859 research outputs found
The importance of sample grouping; Exploring thermal sensitivity of occupants within one building type and ventilation mode
Occupantsâ thermal response is influenced by their sensitivity to temperature variations, i.e. the rate of change in occupantsâ thermal sensation per unit change in indoor temperature. Thermal sensitivity is commonly taken as constant (Griffiths constant) in the calculation of occupantsâ comfort temperature. This constant is based on small differences found between buildingsâ ventilation modes [naturally ventilated (NV) vs. air conditioned (AC)]. However, recent research found significant differences depending on building type, ventilation mode, age, gender and climate. This paper reviews thermal sensitivity within the same building type and main ventilation mode using longitudinal surveys and monitoring data from school buildings, two in the UK (U1 and U2) and one in Sweden (S1). Results show that in two of the schools (U1 and S1) children were half as sensitive as in school U2 and the difference is statistically significant. A similar result with slightly different thermal sensitivities was derived from comparison by clusters derived from the classroomsâ indoor temperatures. This outcome suggests that building ventilation mode (AC/NV), which is typically considered the main determinant of occupantsâ thermal experience and often the only building information recorded in field surveys, is inadequate to explain this important occupant response factor
A Control Architecture for Entanglement Generation Switches in Quantum Networks
Entanglement between quantum network nodes is often produced using
intermediary devices - such as heralding stations - as a resource. When scaling
quantum networks to many nodes, requiring a dedicated intermediary device for
every pair of nodes introduces high costs. Here, we propose a cost-effective
architecture to connect many quantum network nodes via a central quantum
network hub called an Entanglement Generation Switch (EGS). The EGS allows
multiple quantum nodes to be connected at a fixed resource cost, by sharing the
resources needed to make entanglement. We propose an algorithm called the Rate
Control Protocol (RCP) which moderates the level of competition for access to
the hub's resources between sets of users. We proceed to prove a convergence
theorem for rates yielded by the algorithm. To derive the algorithm we work in
the framework of Network Utility Maximization (NUM) and make use of the theory
of Lagrange multipliers and Lagrangian duality. Our EGS architecture lays the
groundwork for developing control architectures compatible with other types of
quantum network hubs as well as system models of greater complexity
Occupancy Patterns Scoping Review Project
Understanding the occupancy and heating patterns of UK domestic consumers is important for understanding the role of demand-side technologies, such as occupancy-based smart heating controls to manage energy consumption more efficiently.The research undertakes a systematic scoping review to identify and assess the quality of the UK and international evidence on occupancy patterns, to critically review the common methods of measuring occupancy, and to discuss the potential role of occupancy-based smart heating controls in meeting energy savings, thermal comfort and usability requirements.This report was prepared by a team at the University of Southampton and commissioned by the former Department of Energy and Climate Change (DECC).<br/
Saving energy through changing light: The impact of illumination on thermal comfort
The âHue-Heat Hypothesisâ states that light with wavelengths predominantly at the red end of the spectrum (or of a low colour temperature) are felt as warmer, whilst light with wavelengths mainly in the blue end (or of a high colour temperature) are felt as cooler. If confirmed, the Hue-Heat-Hypothesis could be a powerful tool for energy savings: Temperatures could be lowered under a reddish light in the heating season. Conversely, less air-conditioning might be needed during the cooling season if higher temperatures were accepted under a bluish light. Even a transitory effect would be beneficial in managing power demand by allowing building temperatures to drift over a wider range of temperatures before heating or cooling was required.
We used an experimental design to study the Hue-Heat-Hypothesis. Testing took place in a climate chamber, in which ambient temperature, relative humidity, and air speed can be controlled. We installed a LED-lighting system in the chamber covering the range of correlated colour temperatures from 2700K, a warm, reddish light, to 6500K which appears bluish-cold. Participants (age range 18 to 35 years) were exposed to combinations of colour temperature and ambient temperature and completed standard thermal comfort surveys at specific time-points. Prior to testing, participants filled in a survey that asked about other factors potentially impacting on thermal comfort.
In Study 1, temperature in the climate chamber was cooled continuously from 24°C to 20°C over a 60-minute period. Comfort ratings were obtained every 10 minutes. Participants (N = 32) were either exposed to a colour temperature of 2700K or 6500K (between-subjects design). Thermal comfort was higher under the warm colour temperature (2700K) than under the cold one (6500K). This difference was particularly pronounced for temperatures around 21 and 22°C. For the same subjective thermal comfort rating, ambient temperatures differed by around half a degree under the different lighting conditions. The magnitude of the effect varied with temperature (greatest effects observed around 22-23ËC) and by comfort question asked.
In Study 2, a within-subject design was used. Subjects were exposed to three different lights (2700K, 4440K,6500 K) with temperature decreasing from 23°C to 19°C. Preliminary results were similar to those of Study 1 with higher comfort under the warm-appearing light. Comfort ratings under the medium colour temperature of 4400K were positioned between the higher ratings obtained for 2700K and lower ratings for 6500K, again, only in a limited corridor of ambient temperature.
In Study 3, light was changed gradually from a cold to a warm colour temperature whilst ambient temperature decreased from 23°C to 19°C. Testing is on-going, but initial results indicate that the changes in self-reported comfort under decreasing temperatures are slower in the condition of changing light dynamically than under a stable
Our studies support the Hue-Heat-Hypothesis. Varying the ambient light has an effect on thermal comfort and hence may be a suitable tool for energy savings and reducing of peak power demand
Corrigendum: Characterization of a Novel Transitional Group \u3ci\u3eRickettsia\u3c/i\u3e Species (\u3ci\u3eRickettsia tillamookensis\u3c/i\u3e sp. nov.) from the Western Black-Legged Tick, \u3ci\u3eIxodes pacificus\u3c/i\u3e
Complete Genome Sequence of \u3ci\u3eRickettsia parkeri\u3c/i\u3e Strain Black Gap
A unique genotype of Rickettsia parkeri, designated R. parkeri strain Black Gap, has thus far been associated exclusively with the North American tick, Dermacentor parumapertus. The compete genome consists of a single circular chromosome with 1,329,522âbp and a G+C content of 32.5%
Sources, behaviour and mitigation strategies influencing indoor air quality
The particulate impact on air quality of typical domestic behaviours (e.g. cleaning and cooking) and their potential mitigation strategies (e.g. increasing ventilation) was investigated in the DOMESTIC unit at University of Chester. A 'typical day' based on the UK Time Use Survey of 2014-15 and tested under 2 separate ventilation conditions for 2 days each. This clearly indicated the impacts of different activities and the reduction of particulate levels with higher ventilation
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