Influence of building use on comfort and energy performance in offices

This paper investigates the influence of different building use by companies and individual occupants on thermal and visual comfort, energy consumption and CO2 emissions in mixed mode offices. Adaptive thermal comfort evaluation according to EN 15251 has been used during natural ventilation and cooling

Context dependency of comfort and energy performance in mixed mode offices

This article investigates the context dependency of comfort and energy performance in mixed-mode offices in the climate of Athens, Greece. It is based on a parametric study using the simulation software EnergyPlus. Context refers to different building design priorities on the real estate market (prestige, low cost and green), occupant behaviour scenarios (ideal and worst case) and cooling strategies (fixed and adaptive set points). Results are evaluated according to energy consumption and related greenhouse gas emissions, daylight autonomy, view and percentage of working time when heating and cooling are operating. The results indicate that a holistic approach to comfort and energy performance evaluation focused on the specific context of a building and its occupants is necessary to develop appropriate optimization strategies. In early design stages, such specific information is not yet available and ideal/worst-case scenarios can indicate the magnitude of influence of occupants compared to building design.<br /

Balancing buildings and occupants - a holistic approach to thermal comfort and greenhouse gas emissions in mixed mode offices

This paper describes a holistic approach to comfort and greenhouse gas emissions in mixed mode offices. It is based on parametric studies for a typical cellular office in the Mediterranean climate of Athens, Greece, using building simulation.Considered parameters are the influence of different building design, varying occupant behaviour and internal heat loads, as well as of an exceptionally hot summer. Additionally, the performance of a cooling strategy following the comfort limits according to the EN 15251 adaptive model is compared with the common fixed cooling set point 22&deg;C.The performance of mixed mode offices is evaluated regarding thermal comfort, daylight autonomy and related greenhouse gas emissions. Results indicate strategies to improve sustainability in mixed mode offices in Athens, by balancing the influencing parameters.<br /

Cosmic-ray propagation properties for an origin in SNRs

We have studied the impact of cosmic-ray acceleration in SNR on the spectra of cosmic-ray nuclei in the Galaxy using a series expansion of the propagation equation, which allows us to use analytical solutions for part of the problem and an efficient numerical treatment of the remaining equations and thus accurately describes the cosmic-ray propagation on small scales around their sources in three spatial dimensions and time. We found strong variations of the cosmic-ray nuclei flux by typically 20% with occasional spikes of much higher amplitude, but only minor changes in the spectral distribution. The locally measured spectra of primary cosmic rays fit well into the obtained range of possible spectra. We further showed that the spectra of the secondary element Boron show almost no variations, so that the above findings also imply significant fluctuations of the Boron-to-Carbon ratio. Therefore the commonly used method of determining CR propagation parameters by fitting secondary-to-primary ratios appears flawed on account of the variations that these ratios would show throughout the Galaxy.Comment: Accepted for publication in Ap

Jet quenching in relativistic heavy ion collisions

Parton propagation in dense nuclear matter results in elastic, inelastic and coherent multiple soft scattering with the in-medium color charges. Such scattering leads to calculable modifications of the hadron production cross section that is evaluated in the framework of the perturbative QCD factorization approach. Final state medium-induced gluon bremsstrahlung is arguably the most efficient way of suppressing large transverse momentum particle production in nucleus-nucleus collisions. The observed hadronic attenuation, known as jet quenching, can be related to the properties of the medium, such as density and temperature, and carries valuable information about the early stages of heavy ion reactions. Non-Abelian energy loss in the quark-gluon plasma can be studied in much greater detail through the modification of the two particle back-to-back correlations. Perturbative calculations give good description of the redistribution of the lost energy in lower transverse momentum particles and predict significant increase of the correlation width of away-side di-hadrons. In contrast, energy loss in cold nuclear matter was found to be small but for large values of Feynman-x is expected to complement the dynamical higher twist shadowing in experimentally observable forward rapidity hadron suppression.Comment: Invited plenary talk at the V-th international conference on the physics and astrophysics of the quark-gluon plasma. 8 pages, 4 figure

The influence of new media on brand perception and purchase intention of luxury brands : the example of Yves Saint Laurent

Social media enables marketers to address consumers directly through creative and innovative marketing strategies. By using different platforms, content can be adapted to fit the needs of different target groups. In addition, previous research indicates that word-of-mouth, being a strong influencer on the customer’s perception in any purchase situation, also plays a big role in social media. However, social media is not being used in a similar vein across different products/brands. In fact, the luxury segment is considered a digital latecomer, wanting to be in control of distribution channels and thus being slow to pick up on digital and e-commerce trends. This study examines how social media tools influence consumers’ perception and purchase intention of luxury brands, with a special focus on the brand Yves Saint Laurent Beauté. By exposing 151 respondents to different kinds of consumer-generated-content, this study proposes a model that assesses the influence of such social media content on luxury brand perception and purchase intention. The study tests the hypothesized model using a between-subject design by comparing pre- and post-luxury perceptions. The results indicate that social media has a positive impact on the purchase intention and brand perception of luxury products. Additionally, results show that this effect holds true for both, luxury affine and luxury averse respondents, but results are not always similar across social media tools. Thus, the study advices luxury brand managers to apply customized social media tools, depending on the segment they are targeting.Os meios sociais permitem que os profissionais de marketing abordem diretamente os consumidores através de estratégias de marketing criativas e inovadoras pois ao usar diferentes plataformas, os conteúdos podem ser adaptados para atender às necessidades de diferentes públicos-alvo. Estudos anteriores indicam os meios sociais não estão a ser usados de forma semelhante em produtos ou marcas de diferente natureza. Por exemplo, o segmento dos produtos de luxo é considerado como retardatário dos meios digitais, pois ao querer estar em pleno controle de seus canais de distribuição, tem sido lento a acompanhar as tendências digitais e de e-commerce. Esta dissertação examina como as ferramentas de meios sociais influenciam a percepção dos consumidores e a intenção de compra de marcas de luxo, com enfoque especial na marca Yves Saint Laurent Beauté. Ao expor 151 entrevistados a diferentes tipos de conteúdos gerado pelo consumidor, este estudo propõe um modelo que avalia a influência destes conteúdos na perceção das marcas de luxo e intenção de compra dos consumidores. Os resultados indicam que os meios sociais têm um impacto positivo sobre a intenção de compra e perceção da marca de produtos de luxo. Além disso, resultados sugerem que esse efeito é válido tanto para os apreciadores do luxo como para os avessos ao luxo, mas que diferem em função das ferramentas de meios sociais usadas. Assim, o estudo aconselha os gestores de marcas de luxo a adotarem ferramentas personalizadas de meios sociais, em função do segmento alvo de consumidores em que se estão a focar