COMPARING THE PRIVACY VS DAYLIGHT COMPROMISE FOR DIFFERENT WINDOW COVERINGS

Cultural factors in Libya (and other Muslim countries) require female privacy to be maintained. Outside the home, females must wear clothing that reveals only the face and hands. When inside the home and located near windows, a similar degree of clothing cover, or, window screening, is required. This reduces exposure to natural daylight, with resultant reduction in health benefits of daylight. We are therefore investigating the degree to which window privacy devices offer sufficient privacy to permit relaxed clothing in the home, and whether this leads to an increased daylight exposure. Two window coverings were tested, horizontal blinds and frosted glass, varying the free area and degree of frosting respectively. The degree of privacy offered was operationalised by identification of the clothing level worn by a target behind the window screen, the aim being to reduce this to a chance level. For horizontal blinds, the free area must be reduced to 3% to maintain sufficient privacy, which is unlikely to permit sufficient daylight to offset the wearing of relaxed clothing. While a high degree of frosting is required for a similar level of privacy, this may permit more daylight.

Two-stage window screening and development trajectories in early identification of autism spectrum disorder among Han Chinese children

Objective An understanding of the trajectory and norm of development in children is needed in order to understand the concept of the spectrum in the diagnosis of autism spectrum disorder (ASD). Children’s developmental growth trajectory was measured from six to 66 months in the Taiwan Birth Cohort Study dataset (N = 11,145). Additionally, over 4 years of follow-up, the negative predictive value of using the Parental Concern Checklist and Taiwan Birth Cohort Study Developmental Instrument was also investigated as the first stage of screening in a two-stage window screening method for ASD diagnosis. Results The growth trajectory showed that children’s language development began to increase at 18 months, and peaked at 36 months. On the other hand, social development showed steady growth from 18 to 66 months. The increase in the trajectory of children’s language development prior to age three, when compared with other developmental dimensions, may increase the difficulty of diagnosing ASD. The two-stage window screening method can be used in settings where the screening sample is large, such as in community or primary care settings, and has been found to be time- and cost-efficient. Better understanding of children’s developmental trajectory can enhance detection and intervention for ASD.

A Computational Fluid Dynamics Study on the Effect of Carbon Particle Seeding for the Improvement of Solar Reactor Performance

This study focuses on a technique, referred to as “solar cracking” of natural gas for the coproduction of hydrogen and carbon as byproduct with zero emission footprint. Seeding a solar reactor with micron-sized carbon particles increases the conversion efficiency drastically due to the radiation absorbed by the carbon particles and additional nucleation sites formed by carbon particles for heterogeneous decomposition reaction. The present study numerically tries to investigate the above fact by tracking carbon particles in a Lagrangian framework. The results on the effect of particle loading, particle emissivity, injection point location, and effect of using different window screening gases on a flow and temperature distribution inside a confined tornado flow reactor are presented.

The Tornado Flow Configuration—An Effective Method for Screening of a Solar Reactor Window

The working fluid in solar receivers, utilized for effecting chemical reactions, is usually flown through a sealed enclosure provided with a quartz window. When one of the reactants or products of reaction is a powder, care must be taken to prevent contact of the incandescent powder particles with the window, in order to obviate its destruction by overheating. Attempts made in the past to screen the window against particle deposition by a “curtain” of an auxiliary gas stream showed that very substantial flow rates of auxiliary gas (30—80% of the main stream flow rate) were necessary for perfect window screening. The heat absorbed by the auxiliary gas stream represented a major loss of energy. In an effort to reduce the auxiliary stream flow rate to a minimum, a certain flow pattern akin to the natural tornado phenomenon has recently been developed in our laboratory. It enabled effective reactor window screening by an auxiliary gas flow rate less than 5% of the main gas flow rate. The tornado effect is discussed and demonstrated by a smoke flow visualization technique.

The role of the Douglas-fir beetle and wood borers in the decomposition of and nutrient release from Douglas-fir logs

The role of insects in the decomposition of and nutrient release from Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) logs was studied in the Cedar River Watershed near Seattle, Washington. In April 1976, two large-diameter (average diameter at breast height, 41.7 cm) and two small-diameter (average diameter at breast height 26.3 cm) trees were felled. Three pairs of 91 cm length sections were cut from each tree. Half the sections were covered with window screening to prevent insect entry. The number of Douglas-fir beetle (Dendroctonuspseudotsugae Hpk.) attacks on each section, as well as the frass production, were monitored. After 10 years, decomposition rates were determined by mass loss. Douglas-fir beetles attacked large-diameter (23 attacks/m2) and small-diameter (27 attacks/m2) log sections at similar rates. Total frass production was also similar (33.6 g•m−2 for large logs and 32.6 g•m−2 for small logs). Large-diameter unscreened log sections tended to decompose faster (k = 0.050 per year) than small diameter unscreened logs (k = 0.026 per year) owing to the presence of wood borers (Monochamusscutellatus (Say)) in the larger logs. Screening of logs to reduce insect attack tended to reduce the rate of decomposition. A brown rotting fungus (Oligoporusplacentus (Fr.) Gilb. and Ryv.) fruited on unscreened large-diameter logs. Wood borers had a greater influence on log decomposition than Douglas-fir beetles. Frass produced by the Douglas-fir beetle contributed very little to litter fall and nutrient cycling. After 10 years there was a net release of N, P, K, Ca, and Mn from decomposing logs. Only Mg was immobilized in large-diameter logs.

Some factors influencing vision through meshes

The problem of designing window screening devices involves the optimization of several conflicting environmental requirements for which few data exist on the aspect of outward vision. Three experiments are described in which the vision obstructing characteristics of a mesh-screening material are investigated. Experiment 1 shows the relevance, in a field situation, of employing a factorial design. Experiment 2 used a one-eighth replicate 2 11 factorial design to determine the more significant variables and first order interactions responsible for limiting vision through a mesh. The measurement of visual acuity and the technique of ratio scaling were used to record visibility. Visual task luminance was selected for further study in experiment 3 where Stevens’ power law was established between direct magnitude estimates of ‘ease of seeing’ and visual acuity scores. It is suggested that this technique be extended to scale the effects on visibility of a number of the other variables thus making possible the total functional and cost optimization of window screening materials.