Dynamic thermal models: reliability for domestic building design

This paper describes a three year UK initiative—Applicability Study 1-to enhance the usability and credibility of detailed thermal simulation programs with particular reference. to the design of passive solar dwellings. Researchers at Leicester Polytechnic and the Building Research Establishment are working with ESP, HTB2 and SERIRES. The aims are to identify the problems for which these programs can be used reliably and those for which they cannot, to provide guidance on the best modelling techniques, indicate the uncertainty inherent in predictions, identify the attributes of programs which are necessary to obtain reliable results, and indicate areas in which additional theoretical or experimental research is needed. The results to date show that good agreement in some design trends can be obtained provided a high level of quality control is exercised and program users have a good understanding of the theoretical basis of the programs. There were, however, some situations in which the programs still predicted significant differences in the trends in energy consumption as the building design changed. These may be explained by the different algorithms employed by the detailed thermal simulation programs and errors in them

Occurrence, potential sources, in vitro bioaccessibility and health risk assessment of heavy metal in indoor dust from different microenvironment of Bushehr, Iran

Indoor dust samples were collected from 42 microenvironments of residential buildings (RB, 15 samples), official buildings (OB, 10 samples), laboratory rooms (LR, 7 samples), and school classroom (SCR, 10 samples) in Bushehr, whereby the concentration of zinc, copper, lead, cadmium, nickel, and chromium was studied. The results of this study indicated that the mean concentrations of Zn, Cu, Pb, Cd, Cr, and Ni in the indoor dust samples were 567.18, 186.09, 209.01, 5.31, 143.20, and 57.09 mg/kg in RB, 1077.34, 539.67, 274.89, 8.12, 155.30, and 92.55 mg/kg in OB, 246.40, 149.56, 127.2, 1.96, 43.45, and 91.09 mg/kg in LR and 271.43, 189.84, 164.44, 3.06, 124.20, and 70.09 mg/kg in SCR. The results of principal cluster analysis showed that the heavy metals in indoor environments were mostly originated from smoking tobacco and cigarette, traffic sources, old building materials, and building paint colors. The results of this study also revealed that the concentration of heavy metals in indoor dust had a negative and significant relationship (P value < 0.05 in most cases) with rate of ventilation, and a positive and significant relationship with smoking inside buildings (P value < 0.05 in most cases). The bioaccessibility for zinc, copper, lead, cadmium, nickel, and chromium was 69.12, 40.08, 43.33, 79.81, 31.10, and 6.31%, respectively, in indoor dust. Further, risk assessment showed that the risk values of carcinogenicity and non-carcinogenicity resulting from heavy metals inside the studied microenvironments had exceeded the recommended safe limit by EPA. In terms of potential ecological risks, it was found that heavy metals in these microenvironments have exceeded the hazardous ecological levels presented by different indices and can have considerable negative ecological effects. Thus, it is essential that further and better studies and monitoring be performed on these environments, and suitable control recommendations and solutions should be regulated for this public health threat

Solar energy utilisation and evacuated tubular solar collectors

SIGLEAvailable from British Library Document Supply Centre- DSC:DX95894 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Positive Emotions from Brain Injury: The Emergence of Mirth and Happiness

Brain injury can result in an increase in positive emotions. We describe a 63-year-old man who presented with a prominent personality change after a gunshot wound to the head. He became “content,” light-hearted, and prone to joking and punning. Prior to his brain injury, he suffered from frequent depression and suicidal ideation, which subsequently resolved. Examination showed a large right calvarial defect and right facial weakness, along with memory impairment and variable executive functions. Further testing was notable for excellent performance on joke comprehension, good facial emotional recognition, adequate Theory of Mind, and elevated happiness. Neuroimaging revealed loss of much of the right frontal and right anterior lobes and left orbitofrontal injury. This patient, and the literature, suggests that frontal predominant injury can facilitate the emergence of mirth along with a sense of increased happiness possibly from disinhibited activation of the subcortical reward/pleasure centers of the ventral striatal limbic area

Cellular tracked optical wireless demonstration link

Line-of-sight optical wireless systems have the potential to provide extremely high bandwidth communications; the major problem is to ensure that a link can be maintained as transmitter and receiver more relative to one another, and to provide wide area coverage. Cellular systems, or tracking systems that incorporate multiple sources and detectors, have the potential to achieve high bandwidth and provide the necessary area coverage. In the paper, the construction and testing of a cellular tracked demonstration optical wireless link that empl'oys a 3 × 3 array of vertical-cavity surface-emitting lasers in the transmitter and a 3 × 3 array of silicon photodiodes in the receiver is reported. The link operates at 32.77 Mbit/s and is demonstrated to provide coverage to a BER of 1 × 10-9 across an area of 0.8 m × 0.8 m at a link distance of 2.5 m. This is believed to be the first reported cellular tracked link that demonstrates tracking in two dimensions. Consideration is given to extending the coverage area of the link

An optical wireless test-bed system using a multiple source transmitter and a segmented receiver to achieve signal tracking

With ever increasing requirements for bandwidth in communications and the trend towards the use of wireless technologies for increased mobility and convenience, greater interest is being directed towards optical wireless as a potential alternative to radio for some applications. Differing link architectures have been proposed for various purposes; diffuse systems for maximum mobility and narrow line-of-sight systems when bandwidth is of greatest importance. The use of a transmitting antenna consisting of more than one optical source can mitigate some of the disadvantages of both line-of-sight and diffuse systems. Each source illuminates a coverage cell, providing greater coverage area than a line-of-sight system and no requirement for pointing, whilst also retaining the potential for higher bandwidths than a diffuse system. The use of a segmented receiver, on the other hand, results in a reduced photodiode capacitance penalty and, due to the possibility of signal processing on the multiple received signals, the potential for improved gain. In this paper we present a test-bed system that incorporates features of both the diffuse and line-of-sight architectures by employing multi-element transmitter and receiver structures. We demonstrate that the combination of such a transmitter and receiver, in conjunction with some focusing optics can provide information about direction of signal arrival, allowing tracking of the optical signal

A cellular optical wireless system demonstrator

The features of a cellular optical wireless link employing a multi-element receiver and transmitter was discussed. The receiver structure takes receiving signals to achieve a high optical gain and wide field-of-view to realize solid-state tracking. The receiver is AC coupled for rejection of ambient light noise and uses it for reducing baseline wander. The system is able to track the transmitter beam as the receiver moves in two dimensions across the coverage area of the transmitter

Electronic tagging and wireless technologies An overview

Title from coverAvailable from British Library Document Supply Centre- DSC:2277. 485(16/02 pt 2) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo