en dos fases. En primer lugar, se a…
Facebook’s ad hoc groups: a potential source of communicative power of networked citizens
2017
Ad hoc groups (sporadically formed on social network sites for achieving particular common objectives) have been seen as a public space for citizen participation and debate. This study focuses on Facebook’s ad hoc groups in Finland. The aim is to detect the potential of these groups to enhance networked citizens’ communicative power for raising societally important issues to public agenda and initiate changes in society. We suggest a categorization of the groups according to their missions, and present their members’ specific motivations and objectives through an online survey. Despite the general entertainment-orientation and self-referential nature of social media, the results show that a…