1,128,406 research outputs found
Sensitivity of night cooling performance to room/system design: surrogate models based on CFD
Night cooling, especially in offices, attracts growing interest. Unfortunately, building designers face considerable problems with the case-specific convective heat transfer by night. The BES programs they use actually need extra input, from either costly experiments or CFD simulations. Alternatively, up-front research on how to engineer best a generic night cooled office â as in this work â can thrust the application of night cooling. A fully automated configuration of data sampling, geometry/grid generation, CFD solving and surrogate modelling, generates several surrogate models. These models relate the convective heat flow in a night cooled landscape office to the ventilation concept, mass distribution, geometry and driving force for convective heat transfer. The results indicate that cases with a thermally massive floor have the highest night cooling performance
Night-time accidents: a scoping study. Report to The AA Motoring Trust and Rees Jeffreys Road Fund
Context:
Only a quarter of all travel by car drivers is undertaken between the hours of
19.00 and 08.00, but it is in this period that 40 percent of fatal and serious
injuries are sustained by drivers. This indicates that car travel at night carries a
greater risk of being killed or seriously injured than does travel during the day.
The literature indicates that disproportionate numbers of young drivers,
especially young men, are injured at night. But to be able to introduce
measures targeted at this group more needs to be known about the purpose of
their journeys, the types of roads they travel on, and how far they drive and at
what times in the evening and at night.
Older drivers tend to have fewer accidents at night, but little is currently known
about how much can be accounted for by exposure related to their driving
patterns. People over the age of 60 years form about 20 percent of the
population, yet they make up over a quarter of traffic fatalities.
These two groups of young and older drivers have been selected for study with
the following aims:
(a) to assess what information exists which relates to night-time exposure by
activity and by group (young and older);
(b) to assess what is known about exposure and risk to young and older drivers
at night, in conjunction with an analysis of relevant accident data to provide a
picture of the size of the potential problem areas, and gaps in current
knowledge;
(c) to identify peopleâs concerns, attitudes and beliefs with regard to the
problems of night-time driving; and
(d) to provide the basis for decision on what measures might be brought to bear
on the problem, and what further research would be needed in order to point to
focused action.
This scoping study is in two parts and provides an assessment of the
information available and hence the gaps in our knowledge on the nature and
extent of night-time driving, and the risks involved at these times. The first
part assesses the available data, and the second uses focus groups to gather the
views of drivers themselves, together with their concerns, attitudes and beliefs
with regard to the problems of night-time driving.
The measurement of exposure, or amount of travel by car, of drivers of
different age and gender is central to the assessment of the risk of being killed
or injured in a road traffic accident. In this study, the measure of exposure used
is distance travelled per person per year. This has been combined with casualty
data to make preliminary assessments of risk to people of different ages and
gender of driving at during the daytime and at night
Differences in Dolphin Mortality Rates in Night and Day Sets for the U.S. Eastern Tropical Pacific Tuna Purse Seine Fishery
Because dolphins sometimes travel with yellowfin tuna, Thunnus albacares, in the eastern tropical Pacific (ETP), purse seiners use the dolphins to locate and capture tuna schools. During the process of setting the purse seine nets, dolphins often become entangled and drown before they can be released. Data for the U.S. purse seine fleet in the ETP during 1979-88 show that dolphin mortality rates in sets made during the night are higher than mortality rates in sets made during the day. Even with efforts to reduce nightset mortality rates through the use of high intensity floodlights, night set mortality rates remain higher. The data are also used to simulate a regulation on the fishery aimed at eliminating night sets and show that dolphin mortality rates would decrease
You Canât âNudgeâ Nuggets: An Investigation of Late Night Dining With Behavioral Economics Interventions
A mixed-methods approach was used to evaluate and improve the âLate-Night Diningâ options in a university dining hall. Surveys assessed student desires around Late-Night offerings, and evaluated studentsâ habits and motivations during Late-Night. Two interventions based on the principles of behavioral economics were implemented to see if students could be ânudgedâ into making healthier choices. In the first, a âveggie-heavyâ entrĂ©e was added at the beginning of the entrĂ©e line, so that students would substitute a healthier entrĂ©e for the less healthy alternatives. In the second, a healthy snack-food bar was set up to cater to students who didnât want to stand in the long entrĂ©e line. Data on food choice was collected during the interventions.
Survey responses showed significant differences in the reasons females and males utilized Late-Night Dining (p
Following our interventions, Dining Services continued to offer the healthy snack bar, and veggie-heavy entrées were included in the rotation of Late-Night entrée options
Constraints on neutrino oscillation parameters from the measurement of day-night solar neutrino fluxes at Super-Kamiokande
A search for day-night variations in the solar neutrino flux resulting from
neutrino oscillations has been carried out using the 504 day sample of solar
neutrino data obtained at Super-Kamiokande. The absence of a significant
day-night variation has set an absolute flux independent exclusion region in
the two neutrino oscillation parameter space.Comment: 11 pages, 3 figures, submitted to PRL, single-spacin
Photometric monitoring of the blazar 3C 345 for the period 1996 - 2006
We present the results of the blazar 3C 345 monitoring in Johnson-Cousins
BVRI bands for the period 1996 - 2006. We have collected 29 V and 43 R data
points for this period; the BI light curves contain a few measurements only.
The accuracy of our photometry is not better than 0.03 mag in the VR bands. The
total amplitude of the variability obtained from our data is 2.06 mag in the V
band and 2.25 mag in the R one. 3C 345 showed periods of flaring activity
during 1998/99 and 2001: a maximum of the blazar brightness was detected in
2001 February - 15.345 mag in the V band and 14.944 mag in the R one. We
confirm that during brighter stages 3C 345 becomes redder; for higher fluxes
the colour index seems to be less dependent on the magnitude. The intra-night
monitoring of 3C 345 in three consecutive nights in 2001 August revealed no
significant intra-night variability; 3C 345 did not show evident flux changes
over timescales of weeks around the period of the intra-night monitoring. This
result supports the existing facts that intra-night variability is correlated
with rapid flux changes rather than with specific flux levels
Using all-sky differential photometry to investigate how nocturnal clouds darken the night sky in rural areas
Artificial light at night has affected most of the natural nocturnal
landscapes worldwide and the subsequent light pollution has diverse effects on
flora, fauna and human well-being. To evaluate the environmental impacts of
light pollution, it is crucial to understand both the natural and artificial
components of light at night under all weather conditions. The night sky
brightness for clear skies is relatively well understood and a reference point
for a lower limit is defined. However, no such reference point exists for
cloudy skies. While some studies have examined the brightening of the night sky
by clouds in urban areas, the published data on the (natural) darkening by
clouds is very sparse. Knowledge of reference points for the illumination of
natural nocturnal environments however, is essential for experimental design
and ecological modeling to assess the impacts of light pollution. Here we use
differential all-sky photometry with a commercial digital camera to investigate
how clouds darken sky brightness at two rural sites. The spatially resolved
data enables us to identify and study the nearly unpolluted parts of the sky
and to set an upper limit on ground illumination for overcast nights at sites
without light pollution.Comment: 17 pages, 6 figure
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