29 research outputs found
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
Increased Density of Cutaneous Nerve Fibres in the Affected Dermatomes After Herpes Zoster Therapy
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
flEECe, an energy use and occupant behavior dataset for net-zero energy affordable senior residential buildings
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.