Evaluation of scale-adaptive simulation for transonic cavity flows

Scale-adaptive simulations of transonic cavities with and without doors are presented in this paper. Results were compared with detached-eddy simulations for cavities with length-to-depth ratios of 5 and 7. The Mach and Reynolds numbers (based on the cavity length) were 0.85 and 6.5 × 106, respectively, and the grid sizes were 5.0 million for the clean cavity with doors-off and 5.5 million for the clean cavity with doors-on. Instantaneous Mach number contours showed that the shear layer broke down for both the doors on and doors off cases and that the flows had a high level of unsteadiness inside them. The two L/D ratios of cavities were seen to have similar acoustic signatures reaching maximum sound levels of 170 dB. Spectral analyses for the cavities without doors revealed that by changing the length-to-depth ratio from five to seven, the dominant acoustic modes at the front and rear of the cavities were shifted from the second and third modes to the first and second modes respectively. Proper orthogonal decomposition was used to reduce the data storage using modes constructed from flowfield snapshots taken at regular intervals

Effective education for energy efficiency

A lot of today's world vices can be eliminated if certain targeted modules and adapted curricula are introduced in the schooling system. One of these vices is energy squandering with all its negative consequences for the planet (e.g. depletion of finite energy sources and the subsequent climate change). This paper describes the results of an energy-thrift information and education project taking place in different levels of education in Crete--Greece, which records 321 students' and their parents' routine energy-related behavior and proves that this behavior changes to a more energy efficient one, after the dissemination of relevant information and the participation into the energy education projects. Namely, response percentages indicating the energy-efficient behavior increased after project participation while the ones indicating an energy-squandering behavior decreased. The Wilcoxon signed rank test was statistically significant in all energy behavior questions related to students and to most questions related to parents.

Increased density of cutaneous nerve fibres in the affected dermatomes after herpes zoster therapy

Herpes zoster neural injury was assessed by determining cutaneous nerve density in skin biopsies from the affected dermatomes of 35 adult patients with herpes zoster in the acute phase and 3 months post-treatment, using protein gene product 9.5 immunohistochemistry. In contrast to the significant increase in subepidermal nerve fibre density (11.77 ± 4.88/mm vs. 13.29 ± 5.74/ mm, p = 0.045) after 3 months, no differences were found in epidermal free nerve endings (2.43 ± 2.35/mm and 2.8 ± 2.86/mm, p = 0.168). Patients with post-herpetic neuralgia had significantly lower subepidermal nerve fibre densities (9.7 ± 2.05/mm vs. 14.72 ± 6.13/mm, p = 0.011) compared to with non-post-herpetic neuralgia patients. No differences in cutaneous nerve density were found in relation to antiviral therapy. In conclusion, 3 months after acute infection, no sign of epidermal innervation recovery is observed, while the increased subepidermal nerve fibre density in the affected dermatomes probably reflects nerve regeneration that is not affected by antiviral agent type. Subepidermal nerve fibre density is decreased in patients with post-herpetic neuralgia 3-months post-acute herpes zoster infection. © 2014 The Authors

Building energy management systems in building’s retrofit using power lines

Summarization: The aim of the specific paper is the analysis of the efficiency of power lines as a communication media for Building Energy Management Systems. The reason behind this scope is the ability of power lines to be installed in existing buildings without extra wiring. Building Energy Management Systems (BEMS) constitute a part of automation systems. BEMS implement control the indoor environmental parameters while minimizing energy consumption. This work aims to analyze the ability of installing Building Energy Management Systems (BEMS) in any building while simultaneously improve the energy efficiency and the indoor comfort. The easiest and most economic way to construct a BEMS in an existing building is to use the existing technologies of the building. These are power lines and Local Area Networks (LANs). Another way to develop and implement BEMS is radio frequencies (RF). These technologies can be used to existing buildings because they need no wiring and the installation cost is very small. Before choosing the devices that will formulate the BEMS, the parameters that affect the indoor conditions must be determined. Those are thermal comfort, visual comfort, indoor air quality and acoustic comfort. In order to check the efficiency of communication protocols that use power lines as a mean to communicate, a test installation is implemented in laboratory. This installation is performed via two development kits: the Power Line Development Support Kit (PL DSK) and Mini Evaluation Kit (Mini EVK). The test included a temperature sensor as a controlled variable and a decentralised heating control system with a central heating unit for the control signal. The results of the testing as well as specifications for installation in existing buildings are described focusing on disseminating such technologies in meeting the continuously increasing energy demands of the buildings in Crete, GreeceΠαρουσιάστηκε στο: 2nd International Conference on Passive and Low Energy Coolin

Native-immigrant wage differentials and occupational segregation in the Greek labour market

This article explores native-immigrant wage differentials in the Greek labour market. Data from the most recent Greek Household Budget Survey (2004-05) were employed, four alternative occupational categories were considered and occupational choice was explicitly modelled. Controlling for occupational selectivity, occupation-specific wage regressions for representative samples of employed native and immigrant workers were estimated and an augmented decomposition technique was utilized to analyse inter and intra occupation wage differentials. The obtained results demonstrate that roughly 48% of the average wage differential cannot be explained by differences in observed characteristics and that the larger component of this unexplained part is due to asymmetrical occupational access by native and immigrant workers.