WorldWideScience

Sample records for daylight

  1. Daylight Science and Daylighting Technology

    CERN Document Server

    Kittler, Richard; Darula, Stanislav

    2012-01-01

    Sunlight profoundly influences the Earth's atmosphere and biosphere. Nature fuels the evolution of all living things, their visual systems, and the manner in which they adapt, accommodate, and habituate. Sun luminance measurements serve as data to calculate typical changes in the daily, monthly, and annual variability characteristics of daylight. Climate-based sky luminance patterns are used as models in predicting daylighting calculation and computer programs applied in architecture and building design. Historically, daylight science and daylighting technology has prioritized photometric methods of measurements, calculation, and graphical tools aimed at predicting or evaluating the daylighting of architectural design alternatives. However, due to a heightened awareness of general health and well-being, sunlight exposure and freedom from visual discomfort while undertaking visual tasks are now equally prioritized. Therefore, in order to assure optimal environmental quality, daylighting technology must be base...

  2. Daylight calculations in practice

    DEFF Research Database (Denmark)

    Iversen, Anne; Roy, Nicolas; Hvass, Mette

    The aim of the project was to obtain a better understanding of what daylight calculations show and also to gain knowledge of how the different daylight simulation programs perform compared with each other. Experience has shown that results for the same room, obtained from two daylight simulation...... programs can give different results. This can be due to restrictions in the program itself and/or be due to the skills of the persons setting up the models. This is crucial as daylight calculations are used to document that the demands and recommendations to daylight levels outlined by building authorities....... The aim of the project was to obtain a better understanding of what daylight calculations show and also to gain knowledge of how the different daylight simulation programs perform compared with each other. Furthermore the aim was to provide knowledge of how to build up the 3D models that were...

  3. Capturing the Daylight Dividend

    Energy Technology Data Exchange (ETDEWEB)

    Peter Boyce; Claudia Hunter; Owen Howlett

    2006-04-30

    Capturing the Daylight Dividend conducted activities to build market demand for daylight as a means of improving indoor environmental quality, overcoming technological barriers to effective daylighting, and informing and assisting state and regional market transformation and resource acquisition program implementation efforts. The program clarified the benefits of daylight by examining whole building systems energy interactions between windows, lighting, heating, and air conditioning in daylit buildings, and daylighting's effect on the human circadian system and productivity. The project undertook work to advance photosensors, dimming systems, and ballasts, and provided technical training in specifying and operating daylighting controls in buildings. Future daylighting work is recommended in metric development, technology development, testing, training, education, and outreach.

  4. Rethinking daylighting and compliance

    Directory of Open Access Journals (Sweden)

    John Mardaljevic

    2013-10-01

    Full Text Available Daylight in buildings is the natural illumination experienced by the occupants of any man-made construction with openings to the outside. Our attempts to formulate some measure of daylight provision in buildings can be traced back over a century, and the daylight factor as we know it today is over 50 years old. Still the most common measure found in guidelines and recommendations worldwide, the daylight factor is used routinely and, it is fair to say, often rather uncritically. The consideration of daylight in buildings has received a new impetus from the accumulation of evidence on the wider benefits of daylight exposure. But it is continuing to prove difficult to advance beyond daylight factors towards a more realistic quantification of daylighting performance that would allow us to accommodate these new considerations in an evaluative schema. This paper examines the basis of current practice with respect to daylight evaluation, and suggests a few ways in which it can be improved with relatively modest additional effort. The paper also critiques some of the recent attempts to advance daylight evaluation by incremental means using so-called “clear sky options”.

  5. Daylight utilisation in office buildings

    DEFF Research Database (Denmark)

    Christoffersen, Jens

    This Ph.D. thesis presents the qualitative and quantitative consequences of full-scale measurements on two daylighting systems, light shelf and Venetian blinds. The systems were investigated to assess their ability to increase daylight penetration and improve daylight distribution in the interior...... the benefits and difficulties regarding use of daylight in office buildings, but it is hoped that the report will provide daylight conscious building design in forthcoming non-domestic buil dings....

  6. ADASY (Active Daylighting System)

    Science.gov (United States)

    Vázquez-Moliní, Daniel; González-Montes, Mario; Fernández-Balbuena, Antonio Á.; Bernabéu, Eusebio; García-Botella, Ángel; García-Rodríguez, Lucas; Pohl, Wilfried

    2009-08-01

    The main objective of ADASY (Active Daylighting System) work is to design a façade static daylighting system oriented to office applications, mainly. The goal of the project is to save energy by guiding daylight into a building for lighting purpose. With this approach we can reduce the electrical load for artificial lighting, completing it with sustainable energy. The collector of the system is integrated on a vertical façade and its distribution guide is always horizontal inside of the false ceiling. ADASY is designed with a specific patent pending caption system, a modular light-guide and light extractor luminaire system. Special care has been put on the final cost of the system and its building integration purpose. The current ADASY configuration is able to illuminate 40 m2 area with a 300lx-400lx level in the mid time work hours; furthermore it has a good enough spatial uniformity distribution and a controlled glare. The data presented in this study are the result of simulation models and have been confirmed by a physical scaled prototype. ADASY's main advantages over regular illumination systems are: -Low maintenance; it has not mobile pieces and therefore it lasts for a long time and require little attention once installed. - No energy consumption; solar light continue working even if there has been a power outage. - High quality of light: the colour rendering of light is very high - Psychological benefits: People working with daylight get less stress and more comfort, increasing productivity. - Health benefits

  7. Designing with daylight; the relationship between daylight and health

    DEFF Research Database (Denmark)

    Hauge, Bettina

    2015-01-01

    and the significance of daylight. This paper describes the views and significance of daylight to people in their everyday lives. Based on a qualitative research project in Denmark about the use of windows, performed from May to August 2012 among 13 families , using in-depth interviews, observations, photos...... and postcards for storytelling, I will show how daylight is perceived, used, coped with, and negotiated by these people in their homes, thus exploring the social character of a natural phenomenon. A metaphor will be used from biomimetics (Benyus 1997), claiming that the Danish people, like plants, need daylight....... With the concept of ‘dwelling’ (Ingold 2000), which implies that people engage in their environment and create possibilities for dwelling at home to feel comfortable and at home in the world, I illustrate people’s day-to-day entanglements with daylight and highlight the social qualities of daylight. The paper...

  8. Colour Mixing Based on Daylight

    Science.gov (United States)

    Meyn, Jan-Peter

    2008-01-01

    Colour science is based on the sensation of monochromatic light. In contrast to that, surface colours are caused by reflection of wide sections of the daylight spectrum. Non-spectral colours like magenta and purple appear homologous to colours with spectral hue, if the approach of mixing monochromatic light is abandoned. It is shown that a large…

  9. Advanced fenestration and daylighting systems

    Energy Technology Data Exchange (ETDEWEB)

    McCluney, R. [Florida Solar Energy Centere, Cocoa, FL (United States)

    1998-09-01

    Advanced fenestration systems are new high-performance glazing and reflecting systems for otherwise conventional windows which offer specialized spectral and /or angular selectivity to provide improved illumination quantity and quality under optimal human comfort and energy conservation conditions. Advanced daylighting systems include systems manufactured by the solar lighting industry to introduce daylight into the core spaces of multi-storey buildings, spaces distant from the building envelope, or other locations where more conventional daylighting apertures cannot be placed. Details of operating, energy and illumination performance characteristics of both these systems were provided. It was concluded that solar lighting systems can effectively provide daylight illumination to interior spaces of a building that are not amenable to more conventional systems. Nevertheless, techniques need to be developed to predict the performance of such systems prior to their being built, so as to provide designers better means for justifying their use and economic viability, and to develop codes and performance standards to protect the consumer in the marketplace. 20 refs., 12 figs.

  10. Lightpipe applications for daylighting systems

    NARCIS (Netherlands)

    Rosemann, A.; Kaase, H.

    One of the main research activities of the Institute of Lighting at Technical University of Berlin concerns efficient daylight utilisation in buildings. In recent years, several national and international projects have been and are still carried out. One of them, the European research project

  11. Daylight as a building material

    DEFF Research Database (Denmark)

    Thule Kristensen, Peter; Madsen, Merete

    2005-01-01

    The article draws on examples to chronologically trace the use of daylight as building material in architecture of the 20th and early 21st century. The essay covers works of Mies van der Rohe, Le Corbusier, Erik Bryggman, Rudolf Schwarz, Alvar Aalto, Aldo Rossi, Jørn Utzon, Daniel Libeskind, Peter...

  12. Daylight photodynamic therapy for actinic keratosis

    DEFF Research Database (Denmark)

    Wiegell, Stine; Wulf, H C; Szeimies, R-M

    2011-01-01

    clinic visits and discomfort during therapy. In this article, we critically review daylight-mediated PDT, which is a simpler and more tolerable treatment procedure for PDT. We review the effective light dose, efficacy and safety, the need for prior application of sunscreen, and potential clinical scope...... of daylight-PDT. Three randomized controlled studies have shown that daylight-mediated PDT is an effective treatment of thin AKs. Daylight-mediated PDT is nearly pain-free and more convenient for both the clinics and patients. Daylight-mediated PDT is especially suited for patients with large field......-cancerized areas, which can easily be exposed to daylight. Further investigations are necessary to determine at which time of the year and in which weather conditions daylight-mediated PDT will be possible in different geographical locations....

  13. Colour mixing based on daylight

    International Nuclear Information System (INIS)

    Meyn, Jan-Peter

    2008-01-01

    Colour science is based on the sensation of monochromatic light. In contrast to that, surface colours are caused by reflection of wide sections of the daylight spectrum. Non-spectral colours like magenta and purple appear homologous to colours with spectral hue, if the approach of mixing monochromatic light is abandoned. It is shown that a large region of the colour space can be covered by mixing three primary colours derived from lossless spectral decomposition of daylight. These primaries are specified by hue, saturation and luminosity. Duality of additive and subtractive mixing is formulated quantitatively. Experimental demonstrations of calculated results are suggested. This paper is intended for undergraduate optics courses, and advanced interdisciplinary seminars on arts and physics

  14. Light and energy - daylight measurements

    Energy Technology Data Exchange (ETDEWEB)

    Christoffersen, Jens; Logadottir, A.; Traberg-Borup, S.; Barrie-Nielsen, K.

    2009-07-01

    All measurements where conducted in the spring of 2007, except the Interpane panel. The solar cell panels have been evaluated by three performance indicators to assess the daylight quantity within the room and the systems ability to maintain view to the outside. In the study, we used two performance indicators to assess the daylight quantity within the room: 1. the daylight factor (overcast sky) 2. the relative work plane illuminance (clear sky condition) Overcast sky: In general, all panels provided less daylight than the recommended requirement in the Danish Building Regulation of 2% on the work plane. This will most likely result in additional need for electric lighting. However, larger window areas and more parts of the facade with clear unobstructed glass may be one solution. Clear sky: In general, all panels provided less interior light levels than the two reference systems in the back of the room. Almost all systems aloud more or less direct sunlight in the window perimeter through the clear openings and additional needs for some kind of shading device is to be expected. Some systems blocked a large portion of the light in the majority of the room, and additional electric light in this part of the room may be needed. Only one performance indicator where used to describe the quality of the panels. View: In general, all panels, except two, obstruct the view significantly and cause figure/background confusion for a view position close to the window and the discrepancies of colour judgements. Only two systems provided a fairly clear view to the outside without to much distortion of the view. (au)

  15. Daylighting, Space, and Architecture: A Literature Review

    Directory of Open Access Journals (Sweden)

    Dalia Hafiz

    2015-12-01

    Full Text Available Daylighting dynamism and constant change can characterize buildings and spaces with a living quality that cannot be achieved with any other design element. However, daylighting can create unwanted lighting conditions in the visual field causing discomfort and glare. This may affect the performance of building occupants such as workers or students. Consequently, designing for daylighting needs a good understanding of daylighting. Designers can rely on information from simulation software to re-imagine the space, especially to examine possible unexpected visual discomfort conditions.This paper aims to represent different visual comfort evaluation methods that can help decision-makers make better informed decisions. Different definitions and structures associated with daylight and glare are examined. It also presents a review of the literature of previous research conducted on daylighting, visual comfort analysis and glare studies.

  16. Daylight metrics and energy savings

    Energy Technology Data Exchange (ETDEWEB)

    Mardaljevic, John; Heschong, Lisa; Lee, Eleanor

    2009-12-31

    The drive towards sustainable, low-energy buildings has increased the need for simple, yet accurate methods to evaluate whether a daylit building meets minimum standards for energy and human comfort performance. Current metrics do not account for the temporal and spatial aspects of daylight, nor of occupants comfort or interventions. This paper reviews the historical basis of current compliance methods for achieving daylit buildings, proposes a technical basis for development of better metrics, and provides two case study examples to stimulate dialogue on how metrics can be applied in a practical, real-world context.

  17. Daylighting Strategies Promote Healthy High Performance Buildings

    Science.gov (United States)

    Gille, Steve

    2010-01-01

    There are many reasons to incorporate daylighting into the building or renovation of K-16 learning facilities. Benefits include increased productivity for students and staff, improved health, a better connection to the outdoors, energy savings and better quality of light. Add the role daylighting can play in LEED certification and it's clear that…

  18. Adaptive integration of daylight and artificial lighting

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve

    2016-01-01

    Daylight is dynamic and dependent upon weather conditions; unfolding with both subtle and dramatic variations in qualities of light. Through a building’s apertures, daylight creates a connection between the space inside and the world outside. The aperture or window itself constitutes the frame...... with the world. In contrast to fluctuating daylight, a specific distinctive feature of artificial light has been – until very recently – its constancy in colour and intensity. However, by virtue of the technological convertibility of LEDs in concert with digital control systems, LEDs are capable of dynamically...... producing variations in colour and intensity in ways that correspond to our experiences of the daylight. Daylight and artificial lighting are thus positioned in a new relationship to one another. Metaphorically, one can think of the adaptive software as ‘digital weather’ – as a self-generating and shifting...

  19. Evaluation of Daylight Availability for Energy Savings

    Directory of Open Access Journals (Sweden)

    Laura Bellia

    2015-06-01

    Full Text Available Dynamic daylight simulations are very useful instruments in daylighting design process. They allow an in depth analysis of indoor daylight availability levels and define if they are adequate to perform a particular visual task. Their results can be used to design shading devices or lighting control systems and compare different technical solutions. The use of these simulations is likely to spread in the common design practice since some regulations and green building rating systems suggest their use. This paper presents dynamic daylight simulation results related to an open-plan office, performed with Autodesk 3ds Max Design®, which is a calculation software validated by recent researches. It is not used in academic context but it is very widespread between technicians for photorenderings production purposes. The goal of this research is to demonstrate the functionality of this software also in dynamic daylight simulations field and propose an analysis' methodology to use it.

  20. Assessment of daylight quality in simple rooms

    DEFF Research Database (Denmark)

    Johnsen, Kjeld; Dubois, Marie-Claude; Sørensen, Karl Grau

    The present report documents the results of a study on daylight conditions in simple rooms of residential buildings. The overall objective of the study was to develop a basis for a method for the assessment of daylight quality in a room with simple geometry and window configurations. As a tool...... in daylighting conditions for a number of lighting parameters. The results gave clear indications of, for instance, which room would be the brightest, under which conditions might glare be a problem and which type of window would yield the greatest luminous variation (or visual interest), etc....

  1. Daylight and absenteeism--evidence from Norway.

    Science.gov (United States)

    Markussen, Simen; Røed, Knut

    2015-01-01

    Based on administrative register data from Norway, we examine the impact of hours of daylight on sick-leave absences among workers. Our preferred estimates imply that an additional hour of daylight increases the daily entry rate to absenteeism by 0.5 percent and the corresponding recovery rate by 0.8 percent, ceteris paribus. The overall relationship between absenteeism and daylight hours is negative. Absenteeism is also sensitive to weather conditions. Heavy snowfall raises the incidence of absence during the winter, while warm weather reduces the probability of returning to work during the summer. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Daylight calculations using constant luminance curves

    Energy Technology Data Exchange (ETDEWEB)

    Betman, E. [CRICYT, Mendoza (Argentina). Laboratorio de Ambiente Humano y Vivienda

    2005-02-01

    This paper presents a simple method to manually estimate daylight availability and to make daylight calculations using constant luminance curves calculated with local illuminance and irradiance data and the all-weather model for sky luminance distribution developed in the Atmospheric Science Research Center of the University of New York (ARSC) by Richard Perez et al. Work with constant luminance curves has the advantage that daylight calculations include the problem's directionality and preserve the information of the luminous climate of the place. This permits accurate knowledge of the resource and a strong basis to establish conclusions concerning topics related to the energy efficiency and comfort in buildings. The characteristics of the proposed method are compared with the method that uses the daylight factor. (author)

  3. Welcome to the Journal of Daylighting

    Directory of Open Access Journals (Sweden)

    Irfan Ullah

    2014-12-01

    Full Text Available I am delighted to welcome you to a newly launched Solarlits electronic journal: the Journal of Daylighting (JD. As the Editor-in-Chief of JD it is a great pleasure to introduce the inaugural issue of this new, open-access, bi-annual journal to readers, researchers, future authors, and colleagues. The decision by SolarLits to launch this new journal is very timely. Because the growth of lighting demand is increasing due to rising average illuminance levels in buildings, more attention has been paid to introduce daylighting in buildings, which will sustainably reduce the overall energy consumption in buildings. JD will serve as a new international platform for researchers to share advances in daylighting. As an international, peer-reviewed research journal it will exclusively cover the vibrant and diverse field of daylighting technologies and applications. JD will serve as an interdisciplinary forum for the scientific and research community active in daylighting and its applications. Topics will include, but not limited to: daylighting and hybrid lighting systems, lighting and daylighting simulation, lighting designs, lighting metrology and light quality, lighting control, building physics - lighting, building energy modeling, energy efficient buildings, zero-energy buildings, indoor environment quality, sustainable solar energy systems, application of solar energy sources in buildings, building-integrated photovoltaics, and solar thermal and concentrator technology. I will work with the Associate Editors, the Editorial Board, and the scientific and engineering research community to make JD a primary journal for the dissemination of breakthrough results, discussion of key challenges, and topics in daylighting. JD will publish full-length research articles, review articles, book reviews, and short communications.

  4. Modeling daylight from solar irradiation in Malaysia

    International Nuclear Information System (INIS)

    Ahmed, A.Z.; Sayigh, A.A.K.; Surendran, P.N.; Othman, M.Y.

    1999-01-01

    The oil crises in the seventies, the environmental impact by the extensive use of energy in the nineties and the recent economic recession in Asia have led to the rediscovery of the use of daylight in energy-conscious design in buildings, the economic implication of the excessive use of artificial lighting in potential of daylight. No daylight data is currently available in Malaysia and therefore there is a need to model the daylight availability based on other climatic parameters measured at meteorological stations. A study has been carried out to produce daylight data from measured climatic parameters, specifically solar irradiation and could cover. The Model Year Climate (MYC) data for the location of Subang (3 deg. 7', N 101 deg. 33' E), model to estimate daily diffuse irradiation was produced the average values of global (KG) and diffuse (KD) luminous efficacious were calculated and found to be 112 lm/W and 120 lm/W respectively. The value of 104 lm/W for the beam luminous efficacy (KB) was selected. Using cloud data cover data as input parameters, the nebulosity index was calculated to determine the sky condition in Subang, Malaysia, which was then classified as average or intermediate sky type, the hourly illuminance on horizontal and inclined surfaces at locations with similar sky conditions in Malaysia were then produced. (author)

  5. Comparative Study of Daylighting Calculation Methods

    Directory of Open Access Journals (Sweden)

    Mandala Ariani

    2018-01-01

    Full Text Available The aim of this study is to assess five daylighting calculation method commonly used in architectural study. The methods used include hand calculation methods (SNI/DPMB method and BRE Daylighting Protractors, scale models studied in an artificial sky simulator and computer programs using Dialux and Velux lighting software. The test room is conditioned by the uniform sky conditions, simple room geometry with variations of the room reflectance (black, grey, and white color. The analyses compared the result (including daylight factor, illumination, and coefficient of uniformity value and examines the similarity and contrast the result different. The color variations trial is used to analyses the internally reflection factor contribution to the result.

  6. THE CASE FOR DAYLIGHTING IN ARCHITECTURE

    Directory of Open Access Journals (Sweden)

    Barrett Richard

    2009-07-01

    Full Text Available The paper discusses the reasons for using daylight in the design of architectural form and space. These reasons extend from those of a practical nature, including energy conservation, cost factors, and health and wellbeing, to those of a more intangible, aesthetic nature. Some historical precedents are offered as examples of projects in which designing to maximize daylighting was crucial in the mind of the architect. By contrast there is also discussion relating to the ‘the lost art’ of using natural lighting in architecture. Some of the reasons for this loss of conviction and expertise are considered. The place of national building codes and other statutory requirements is examined, as is the role of the architect and his/her relationship with other professionals involved in daylighting design in architecture.

  7. A review of daylight illuminance determinations and energy implications

    Energy Technology Data Exchange (ETDEWEB)

    Li, Danny H.W. [Building Energy Research Group, Department of Building and Construction, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR (China)

    2010-07-15

    Daylighting is recognized as an important element in architecture and a useful strategy in energy-efficient building designs. Daylight gives a sense of cheeriness and brightness that can have a significant positive impact on the people. There is a scope for integrating daylight with electric light to reduce building energy use. The amount of daylight entering a building is mainly through window openings, which create in the indoor environment a more attractive and pleasing atmosphere, in addition to maximise visual access to the pleasant views of the outside world. Determinations of the exterior and interior daylight and lighting energy savings are key issues to demonstrate the benefits based on daylighting designs. This paper provides a review of daylight illuminance determinations and the lighting energy reductions due to daylighting schemes. The study includes daylight measurements, prediction of daylight illuminance under various sky conditions and potential electric lighting energy savings from daylight-linked lighting controls. The article aims at providing building professionals, practitioners and researchers more information and a better understanding of daylight for promoting effective daylighting designs and evaluations. (author)

  8. Workplane Illuminance Estimation for Robust Daylight Harvesting Lighting Control

    NARCIS (Netherlands)

    Zhang, S.; Birru, D.

    2012-01-01

    Daylight harvesting lighting controls can provide significant energysavings in daylit spaces. However, their performance is affected bythe changing lighting distribution in the space due to window treatments and the sun. Such impacts reduce the field performance of daylight harvesting dimming

  9. Weather conditions and daylight-mediated photodynamic therapy

    DEFF Research Database (Denmark)

    Wiegell, S R; Fabricius, S; Heydenreich, J

    2013-01-01

    Photodynamic therapy (PDT) is an attractive therapy for nonmelanoma skin cancers and actinic keratoses (AKs). Daylight-mediated methyl aminolaevulinate PDT (daylight-PDT) is a simple and painless treatment procedure for PDT. All daylight-PDT studies have been performed in the Nordic countries...

  10. Daylight prediction techniques in energy design tools

    Energy Technology Data Exchange (ETDEWEB)

    Milne, M.; Zurick, J. [California Univ., Los Angeles, Dept. of Architecture, CA (United States)

    1998-09-01

    Four different whole-building energy design tool systems that calculate energy savings from daylighting and that display annual performance on an-hour-by-hour basis, have been tested. The nature of design tools, the sources of hourly outdoor illuminance data, the ways of predicting indoor illumination, the assumptions of each tool, and the resulting energy savings of the design tools tested are discussed. The tests were carried out with the essential criteria for evaluating whole-building daylighting and energy design tools in mind. These have been identified as user confidence, accuracy, response time, and the amount of detail. Results of the tests, all four of them run on a single elementary school classroom for the sake of comparability, were provided. 9 refs., 2 figs.

  11. Daylighting simulation: methods, algorithms, and resources

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, William L.

    1999-12-01

    This document presents work conducted as part of Subtask C, ''Daylighting Design Tools'', Subgroup C2, ''New Daylight Algorithms'', of the IEA SHC Task 21 and the ECBCS Program Annex 29 ''Daylight in Buildings''. The search for and collection of daylighting analysis methods and algorithms led to two important observations. First, there is a wide range of needs for different types of methods to produce a complete analysis tool. These include: Geometry; Light modeling; Characterization of the natural illumination resource; Materials and components properties, representations; and Usability issues (interfaces, interoperability, representation of analysis results, etc). Second, very advantageously, there have been rapid advances in many basic methods in these areas, due to other forces. They are in part driven by: The commercial computer graphics community (commerce, entertainment); The lighting industry; Architectural rendering and visualization for projects; and Academia: Course materials, research. This has led to a very rich set of information resources that have direct applicability to the small daylighting analysis community. Furthermore, much of this information is in fact available online. Because much of the information about methods and algorithms is now online, an innovative reporting strategy was used: the core formats are electronic, and used to produce a printed form only secondarily. The electronic forms include both online WWW pages and a downloadable .PDF file with the same appearance and content. Both electronic forms include live primary and indirect links to actual information sources on the WWW. In most cases, little additional commentary is provided regarding the information links or citations that are provided. This in turn allows the report to be very concise. The links are expected speak for themselves. The report consists of only about 10+ pages, with about 100+ primary links, but

  12. Integration Issues for Using Innovative Daylighting Strategies in Light Wells

    Directory of Open Access Journals (Sweden)

    Gashinani M. Gholipour

    2017-12-01

    Full Text Available “Light well” as one of the most common means of daylight tolls in building, experiences severe limitations and deserve special attention. The question is which strategy is the best for increasing the daylight penetration to the depth of buildings. One of the main challenges in deep plan is to guide daylight into the building core and this can be performed through daylighting strategies, but the choice of the proper innovative daylighting system (IDS with several parameters is the problem. This paper aims to find elements for optimal choice and selecting context-compatible tools for light well. The result shows that four macro factors were found at the interaction of building and IDS. Identifying the integration components can play an effective role in decision-making or design a new tolls consistent with the physical conditions of light well and building to overcome the daylight crisis.

  13. Performance of a daylight-redirecting glass-shading system

    DEFF Research Database (Denmark)

    Appelfeld, David; Svendsen, Svend

    2013-01-01

    to the original system. The visual comfort was evaluated by glare analysis and the redirected daylight did not cause an additional discomfort glare. The higher utilization of daylight can save 20% of the lighting energy. The thermal insulation of the fenestration was maintained, with slightly increased solar......This paper evaluates the daylighting performance of a prototype external dynamic shading and daylight-redirecting system, and the main focus is on the performance simulation. The demonstration project was carried out on a building with an open-plan office. Part of the original façade was replaced...... with the prototype façade. This layout allowed the use of the same orientation and surroundings for both façades. The working plane illuminance was measured over several months and the measurements were accompanied with annual daylight simulations. The prototype system improved the daylighting conditions compared...

  14. Analysis of Daylight Control in a Chateau Interior

    Directory of Open Access Journals (Sweden)

    Jitka Mohelníková

    2018-05-01

    Full Text Available Assessment of daylighting in the residential hall of a historical chateau is presented. The evaluation is based on both the daylight measurement and simulations. Illuminance levels in the interior were controlled in accordance with requirements for light exposition of light sensitive materials. Valuable paintings and claddings as well as wallpapers and furniture upholstery in the hall are extremely light sensitive and they need to be protected from light damage. The daylight measurements and simulations give an overview of daylight conditions in the annual profile for clear sky conditions and for different levels of window shadings.

  15. The New York Times headquarters daylighting mockup: Monitoredperformance of the daylighting control system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eleanor S.; Selkowitz, Stephen E.

    2006-02-24

    A nine-month monitored field study of the performance of automated roller shades and daylighting controls was conducted in a 401 m{sup 2} unoccupied, furnished daylighting mockup. The mockup mimicked the southwest corner of a new 110 km{sub 2} commercial building in New York, New York, where The New York Times will be the major tenant. This paper focuses on evaluating the performance of two daylighting control systems installed in separate areas of an open plan office with 1.2-m high workstation partitions: (1) Area A had 0-10 V dimmable ballasts with an open-loop proportional control system and an automated shade controlled to reduce window glare and increase daylight, and (2) Area B had digital addressable lighting interface (DALI) ballasts with a closed-loop integral reset control system and an automated shade controlled to block direct sun. Daylighting control system performance and lighting energy use were monitored. The daylighting control systems demonstrated very reliable performance after they were commissioned properly. Work plane illuminance levels were maintained above 90% of the maximum fluorescent illuminance level for 99.9{+-}0.5% and 97.9{+-}6.1% of the day on average over the monitored period, respectively, in Areas A and B. Daily lighting energy use savings were significant in both Areas over the equinox-to-equinox period compared to a non-daylit reference case. At 3.35 m from the window, 30% average savings were achieved with a sidelit west-facing condition in Area A while 50-60% were achieved with a bilateral daylit south-facing condition in Area B. At 4.57-9.14 m from the window, 5-10% and 25-40% savings were achieved in Areas A and B, respectively. Average savings for the 7-m deep dimming zone were 20-23% and 52-59% for Areas A and B, respectively, depending on the lighting schedule. The large savings and good reliability can be attributed to the automatic management of the interior shades. The DALI-based system exhibited faulty behavior that

  16. Does Daylight Savings Time encourage physical activity?

    Science.gov (United States)

    Zick, Cathleen D

    2014-07-01

    Extending Daylight Savings Time (DST) has been identified as a policy intervention that may encourage physical activity. However, there has been little research on the question of if DST encourages adults to be more physically active. Data from residents of Arizona, Colorado, New Mexico, and Utah ages 18-64 who participated in the 2003-2009 American Time Use Survey are used to assess whether DST is associated with increased time spent in moderate-to-vigorous physical activity (MVPA). The analysis capitalizes on the natural experiment created because Arizona does not observe DST. Both bivariate and multivariate analyses indicate that shifting 1 hour of daylight from morning to evening does not impact MVPA of Americans living in the southwest. While DST may affect the choices people make about the timing and location of their sports/recreational activities, the potential for DST to serve as a broad-based intervention that encourages greater sports/recreation participation is not supported by this analysis. Whether this null effect would persist in other climate situations is an open question.

  17. Fuzzy-Neural Automatic Daylight Control System

    Directory of Open Access Journals (Sweden)

    Grif H. Şt.

    2011-12-01

    Full Text Available The paper presents the design and the tuning of a CMAC controller (Cerebellar Model Articulation Controller implemented in an automatic daylight control application. After the tuning process of the controller, the authors studied the behavior of the automatic lighting control system (ALCS in the presence of luminance disturbances. The luminance disturbances were produced by the authors in night conditions and day conditions as well. During the night conditions, the luminance disturbances were produced by turning on and off a halogen desk lamp. During the day conditions the luminance disturbances were produced in two ways: by daylight contributions changes achieved by covering and uncovering a part of the office window and by turning on and off a halogen desk lamp. During the day conditions the luminance disturbances, produced by turning on and off the halogen lamp, have a smaller amplitude than those produced during the night conditions. The luminance disturbance during the night conditions was a helpful tool to select the proper values of the learning rate for CMAC controller. The luminance disturbances during the day conditions were a helpful tool to demonstrate the right setting of the CMAC controller.

  18. Integrated performance appraisal of Daylight-Europe case study buildings

    NARCIS (Netherlands)

    Hensen, J.L.M.; Clarke, J.A.; Hand, J.W.; Johnson, K.; Wittchen, K.; Madsen, C.; Compagnon, R.

    1996-01-01

    This paper describes the approach taken within the EC’s Daylight-Europe project to apply combined thermal/daylight simulations to existing building designs which are representative of European types and climate contexts. The outputs from the performance appraisals are then incorporated within design

  19. Experiences collected with a daylight system

    International Nuclear Information System (INIS)

    Krueger, P.

    1981-01-01

    The Kodak Daylight System is space-saving. It consists of the Kodak-X-Omat cassette, the identification camera and the loading and reloading device (cassette multiloader). All three units of this system are notable for extremely safe operation. Handling is simple and easily appreciated. All brands of film can be used. The data window in the cassette is too large; in some cases, important sections of the image can be covered up by the window. Automatic loading and reloading considerably reduces solling of the cassette, which is otherwise common, and also reduces abrasion of the intensifying screen. Introduction of this system has had a beneficial effect on overall working and has been welcomed by all concerned as a contribution towards facilitating routine work. (orig.) [de

  20. Analysis and prediction of daylighting and energy performance in atrium spaces using daylight-linked lighting controls

    International Nuclear Information System (INIS)

    Chow, Stanley K.H.; Li, Danny H.W.; Lee, Eric W.M.; Lam, Joseph C.

    2013-01-01

    Highlights: ► Daylight-linked lighting control and energy performance for atrium is studied. ► Field measurement of automatic dimming control shows 93% energy saving. ► Field measurement of manual on–off control shows 95% energy saving. ► Atrium illuminance is correlated with daylight factor for energy saving prediction. - Abstract: In subtropical Hong Kong, a certain amount of electricity is used to create visually comfortable interior spaces through electric lighting, which is the second major electricity-consuming item in commercial buildings, accounting for 20–30% of total electricity use. The burning of fossil fuels for electricity generation has many adverse effects on the environment. Daylighting is an important and useful strategy for enhancing visual comfort and reducing the need for the electricity consumed by light fittings. The rational use of daylight through tools such as photoelectric lighting controls can effectively reduce buildings’ electricity consumption and the related pollutants and greenhouse gas emissions. Daylighting design techniques are often best demonstrated via field measurements that provide reliable operational and energy performance data for establishing design guidelines. An atrium provides an environmentally controlled indoor public space that introduces daylight into the hearts of large buildings. In circulation areas such as corridors, people expect the way ahead to be sufficiently lit and daylight-linked lighting controls can deliver excellent energy savings. This paper presents the daylighting and energy performance of an atrium space using daylight-linked lighting controls. The cost, energy and environmental issues related to various daylight illuminances are estimated and design implications are discussed

  1. Daylight and energy implications for CIE standard skies

    International Nuclear Information System (INIS)

    Li, Danny H.W.

    2007-01-01

    Recently, the International Commission on Illumination (CIE) has adopted a range of 15 standard skies, which include the existing CIE overcast, very clear and cloudless polluted skies, covering the whole probable spectrum of usual skies found in the world. The traditional daylight factor (DF) approach with the calculations being based on an isotropic overcast sky, however, cannot cater to the dynamic variations in daylight luminance and illuminance as the sun's position changes under non-overcast skies. Currently, we propose a numerical procedure that considers the changes in the luminance of sky elements to predict the interior daylight illuminance under the 15 CIE standard skies. This paper evaluates the method by using a typical room with a large vertical glazing window facing north. The available daylight for the room at mean hourly sun positions in each month in terms of DF and illuminance levels were determined and compared with those based on a computer program, namely, RADIANCE. A modification to the ground reflected component was made when a well defined shadow was cast in front of the window facade. It is shown that the results estimated by the proposed approach are in reasonably good agreement with those produced from RADIANCE. The interior daylight and lighting energy consumption were also determined using the proposed and the traditional DF approaches. The findings reveal that daylighting designs using existing CIE overcast sky only would considerably underestimate the indoor daylight availability and electric lighting energy savings, especially under high design indoor illuminance settings

  2. Effects of daylight savings time changes on stock market volatility.

    Science.gov (United States)

    Berument, M Hakan; Dogan, Nukhet; Onar, Bahar

    2010-04-01

    The presence of daylight savings time effects on stock returns and on stock volatility was investigated using an EGARCH specification to model the conditional variance. The evidence gathered from the major United States stock markets for the period between 1967 and 2007 did not support the existence of the daylight savings time effect on stock returns or on volatility. Returns on the first business day following daylight savings time changes were not lower nor was the volatility higher, as would be expected if there were an effect.

  3. effect of daylight hours on performance of growing grasscutters

    African Journals Online (AJOL)

    user

    DNA.Many animals use the daily variation in the duration and quantity of melatonin ... such as reproduction, behavior, coat growth and ... behavioral processes in the biological system. The ... spends the daylight hours sleeping or resting. The.

  4. Teaching Science: Beats the Daylight Out of Me.

    Science.gov (United States)

    Leyden, Michael B.

    1995-01-01

    Presents activities for observing, measuring, collecting, and graphing data about times of sunrise and sunset to teach an understanding about arrival of Daylight Savings Time in April. Also discusses seasonal affective disorder (SAD). (TM)

  5. Daylight savings time and myocardial infarction.

    Science.gov (United States)

    Sandhu, Amneet; Seth, Milan; Gurm, Hitinder S

    2014-01-01

    Prior research has shown a transient increase in the incidence of acute myocardial infarction (AMI) after daylight savings time (DST) in the spring as well as a decrease in AMI after returning to standard time in the fall. These findings have not been verified in a broader population and if extant, may have significant public health and policy implications. We assessed changes in admissions for AMI undergoing percutaneous coronary intervention (PCI) in the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2) database for the weeks following the four spring and three fall DST changes between March 2010 and September 2013. A negative binomial regression model was used to adjust for trend and seasonal variation. There was no difference in the total weekly number of PCIs performed for AMI for either the fall or spring time changes in the time period analysed. After adjustment for trend and seasonal effects, the Monday following spring time changes was associated with a 24% increase in daily AMI counts (p=0.011), and the Tuesday following fall changes was conversely associated with a 21% reduction (p=0.044). No other weekdays in the weeks following DST changes demonstrated significant associations. In the week following the seasonal time change, DST impacts the timing of presentations for AMI but does not influence the overall incidence of this disease.

  6. Investigation of Educational Buildings in Terms of Daylighting Performance

    Directory of Open Access Journals (Sweden)

    İlknur ERLALELİTEPE

    2011-01-01

    Full Text Available Educational buildings have the priority among other building types in daylight performance studies. There are several reasons for this. Classrooms which are used during the whole day should have sufficient and homogeneously distributed daylight. In insufficient daylight conditions, the use of electrical lighting increases energy consumption. Users’ visual comfort should also be assured, and design incorporating natural light requires the analysis of sun protection devices in order to avoid glare and excessive heat. Also, atriums and skylights can be included in the building design with the aim of distributing light equally and in a relatively balanced manner throughout the building. However, lighting schemes are often proposed by architects and professionals who tend to make use of different design tools, and it would be pertinent to investigate whether these tools perform as desired. This study analyses daylight design principles and design elements in educational buildings. It outlines the method which has been used to analyse the daylight performance of buildings. A university building was selected for the field study. Measurements were taken in sample spaces to determine daylight performance. Utilising comparison between standard values and measured values, findings are presented in the form of tables, drawings and figures.

  7. Daylighting Design in Classroom Based on Yearly-Graphic Analysis

    Directory of Open Access Journals (Sweden)

    Yang Guan

    2016-07-01

    Full Text Available In China, existing buildings comprise more than 40 billion square meters, most being of high energy consumption. A substantial reduction in electrical energy costs could be obtained through greater use of daylight. Daylight varies widely due to the movement of sun, changing seasons and diverse weather conditions. Custom static daylight assessments, simulations represent only one time of the year or one time of the day, are inadequate to evaluate the dynamics of daylight variability. Using the intuitive graphic tool Temporal Map to display the annual daylight data, this study compared different passive architectural design strategies under the climate conditions of five representative Chinese cities and selected the most suitable design scheme for each city. In this study, the dynamic yearly-graphic tool was utilized for architectural design in China, and we integrated the optimal design with the Chinese academic calendar to achieve improvements within the occupancy time. This modified map connects design work with human activity that makes daylight evaluation more accurate and efficient. The results of this study will provide preliminary recommendations for energy-saving design in China, and reference to other similar studies.

  8. Light and architecture. Daylight - artificial light - energy; Licht und Architektur. Tageslicht - Kunstlicht - Energie

    Energy Technology Data Exchange (ETDEWEB)

    Wambsganss, M. (ed.) [ip5 ingenieurpartnerschaft, Karlsruhe (Germany)]|[Fachhochschule Rosenheim (Germany)

    2007-07-01

    The symposium intends to provide scientific and technical fundamentals for room lighting with daylight. Daylight deflection systems and artificial light control systems were analyzed for this purpose, and a catalogue of criteria was established. Planners were given tools for projecting daylight control systems. Builder-owners received the fundamentals for economic assessment of combined daylight and artificial light illumination systems, while industrial producers obtained information for further development to maturity and for marketing of daylight-dependent artificial light control systems. (GL)

  9. Light + architecture. Daylight - artificial light - energy; Licht + Architektur. Tageslicht - Kunstlicht - Energie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    The symposium intends to provide scientific and technical fundamentals for room lighting with daylight. Daylight deflection systems and artificial light control systems were analyzed for this purpose, and a catalogue of criteria was established. Planners were given tools for projecting daylight control systems. Builder-owners received the fundamentals for economic assessment of combined daylight and artificial light illumination systems, while industrial producers obtained information for further development to maturity and for marketing of daylight-dependent artificial light control systems. (GL)

  10. Lighting control and dimensioning in integrated daylight systems

    Energy Technology Data Exchange (ETDEWEB)

    Halonen, L.; Eloholma, M.; Lehtovaara, J.

    1996-12-31

    The objective of this research was to find out the subjective and individual requirements for lighting control in connection with daylight utilization in indoor lighting. There is a great potential to use daylight in indoor lighting. This sets demands for the integrated daylight control systems, so that the indoor lighting can be optimized and demands of the users can be fulfilled. Control strategies should also take into account individual light needs, luminance balance and visual comfort. New lighting control systems and strategies such as vertical/horizontal illuminance ratio were studied. The incoming daylight may radically change the luminance distribution of the visual field and the effects of daylight on luminances of vertical surfaces may become especially noticeable. When daylight is utilized in indoor lighting, special care has to be taken to maintain the quality of the lighting of the visual environment. The windows become a potential source of discomfort glare in offices in uncontrolled daylight conditions. With the present methods it is not possible to evaluate discomfort glare caused by high surface luminances or windows. The results of this research do not support the opinion that low vision people in offices need more light than the normally sighted or that the illumination levels should be raised for low vision people. The rise of lighting levels from the present practice (task illuminance level 500 lux) in office work does not improve the visual performance of low vision people. In planning the visual environment for the low vision people care has to be taken on the direction of light. (7 refs.)

  11. Daylight strategies for architectural studio facilities: the literature review

    Science.gov (United States)

    Othman, Muhammad Anas Bin; Azfahani Ahmad, Nur; Ajis, Azizah Md

    2017-05-01

    The implementation of daylighting strategies in buildings is a common aspect in architecture. However, due to the availability of inexpensive electricity, natural lighting strategies became insignificant, and been overlooked by designers. With the current concern over rapid increment on electricity cost, many designers now try to revitalized daylighting strategies in buildings. This includes educational buildings. In Malaysian cases, it is a norm that universities; especially during lecture and studio sessions, used artificial lighting throughout the day. Definitely, this is not parallel with the “green” aim made by the Government in the Malaysian Plan. Therefore, this paper aims to explore the impact of daylight strategies for educational studios in universities, by maximising the penetration of natural daylight into the space towards creating a more green-conducive studio. The paper review literature about the types, criteria and benefits of daylight strategies. This paper also presented a pilot study that has been performed in one university in Perak, Malaysia, by selecting architectural studios as the main subject.

  12. Autonomous physics-based color learning under daylight

    Science.gov (United States)

    Berube Lauziere, Yves; Gingras, Denis J.; Ferrie, Frank P.

    1999-09-01

    An autonomous approach for learning the colors of specific objects assumed to have known body spectral reflectances is developed for daylight illumination conditions. The main issue is to be able to find these objects autonomously in a set of training images captured under a wide variety of daylight illumination conditions, and to extract their colors to determine color space regions that are representative of the objects' colors and their variations. The work begins by modeling color formation under daylight using the color formation equations and the semi-empirical model of Judd, MacAdam and Wyszecki (CIE daylight model) for representing the typical spectral distributions of daylight. This results in color space regions that serve as prior information in the initial phase of learning which consists in detecting small reliable clusters of pixels having the appropriate colors. These clusters are then expanded by a region growing technique using broader color space regions than those predicted by the model. This is to detect objects in a way that is able to account for color variations which the model cannot due to its limitations. Validation on the detected objects is performed to filter out those that are not of interest and to eliminate unreliable pixel color values extracted from the remaining ones. Detection results using the color space regions determined from color values obtained by this procedure are discussed.

  13. New tools for the evaluation of daylighting strategies and technologies

    Energy Technology Data Exchange (ETDEWEB)

    Papamichael, K.; Hitchcock, R.; Ehrlich, C.; Carroll, B.

    1998-03-01

    The use of daylight for the illumination of building interiors has the potential to enhance the quality of the environment while providing opportunities to save energy by replacing or supplementing electric lighting. Moreover, it has the potential to reduce heating and cooling loads, which offer additional energy saving opportunities as well as reductions in HVAC equipment sizing and cost. All of these benefits, however, assume proper use of daylighting strategies and technologies, whose performance depends on the context of their application. On the other hand, improper use can have significant negative effects on both comfort and energy requirements, such as increased glare and cooling loads. To ensure proper use, designers need design tools that model the dynamic nature of daylight and accurately predict performance with respect to a multitude of performance criteria, extending beyond comfort and energy to include aesthetics, cost, security, safety, etc.

  14. Daylight levels during the solar eclipse of 11 August 1999

    Science.gov (United States)

    Darula, S.; Kambezidis, H. D.; Kittler, R.

    Solar eclipses are unique phenomena not only for astronomical and space observations but also for terrestrial; they create unique conditions of sunbeam blockage which cause not only the reduction of direct sunlight but also the dimming of skylight from the whole sky vault. Very favorable conditions were met during the recent August 1999 solar eclipse in Athens, Greece and Bratislava, Slovakia. General class daylight stations operate within the International Daylight Measurements Program in the two cities. One-minute data of global/diffuse illuminance and zenith luminance from those stations have been used to provide information about their levels and the daylight reduction rate during the eclipse. An approximate formula for the estimation of sunlight and skylight illuminance levels as well as zenith luminance using relative luminance sky patterns is also presented in this work. To achieve this, recently developed sky standards together with their parameterizations are utilized.

  15. Impact of three window configurations on daylight conditions

    DEFF Research Database (Denmark)

    Dubois, Marie-Claude; Sørensen, Karl Grau; Traberg-Borup, Steen

    The report describes the results of a pilot study on daylight conditions in simple rooms of residential buildings. As a tool for the analyses the Radiance Lighting Simulating System was used to simulate one room with three different window configurations, a vertical window, a dormer window......, and a roof window. The simulations were performed for overcast sky conditions and under one sunny sky, for two different times of the day. The study shows that the window configuration affects the daylight conditions (distribution and intensity) significantly. The roof window results in a higher (average......) daylight factor on a horizontal plane, i.e. more than twice as high compared with the vertical window, and more than triple as high compared with the dormer window....

  16. Cutaneous leishmaniasis responds to daylight-activated photodynamic therapy

    DEFF Research Database (Denmark)

    Enk, C D; Nasereddin, A; Alper, R

    2015-01-01

    BACKGROUND: Cutaneous leishmaniasis (CL) is endemic in Israel, with hundreds of new cases reported in recent years. Photodynamic therapy (PDT) is highly effective for treatment of CL, but requires equipment available only at specialized centres. Daylight-activated PDT (DA-PDT) abolishes the need...... application of a thick layer of 16% methyl aminolaevulinate and 30-min occlusion, the lesions were exposed to daylight for 2·5 h. Treatment sessions were repeated at weekly intervals until clinical and microbiological cure. Control lesions were either treated with cryotherapy or left untreated. RESULTS...

  17. Design and evaluation of daylighting applications of holographic glazings

    Energy Technology Data Exchange (ETDEWEB)

    Papamichael, K.; Ehrlich, C.; Ward, G.

    1996-12-01

    According to the contractual agreement, BTP would develop a computer model of the POC holographic structures and then simulate the performance of alternative designs using the RADIANCE lighting and rendering computer program [Ward 1990]. The RADIANCE model would then be used to evaluate the daylight performance of alternative designs of holographic glazings in a prototypical office space. The simulation process would be validated against actual photometric measurements of holographic glazing samples developed by POC. The results would be used to evaluate the potential for increased electric lighting savings through increased daylight illuminance levels at distances more than 15 ft--20 ft (4.6 m--6.1 m ) from the window wall.

  18. The study on the computer analysis of solar daylighting system in the schoolroom

    Energy Technology Data Exchange (ETDEWEB)

    Oh, W. J.; Makhmudov, I.; Lee, Y. J.; Chun, W. G. [Jeju National University, Jeju (Korea, Republic of)

    2010-10-15

    Daylighting is the efficient use of natural light in order to minimize the need for artificial light in buildings. A well thought out building designed with daylighting can have a number of significant benefits for building owners and occupants. Increasing levels of daylight within rooms can reduce electrical lighting loads by up to 70% in some cases. In this study, the daylighting system using mini dish and optical fiber was analyzed for application to the schoolroom by the simulation of ECOTECT and RADIANCE

  19. Daylight savings time transitions and the incidence rate of unipolar depressive episodes

    DEFF Research Database (Denmark)

    Hansen, Bertel T; Sønderskov, Kim M; Hageman, Ida

    2017-01-01

    Background: Daylight savings time transitions affect approximately 1.6 billion people worldwide. Prior studies have documented associations between daylight savings time transitions and adverse health outcomes, but it remains unknown whether they also cause an increase in the incidence rate...... of depressive episodes. This seems likely because daylight savings time transitions affect circadian rhythms, which are implicated in the etiology of depressive disorder. Therefore, we investigated the effects of daylight savings time transitions on the incidence rate of unipolar depressive episodes. Methods...

  20. Predicting daylight illuminance on inclined surfaces using sky luminance data

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.H.W.; Lau, C.C.S.; Lam, J.C. [City University of Hong Kong, Kowloon (China). Dept. of Building and Construction

    2005-07-01

    Daylight illuminance, particularly on vertical surfaces, plays a major role in determining and evaluating the daylighting performance of a building. In many parts of the world, however, the basic daylight illuminance data for various vertical planes are not always readily available. The usual method to obtain diffuse illuminance on tilted planes would be based on inclined surface models using data from the horizontal measurements. Alternatively, the diffuse illuminance on a sloping plane can be computed by integrating the luminance distribution of the sky 'seen' by the plane. This paper presents an approach to estimate the vertical outdoor illuminance from sky luminance data and solar geometry. Sky luminance data recorded from January 1999 to December 2001 in Hong Kong and generated by two well-known sky luminance models (Kittler and Perez) were used to compute the outdoor illuminance for the four principal vertical planes (N, E, S and W). The performance of this approach was evaluated against data measured in the same period. Statistical analysis indicated that using sky luminance distributions to predict outdoor illuminance can give reasonably good agreement with measured data for all vertical surfaces. The findings provide an accurate alternative to determine the amount of daylight on vertical as well as other inclined surfaces when sky luminance data are available. (author)

  1. Daylighting System Based on Novel Design of Linear Fresnel lens

    Directory of Open Access Journals (Sweden)

    Thanh Tuan Pham

    2017-10-01

    Full Text Available In this paper, we present a design and optical simulation of a daylighting system using a novel design of linear Fresnel lens, which is constructed based on the conservation of optical path length and edge ray theorem. The linear Fresnel lens can achieve a high uniformity by using a new idea of design in which each groove of the lens distributes sunlight uniformly over the receiver so that the whole lens also uniformly distributes sunlight over the receiver. In this daylighting system, the novel design of linear Fresnel lens significantly improves the uniformity of collector and distributor. Therefore, it can help to improve the performance of the daylighting system. The structure of the linear Fresnel lenses is designed by using Matlab. Then, the structure of lenses is appreciated by ray tracing in LightToolsTM to find out the optimum lens shape. In addition, the simulation is performed by using LightToolsTM to estimate the efficiency of the daylighting system. The results show that the designed collector can achieve the efficiency of ~80% with the tolerance of ~0.60 and the concentration ratio of 340 times, while the designed distributor can reach a high uniformity of >90%.

  2. Solar Shading System Based on Daylight Directing Glass Lamellas

    DEFF Research Database (Denmark)

    Laustsen, Jacob Birck; Santos, Inês; Svendsen, Svend

    2008-01-01

    The overheating problems in office buildings must be solved with efficient solar shadings in order to reduce the energy demand for cooling and ventilation. At the same time the solar shading should not reduce the daylight level in the building on overcast days because it would result in a lower...

  3. Daylight Saving Time Transitions and Road Traffic Accidents

    Directory of Open Access Journals (Sweden)

    Tuuli Lahti

    2010-01-01

    Full Text Available Circadian rhythm disruptions may have harmful impacts on health. Circadian rhythm disruptions caused by jet lag compromise the quality and amount of sleep and may lead to a variety of symptoms such as fatigue, headache, and loss of attention and alertness. Even a minor change in time schedule may cause considerable stress for the body. Transitions into and out of daylight saving time alter the social and environmental timing twice a year. According to earlier studies, this change in time-schedule leads to sleep disruption and fragmentation of the circadian rhythm. Since sleep deprivation decreases motivation, attention, and alertness, transitions into and out of daylight saving time may increase the amount of accidents during the following days after the transition. We studied the amount of road traffic accidents one week before and one week after transitions into and out of daylight saving time during years from 1981 to 2006. Our results demonstrated that transitions into and out of daylight saving time did not increase the number of traffic road accidents.

  4. Effect of window glazing on colour quality of transmitted daylight

    NARCIS (Netherlands)

    Dangol, R.; Kruisselbrink, T.W.; Rosemann, A.L.P.

    2017-01-01

    In this study, the colour quality of the daylight transmitted through different window glazing types is evaluated. The analysis considered four different types of window glazing: laminated, monolithic, coated and applied film glazing ranging in luminous transmittance from around 0.97 to <0.1. The

  5. The effect of different weather data sets and their resolution on climate-based daylight modelling

    DEFF Research Database (Denmark)

    Iversen, A; Svendsen, Svend; Nielsen, Toke Rammer

    2013-01-01

    Climate-based daylight modelling is based on the available weather data, which means that the weather data used as input to the daylight simulations are of great importance. In this paper, the effect on the outcome of the daylight simulations of using one weather data file rather than another...

  6. NOUR. Daylighting and thermal effects of windows in desert houses

    Energy Technology Data Exchange (ETDEWEB)

    Ouahrani, Djamel

    1999-07-01

    This study is on a combined effect of window, the daylighting and the thermal effects, in desert houses. It is comprised of two complementary studies. In the introduction a historical review on the development of using daylight has been carried out in order to place the case study in a historical perspective. The first study is comprehensive and contains two main parts. In the first part a study was carried out on the people and history of the town of Ghardaia in Southern Algeria. This was done in order to understand the architectural form of that region. The second part is experimental and consists of two field studies carried out in Ghardaia. Their aim was to investigate the influence of daylight and temperature on the use of residential houses. This investigation included both traditional and 'modern' houses, the modern having relatively large windows similar to those of the northern part of Algeria, the traditional ones having small or no windows. The second study is also experimental consisting of computer parametric studies on window design from two standpoints, namely daylighting level and thermal effects of windows in desert houses. A typical traditional house is described as it was observed. Then the recorded light values are presented and commented upon. In the second part, three types of modern houses observed in the field studies are presented and compared to the traditional archetype. The comparison especially dwells on the relative effectiveness of the two systems of daylighting. In the third part, focusing on various issues of lighting, the results of interviews with the inhabitants are presented. The historical studies indicate that the process of housing development, in several respects, has reached a certain quality (social, technology, and adaptation to climate) appropriate to the local original context, but that development has slowed down. The results of the lighting study indicate that the use of more windows in modern houses

  7. NOUR. Daylighting and thermal effects of windows in desert houses

    Energy Technology Data Exchange (ETDEWEB)

    Ouahrani, Djamel

    1999-07-01

    This study is on a combined effect of window, the daylighting and the thermal effects, in desert houses. It is comprised of two complementary studies. In the introduction a historical review on the development of using daylight has been carried out in order to place the case study in a historical perspective. The first study is comprehensive and contains two main parts. In the first part a study was carried out on the people and history of the town of Ghardaia in Southern Algeria. This was done in order to understand the architectural form of that region. The second part is experimental and consists of two field studies carried out in Ghardaia. Their aim was to investigate the influence of daylight and temperature on the use of residential houses. This investigation included both traditional and 'modern' houses, the modern having relatively large windows similar to those of the northern part of Algeria, the traditional ones having small or no windows. The second study is also experimental consisting of computer parametric studies on window design from two standpoints, namely daylighting level and thermal effects of windows in desert houses. A typical traditional house is described as it was observed. Then the recorded light values are presented and commented upon. In the second part, three types of modern houses observed in the field studies are presented and compared to the traditional archetype. The comparison especially dwells on the relative effectiveness of the two systems of daylighting. In the third part, focusing on various issues of lighting, the results of interviews with the inhabitants are presented. The historical studies indicate that the process of housing development, in several respects, has reached a certain quality (social, technology, and adaptation to climate) appropriate to the local original context, but that development has slowed down. The results of the lighting study indicate that the use of more windows in modern houses constitutes a

  8. Natural Light is the Right Light - Daylighting Design and Technology between Architecture, Art and Sustainability

    DEFF Research Database (Denmark)

    Osterhaus, Werner

    2009-01-01

    Within contemporary architecture, the art of daylighting design ? despite its many recognized advantages in comparison with electric lighting ? still encounters skepticism, primarily because it is usually developed and articulated more intuitively, rather than technically. Innovative daylighting ...... daylighting design with an open mind and an appreciation for basic human needs....... applications have added sparkle and interest to buildings. The sun?s rays have been captured to create magnificent plays of forms in light. People perceive daylight as an essential element of life. But architects, lighting designers, and clients alike, often underestimate the importance of daylight for human...

  9. The costs and benefits of using daylight guidance to light office buildings

    Energy Technology Data Exchange (ETDEWEB)

    Mayhoub, M.S.; Carter, D.J. [School of Architecture, University of Liverpool (United Kingdom)

    2011-03-15

    Daylight guidance systems are linear devices that channel daylight into the core of a building. This paper analyses costs and benefits of using the two main classes of daylight guidance to light offices as an alternative to conventional electric lighting. The work demonstrates that daylight guidance is generally not economical using conventionally accepted measures of both cost and benefit. It is shown that if intangible benefits associated with the delivery of daylight to offices are included in an analysis, a more favourable balance of cost and benefit is obtained. The implications of this for practical use of the systems are discussed. (author)

  10. DAYLIGHTING PERFORMANCE OF HORIZONTAL LIGHT PIPE BRANCHING ON OPEN PLAN OFFICE SPACE

    Directory of Open Access Journals (Sweden)

    Feny ELSIANA

    2015-12-01

    Full Text Available For daylighting purpose, office buildings should have a shallow plan and increase the ratio of surface to building’s volume. However, intensive use of air-conditioning drives office building’s plan to be deep with a minimum surface to volume ratio. This leads to the presence of areas that have insufficient daylight level at the work plane. Considering limitations of some daylighting methods in distributing daylight to these areas, Horizontal Light Pipe (HLP was selected. The aim of this research was to evaluate and explain the effect of HLP branching on daylight quantity and distribution inside open plan office space. Experimental with simulation as a tool was used as the research method. HLP branching’s uniformity ratio, illuminance and Daylight Factor were compared with unbranching HLP, simultaneously with daylighting standards. Results showed that office space with HLP-L branching had higher daylight level than HLP-T branching, 296 lux and 295 lux, HLP-L and HLP-T, respectively. However, HLP-T branching distributed daylight more evenly than HLP-L branching, with uniformity ratio as 1.49:1 and 1.50:1, HLP-T and HLP-L, respectively. Both of them met the illuminance target value and uniformity at work plane. Light’s deflection and improvement amount of opening distribution decreased average illuminance and Daylight Factor up to 3.59%. Those also decreased uniformity of daylight inside the space.

  11. Phases of daylight and the stability of color perception in the near peripheral human retina.

    Science.gov (United States)

    Panorgias, Athanasios; Kulikowski, Janus J; Parry, Neil R A; McKeefry, Declan J; Murray, Ian J

    2012-03-01

    Typical daylight extends from blue (morning sky) to orangey red (evening sky) and is represented mathematically as the Daylight Locus in color space. In this study, we investigate the impact of this daylight variation on human color vision. Thirty-eight color normal human observers performed an asymmetric color match in the near peripheral visual field. Unique hues were identified using a naming paradigm. The observers' performance for matching was almost perfectly coincident with the Daylight Locus but declined markedly in other regions. Interobserver variability reached a conspicuous minimum adjacent to the Daylight Locus and was maximal in the red and yellowish-green regions. In the naming task, unique blue and yellow were virtually coincident with the Daylight Locus. The results suggest that the mechanisms of color perception mediated by the phylogenetically older (blue-yellow) color pathway have been strongly influenced by the different phases of daylight.

  12. From dark to bright: novel daylighting applications in solid state lighting

    Science.gov (United States)

    Adler, Helmar G.

    2011-10-01

    The term "daylighting" is used in various ways, on one hand in a more architectural sense, i.e. using existing daylight to illuminate spaces, and on the other, more recently, for using light sources to replicate daylight. The emergence of solid state lighting (SSL) opens up a large number of new avenues for daylighting. SSL allows innovative controllability of intensity and color for artificial light sources that can be advantageously applied to daylighting. With the assistance of these new technologies the combination of natural and artificial lighting could lead to improvements in energy savings and comfort of living beings. Thus it is imperative to revisit or even improve daylighting research so that building networks of the future with their sensor, energy (e.g. HVAC) and lighting requirements can benefit from the emerging capabilities. This paper will briefly review existing daylighting concepts and technology and discuss new ideas. An example of a tunable multi-color SSL system will be shown.

  13. The daylighting dashboard - A simulation-based design analysis for daylit spaces

    Energy Technology Data Exchange (ETDEWEB)

    Reinhart, Christoph F. [Harvard University, Graduate School of Design, 48 Quincy Street, Cambridge, MA 02138 (United States); Wienold, Jan [Fraunhofer Institute for Solar Energy Systems, Heidenhofstrasse 2, 79110 Freiburg (Germany)

    2011-02-15

    This paper presents a vision of how state-of-the-art computer-based analysis techniques can be effectively used during the design of daylit spaces. Following a review of recent advances in dynamic daylight computation capabilities, climate-based daylighting metrics, occupant behavior and glare analysis, a fully integrated design analysis method is introduced that simultaneously considers annual daylight availability, visual comfort and energy use: Annual daylight glare probability profiles are combined with an occupant behavior model in order to determine annual shading profiles and visual comfort conditions throughout a space. The shading profiles are then used to calculate daylight autonomy plots, energy loads, operational energy costs and green house gas emissions. The paper then shows how simulation results for a sidelit space can be visually presented to simulation non-experts using the concept of a daylighting dashboard. The paper ends with a discussion of how the daylighting dashboard could be practically implemented using technologies that are available today. (author)

  14. Lives under the Sun; The sensory qualities of daylight in designing the everyday

    DEFF Research Database (Denmark)

    Hauge, Bettina

    2015-01-01

    People’s sensations of daylight and their practical, daily engagements with the sun and the daylight are described in this article. Based on a qualitative research project in Denmark the article shows how some Danes experience the world through the sun and its daylight and illustrates its...... significance to their bodies and lives as they describe it. By taking a biomimetic approach a metaphor is presented that, like plants, some people crave daylight in order to feel well. By showing people’s engagement with the sun and its daylight the phenomenon of natural light becomes imbued with sociality...... and it is described how people design their everyday in accordance with the sun. The sensation of daylight normally taken for granted and acknowledged as a physiological element in our being-in-the-world is foregrounded and shown as a sense in people that may have a physiological origin when daylight hits the eye...

  15. Investigation of Architectural Strategies in Relation to Daylight and Integrated Design

    DEFF Research Database (Denmark)

    Jørgensen, Michael; Iversen, Anne; Bjerregaard Jensen, Lotte

    2012-01-01

    his paper investigates the use of daylight in three architecturally successful buildings. The aim is to discuss the challenges and opportunities of architectural daylight strategies in relation to integrated design. All these buildings were designed with the focus on a strategy of using daylight...... to create well-lit, exciting spaces and spatial sequences. The original ideas, thoughts, and decisions behind the designs and daylight strategy are compared with answers in questionnaires from test subjects who have experienced the space and lighting conditions created. The results indicate...... that the architectural daylight strategies formulated by the architects and engineers at the beginning of the design process are actually experienced by the “users” in the existing buildings. The architectural daylight strategy was different in each of the three libraries, and analysis of the results shows that daylight...

  16. Does Daylight Saving Save Energy? A Meta-Analysis

    OpenAIRE

    Havránek, Tomáš; Herman, Dominik; Irsova, Zuzana

    2016-01-01

    The original rationale for adopting daylight saving time (DST) was energy savings. Modern research studies, however, question the magnitude and even direction of the effect of DST on energy consumption. Representing the first meta-analysis in this literature, we collect 162 estimates from 44 studies and find that the mean reported estimate indicates modest energy savings: 0.34% during the days when DST applies. The literature is not affected by publication bias, but the results vary systemati...

  17. Byron G. Rogers Federal Building Harvests Daylight and Super Savings

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-01-01

    Case study describes how the Byron G. Rogers Federal Building replaced existing T12 and T8 luminaires with LED dedicated troffers with advanced controls. Together these measures cut lighting energy use by nearly 60% in the 18-story, 791,000-square-foot facility. The new lighting control system provides automated dimming of lights down to 0% output when daylight provides adequate light levels. The project earned GSA an award for exemplary performance from the Interior Lighting Campaign in 2016.

  18. Daylighting in linear atrium buildings at high latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Matusiak, Barbara

    1998-12-31

    This thesis proposes new criteria for visual comfort based on knowledge of visual perception and a method for estimating the modelling ability of light by using inter-reflection calculations. Simplified calculations are presented for the daylight factor in linear building structures, using the projected solid angle principle, for uniform sky and for CIE overcast sky conditions. The calculations are compared with experimental results. Simple diagrams are created based on calculations of the mean daylight factor in rooms adjacent to a narrow street. These diagrams and presented formulas and tables can be used as a simple design tool. Daylighting strategies for linear atrium buildings at high latitudes are developed and examined. These strategies are divided into three groups: (1) the atrium space and facades as light conductor/reflector, (2) the glass roof as a light conductor, and (3) light reflectors on the neighbouring roof. The atrium space and facade strategies are subdivided into passive and active. The strategies connected to the glazed roof includes different configurations of glazing: horizontal, single pitched, double pitched, and the use of laser cut panels and prismatic panels in the glazed roof. The shapes of reflectors on the neighbouring roof are a flat reflector, a parabolic reflector and a parabolic concentrator. Strategies from all three groups are examined on a physical model of scale 1:20 in the artificial sky of mirror box type. Simulations with artificial sun have also been done. The results from model studies are compared with computer simulations. All the active daylighting systems designed for use in the atrium space or on the atrium facades have a huge potential for use in atrium buildings. From the strategies connected with the glazed roof the negatively sloped glass is found to be the best alternative for glazed roofs at high latitudes. Among the roof reflectors, the flat one performs best. 82 refs., 122 figs., 27 tabs.

  19. Optimal tree design for daylighting in residential buildings

    Energy Technology Data Exchange (ETDEWEB)

    Hongbing, Wang [College of Landscape Architecture, Beijing Forestry University, 35, East Qinghua Rd., Beijing (China); Shanghai Botanical Garden, 1111, Longwu Rd., Shanghai (China); Jun, Qin; Yonghong, Hu [Shanghai Botanical Garden, 1111, Longwu Rd., Shanghai (China); Li, Dong [College of Landscape Architecture, Beijing Forestry University, 35, East Qinghua Rd., Beijing (China)

    2010-12-15

    Urban reforestation is advocated as an efficient countermeasure to the intensification of urban heat islands. The greening and beautification of residential quarters is one of the main concerns of residents, while lighting and ventilation are two main energy-consuming building services. Hence, the tree layout in green space between buildings is important, and it is necessary to determine the relationships between trees and buildings. This study takes Shanghai as a case study to optimize tree design between residential buildings and meet good daylighting requirements. Models were made using software such as AutoCAD and SketchUp. The relationships between maximum tree height and building separation were determined. For the same building layout, there were different tree height limits according to crown shape; the order of decreasing height limits was cylindrical, conical, spherical, and inverted conical crowns. Three cases having different green space between building layouts were studied. Their maximum tree heights differed. Overall, our model helps us realize good daylighting of a building environment. The formula allows us to determine which trees to plant between buildings in that we can predict the effects of future tree growth on building daylighting. (author)

  20. Impact of shading on daylight quality. Simulations with radiance

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, M.C.

    2001-07-01

    The impact of six exterior shading devices on daylight quality and on the potential for daylight utilisation in a standard, south-oriented office room was investigated through computer simulations with Radiance. The daylight quality was evaluated by considering four performance indicators: the absolute work plane illuminance, the illuminance uniformity on the work plane, the absolute luminance in the visual field and the luminance ratios between the work plane, VDT screen and surrounding surfaces. The results indicate that the overhang, white awning and horizontal venetian blind generated work plane illuminance levels that are more suitable for offices where traditional tasks are carried out. However, these devices did not prevent high luminance values at the window. On the other hand, the grey specular screen produced unacceptably low work plane illuminance, poor illuminance uniformity and unacceptably low luminance levels which resulted in unsuitable luminance ratios between the VDT screen, work plane and surroundings. The 45 deg venetian blind, white screen and blue awning provided work plane illuminance levels suitable for offices where a combination of paper and computer work is carried out. They also provided acceptable illuminance uniformity on the work plane, suitable luminance ratios between the work plane, VDT screen and surroundings and they significantly reduced the luminance of the window. However, the blue awning had a poorer performance in December than in June and the white screen resulted in high luminance values at the window, which indicates that the best device among the ones studied was the 45 deg venetian blind.

  1. Method for including detailed evaluation of daylight levels in Be06

    DEFF Research Database (Denmark)

    Petersen, Steffen

    2008-01-01

    Good daylight conditions in office buildings have become an important issue due to new European regulatory demands which include energy consumption for electrical lighting in the building energy frame. Good daylight conditions in offices are thus in increased focus as an energy conserving measure....... In order to evaluate whether a certain design is good daylight design or not building designers must perform detailed evaluation of daylight levels, including the daylight performance of dynamic solar shadings, and include these in the energy performance evaluation. However, the mandatory national...... calculation tool in Denmark (Be06) for evaluating the energy performance of buildings is currently using a simple representation of available daylight in a room and simple assumptions regarding the control of shading devices. In a case example, this is leading to an overestimation of the energy consumption...

  2. Daylighting on the working plane in oriented attic rooms under overcast and clear sky

    Directory of Open Access Journals (Sweden)

    Kondáš Kristián

    2014-06-01

    Full Text Available The evaluation of daylight conditions in building interiors is based on the Daylight Factor concept after current Slovak standards. Criteria and requirements determined in these standards consider the worst daylight exterior conditions which are described by CIE overcast sky model. The sky luminance distribution of overcast sky is centrical to the zenith, so independence of window orientation to cardinal points is characteristic in daylighting calculations. The sky luminance distribution modelling is one of the main task of the daylight source research more than 50 years. It is evident that also other types of sky conditions exist in nature. An introduction of a new criterion based on photometric variables, which also consider sunlight influence, is expected. This article represents a study of the influence of the interior orientation on distribution of daylighting in attic spaces under an overcast and clear sky

  3. Could Daylight Glare Be Defined Mathematically?Results of Testing the DGIN Method in Japan

    Science.gov (United States)

    Nazzal, Ali; Oki, Masato

    Discomfort glare from daylight is a common problem without valid prediction methods so far. A new mathematical DGIN (New Daylight Glare Index) method tries to respond the challenge. This paper reports on experiments carried out in daylit office environment in Japan to test applicability of the method. Slight positive correlation was found between the DGIN and the subjective evaluation. Additionally, a high Ladaptation value together with the small ratio of Lwindow to Ladaptation was obviously experienced sufficient to neutralize the effect of glare discomfort. However, subjective assessments are poor glare indicators and not reliable in testing glare prediction methods. DGIN is a good indicator of daylight glare, and when the DGIN value is analyzed together with the measured illuminance ratios, discomfort glare from daylight can be analyzed in a quantitative manner. The DGIN method could serve architects and lighting designers in testing daylighting systems, and also guide the action of daylight responsive lighting controls.

  4. Hybrid daylight/light-emitting diode illumination system for indoor lighting.

    Science.gov (United States)

    Ge, Aiming; Qiu, Peng; Cai, Jinlin; Wang, Wei; Wang, Junwei

    2014-03-20

    A hybrid illumination method using both daylight and light-emitting diodes (LEDs) for indoor lighting is presented in this study. The daylight can be introduced into the indoor space by a panel-integration system. The daylight part and LEDs are combined within a specific luminaire that can provide uniform illumination. The LEDs can be turned on and dimmed through closed-loop control when the daylight illuminance is inadequate. We simulated the illumination and calculated the indoor lighting efficiency of our hybrid daylight and LED lighting system, and compared this with that of LED and fluorescent lighting systems. Simulation results show that the efficiency of the hybrid daylight/LED illumination method is better than that of LED and traditional lighting systems, under the same lighting conditions and lighting time; the method has hybrid lighting average energy savings of T5 66.28%, and that of the LEDs is 41.62%.

  5. Using the whole-building design approach to incorporate daylighting into a retail space: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hayter, S.; Torcellini, P.; Eastment, M.; Judkoff, R.

    2000-06-21

    This paper focuses on implementation of daylighting into the Bighorn Center, a collection of home improvement retail spaces in Silverthorne, Colorado, which were constructed in three phases. Daylighting was an integral part of the design of the Phase 3 building. Energy consultants optimized the daylighting design through detailed modeling using an hourly building energy simulation tool. Energy consultants also used this tool to address the building owner's concerns related to customer comfort and increased product sales.

  6. Daylighting as the Driving Force of the Design Process: from the Results of a Survey to the Implementation into an Advanced Daylighting Project

    Directory of Open Access Journals (Sweden)

    Valerio R.M. Lo Verso

    2014-12-01

    Full Text Available This paper presents a study for the transformation of an industrial area in Turin, Italy. The area hosts two buildings (one of which appointed as listed to be transformed into dwellings. A synergic approach was adopted which combined expertise from architecture, social-economics, psychology and building physics sciences. Building physics sciences lead the research team. A user-centered design was pursued, using a bottom-up approach. A specifically developed questionnaire was submitted on-line to potential users. The survey showed that ‘amount of daylight’, ‘size of rooms’, ‘tranquility of the area’ and ‘presence of a private garden’ were perceived by users to be the most positive aspects of both their present and future, ideal home. These results were then implemented into the project. The exploitation of daylight became the driving force of the transformation project. Especially for the listed building, skylights and light wells were designed to bring daylight into the cores of the buildings, which host common spaces such as libraries or study rooms. The amount of daylight was assessed through the legislative index of the average daylight factor and through a climate-based modeling approach, calculating dynamic metrics such as the spatial daylight autonomy and the Useful Daylight Illuminance. The paper critically compares and discusses these two approaches. Finally, the energy demand for lighting was also calculated to analyze how the increased exploitation of daylight may imply a reduced need for electricity for lighting.

  7. Impact of Furniture Layout on Indoor Daylighting Performance in Existing Residential Buildings in Malaysia

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Mousavi

    2018-06-01

    Full Text Available Currently, home-based computing workspaces have developed substantially all over the world, especially in Malaysia. This growing trend attracts computer workers to run a business from their residential units. Hence, visual comfort needs to be considered in addition to thermal comfort for home workers in their residential working rooms. While such rooms are always occupied with furniture, the layout of the furniture may influence the indoor daylighting distribution. Several various furniture layouts can be arranged in a residential working room. However, to have better generalisation, this study focused on the impacts of mostly-used-furniture-layouts (MUFLs on indoor daylighting performance in residential working rooms. The field measurement was conducted in a typically furnished room under a tropical sky to validate the results of the simulation software under different sky conditions. Then, daylight ratio (DR, as a quantitative daylighting variable, and the illuminance uniformity ratio (IUR, CIE glare index (CGI, and Guth visual comfort probability (GVCP, as qualitative daylighting variables, were analysed through simulation experiments. In conclusion, by changing the furniture layout, daylight uniformity recorded the highest fluctuations in the case room among all variables. While various furniture layouts, in a residential working room in the tropics, may even slightly reduce the extreme indoor daylight quantity, they can worsen the indoor daylight quality compared to an unfurnished space. The paper shows that furniture as an interior design parameter cannot help to improve tropical daylighting performance in a building.

  8. Evaluation of Daylight Intensity for Sustainbility in Residential Buildings in Cantonment Cottages Multan

    Directory of Open Access Journals (Sweden)

    SUMRA YOUSUF

    2017-07-01

    Full Text Available Day lighting is a useful and effective source of energy savings and visual comforts in buildings. Occupants expect good daylight in their living spaces for better living environment. The quality and quantity of natural light entering in to a building depend on both internal and external factors. Daylight strategies basically depend on the accessibility of natural light that is determined by the latitude of the building site and the conditions surrounding the building. Daylight provides lighting energy and energy demand reduction during peak utility hours. Bringing daylight into a building that displaces electric lighting and provides sufficient illumination is the greenest way to light a building presently. This research, aims at analyzing the daylight intensity in residential buildings in Cantonment Cottages Multan which is one of the hottest and progresse city of Pakistan. The intensity of daylight can be expressed in the terms of luminance and daylight factor. In this research, the 5 and 7 marla houses in Cantt Cottages in Multan were selected. The device lux meter was used for measuring intensity with which the brightness appears to the human eye. The readings were taken by placing Lux Meter at the center and near windows in each building component at 2-4 pm. Inorderto evaluate the daylight intensity, the measured luminance in each component of building is compared with the standard illuminance as per recommendation of CIBSE (Chartered Institute of Building Service Engineers. After investigation, it has been found that daylight factor is much higher than the standard values

  9. Practicality and Performance of Daylight Trough in The Tropics: A Case Study

    Directory of Open Access Journals (Sweden)

    Gene-Harn Lim

    2016-01-01

    Full Text Available The field of office daylighting is vital for both energy efficiency practice and occupants’ visual comfort. With the emergence of green building in Malaysia, building designers are exploring avenues for energy efficiency design; one common strategy is daylighting. The majority literature reviews on daylighting are skewed towards temperate or developed countries, where sky luminous condition is different from that of the Tropics. Conventional daylighting system designs redirect daylight from the envelope or atrium openings, such as light shelves. Presumed to be the pioneer daylight trough in the Tropics, this paper presents the simulated and in-situ lighting level measurements prior to occupancy. This case study presents an as-built daylight trough design which is able to daylight the office space as deep as 6 meters sufficiently. It achieves a lighting power density 1.90W/m2 and saves 39.2% of lighting energy over conventional office lighting energy. Discussed further is the practicality of working with such a system, including cost implication, return on investment and contractual challenges in reaching a consensus on the design. The results reinforce that the effectiveness of daylighting design is very dependable on the sun path and obstacles surrounding the office tower. The RADIANCE simulation correlates well to field measurement results. Further investigation into the light trough, its lighting energy savings, users’ interaction, visual comfort, and glare is still ongoing.

  10. Glazing for intelligent daylight utilisation; Verglasungen fuer die intelligente Tageslichtnutzung

    Energy Technology Data Exchange (ETDEWEB)

    Rubbert, F. [VEGLA Vereinigte Glaswerke GmbH, Aachen (Germany)

    1999-10-01

    Daylight, a part of the solar energy incident on the Earth`s surface, is available to us for free and usually in sufficient quantity. Nevertheless, in office and administration buildings artificial lighting is used for an average 60% of total occupancy time. This figure refers not only those times of the year and day when daylight intensity is naturally weak but also includes periods when sunlight is available in excess. To minimise buildings` absorption of solar energy (and so reduce the cooling load) and shield workplaces against direct sunlight, frequent use is made of mechanical shading systems which necessitate the use of artificial lighting, this in turn adding to the cooling load. Several daylight systems have been developed and are now increasingly being used to resolve this paradoxical situation. [Deutsch] Tageslicht, als Bestandteil der Sonnenenergie, steht uns taeglich kostenlos und meistens in ausreichender Menge zur Verfuegung. Dennoch wird in Buero- und Verwaltungsgebaeuden die kuenstliche Beleuchtung im Durchschnitt waehrend etwa 60% der Nutzungszeit eingeschaltet. Dies jedoch nicht nur waehrend der tages- und jahreszeitlich bedingten Phasen mit einer geringen natuerlichen aeusseren Beleuchtungsstaerke, sondern gerade auch zu den Zeiten in denen Sonnenlicht im Uebermass zur Verfuegung steht. Denn zur Minimierung der in die Gebaeude eingebrachten solaren Energie (Reduzierung der Kuehllasten) und zur Erzielung eines Blendschutzes an den betroffenen Arbeitsplaetzen werden sehr haeufig mechanische Verschattungssysteme benutzt, die ein Zuschalten der kuenstlichen Beleuchtung erforderlich machen und somit wieder zu einer Erhoehung der Kuehllasten fuehren. Um dieser Parodoxie aufzuloesen, wurden einige Tageslichtsysteme entwickelt, die im zunehmenden Masse auch praktisch angewandt werden. (orig.)

  11. Analysis of daylight calculated using the EnergyPlus programme

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Greici; Ghisi, Enedir [Universidade Federal de Santa Catarina, Departamento de Engenharia Civil, Laboratorio de Eficiencia Energetica em Edificacoes, Caixa Postal 476, Florianopolis - SC 88040-900 (Brazil)

    2010-09-15

    In order to properly evaluate the thermal energy performance of buildings it is also necessary to analyse the use of daylight, since this influences the thermal load of a building. In this context, the aim of this study was to evaluate the calculation of internal illuminances carried out using the EnergyPlus simulation programme. The analysis was carried out through a comparison of the Useful Daylight Illuminances (UDI) and the daylight factor (DF) estimated using the EnergyPlus programme with the results from another two programmes: Daysim/Radiance and TropLux. Also, the external horizontal illuminance estimated using EnergyPlus was compared with that measured in Florianopolis, Santa Catarina State, Brazil, between 2003 and 2005. The simulations were carried out for three different rooms: one square (5 m x 5 m x 3 m), one shallow rectangular (10 m x 5 m x 3 m) and one deep rectangular (5 m x 10 m x 3 m). From this analysis it was verified that the EnergyPlus programme has a problem related to both the DF and the external illuminance values. A comparison between the DF values calculated using the three programmes shows that there is a problem in EnergyPlus related to solving the internal reflection, such that the greater the importance of the portion of light reflected, the greater the difference found between the programmes. A comparison between the calculated and measured external horizontal illuminances shows differences greater than 100% both for the diffuse and direct illuminances indicating that the EnergyPlus programme overestimates these values. (author)

  12. Application of automated blind for daylighting in tropical region

    International Nuclear Information System (INIS)

    Chaiwiwatworakul, Pipat; Chirarattananon, Surapong; Rakkwamsuk, Pattana

    2009-01-01

    This paper reports an experimental and simulation study on application of automated Venetian blind for daylighting in tropical climate. A horizontal blind system operating automatically under programmed control was constructed and integrated onto the glazed windows to form a window system with an automated blind in a room of a laboratory building. A dimming controller was also integrated to the lighting system of the room. Different operation schemes of the window system were devised and tested in the attempt to maximize energy savings while maintaining the quality of the visual environment in the room. Intensive measurement of illuminance of the interior space was undertaken during the experiments. A methodology for calculation of interior daylight illuminance and associated glare corresponding to the configurations of the experiments was adopted. The method was coded into a computer program. Results of calculation from the program agree well with those from experiments for all the schemes of operation conducted. The program was used to simulate the situation when each scheme of operation was implemented for a whole year. It was found that such window system with automated blind enabled energy savings of 80%, but a more sophisticated scheme also helped maintain the interior visual quality at high level.

  13. A spatially augmented reality sketching interface for architectural daylighting design.

    Science.gov (United States)

    Sheng, Yu; Yapo, Theodore C; Young, Christopher; Cutler, Barbara

    2011-01-01

    We present an application of interactive global illumination and spatially augmented reality to architectural daylight modeling that allows designers to explore alternative designs and new technologies for improving the sustainability of their buildings. Images of a model in the real world, captured by a camera above the scene, are processed to construct a virtual 3D model. To achieve interactive rendering rates, we use a hybrid rendering technique, leveraging radiosity to simulate the interreflectance between diffuse patches and shadow volumes to generate per-pixel direct illumination. The rendered images are then projected on the real model by four calibrated projectors to help users study the daylighting illumination. The virtual heliodon is a physical design environment in which multiple designers, a designer and a client, or a teacher and students can gather to experience animated visualizations of the natural illumination within a proposed design by controlling the time of day, season, and climate. Furthermore, participants may interactively redesign the geometry and materials of the space by manipulating physical design elements and see the updated lighting simulation. © 2011 IEEE Published by the IEEE Computer Society

  14. Multiobjective generalized extremal optimization algorithm for simulation of daylight illuminants

    Science.gov (United States)

    Kumar, Srividya Ravindra; Kurian, Ciji Pearl; Gomes-Borges, Marcos Eduardo

    2017-10-01

    Daylight illuminants are widely used as references for color quality testing and optical vision testing applications. Presently used daylight simulators make use of fluorescent bulbs that are not tunable and occupy more space inside the quality testing chambers. By designing a spectrally tunable LED light source with an optimal number of LEDs, cost, space, and energy can be saved. This paper describes an application of the generalized extremal optimization (GEO) algorithm for selection of the appropriate quantity and quality of LEDs that compose the light source. The multiobjective approach of this algorithm tries to get the best spectral simulation with minimum fitness error toward the target spectrum, correlated color temperature (CCT) the same as the target spectrum, high color rendering index (CRI), and luminous flux as required for testing applications. GEO is a global search algorithm based on phenomena of natural evolution and is especially designed to be used in complex optimization problems. Several simulations have been conducted to validate the performance of the algorithm. The methodology applied to model the LEDs, together with the theoretical basis for CCT and CRI calculation, is presented in this paper. A comparative result analysis of M-GEO evolutionary algorithm with the Levenberg-Marquardt conventional deterministic algorithm is also presented.

  15. Effect of Window Glazing on Colour Quality of Transmitted Daylight

    Directory of Open Access Journals (Sweden)

    Rajendra Dangol

    2017-12-01

    Full Text Available In this study, the colour quality of the daylight transmitted through different window glazing types is evaluated. The analysis considered four different types of window glazing: laminated, monolithic, coated and applied film glazing ranging in luminous transmittance from around 0.97 to <0.1. The spectral transmittance data of different window glazing types are taken from the International Glazing Data Base (IGDB, which is maintained by Lawrence Berkeley National Laboratories (LBNL. The study showed that the CIE CRI does not always seem to be the suitable method to predict the colour quality of daylight in building for particular situations. However, in the context of this study, the prediction of colour rendering properties of window glazing by other metrics such as Colour Quality Scale (version 9, Memory CRI, Ra,D65 (adjusted CRI metric with D65 as the reference illuminant performed better. For most of the daylit situations inside the building, the chromaticity difference criterion was not met. Judging the colour quality of such situations requires different method.

  16. Daylighting practices of the architectural industry (baseline results of a national survey)

    Energy Technology Data Exchange (ETDEWEB)

    Hattrup, M.P.

    1990-05-01

    A national survey of over 300 commercial design architects was conducted to develop baseline information on their knowledge, perceptions, and use of daylighting in commercial building designs. Pacific Northwest Laboratory conducted the survey for the US Department of Energy's (DOE) Office of Building and Community Systems (BCS). In the survey daylighting was defined as the intentional use of natural light as a partial substitute for artificially generated light. The results suggested that architects need to be educated about the true benefits of daylighting and the impacts it can have on a building's energy performance. Educational programs that will increase the architects' understanding and awareness of modern daylighting technologies and practices should be developed by utilities, stage agencies, and the federal government. If more architects can be made aware of the true effectiveness and positive attributes of daylighting systems and technologies, daylighting may be used in more commercial buildings. The results of the survey show that the more familiar architects feel they are with daylighting, the more they use daylighting. 3 refs., 19 tabs.

  17. Daylight-mediated photodynamic therapy of moderate to thick actinic keratoses of the face and scalp

    DEFF Research Database (Denmark)

    Wiegell, S.R.; Fabricius, S.; Philipsen, P.A.

    2012-01-01

    response rate and light dose in patients who received an effective light dose of > 3·5 J cm . Conclusions: Daylight-mediated PDT of moderate to thick AKs was less effective than daylight-mediated PDT of thin AKs especially in some centres. However, nearly all thicker lesions (grades II and III) were...

  18. Daylight and health: A review of the evidence and consequences for the built environment

    NARCIS (Netherlands)

    M.P.J. Aarts; Joost van Hoof; M.B.C. Aries

    2015-01-01

    Daylight has been associated with multiple health advantages. Some of these claims are associations, hypotheses or beliefs. This review presents an overview of a scientific literature search on the proven effects of daylight exposure on human health. Studies were identified with a search strategy

  19. Study of effect of daylight on Building User's Performance Based on Electroencephalograph Signal

    NARCIS (Netherlands)

    Mangkuto, R.A.; Soelami, F.X.N.; Suprijanto, S.

    2009-01-01

    The use of daylighting in building nowadays has become one alternative to save electric energy consumption, particularly during daytime. Daylight is not only useful for reducing cost from electric light sources, but also give benefits both physiologically and psychologically for building users.

  20. Daylighting Concepts for University Libraries and Their Influences on Users' Satisfaction

    Science.gov (United States)

    Kilic, Didem Kan; Hasirci, Deniz

    2011-01-01

    Daylighting, a controlled architectural tool that influences users' perception and behavior, in university libraries and their influences on users' preference and satisfaction was examined in this study. The effects of daylighting in coordination with visual comfort, on university library users were measured in relation to four environmental…

  1. An Exploration into Integrating Daylight and Artificial Light via an Observational Instrument

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Søndergaard, Karin

    2015-01-01

    An Exploration into Integrating Daylight and Artificial Light via an Observational Instrument Daylight is dynamic and dependent upon weather conditions; unfolding with both subtle and dramatic variations in qualities of light. Through a building’s apertures, daylight creates a connection between...... abstract and blurred phenomena, these diffused luminous reflections rouse us into interactions with the world. In this book we are interested in identifying the qualitative parameters involved in the integration of dynamic artificial lighting and daylight; the latter being already highly dynamic by nature...... that examine how the dynamic artificial lighting in the observational instrument unfolds during the changing of the daylight situations that are generated by the weather outside. This research employs the concept of coupling between interior and exterior, in order to identify a spectrum of design parameters...

  2. Daylight-mediated photodynamic therapy of basal cell carcinomas - an explorative study

    DEFF Research Database (Denmark)

    Wiegell, S R; Skødt, V; Wulf, H C

    2014-01-01

    BACKGROUND: Studies have shown that daylight-photodynamic therapy (PDT) is an effective treatment of actinic keratoses, nearly pain free and more convenient for both the clinics and patients. Treatment of basal cell carcinomas (BCCs) is another main indication for PDT. OBJECTIVES: The aim...... of this open, uncontrolled, prospective explorative study was to evaluate the efficacy of daylight-PDT for BCCs. METHODS: Twenty-one patients with a total of 32 BCCs located in the face, scalp, chest, back and lower leg received one cycle of daylight-methyl aminolevulinate (MAL)-PDT, consisting of two...... treatments 1 week apart. After sunscreen application and lesion preparation, MAL was applied and patients exposed themselves to daylight for 2½ h. Daylight exposure was monitored with a wrist-borne dosimeter. RESULTS: At 3-month follow-up, complete response was seen in 30 lesions (94%) and in 19 patients (90...

  3. Detailed simulations of lighting conditions in office rooms lit by daylight and artificial light

    DEFF Research Database (Denmark)

    Iversen, Anne

    In this thesis the effect on the annual artificial lighting demand is investigated by employing detailed simulations of lighting conditions in office rooms lit by daylight and artificial. The simulations of the artificial lighting demand is accomplished through daylight simulations in Radiance....... The detailed simulations includes studies of the resolution of different weather data sets in climate-based daylight modeling. Furthermore, influence of the electrical lighting demand by simulating with dynamic occupancy patterns is studied. Finally the thesis explores the influence of obstructions in an urban...... canyon on the daylight availability within the buildings, and hence on the energy consumption for artificial lights. The results from the thesis demonstrates that the effect on the outcome of the daylight simulations when simulating with typical weather data files for the location of Copenhagen...

  4. STRATEGI DAYLIGHTING PADA BANGUNAN MULTI-LANTAI DI ATAS DAN DI BAWAH PERMUKAAN TANAH

    Directory of Open Access Journals (Sweden)

    Danny Santoso Mintorogo

    1999-01-01

    Full Text Available One of the common factor for Energy Saving on buildings has dealed a lot with the lightings on building, especially for multi level floors above and below grade. In order for saving energy on lightings, many daylighting strategies on multi floors building are being used and under-developed by many architects. This paper discusses the strategies of the daylighting techniques on multi floors building both above and below grade Abstract in Bahasa Indonesia : Strategi hemat energi sangat erat hubungan dengan faktor penerangan dalam bangunan, lebih-lebih pada bangunan berlantai banyak diatas atau dibawah permukaan tanah. Untuk menghemat pemakaian energi listrik dari penerangan ini, maka strategi-strategi penerangan alami "Daylighting" terus dikembangkan. Tulisan ini bertujuan memaparkan berbagai strategi daylighting pada bangunan yang berlantai banyak yang dibangun diatas maupun dibawah permukaan tanah. Kata kunci : daylighting, energi

  5. Seasonality in trauma admissions - Are daylight and weather variables better predictors than general cyclic effects?

    Science.gov (United States)

    Røislien, Jo; Søvik, Signe; Eken, Torsten

    2018-01-01

    Trauma is a leading global cause of death, and predicting the burden of trauma admissions is vital for good planning of trauma care. Seasonality in trauma admissions has been found in several studies. Seasonal fluctuations in daylight hours, temperature and weather affect social and cultural practices but also individual neuroendocrine rhythms that may ultimately modify behaviour and potentially predispose to trauma. The aim of the present study was to explore to what extent the observed seasonality in daily trauma admissions could be explained by changes in daylight and weather variables throughout the year. Retrospective registry study on trauma admissions in the 10-year period 2001-2010 at Oslo University Hospital, Ullevål, Norway, where the amount of daylight varies from less than 6 hours to almost 19 hours per day throughout the year. Daily number of admissions was analysed by fitting non-linear Poisson time series regression models, simultaneously adjusting for several layers of temporal patterns, including a non-linear long-term trend and both seasonal and weekly cyclic effects. Five daylight and weather variables were explored, including hours of daylight and amount of precipitation. Models were compared using Akaike's Information Criterion (AIC). A regression model including daylight and weather variables significantly outperformed a traditional seasonality model in terms of AIC. A cyclic week effect was significant in all models. Daylight and weather variables are better predictors of seasonality in daily trauma admissions than mere information on day-of-year.

  6. Seasonality in trauma admissions – Are daylight and weather variables better predictors than general cyclic effects?

    Science.gov (United States)

    Søvik, Signe; Eken, Torsten

    2018-01-01

    Background Trauma is a leading global cause of death, and predicting the burden of trauma admissions is vital for good planning of trauma care. Seasonality in trauma admissions has been found in several studies. Seasonal fluctuations in daylight hours, temperature and weather affect social and cultural practices but also individual neuroendocrine rhythms that may ultimately modify behaviour and potentially predispose to trauma. The aim of the present study was to explore to what extent the observed seasonality in daily trauma admissions could be explained by changes in daylight and weather variables throughout the year. Methods Retrospective registry study on trauma admissions in the 10-year period 2001–2010 at Oslo University Hospital, Ullevål, Norway, where the amount of daylight varies from less than 6 hours to almost 19 hours per day throughout the year. Daily number of admissions was analysed by fitting non-linear Poisson time series regression models, simultaneously adjusting for several layers of temporal patterns, including a non-linear long-term trend and both seasonal and weekly cyclic effects. Five daylight and weather variables were explored, including hours of daylight and amount of precipitation. Models were compared using Akaike’s Information Criterion (AIC). Results A regression model including daylight and weather variables significantly outperformed a traditional seasonality model in terms of AIC. A cyclic week effect was significant in all models. Conclusion Daylight and weather variables are better predictors of seasonality in daily trauma admissions than mere information on day-of-year. PMID:29425210

  7. Alternatives to Outdoor Daylight Illumination for Photodynamic Therapy—Use of Greenhouses and Artificial Light Sources

    Directory of Open Access Journals (Sweden)

    Catharina M. Lerche

    2016-02-01

    Full Text Available Daylight-mediated photodynamic therapy (daylight PDT is a simple and pain free treatment of actinic keratoses. Weather conditions may not always allow daylight PDT outdoors. We compared the spectrum of five different lamp candidates for indoor “daylight PDT” and investigated their ability to photobleach protoporphyrin IX (PpIX. Furthermore, we measured the amount of PpIX activating daylight available in a glass greenhouse, which can be an alternative when it is uncomfortable for patients to be outdoors. The lamps investigated were: halogen lamps (overhead and slide projector, white light-emitting diode (LED lamp, red LED panel and lamps used for conventional PDT. Four of the five light sources were able to photobleach PpIX completely. For halogen light and the red LED lamp, 5000 lux could photobleach PpIX whereas 12,000 lux were needed for the white LED lamp. Furthermore, the greenhouse was suitable for daylight PDT since the effect of solar light is lowered only by 25%. In conclusion, we found four of the five light sources and the greenhouse usable for indoor daylight PDT. The greenhouse is beneficial when the weather outside is rainy or windy. Only insignificant ultraviolet B radiation (UVB radiation passes through the greenhouse glass, so sun protection is not needed.

  8. Evaluation of daylight intensity for sustainbility in residential buildings in cantonment cottages multan

    International Nuclear Information System (INIS)

    Yousuf, S.; Maqsood, S.

    2017-01-01

    Day lighting is a useful and effective source of energy savings and visual comforts in buildings. Occupants expect good daylight in their living spaces for better living environment. The quality and quantity of natural light entering in to a building depend on both internal and external factors. Daylight strategies basically depend on the accessibility of natural light that is determined by the latitude of the building site and the conditions surrounding the building. Daylight provides lighting energy and energy demand reduction during peak utility hours. Bringing daylight into a building that displaces electric lighting and provides sufficient illumination is the greenest way to light a building presently. This research, aims at analyzing the daylight intensity in residential buildings in Cantonment Cottages Multan which is one of the hottest and progresse city of Pakistan. The intensity of daylight can be expressed in the terms of luminance and daylight factor. In this research, the 5 and 7 marla houses in Cantt Cottages in Multan were selected. The device lux meter was used for measuring intensity with which the brightness appears to the human eye. The readings were taken by placing Lux Meter at the center and near windows in each building component at 2-4 pm. In order to evaluate the daylight intensity, the measured luminance in each component of building is compared with the standard illuminance as per recommendation of CIBSE (Chartered Institute of Building Service Engineers). After investigation, it has been found that daylight factor is much higher than the standard values as per recommended by CIBSE. The design parameters including building orientation, glazing area, room size to window opening ratio etc. is not appropriate with respect to sustainable design. (author)

  9. Alternatives to Outdoor Daylight Illumination for Photodynamic Therapy—Use of Greenhouses and Artificial Light Sources

    DEFF Research Database (Denmark)

    Lerche, Catharina; Heerfordt, Ida M; Heydenreich, Jakob

    2016-01-01

    to photobleach protoporphyrin IX (PpIX). Furthermore, we measured the amount of PpIX activating daylight available in a glass greenhouse, which can be an alternative when it is uncomfortable for patients to be outdoors. The lamps investigated were: halogen lamps (overhead and slide projector), white light...... was suitable for daylight PDT since the effect of solar light is lowered only by 25%. In conclusion, we found four of the five light sources and the greenhouse usable for indoor daylight PDT. The greenhouse is beneficial when the weather outside is rainy or windy. Only insignificant ultraviolet B radiation...

  10. Performance of a daylight redirecting glass shading system demonstration in an office building

    DEFF Research Database (Denmark)

    Appelfeld, David; Svendsen, Svend; Traberg-Borup, Steen

    2011-01-01

    This paper evaluates the daylighting performance of a prototype external dynamic integrated shading and light redirecting system. The demonstration project was carried out on a building with an open-plan office. The prototype and original façades were placed on the same floor with the same...... orientation and similar surroundings. The existing façade was used as the reference for measurements and simulations. The focus of this research project was to employ available simulation tools for the system performance evaluation. This was accompanied by measurements of the daylight conditions...... in the investigated space. The prototype system improved daylighting conditions compared to the existing shading system....

  11. Fatal alcohol-related traffic crashes increase subsequent to changes to and from daylight savings time.

    Science.gov (United States)

    Hicks, G J; Davis, J W; Hicks, R A

    1998-06-01

    On the hypothesis that sleepiness and alcohol interact to increase the risk of alcohol-related traffic fatalities, the percentages of alcohol-related fatal traffic crashes were assessed for the entire state of New Mexico for the years 1989-1992, for each of the seven days that preceded the changes to and from Daylight Savings Time and for each of the 14 days which followed the changes to and from Daylight Savings Time. Consistent with our hypothesis the percentage of alcohol-related fatal crashes increased significantly during the first seven days after these changes in Daylight Savings Time.

  12. Theoretical and experimental analysis of daylight performance for various shading systems

    Energy Technology Data Exchange (ETDEWEB)

    Tsangrassoulis, A [Group Building Enviromental Studies, Lab. of Meteorology, Dept. of Applied Physics, Univ. of Athens (Greece); Santamouris, M [Group Building Enviromental Studies, Lab. of Meteorology, Dept. of Applied Physics, Univ. of Athens (Greece); Asimakopoulos, D [Group Building Enviromental Studies, Lab. of Meteorology, Dept. of Applied Physics, Univ. of Athens (Greece)

    1997-12-31

    The daylight coefficient approach is used for the theoretical analysis of various shading systems. Once a set of these coefficients has been calculated, it is very easy to calculate illuminance in the interior of a room under various sky luminance distributions. The present paper examines a method based on daylight coefficients to evaluate daylight in the interior of a room. The method is compared with existing radiosity and ray-tracing methods. The examined method is experimentaly validated using measurements obtained in a PASSYS test-cell equipped with shading devices. (orig.)

  13. IEA Task 31. Daylighting Buildings in the 21{sup st} Century

    Energy Technology Data Exchange (ETDEWEB)

    Scartezzini, J.-L.; Morel, N.; Andersen, M.; Lindelhoef, D.

    2006-02-15

    This report for the Swiss Federal Office of Energy (SFOE) takes a look at work being carried out within the framework of the International Energy Agency's Solar Heating and Cooling Programme, Task 31 concerning the daylighting of buildings. Research activities in the task's four subtasks, user perspectives and requirements, integration and optimisation of daylighting systems, daylighting design tools and performance tracking network and design support groups are reported on. Objectives, projects and outcomes of each subtask are presented. Swiss contributions to the work done in these subtasks are reviewed and main achievements due to Swiss contributions are listed. Practical examples are quoted.

  14. A simple tool to evaluate the effect of the urban canyon on daylight level and energy demand in the early stages of building design

    DEFF Research Database (Denmark)

    Petersen, Steffen; Momme, Amalie Jin; Hviid, Christian Anker

    2014-01-01

    Daylight is a restricted resource in urban contexts. Rooms situated in an urban context often have a significant proportion of the sky and the sun blocked out by the urban building mass. The reduced direct daylight potential makes daylight reflected from outdoor surfaces an important daylight sou...... the impact of urban canyon parameters on indoor environment and energy performance....

  15. Workshop report and proposal for a new IEA Task: Daylight in buildings

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, P E; Johnsen, K

    1994-04-01

    The IEA workshop on Daylight in Buildings was held in Copenhagen on March 14-16, 1994. At the workshop, presentations were given on key topics as a basis for discussions by the experts participating in the meeting. The presentations and discussions covered a range of technical, architectural and amenity aspects of daylighting in buildings. A great interest in research collaboration on daylight was expressed, and it was agreed that plenty of work still needs to be done, and that the appropriate form of work would be an IEA Task. It was agreed that daylighting systems and control strategies should be evaluated and tested in test rooms, as well as in existing buildings as case studies. Furthermore, the workshop expressed that one of the best ways to realize and present the Task results to practice would be through a few demonstration buildings, build in different countries and under different climatic conditions. (EG)

  16. External perforated Solar Screens for daylighting in residential desert buildings: Identification of minimum perforation percentages

    KAUST Repository

    Sherif, Ahmed; Sabry, Hanan; Rakha, Tarek

    2012-01-01

    and Saudi Arabia, result in the admittance of direct solar radiation, which leads to thermal discomfort and the incidence of undesired glare. One type of shading systems that is used to permit daylight while controlling solar penetration is " Solar Screens

  17. Estimation of luminous efficacy of daylight and illuminance for composite climate

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Jamil M.; Tiwari, G.N. [Center for Energy Studies, Indian Institute of Technology, Hauz Khas, New Delhi-16 (India)

    2010-07-01

    This Daylighting is one of the basic components of passive solar building design and its estimation is essential. In India there are a few available data of measured illuminance as in many regions of the world. The Indian climate is generally clear with overcast conditions prevailing through the months of July to September, which provides good potential to daylighting in buildings. Therefore, an analytical model that would encompass the weather conditions of New Delhi was selected. Hourly exterior horizontal and slope daylight availability has been estimated for New Delhi using daylight modeling techniques based on solar radiation data. A model to estimate interior illuminance was investigated and validated using experimental hourly inside illuminance data of an existing skylight integrated vault roof mud house in composite climate of New Delhi. The interior illuminance model was found in good agreement with experimental value of interior illuminance.

  18. Impact of Extended Daylight Saving Time on National Energy Consumption Report to Congress

    Energy Technology Data Exchange (ETDEWEB)

    Belzer, D. B.; Hadley, S. W.; Chin, S-M.

    2008-10-01

    The Energy Policy Act of 2005 (Pub. L. No. 109-58; EPAct 2005) amended the Uniform Time Act of 1966 (Pub. L. No. 89-387) to increase the portion of the year that is subject to Daylight Saving Time. (15 U.S.C. 260a note) EPAct 2005 extended the duration of Daylight Saving Time in the spring by changing its start date from the first Sunday in April to the second Sunday in March, and in the fall by changing its end date from the last Sunday in October to the first Sunday in November. (15 U.S.C. 260a note) EPAct 2005 also called for the Department of Energy to evaluate the impact of Extended Daylight Saving Time on energy consumption in the United States and to submit a report to Congress. (15 U.S.C. 260a note) This report presents the results of impacts of Extended Daylight Saving Time on the national energy consumption in the United States. The key findings are: (1) The total electricity savings of Extended Daylight Saving Time were about 1.3 Tera Watt-hour (TWh). This corresponds to 0.5 percent per each day of Extended Daylight Saving Time, or 0.03 percent of electricity consumption over the year. In reference, the total 2007 electricity consumption in the United States was 3,900 TWh. (2) In terms of national primary energy consumption, the electricity savings translate to a reduction of 17 Trillion Btu (TBtu) over the spring and fall Extended Daylight Saving Time periods, or roughly 0.02 percent of total U.S. energy consumption during 2007 of 101,000 TBtu. (3) During Extended Daylight Saving Time, electricity savings generally occurred over a three- to five-hour period in the evening with small increases in usage during the early-morning hours. On a daily percentage basis, electricity savings were slightly greater during the March (spring) extension of Extended Daylight Saving Time than the November (fall) extension. On a regional basis, some southern portions of the United States exhibited slightly smaller impacts of Extended Daylight Saving Time on energy savings

  19. Daylighting and energy performance of a building for composite climate: An experimental study

    OpenAIRE

    Madhu Sudan; G.N. Tiwari

    2016-01-01

    The present study includes overall energy saving through thermal as well as daylighting for composite climate for the building known as SODHA BERS COMPLEX (SBC) situated at Varanasi, India. The building has been designed including all the passive concepts for thermal comfort as well daylighting to maximize the use of natural lighting for the occupants in day to day activities. This approach can be useful for multi-story building for rural and urban areas for both residential and commercial bu...

  20. Refractive integrated nonimaging solar collectors design and analysis of a novel solar-daylighting-technology

    OpenAIRE

    Pelegrini, Alexandre Vieira

    2009-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. A novel and original category of low-cost static solar-daylighting-collectors named Keywo solar energy, solar collectors, daylighting systems, nonimaging optics, Refractive Integrated Nonimaging Solar Collectors (RINSC) has been designed and thoroughly tested. The RINSC category is based on nonimaging optics and integrates several optical elements, such as prismatic arrays and light guides, i...

  1. Delight2 Daylighting Analysis in Energy Plus: Integration and Preliminary User Results

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, William L.; Hitchcock, Robert J.

    2005-04-26

    DElight is a simulation engine for daylight and electric lighting system analysis in buildings. DElight calculates interior illuminance levels from daylight, and the subsequent contribution required from electric lighting to meet a desired interior illuminance. DElight has been specifically designed to integrate with building thermal simulation tools. This paper updates the DElight capability set, the status of integration into the simulation tool EnergyPlus, and describes a sample analysis of a simple model from the user perspective.

  2. Impact of daylight saving time on the Chilean residential consumption

    International Nuclear Information System (INIS)

    Verdejo, Humberto; Becker, Cristhian; Echiburu, Diego; Escudero, William; Fucks, Emiliano

    2016-01-01

    Since 1970 Chile has had a Daylight Saving Time (DST) policy in order to reduce residential electricity consumption in the country. The time change was set for the first time by executive decree in 1970, and since that date it was applied every year without great changes until 2010. Since then, and to date, decrees have been set in order to increase the duration of the DST, arguing that there are reasons associated with energy savings that justify the extension of the measure that has been adopted by the authority in recent years. In the present study the impact of the application of DST in terms of decreased household electricity consumption is analyzed using two complementary methods, one based on a heuristic approach and the other using an econometric model. The results indicate that there is indeed a marginally small reduction in residential electricity consumption, although these results are not homogeneous throughout the country. - Highlights: • The impact of the application of DST is analyzed in Chilean distribution networks. • The results indicate that there is indeed a marginally small reduction in residential electricity consumption. • A total energy reduction is estimated based on the proposed methodology.

  3. The impact on energy consumption of daylight saving clock changes

    Energy Technology Data Exchange (ETDEWEB)

    Hill, S.I.; Desobry, F. [Department of Engineering, University of Cambridge (United Kingdom); Garnsey, E.W. [Institute for Manufacturing, University of Cambridge (United Kingdom); Chong, Y.-F. [IPA Energy and Water Consulting (United Kingdom)

    2010-09-15

    The focus of this work is an investigation of the effect of prevailing time regime on energy consumption. In particular we perform analysis demonstrating potential energy savings which could be obtained were Great Britain to maintain daylight savings time (DST) over winter, instead of reverting to Greenwich mean time (GMT). We review the literature on the effect of DST on energy consumption and show that this indicates a justification for considering the issue. Our headline result is in agreement with many related studies in that advancing the clock by an hour in winter would lead to energy savings of at least 0.3% of daily demand in Great Britain. In deriving this result we have adopted methodologies currently used in load prediction, in particular Support Vector Regression, to estimate energy demand on a half-hourly basis. Corresponding cost savings are found to be higher (due to the nonlinear increase of costs) and we find them to be on the order of 0.6% over the months considered. In terms of environmental impact we find the saving to be approximately equivalent to 450,000 ton of CO{sub 2}. In deriving these results we adopt a conservative approach such that we consider them lower bounds on any true savings. (author)

  4. Daylight-mediated photodynamic therapy in Spain: advantages and disadvantages.

    Science.gov (United States)

    Pérez-Pérez, L; García-Gavín, J; Gilaberte, Y

    2014-09-01

    Photodynamic therapy (PDT) is an option for the treatment of actinic keratosis, Bowen disease, and certain types of basal cell carcinoma. It is also used to treat various other types of skin condition, including inflammatory and infectious disorders. The main disadvantages of PDT are the time it takes to administer (both for the patient and for health professionals) and the pain associated with treatment. Daylight-mediated PDT has recently been reported to be an alternative to the conventional approach. Several studies have shown it to be similar in efficacy to and better tolerated than classic PDT for the treatment of mild to moderate actinic keratosis. Nevertheless, most of these studies are from northern Europe, and no data have been reported from southern Europe. The present article reviews the main studies published to date, presents the treatment protocol, and summarizes our experience with a group of treated patients. Copyright © 2013 Elsevier España, S.L.U. y AEDV. All rights reserved.

  5. The impact on energy consumption of daylight saving clock changes

    International Nuclear Information System (INIS)

    Hill, S.I.; Desobry, F.; Garnsey, E.W.; Chong, Y.-F.

    2010-01-01

    The focus of this work is an investigation of the effect of prevailing time regime on energy consumption. In particular we perform analysis demonstrating potential energy savings which could be obtained were Great Britain to maintain daylight savings time (DST) over winter, instead of reverting to Greenwich mean time (GMT). We review the literature on the effect of DST on energy consumption and show that this indicates a justification for considering the issue. Our headline result is in agreement with many related studies in that advancing the clock by an hour in winter would lead to energy savings of at least 0.3% of daily demand in Great Britain. In deriving this result we have adopted methodologies currently used in load prediction, in particular Support Vector Regression, to estimate energy demand on a half-hourly basis. Corresponding cost savings are found to be higher (due to the nonlinear increase of costs) and we find them to be on the order of 0.6% over the months considered. In terms of environmental impact we find the saving to be approximately equivalent to 450,000 ton of CO 2 . In deriving these results we adopt a conservative approach such that we consider them lower bounds on any true savings.

  6. Combining annual daylight simulation with photobiology data to assess the relative circadian efficacy of interior spaces

    Energy Technology Data Exchange (ETDEWEB)

    Pechacek, C.S.; Andersen, M. [Massachusetts Inst. of Technology, Cambridge, MA (United States). Dept. of Architecture, Building Technology; Lockley, S.W. [Harvard Medical School, Boston, MA (United States). Div. of Sleep Medicine, Brigham and Women' s Hospital

    2008-07-01

    This paper addressed the issue of hospital design and the role of daylight in patient health care. It presented a new approach for integrating empirical data and findings in photobiology into the performance assessment of a space, thus combining both visual and health-related criteria. Previous studies have reported significant health care outcomes in daylit environments, although the mechanism and photoreceptor systems controlling these effects remain unknown. This study focused on furthering the previous studies beyond windows to describing the characteristics of daylight that may promote human health by providing daylighting for the appropriate synchronization of circadian rhythms, and then make specific daylighting recommendations, grounded in biological findings. In particular, this study investigated the use of daylight autonomy (DA) to simulate the probabilistic and temporal potential of daylight for human health needs. Results of photobiology research were used to define threshold values for lighting, which were then used as goals for simulations. These goals included spectrum, intensity and timing of light at the human eye. The study investigated the variability of key architectural decisions in hospital room design to determine their influence on achieving the goals. The simulations showed how choices in building orientation, window size, user-window position and interior finishes affect the circadian efficacy of a space. Design decisions can improve or degrade the health potential for the space considered. While the findings in this research were specific to hospitals, the results can be applied to other building types such as office buildings and residences. 33 refs., 7 figs.

  7. Impacts of orientation on daylighting in high-rise office buildings in Malaysia

    Directory of Open Access Journals (Sweden)

    AbdolHamid Mahdavi

    2015-12-01

    Full Text Available Orientation is one of the important factors in building design to use daylight and ‎conserve energy. Well-orientated buildings maximise daylight reception through ‎building facades and reduce the need for artificial lighting. Reasonable daylighting usage in office buildings is an important part of an architect’s designing process, which leads to lesser electricity consumption as well as providing a visual and thermal comfort for the occupants. Orientation is an important factor in passive design strategies. This paper focuses on the orientation effect on daylighting into office rooms. The research method of this study was simulation which is performed on a hypothetical model on a 25 storey high-rise office building in Malaysia. All simulations were carried out in the IES-VE software that uses RADIANCE program for illuminance calculations. To evaluate the daylight in various conditions, a new index SAZ was introduced which assesses daylight factor (DF and absolute Lux. Results showed similar SAZ in CIE overcast sky in various orientations; whereas, in sunny sky due to sun path in Malaysia, different results showed northern and southern rooms have the best illuminance distribution. However, the similar window form and size in four orientations lead to more energy consumption for artificial lighting and cooling loads.

  8. Performance of Anidolic Daylighting Systems in tropical climates - Parametric studies for identification of main influencing factors

    Energy Technology Data Exchange (ETDEWEB)

    Linhart, Friedrich; Scartezzini, Jean-Louis [Solar Energy and Building Physics Laboratory (LESO-PB), Swiss Federal Institute of Technology in Lausanne (EPFL), 1015 Lausanne (Switzerland); Wittkopf, Stephen K. [School of Design and Environment, Department of Architecture, National University of Singapore, 4 Architecture Drive, Singapore 117566 (Singapore)

    2010-07-15

    Making daylight more available in buildings is highly desirable, not only for reasons of energy-efficiency, but also for improvement of occupants' health and well-being. Core-daylighting, that is daylight provision in areas situated at considerable distances from facades and windows, is currently one of the main challenges in sustainable building design. Anidolic Daylighting Systems (ADSs) are one very promising technology in the field of core-daylighting, but commercial solutions that are not only well-performing but also financially competitive are not yet widely available. This article presents results of parametric studies on Anidolic Integrated Ceilings (AICs), a special type of ADS, for identification of main influencing factors. The article describes a reliable method for simulating ADS and AIC performance under given sky conditions. Various simulation results for the example location Singapore are discussed in detail, it is concluded that the main influencing factors are coating material, system dimensions and external obstruction, and those influencing factors' potential impacts are quantified. It is shown that AIC overall efficiencies can reach up to almost 50% in Singapore. The essentially new results presented in this article can be of great help to architects, engineers and scientists in the future, when it comes to precisely dimensioning ADS for various buildings and daylight conditions. (author)

  9. Flat Optical Fiber Daylighting System with Lateral Displacement Sun-Tracking Mechanism for Indoor Lighting

    Directory of Open Access Journals (Sweden)

    Ngoc Hai Vu

    2017-10-01

    Full Text Available An essential impact which can improve the indoor environment and save on power consumption for artificial lighting is utilization of daylight. Optical fiber daylighting technology offers a way to use direct daylight for remote spaces in a building. However, the existing paradigm based on the precise orientation of sunlight concentrator toward the Sun is very costly and difficult to install on the roof of buildings. Here, we explore an alternative approach using mirror-coated lens array and planar waveguide to develop a flat optical fiber daylighting system (optical fiber daylighting panel with lateral displacement Sun-tracking mechanism. Sunlight collected and reflected by each mirror-coated lens in a rectangular lens array is coupled into a planar waveguide using cone prisms placed at each lens focus. This geometry yields a thin, flat profile for Sunlight concentrator. Our proposed concentrating panel can be achieved with 35 mm thickness while the concentrator’s width and length are 500 mm × 500 mm. The commercial optical simulation tool (LightToolsTM was used to develop the simulation models and analyze the system performance. Simulation results based on the designed system demonstrated an optical efficiency of 51.4% at a concentration ratio of 125. The system can support utilizing a lateral displacement Sun-tracking system, which allows for replacing bulky and robust conventional rotational Sun-tracking systems. This study shows a feasibility of a compact and inexpensive optical fiber daylighting system to be installed on the roof of buildings.

  10. Application and Computer Analysis of Solar Systems for the Indoor Daylighting

    International Nuclear Information System (INIS)

    Makhmudov, Is Kandar

    2010-02-01

    A steady increase of energy costs and ever growing environmental concerns in recent years have forced scientists to look for new methods of energy utilization. To resolve these dire problems, the application of renewable energy sources has been considered in various human activities in every sector of society. One of them is the development of solar daylighting systems for residential and commercial buildings, which can improve building energy efficiency and create comfortable indoor environment. Electric lighting represents up to 30 % of building electricity consumption. Therefore, using sunlight in indoor daylighting can significantly reduce electricity consumption in residential and commercial buildings. Moreover, daylight is an important factor in visual environment and improving human well-being. In last decades, different approaches to the design of solar daylighting systems have resulted in various innovative solutions to efficiently introduce natural light in buildings. But their efficiency and cost are still one of primary obstacles in the wider development and distribution of solar daylighting systems. In this study, we investigated the performance of a new solar concentrator system for indoor illumination. The solar concentrator system consists of 30 cm dish concentrators, high precision solar trackers, optical fibers and diffusers for a light distribution. In order to assess the daylighting system's efficiency, there were carried out several experimental measurement series. One of them was an application of our solar daylighting system to two standard classrooms with south- and north-oriented windows in Jeju city, Korea. At the same time classrooms were modeled by using ECOTECT and exported to RADIANCE for daylighting simulations. Results from the measurements and simulations were analyzed comprehensively to establish the reliability of the modeling process. Following this, we modeled both classrooms with the above mentioned daylighting systems

  11. Simulation of Daylighting Conditions in a Virtual Underground City

    Directory of Open Access Journals (Sweden)

    Cristiano Merli Alcini

    2015-06-01

    Full Text Available From the Piranesi fantastic architectures to the animation movies and video games of the last thirty years, a new design approach has been introduced and developed: the design of the virtual space. Designing the "virtual" means experiencing a multidisciplinary approach where architecture, engineering, and urban planning meet the new horizons of information and communication technology. This study is focused on virtual space, which is an underground city. Mankind have always made and used underground environments: the possibilities of unlimited spaces to potential development, the reduced needs for raw materials for the construction and the protection from outdoor weather are some of the reasons that prompted humans to the realization of underground spaces in the past. These reasons and the availability of innovative technologies could encourage a breakthrough in the realization of new underground environments. A recent example is represented by the Underground City of Montreal (RÉSO. We present the architectural design of a virtual underground city, which is called Arch[ane], and its evaluation. The underground city is modular and the studied module is composed of eight floors with a total depth of 400 m and dimensions of 800 m × 800 m. The study comprises the evaluation of the effect of sunlight on each eight floors of the city. Daylighting simulations were performed considering different cities at different latitudes, days, and hours. The results have shown that the particular design of the underground city with skylights gives significant values of illuminance at a certain depth. Furthermore, the simulation results show how huge can be the potentialities of software to simulate extremely big environments.

  12. A randomized, multicentre study of directed daylight exposure times of 11/2 vs. 21/2 h in daylight-mediated photodynamic therapy with methyl aminolaevulinate in patients with multiple thin actinic keratoses of the face and scalp

    DEFF Research Database (Denmark)

    Wiegell, S.R.; Fabricius, S.; Philipsen, P.A.

    2011-01-01

    , time of day or time of year during which the treatment was performed. Treatment was well tolerated, with a mean ± SD maximal pain score of 1·3 ± 1·5. Conclusions: Daylight-mediated MAL-PDT is an effective, convenient and nearly pain-free treatment for patients with multiple thin AKs. Daylight-mediated......, the inconvenience of clinic attendance and discomfort during therapy are significant drawbacks. Daylight-mediated PDT could potentially reduce these and may serve as an alternative to conventional PDT. Objectives: To compare the efficacy of methyl aminolaevulinate (MAL)-PDT with 11/2 vs. 21/2 h of daylight exposure...

  13. Glazing façade modules : daylighting performance simulation for Bragança, Coimbra, Évora and Faro

    OpenAIRE

    Sacht, Helenice Maria; Bragança, L.; Almeida, Manuela Guedes de; Caram, Rosana

    2012-01-01

    The daylighting performance improvement is one better strategy to reduce the artificial lighting consumption in buildings and obviously requires solar radiation from the exterior. Daylighting comes not only from direct sunlight but also from illumination provided by the sky on overcast days. Particular attention must be given to daylighting while designing a building when the aim is to maximize visual comfort or to reduce energy consumption. Visual comfort of glazing façades is a fundamental ...

  14. Architecture, energy and daylight. Study of seven buildings; Arkitektur, energi og dagslys. Undersoegelse af syv bygninger

    Energy Technology Data Exchange (ETDEWEB)

    Christoffersen, J.; Petersen, E.; Svensson, O.

    2001-07-01

    The purpose of this research project was to enhance the designer's knowledge for designing buildings, rooms and window openings which utilise daylight in such a way that aesthetic and functional requirements can be met and energy consumption for electric lighting can be reduced at the same time. It was not the purpose of the project to develop guidelines but only to demonstrate how good daylight conditions and energy conservation can be achieved. The daylight conditions in the seven selected buildings were registered and assessed by the panel on two field trips in the spring of 1999. During these visits, the research team registered the location of rooms, their orientation, windows, artificial lighting etc. After the field trips, the buildings were photographed and the research group performed measurements and analyses of the lighting conditions in the rooms. However, the quality of daylight cannot be determined based only on measurements. The four professionals therefore supplemented the measurements with a subjective evaluation. The study of these seven buildings led to a number of results that must be assumed to be generally valid. A main result is that good daylight conditions in no way prevents or impedes the creation of good architecture. On the contrary, quality of daylight creates both functional as well as aesthetically satisfactory architecture. In all the investigated buildings, the ratio of glass areas to floor area is highter than 10%. In Denmark, this ratio would ensure reasonable daylight access and a view out. However, when size of glass area and daylight measurements are compared, the relationship between them is not straight-forward. The quantity and quality of daylight in buildings depend on other factors too, such as the depth of window openings, solar shading devices, opposite buildings, outdoor vegetation etc. The study points out that there are no standard solutions of how to design facades and window openings which satisfy all

  15. The impact of windows and daylight on acute-care nurses' physiological, psychological, and behavioral health.

    Science.gov (United States)

    Zadeh, Rana Sagha; Shepley, Mardelle McCuskey; Williams, Gary; Chung, Susan Sung Eun

    2014-01-01

    To investigate the physiological and psychological effects of windows and daylight on registered nurses. To date, evidence has indicated that appropriate environmental lighting with characteristics similar to natural light can improve mood, alertness, and performance. The restorative effects of windows also have been documented. Hospital workspaces generally lack windows and daylight, and the impact of the lack of windows and daylight on healthcare employees' well being has not been thoroughly investigated. Data were collected using multiple methods with a quasi-experimental approach (i.e., biological measurements, behavioral mapping, and analysis of archival data) in an acute-care nursing unit with two wards that have similar environmental and organizational conditions, and similar patient populations and acuity, but different availability of windows in the nursing stations. Findings indicated that blood pressure (p windows and daylight. A possible micro-restorative effect of windows and daylight may result in lowered blood pressure and increased oxygen saturation and a positive effect on circadian rhythms (as suggested by body temperature) and morning sleepiness. Critical care/intensive care, lighting, nursing, quality care, work environment.

  16. Daylighting performance evaluation of a bottom-up motorized roller shade

    Energy Technology Data Exchange (ETDEWEB)

    Kapsis, K.; Athienitis, A.K.; Zmeureanu, R.G. [Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC (Canada); Tzempelikos, A. [School of Civil Engineering, Purdue University, West Lafayette, IN (United States)

    2010-12-15

    This paper presents an experimental and simulation study for quantifying the daylighting performance of bottom-up roller shades installed in office spaces. The bottom-up shade is a motorized roller shade that opens from top to bottom operating in the opposite direction of a conventional roller shade, so as to cover the bottom part of the window, while allowing daylight to enter from the top part of the window, reaching deeper into the room. A daylighting simulation model, validated with full-scale experiments, was developed in order to establish correlations between the shade position, outdoor illuminance and work plane illuminance for different outdoor conditions. Then, a shading control algorithm was developed for application in any location and orientation. The validated model was employed for a sensitivity analysis of the impact of shade optical properties and control on the potential energy savings due to the use of daylighting. The results showed that Daylight Autonomy for the bottom-up shade is 8-58% higher compared to a conventional roller shade, with a difference of 46% further away from the facade, where the use of electric lighting is needed most of the time. The potential reduction in energy consumption for lighting is 21-41%. (author)

  17. Effectiveness of daylighting design and occupant visual satisfaction in a LEED gold laboratory building

    Energy Technology Data Exchange (ETDEWEB)

    Hua, Ying; Oswald, Anne [Department of Design and Environmental Analysis, Cornell University, Ithaca, NY 14853 (United States); Yang, Xiaodi [School of Architecture, Carnegie Mellon University, Pittsburgh, PA 15213 (United States)

    2011-01-15

    Using daylight as primary light source has been widely recognized as an important strategy to reduce building energy demand and enhance indoor environment quality. However, to design and operate a building to make full use of daylight, which is a dynamic light source, to meet diverse occupant needs remains a challenge. This paper reports a post-occupancy study of the visual environment in a laboratory building on a university campus, and puts a spotlight on the building occupants as it examines the effectiveness of the daylighting design and systems integration in creating a visual environment to support occupant comfort and satisfaction while reducing artificial lighting demand. Results show generally high satisfaction with daylit work environment and positive effect of the horizontal shading strategy. Issues about the integration between daylighting and electric lighting systems and level of occupant control are identified and discussed for improving the effectiveness of daylighting and enhancing the quality of the visual environment in the building of study. A multiple-tool methodology is developed and tested, which included occupant surveys, interviews, illuminance measurements, continuous data loggers, fisheye-lens camera and glare-identifying software, and documentation of spatial settings, systems features, and user behavior. (author)

  18. Performance of integrated systems of automated roller shade systems and daylight responsive dimming systems

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byoung-Chul; Choi, An-Seop; Jeong, Jae-Weon [Department of Architectural Engineering, Sejong University, Kunja-Dong, Kwangjin-Gu, Seoul (Korea, Republic of); Lee, Eleanor S. [Building Technologies Department, Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

    2011-03-15

    Daylight responsive dimming systems have been used in few buildings to date because they require improvements to improve reliability. The key underlying factor contributing to poor performance is the variability of the ratio of the photosensor signal to daylight workplane illuminance in accordance with sun position, sky condition, and fenestration condition. Therefore, this paper describes the integrated systems between automated roller shade systems and daylight responsive dimming systems with an improved closed-loop proportional control algorithm, and the relative performance of the integrated systems and single systems. The concept of the improved closed-loop proportional control algorithm for the integrated systems is to predict the varying correlation of photosensor signal to daylight workplane illuminance according to roller shade height and sky conditions for improvement of the system accuracy. In this study, the performance of the integrated systems with two improved closed-loop proportional control algorithms was compared with that of the current (modified) closed-loop proportional control algorithm. In the results, the average maintenance percentage and the average discrepancies of the target illuminance, as well as the average time under 90% of target illuminance for the integrated systems significantly improved in comparison with the current closed-loop proportional control algorithm for daylight responsive dimming systems as a single system. (author)

  19. Daylight saving time transitions and hospital treatments due to accidents or manic episodes

    Directory of Open Access Journals (Sweden)

    Lönnqvist Jouko

    2008-02-01

    Full Text Available Abstract Background Daylight saving time affects millions of people annually but its impacts are still widely unknown. Sleep deprivation and the change of circadian rhythm can trigger mental illness and cause higher accident rates. Transitions into and out of daylight saving time changes the circadian rhythm and may cause sleep deprivation. Thus it seems plausible that the prevalence of accidents and/or manic episodes may be higher after transition into and out of daylight saving time. The aim of this study was to explore the effects of transitions into and out of daylight saving time on the incidence of accidents and manic episodes in the Finnish population during the years of 1987 to 2003. Methods The nationwide data were derived from the Finnish Hospital Discharge Register. From the register we obtained the information about the hospital-treated accidents and manic episodes during two weeks before and two weeks after the transitions in 1987–2003. Results The results were negative, as the transitions into or out of daylight saving time had no significant effect on the incidence of accidents or manic episodes. Conclusion One-hour transitions do not increase the incidence of manic episodes or accidents which require hospital treatment.

  20. Daylight saving time transitions and hospital treatments due to accidents or manic episodes

    Science.gov (United States)

    Lahti, Tuuli A; Haukka, Jari; Lönnqvist, Jouko; Partonen, Timo

    2008-01-01

    Background Daylight saving time affects millions of people annually but its impacts are still widely unknown. Sleep deprivation and the change of circadian rhythm can trigger mental illness and cause higher accident rates. Transitions into and out of daylight saving time changes the circadian rhythm and may cause sleep deprivation. Thus it seems plausible that the prevalence of accidents and/or manic episodes may be higher after transition into and out of daylight saving time. The aim of this study was to explore the effects of transitions into and out of daylight saving time on the incidence of accidents and manic episodes in the Finnish population during the years of 1987 to 2003. Methods The nationwide data were derived from the Finnish Hospital Discharge Register. From the register we obtained the information about the hospital-treated accidents and manic episodes during two weeks before and two weeks after the transitions in 1987–2003. Results The results were negative, as the transitions into or out of daylight saving time had no significant effect on the incidence of accidents or manic episodes. Conclusion One-hour transitions do not increase the incidence of manic episodes or accidents which require hospital treatment. PMID:18302734

  1. Energy savings due to daylight and artificial lighting integration in office buildings in hot climate

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ashwal, Nagib T. [Sana' a University, Sana' a (Yemen); Budaiwi, Ismail M. [King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

    2011-07-01

    Reducing energy consumption while maintaining acceptable environmental quality in buildings has been a challenging task for building professionals. In office buildings, artificial lighting systems are a major consumer of energy and can significantly contribute to building cooling load. Furthermore, although reliable, artificial lighting does not necessarily provide the required quality of lighting. Significant improvement in lighting quality and energy consumption can be achieved by proper integration of daylight and artificial lighting. The objective of this study is to investigate the energy performance of office buildings resulting from daylight and artificial lighting integration in hot climates. A parametric analysis is conducted to find the impact of different window design parameters, including window area, height and glazing type, on building energy performance. Results have shown that as much as 35% reduction in lighting energy consumption and 13% reduction in total energy consumption can be obtained when proper daylighting and artificial lighting integration is achieved.

  2. Daylight Adaptive Shading Using Parametric Camshaft Mechanism for SOHO in Jakarta

    Directory of Open Access Journals (Sweden)

    Sjarifudin Firza Utama

    2014-03-01

    Full Text Available This research analyzes SOHO (Small Office Home Office which can adjust to the need of visual comfort for the users through natural daylighting and also can be adapted to standard requirements of 14 creative industry workspace in Jakartas. The method of the research is by simulating the SOHO unit with variation of shading opening angles in order to adapt to each unit. Analysis done to every shading opening angle to get the appropriate daylight intensity level which support the work activities in every unit for the whole day. In order for the shading to be able to adapt to the changing daylight condition, previously developed parametric camshaft mechanism was used. The study found that the visual comfort for SOHO with creative industries workers in Jakarta can be achieve by varying the shading opening angles between 15-75°.

  3. A Study on the Optimal Duration of Daylight Saving Time (DST in Korea

    Directory of Open Access Journals (Sweden)

    Byeong-Hee Mihn

    2009-09-01

    Full Text Available Daylight saving time aims at spending effective daylight in summer season. Korea had enforced daylight saving time twelve times from 1948 to 1988. Since 1988, it is not executed, but it is recently discussed the resumption of DST. In this paper, we investigate the trend of DST in other countries, review the history of DST in Korea, and suggest the optimal DST duration in terms of astronomical aspects (times of sunrise and sunset. We find that the starting day of DST in Korea is apt for the second Sunday in Mayor the second Sunday in April according to the time of sunrise or to the difference between Korean standard meridian and observer`s, respectively. We also discuss time friction that might be caused by time difference between DST and Korea Standard Time (KST.

  4. Determining daylight and view preferences from the use of blinds in apartments

    DEFF Research Database (Denmark)

    Petersen, Mads Dines

    2015-01-01

    preferences have significant influence on the daylight level and view as well as possible impact on the building’s energy consumption. Therefore, it is important to conduct further studies in the area in order to be able to design solutions that supports the user preferences better and through that improves...... for the inhabitants’ health and well-being, as well as the energy consumption. Present research is an important contribution, because of the increased knowledge about daylights impact on health and well-being as well as daylights impact on the energy consumption in our buildings. However, it is often seen...... that curtains or blinds, often close off new apartment buildings with large glass areas in dense urban context. Such observations indicate that there can be a discrepancy between the intentions of the design team or architect and the perception of the user. The paper presents the results of observations...

  5. Solar shading for low energy use and daylight quality in offices: Simulations, measurements and design tools

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, M.C.

    2001-11-01

    This thesis investigates the impact of solar shading devices on energy use and daylight quality in office rooms. The impact on energy use is analysed through computer simulations with the dynamic energy simulation program Derob-LTH while the impact on daylight quality is investigated through measurements in full-scale experimental office rooms and simulations with the program Radiance. This thesis also includes a literature review of research on solar shading as well as design tools to incorporate shading devices at an early stage in the design of buildings. This thesis indicates that, in cold countries, shading devices may provide more annual energy savings than any solar-protective (reflective, tinted) glazing and that the optimum glazing transmittance is orientation- and climate-dependent. For example, high annual energy savings are obtained on the south facade with higher transmittance glazings (compared with the east and west facade) because the potential for passive solar gain utilisation in the winter is high in comparison with the annual cooling demand. Exterior shading devices like awnings and overhangs may reduce the cooling demand dramatically but they are not suitable as daylight (glare) control devices. Devices like screens and venetian blinds are preferable because they cover the entire window area, which prevents sunlight patches in the room and the direct view of the bright sky. Screens and venetian blinds also reduce daylight in the room to levels that are suitable for computer work. However, it is essential that the screen is of a diffusing type since screens with a strong (specular) transmittance component result in poor daylight quality. The study on daylight quality also indicated that a screen transmittance of around 15 % may be optimum for a standard (3.5 by 6.0 m{sup 2}) south-oriented office room with a window covering around 25 % of the facade area (12 % of the floor area)

  6. Singapore's Zero-Energy Building's daylight monitoring system

    Energy Technology Data Exchange (ETDEWEB)

    Grobe, Lars; Wittkopf, Stephen; Pandey, Anupama Rana; Xiaoming, Yang; Seng, Ang Kian; Scartezzini, Jean-Louis; Selkowitz, Stephen

    2010-02-28

    A setup to monitor the daylighting performance of different glazing types in Singapore is presented. The glazing is installed in the facade of four dedicated testing chambers in BCAA's Zero Energy Building in Singapore. These test rooms are equipped with sensors that both record illuminances on the work plane, and luminances as seen by occupants. The physical and logical design of the monitoring system is presented. Criteria to assess the daylighting performance are introduced, and initial results of the work in progress are presented.

  7. Estimation Methodology for the Electricity Consumption with the Daylight- and Occupancy-Controlled Artificial Lighting

    DEFF Research Database (Denmark)

    Larsen, Olena Kalyanova; Jensen, Rasmus Lund; Strømberg, Ida Kristine

    2017-01-01

    Artificial lighting represents 15-30% of the total electricity consumption in buildings in Scandinavia. It is possible to avoid a large share of electricity use for lighting by application of daylight control systems for artificial lighting. Existing methodology for estimation of electricity...... consumption with application of such control systems in Norway is based on Norwegian standard NS 3031:2014 and can only provide results from a rough estimate. This paper aims to introduce a new estimation methodology for the electricity usage with the daylight- and occupancy-controlled artificial lighting...

  8. The effect of daylight saving time options on electricity consumption of Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Karasu, Servet [Rize University, Rize Vocational School, 53100, Rize (Turkey)

    2010-09-15

    Most of the developed countries in the world use Daylight Saving Time (DST) as an energy conservation method. This study focuses on the effects of DST on electrical lighting in the buildings in Turkey. Turkey might adjust its daylight saving time to decrease energy consumption. For this purpose, five scenarios are considered and compared to status quo. The scenario with a 30-minute forward shift to single DST from April to October, stands out as the best solution to conserve electricity across the entire country. The results of the study show that maximum saving is obtained in this scenario by at least 0.7% on the consumption of lighting electricity. (author)

  9. Economic feasibility of maximising daylighting of a standard office building with efficient electric lighting

    DEFF Research Database (Denmark)

    Fontoynont, Marc; Ramananarivo, Karine; Soreze, Thierry Silvio Claude

    2016-01-01

    This paper investigates the cost of developing various daylighting strategies for a standard office building in relation to their ability to reduce electric lighting consumption. The reference building design for this study corresponds to a typical configuration that minimises the construction...... costs and is typical of the French market. We have compared scenarios that entail moving service spaces to the periphery, increasing ceiling height and adding light wells of various shapes. These special features increased the proportion of the indoor area with sufficient daylight by up to 40...

  10. Application of a spectral sky in Radiance for daylighting calculations including non-image-forming light effects

    NARCIS (Netherlands)

    Khademagha, P.; Aries, M.B.C.; Rosemann, A.L.P.; van Loenen, E.J.

    2016-01-01

    Daylight is dynamic and rich in the blue part of the spectrum. To date, the spectral composition of daylight is ignored in sky models used in Radiance. Spectral sky composition is particularly important when non-image-forming (NIF) light effects are concerned, since the action spectrum for these

  11. Balancing energy and daylighting performances for envelope design: A new index and proposition of a case study in Hong Kong

    International Nuclear Information System (INIS)

    Xie, Jing Chao; Xue, Peng; Mak, Cheuk Ming; Liu, Jia Ping

    2017-01-01

    Highlights: •Daylighting and energy performances were studied simultaneously. •Energy demands of lighting and air-conditioning systems were both included. •Luminous comfort was quantified by Ave. DA 300 with the range from 29.6% to 57.8%. •Energy Daylight Rate was proposed as a simple multi-objective optimization approach. •Optimal scenarios for all directions were tested and chosen by EDR method. -- Abstract: Being healthy and energy saving have become two important principles of building development. Daylight is an influential factor with the characteristics of both photometry and radiometry. Irradiance brings solar heat gains that transfer to building cooling load, while illuminance provides a luminous environment and affects artificial lighting system at the same time. To balance the energy and daylighting performances, it is reasonable to minimize the environmental load under moderate comfort conditions. This study first quantified luminous comfort with a dynamic daylighting metric, average daylight autonomy (Ave. DA 300 ), from a questionnaire survey and simulation work. The benchmark of this metric should range from 29.6% to 57.8% for high-rise residential buildings. With this guideline, the Hong Kong public housing units is found that part of units lack of daylight due to the high building floor and density, while some units have potential to save energy by compromising daylighting performance. Therefore, a new index, energy daylight rate (EDR), is proposed to help decide the best scenario of envelope design for both daylighting and shading purposes. The results show that opening a secondary window is an efficient way to bring more light in and lengthening overhang is an efficient way to block excessive sunlight. This method and the new index are proved to have the ability to help defining proper building envelope design at the early stage.

  12. Hardware-in-the-Loop Modeling and Simulation Methods for Daylight Systems in Buildings

    Science.gov (United States)

    Mead, Alex Robert

    This dissertation introduces hardware-in-the-loop modeling and simulation techniques to the daylighting community, with specific application to complex fenestration systems. No such application of this class of techniques, optimally combining mathematical-modeling and physical-modeling experimentation, is known to the author previously in the literature. Daylighting systems in buildings have a large impact on both the energy usage of a building as well as the occupant experience within a space. As such, a renewed interest has been placed on designing and constructing buildings with an emphasis on daylighting in recent times as part of the "green movement.''. Within daylighting systems, a specific subclass of building envelope is receiving much attention: complex fenestration systems (CFSs). CFSs are unique as compared to regular fenestration systems (e.g. glazing) in the regard that they allow for non-specular transmission of daylight into a space. This non-specular nature can be leveraged by designers to "optimize'' the times of the day and the days of the year that daylight enters a space. Examples of CFSs include: Venetian blinds, woven fabric shades, and prismatic window coatings. In order to leverage the non-specular transmission properties of CFSs, however, engineering analysis techniques capable of faithfully representing the physics of these systems are needed. Traditionally, the analysis techniques available to the daylighting community fall broadly into three classes: simplified techniques, mathematical-modeling and simulation, and physical-modeling and experimentation. Simplified techniques use "rules-of-thumb'' heuristics to provide insights for simple daylighting systems. Mathematical-modeling and simulation use complex numerical models to provide more detailed insights into system performance. Finally, physical-models can be instrumented and excited using artificial and natural light sources to provide performance insight into a daylighting system

  13. Window design : visual and thermal consequences : analysis of the thermal and daylighting performance of windows

    NARCIS (Netherlands)

    Bergem-Jansen, P.M. van; Soeleman, R.S.

    1979-01-01

    Selected results of an analysis for the thermal and lighting requirements associated with windows in utility buildings are presented. This analysis concerns the effects of r¡indow size and shape, orientation and of different ways of supplementing the daylight by artifieial light for a typical office

  14. The Dynamics of Daylighting at a Residential College Building with the Internal Courtyard Arrangement

    Directory of Open Access Journals (Sweden)

    Adi Ainurzaman Jamaludin

    2015-11-01

    Full Text Available Dayasari residential college building was designed with the internal courtyard that allows for numerous implementations of bioclimatic design strategies, especially on daylighting. The field measurement was conducted at eight unoccupied student rooms, selected as samples to represent ten scenarios and orientations that concerned with the level of radiation and penetration of sunlight. This study reveals the contribution of the internal courtyard in the residential college which allows the daylight penetration at the corridor areas and interior of the rooms through the transom over the entrance door, up to ten hours daily. Different amounts of daylight were measured in specific room scenarios to suggest on the most comfortable indoor living space. The recorded mean value for indoor varied from 37 to 286 lux, while in the corridor area 192 to 3,848 lux. However, the use of the large overhangs over the windows, wall openings in the room and trees with large canopy in the landscape setting should critically justify when the adequacy of daylight was drastically reduced in certain rooms.

  15. The characterisation of the daylighting properties of special glazings and solar shading devices

    NARCIS (Netherlands)

    Dijk, H.A.L. van; Bakker, L.G.

    1998-01-01

    Within the EU DGXII R&D Programme JOULE a project, called REVIS. started in 1998 and will be completed within 2.5 years, with the objective to develop detailed daylight product information of novel products of glazings and solar shading devices. This involves a test procedure, definition of product

  16. Estimation of exterior vertical daylight for the humid tropic of Kota Kinabalu city in East Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Djamila, Harimi; Ming, Chu Chi; Kumaresan, Sivakumar [School of Engineering and Information Technology, Universiti Malaysia Sabah, Locked Bag No. 2073, 88999 Kota Kinabalu, Sabah (Malaysia)

    2011-01-15

    In tropical regions natural daylight has been a fundamental factor in building design. It is the most efficient way of lighting a building in the daytime and has a great potential for energy conservation in buildings. In Malaysia there are a limited available data of measured illuminance which is the case of several regions in the tropics. Using established models it is possible to predict the luminous efficacy and then estimate the monthly mean hourly exterior illuminance. In this study two different models were chosen. The Perez and Du Mortier-Perraudeau-Page-Littlefair models were selected for the prediction of hourly exterior horizontal illuminance for the city of Kota Kinabalu in East Malaysia. Comparison between the two models were made. The vertical hourly illuminance was predicted also using Perez approach. The potentiality of daylight in four orientations was discussed. This study highlights the importance of Sunpath diagram on daylight illuminance during the conceptual design stage. The results in this study is hoped to contribute further insight into the potentiality of daylighting of tropical sky. (author)

  17. PULSE: Integrated Parametric Modeling for a Shading System : From Daylight Optimization to Additive Manufacturing

    NARCIS (Netherlands)

    Teeling, M.V.M.T.; Turrin, M.; de Ruiter, P.; Turrin, Michela; Peters, Brady; O'Brien, William; Stouffs, Rudi; Dogan, Timur

    2017-01-01

    This paper presents a parametric approach to an integrated and performance-oriented design, from the conceptual design phase towards materialization. The novelty occurs in the use of parametric models as a way of integrating multidisciplinary design constraints, from daylight optimization to the

  18. OPTIMIZATION STUDY OF VISUAL COMFORT AND DAYLIGHT AVAILABILITY AT CADL ITB

    Directory of Open Access Journals (Sweden)

    SIREGAR Mhd. Akbar Anthony

    2016-12-01

    Full Text Available One way to reduce energy consumption in buildings is to use daylighting. However, daylight can cause visual discomfort in the form of glare. Center of Art, Design, and Language (CADL Institut Teknologi Bandung is a building that has windows on west and east facades, so the probability of glare occurrence is high. In this research, CADL was optimized so that the percentage of time that Daylight Glare Probability below 0.21 (%DGP<0.21 is more than 50% and spatial daylight autonomy with illuminance 150 lux and 50% (sDA150lux,50% is more than 30%. In the optimization, vertical blinds, horizontal blinds, and curtains were added. Vertical blinds and horizontal blinds were varied by changing the blade’s opening angle and area covering the windows, while curtains were varied only by changing the area covering the windows. The results show that %DGP<0.21 can be increased beyond 50%, but in some rooms, sDA150,50% also decrease below 30%. The most frequent optimum solutions are vertical blinds 75%-60o.

  19. Practical approach to the use of daylight photodynamic therapy with topical methyl aminolevulinate for actinic keratosis

    DEFF Research Database (Denmark)

    Morton, C A; Wulf, H C; Szeimies, R M

    2015-01-01

    INTRODUCTION: Daylight-mediated photodynamic therapy has been shown to be an effective therapy for actinic keratoses (AKs) and a simple and tolerable treatment procedure in three randomized Scandinavian studies and two recent Phase III randomized controlled studies in Australia and Europe...

  20. A review of methods for the evaluation of the energy contribution of daylight in buildings

    Energy Technology Data Exchange (ETDEWEB)

    Attenborough, M; Goodwin, A

    1996-07-01

    A review has been undertaken of energy prediction methods and daylight calculation methods currently in use in the UK. This was based on a literature review and discussions with large engineering practices and academics involved in the areas of daylighting and energy simulation research. The aim of this review was to identify manual methods or computer programs that are capable of determining energy use in non-domestic buildings and of taking into account the energy savings resulting from daylighting. One potential application for these methods is in supporting anticipated energy targets for non-domestic buildings within Building Regulations and other energy labelling schemes. The review has identified a range of methods which are capable of predicting overall energy use while accounting for daylight. These vary in complexity from empirical methods such as ESICHECK and the CIBSE Energy Code through to dynamic energy simulation models such as DOE 2 and ESP. For each of the methods identified a brief assessment has been made of their technical capabilities ease of use and availability. These assessments have been based on discussions with users and program developers. Descriptions of the various methods are given. (Author)

  1. Effect of daylight saving time on lighting energy use: a literature review

    NARCIS (Netherlands)

    Aries, M.B.C.; Newsham, G.R.

    2008-01-01

    The principal reason for introducing (and extending) daylight saving time (DST) was, and still is, projected energy savings, particularly for electric lighting. This paper presents a literature review concerning the effects of DST on energy use. Simple estimates suggest a reduction in national

  2. Change in the Classroom Deportment of Children Following Change From Daylight Saving Time.

    Science.gov (United States)

    Hicks, Robert A.; And Others

    1980-01-01

    The deportment of each student in a third-grade classroom was rated by the teacher before and after the fall change from daylight savings time, to see if this disruption in circadian rhythms alters behavior. The deportment of boys improved significantly while the deportment of girls was significantly disrupted. (Author/SJL)

  3. Simple tool to evaluate the impact of daylight on building energy consumption

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Nielsen, Toke Rammer; Svendsen, Svend

    2008-01-01

    This paper presents a simple building simulation tool for integrated daylight and thermal analysis. The tool is capable of importing the thermal and visual properties for different glazings and shading positions from the Window Information System (WIS) program. A coupled ray-tracing and radiosity...

  4. Simple tool to evaluate the impact of daylight on building energy consumption

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Nielsen, Toke Rammer; Svendsen, Svend

    2008-01-01

    This paper presents a simple building simulation tool for integrated daylight and thermal analysis. The tool is capable of importing the thermal and visual properties for different glazings and shading positions from the Window Information System (WIS) program. Radiosity methodology is used...

  5. 75 FR 36089 - Payment System Risk Policy; Daylight Overdraft Posting Rules

    Science.gov (United States)

    2010-06-24

    ... FEDERAL RESERVE SYSTEM [OP-1385] Payment System Risk Policy; Daylight Overdraft Posting Rules... Payment System Risk Policy, the Board is announcing posting rules for a new same-day automated clearing... Kirkpatrick, Senior Financial Services Analyst, Payment System Risk (202-452-2796), or Jennifer Davidson...

  6. 77 FR 22666 - Payment System Risk Policy; Daylight Overdraft Posting Rules

    Science.gov (United States)

    2012-04-17

    ... FEDERAL RESERVE SYSTEM 12 CFR Part 204 [Docket No. OP-1440] Payment System Risk Policy; Daylight.... SUMMARY: The Board of Governors of the Federal Reserve System (Board) has revised its Policy on Payment...), Division of Reserve Bank Operations and Payment Systems. For users of Telecommunications Device for the...

  7. 78 FR 70046 - Payment System Risk Policy; Daylight Overdraft Posting Rules

    Science.gov (United States)

    2013-11-22

    ... FEDERAL RESERVE SYSTEM [Docket No. OP--1471] Payment System Risk Policy; Daylight Overdraft... Reserve Policy on Payment System Risk (PSR policy) to eliminate certain posting rules to conform with... Services Analyst (202- 452-2404), Division of Reserve Bank Operations and Payment Systems. For users of...

  8. Chromatic illumination discrimination ability reveals that human colour constancy is optimised for blue daylight illuminations.

    Directory of Open Access Journals (Sweden)

    Bradley Pearce

    Full Text Available The phenomenon of colour constancy in human visual perception keeps surface colours constant, despite changes in their reflected light due to changing illumination. Although colour constancy has evolved under a constrained subset of illuminations, it is unknown whether its underlying mechanisms, thought to involve multiple components from retina to cortex, are optimised for particular environmental variations. Here we demonstrate a new method for investigating colour constancy using illumination matching in real scenes which, unlike previous methods using surface matching and simulated scenes, allows testing of multiple, real illuminations. We use real scenes consisting of solid familiar or unfamiliar objects against uniform or variegated backgrounds and compare discrimination performance for typical illuminations from the daylight chromaticity locus (approximately blue-yellow and atypical spectra from an orthogonal locus (approximately red-green, at correlated colour temperature 6700 K, all produced in real time by a 10-channel LED illuminator. We find that discrimination of illumination changes is poorer along the daylight locus than the atypical locus, and is poorest particularly for bluer illumination changes, demonstrating conversely that surface colour constancy is best for blue daylight illuminations. Illumination discrimination is also enhanced, and therefore colour constancy diminished, for uniform backgrounds, irrespective of the object type. These results are not explained by statistical properties of the scene signal changes at the retinal level. We conclude that high-level mechanisms of colour constancy are biased for the blue daylight illuminations and variegated backgrounds to which the human visual system has typically been exposed.

  9. Application and Computer Analysis of Solar Systems for the Indoor Daylighting

    Energy Technology Data Exchange (ETDEWEB)

    Makhmudov, Is Kandar

    2010-02-15

    A steady increase of energy costs and ever growing environmental concerns in recent years have forced scientists to look for new methods of energy utilization. To resolve these dire problems, the application of renewable energy sources has been considered in various human activities in every sector of society. One of them is the development of solar daylighting systems for residential and commercial buildings, which can improve building energy efficiency and create comfortable indoor environment. Electric lighting represents up to 30 % of building electricity consumption. Therefore, using sunlight in indoor daylighting can significantly reduce electricity consumption in residential and commercial buildings. Moreover, daylight is an important factor in visual environment and improving human well-being. In last decades, different approaches to the design of solar daylighting systems have resulted in various innovative solutions to efficiently introduce natural light in buildings. But their efficiency and cost are still one of primary obstacles in the wider development and distribution of solar daylighting systems. In this study, we investigated the performance of a new solar concentrator system for indoor illumination. The solar concentrator system consists of 30 cm dish concentrators, high precision solar trackers, optical fibers and diffusers for a light distribution. In order to assess the daylighting system's efficiency, there were carried out several experimental measurement series. One of them was an application of our solar daylighting system to two standard classrooms with south- and north-oriented windows in Jeju city, Korea. At the same time classrooms were modeled by using ECOTECT and exported to RADIANCE for daylighting simulations. Results from the measurements and simulations were analyzed comprehensively to establish the reliability of the modeling process. Following this, we modeled both classrooms with the above mentioned daylighting systems

  10. Daylighting simulation : comparison of softwares for architect's utilization

    Energy Technology Data Exchange (ETDEWEB)

    Christakou, D.E.; Amorim, C.N.D. [Brazil Univ., Brasilia (Brazil). Faculty of Architecture and Urbanism

    2005-07-01

    This study analyzed and compared 4 daylighting software packages to determine the primary benefits and limits of each one, while considering the priorities for the use of the software by architects. The complex task of daylight simulation is an important step in designing buildings, particularly when the main objective is comfort and energy conservation. Simulation is not yet commonly practiced by professional architects because of the complexities of various software packages, the lack of user friendly interfaces and difficulty in interpreting results. The 4 software packages that were evaluated in this study were: (1) Desktop Radiance, (2) Rayfront, (3) Relux 2004 Vision, and (4) Lightscape. Criteria such as interfaces, flexibility, and help manuals were also analyzed in an effort to establish a frame of the main points to be considered when choosing daylighting software for architectural use, both in educational and office environments. Simulations of a test room were performed in which some parameters were modified to verify the performance of the following main criteria: flexibility in adapting to the architect's workflow; the use of state of the art algorithms; numerical precision; and, access possibility by Brazilian architects. The results demonstrate the potential of software's improvement, particular in terms of user interfaces and help manuals. The study showed that Relux 2004 Vision is the most adequate for architect's use. Rayfront and Desktop Radiance presented more difficulties in the design process, but Desktop Radiance had the advantage of being enclosed in AUTOCAD, a well known interface. Lightscape had a user friendly interface but was not as intuitive as Relux. It was concluded that the ideal daylighting simulation software does not yet exist. The ideal software should integrate diverse factors and combine edition and modeling tools beyond luminous evaluation and thermal consequences of daylight use. 5 refs., 3 tabs., 4 figs.

  11. Tuning the diurnal natural daylight with phosphor converted white LED – Advent of new phosphor blend composition

    International Nuclear Information System (INIS)

    Kim, Yoon Hwa; Arunkumar, Paulraj; Park, Seung Hyok; Yoon, Ho Shin; Im, Won Bin

    2015-01-01

    Highlights: • Designed phosphor blend that mimics diurnal daylight for health benefits. • Developed new phosphor blend composition that mimics natural sunlight under near UV. • The phosphor blend also exhibits high CRI (≥90) under blue LED excitation. • Fabricated WLED exhibited ∼91% spectral resemblance with daylight at 4500 K. • While ∼39.2% spectral resemblance were observed for YAG:Ce 3+ at 4500 K. - Abstract: We demonstrate the feasibility of developing phosphor converted white LED (pc-WLED) that mimics diurnal natural daylight with the newly designed phosphor blend in the color temperature (CCT) 2700–6000 K for health benefits. Natural daylight (sunlight) spectrum possesses broad emission in the visible region and closely approximates black body radiator, with color rendition index (CRI) of 100 under wide CCT (2500–6500 K). Current white light LEDs although are efficient and durable, they are not broad enough compared to daylight. We report new phosphor blend based on Sr 3 MgSi 2 O 8 :Eu 2+ blue phosphor with broad emission and high CRI ≥ 96 under both near UV and blue excitation. The fabricated WLED has exhibited ∼91% spectral resemblance with natural daylight compared to 39.2% for YAG:Ce 3+ white LED at 4500 K. The developed phosphor blend tunes the spectrum in wider CCT and would be a prospective candidate for full spectrum daylight WLED

  12. Tuning the diurnal natural daylight with phosphor converted white LED – Advent of new phosphor blend composition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoon Hwa [School of Materials Science and Engineering, Chonnam National University, 300, Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of); Research Institute, Force4 Corp., Daechon-dong, Buk-gu, Gwangju 500-470 (Korea, Republic of); Arunkumar, Paulraj [School of Materials Science and Engineering, Chonnam National University, 300, Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of); Park, Seung Hyok; Yoon, Ho Shin [Research Institute, Force4 Corp., Daechon-dong, Buk-gu, Gwangju 500-470 (Korea, Republic of); Im, Won Bin, E-mail: imwonbin@jnu.ac.kr [School of Materials Science and Engineering, Chonnam National University, 300, Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of)

    2015-03-15

    Highlights: • Designed phosphor blend that mimics diurnal daylight for health benefits. • Developed new phosphor blend composition that mimics natural sunlight under near UV. • The phosphor blend also exhibits high CRI (≥90) under blue LED excitation. • Fabricated WLED exhibited ∼91% spectral resemblance with daylight at 4500 K. • While ∼39.2% spectral resemblance were observed for YAG:Ce{sup 3+} at 4500 K. - Abstract: We demonstrate the feasibility of developing phosphor converted white LED (pc-WLED) that mimics diurnal natural daylight with the newly designed phosphor blend in the color temperature (CCT) 2700–6000 K for health benefits. Natural daylight (sunlight) spectrum possesses broad emission in the visible region and closely approximates black body radiator, with color rendition index (CRI) of 100 under wide CCT (2500–6500 K). Current white light LEDs although are efficient and durable, they are not broad enough compared to daylight. We report new phosphor blend based on Sr{sub 3}MgSi{sub 2}O{sub 8}:Eu{sup 2+} blue phosphor with broad emission and high CRI ≥ 96 under both near UV and blue excitation. The fabricated WLED has exhibited ∼91% spectral resemblance with natural daylight compared to 39.2% for YAG:Ce{sup 3+} white LED at 4500 K. The developed phosphor blend tunes the spectrum in wider CCT and would be a prospective candidate for full spectrum daylight WLED.

  13. External perforated Solar Screens for daylighting in residential desert buildings: Identification of minimum perforation percentages

    KAUST Repository

    Sherif, Ahmed

    2012-06-01

    The desert climate is endowed by clear sky conditions, providing an excellent opportunity for optimum utilization of natural light in daylighting building indoor spaces. However, the sunny conditions of the desert skies, in countries like Egypt and Saudi Arabia, result in the admittance of direct solar radiation, which leads to thermal discomfort and the incidence of undesired glare. One type of shading systems that is used to permit daylight while controlling solar penetration is " Solar Screens" Very little research work addressed different design aspects of external Solar Screens and their influence on daylighting performance, especially in desert conditions, although these screens proved their effectiveness in controlling solar radiation in traditional buildings throughout history.This paper reports on the outcomes of an investigation that studied the influence of perforation percentage of Solar Screens on daylighting performance in a typical residential living room of a building in a desert location. The objective was to identify minimum perforation percentage of screen openings that provides adequate illuminance levels in design-specific cases and all-year-round.Research work was divided into three stages. Stage one focused on the analysis of daylighting illuminance levels in specific dates and times, while the second stage was built on the results of the first stage, and addressed year round performance using Dynamic Daylight Performance Metrics (DDPMs). The third stage addressed the possibility of incidence of glare in specific cases where illuminance levels where found very high in some specific points during the analysis of first stage. The research examined the daylighting performance in an indoor space with a number of assumed fixed experimentation parameters that were chosen to represent the principal features of a typical residential living room located in a desert environment setting.Stage one experiments demonstrated that the screens fulfilled the

  14. Combined daylight and intelligent LED lighting - getting the daylight into the buildings; Kombineret dagslys og intelligent LED belysning - fae dagslys ind i bygningerne. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Dam-Hansen, C.; Corell, D.D.; Thorseth, A.; Behrensdorff Poulsen, P. [Technical Univ. of Denmark, DTU Fotonik, DTU Risoe Campus, Roskilde (Denmark); Markvart, J.; Iversen, A.; Logadottir, A. [Aalborg Univ., Statens Byggeforskningsinstitut (SBi), Koebenhavn (Denmark)

    2013-03-15

    The main result of the project is the construction of the new intelligent and dynamic LED lighting system for demonstration and research purposes, and a number of extensive user testing is completed. The LED lighting system is a total system for office lighting with ceiling fixtures and desk lamps, which has made it possible to create a general and workplace lighting in two offices each with two work places. The system is installed in a day light laboratory for such two office spaces. All lamps can be controlled via a developed computer interface, and the desk lamps are further manually controllable by a user via two buttons for color temperature and brightness, respectively. The new intelligent and dynamic lighting system is based on color mixing LED technology and makes it possible to control the color composition, color coordinates and thus the color temperature of the light. Control-wise, the system is pre-programmed to produce white light with a correlated color temperature from 2700 K to 7000 K. The color composition is optimized from the desire for a very good color given at a general CRI value of 92-97 over the area. The system can be dimmed 20-100 %, with no significant change in the light's color properties. A mini-spectrometer is calibrated and built-in in the system and provides the current estimate of daylight brightness and color temperature through measurement of daylight color scheme in the visible range. The system uses daylight properties to control the light from the LED lighting system. The results of user tests show, that the developed possibility to automatically control of light in the office depending on the daylight color temperature is considered to be equally preferred and results in equally satisfied users as a traditional lighting system with even lighting in the room. On the other hand, user results showed that there were both energy savings and more satisfied users to be gained by providing users the opportunity to self-adjust either

  15. Energy-efficient window systems. Effects on energy use and daylight in buildings

    Energy Technology Data Exchange (ETDEWEB)

    Buelow-Huebe, H.

    2001-11-01

    This thesis deals with energy-efficient windows in Swedish buildings. Parametric studies were performed in the dynamic energy simulation tool Derob-LTH in order to study the effects of window choices on energy use and indoor climate for both residential and office buildings. A steady-state program was used to evaluate two years of measurements of energy use and indoor temperatures of an energy-efficient row-house. Two behavioural studies regarding (1) daylight transmittance, view and room perception using super-insulated windows and (2) the satisfaction with the daylight environment and the use of shading devices in response to daylight/sunlight were conducted in full-scale laboratory environments exposed to the natural climate. Results show that as the energy-efficiency of buildings increase, window U-values must decrease in order not to increase the annual heating demand, since the heating season is shortened, and useful solar gains become smaller. For single-family houses with a window-to-floor area ratio of 15 % and insulated according the current Swedish building code, the U-values should thus on average be lower than 1.0 W/m{sup 2}K. For houses insulated according to 1960s standard, the U-value may on average be 1.6 W/m{sup 2}K. For colder climates (northern Sweden), the U-values should be somewhat lower, while slightly higher U-values can be tolerated in milder climates of south Sweden. Thermal comfort during winter is improved for energy-efficient windows. However, overheating problems exist for both super-insulated houses and highly glazed office buildings showing a need for very low U-values in combination with low g-values. Daylight experiments indicate that the use of two low-emittance coatings tints the transmitted daylight enough to be appreciated, and colours may be perceived as more drab and rooms more enclosed. A compromise between energy-efficiency and daylighting may be needed, and it is suggested that only one coating be used except when very

  16. Effects of daylight-saving time changes on stock market volatility: a comment.

    Science.gov (United States)

    Kamstra, Mark J; Kramer, Lisa A; Levi, Maurice D

    2010-12-01

    In a recent article in this journal, Berument, Dogan, and Onar (2010) challenged the existence of the previously documented daylight-saving effect. Kamstra, Kramer, and Levi's original finding (2000) was that average stock market returns on Mondays following time changes are economically and statistically significantly lower than typical Monday returns. Kamstra, et al. hypothesized that the effect may arise due to heightened anxiety or risk aversion on the part of market participants after they experience a 1-hr. disruption in their sleep habits, in accordance with prior findings in the psychology literature linking sleep desynchronosis with anxiety. Berument, et al. replicated the original findings using ordinary least squares estimation, but when they modeled the mean of returns using a method prone to producing biased estimates, they obtained puzzling results. The analysis here, based on standard, unbiased modeling techniques, shows that the daylight-saving effect remains intact in the U.S.

  17. Mathematical model quantifies multiple daylight exposure and burial events for rock surfaces using luminescence dating

    DEFF Research Database (Denmark)

    Freiesleben, Trine Holm; Sohbati, Reza; Murray, Andrew

    2015-01-01

    Interest in the optically stimulated luminescence (OSL) dating of rock surfaces has increased significantly over the last few years, as the potential of the method has been explored. It has been realized that luminescence-depth profiles show qualitative evidence for multiple daylight exposure...... and burial events. To quantify both burial and exposure events a new mathematical model is developed by expanding the existing models of evolution of luminescenceedepth profiles, to include repeated sequential events of burial and exposure to daylight. This new model is applied to an infrared stimulated...... events. This study confirms the suggestion that rock surfaces contain a record of exposure and burial history, and that these events can be quantified. The burial age of rock surfaces can thus be dated with confidence, based on a knowledge of their pre-burial light exposure; it may also be possible...

  18. Computer Modeling of Daylight-Integrated Photocontrol of Electric Lighting Systems

    Directory of Open Access Journals (Sweden)

    Richard Mistrick

    2015-05-01

    Full Text Available This article presents a variety of different approaches to both model and assess the performance of daylight-integrated electric lighting control systems. In these systems, the output of a controlled lighting zone is based on a light sensor reading and a calibrated control algorithm. Computer simulations can consider the simulated illuminance data generated from both the electric lighting system and a daylight delivery system whose performance is addressed using typical meteorological year (TMY weather data. Photosensor signals and the operation of a control system’s dimming algorithms are also included. Methods and metrics for evaluating simulated performance for the purpose of making informed design decisions that lead to the best possible installed system performance are presented.

  19. The impact of changing solar screen rotation angle and its opening aspect ratios on Daylight Availability in residential desert buildings

    KAUST Repository

    Sherif, Ahmed H.; Sabry, Hanan M.; Gadelhak, Mahmoud I.

    2012-01-01

    usually used to diffuse and prevent direct solar penetration into spaces. This paper investigates the impact of changing solar screen axial rotation angle and screen opening aspect ratio on daylighting performance in a typical residential living room space

  20. Daylight Management in Mediterranean Cities: When Shortage Is Not the Issue

    OpenAIRE

    Judit Lopez-Besora; Glòria Serra-Coch; Helena Coch; Antonio Isalgue

    2016-01-01

    Natural resources such as daylight and sunlight are highly appreciated in countries with prevailing overcast skies. Taking advantage of this scarce resource contributes to saving energy on artificial lighting. In contrast to northern, southern European cities are distinguished by a large number of days with direct sunlight caused by a propitious climate condition. While it is a positive issue in terms of energy availability, the abundance of it can be counterproductive if management measures ...

  1. Mathematical model quantifies multiple daylight exposure and burial events for rock surfaces using luminescence dating

    International Nuclear Information System (INIS)

    Freiesleben, Trine; Sohbati, Reza; Murray, Andrew; Jain, Mayank; Al Khasawneh, Sahar; Hvidt, Søren; Jakobsen, Bo

    2015-01-01

    Interest in the optically stimulated luminescence (OSL) dating of rock surfaces has increased significantly over the last few years, as the potential of the method has been explored. It has been realized that luminescence-depth profiles show qualitative evidence for multiple daylight exposure and burial events. To quantify both burial and exposure events a new mathematical model is developed by expanding the existing models of evolution of luminescence–depth profiles, to include repeated sequential events of burial and exposure to daylight. This new model is applied to an infrared stimulated luminescence-depth profile from a feldspar-rich granite cobble from an archaeological site near Aarhus, Denmark. This profile shows qualitative evidence for multiple daylight exposure and burial events; these are quantified using the model developed here. By determining the burial ages from the surface layer of the cobble and by fitting the new model to the luminescence profile, it is concluded that the cobble was well bleached before burial. This indicates that the OSL burial age is likely to be reliable. In addition, a recent known exposure event provides an approximate calibration for older daylight exposure events. This study confirms the suggestion that rock surfaces contain a record of exposure and burial history, and that these events can be quantified. The burial age of rock surfaces can thus be dated with confidence, based on a knowledge of their pre-burial light exposure; it may also be possible to determine the length of a fossil exposure, using a known natural light exposure as calibration. - Highlights: • Evidence for multiple exposure and burial events in the history of a single cobble. • OSL rock surface dating model improved to include multiple burial/exposure cycles. • Application of the new model quantifies burial and exposure events.

  2. How daylight influences high-order chromatic descriptors in natural images.

    Science.gov (United States)

    Ojeda, Juan; Nieves, Juan Luis; Romero, Javier

    2017-07-01

    Despite the global and local daylight changes naturally occurring in natural scenes, the human visual system usually adapts quite well to those changes, developing a stable color perception. Nevertheless, the influence of daylight in modeling natural image statistics is not fully understood and has received little attention. The aim of this work was to analyze the influence of daylight changes in different high-order chromatic descriptors (i.e., color volume, color gamut, and number of discernible colors) derived from 350 color images, which were rendered under 108 natural illuminants with Correlated Color Temperatures (CCT) from 2735 to 25,889 K. Results suggest that chromatic and luminance information is almost constant and does not depend on the CCT of the illuminant for values above 14,000 K. Nevertheless, differences between the red-green and blue-yellow image components were found below that CCT, with most of the statistical descriptors analyzed showing local extremes in the range 2950 K-6300 K. Uniform regions and areas of the images attracting observers' attention were also considered in this analysis and were characterized by their patchiness index and their saliency maps. Meanwhile, the results of the patchiness index do not show a clear dependence on CCT, and it is remarkable that a significant reduction in the number of discernible colors (58% on average) was found when the images were masked with their corresponding saliency maps. Our results suggest that chromatic diversity, as defined in terms of the discernible colors, can be strongly reduced when an observer scans a natural scene. These findings support the idea that a reduction in the number of discernible colors will guide visual saliency and attention. Whatever the modeling is mediating the neural representation of natural images, natural image statistics, it is clear that natural image statistics should take into account those local maxima and minima depending on the daylight illumination and

  3. Technology Assessments of High Performance Envelope with Optimized Lighting, Solar Control, and Daylighting

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eleanor S.; Thanachareonkit, Anothai; Touzani, Samir; Dutton, Spencer; Shackelford, Jordan; Dickerhoff, Darryl; Selkowitz, Stephen

    2016-09-01

    The objective of this monitored field study was to identify near-term innovative façade technologies for solar control and daylighting with a goal of 20-40% energy use savings below Title 24 2013 in the 30-ft deep perimeter zone near vertical windows within cost and comfort constraints. The targeted market was new or existing commercial office buildings or buildings with similar patterns of use.

  4. Using the Life Satisfaction Approach to Value Daylight Savings Time Transitions: Evidence from Britain and Germany

    OpenAIRE

    Daniel Kuehnle; Christoph Wunder

    2015-01-01

    Daylight savings time (DST) represents a public good with costs and benefits. We provide the first comprehensive examination of the welfare effects of the spring and autumn transitions for the UK and Germany. Using individual-level data and a regression discontinuity design, we estimate the effect of the transitions on life satisfaction. Our results show that individuals in both the UK and Germany experience deteriorations in life satisfaction in the first week after the spring transition. We...

  5. Daylight Savings Time Transitions and the Incidence Rate of Unipolar Depressive Episodes.

    Science.gov (United States)

    Hansen, Bertel T; Sønderskov, Kim M; Hageman, Ida; Dinesen, Peter T; Østergaard, Søren D

    2017-05-01

    Daylight savings time transitions affect approximately 1.6 billion people worldwide. Prior studies have documented associations between daylight savings time transitions and adverse health outcomes, but it remains unknown whether they also cause an increase in the incidence rate of depressive episodes. This seems likely because daylight savings time transitions affect circadian rhythms, which are implicated in the etiology of depressive disorder. Therefore, we investigated the effects of daylight savings time transitions on the incidence rate of unipolar depressive episodes. Using time series intervention analysis of nationwide data from the Danish Psychiatric Central Research Register from 1995 to 2012, we compared the observed trend in the incidence rate of hospital contacts for unipolar depressive episodes after the transitions to and from summer time to the predicted trend in the incidence rate. The analyses were based on 185,419 hospital contacts for unipolar depression and showed that the transition from summer time to standard time were associated with an 11% increase (95% CI = 7%, 15%) in the incidence rate of unipolar depressive episodes that dissipated over approximately 10 weeks. The transition from standard time to summer time was not associated with a parallel change in the incidence rate of unipolar depressive episodes. This study shows that the transition from summer time to standard time was associated with an increase in the incidence rate of unipolar depressive episodes. Distress associated with the sudden advancement of sunset, marking the coming of a long period of short days, may explain this finding. See video abstract at, http://links.lww.com/EDE/B179.

  6. Apolux : an innovative computer code for daylight design and analysis in architecture and urbanism

    Energy Technology Data Exchange (ETDEWEB)

    Claro, A.; Pereira, F.O.R.; Ledo, R.Z. [Santa Catarina Federal Univ., Florianopolis, SC (Brazil)

    2005-07-01

    The main capabilities of a new computer program for calculating and analyzing daylighting in architectural space were discussed. Apolux 1.0 was designed to use three-dimensional files generated in graphic editors in the data exchange file (DXF) format and was developed to integrate an architect's design characteristics. An example of its use in a design context development was presented. The program offers fast and flexible manipulation of video card models in different visualization conditions. The algorithm for working with the physics of light is based on the radiosity method representing the surfaces through finite elements divided in small triangular units of area which are fully confronted to each other. The form factors of each triangle are determined in relation to all others in the primary calculation. Visible directions of the sky are also included according to the modular units of a subdivided globe. Following these primary calculations, the different and successive daylighting solutions can be determined under different sky conditions. The program can also change the properties of the materials to quickly recalculate the solutions. The program has been applied in an office building in Florianopolis, Brazil. The four stages of design include initial discussion with the architects about the conceptual possibilities; development of a comparative study based on 2 architectural designs with different conceptual elements regarding daylighting exploitation in order to compare internal daylighting levels and distribution of the 2 options exposed to the same external conditions; study the solar shading devices for specific facades; and, simulations to test the performance of different designs. The program has proven to be very flexible with reliable results. It has the possibility of incorporating situations of the real sky through the input of the Spherical model of real sky luminance values. 3 refs., 14 figs.

  7. Effects of daylight-saving time changes on stock market returns and stock market volatility: rebuttal.

    Science.gov (United States)

    Kamstra, Mark J; Kramer, Lisa A; Levi, Maurice D

    2013-02-01

    In a 2011 reply to our 2010 comment in this journal, Berument and Dogen maintained their challenge to the existence of the negative daylight-saving effect in stock returns reported by Kamstra, Kramer, and Levi in 2000. Unfortunately, in their reply, Berument and Dogen ignored all of the points raised in the comment, failing even to cite the Kamstra, et al. comment. Berument and Dogen continued to use inappropriate estimation techniques, over-parameterized models, and low-power tests and perhaps most surprisingly even failed to replicate results they themselves reported in their previous paper, written by Berument, Dogen, and Onar in 2010. The findings reported by Berument and Dogen, as well as by Berument, Dogen, and Onar, are neither well-supported nor well-reasoned. We maintain our original objections to their analysis, highlight new serious empirical and theoretical problems, and emphasize that there remains statistically significant evidence of an economically large negative daylight-saving effect in U.S. stock returns. The issues raised in this rebuttal extend beyond the daylight-saving effect itself, touching on methodological points that arise more generally when deciding how to model financial returns data.

  8. Daylight Design of Office Buildings: Optimisation of External Solar Shadings by Using Combined Simulation Methods

    Directory of Open Access Journals (Sweden)

    Javier González

    2015-05-01

    Full Text Available Integrating daylight and energy performance with optimization into the design process has always been a challenge for designers. Most of the building environmental performance simulation tools require a considerable amount of time and iterations for achieving accurate results. Moreover the combination of daylight and energy performances has always been an issue, as different software packages are needed to perform detailed calculations. A simplified method to overcome both issues using recent advances in software integration is explored here. As a case study; the optimization of external shadings in a typical office space in Australia is presented. Results are compared against common solutions adopted as industry standard practices. Visual comfort and energy efficiency are analysed in an integrated approach. The DIVA (Design, Iterate, Validate and Adapt plug-in for Rhinoceros/Grasshopper software is used as the main tool, given its ability to effectively calculate daylight metrics (using the Radiance/Daysim engine and energy consumption (using the EnergyPlus engine. The optimization process is carried out parametrically controlling the shadings’ geometries. Genetic Algorithms (GA embedded in the evolutionary solver Galapagos are adopted in order to achieve close to optimum results by controlling iteration parameters. The optimized result, in comparison with conventional design techniques, reveals significant enhancement of comfort levels and energy efficiency. Benefits and drawbacks of the proposed strategy are then discussed.

  9. Transition into daylight saving time influences the fragmentation of the rest-activity cycle

    Directory of Open Access Journals (Sweden)

    Tuulio-Henriksson Annamari

    2006-01-01

    Full Text Available Abstract Background Daylight saving time is widely adopted. Little is known about its influence on the daily rest-activity cycles. We decided to explore the effects of transition into daylight saving time on the circadian rhythm of activity. Methods We monitored the rest-activity cycles with the use of wrist-worn accelerometer on a sample of ten healthy adults for ten days around the transition into summer time. Identical protocols were carried out on the same individuals in two consecutive years, yielding data on 200 person-days for analysis in this study. Results There was no significant effect on the rest-activity cycle in the sample as a whole. Fragmentation of the rest-activity cycle was enhanced in a subgroup of persons having sleep for eight hours or less (P = 0.04 but reduced in those who preferred to sleep for more than eight hours per night (P = 0.05. The average level of motor activity was increased in persons having the morning preference for daily activity patterns (P = 0.01. Conclusion Transition into daylight saving time may have a disruptive effect on the rest-activity cycle in those healthy adults who are short-sleepers or more of the evening type.

  10. Making daylighting work. Learning from failures to improve the design and implementation process

    Energy Technology Data Exchange (ETDEWEB)

    Vaidya, Prasad; McDougall, Tom; Steinbock, Jason; Douglas, James; Eijadi, David [The Weidt Group, Berkeley, CA (United States)

    2005-07-01

    Daylighting, hailed as a cornerstone of sustainable building design, is the primary passive solar design strategy in commercial buildings. It has the potential to significantly reduce lighting energy, which can be 40% or more of the energy cost of a commercial building. We have found that projects with daylighting often do not provide the expected energy savings. In a risk-averse construction industry, even limited failures can dramatically slow the advance of valid technologies. There are numerous reasons for failure: natural light sources are complex and vary through the day and year; implementation requires coordination between different building design and construction trades; the documentation and specification of the controls equipment is often inadequate; and calibration after installation is rarely done well and can be confusing and time consuming. In this paper, we provide four case studies as representative examples where daylighting did not deliver the expected energy savings. We identify the primary modes of failure and provide a template for each mode for easier problem resolution in the future. Through a detailed analysis of the case studies, we identify problem areas in the design and implementation process; we propose a more generalized solution set for design steps, documentation requirements and implementation checks that increase the chances of success.

  11. The shift to and from daylight savings time and motor vehicle crashes.

    Science.gov (United States)

    Lambe, M; Cummings, P

    2000-07-01

    The objective of the study was to examine whether the shifts to and from daylight savings time in Sweden have short-term effects on the incidence of traffic crashes. A database maintained by the Swedish National Road Administration was used to examine crashes from 1984 through 1995, that occurred on state roads the Monday preceding, the Monday immediately after (index Monday), and the Monday 1 week after the change to daylight savings time in the spring and for the corresponding three Mondays in the autumn. The Mondays 1 week before and after the time changes were taken as representing the expected incidence of crashes. Crash incidence was calculated per 1000 person-years using population estimates for each year of the study. The association between 1 h of possible sleep loss and crash incidence was estimated by the incidence rate ratio from negative binomial regression. The incidence rate ratio was 1.04 (95% CI, 0.92-1.16) for a Monday on which drivers were expected to have had 1 h less sleep, compared with other Mondays. In the spring, the incidence rate ratio for crashes was 1.11 (95% CI, 0.93-1.31) for Mondays after the time change compared to other spring Mondays. The corresponding rate ratio for the fall was 0.98 (95% CI, 0.84-1.15) It was concluded that the shift to and from daylight savings time did not have measurable important immediate effects on crash incidence in Sweden.

  12. Daylighting and energy performance of a building for composite climate: An experimental study

    Directory of Open Access Journals (Sweden)

    Madhu Sudan

    2016-12-01

    Full Text Available The present study includes overall energy saving through thermal as well as daylighting for composite climate for the building known as SODHA BERS COMPLEX (SBC situated at Varanasi, India. The building has been designed including all the passive concepts for thermal comfort as well daylighting to maximize the use of natural lighting for the occupants in day to day activities. This approach can be useful for multi-story building for rural and urban areas for both residential and commercial buildings. The energy saving potential and corresponding CO2 mitigation have been determined for different lifetimes of the building. The energy matrices namely energy payback time (EPBT, energy production factor (EPF and life cycle conversion efficiency (LCCE of the building have also been estimated by considering overall energy saving. An annual energy saving has been obtained as 3675.61 kW h due to daylight concept by considering different Zones in each floors of the building. Further, the EPBT has been determined as 49.25 years and 34.73 years for average 4 °C and 6 °C temperature difference between ambient and room, respectively. It has been found that when thermal heat gain increases in the building LCCE and EPF increase.

  13. The role of fenestration in promoting daylight performance. The mosques of Alexandria since the 19th century

    Directory of Open Access Journals (Sweden)

    Ingy I. El-Darwish

    2016-12-01

    Full Text Available Mosques have always been sacred places with distinctive sustainable environments. Fenestration in the prayers’ zone whether clerestories, screened windows, dome lighting and other light features have managed to produce significant spiritual human comfort areas. This paper focuses on fenestration of divine mosques and relates them to promoting daylight performance. The research process emphasizes the importance of daylight performance by promoting simulation tools on historical mosques of Alexandria since the 19th century that has witnessed change over time. The paper is a step toward sustainable lighting schemes in prayers’ zones that help to achieve human comfort as well as minimize use of energy. This study aimed at investigating the daylight performance by the use of climate based daylighting metrics which is “Daylight Autonomy” (DA. Daylight Autonomy is evaluated in the year round for the day lighted prayer periods to evaluate the behavior of fenestration of the different selected sample of mosques since the 19th century in Alexandria on a simulation tool in order to check whether it complies with the required illuminate and glare levels. The research findings are an attempt to lead to performative design guidelines introducing a contemporary interpretation for use in enhancing new designs of these holistic buildings.

  14. Use of Daylight and Aesthetic Image of Glass Facades in Contemporary Buildings

    Science.gov (United States)

    Roginska-Niesluchowska, Malgorzata

    2017-10-01

    The paper deals with the architecture of contemporary buildings in respect to their aesthetic image created by the use of natural light. Sustainability is regarded as a governing principle of contemporary architecture, where daylighting is an important factor as it affects energy consumption and environmental quality of the space inside a building. Environmental awareness of architecture, however, involves a much wider and more holistic view of design. The quality of sustainable architecture can be considered in its aesthetic and cultural context with regard to landscape, local tradition, and connection to the surrounding world. This approach is associated with the social mission of architecture, i.e. providing appropriate space for living, facilitating social relations and having positive impact on people. The purpose of the research is to study the use of daylight in creating an aesthetic image of contemporary buildings. The author focuses mainly on public buildings largely dedicated to art and culture which satisfy high functional and aesthetic requirements. The paper examines the genesis and current trends in the aesthetic image of modern buildings which use daylight as the main design strategy, focusing on the issues of glass facades. The main attention is given to the shaping of representative public areas which feature the glass facades. The research has been based on a case study, critical review of literature review, observation and synthesis. The study identifies and classifies different approaches to using daylight in these areas and highlights changes in the aesthetics of architecture made of glass, which uses daylight as the main design strategy. These changes are primarily caused by the development and spreading of new glazing materials and the use of digital method of design. The influence of light and its mode depends on glass materials but also on the local conditions of the site, and has a significant impact on the relationship between

  15. Optimal sun-shading design for enhanced daylight illumination of subtropical classrooms

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Ming-Chin [Architecture and Building Research Institute, MOI (China); Chiang, Che-Ming [Department of Architecture, National Cheng-Kung University, Tainan 701 (China); Chou, Po-Cheng [Department of Interior Design, Shu-Te University, No. 59 Hun-Shan Road, Yenchau 82445, Kaohsiung County (China); Chang, Kuei-Feng [Department of Real Estate Management, National Pingtung Institute of Commerce (China); Lee, Chia-Yen [Department of Mechanical and Automation Engineering, Da-Yeh University, Changhua 515 (China)

    2008-07-01

    This study investigates the feasibility of fitting windows with sun-shadings in order to minimize the lighting power costs in daylight-illuminated classrooms lit from a single side in subtropical regions. An IES-CPC model is created of a representative classroom in Taiwan, and a series of simulations is performed to determine the average illuminance value and the uniformity of the illuminance distribution in the classroom under various lighting conditions with no sun-shadings fitted to the window. The numerical results are found to be in good agreement with the experimental measurements obtained using an array of nine-channel photometers. Having confirmed the validity of the simulation scheme, the illumination properties of four different sun-shading designs are considered. The results show that a double-layered sun-shading represents the optimal sun-shading design in terms of achieving a uniform illumination distribution within the classroom. Given appropriate physical dimensions, this daylight access device achieves the minimum illuminance requirement of 500 lx and improves the lighting uniformity ratio from 0.25-0.35 to 0.40-0.42. Furthermore, using this sun-shading device, the required illuminance ratio of 0.5 can be obtained simply by switching on one of the three rows of lights in the classroom. Accordingly, the daylight access device not only improves the illuminance conditions within the classroom, but also reduces the lighting power cost by 71.5% compared to the case where all of the lights are turned on. (author)

  16. Daylight Utilization with Light Pipe in Farm Animal Production: A Simulation Approach

    Directory of Open Access Journals (Sweden)

    Alejandro Pacheco Diéguez’

    2016-06-01

    Full Text Available Light pipes offer a passive way to bring daylight inside deep buildings, such as agricultural buildings. However, the lack of reliable performance predictability methods for light pipes represents a major obstacle preventing their widespread use. This paper evaluates a simulation approach for performance prediction and identifies key light pipe design parameters affecting their daylight transmission performance. The study was carried out through continuous monitoring of daylight in two full-scale, identical pig stables fitted with two light pipe systems, Solatube® and Velux®. The experiment included three continuously measuring sensors in each stable and an outdoor sensor during 2013 and 2014. A forward raytracing tool, TracePro®, was used for illuminance prediction and parametric simulations. The simulation results for overcast skies indicated discrepancies between the simulated and average measurement results below 30% in all cases. The discrepancies for clear skies were somewhat higher, i.e., below 30% for 67% of the cases. The higher discrepancies with clear skies were due to the overestimation of absolute sunlight levels and absence of an advanced and detailed optical characterization of the dome collector’s surface. The parametric results have shown that light pipes’ performance is better during summer time, in sunny climates, at low to mid-latitudes, which provides higher solar altitudes than during winter and cloudy climates at high latitudes. Methods to improve the luminous transmittance for low solar altitudes occurring in Scandinavia include: bending or tilting the pipe, increasing the aspect ratio, improving the pipe specular reflectance, tilting the collector to the south, and using optical redirecting system in the collector.

  17. The influence of the lateral distances between buildings on the availability of indoor daylighting

    Directory of Open Access Journals (Sweden)

    Andrea Coelho Laranja

    2014-12-01

    Full Text Available This study addresses aspects related to daylighting in the indoor environment, more specifically the influence of lateral distances between obstructing buildings on the availability of indoor daylighting, taking the height of the buildings and width of the roads into account. In accordance with the adopted methodology, comparisons were made of the percentage of illuminance values of the internal environment by using UDI (Useful Daylight Illuminance ranges on a selected point within an interior environment with an opening oriented to the North. The percentages of illuminance values were generated by simulation using the TropLux program in a rectangular geometry environment inserted in an urban setting in the city of Vitória, Espírito Santo (Latitude 20°19'S. The simulations were carried out for three types of sky patterns recognized by the CIE (Commission Internationale L'aclairage. One of the main results of this study was that, in locations with sky types 3 (overcast, 7 (partly cloudy, and 12 (clear, there were greater variations in the average annual internal illuminance when there were changes in the lateral distances between the obstructing buildings that were not directly in front of the building that was being analyzed. It was also found that in area with sky types 3 (overcast, 7 (partly cloudy, and 12 (clear, changes in the lateral distances between the three obstructing buildings had little effect on percentage changes in the 100≤UDI≤500 lux range and 500≤UDI ≤2000 lux range.

  18. Impact of solar shading on daylight quality. Measurements in experimental office rooms

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, M.C.

    2001-07-01

    The impact of ten solar shading screens and one venetian blind on daylight quality was studied through measurements in two south-oriented experimental office rooms. The daylight quality was assessed by considering five performance indicators: the daylight factor, the work plane illuminance, the illuminance uniformity on the work plane, the absolute luminance in the field of view and the luminance ratios between the paper task, the walls and the VDT screen. The measurements were carried out under perfect sunny conditions and overcast conditions. The results show that the shading devices can be divided into three distinct groups. Group 1 consists of all dark-coloured screens; Group 2 includes the closed venetian blind while Group 3 includes the white screens and the horizontal venetian blind. The devices of Group 1 produced unacceptably low work plane illuminance and vertical luminance values which resulted in unsuitable luminance ratios between the task, the walls and VDT screen. However, these devices reduced the luminance of the window (sky) to acceptable levels. The devices of Group 3 did not prevent high window luminance but yielded higher levels of work plane illuminance and inner wall luminance, which makes them suitable for traditional paper tasks. They also generated high wall luminance values which resulted in a number of unacceptable luminance ratios between the task, walls and VDT screen. The closed venetian blind (Group 2) was the only device which scored well on all performance indicators considered. It provided ideal illuminance levels for paper and VDT tasks and resulted in favourable wall luminance values for computer work.

  19. Critical analysis of the daylight saving time; Analisis critico al horario del verano

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes Rubio, Hernando [Universidad Autonoma Metropolitana Ciudad-Ixtapalapa, Mexico, D.F., (Mexico)

    2001-07-01

    The critical analysis is presented as a synthesis of the problem untied since the implementation of the daylight saving time. The often related history is retaken to introduce the reader into the context of the causes of a such program. The geometric aspect of the solar trajectories is discussed and the length of the day as a function of the latitude and the time of the year to have technical elements for the time displacement in a certain region. The technical implementation of the daylight saving time based on three elements is justified: time of dawn and the decline (length of the day), national economic motivation and tourism industry. Stands out that although the daylight saving time schedule has a set of social and economic benefits it is not centered in the individual but in the society as a whole. The errors in handling the information and the misinformation are pointed out as the main causes of the controversy, the discord and the political manipulation of competing groups. [Spanish] El analisis critico se presenta como una sintesis del problema desatado desde la implementacion del horario de verano. La historia muchas veces contada se retoma para introducir al lector en el contexto de las causas de un tal programa. Se discute el aspecto geometrico de las trayectorias solares y la longitud del dia como una funcion de la latitud y de la epoca del ano para tener elementos tecnicos para el desplazamiento horario en una region determinada. Se justifica la implementacion tecnica del horario de verano en funcion de tres elementos: hora de alba y del ocaso (longitud del dia), motivacion economica nacional e industria turistica. Se destaca que si bien el horario de verano tiene un conjunto de beneficios sociales y economicos no se centra en el individuo sino en la sociedad en su conjunto. Se senalan los errores de manejo de la informacion y la desinformacion como los principales causantes de la polemica, el desacuerdo y la manipulacion politica de grupos

  20. Overheating and Daylighting; Assessment Tool in Early Design of London’s High-Rise Residential Buildings

    Directory of Open Access Journals (Sweden)

    Bachir Nebia

    2017-08-01

    Full Text Available High-rise residential buildings in dense cities, such as London, are a common response to housing shortage. The apartments in these buildings may experience different levels of thermal and visual comfort, depending on their orientation and floor level. This paper aims to develop simplified tools to predict internal temperatures and daylighting levels, and propose a tool to quickly assess overheating risk and daylight performance in London’s high-rise residential buildings. Single- and double-sided apartments in a high-rise building were compared, and the impact of their floor level, glazing ratio, thermal mass, ventilation strategy and orientation was investigated. Using Integrated Environmental Solutions Virtual Environment (IES VE, temperature and daylight factor results of each design variable were used to develop early design tools to predict and assess overheating risks and daylighting levels. The results indicate that apartments that are more exposed to solar radiations, through either orientation or floor level, are more susceptible to overheat in the summer while exceeding the daylighting recommendations. Different design strategies at different levels and orientations are subsequently discussed.

  1. Analysing the impact of reflectance distributions and well geometries on vertical surface daylight levels in atria for overcast skies

    Energy Technology Data Exchange (ETDEWEB)

    Du, Jiangtao; Sharples, Steve [School of Architecture, University of Sheffield, Crookesmoor Building, Conduit Road, Sheffield S10 1FL (United Kingdom)

    2010-07-15

    This study investigated the impacts of different diffuse reflectance distributions and well geometries on vertical daylight factors and vertical internally reflected components in atria. Two forms of reflectance distribution patterns of wall surface were examined: horizontal and vertical reflectance band variation. The square atrium models studied have a broader WI range of 0.25-2.0, which represent shallow, medium and high atria. Radiance, a powerful package based on backward ray tracing technique, was used for the simulations of vertical daylight levels. The results show that different reflectance distributions of square atrium walls do have an impact on the vertical daylight factors and vertical internally reflected components under overcast sky condition. The impact relates to the orientation of the band with different reflectance distributions on the wall. Compared with the vertical band surface, the horizontal band surface has a much more complicated effect. The horizontal distributions of the reflectances significantly affects the vertical daylight levels at the locations more than 30% atrium height on the wall. For an atrium with a height more than 1/2 the width, the effect tends to increase with the increasing well index. The vertical distributions of the reflectance, nevertheless, do not substantially take effect on the vertical daylight levels in atria except for some special reflectance distribution patterns. (author)

  2. Daylight Influence on Colour Design : Empirical Study on Perceived Colour and Colour Experience Indoors

    OpenAIRE

    Hårleman, Maud

    2007-01-01

    It is known that one and the same interior colouring will appear different in rooms with windows facing north or facing south, but it is not known how natural daylight from these two compass points affects perceived colour and the ways in which colour is experienced. The objective is to describe the perceived colours to be expected in rooms with sunlight and diffused light, and thus develop a tool for colour design. Two empirical investigations provide the basis for six attached papers. The m...

  3. Effects of Daylight Saving Time changes on stock market volatility: a reply.

    Science.gov (United States)

    Berument, Hakan; Dogan, Nukhet

    2011-12-01

    There is a rich array of evidence that suggests that changes in sleeping patterns affect an individual's decision-making processes. A nationwide sleeping-pattern change happens twice a year when the Daylight Saving Time (DST) change occurs. Kamstra, Kramer, and Levi argued in 2000 that a DST change lowers stock market returns. This study presents evidence that DST changes affect the relationship between stock market return and volatility. Empirical evidence suggests that the positive relationship between return and volatility becomes negative on the Mondays following DST changes.

  4. Effect of short-term simulated daylight exposure on optically brightened papers

    International Nuclear Information System (INIS)

    Green, Phil; Honess, Mike

    2010-01-01

    Two optically brightened commercial papers were subjected to 72 hours continuous exposure to graphic arts daylight simulating fluorescent lamps at 1.4 and 4.4 klux. At the higher illuminance level, a CIELAB colour difference of 1.0 was reached in approximately 3 and 50 hours for the two papers. The colour differences produced by the 1.4 klux exposure were greater than that predicted by assuming a linear relationship between intensity and colour change, by a factor of 1.8.

  5. Development of a new model to predict indoor daylighting: Integration in CODYRUN software and validation

    Energy Technology Data Exchange (ETDEWEB)

    Fakra, A.H., E-mail: fakra@univ-reunion.f [Physics and Mathematical Engineering Laboratory for Energy and Environment (PIMENT), University of La Reunion, 117 rue du General Ailleret, 97430 Le Tampon (French Overseas Dpt.), Reunion (France); Miranville, F.; Boyer, H.; Guichard, S. [Physics and Mathematical Engineering Laboratory for Energy and Environment (PIMENT), University of La Reunion, 117 rue du General Ailleret, 97430 Le Tampon (French Overseas Dpt.), Reunion (France)

    2011-07-15

    Research highlights: {yields} This study presents a new model capable to simulate indoor daylighting. {yields} The model was introduced in research software called CODYRUN. {yields} The validation of the code was realized from a lot of tests cases. -- Abstract: Many models exist in the scientific literature for determining indoor daylighting values. They are classified in three categories: numerical, simplified and empirical models. Nevertheless, each of these categories of models are not convenient for every application. Indeed, the numerical model requires high calculation time; conditions of use of the simplified models are limited, and experimental models need not only important financial resources but also a perfect control of experimental devices (e.g. scale model), as well as climatic characteristics of the location (e.g. in situ experiment). In this article, a new model based on a combination of multiple simplified models is established. The objective is to improve this category of model. The originality of our paper relies on the coupling of several simplified models of indoor daylighting calculations. The accuracy of the simulation code, introduced into CODYRUN software to simulate correctly indoor illuminance, is then verified. Besides, the software consists of a numerical building simulation code, developed in the Physics and Mathematical Engineering Laboratory for Energy and Environment (PIMENT) at the University of Reunion. Initially dedicated to the thermal, airflow and hydrous phenomena in the buildings, the software has been completed for the calculation of indoor daylighting. New models and algorithms - which rely on a semi-detailed approach - will be presented in this paper. In order to validate the accuracy of the integrated models, many test cases have been considered as analytical, inter-software comparisons and experimental comparisons. In order to prove the accuracy of the new model - which can properly simulate the illuminance - a

  6. Daylight illumination-color-contrast tables for full-form objects naturally illuminated objects

    CERN Document Server

    Nagel, M

    1978-01-01

    Daylight Illumination-Color-Contrast Tables for Full-form Objects is the result of a major computational project concerning the illumination, color, and contrast conditions in naturally illuminated objects. The project from which this two-chapter book is derived is originally conceived in support of the various remote sensing and image processing activities of the Deutsche Forschungs- und Versuchsanstalt für Luft- und Raumfahrt, Oberpfaffenhofen, West Germany DFVLR, in particular, those depending on the quantitative photometric and colorimetric evaluation of photographs and other environmental

  7. Integrated control of sun shades, daylight and artificial light; Integreret regulering af solafskaermning, dagslys og kunstlys

    Energy Technology Data Exchange (ETDEWEB)

    Johnsen, K.; Christoffersen, J.; Soerensen, Henrik; Jessen, G.

    2011-07-01

    The project established a basis of calculation and a practical basis for optimum choice of solar shading and integrated control strategies for both new buildings and for office, commercial and institutional buildings to be renovated with new calculation models for controlling solar shading integrated in the BSim program. A complete and applicable model for optimum, integrated solar shading control was established, focusing on thermal and visual comfort criteria towards energy consumption for heating, cooling and lighting. A prototype was tested in the daylight laboratory at Danish Building Research Institute-Aalborg University and at University of Southern Denmark. (LN)

  8. Yellowing of coated papers under the action of heat, daylight radiation, and nitrogen oxide gas

    International Nuclear Information System (INIS)

    Mailly, V.; Le Nest, J.F.; Tosio, J.M.S.; Silvy, J.

    1997-01-01

    In the area of coated papers, a high degree of whiteness is often required to carry a quality image. Coated papers however are sensitive to the environment where they are stored and have tendency to yellow. The aim of this work was to study the influence of(i) daylight radiation and (ii) nitrogen oxide gas (NO2 ) on the yellowing of coated papers. In a previous study (l), we had established the presence of NO2 in the environment of some coating machines because of the transformation of ammonium hydroxide (NH4 OH, a component of some coating colors) into nitrogen oxide through the burners of hot air supplier-systems

  9. Simulating the Daylight Performance of Complex Fenestration Systems Using Bidirectional Scattering Distribution Functions within Radiance

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Gregory; Mistrick, Ph.D., Richard; Lee, Eleanor; McNeil, Andrew; Jonsson, Ph.D., Jacob

    2011-01-21

    We describe two methods which rely on bidirectional scattering distribution functions (BSDFs) to model the daylighting performance of complex fenestration systems (CFS), enabling greater flexibility and accuracy in evaluating arbitrary assemblies of glazing, shading, and other optically-complex coplanar window systems. Two tools within Radiance enable a) efficient annual performance evaluations of CFS, and b) accurate renderings of CFS despite the loss of spatial resolution associated with low-resolution BSDF datasets for inhomogeneous systems. Validation, accuracy, and limitations of the methods are discussed.

  10. Daylight saving time can decrease the frequency of wildlife–vehicle collisions

    Science.gov (United States)

    Ellis, William A.; FitzGibbon, Sean I.; Barth, Benjamin J.; Niehaus, Amanda C.; David, Gwendolyn K.; Taylor, Brendan D.; Matsushige, Helena; Melzer, Alistair; Bercovitch, Fred B.; Carrick, Frank; Jones, Darryl N.; Dexter, Cathryn; Gillett, Amber; Predavec, Martin; Lunney, Dan

    2016-01-01

    Daylight saving time (DST) could reduce collisions with wildlife by changing the timing of commuter traffic relative to the behaviour of nocturnal animals. To test this idea, we tracked wild koalas (Phascolarctos cinereus) in southeast Queensland, where koalas have declined by 80% in the last 20 years, and compared their movements with traffic patterns along roads where they are often killed. Using a simple model, we found that DST could decrease collisions with koalas by 8% on weekdays and 11% at weekends, simply by shifting the timing of traffic relative to darkness. Wildlife conservation and road safety should become part of the debate on DST. PMID:27881767

  11. Does extending daylight saving time save energy? Evidence from an Australian experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kellogg, R. [California Univ., Berkeley, CA (United States). Dept. of Agricultural and Resource Economics; Wolff, H. [California Univ., Berkeley, CA (United States). Dept. of Agricultural and Resource Economics]|[Forschungsinstitut zur Zukunft der Arbeit (IZA), Bonn (Germany)

    2007-03-15

    Several countries are considering extending Daylight Saving Time (DST) in order to conserve energy, and the U.S. will extend DST by one month beginning in 2007. However, projections that these extensions will reduce electricity consumption rely on extrapolations and simulations rather than empirical evidence. This paper, in contrast, examines a quasiexperiment in which parts of Australia extended DST in 2000 to facilitate the Sydney Olympics. Using detailed panel data and a triple differences specification, we show that the extension did not conserve electricity, and that a prominent simulation model overstates electricity savings when it is applied to Australia. (orig.)

  12. Development of new types of sun shielding systems based on daylight conducting sun shielding glass slats; Udvikling af nye typer solafskaermningssystemer baseret paa dagslysdirigerende solafskaermende glaslameller

    Energy Technology Data Exchange (ETDEWEB)

    Iversen, A.; Svendsen, Svend (Danmarks Tekniske Univ., DTU Byg, Kgs. Lyngby (Denmark)); Laustsen, J.B. (NIRAS A/S (Denmark)); Traberg-Borup, S.; Johnsen, Kjeld (Statens Byggeforskningsinstitut, Aalborg Univ. (Denmark))

    2009-11-15

    The project has developed a new solar shading system consisting of reflective reflective glass slats, which both must act as general sun shading and also be able to improve daylight conditions inside the building when it's needed, by reflecting light further into the room. Simulations with the program IESve / Radiance are performed of daylight conditions in an office room using the developed solar shading concept. The calculation model is used to optimize the glass slat system's shape and dimensions (slat angle, width and distance). The calculations have shown that a slat angle of 30 degrees gives the best daylight conducting effect in overcast weather. At this position, compared with the same facade without sun shading, a slight reduction of daylight factor close to the windows is obtained while the back of the room is largely unchanged. Compared with traditional slat systems the reflective glass slats provide higher daylight factors in the building. Daylight measurements are performed in a daylight laboratory. Measurements show that the daylight factor in cloudy weather is reduced by approx. 20% 1.2 m from the facade where there are usually plenty of light while it is unchanged or slightly higher at the back of the room where there often are problems with too little daylight. On a clear day with direct sunlight and the reflective slats in shading position the result is a reduction of illumination through the whole room. The developed sun shading system reduces sun irradiance in reflective position without diminishing daylight conditions in the building under overcast conditions when the slats are angled in daylight conducting position. The glass slat system's effect on the thermal indoor environment and energy consumption are analyzed using calculations in the program BSim and by measurements of the sun shading system mounted in the Passys test cell at the Technical University of Denmark. (ln)

  13. Modified optical fiber daylighting system with sunlight transportation in free space.

    Science.gov (United States)

    Vu, Ngoc-Hai; Pham, Thanh-Tuan; Shin, Seoyong

    2016-12-26

    We present the design, optical simulation, and experiment of a modified optical fiber daylighting system (M-OFDS) for indoor lighting. The M-OFDS is comprised of three sub-systems: concentration, collimation, and distribution. The concentration part is formed by coupling a Fresnel lens with a large-core plastic optical fiber. The sunlight collected by the concentration sub-system is propagated in a plastic optical fiber and then collimated by the collimator, which is a combination of a parabolic mirror and a convex lens. The collimated beam of sunlight travels in free space and is guided to the interior by directing flat mirrors, where it is diffused uniformly by a distributor. All parameters of the system are calculated theoretically. Based on the designed system, our simulation results demonstrated a maximum optical efficiency of 71%. The simulation results also showed that sunlight could be delivered to the illumination destination at distance of 30 m. A prototype of the M-OFDS was fabricated, and preliminary experiments were performed outdoors. The simulation results and experimental results confirmed that the M-OFDS was designed effectively. A large-scale system constructed by several M-OFDSs is also proposed. The results showed that the presented optical fiber daylighting system is a strong candidate for an inexpensive and highly efficient application of solar energy in buildings.

  14. Cloud and radiance measurements with the VIS/NIR Daylight Whole Sky Imager at Lindenberg (Germany)

    Energy Technology Data Exchange (ETDEWEB)

    Feister, U. [Deutscher Wetterdienst, Meteorologisches Observatorium Lindenberg (Germany); Shields, J. [Scripps Inst. of Oceanography, Univ. of California, San Diego (United States)

    2005-10-01

    Ground-based cloud data acquired with the whole sky imager (WSI) are analyzed in relation to measurements of solar radiation performed at the Lindenberg Meteorological Observatory. Cloud fractions derived by the cloud detection algorithm from WSI images acquired during daylight hours between 2002 and 2004 are compared with conventional cloud observations for the two sites Potsdam and Lindenberg, and also with ceilometer data of cloud-base heights at Lindenberg. The comparison statistics are discussed in the context of different principles of measurement. A few case studies illustrate the strong scattering effect of clouds on solar radiance and irradiance measured at the ground in different spectral regions. Particularly clouds close to the apparent position of the sun lead to strong enhancements of solar diffuse irradiance incident on horizontal planes and hemispheres that substantially exceed corresponding clear-sky values. Irradiances derived from WSI sky radiance fields are shown in comparison to pyranometer data of diffuse irradiance and radiative transfer model calculations performed for clear sky conditions. Examples of spectral sky radiances with moving contrails illustrate the significant enhancement the contrails have compared to clear sky, even though they may have a relatively small direct effect on global irradiance values. As contrails are observed at Lindenberg for about 18 to 19% of daylight hours, and part of them become clouds, the indirect impact of these changes on solar irradiance received at the ground may not be negligible. (orig.)

  15. Development of Optical Fiber-Based Daylighting System and Its Comparison

    Directory of Open Access Journals (Sweden)

    Irfan Ullah

    2015-07-01

    Full Text Available Fiber-optic daylighting systems have been shown to be a promising and effective way to transmit sunlight in the interior space whilst reducing electric lighting energy consumption. To increase efficiency in terms of providing uniform illumination in the interior, the current need is to illuminate optical fiber-bundle with uniform light flux. To this end, we propose a method for achieving collimated light, which illuminates the fiber-bundle uniformly. Light is collected through a parabolic concentrator and focused toward a collimating lens, which distributes the light over each optical fiber. An optics diffusing structure is utilized at the end side of the fiber bundle to spread light in the interior. The results clearly reveal that the efficiency in terms of uniform illumination, which also reduces the heat problem for optical fibers, is improved. Furthermore, a comparison study is conducted between current and previous approaches. As a result, the proposed daylighting system turns out convenient in terms of energy saving and reduction in greenhouse gas emissions.

  16. Light-scattering properties of a Venetian blind slat used for daylighting applications

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Annica M. [Department of Engineering Sciences, Angstroem Laboratory, Uppsala University (Sweden); Jonsson, Jacob C. [Environmental Energy Technology Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

    2010-12-15

    The low cost, simplicity, and aesthetic appearance of external and internal shading devices, make them commonly used for daylighting and glare-control applications. Shading devices, such as Venetian blinds, screens, and roller shades, generally exhibit light scattering and/or light redirecting properties. This requires the bi-directional scattering distribution function (BSDF) of the material to be known in order to accurately predict the daylight distribution and energy flow through the fenestration system. Acquiring the complete BSDF is not a straightforward task, and to complete the process it is often required that a model is used to complement the measured data. In this project, a Venetian blind slat with a white top surface and a brushed aluminum bottom surface was optically characterized. A goniophotometer and an integrating sphere spectrophotometer were used to determine the angle resolved and hemispherical reflectance of the sample, respectively. The acquired data were fitted to a scattering model providing one Lambertian and one angle dependent description of the surface properties. These were used in combination with raytracing to obtain the complete BSDFs of the Venetian blind system. (author)

  17. Comparative Study of Two Daylighting Analysis Methods with Regard to Window Orientation and Interior Wall Reflectance

    Directory of Open Access Journals (Sweden)

    Yeo Beom Yoon

    2014-09-01

    Full Text Available The accuracy and speed of the daylighting analysis developed for use in EnergyPlus is better than its predecessors. In EnergyPlus, the detailed method uses the Split-flux algorithm whereas the DElight method uses the Radiosity algorithm. Many existing studies have addressed the two methods, either individually or compared with other daylight analysis methods like Ray tracing but still there is lack of detailed comparative study of these two methods. Our previous studies show that the Split-flux method overestimates the illuminance, especially for the areas away from the window. The Radiosity method has the advantage of accurately predicting this illuminance because of how it deals with the diffuse light. For this study, the EnergyPlus model, which has been calibrated using data measured in a real building in previous studies, has also been used. The calibrated model has a south oriented window only. This model is then used to analyze the interior illuminance inside the room for north, west and east orientation of the window by rotating the model and by changing the wall reflectance of the model with south oriented window. Direct and diffuse component of the illuminance as well as the algorithms have been compared for a detailed analysis.

  18. STUDI SIMULASI MODEL PENERANGAN ALAMI (DAYLIGHTING RUANG PADA BANGUNAN FASILITAS PENDIDIKAN TINGGI DENGAN SUPERLITE 2.0

    Directory of Open Access Journals (Sweden)

    Hanni Elitasari Mahaputri

    2012-08-01

    Full Text Available Daylight was the only efficient source of light available for building. Therefore, architecture was dominated by the goal of creating openings large enough to distribute daylight to building interiors. It is important to understand the amount of natural light penetration when outdoor obstruction are displaced in order to propose optimum external shading strategies as design solutions. This paper presents a study of the daylight factor and daylight contourt approaches and also investigates the effect of outdoor obstruction displacement on natural-light penetration of a specific room in higher-education building facility. The interior daylight illuminance data were simulated and analyzed using Superlite 2.0. The result shows that several effects of the external obstruction displacement as shading provider, depending on transmitted natural-light penetration, which determine the better consideration option in designing landscape surround building, especially in hot humid climates. Sinar matahari merupakan sumber penerangan yang efisien bagi bangunan. Tujuan utama dalam arsitektur adalah merancang bukaan pencahayaan yang cukup besar bagi bangunan untuk mendistribusikan cahaya ke bagian dalam bangunan. Sangat penting untuk mengetahui besar penetrasi penerangan alami yang masuk ke dalam ruang bila di luar bangunan diletakkan suatu halangan sebagai salah satu solusi disain dengan mengoptimalkan strategi perancangan pem­bayangan lingkungan. Makalah ini membahas tentang kajian pendekatan faktor penerangan alami (daylight factor dan koefisien penerangan alami, serta mengamati pengaruh perletakan halangan lingkungan terhadap penetrasi penerangan alami suatu ruang fasilitas pendidikan tinggi. Data illuminasi penerangan interior disimulasikan dan dianalisa menggunakan software Superlite 2.0. Hasil penelitian menunjukkan beberapa pengaruh perletakan halangan lingkungan sebagai elemen pembayangan lingkungan berkaitan dengan penetrasi cahaya alami, yang

  19. Low levels of vitamin D poorly responsive to daylight exposure in patients with therapy-resistant schizophrenia.

    Science.gov (United States)

    Bogers, Jan P.A.M.; Bostoen, Tijmen; Broekman, Theo G.

    2016-01-01

    Low vitamin D levels are associated with schizophrenia, but the possible association between vitamin D levels and illness severity or duration of exposure to daylight has barely been investigated. To compare vitamin D levels in therapy-refractory severely ill schizophrenia patients and members of staff. To investigate the influence of daylight exposure on vitamin D levels in patients. Vitamin D was measured in patients with therapy-resistant schizophrenia in April, after the winter, and in patients and staff members in June, after an exceptionally sunny spring. Vitamin D levels in April and June were compared in patients, and levels in June were compared in patients and staff. The influence of daylight was taken into account by comparing the time patients spent outdoors during the day with the recommended minimum time for adequate vitamin D synthesis, and by comparing time spent outdoors in patients and staff. Patients had high rates of vitamin D deficiency (79-90%) and lower levels of vitamin D than staff members (p vitamin D levels did not normalize, despite the considerably longer than recommended exposure of the skin to daylight (p vitamin D deficiency of therapy-resistant schizophrenia patients is pronounced and cannot be explained by differences in skin pigmentation or by an inactive, indoor lifestyle on the ward. Even theoretically sufficient exposure of the patients to daylight did not ameliorate the low vitamin D levels. While vitamin D deficiency probably plays a role in somatic health problems, it may also play a role in schizophrenia. Interestingly, exposure to daylight during an unusually sunny spring was not sufficient to correct the vitamin D deficiency seen in the patients. This emphasizes the need to measure and correct vitamin D levels in these patients.

  20. Annual dynamics of daylight variability and contrast a simulation-based approach to quantifying visual effects in architecture

    CERN Document Server

    Rockcastle, Siobhan

    2013-01-01

    Daylight is a dynamic source of illumination in architectural space, creating diverse and ephemeral configurations of light and shadow within the built environment. Perceptual qualities of daylight, such as contrast and temporal variability, are essential to our understanding of both material and visual effects in architecture. Although spatial contrast and light variability are fundamental to the visual experience of architecture, architects still rely primarily on intuition to evaluate their designs because there are few metrics that address these factors. Through an analysis of contemporary

  1. Design methodology and criteria for daylight and thermal comfort in nearly-zero energy office buildings in Nordic climate

    DEFF Research Database (Denmark)

    Karlsen, Line Røseth

    The objective of this PhD thesis was to arrange for an integrated building design with respect to thermal comfort, daylighting and energy use, applicable for office buildings in Nordic climate. In order to achieve this, it is suggested that modelling of mean radiant temperature (MRT) should...... into the simulation tool IDA ICE. Furthermore, the control of solar shading is given attention, since it is a crucial link between the thermal and daylighting performance. The thesis presents results of an occupant survey with 46 subjects, which was carried out to investigate occupants’ preferences towards...

  2. Empirical assessment of a prismatic daylight-redirecting window film in a full-scale office testbed

    Energy Technology Data Exchange (ETDEWEB)

    Thanachareonkit, Anothai; Lee, Eleanor S.; McNeil, Andrew

    2013-08-31

    Daylight redirecting systems with vertical windows have the potential to offset lighting energy use in deep perimeter zones. Microstructured prismatic window films can be manufactured using low-cost, roll-to-roll fabrication methods and adhered to the inside surface of existing windows as a retrofit measure or installed as a replacement insulating glass unit in the clerestory portion of the window wall. A clear film patterned with linear, 50-250 micrometer high, four-sided asymmetrical prisms was fabricated and installed in the south-facing, clerestory low-e, clear glazed windows of a full-scale testbed facility. Views through the film were distorted. The film was evaluated in a sunny climate over a two-year period to gauge daylighting and visual comfort performance. The daylighting aperture was small (window-towall ratio of 0.18) and the lower windows were blocked off to isolate the evaluation to the window film. Workplane illuminance measurements were made in the 4.6 m (15 ft) deep room furnished as a private office. Analysis of discomfort glare was conducted using high dynamic range imaging coupled with the evalglare software tool, which computes the daylight glare probability and other metrics used to evaluate visual discomfort. The window film was found to result in perceptible levels of discomfort glare on clear sunny days from the most conservative view point in the rear of the room looking toward the window. Daylight illuminance levels at the rear of the room were significantly increased above the reference window condition, which was defined as the same glazed clerestory window but with an interior Venetian blind (slat angle set to the cut-off angle), for the equinox to winter solstice period on clear sunny days. For partly cloudy and overcast sky conditions, daylight levels were improved slightly. To reduce glare, the daylighting film was coupled with a diffusing film in an insulating glazing unit. The diffusing film retained the directionality of the

  3. The impact of changing solar screen rotation angle and its opening aspect ratios on Daylight Availability in residential desert buildings

    KAUST Repository

    Sherif, Ahmed H.

    2012-11-01

    In desert sunny clear-sky regions solar penetration can become excessive. This can cause non-uniform daylight distribution, glare and high solar heat gain, affecting both visual and thermal comfort. Shading devices, such as solar screens, were usually used to diffuse and prevent direct solar penetration into spaces. This paper investigates the impact of changing solar screen axial rotation angle and screen opening aspect ratio on daylighting performance in a typical residential living room space under the desert sunny clear-sky. The larger aim is to arrive at efficient solar screen designs that suit the different orientations.The study was divided into three consecutive phases. In phase one, the effect of the two parameters on Daylight Availability was tested. The solar screen was axially rotated by three different angles at 10° increments. Also, the aspect ratio of the screen opening in both horizontal and vertical directions was changed systematically. Simulation was conducted using the annual Daylight Dynamic Performance Metrics (DDPMs). In phase two, the Annual Daylight Glare Probability (DGP) metric was evaluated for the cases that were found adequate in phase one. In the third phase, the annual solar energy transmittance through the screen was calculated for the cases that achieved acceptable performance in the two previous phases in order to identify the more energy efficient screens.Solar screens with openings having horizontal aspect ratios were found to be the most effective, while those with vertical aspect ratios were achieved the lowest performance. In the North orientation, since almost all the cases that were tested in this research provided acceptable daylighting performance, the designer now have a variety of options to choose from. Preference should be given to screen openings of horizontal aspect ratios, especially the 12:1 and 18:1 (H:V) screens that achieved the best performance where 92% of the space was " daylit" in comparison with only 53

  4. Daylight for energy-saving lamps. Recognizing with lighting sources free of charge; Tageslicht vor Energiesparlampen. Kostenlos verfuegbare Lichtquellen einplanen

    Energy Technology Data Exchange (ETDEWEB)

    David, Holger

    2010-07-01

    With saving energy in the lighting, politics, economics and private households set on compact fluorescent lamps, so called energy-saving lamps. A more economical and pollution free alternative is the increased use of daylight, which is free of charge and felt more pleasant by humans.

  5. Switching From Conventional Photodynamic Therapy to Daylight Photodynamic Therapy For Actinic Keratoses: Systematic Review and Meta-analysis.

    Science.gov (United States)

    Tomás-Velázquez, A; Redondo, P

    2017-05-01

    Actinic keratosis is a precursor lesion to the most common nonmelanoma skin cancer. Conventional photodynamic therapy (PDT) has been shown to be effective, but the procedure is time-consuming, can be very painful, and requires infrastructure. These shortcomings led to the emergence of daylight PDT. To obtain a global estimate of efficacy, we undertook a systematic literature review and performed a meta-analysis of the available evidence on the efficacy and safety of daylight PDT as compared to conventional PDT in the treatment of actinic keratosis and/or field cancerization. The conclusion is that the difference in efficacy is clinically negligible (global estimate of the mean response rate difference, -3.69%; 95% CI, -6.54% to -0.84%). The adverse effects of daylight PDT are mild and localized (79% of patients report no discomfort), and patients report less pain (P<.001). Daylight PDT gives good to excellent cosmetic results in more than 90% of patients, and patient satisfaction is greater (P<.001). Copyright © 2016 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. Photoageing of Baltic amber-influence of daylight radiation behind window glass on surface colour and chemistry

    DEFF Research Database (Denmark)

    Shashoua, Yvonne

    2011-01-01

    The aim of this study was to provide evidence about the interaction between Baltic amber and daylight behind window glass, essential to understanding the mechanisms by which the material degrades in museum environments and to propose techniques for preventive conservation based on the control...

  7. Students' Perception of Daylight Illumination in the School Workshop as a Determinant for Effective Students' Task Performance in Workshop Practice

    Science.gov (United States)

    Amasuomo, Japo Oweikeye Morto; Alio, Abigail Ngozi

    2013-01-01

    The study investigated daylight illumination in the school workshop as a determinant for effective students' task performance in workshop practice. 183 NCE Technical students in 300 Level which comprised of 73 and 112 students from Federal Colleges of Education (Technical), Asaba and Omoku, Nigeria respectively during the 2008/2009 academic…

  8. Lost sleep and cyberloafing: Evidence from the laboratory and a daylight saving time quasi-experiment.

    Science.gov (United States)

    Wagner, David T; Barnes, Christopher M; Lim, Vivien K G; Ferris, D Lance

    2012-09-01

    The Internet is a powerful tool that has changed the way people work. However, the ubiquity of the Internet has led to a new workplace threat to productivity-cyberloafing. Building on the ego depletion model of self-regulation, we examine how lost and low-quality sleep influence employee cyberloafing behaviors and how individual differences in conscientiousness moderate these effects. We also demonstrate that the shift to Daylight Saving Time (DST) results in a dramatic increase in cyberloafing behavior at the national level. We first tested the DST-cyberloafing relation through a national quasi-experiment, then directly tested the relation between sleep and cyberloafing in a closely controlled laboratory setting. We discuss the implications of our findings for theory, practice, and future research.

  9. Dynamic window daylighting systems: electropolymeric technology for solar responsive building envelopes

    Science.gov (United States)

    Krietemeyer, Elizabeth A.; Smith, Shane I.; Dyson, Anna H.

    2011-04-01

    Human health and energy problems associated with the lack of control of sunlight in contemporary buildings have necessitated research into dynamic windows for energy efficient buildings. Existing window technologies have made moderate progress towards greater energy performance for facades but remain limited in their response to dynamic solar conditions, building energy requirements, and variable user preferences for visual comfort. Recent developments in electropolymeric display technology provide opportunities to transfer electroactive polymers to windows that can achieve high levels of geometric and spectral selectivity through the building envelope in order to meet the lighting, thermal and user requirements of occupied spaces. Experimental simulations that investigate daylight quality, energy performance, and architectural effects of electropolymeric glazing technology are presented.

  10. Discomfort glare with complex fenestration systems and the impact on energy use when using daylighting control

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Sabine; McNeil, Andrew; Lee, Eleanor S.; Kalyanam, Raghuram

    2015-11-03

    Glare is a frequent issue in highly glazed buildings. A modelling approach is presented that uses discomfort glare probability and discomfort glare index as metrics to determine occupants’ behaviour. A glare control algorithm that actuated an interior shade for glare protection based on the predicted perception was implemented in a building simulation program. A reference case with a state-of-the-art base glazing was compared to the same glazing but with five different complex fenestration systems, i.e., exterior shades. The windows with exterior shades showed significant variations in glare frequencies. Energy use intensity in a prototypical office building with daylighting controls was greatly influenced for the systems with frequent glare occurrence. While the base glazing could benefit from glare control, some of the exterior shades showed significantly greater energy use when discomfort glare-based operation of interior shades was considered.

  11. Impact of daylight savings time on spontaneous pregnancy loss in in vitro fertilization patients.

    Science.gov (United States)

    Liu, Constance; Politch, Joseph A; Cullerton, Evan; Go, Kathryn; Pang, Samuel; Kuohung, Wendy

    2017-01-01

    Transition into daylight savings time (DST) has studied negative impacts on health, but little is known regarding impact on fertility. This retrospective cohort study evaluates DST impact on pregnancy and pregnancy loss rates in 1,654 autologous in vitro fertilization cycles (2009 to 2012). Study groups were identified based on the relationship of DST to embryo transfer. Pregnancy rates were similar in Spring and Fall (41.4%, 42.2%). Pregnancy loss rates were also comparable between Spring and Fall (15.5%, 17.1%), but rates of loss were significantly higher in Spring when DST occurred after embryo transfer (24.3%). Loss was marked in patients with a history of prior spontaneous pregnancy loss (60.5%).

  12. Window Material Daylighting Performance Assessment Algorithm: Comparing Radiosity and Split-Flux Methods

    Directory of Open Access Journals (Sweden)

    Yeo Beom Yoon

    2014-04-01

    Full Text Available Windows are the primary aperture to introduce solar radiation to the interior space of a building. This experiment explores the use of EnergyPlus software for analyzing the illuminance level on the floor of a room with reference to its distance from the window. For this experiment, a double clear glass window has been used. The preliminary modelling in EnergyPlus showed a consistent result with the experimentally monitored data in real time. EnergyPlus has two mainly used daylighting algorithms: DElight method employing radiosity technique and Detailed method employing split-flux technique. Further analysis for illuminance using DElight and Detailed methods showed significant difference in the results. Finally, we compared the algorithms of the two analysis methods in EnergyPlus.

  13. Effect of daylight and gamma-radiation on the colour of fabricated textile polymers

    International Nuclear Information System (INIS)

    Wahab, L.A.; Saad, M.M.; Talaat, M.H.

    2003-01-01

    The effects of gamma-irradiation (0-60 mrad) and natural daylight (0-6 months) on the color and other properties of undyed textile polymers (cotton, nylon-6, polyester/cotton blend and wool/polyester blend) were investigated using optical spectroscopy. The change in color was estimated by yellowness index (Y1) and color difference (Delta E) between the irradiated and unirradiated samples. The analysis used for dosimeter is mainly spectrophotometer in the UV and visible spectrum. Systems having a reproducible response are selected. In the case of cotton fabric the change in color and reflection are showing a promise for dosimeter of gamma-radiation. It was concluded that the whiteness (W) of synthetic and blend fabrics decreased much more than that of cotton fabrics

  14. Daylighting and Cooling of Atrium Buildings in Warm Climates: Impact of the Top-Fenestration and Wall Mass Area.

    Science.gov (United States)

    Atif, Morad Rachid

    1992-01-01

    Sun-lighting and daylighting contribute greatly to the aesthetic value of an atrium. However, today's atria are often found either over-lit with extensive cooling loads, or under-lit requiring increased artificial lighting loads. The increase of the top-glazing area increases the cooling loads and decreases the lighting loads. The increase of the mass in the atrium walls decreases the maximum atrium temperature and the cooling loads. Furthermore, the mass distribution and its reflectance affect the lighting levels at the atrium floor. The purpose of this study is to investigate the simultaneous impact of the top-fenestration and the mass and reflectance of atrium walls on the cooling and daylighting performance of atria in warm climates. It attempts to determine the optimum top-fenestration for efficient daylighting and low cooling loads. The daylighting performance was evaluated through illumination measurements in physical models in a sky simulator. The cooling performance was evaluated using the software TRNSYS 13.1. Two types of top-fenestration were tested: horizontal and vertical south-facing, each with three alternate areas. The variations of the atrium walls included materials (standard frame and heavyweight concrete) and percentage and reflectance of the solid area. Two and four-story atria were considered, each with square and linear configuration. The performance was evaluated for three warm climates. The optimum top-fenestration for efficient daylighting was determined. The daylighting prediction algorithm was extended to include the effective reflectance of the atrium walls. The increase of mass in the atrium walls significantly decreased the atrium temperature range, the maximum atrium temperature, and the cooling loads. This impact decreased from horizontal to vertical south-facing top-glazing. The vertical south-facing top-glazing and, to a lesser degree, the reduction of the glazed atrium cover by 50% had more cooling benefits than increasing the

  15. Impact of daylight saving time on road traffic collision risk: a systematic review.

    Science.gov (United States)

    Carey, Rachel N; Sarma, Kiran M

    2017-07-02

    Bills have been put forward in the UK and Republic of Ireland proposing a move to Central European Time (CET). Proponents argue that such a change will have benefits for road safety, with daylight being shifted from the morning, when collision risk is lower, to the evening, when risk is higher. Studies examining the impact of daylight saving time (DST) on road traffic collision risk can help inform the debate on the potential road safety benefits of a move to CET. The objective of this systematic review was to examine the impact of DST on collision risk. Major electronic databases were searched, with no restrictions as to date of publication (the last search was performed in January 2017). Access to unpublished reports was requested through an international expert group. Studies that provided a quantitative analysis of the effect of DST on road safety-related outcomes were included. The primary outcomes of interest were road traffic collisions, injuries and fatalities. Twenty-four studies met the inclusion criteria. Seventeen examined the short-term impact of transitions around DST and 12 examined long-term effects. Findings from the short-term studies were inconsistent. The long-term findings suggested a positive effect of DST. However, this cannot be attributed solely to DST, as a range of road collision risk factors vary over time. The evidence from this review cannot support or refute the assertion that a permanent shift in light from morning to evening will have a road safety benefit. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  16. Economic analysis of the daylight-linked lighting control system in office buildings

    Energy Technology Data Exchange (ETDEWEB)

    Yang, In-Ho; Nam, Eun-Ji [Department of Architectural Engineering, College of Engineering, Dongguk University, 26-3, Pil-dong, Chung-gu, Seoul 100-715 (Korea)

    2010-08-15

    The objective of this study is to perform an economic analysis of the daylight-linked automatic on/off lighting control system installed for the purpose of energy savings in office buildings. For this, a building was chosen as a typical example, and the energy cost was calculated by using the daylight and building energy analysis simulation. When the lighting control was utilized, an economic analysis was performed using a payback period that was calculated by comparing the initial cost of installing the lighting control system with the annual energy cost which was reduced thanks to the application of the lighting control. The results showed that the lighting energy consumption, when the lighting control was applied, was reduced by an average of 30.5% compared with the case that there was not lighting control applied. Also, the result for total energy consumption showed that, when lighting control was applied, this was reduced by 8.5% when the glazing ratio was 100%, 8.2% for 80%, and 7.6% for 60% when compared to non-application. The payback period was analyzed in terms of the number of floors in a building; 10 floors, 20 floors, 30 floors, and 40 floors. Hence, the building with 40 floors and glazing ratio 100% resulted in the shortest payback period of 8.8 years, the building with 10 floors and glazing ratio 60% resulted in the longest period of 12.7 years. In other words, the larger the glazing ratio and the number of building floors are, the shorter the payback period is. (author)

  17. Analysis of impact of daylight time savings on energy use of buildings in Kuwait

    Energy Technology Data Exchange (ETDEWEB)

    Krarti, Moncef, E-mail: moncef.krarti@colorado.ed [CEAE Department, CB 428, University of Colorado, Boulder, CO 80309 (United States); Hajiah, Ali [Kuwait Institute for Scientific Research, Safat (Kuwait)

    2011-05-15

    In this paper, a detailed simulation-based analysis is conducted to assess the impact of adopting Daylight Saving Time (DST) on the electrical energy use and peak demand in Kuwait. The analysis focused on the impact of DST in the building sector since it represents 90% of electrical energy usage of Kuwait. The simulation results indicate that the adoption of DST has mixed impacts for Kuwait. While the commercial and the governmental sectors may benefit from the DST, the private residences and apartment buildings can see both their annual energy use and peak demand increase slightly by adopting DST. The overall impact of the DST implementation is rather minimal with a slight increase energy use of about 0.07% and a slight reduction in peak demand of 0.14% or about 12 MW based on 2005 electrical peak demand for Kuwait. - Research highlights: {yields} A detailed simulation-based analysis is conducted to assess the impact of adopting Daylight Saving Time (DST) on the electrical energy use and peak demand in Kuwait. {yields} The analysis focused on the impact of DST in the building sector since it represents 90% of electrical energy usage of Kuwait. {yields} It is found that while the commercial and the governmental building sectors may benefit from DST, the private residences and apartment buildings can see both their annual energy use and peak demand increase slightly by adopting DST. {yields} Since the residential sector represents the majority of the electrical load in Kuwait, DST adoption was found to cause slight increase in annual electrical energy use by about 0.07% and a slight reduction in electrical peak electrical demand by about 0.14%.

  18. Analysis of impact of daylight time savings on energy use of buildings in Kuwait

    International Nuclear Information System (INIS)

    Krarti, Moncef; Hajiah, Ali

    2011-01-01

    In this paper, a detailed simulation-based analysis is conducted to assess the impact of adopting Daylight Saving Time (DST) on the electrical energy use and peak demand in Kuwait. The analysis focused on the impact of DST in the building sector since it represents 90% of electrical energy usage of Kuwait. The simulation results indicate that the adoption of DST has mixed impacts for Kuwait. While the commercial and the governmental sectors may benefit from the DST, the private residences and apartment buildings can see both their annual energy use and peak demand increase slightly by adopting DST. The overall impact of the DST implementation is rather minimal with a slight increase energy use of about 0.07% and a slight reduction in peak demand of 0.14% or about 12 MW based on 2005 electrical peak demand for Kuwait. - Research highlights: → A detailed simulation-based analysis is conducted to assess the impact of adopting Daylight Saving Time (DST) on the electrical energy use and peak demand in Kuwait. → The analysis focused on the impact of DST in the building sector since it represents 90% of electrical energy usage of Kuwait. → It is found that while the commercial and the governmental building sectors may benefit from DST, the private residences and apartment buildings can see both their annual energy use and peak demand increase slightly by adopting DST. → Since the residential sector represents the majority of the electrical load in Kuwait, DST adoption was found to cause slight increase in annual electrical energy use by about 0.07% and a slight reduction in electrical peak electrical demand by about 0.14%.

  19. Investigating the Influence of Light Shelf Geometry Parameters on Daylight Performance and Visual Comfort, a Case Study of Educational Space in Tehran, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Moazzeni

    2016-07-01

    Full Text Available Daylight can be considered as one of the most important principles of sustainable architecture. It is unfortunate that this is neglected by designers in Tehran, a city that benefits from a significant amount of daylight and many clear sunny days during the year. Using a daylight controller system increases space natural light quality and decreases building lighting consumption by 60%. It also affects building thermal behavior, because most of them operate as shading. The light shelf is one of the passive systems for controlling daylight, mostly used with shading and installed in the upper half of the windows above eye level. The influence of light shelf parameters, such as its dimensions, shelf rotation angle and orientation on daylight efficiency and visual comfort in educational spaces is investigated in this article. Daylight simulation software and annual analysis based on climate information during space occupation hours were used. The results show that light shelf dimensions, as well as different orientations, especially in southern part, are influential in the distribution of natural light and visual comfort. At the southern orientation, increased light shelf dimensions result in an increase of the area of the work plane with suitable daylight levels by 2%–40% and a significant decrease in disturbing and intolerable glare hours.

  20. A randomized, multicentre study of directed daylight exposure times of 1½ vs. 2½ h in daylight-mediated photodynamic therapy with methyl aminolaevulinate in patients with multiple thin actinic keratoses of the face and scalp

    DEFF Research Database (Denmark)

    Wiegell, Stine; Fabricius, S; Stender, I M

    2011-01-01

    Actinic keratoses (AKs) are common dysplastic skin lesions that may differentiate into invasive squamous cell carcinomas. Although a superior cosmetic outcome of photodynamic therapy (PDT) is advantageous compared with equally effective treatments such as cryotherapy and curettage, the inconvenie......, the inconvenience of clinic attendance and discomfort during therapy are significant drawbacks. Daylight-mediated PDT could potentially reduce these and may serve as an alternative to conventional PDT....

  1. Influence of daylight on the fate of silver and zinc oxide nanoparticles in natural aquatic environments

    International Nuclear Information System (INIS)

    Odzak, Niksa; Kistler, David; Sigg, Laura

    2017-01-01

    Nanoparticles, such as silver (Ag-NP) and zinc oxide (ZnO-NP), are increasingly used in many consumer products. These nanoparticles (NPs) will likely be exposed to the aquatic environment (rain, river, lake water) and to light (visible and UV) in the products where they are applied, or after those products are discharged. Dissolution of Ag-NP and ZnO-NP is an important process because the dissolved Ag + and Zn 2+ are readily available and toxic for aquatic organisms. The objective of this study was to investigate the role of daylight (UV and visible) for the fate of engineered Ag-NP and ZnO-NPs in different types of natural waters. Ag-NP and ZnO-NP were exposed to rainwater, river Rhine, and lake waters (Greifen, Lucerne, Cristallina, Gruère) under different light conditions (no light, UV 300–400 nm and visible light 400–700 nm) for up to 8 days. Stronger agglomeration of Ag-NP was observed in the waters with higher ionic strength in comparison to those with lower ionic strength. Visible light tended to increase the dissolution of Ag-NP under most natural water conditions in comparison to dark conditions, whereas UV-light led to decreased dissolved Ag + after longer exposure time. These effects illustrate the dynamic interactions of Ag-NP with light, which may lead both to increased oxidation and to increased reduction of Ag + by organic compounds under UV-light. In the case of ZnO-NP, agglomeration occurred at higher ionic strength, but the effects of pH were predominant for dissolution, which occurred up to concentrations close to the solubility limit of ZnO(s) at pH around 8.2 and to nearly complete dissolution of ZnO-NP at lower pH (pH 4.8–6.5), with both visible and UV-light facilitating dissolution. This study thus shows that light conditions play an important role in the dissolution processes of nanoparticles. - Highlights: • Effects of visible and UV-light on dissolution of silver and zinc oxide nanoparticles were examined. • Natural waters

  2. Daylighting analysis of rooflights through model measurements in the artificial sky

    Energy Technology Data Exchange (ETDEWEB)

    Filetoht, Levente I. [University of Technnology and Economics, Budapest, Hungary (Hungary)

    2000-07-01

    In investigating the daylighting of rooflights, it can be assumed that they are behaving as luminaires-having a major role in the lighting features of the interior space. Until now there is not enough precise information on these daylighting systems, and because of this, it is difficult to predict precisely the quality and quantity of illuminance and the light distribution in the interior. The exact behavior of the rooflights are complex and sophisticated. Their features are based on their geometry, reflectance and transmittance of their non-transparent, transparent and translucent surfaces. The effect of these features can not be predicted of calculated using the traditional mathematical methods. I am investigating roof-lighting systems taking into account the complex effects of their parts, using a completely new method based on a series of model measurements under artificial sky. Investigating the roof-light as a complex system which consist of relatively large surfaces and the effects of surfaces on other surfaces. Considering the different illuminance fields of the different types of roof-lighting systems. I will be able to determine the light distribution and efficiency of the system as well. The results of this research will lead to the development of a new computer software which is beyond the scope of this paper. [Spanish] Al investigar la iluminacion de luz de dia de luces de techo puede suponerse que se estan comportando como luminarias teniendo un papel principal en las caracteristicas de iluminacion del espacio interior. Hasta ahora no existe ninguna informacion precisa de estos sistemas de iluminacion de dia y a causa de ello es dificil predecir con precision la calidad y cantidad de iluminancia y la distribucion de la luz en el interior. El comportamiento exacto de las luces de techo es complejo y sofisticado. Sus caracteristicas estan basadas en su geometria, reflectancia y trasmitancia de sus superficies no transparentes, transparentes y

  3. Impact of façade window design on energy, daylighting and thermal comfort in nearly zero-energy houses

    DEFF Research Database (Denmark)

    Vanhoutteghem, Lies; Skarning, Gunnlaug Cecilie Jensen; Hviid, Christian Anker

    2015-01-01

    a solution space defined by targets for daylighting and thermal comfort. In contrast with existing guidelines, the results show an upper limit for energy savings and utilisation of solar gains in south-oriented rooms. Instead, low U-values are needed in both north- and south oriented rooms before large......Appropriate window solutions are decisive for the design of 'nearly zero-energy' buildings with healthy and comfortable indoor environment. This paper focuses on the relationship between size, orientation and glazing properties of façade windows for different side-lit room geometries in Danish...... 'nearly zero-energy' houses. The effect of these parameters on space heating demand, daylighting and thermal environment is evaluated by means of EnergyPlus and DAYSIM and presented in charts illustrating how combinations of design parameters with minimum space heating demand can be selected within...

  4. A geostatistical analysis of IBTS data for age 2 North Sea haddock ( Melanogrammus aeglefinus ) considering daylight effects

    DEFF Research Database (Denmark)

    Wieland, Kai; Rivoirard, J.

    2001-01-01

    to ordinary kriging being most pronounced for years characterized by a high portion of night hauls and a low mean catch rate at night. This demonstrates that external drift kriging with a day/night indicator but preferably with time of day is capable of compensating successfully for daylight effects...... are included in the estimation without any correction for possible daylight effects. In the present study, ordinary kriging was used to correct for sampling irregularities and external drift kriging with a day/night indicator or a cosine function of time of day was applied to account additionally for diurnal...... differences in the catch rates. Only minor differences between the standard indices and the abundance estimates obtained by ordinary kriging were found. In contrast, the external drift kriging, particularly with time of day, yielded higher estimates of mean abundance for all years with the differences...

  5. Light-scattering properties of a woven shade-screen material used for daylighting and solar heat-gain control

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, Jacob; Jonsson, Jacob C.; Lee, Eleanor S.; Rubin, Mike

    2008-08-01

    Shade-screens are widely used in commercial buildings as a way to limit the amount of direct sunlight that can disturb people in the building. The shade screens also reduce the solar heat-gain through glazing the system. Modern energy and daylighting analysis software such as EnergyPlus and Radiance require complete scattering properties of the scattering materials in the system. In this paper a shade screen used in the LBNL daylighting testbed is characterized using a photogoniometer and a normal angle of incidence integrating sphere. The data is used to create a complete bi-directional scattering distribution function (BSDF) that can be used in simulation programs. The resulting BSDF is compared to a model BADFs, both directly and by calculating the solar heat-gain coefficient for a dual pane system using Window 6.

  6. Modeling Performance of an Airborne Infrared Sensor Used by a Man-in-the-Loop in Tactical Aircraft during Daylight Operations

    National Research Council Canada - National Science Library

    Harder, James

    1998-01-01

    .... The best monochromatic tactical aircraft displays are contrast limited during daylight operations and are able to reproduce only a fraction of the available dynamic range of current generation IR imaging sensors...

  7. Balancing the daylighting and energy performance of solar screens in residential desert buildings: Examination of screen axial rotation and opening aspect ratio

    KAUST Repository

    Sabry, Hanan; Sherif, Ahmed; Gadelhak, Mahmoud; Aly, Mohamed

    2014-01-01

    Solar screens are typically used to control solar access into building spaces. They proved their usefulness in improving the daylighting and energy performance of buildings in the hot arid desert environments which are endowed with abundance

  8. Energy Savings by Using Daylight for Basic Urban Shapes : With a Case Study of Three Different Street Types

    OpenAIRE

    Sundborg, Bengt

    2016-01-01

    During winter the sun is in short supply. But research at KTH shows that solar radiation can be facilitated while energy consumption for lighting is reduced. This provided that the buildings are appropriately designed. But, unfortunately, the sunlight is often not taken into account and the results are the opposite. The energy savings depend on good town planning where the daylight is accessible for longer periods of time during the day, both indoors and outdoors. Then, the periods of use for...

  9. Enhanced Photocatalytic Degradation of Methyl Orange Dye under the Daylight Irradiation over CN-TiO₂ Modified with OMS-2.

    Science.gov (United States)

    Hassan, Mohamed Elfatih; Chen, Jing; Liu, Guanglong; Zhu, Duanwei; Cai, Jianbo

    2014-12-12

    In this study, CN-TiO₂ was modified with cryptomelane octahedral molecular sieves (OMS-2) by the sol-gel method based on the self-assembly technique to enhance its photocatalytic activity under the daylight irradiation. The synthesized samples were characterized by X-ray diffraction (XRD), UV-vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and porosimeter analysis. The results showed that the addition of OMS-2 in the sol lead to higher Brunauer-Emmett-Teller (BET) surface area, pore volume, porosity of particle after heat treatment and the specific surface area, porosity, crystallite size and pore size distribution could be controlled by adjusting the calcination temperature. Compared to the CN-TiO₂-400 sample, CN-TiO₂/OMS-2-400 exhibited greater red shift in absorption edge of samples in visible region due to the OMS-2 coated. The enhancement of photocatalytic activity of CN-TiO₂/OMS-2 composite photocatalyst was subsequently evaluated for the degradation of the methyl orange dye under the daylight irradiation in water. The results showed that the methyl orange dye degradation rate reach to 37.8% for the CN-TiO₂/OMS-2-400 sample under the daylight irradiation for 5 h, which was higher than that of reference sample. The enhancement in daylight photocatalytic activities of the CN-TiO₂/OMS samples could be attributed to the synergistic effects of OMS-2 coated, larger surface area and red shift in adsorption edge of the prepared sample.

  10. Establishment and verification of solar radiation calculation model of glass daylighting roof in hot summer and warm winter zone in China

    OpenAIRE

    Zheng, Caidan; Wu, Peihao; Costanzo, Vincenzo; Wang, Yuchen; Yang, Xiaokun

    2017-01-01

    In this paper, solar heat gain through glass daylighting roof is deeply studied by theoretical calculation method, taking Guangzhou in the Hot Summer and Warm Winter (HSWW) zone as an example. The direct solar radiation is calculated by Bouguer formula whereas the diffuse solar radiation is calculated by Berlage formula, representing the basis for the calculation method of the solar radiation intensity through the glass daylighting roof. Through the establishment of solar radiation calculatio...

  11. Evening daylight may cause adolescents to sleep less in spring than in winter

    Science.gov (United States)

    Figueiro, Mariana G.; Rea, Mark S.

    2012-01-01

    Sleep restriction commonly experienced by adolescents can stem from greater sleep pressure by the homeostatic processes and from phase delays of the circadian system. With regard to the latter potential cause, we hypothesized that because there is more natural evening light during the spring than winter, a sample of adolescent students would be more phase delayed in spring than in winter, would have later sleep onset times and, because of fixed school schedules, would have shorter sleep durations. Sixteen eighth-grade subjects were recruited for the study. We collected sleep logs and saliva samples to determine their dim light melatonin onset (DLMO), a well-established circadian marker. Actual circadian light exposures experienced by a subset of twelve subjects over the course of seven days in winter and in spring using a personal, head-worn, circadian light measurement device are also reported here. Results showed that this sample of adolescents was exposed to significantly more circadian light in spring than in winter, especially in the evening hours when light exposure would likely delay circadian phase. Consistent with the light data, DLMO and sleep onset times were significantly more delayed, and sleep durations were significantly shorter in spring than in winter. The present ecological study of light, circadian phase, and self-reported sleep suggests that greater access to evening daylight in the spring may lead to sleep restriction in adolescents while attending school. Therefore, lighting schemes that reduce evening light in the spring may encourage longer sleep times in adolescents. PMID:20653452

  12. Daylight Management in Mediterranean Cities: When Shortage Is Not the Issue

    Directory of Open Access Journals (Sweden)

    Judit Lopez-Besora

    2016-09-01

    Full Text Available Natural resources such as daylight and sunlight are highly appreciated in countries with prevailing overcast skies. Taking advantage of this scarce resource contributes to saving energy on artificial lighting. In contrast to northern, southern European cities are distinguished by a large number of days with direct sunlight caused by a propitious climate condition. While it is a positive issue in terms of energy availability, the abundance of it can be counterproductive if management measures are not taken. Apart from the thermal consequences, lighting penetration into buildings causes a great contrast between inside and outside. This is especially critical when the visual system does not have enough time to adapt, as happens at entrance areas. The aim of this study is to analyze the light contrast between these areas and the urban outside in sunny conditions. To attain this objective, light data from five entrance spaces and their contiguous streets were analyzed and measured. The results were divided into three zones in the visual scene, showing an increasing contrast from top to bottom of the visual field. It may be concluded that interventions applied to urban areas and building pavements can improve visual adaptation in the transition zone.

  13. Exposure to Non-Extreme Solar UV Daylight: Spectral Characterization, Effects on Skin and Photoprotection

    Directory of Open Access Journals (Sweden)

    Claire Marionnet

    2014-12-01

    Full Text Available The link between chronic sun exposure of human skin and harmful clinical consequences such as photo-aging and skin cancers is now indisputable. These effects are mostly due to ultraviolet (UV rays (UVA, 320–400 nm and UVB, 280–320 nm. The UVA/UVB ratio can vary with latitude, season, hour, meteorology and ozone layer, leading to different exposure conditions. Zenithal sun exposure (for example on a beach around noon under a clear sky can rapidly induce visible and well-characterized clinical consequences such as sunburn, predominantly induced by UVB. However, a limited part of the global population is exposed daily to such intense irradiance and until recently little attention has been paid to solar exposure that does not induce any short term clinical impact. This paper will review different studies on non-extreme daily UV exposures with: (1 the characterization and the definition of the standard UV daylight and its simulation in the laboratory; (2 description of the biological and clinical effects of such UV exposure in an in vitro reconstructed human skin model and in human skin in vivo, emphasizing the contribution of UVA rays and (3 analysis of photoprotection approaches dedicated to prevent the harmful impact of such UV exposure.

  14. Exposure to non-extreme solar UV daylight: spectral characterization, effects on skin and photoprotection.

    Science.gov (United States)

    Marionnet, Claire; Tricaud, Caroline; Bernerd, Françoise

    2014-12-23

    The link between chronic sun exposure of human skin and harmful clinical consequences such as photo-aging and skin cancers is now indisputable. These effects are mostly due to ultraviolet (UV) rays (UVA, 320-400 nm and UVB, 280-320 nm). The UVA/UVB ratio can vary with latitude, season, hour, meteorology and ozone layer, leading to different exposure conditions. Zenithal sun exposure (for example on a beach around noon under a clear sky) can rapidly induce visible and well-characterized clinical consequences such as sunburn, predominantly induced by UVB. However, a limited part of the global population is exposed daily to such intense irradiance and until recently little attention has been paid to solar exposure that does not induce any short term clinical impact. This paper will review different studies on non-extreme daily UV exposures with: (1) the characterization and the definition of the standard UV daylight and its simulation in the laboratory; (2) description of the biological and clinical effects of such UV exposure in an in vitro reconstructed human skin model and in human skin in vivo, emphasizing the contribution of UVA rays and (3) analysis of photoprotection approaches dedicated to prevent the harmful impact of such UV exposure.

  15. The impact of the daylight saving time on electricity consumption-A case study from Jordan

    International Nuclear Information System (INIS)

    Awad Momani, Mohammad; Yatim, Baharudin; Ali, Mohd Alauddin Mohd

    2009-01-01

    The paper examines the impact of daylight saving time (DST) on electricity consumption in Jordan. Two types of analysis were done: the first analysis examines the impact of DST on the lighting loads based on a survey study made for residential and commercial sectors. The second examines the impact of DST on the over all electricity generation through analyzing the daily load curves (DLCs) before and after the DST onset and removal in 2000 and 2007. The results show that the application of DST during the year 2000 saves the electricity used for illumination by -0.73% but it increases the overall generation at the onset and removal of DST by 0.5% and 1.4% due to increase in the heating and cooling loads. The analysis of DLCs during the year 2007 shows similar effects as in the year 2000 except during the early morning period at the DST onset where DST decreases the demand during this time. The analysis shows that DST decreases the electricity demand at DST onset by 0.2% and increases it at DST removal by 0.3%. A possible decrease in the electricity consumption may take place if the DST is implemented from April to end of August.

  16. Effect of daylight saving time on lighting energy use: A literature review

    International Nuclear Information System (INIS)

    Aries, Myriam B.C.; Newsham, Guy R.

    2008-01-01

    The principal reason for introducing (and extending) daylight saving time (DST) was, and still is, projected energy savings, particularly for electric lighting. This paper presents a literature review concerning the effects of DST on energy use. Simple estimates suggest a reduction in national electricity use of around 0.5%, as a result of residential lighting reduction. Several studies have demonstrated effects of this size based on more complex simulations or on measured data. However, there are just as many studies that suggest no effect, and some studies suggest overall energy penalties, particularly if gasoline consumption is accounted for. There is general consensus that DST does contribute to an evening reduction in peak demand for electricity, though this may be offset by an increase in the morning. Nevertheless, the basic patterns of energy use, and the energy efficiency of buildings and equipment have changed since many of these studies were conducted. Therefore, we recommend that future energy policy decisions regarding changes to DST be preceded by high-quality research based on detailed analysis of prevailing energy use, and behaviours and systems that affect energy use. This would be timely, given the extension to DST underway in North America in 2007

  17. Robustness of circadian clocks to daylight fluctuations: hints from the picoeucaryote Ostreococcus tauri.

    Directory of Open Access Journals (Sweden)

    Quentin Thommen

    Full Text Available The development of systemic approaches in biology has put emphasis on identifying genetic modules whose behavior can be modeled accurately so as to gain insight into their structure and function. However, most gene circuits in a cell are under control of external signals and thus, quantitative agreement between experimental data and a mathematical model is difficult. Circadian biology has been one notable exception: quantitative models of the internal clock that orchestrates biological processes over the 24-hour diurnal cycle have been constructed for a few organisms, from cyanobacteria to plants and mammals. In most cases, a complex architecture with interlocked feedback loops has been evidenced. Here we present the first modeling results for the circadian clock of the green unicellular alga Ostreococcus tauri. Two plant-like clock genes have been shown to play a central role in the Ostreococcus clock. We find that their expression time profiles can be accurately reproduced by a minimal model of a two-gene transcriptional feedback loop. Remarkably, best adjustment of data recorded under light/dark alternation is obtained when assuming that the oscillator is not coupled to the diurnal cycle. This suggests that coupling to light is confined to specific time intervals and has no dynamical effect when the oscillator is entrained by the diurnal cycle. This intriguing property may reflect a strategy to minimize the impact of fluctuations in daylight intensity on the core circadian oscillator, a type of perturbation that has been rarely considered when assessing the robustness of circadian clocks.

  18. Low cost data acquisition module for evaluating the quantitative performance of daylight systems

    Energy Technology Data Exchange (ETDEWEB)

    Ciampini, F.; Scarazzato, P.S. [Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo, P.O. Box 6021, CEP 13083-852 Campinas (Brazil); Neves, A.A.R. [Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin, Departamento de Eletronica Quantica, P.O. Box 6165, 13083-970 Campinas (Brazil); Pereira, D.C.L.; Yamanaka, M.H. [Universidade de Sao Paulo, Faculdade de Arquitetura e Urbanismo, Departamento de Tecnologia da Arquitetura, Rua do Lago, 878 CEP 05508-080, Sao Paulo (Brazil)

    2007-09-15

    The search for efficient, auto-sustainable constructions that allows the user a contact with the outer environment has stimulated the development of advanced strategies, in various devices, for the exploitation of the daylight. A low cost data acquisition system was developed in this study, to observe the distribution of the natural light inside a prototype and to evaluate the quantitative performance for redirecting systems. The luminous sensor is a light dependent resistor, that responds to the illuminance with a reduction in the resistance when illuminated, through a log-log dependence. Calibration curves are set up to relate the change of resistance to absolute illuminance. It therefore provides a continuous investigation of the illuminance for various sampled points in the interior test space with a 0.03% digital error due to the 12-bit resolution. The final measured error of 5% is mainly due to the system calibration and resistance memory history. The circuit connects to a standard parallel port of any Personal Computer and supplies 64 analog inputs, one for each luminous sensor. The circuit can be easily modified to attend different quantities of analog inputs or communication ports. (author)

  19. Thermal and Daylighting Performance of Energy-Efficient Windows in Highly Glazed Residential Buildings: Case Study in Korea

    Directory of Open Access Journals (Sweden)

    Chang Heon Cheong

    2014-10-01

    Full Text Available Cooling load in highly glazed residential building can be excessively large due to uncontrolled solar energy entering the indoor space. This study focuses on the cooling load reduction and changes in the daylighting properties via the application of a double window system (DWS with shading with various surface reflectivities in highly glazed residential buildings. Evaluation of thermal and daylighting performances is carried out using simulation tools. The reductions in cooling load and energy cost through the use of DWS are evaluated through a comparative simulation considering conventional windows: a single window and a double window. Three variables of window types, natural ventilation, and shading reflectivity are reflected in the study. According to our results, implementation of DWS reduced cooling load by 43%–61%. Electricity cost during the cooling period was reduced by a maximum of 24%. However, a shading device setting that prioritizes effective cooling load reduction can greatly decrease the daylighting factor and luminance level of indoor space. A DWS implementing shading device with highly reflective at all surfaces is appropriate option for the more comfortable thermal and visual environment, while a shading device with low reflectivity at rear of the surface can contribute an additional 4% cooling load reduction.

  20. On the development of new SPMN diurnal video systems for daylight fireball monitoring

    Science.gov (United States)

    Madiedo, J. M.; Trigo-Rodríguez, J. M.; Castro-Tirado, A. J.

    2008-09-01

    Daylight fireball video monitoring High-sensitivity video devices are commonly used for the study of the activity of meteor streams during the night. These provide useful data for the determination, for instance, of radiant, orbital and photometric parameters ([1] to [7]). With this aim, during 2006 three automated video stations supported by Universidad de Huelva were set up in Andalusia within the framework of the SPanish Meteor Network (SPMN). These are endowed with 8-9 high sensitivity wide-field video cameras that achieve a meteor limiting magnitude of about +3. These stations have increased the coverage performed by the low-scan allsky CCD systems operated by the SPMN and, besides, achieve a time accuracy of about 0.01s for determining the appearance of meteor and fireball events. Despite of these nocturnal monitoring efforts, we realised the need of setting up stations for daylight fireball detection. Such effort was also motivated by the appearance of the two recent meteorite-dropping events of Villalbeto de la Peña [8,9] and Puerto Lápice [10]. Although the Villalbeto de la Peña event was casually videotaped, and photographed, no direct pictures or videos were obtained for the Puerto Lápice event. Consequently, in order to perform a continuous recording of daylight fireball events, we setup new automated systems based on CCD video cameras. However, the development of these video stations implies several issues with respect to nocturnal systems that must be properly solved in order to get an optimal operation. The first of these video stations, also supported by University of Huelva, has been setup in Sevilla (Andalusia) during May 2007. But, of course, fireball association is unequivocal only in those cases when two or more stations recorded the fireball, and when consequently the geocentric radiant is accurately determined. With this aim, a second diurnal video station is being setup in Andalusia in the facilities of Centro Internacional de Estudios y

  1. Daylighting for energy conservation in an existing building under tropical climate conditions: a case study of Lai Sue Thai building Ramkhamhaeng University

    Directory of Open Access Journals (Sweden)

    Lerdlekha Tanachaikhan

    2015-12-01

    Full Text Available Daylighting using skylight has been shown to have a high potential in reducing electrical lighting energy, and could provide a more pleasant atmosphere of a daylit space. However, in hot climates, the main constraint of daylighting is the solar heat gain that contributes to major heat load for an air-conditioning system. If the balance between the beneficial light gain used to offset lighting energy requirement and heat gain from daylight is well considered, significant energy savings can be obtained. The main objective of the study is to evaluate the potential of daylighting for energy conservation in the tropics through theoretical analysis (simulation study and experimental observation. Lai Sue Thai Building (an existing and educational building located at Ramkhamkaeng University was selected as a case study. From analysis, use of daylight could reduce electrical energy in this building by up to 76% compared to the initial condition where fully lighting was supplied. Window orientation would also play an important role. Moreover, heat gain through windows due to daylighting can be controlled by overhangs and the appropriate Window-to-Wall ratio that would be about 30% for this building. An experimental study was also carried out to validate the results in a selected room. About 49% and 37% of Relative Root Mean Square Error (RRMSE were observed in light and heat measurements, respectively

  2. Essence of Daylight in the Cistercian Monastic Church of S. Bento de Cástris, Évora, Portugal

    Science.gov (United States)

    Martins, Ana M. T.; Carlos, Jorge S.

    2017-10-01

    Natural light in the Cistercian churches is closely linked not only with the liturgical requirements at the “officium” but also with the canonical hours based on the "ora et labora" dictated by the Rule of St. Benedict. The Cistercian architecture, in its beginnings (12th century forward) is characterized by austerity, simplicity and the play of light and shadow that gives value to the monastic architectural space itself, making it perfect for a contemplative experience. In the Cistercian Monastery the church is the central piece of the monastic building. Nave, transept and apse are the main architectural components to which is added the choir. This paper contextualizes the importance and close connections of natural light, within the Cistercian Monasteries architecture. Thus the essence of daylight is analysed within the Church of the Monastery of S. Bento de Cástris, in Évora, Portugal. This former Monastery (13th - 19th centuries) includes the church, at the south-eastern corner which has not only a high choir, but also a low lateral choir (within the presbytery). Its unchanged exterior walls are made of solid masonry. Although the function of the walls is primarily structural, the windows allow the daylight to penetrate the space of the church. The church has two external façades facing northeast and southeast. The combined orientation effect of the church’s main axis and the sun trajectory determines how the sunlight reaches the interior of this architectural structure. This study presents the qualitative and quantitative analysis of the luminous environment in the church of S. Bento de Cástris, being the first based on the authors’ perception of the effect of the daylight within the different areas of the enclosed space. The appreciation of the spatial experiences was supported by quantitative daylight simulations that were conducted in selected areas within the space. With this paper is intended to contribute to the debate about the specificity

  3. The impact of daylight saving time on electricity consumption: Evidence from southern Norway and Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Mirza, Faisal Mehmood, E-mail: faisal.mirza@umb.no [Department of Economics and Resource Management, Norwegian University of Life Sciences (UMB), P.O. Box 5003, 1432 As (Norway); Bergland, Olvar, E-mail: olvar.bergland@umb.no [Department of Economics and Resource Management, Norwegian University of Life Sciences (UMB), P.O. Box 5003, 1432 As (Norway)

    2011-06-15

    This paper examines the impact of daylight saving time (DST) on electricity consumption in southern Norway and Sweden. As DST was implemented in both the countries in 1980, we do not have a clear counterfactual in the form of a control period to identify the impact of DST directly with before and after or with and without analysis. This problem in the study is resolved by using 'equivalent day normalization technique' to identify the impact of DST. The difference-in-difference (DID) average treatment effects model suggests an annual reduction of at least 1.0 percent in electricity consumption for both Norway and Sweden due to DST. The average annual electricity consumption reduction corresponding to DST effects equals 519 and 882 GWh for southern Norway and Sweden, resulting in an annual financial saving of 16.1 million Euros and 30.1 million Euros, respectively. The distribution of treatment effects across different hours of the day indicates a small but significant reduction in electricity consumption during the morning and a steep decline during the evening hours in both countries. - Highlights: > We assess the impact of DST on electricity consumption in southern Norway and Sweden. > DST reduces electricity consumption by 1.3 percent in both countries. > The impact is smaller during the morning hours but larger during evening hours. > Respective annual financial savings equal Euro 16.1 and 30.1 million for Norway and Sweden. > Average annual electricity savings equal 519 and 882 GWh for two countries, respectively.

  4. The impact of daylight saving time on electricity consumption: Evidence from southern Norway and Sweden

    International Nuclear Information System (INIS)

    Mirza, Faisal Mehmood; Bergland, Olvar

    2011-01-01

    This paper examines the impact of daylight saving time (DST) on electricity consumption in southern Norway and Sweden. As DST was implemented in both the countries in 1980, we do not have a clear counterfactual in the form of a control period to identify the impact of DST directly with before and after or with and without analysis. This problem in the study is resolved by using 'equivalent day normalization technique' to identify the impact of DST. The difference-in-difference (DID) average treatment effects model suggests an annual reduction of at least 1.0 percent in electricity consumption for both Norway and Sweden due to DST. The average annual electricity consumption reduction corresponding to DST effects equals 519 and 882 GWh for southern Norway and Sweden, resulting in an annual financial saving of 16.1 million Euros and 30.1 million Euros, respectively. The distribution of treatment effects across different hours of the day indicates a small but significant reduction in electricity consumption during the morning and a steep decline during the evening hours in both countries. - Highlights: → We assess the impact of DST on electricity consumption in southern Norway and Sweden. → DST reduces electricity consumption by 1.3 percent in both countries. → The impact is smaller during the morning hours but larger during evening hours. → Respective annual financial savings equal Euro 16.1 and 30.1 million for Norway and Sweden. → Average annual electricity savings equal 519 and 882 GWh for two countries, respectively.

  5. Incidence of myocardial infarction with shifts to and from daylight savings time.

    Science.gov (United States)

    Jiddou, Monica R; Pica, Mark; Boura, Judy; Qu, Lihua; Franklin, Barry A

    2013-03-01

    Modulators of normal bodily functions such as the duration and quality of sleep might transiently influence cardiovascular risk. The transition to daylight savings time (DST) has been associated with a short-term increased incidence ratio (IR) of acute myocardial infarction (AMI). The present retrospective study examined the IR of AMIs that presented to our hospitals the week after DST and after the autumn switch to standard time, October 2006 to April 2012, with specific reference to the AMI type. Our study population (n = 935 patients; 59% men, 41% women) was obtained from the electronic medical records of the Royal Oak and Troy campuses of the Beaumont Hospitals in Michigan. Overall, the frequency of AMI was similar in the spring and autumn, 463 (49.5%) and 472 (50.5%), respectively. The IR for the first week after the spring shift was 1.17 (95% confidence interval 1.00 to 1.36). After the transition from DST in the autumn, the IR for the same period was lower, but not significantly different, 0.99 (95% confidence interval 0.85 to 1.16). Nevertheless, the greatest increase in AMI occurred on the first day (Sunday) after the spring shift to DST (1.71, 95% confidence interval 1.09 to 2.02; p <0.05). Also, a significantly greater incidence was found of non-ST-segment myocardial infarction after the transition to DST in the study group compared with that in the control group (p = 0.022). In conclusion, these data suggest that shifts to and from DST might transiently affect the incidence and type of acute cardiac events, albeit modestly. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Quantifying the potential of automated dynamic solar shading in office buildings through integrated simulations of energy and daylight

    DEFF Research Database (Denmark)

    Nielsen, Martin Vraa; Svendsen, Svend; Bjerregaard Jensen, Lotte

    2011-01-01

    The façade design is and should be considered a central issue in the design of energy-efficient buildings. That is why dynamic façade components are increasingly used to adapt to both internal and external impacts, and to cope with a reduction in energy consumption and an increase in occupant...... them with various window heights and orientations. Their performance was evaluated on the basis of the building’s total energy demand, its energy demand for heating, cooling and lighting, and also its daylight factors. Simulation results comparing the three façade alternatives show potential...

  7. Influence of daylight on the fate of silver and zinc oxide nanoparticles in natural aquatic environments.

    Science.gov (United States)

    Odzak, Niksa; Kistler, David; Sigg, Laura

    2017-07-01

    Nanoparticles, such as silver (Ag-NP) and zinc oxide (ZnO-NP), are increasingly used in many consumer products. These nanoparticles (NPs) will likely be exposed to the aquatic environment (rain, river, lake water) and to light (visible and UV) in the products where they are applied, or after those products are discharged. Dissolution of Ag-NP and ZnO-NP is an important process because the dissolved Ag + and Zn 2+ are readily available and toxic for aquatic organisms. The objective of this study was to investigate the role of daylight (UV and visible) for the fate of engineered Ag-NP and ZnO-NPs in different types of natural waters. Ag-NP and ZnO-NP were exposed to rainwater, river Rhine, and lake waters (Greifen, Lucerne, Cristallina, Gruère) under different light conditions (no light, UV 300-400 nm and visible light 400-700 nm) for up to 8 days. Stronger agglomeration of Ag-NP was observed in the waters with higher ionic strength in comparison to those with lower ionic strength. Visible light tended to increase the dissolution of Ag-NP under most natural water conditions in comparison to dark conditions, whereas UV-light led to decreased dissolved Ag + after longer exposure time. These effects illustrate the dynamic interactions of Ag-NP with light, which may lead both to increased oxidation and to increased reduction of Ag + by organic compounds under UV-light. In the case of ZnO-NP, agglomeration occurred at higher ionic strength, but the effects of pH were predominant for dissolution, which occurred up to concentrations close to the solubility limit of ZnO(s) at pH around 8.2 and to nearly complete dissolution of ZnO-NP at lower pH (pH 4.8-6.5), with both visible and UV-light facilitating dissolution. This study thus shows that light conditions play an important role in the dissolution processes of nanoparticles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. MAL Daylight Photodynamic Therapy for Actinic Keratosis: Clinical and Imaging Evaluation by 3D Camera.

    Science.gov (United States)

    Cantisani, Carmen; Paolino, Giovanni; Pellacani, Giovanni; Didona, Dario; Scarno, Marco; Faina, Valentina; Gobello, Tommaso; Calvieri, Stefano

    2016-07-11

    Non-melanoma skin cancer is the most common skin cancer with an incidence that varies widely worldwide. Among them, actinic keratosis (AK), considered by some authors as in situ squamous cell carcinoma (SCC), are the most common and reflect an abnormal multistep skin cell development due to the chronic ultraviolet (UV) light exposure. No ideal treatment exists, but the potential risk of their development in a more invasive form requires prompt treatment. As patients usually present with multiple AK on fields of actinic damage, there is a need for effective, safe, simple and short treatments which allow the treatment of large areas. To achieve this, daylight photodynamic therapy (DL-PDT) is an innovative treatment for multiple mild actinic keratosis, well tolerated by patients. Patients allocated to the PDT unit, affected by multiple mild-moderate and severe actinic keratosis on sun-exposed areas treated with DL-PDT, were clinically evaluated at baseline and every three months with an Antera 3D, Miravex(©) camera. Clinical and 3D images were performed at each clinical check almost every three months. In this retrospective study, 331 patients (56.7% male, 43.3% female) were treated with DL-PDT. We observed a full clearance in more than two-thirds of patients with one or two treatments. Different responses depend on the number of lesions and on their severity; for patients with 1-3 lesions and with grade I or II AK, a full clearance was reached in 85% of cases with a maximum of two treatments. DL-PDT in general improved skin tone and erased sun damage. Evaluating each Antera 3D images, hemoglobin concentration and pigmentation, a skin color and tone improvement in 310 patients was observed. DL-PDT appears as a promising, effective, simple, tolerable and practical treatment for actinic damage associated with AK, and even treatment of large areas can be with little or no pain. The 3D imaging allowed for quantifying in real time the aesthetic benefits of DL

  9. Fatal accidents following changes in daylight savings time: the American experience.

    Science.gov (United States)

    Varughese; Allen

    2001-01-01

    Objective: This study examines specific hypotheses that both sleep loss and behavioral changes occurring with the time shifts for Daylight Savings Time (DST) significantly effect the number of fatal traffic accidents in the United States of America.Background: It has been reported that there is a significant increase in the number of automobile accidents in the spring shift to DST due to the loss of 1 h of sleep. But the extra hour gained at night with the shift from DST in the fall has been variably reported to be associated with increases and decreases in the number of automobile accidents which may reflect either behavioral anticipation with an extended late night prior to the change or the benefit of extra sleep after the change.Methods: Data from 21 years of United States' fatal automobile accidents were gathered. The mean number of accidents on the days at the time of the shifts (Saturday, Sunday and Monday) was compared to the average of the corresponding mean number of accidents on the matching day of the weeks preceding and following the shift. This was repeated for each DST shift. The number of accidents for a particular shift was also correlated with the year of the accidents.Results: There was a significant increase in accidents for the Monday immediately following the spring shift to DST (t=1.92, P=0.034). There was also a significant increase in number of accidents on the Sunday of the fall shift from DST (P<0.002). No significant changes were observed for the other days. A significant negative correlation with the year was found between the number of accidents on the Saturdays and Sundays but not Mondays.Conclusions: The sleep deprivation on the Monday following shift to DST in the spring results in a small increase in fatal accidents. The behavioral adaptation anticipating the longer day on Sunday of the shift from DST in the fall leads to an increased number of accidents suggesting an increase in late night (early Sunday morning) driving when

  10. MAL Daylight Photodynamic Therapy for Actinic Keratosis: Clinical and Imaging Evaluation by 3D Camera

    Directory of Open Access Journals (Sweden)

    Carmen Cantisani

    2016-07-01

    Full Text Available Non-melanoma skin cancer is the most common skin cancer with an incidence that varies widely worldwide. Among them, actinic keratosis (AK, considered by some authors as in situ squamous cell carcinoma (SCC, are the most common and reflect an abnormal multistep skin cell development due to the chronic ultraviolet (UV light exposure. No ideal treatment exists, but the potential risk of their development in a more invasive form requires prompt treatment. As patients usually present with multiple AK on fields of actinic damage, there is a need for effective, safe, simple and short treatments which allow the treatment of large areas. To achieve this, daylight photodynamic therapy (DL-PDT is an innovative treatment for multiple mild actinic keratosis, well tolerated by patients. Patients allocated to the PDT unit, affected by multiple mild−moderate and severe actinic keratosis on sun-exposed areas treated with DL-PDT, were clinically evaluated at baseline and every three months with an Antera 3D, Miravex© camera. Clinical and 3D images were performed at each clinical check almost every three months. In this retrospective study, 331 patients (56.7% male, 43.3% female were treated with DL-PDT. We observed a full clearance in more than two-thirds of patients with one or two treatments. Different responses depend on the number of lesions and on their severity; for patients with 1–3 lesions and with grade I or II AK, a full clearance was reached in 85% of cases with a maximum of two treatments. DL-PDT in general improved skin tone and erased sun damage. Evaluating each Antera 3D images, hemoglobin concentration and pigmentation, a skin color and tone improvement in 310 patients was observed. DL-PDT appears as a promising, effective, simple, tolerable and practical treatment for actinic damage associated with AK, and even treatment of large areas can be with little or no pain. The 3D imaging allowed for quantifying in real time the aesthetic benefits

  11. Proposal of the Tubular Daylight System Using Acrylonitrile Butadiene Styrene (ABS Metalized with Aluminum for Reflective Tube Structure

    Directory of Open Access Journals (Sweden)

    Anderson Diogo Spacek

    2018-01-01

    Full Text Available In the search for alternatives to reduce the consumption of electric energy, the possibility of using natural light for lighting through TDD (tubular daylight devices or TDGS (tubular daylight guidance systems appears. These natural luminaires are used in rooms where you want to save electricity and enjoy the benefits of natural light. The present work proposes the construction of a tubular system for the conduction of natural light that replaces aluminum with silver (currently marketed by several companies by polymer metallized with aluminum, offering a low cost. The polymer acrylonitrile butadiene styrene (ABS, coated with aluminum by physical vapor deposition (ionization, was evaluated for some tests to verify characteristics of the structure and the metallized surface. After the tests, the construction of the reflective tube was performed and validated in a real scale of application. The results proved the technical viability of the proposed tube construction for the realization of direct sunlight for illumination using polymeric material. Although it has produced 35% less than the reference tube, it can be marketed at an estimated cost of 50% less.

  12. The daylight saving time in Mexico; El cambio de horario durante la epoca del verano en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Covarrubias Ramos, Rogelio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    The daylight saving time in Mexico for energy saving is analyzed; such a change is made forwarding the clocks one hour in all Mexico the first Sunday of April and backing them an hour the last Sunday of October. Mention is made the reasons why Mexico adopted this measure, the social-economic impact that brings along and the benefits of this daylight saving time. The case of countries that also apply this measure is analyzed. It is expected that this measure attains benefits for the society either collectively or individually through the ecology and the economy. [Espanol] Se analiza el cambio de horario en la epoca de verano en Mexico para ahorrar energia; dicho cambio se realiza al adelantar una hora al reloj en todo el territorio de Mexico el primer domingo de abril y retrazarlo una hora el ultimo domingo de octubre. Se mencionan las razones por las cuales Mexico adopto esta medida, el impacto socio-economico que traera consigo y los beneficios del cambio de horario. Se aborda la situacion de los paises que tambien aplican esta medida. Se espera que esta medida logre beneficios para la sociedad, ya sea en modo colectivo o individual, para la ecologia y para la economia.

  13. Continuous daylight in the high-Arctic summer supports high plankton respiration rates compared to those supported in the dark

    KAUST Repository

    Mesa, Elena

    2017-04-21

    Plankton respiration rate is a major component of global CO2 production and is forecasted to increase rapidly in the Arctic with warming. Yet, existing assessments in the Arctic evaluated plankton respiration in the dark. Evidence that plankton respiration may be stimulated in the light is particularly relevant for the high Arctic where plankton communities experience continuous daylight in spring and summer. Here we demonstrate that plankton community respiration evaluated under the continuous daylight conditions present in situ, tends to be higher than that evaluated in the dark. The ratio between community respiration measured in the light (Rlight) and in the dark (Rdark) increased as the 2/3 power of Rlight so that the Rlight:Rdark ratio increased from an average value of 1.37 at the median Rlight measured here (3.62 µmol O2 L-1 d-1) to an average value of 17.56 at the highest Rlight measured here (15.8 µmol O2 L-1 d-1). The role of respiratory processes as a source of CO2 in the Arctic has, therefore, been underestimated and is far more important than previously believed, particularly in the late spring, with 24 h photoperiods, when community respiration rates are highest.

  14. The daylight saving time in Mexico; El cambio de horario durante la epoca del verano en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Covarrubias Ramos, Rogelio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    The daylight saving time in Mexico for energy saving is analyzed; such a change is made forwarding the clocks one hour in all Mexico the first Sunday of April and backing them an hour the last Sunday of October. Mention is made the reasons why Mexico adopted this measure, the social-economic impact that brings along and the benefits of this daylight saving time. The case of countries that also apply this measure is analyzed. It is expected that this measure attains benefits for the society either collectively or individually through the ecology and the economy. [Espanol] Se analiza el cambio de horario en la epoca de verano en Mexico para ahorrar energia; dicho cambio se realiza al adelantar una hora al reloj en todo el territorio de Mexico el primer domingo de abril y retrazarlo una hora el ultimo domingo de octubre. Se mencionan las razones por las cuales Mexico adopto esta medida, el impacto socio-economico que traera consigo y los beneficios del cambio de horario. Se aborda la situacion de los paises que tambien aplican esta medida. Se espera que esta medida logre beneficios para la sociedad, ya sea en modo colectivo o individual, para la ecologia y para la economia.

  15. Spanish-Portuguese consensus statement on use of daylight-mediated photodynamic therapy with methyl aminolevulinate in the treatment of actinic keratosis.

    Science.gov (United States)

    Gilaberte, Y; Aguilar, M; Almagro, M; Correia, O; Guillén, C; Harto, A; Pérez-García, B; Pérez-Pérez, L; Redondo, P; Sánchez-Carpintero, I; Serra-Guillén, C; Valladares, L M

    2015-10-01

    Daylight-mediated photodynamic therapy (PDT) is a new type of PDT that is as effective as conventional PDT in grade 1 and 2 actinic keratosis but with fewer adverse effects, resulting in greater efficiency. The climatic conditions in the Iberian Peninsula require an appropriately adapted consensus protocol. We describe a protocol for the treatment of grade 1 and 2 actinic keratosis with daylight-mediated PDT and methyl aminolevulinate (MAL) adapted to the epidemiological and clinical characteristics of Spanish and Portuguese patients and the climatic conditions of both countries. Twelve dermatologists from different parts of Spain and Portugal with experience in the treatment of actinic keratosis with PDT convened to draft a consensus statement for daylight-mediated PDT with MAL in these countries. Based on a literature review and their own clinical experience, the group developed a recommended protocol. According to the recommendations adopted, patients with multiple grade 1 and 2 lesions, particularly those at risk of developing cancer, are candidates for this type of therapy. Daylight-mediated PDT can be administered throughout the year, although it is not indicated at temperatures below 10°C or at excessively high temperatures. Likewise, therapy should not be administered when it is raining, snowing, or foggy. The procedure is simple, requiring application of a sunscreen with a protection factor of at least 30 based exclusively on organic filters, appropriate preparation of the lesions, application of MAL without occlusion, and activation in daylight for 2hours. This consensus statement represents a practical and detailed guideline to achieve maximum effectiveness of daylight-mediated PDT with MAL in Spain and Portugal with minimal adverse effects. Copyright © 2015 Elsevier España, S.L.U. and AEDV. All rights reserved.

  16. The effect of dynamic solar shading on energy, daylighting and thermal comfort in a nearly zero-energy loft room in Rome and Copenhagen

    DEFF Research Database (Denmark)

    Skarning, Gunnlaug Cecilie Jensen; Hviid, Christian Anker; Svendsen, Svend

    2017-01-01

    alternatives in buildings with very low space-heating demand, this study mapped and compared energy, daylighting and thermal comfort for various combinations of window size and glazing properties, with and without dynamic shading. The study considered a loft room with sloped roof windows and moderate venting...... as defined by the Adaptive Thermal Comfort (ATC) model....... options in nearly zero-energy homes in Rome and Copenhagen. The more flexible solution space with dynamic shading made it possible to either reduce the time with operative temperatures exceeding the comfort limit by 40–50 h or increase daylighting by 750–1000 h more than could be achieved without shading...

  17. Balancing the daylighting and energy performance of solar screens in residential desert buildings: Examination of screen axial rotation and opening aspect ratio

    KAUST Repository

    Sabry, Hanan

    2014-05-01

    Solar screens are typically used to control solar access into building spaces. They proved their usefulness in improving the daylighting and energy performance of buildings in the hot arid desert environments which are endowed with abundance of clear skies.The daylighting and energy performance of solar screens is affected by many parameters. These include screen perforation, depth, reflectivity and color, aspect ratio of openings, shape, tilt angle and rotation. Changing some of these parameters can improve the daylighting performance drastically. However, this can result in increased energy consumption. A balanced solution must be sought, where acceptable daylighting performance would be achieved at minimum energy consumption.This paper aims at defining solar screen designs that achieve visual comfort and at the same time minimum energy consumption in residential desert settings. The study focused on the effect of changing the solar screen axial rotation and the aspect ratio of its openings under the desert clear-sky. The individual and combined effects of changing these parameters were studied.Results of this study demonstrated that a non-rotated solar screen that has wide horizontal openings (aspect ratio of 18:1) proved to be successful in the north and south orientations. Its performance in the east/west orientations was also superior. In contrast, the screen that was rotated along its vertical axis while having small size openings (aspect ratio of 1:1) proved to be more successful in the east/west orientations. Its performance in the north orientation was also good. These solutions enhanced daylighting performance, while maintaining the energy consumption at a minimum.Moreover, it was observed that combining two screen parameters which proved useful in previous studies on daylighting or thermal performance does not add up to better solutions. The combined solutions that were tested in this study did not prove successful in satisfying daylighting and thermal

  18. Continuous activation of PpIX by daylight is as effective as and less painful than conventional photodynamic therapy for actinic keratoses; a randomized, controlled, single-blinded study

    DEFF Research Database (Denmark)

    Wiegell, S.R.; Hædersdal, Merete; Philipsen, P.A.

    2008-01-01

    of the face and scalp were treated with MAL-PDT in two symmetrical areas. One area was illuminated by red LED light (37 J cm(-2)) after 3-h incubation with MAL under occlusive dressing. The other area was treated with daylight for 2.5 h after the MAL cream had been under occlusion for half an hour. Results We...... found no significant difference in the treatment effect between the two treatments (P = 0.13), with a reduction of AK lesions of 79% in the daylight area compared with 71% in the LED area. Treatment response in the daylight area did not depend on the intensity of the daylight. Illumination with LED...... of porphyrins during its formation. Objectives The objective of this randomized controlled study was to compare response rates and adverse effects after methyl aminolevulinate (MAL)-PDT using conventional red light-emitting diode (LED) light vs. daylight. Patients/methods Twenty-nine patients with AK...

  19. Effects of accelerated artificial daylight aging on bending strength and bonding of glass fibers in fiber-embedded maxillofacial silicone prostheses.

    Science.gov (United States)

    Hatamleh, Muhanad M; Watts, David C

    2010-07-01

    The purpose of this study was to test the effect of different periods of accelerated artificial daylight aging on bond strength of glass fiber bundles embedded into maxillofacial silicone elastomer and on bending strength of the glass fiber bundles. Forty specimens were fabricated by embedding resin-impregnated fiber bundles (1.5-mm diameter, 20-mm long) into maxillofacial silicone elastomer. Specimens were randomly allocated into four groups, and each group was subjected to different periods of accelerated daylight aging as follows (in hours); 0, 200, 400, and 600. The aging cycle included continuous exposure to quartz-filtered visible daylight (irradiance 760 W/m(2)) under an alternating weathering cycle (wet for 18 minutes, dry for 102 minutes). Pull-out tests were performed to evaluate bond strength between fiber bundles and silicone using a universal testing machine at 1 mm/min crosshead speed. Also a three-point bending test was performed to evaluate bending strength of the fiber bundles. One-way ANOVA and Bonferroni post hoc tests were carried out to detect statistical significance (p aging only. After 200 hours of exposure to artificial daylight and moisture conditions, bond strength between glass fibers and heat-cured silicones is optimal, and the bending strength of the glass fiber bundles is enhanced.

  20. Impact of windows and daylight exposure on overall health and sleep quality of office workers: a case-control pilot study.

    Science.gov (United States)

    Boubekri, Mohamed; Cheung, Ivy N; Reid, Kathryn J; Wang, Chia-Hui; Zee, Phyllis C

    2014-06-15

    This research examined the impact of daylight exposure on the health of office workers from the perspective of subjective well-being and sleep quality as well as actigraphy measures of light exposure, activity, and sleep-wake patterns. Participants (N = 49) included 27 workers working in windowless environments and 22 comparable workers in workplaces with significantly more daylight. Windowless environment is defined as one without any windows or one where workstations were far away from windows and without any exposure to daylight. Well-being of the office workers was measured by Short Form-36 (SF-36), while sleep quality was measured by Pittsburgh Sleep Quality Index (PSQI). In addition, a subset of participants (N = 21; 10 workers in windowless environments and 11 workers in workplaces with windows) had actigraphy recordings to measure light exposure, activity, and sleep-wake patterns. Workers in windowless environments reported poorer scores than their counterparts on two SF-36 dimensions--role limitation due to physical problems and vitality--as well as poorer overall sleep quality from the global PSQI score and the sleep disturbances component of the PSQI. Compared to the group without windows, workers with windows at the workplace had more light exposure during the workweek, a trend toward more physical activity, and longer sleep duration as measured by actigraphy. We suggest that architectural design of office environments should place more emphasis on sufficient daylight exposure of the workers in order to promote office workers' health and well-being.

  1. Continuous ultra-low-intensity artificial daylight is not as effective as red LED light in photodynamic therapy of multiple actinic keratoses

    DEFF Research Database (Denmark)

    Wiegell, Stine Regin; Heydenreich, Jakob; Fabricius, Susanne

    2011-01-01

    Daylight-mediated photodynamic therapy (PDT) is a simple and tolerable treatment of nonmelanoma skin cancer. It is of interest which light intensity is sufficient to prevent accumulation of protoporphyrin IX (PpIX) and effectively treat actinic keratoses (AKs). We compared the efficacy of PDT...

  2. Daylight-saving time: Consumption and demand saving and pollutants emission reduction; El cambio de horario de verano: Ahorros en consumo y demanda, y reduccion de contaminantes

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Gaudencio; Diaz, Rodrigo; Fiscal, Raul; Alquicira, Claudia; Martinez, Serafin; Maqueda, Martin [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    This paper presents some of the saving obtained in demand and in fuels with the daylight-saving time, as well as the main aspects considered to make an evaluation of it. [Espanol] Se presentan los ahorros obtenidos en consumo, demanda y combustibles con el cambio de horario de verano, asi como los principales aspectos considerados para efectuar la evaluacion de los mismos.

  3. Combination of ablative fractional laser and daylight-mediated photodynamic therapy for actinic keratosis in organ transplant recipients – a randomized controlled trial

    DEFF Research Database (Denmark)

    Togsverd-Bo, Katrine; Lei, Ulrikke; Erlendsson, A M

    2015-01-01

    BACKGROUND: Topical photodynamic therapy (PDT) for actinic keratoses (AK) is hampered by pain during illumination and inferior efficacy in organ-transplant recipients (OTR). OBJECTIVES: We assessed ablative fractional laser (AFL)-assisted daylight photodynamic therapy (PDT) (AFL-dPDT) compared...

  4. Photodynamic therapy of actinic keratoses with 8% and 16% methyl aminolaevulinate and home-based daylight exposure: a double-blinded randomized clinical trial

    DEFF Research Database (Denmark)

    Wiegell, S.R.; Haedersdal, M.; Eriksen, P.

    2009-01-01

    Background Photodynamic therapy (PDT) is an effective but time-consuming and often painful treatment for actinic keratosis (AK). Home-based daylight-PDT has the potential to facilitate treatment procedure and to reduce associated pain due to continuous activation of small amounts of porphyrins...

  5. Daylight photodynamic therapy with methyl aminolevulinate cream as a convenient, similarly effective, nearly painless alternative to conventional photodynamic therapy in actinic keratosis treatment

    DEFF Research Database (Denmark)

    Rubel, D M; Spelman, L; Murrell, D F

    2014-01-01

    BACKGROUND: Daylight photodynamic therapy (DL-PDT) of actinic keratosis (AK) has shown preliminary efficacy and safety results comparable to conventional photodynamic therapy (c-PDT), using methyl aminolevulinate (MAL) cream. OBJECTIVES: To demonstrate the efficacy and safety of DL-PDT vs. c...

  6. A statistical analysis of the energy policy act of 2005, its changes to the daylight saving program, and impact on residential energy consumption

    Science.gov (United States)

    Murray, Patrick L.

    Government programs designed to decrease resource consumption, improve productivity and capitalize on extended daylight hours in the summer have been developed and implemented throughout the world for nearly three hundred years. In 2005, The United States government adopted an extended daylight savings program that increases the number of weeks where the country observes Daylight Saving Time (DST) from 31 to 35 weeks. The program took effect in March 2007. Arguments in support of DST programs highlight the portion of electricity consumption attributed to residential lighting in the evening hours. Adjusting clocks forward by one hour in summer months is believed to reduce electricity consumption due to lighting and therefore significantly reduce residential energy consumption during the period of DST. This paper evaluates the efficacy of the changes to DST resulting from the Energy Policy Act of 2005. The study focuses on changes to household electricity consumption during the extended four weeks of DST. Arizona, one of two states that continue to opt out of DST serves as the study's control for a comparison with neighboring states, Colorado, Nebraska, Nevada, New Mexico, Oklahoma, Texas and Utah. Results from the regression analysis of a Difference in Difference model indicate that contrary to evaluations by Congress and the Department of Energy, the four week period of Extended Daylight Saving Time does not produce a significant decrease in per capita electricity consumption in Southwestern states.

  7. Daylight-saving time: Consumption and demand saving and pollutants emission reduction; El cambio de horario de verano: Ahorros en consumo y demanda, y reduccion de contaminantes

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Gaudencio; Diaz, Rodrigo; Fiscal, Raul; Alquicira, Claudia; Martinez, Serafin; Maqueda, Martin [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    This paper presents some of the saving obtained in demand and in fuels with the daylight-saving time, as well as the main aspects considered to make an evaluation of it. [Espanol] Se presentan los ahorros obtenidos en consumo, demanda y combustibles con el cambio de horario de verano, asi como los principales aspectos considerados para efectuar la evaluacion de los mismos.

  8. Demonstration with Energy and Daylighting Assessment of Sunlight Responsive Thermochromic (SRT) Window Systems

    Energy Technology Data Exchange (ETDEWEB)

    Broekhuis, Michael; Liposcak, Curtis; Witte, Michael; Henninger, Robert; Zhou, Xiaohui; Petzen, George; Buchanan, Michael; Kumar, Sneh

    2012-03-31

    Pleotint, LLC was able to successfully extrude thermochromic interlayer for use in the fenestration industry. Pleotint has developed a thermochromic sytem that requires two thermochromic colors to make a neutral color when in the tinted state. These two colors were assembled into a single interlayer called a tri-layer prelam by Crown Operations for use in the glass lamination industry. Various locations, orientations, and constructions of thermochromic windows were studied with funds from this contract. Locations included Australia, California, Costa Rica, Indiana, Iowa, Mexico. Installed orientations included vertical and skylight glazing applications. Various constructions included monolithic, double pane, triple pane constructions. A daylighting study was conducted at LinEl Signature. LinEl Signature has a conference room with a sylight roof system that has a west orientation. The existing LinEl Signature conference room had constant tint 40% VLT transparent skylights. Irradiance meters were installed on the interior and exterior sides of a constant tint skylight. After a month and a half of data collection, the irradiance meters were removed and the constant tint skylights were replaced with Pleotint thermochromic skylight windows. The irradiance meters were reinstalled in the same locations and irradiance data was collected. Both data sets were compared. The data showed that there was a linear relationship with exterior and interior irradiance for the existing constant tint skylights. The thermochromic skylights have a non-linear relationship. The thermochromic skylights were able to limit the amount of irradiance that passed through the thermochromic skylight. A second study of the LinEl Signature conference was performed using EnergyPlus to calculate the amount of Illuminance that passed through constant tint skylights as compared to thermochromic skylights. The constant tint skylights transmitted Illuminance is 2.8 times higher than the thermochromic

  9. A study on the performance enhancement of low-temperature solar applications : Daylighting and Adsorption Desalination System

    International Nuclear Information System (INIS)

    Kim, Yeong Min

    2011-02-01

    Thermal applications of solar energy are categorized by low, medium and high temperature. The present study has explored two major applications of solar energy widely researched and practiced these days. Of these, one deals with the utilization of solar energy for lighting in buildings, which is responsible for a great portion of electricity consumption, especially, for office and public buildings. Rapid improvements in lighting technology harnessing solar energy (daylight) have greatly contributed to radically reduce its consumption levels - and thereby reduce CO 2 emissions and cost. The other case considered here for solar utilization is so-called solar desalination using adsorbents (silica gels). This technology utilizes a silica gel adsorbent (desiccant) as a medium between an evaporator and a condenser to reject and facilitate latent heat of vaporization. Vapour is adsorbed and desorbed between evaporation and condensation phases. 1. Daylighting simulation A lighting upgrade is an obvious step toward improving a building's energy consumption, which could be easily assessed by using computer simulations. The present study has carried out a series of computer simulations for a lightless space as well as an actual classroom (in Jeju National University) when sun pipe systems are installed. They were first modeled by ECOTECT before RADIANCE was called in to conduct lighting analysis. Simulations were performed for equinoxes and solstices when the sun is at its highest altitude, i.e. at noon (12 PM). A lightless space and classroom of the same dimensions revealed the effectiveness of sun pipe systems to improve indoor lighting conditions throughout the year. 2. Development of adsorption desalination system utilizing silica-gel Some major components of an adsorption desalination system were designed and fabricated to assess its desalination efficiency when packs of silica-gel were used at different operating conditions. The amount of fresh water yield was studied

  10. A study on the performance enhancement of low-temperature solar applications : Daylighting and Adsorption Desalination System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeong Min

    2011-02-15

    Thermal applications of solar energy are categorized by low, medium and high temperature. The present study has explored two major applications of solar energy widely researched and practiced these days. Of these, one deals with the utilization of solar energy for lighting in buildings, which is responsible for a great portion of electricity consumption, especially, for office and public buildings. Rapid improvements in lighting technology harnessing solar energy (daylight) have greatly contributed to radically reduce its consumption levels - and thereby reduce CO{sub 2} emissions and cost. The other case considered here for solar utilization is so-called solar desalination using adsorbents (silica gels). This technology utilizes a silica gel adsorbent (desiccant) as a medium between an evaporator and a condenser to reject and facilitate latent heat of vaporization. Vapour is adsorbed and desorbed between evaporation and condensation phases. 1. Daylighting simulation A lighting upgrade is an obvious step toward improving a building's energy consumption, which could be easily assessed by using computer simulations. The present study has carried out a series of computer simulations for a lightless space as well as an actual classroom (in Jeju National University) when sun pipe systems are installed. They were first modeled by ECOTECT before RADIANCE was called in to conduct lighting analysis. Simulations were performed for equinoxes and solstices when the sun is at its highest altitude, i.e. at noon (12 PM). A lightless space and classroom of the same dimensions revealed the effectiveness of sun pipe systems to improve indoor lighting conditions throughout the year. 2. Development of adsorption desalination system utilizing silica-gel Some major components of an adsorption desalination system were designed and fabricated to assess its desalination efficiency when packs of silica-gel were used at different operating conditions. The amount of fresh water yield was

  11. A modified model for estimation of daylight factor for skylight integrated with dome roof structure of mud-house in New Delhi (India)

    Energy Technology Data Exchange (ETDEWEB)

    Chel, Arvind; Tiwari, G.N.; Singh, H.N. [Centre for Energy Studies (CES), Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110 016 (India)

    2010-10-15

    The daylight factor model given by Charted Institute of Building Services Engineers (CIBSE) was modified in this paper to incorporate time variations with respect to zenith angle ({theta}{sub z}) and vertical height (h) of working surface above ground surface which was normalized with central height (H) of skylight dome. The modified model contains constant exponents which are determined using linear regression analysis based on hourly experimental data of inside and outside illuminance for each month of the year 2007-2008. The prediction of modified model is found in good agreement with experimental observed inside illuminance data on the basis of values of root mean square percentage error (e) and correlation coefficient (r). The annual average daylight factor values for big and small dome skylight rooms are determined as 2.3% and 4.4% respectively. The energy saving potential of skylight rooms for selected climatic locations in India is also presented in this paper. (author)

  12. Workshop - Solar cells and daylight. Solar cell house. House building with integrated solar cell systems; Workshop - Solceller og dagslys. Solcellehus. Boligbyggeri med integrerede solcelleanlaeg

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Mio; Hansen, Ellen Kathrine

    2005-04-15

    The workshop 'Solar cells and daylight' at Aarhus School of Architecture aimed at studying and developing architectural potentials of integrating solar cell systems in building components for future house building. The aim of the process was to stress that technical conditions such as energy technological component design might work as central points of support in the future shaping and organisation of qualitative and functional design of houses. (BA)

  13. Daylight photocatalysis performance of biomorphic CeO2 hollow fibers prepared with lens cleaning paper as biotemplate

    International Nuclear Information System (INIS)

    Qian, Junchao; Chen, Feng; Wang, Fang; Zhao, Xiaobing; Chen, Zhigang

    2012-01-01

    Highlights: ► A novel, simple and eco-friendly approach for hierarchical, biomorphic CeO 2 hollow fibers with mesoporous tube walls is presented by using paper as template. ► The biomorphic CeO 2 fibers was composed of nanosheets with bimodal pore-size mesoporous distribution and exhibited high light-harvesting under sunlight irradiation. ► The CeO 2 microfibers biomimicking the natural plant structures have promising application for photodegradation of organic pollutants in water. -- Abstract: Hierarchical, biomorphic CeO 2 hollow fibers with mesoporous tube walls have been fabricated using lens cleaning paper as biotemplates. After sintered at 550 °C in air, the cellulosic fibers of paper were converted into micro-tubes composing of CeO 2 crystallites with grain size about 8 nm. The photocatalytic activity of the CeO 2 fibers was evaluated by photodegradation efficiency of methylene blue in aqueous solution under daylight irradiation. The characterized results show that the CeO 2 fibers faithfully replicated micro-fibrous structure derived from original template and possessed dramatic enhanced photocatalytic activity compared with bulk CeO 2 . This simple biotemplate method provides a cost-effective and eco-friendly route to obtain high performance photocatalysts.

  14. Daylight methyl-aminolevulinate photodynamic therapy versus ingenol mebutate for the treatment of actinic keratoses: an intraindividual comparative analysis.

    Science.gov (United States)

    Genovese, Giovanni; Fai, Dario; Fai, Carlotta; Mavilia, Luciano; Mercuri, Santo R

    2016-05-01

    Daylight-photodynamic therapy (D-PDT) and ingenol mebutate (IM) are novel therapies directed to actinic keratoses (AK). The purpose of our study was to compare effectiveness, tolerability, cosmetic outcome and patient preference of D-PDT versus IM in the treatment of grade I and II AK. Twenty-seven patients with AK on the face or scalp were enrolled. Each patient received, in a 25 cm(2) target area, D-PDT on right side and IM on left side. Overall 323 AK were treated. Both target areas achieved complete response in 40.47% of the cases and average AK clearance rate was similar for D-PDT and IM (p=0.74). In D-PDT areas mean grade II AK clearance rate was lower compared with that of grade I AK (p=0.015). In IM areas grade I and II AK average clearance rates were similar (p=0.28). At week 1 and month 1, mean local skin responses (LSR) score were higher in areas treated with IM. IM areas showed more severe pain and cosmetic sequelae. D-PDT had similar effectiveness to IM, even if IM demonstrated higher grade II AK clearance rate. Tolerability profile was superior for D-PDT in terms of LSR and pain. D-PDT was more cosmetically acceptable. Patients preferred D-PDT to IM in most cases. © 2016 Wiley Periodicals, Inc.

  15. Daylight photocatalysis performance of biomorphic CeO{sub 2} hollow fibers prepared with lens cleaning paper as biotemplate

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Junchao; Chen, Feng [Department of Material Science and Engineering, Jiangsu University, 212013 Zhenjiang (China); Wang, Fang; Zhao, Xiaobing [Department of Materials Science and Engineering, Changzhou University, 213164 Changzhou (China); Chen, Zhigang, E-mail: ziyou1900@gmail.com [Department of Material Science and Engineering, Jiangsu University, 212013 Zhenjiang (China); Jiangsu Key Laboratory for Environment Functional Materials, 215009 Suzhou University of Science and Technology, Suzhou (China); State Key laboratory of Crystal Material, Shandong University, 250100 Jinan (China)

    2012-08-15

    Highlights: ► A novel, simple and eco-friendly approach for hierarchical, biomorphic CeO{sub 2} hollow fibers with mesoporous tube walls is presented by using paper as template. ► The biomorphic CeO{sub 2} fibers was composed of nanosheets with bimodal pore-size mesoporous distribution and exhibited high light-harvesting under sunlight irradiation. ► The CeO{sub 2} microfibers biomimicking the natural plant structures have promising application for photodegradation of organic pollutants in water. -- Abstract: Hierarchical, biomorphic CeO{sub 2} hollow fibers with mesoporous tube walls have been fabricated using lens cleaning paper as biotemplates. After sintered at 550 °C in air, the cellulosic fibers of paper were converted into micro-tubes composing of CeO{sub 2} crystallites with grain size about 8 nm. The photocatalytic activity of the CeO{sub 2} fibers was evaluated by photodegradation efficiency of methylene blue in aqueous solution under daylight irradiation. The characterized results show that the CeO{sub 2} fibers faithfully replicated micro-fibrous structure derived from original template and possessed dramatic enhanced photocatalytic activity compared with bulk CeO{sub 2}. This simple biotemplate method provides a cost-effective and eco-friendly route to obtain high performance photocatalysts.

  16. Rapid microwave-assisted nonaqueous synthesis and growth mechanism of AgCl/Ag, and its daylight-driven plasmonic photocatalysis.

    Science.gov (United States)

    Jiang, Jing; Zhang, Lizhi

    2011-03-21

    We report on a rapid microwave-assisted nonaqueous synthesis and the growth mechanism of AgCl/Ag with controlled size and shape. By rationally varying the reaction temperature and the microwave irradiation time, we achieved the transformation of nanocubes to rounded triangular pyramids by a combined process of "oriented attachment" and Ostwald ripening. The surface plasmon resonance (SPR) properties of the as-prepared AgCl/Ag have been found to be somewhat dependent on the size, morphology, and composition. The as-prepared AgCl/Ag exhibits high photocatalytic activity and good reusability for decomposing organic pollutants (such as methyl orange (MO), rhodamine B (RhB), and pentachlorophenol (PCP)) under indoor artificial daylight illumination (ca. 1 mW cm(-2)). The AgCl/Ag has also been found to display a superior ability to harvest diffuse indoor daylight (ca. 5 mW cm(-2)), and could complete the degradation of 10 mg  L(-1) MO within 15 min. Experiments involving the trapping of active species have shown that the photocatalytic degradation of organic pollutants in the AgCl/Ag system may proceed through direct hole transfer. This study has revealed that plasmonic daylight photocatalysis may open a new frontier for indoor pollutant control around the clock under fluorescent lamp illumination. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Assessment of building facade performance in terms of daylighting and the associated energy consumption in architectural spaces: Vertical and horizontal shading devices for southern exposure facades

    Energy Technology Data Exchange (ETDEWEB)

    Alzoubi, Hussain H.; Al-Zoubi, Amneh H. [Department of Architecture, Jordan University of Science and Technology, Irbid 22110 (Jordan)

    2010-08-15

    This paper examines the effect of vertical and horizontal shading devices on the quality of daylight in buildings and the associated energy saving. Excessive daylight in architectural spaces contributes negatively to the energy consumption in buildings. Blinds and shading devices are good solutions to attenuate the surplus amount of daylight in spaces. Accordingly, this study evaluates the effect of shading devices on the amount of light flux and the associated solar energy in buildings. It estimates the energy consumption attributed to lighting spaces for three common positions of shading devices. Computer simulation strategy was undertaken to correlate the illuminance level in spaces with room geometry and architectural shading elements. The Holophane model for lighting calculations was used to estimate the average illuminance level on workplane and correlate it with the expected saving energy in buildings. The study concluded that there is an optimal orientation for shading devices that keeps the internal illuminance level within the acceptable range with minimum amount of solar heat gain. (author)

  18. Effect of internal woven roller shade and glazing on the energy and daylighting performances of an office building in the cold climate of Shillong

    International Nuclear Information System (INIS)

    Singh, Ramkishore; Lazarus, I.J.; Kishore, V.V.N.

    2015-01-01

    Highlights: • We simulated a number of glazing and interior roller shade alternatives. • Office room has been simulated for three window-to-wall ratios in a cold climate. • Daylighting and energy performances have been assessed for each alternative. • Maximum energy savings have been estimated in the office with a 30% glazed area. • Energy saving decreases for larger glazed area and fabric transmittance. - Abstract: The energy and visual performances of the façades are defined by many parameters including façade size, properties of glazings and shadings, and their arrangements as well as control strategies. In this study, a number of combinations of internal woven roller shades and four double glazings have been proposed and assessed in integrated manner in order to improve the energy efficiency and visual comfort in new or existing office buildings. Office rooms facing south, east, north and west have been simulated for cold climate, by varying glazed areas and proposed glazing and shading alternatives. Results have been calculated, compared and analyzed in terms of the energy consumptions, energy saving potentials, daylight autonomy, useful daylight illuminance and discomfort glare free time, for each of the combinations. Simulation results show that the choice of glazing and shading alternatives can have substantial impact on energy and visual performances of the office space. Regardless of façade orientation, the maximum energy saving is achieved for a window-to-wall ratio (WWR) of 30%. Saving potential decreases significantly for larger glazed area and for each façade orientation. For all façade orientations and glazed areas (except for 30% WWR in the north wall), a bare low-e coated double glazing (U = 1.616 W/m"2 K, SHGC = 0.209, τ_v = 0.301) is found to be the most energy efficient choice. For 30% north glazing, the energy efficiency can be maximized with a different bare low-e coated double glazing (U = 1.628 W/m"2 K, SHGC = 0.370, τ_v = 0

  19. Year-round daylight saving time will save more energy in India than corresponding DST or time zones

    International Nuclear Information System (INIS)

    Ahuja, Dilip R.; SenGupta, D.P.

    2012-01-01

    Many countries have experimented with daylight saving time (DST) to save energy and to align human activities more closely to the daily cycle of light and darkness. Using a novel methodology, we estimate the year-round energy savings to be obtained from advancing Indian Standard Time (IST), from the introduction of DST, and from dividing the country into two time zones. We find that the option of advancing IST consistently saves more energy than the corresponding DST option, which in turn saves more energy than the corresponding time zones option. This is because the energy benefits of advancing IST accrue for the entire year throughout the country, whereas the benefits of DST are confined to summer months and the benefits of two time zones are largely in the lower energy consuming eastern region. We recommend advancing IST by half-hour to being six hours ahead of UTC. This confers the advantages of DST and time zones without their disadvantages and is forecast to save more than 2 billion kWh of electricity every year during evening peaks that are difficult to supply. While these results are India-specific, similar exercises would be useful to many other countries. - Highlights: ► Advancing IST (YRDST) consistently saves more energy than the corresponding DST. ► DST consistently saves more energy than dividing India into two time zones. ► There are also many non-energy benefits of advancing IST. ► Results are for India; countries with DST may find it useful to consider YRDST.

  20. Organic Light-Emitting Diode with Color Tunable between Bluish-White Daylight and Orange-White Dusk Hue

    Directory of Open Access Journals (Sweden)

    Shih-Yun Liao

    2014-01-01

    Full Text Available The varying color of sunlight diurnally exhibits an important effect on circadian rhythm of living organisms. The bluish-white daylight that is suitable for work shows a color temperature as high as 9,000 K, while the homey orange-white dusk hue is as low as 2,000 K. We demonstrate in this report the feasibility of using organic light-emitting diode (OLED technology to fabricate sunlight-style illumination with a very wide color temperature range. The color temperature can be tuned from 2,300 K to 9,300 K, for example, by changing the applied voltage from 3 to 11 V for the device composing red and yellow emitters in the first emissive layer and blue emitter in the second. Unlike the prior arts, the color-temperature span can be made much wider without any additional carrier modulation layer, which should enable a more cost effective fabrication. For example, the color-temperature span is 7,000 K for the above case, while it is 1,700 K upon the incorporation of a nanoscale hole modulation layer in between the two emissive layers. The reason why the present device can effectively regulate the shifting of recombination zone is because the first emissive layer itself possesses an effective hole modulation barrier of 0.2 eV. This also explains why the incorporation of an extra hole modulation layer with a 0.7 eV barrier did not help extend the desirable color-temperature span since excessive holes may be blocked.

  1. Sustainable building with closed cavity facades. Top energy efficiency and more daylight; Nachhaltig bauen mit Closed Cavity Fassaden. Hoechste Energieeffizienz und mehr Tageslicht

    Energy Technology Data Exchange (ETDEWEB)

    Rudolf, Bernhard

    2012-08-15

    Facades have a key function within the sustainable construction since the energy conservation significantly depends on the building envelope. Beside an enhanced energy efficiency, the Green Building shall offer an improved utilization of day-lighting and comfortable indoor climatic conditions. Here, the innovative Closed Cavity Facade new standards. The former 'Poseidon building' in Frankfurt/Main (Federal Republic of Germany) and the multi-storey building of the Roche company in Basel (Switzerland) are equipped with this facade. The energy costs, operational costs as well as the maintenance costs are reduced sustainably using this closed bivalved facade.

  2. Daylight Redirecting Window Films

    Science.gov (United States)

    2013-09-01

    28 4.1.3 Fort Bliss , TX .......................................................................................29 4.1.4 Marine Corps Air Ground...Norfolk; Shawn Bogdan, Matt Siler and Kyle Hess at Naval War College, Newport; Marisela Leyva at Fort Bliss , TX; Clovis Vaughn and Andrew Burton at...team at Heschong Mahone Group (now part of TRC Companies): Lisa Heschong, Abhijeet Pande, Mudit Agarwal and Tim Perry for their immense contribution

  3. Daylight Redirecting Window Film

    Science.gov (United States)

    2013-12-01

    Fort Bliss , TX; Clovis Vaughn and Andrew Burton at 29 Palms, CA; Doug Taber at Naval Post Graduate School (NPS), Monterey; and Mitch Hailey at Naval...Agarwal and Tim Perry for their immense contribution to this project. Finally, throughout the project, the guidance and counseling of Vern Novstrup at...and control) VA Norfolk Z-133 1 1 1 6 72 48 120 CA 29 Palms 1416 5 7 14 13 108 31 62 RI Newport Hewitt Hall 2 5 9 19 88 24 40 TX Fort Bliss

  4. Color tuning in alert macaque V1 assessed with fMRI and single-unit recording shows a bias toward daylight colors.

    Science.gov (United States)

    Lafer-Sousa, Rosa; Liu, Yang O; Lafer-Sousa, Luis; Wiest, Michael C; Conway, Bevil R

    2012-05-01

    Colors defined by the two intermediate directions in color space, "orange-cyan" and "lime-magenta," elicit the same spatiotemporal average response from the two cardinal chromatic channels in the lateral geniculate nucleus (LGN). While we found LGN functional magnetic resonance imaging (fMRI) responses to these pairs of colors were statistically indistinguishable, primary visual cortex (V1) fMRI responses were stronger to orange-cyan. Moreover, linear combinations of single-cell responses to cone-isolating stimuli of V1 cone-opponent cells also yielded stronger predicted responses to orange-cyan over lime-magenta, suggesting these neurons underlie the fMRI result. These observations are consistent with the hypothesis that V1 recombines LGN signals into "higher-order" mechanisms tuned to noncardinal color directions. In light of work showing that natural images and daylight samples are biased toward orange-cyan, our findings further suggest that V1 is adapted to daylight. V1, especially double-opponent cells, may function to extract spatial information from color boundaries correlated with scene-structure cues, such as shadows lit by ambient blue sky juxtaposed with surfaces reflecting sunshine. © 2012 Optical Society of America

  5. One-pot solvothermal synthesis of highly efficient, daylight active and recyclable Ag/AgBr coupled photocatalysts with synergistic dual photoexcitation

    International Nuclear Information System (INIS)

    Zhang, Caihong; Ai, Lunhong; Li, Lili; Jiang, Jing

    2014-01-01

    Highlights: • Ag/AgBr photocatalysts were controllably synthesized by solvothermal process. • Ag/AgBr composites showed excellent daylight driven photocatalytic activity. • The remarkable activity is attributed to the synergistic dual photoexcitation. -- Abstract: Efficient light harvesting has been considered to be critical for manipulating the photocatalytic behavior of photocatalysts, because it directly determines the generation of reactive redox charge carriers involved in photoreaction process. In this study, we present a successful example on efficient conversion of solar energy by Ag/AgBr coupled photocatalysts that hold unique synergistic dual photoexcitation. A series of Ag/AgBr coupled photocatalysts were controllably synthesized by an easily manipulated mild solvothermal process. The physicochemical properties of the as-prepared Ag/AgBr coupled photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS) and UV–vis diffuse reflectance spectroscopy (DRS). The results showed the solvothermal reaction time played key role for control of crystalline structure, morphology, composition, and visible light absorption ability of the resulting photocatalysts. The as-prepared Ag/AgBr coupled photocatalysts exhibited remarkable photocatalytic performance and good reusability for decomposing organic dyes in aqueous solution under the irradiation of commercial 20 W cool daylight fluorescent lamp, owing to the synergistic dual photoexcitation cooperating between plasmonic Ag nanoparticles and narrow-band-gap AgBr

  6. Quantifying the radiant exposure and effective dose in patients treated for actinic keratoses with topical photodynamic therapy using daylight and LED white light

    Science.gov (United States)

    Manley, M.; Collins, P.; Gray, L.; O'Gorman, S.; McCavana, J.

    2018-02-01

    Daylight photodynamic therapy (dl-PDT) is as effective as conventional PDT (c-PDT) for treating actinic keratoses but has the advantage of reducing patient discomfort significantly. Topical dl-PDT and white light-PDT (wl-PDT) differ from c-PDT by way of light sources and methodology. We measured the variables associated with light dose delivery to skin surface and influence of geometry using a radiometer, a spectral radiometer and an illuminance meter. The associated errors of the measurement methods were assessed. The spectral and spatial distribution of the radiant energy from the LED white light source was evaluated in order to define the maximum treatment area, setup and treatment protocol for wl-PDT. We compared the data with two red LED light sources we use for c-PDT. The calculated effective light dose is the product of the normalised absorption spectrum of the photosensitizer, protoporphyrin IX (PpIX), the irradiance spectrum and the treatment time. The effective light dose from daylight ranged from 3  ±  0.4 to 44  ±  6 J cm-2due to varying weather conditions. The effective light dose for wl-PDT was reproducible for treatments but it varied across the treatment area between 4  ±  0.1 J cm-2 at the edge and 9  ±  0.1 J cm-2 centrally. The effective light dose for the red waveband (615-645 nm) was 0.42  ±  0.05 J cm-2 on a clear day, 0.05  ±  0.01 J cm-2 on an overcast day and 0.9  ±  0.01 J cm-2 using the white light. This compares with 0.95  ±  0.01 and 0.84  ±  0.01 J cm-2 for c-PDT devices. Estimated errors associated with indirect determination of daylight effective light dose were very significant, particularly for effective light doses less than 5 J cm-2 (up to 83% for irradiance calculations). The primary source of error is in establishment of the relationship between irradiance or illuminance and effective dose. Use of the O’Mahoney model is recommended using a

  7. Use of a Novel Rover-mounted Fluorescence Imager and Fluorescent Probes to Detect Biological Material in the Atacama Desert in Daylight

    Science.gov (United States)

    Weinstein, S.; Pane, D.; Warren-Rhodes, K.; Cockell, C.; Ernst, L. A.; Minkley, E.; Fisher, G.; Emani, S.; Wettergreen, D. S.; Wagner, M.

    2005-01-01

    We have developed an imaging system, the Fluorescence Imager (FI), for detecting fluorescence signals from sparse microorganisms and biofilms during autonomous rover exploration. The fluorescence signals arise both from naturally occurring chromophores, such as chlorophyll of cyanobacteria and lichens, and from fluorescent probes applied to soil and rocks. Daylight imaging has been accomplished by a novel use of a high-powered flashlamp synchronized to a CCD camera. The fluorescent probes are cell permanent stains that have extremely low intrinsic fluorescence (quantum yields less than 0.01) and a large fluorescence enhancement (quantum yields greater than 0.4) when bound to the target. Each probe specifically targets either carbohydrates, proteins, nucleic acids or membrane lipids, the four classes of macromolecules found in terrestrial life. The intent of the probes is to interrogate the environment for surface and endolithic life forms.

  8. The daylight alternative for energy conservation saving in lighting systems; La luz natural alternativa para el ahorro de energia en sistemas de iluminacion

    Energy Technology Data Exchange (ETDEWEB)

    Escutia Perez, A.; Cruz Mendez, E. P. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Mexico D. F. (Mexico); Buitron Sanchez, H. [Programa de Ahorro de Energia del Sector Electrico, Mexico D. F. (Mexico)

    1995-12-31

    The technological advances generate far reaching changes in all types of installation. The new spaces and the existing ones justify the introduction of new technologies taking into account important economic considerations, mostly when the advantage of daylight is taken into consideration in industrial and commercial lighting. In the daylight design it is necessary to know the solar transit, the atmospheric conditions, the architectural design of the building, the materials and the control elements, etc. to apply with precision the calculation method. The fundamental lighting technic have varied little. In the greatest part of commerces and industries the general lighting is used, that produces an illumination more or less uniform on the working areas, which guarantees a total freedom for the placement of machinery, working benches, racks, exhibitors, clothes racks, etc.. This type of lighting is obtained by means of the use of a more or less regular series of skylights. The adequate localized lighting is used in those zones where because of the presence of obstructions or unfavorable slant of the working plan are not sufficiently well lighted by the general lighting system. The daylight use in accordance with the every moment availability will permit in many working centers a sensible diminution of the artificial lighting time, provided that the characteristics of the control operation of the installation permit it, along with modern controlling devices and the great variety of efficient saving lamps. [Espanol] Los avances tecnologicos generan cambios trascendentes en todo tipo de instalacion. Los nuevos espacios y los ya existentes justifican la introduccion de nuevas tecnologias teniendo consideraciones economicas importantes, sobre todo cuando se aprovecha la luz natural en sistemas de alumbrado industrial y comercial. En el diseno de iluminacion natural, es necesario tener el conocimiento del transito solar, las condiciones atmosfericas, el diseno

  9. The daylight alternative for energy conservation saving in lighting systems; La luz natural alternativa para el ahorro de energia en sistemas de iluminacion

    Energy Technology Data Exchange (ETDEWEB)

    Escutia Perez, A; Cruz Mendez, E P [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Mexico D. F. (Mexico); Buitron Sanchez, H [Programa de Ahorro de Energia del Sector Electrico, Mexico D. F. (Mexico)

    1996-12-31

    The technological advances generate far reaching changes in all types of installation. The new spaces and the existing ones justify the introduction of new technologies taking into account important economic considerations, mostly when the advantage of daylight is taken into consideration in industrial and commercial lighting. In the daylight design it is necessary to know the solar transit, the atmospheric conditions, the architectural design of the building, the materials and the control elements, etc. to apply with precision the calculation method. The fundamental lighting technic have varied little. In the greatest part of commerces and industries the general lighting is used, that produces an illumination more or less uniform on the working areas, which guarantees a total freedom for the placement of machinery, working benches, racks, exhibitors, clothes racks, etc.. This type of lighting is obtained by means of the use of a more or less regular series of skylights. The adequate localized lighting is used in those zones where because of the presence of obstructions or unfavorable slant of the working plan are not sufficiently well lighted by the general lighting system. The daylight use in accordance with the every moment availability will permit in many working centers a sensible diminution of the artificial lighting time, provided that the characteristics of the control operation of the installation permit it, along with modern controlling devices and the great variety of efficient saving lamps. [Espanol] Los avances tecnologicos generan cambios trascendentes en todo tipo de instalacion. Los nuevos espacios y los ya existentes justifican la introduccion de nuevas tecnologias teniendo consideraciones economicas importantes, sobre todo cuando se aprovecha la luz natural en sistemas de alumbrado industrial y comercial. En el diseno de iluminacion natural, es necesario tener el conocimiento del transito solar, las condiciones atmosfericas, el diseno

  10. The methodology for the evaluation of the energy saving by the daylight saving time in Mexico; Metodologia para la evaluacion del ahorro de energia debido al cambio de horario durante la epoca del verano

    Energy Technology Data Exchange (ETDEWEB)

    Ramos Niembro, Gaudencio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    A description is made of the methodology for the evaluation of energy saving by the daylight saving time in Mexico. A mathematical model was developed that would allow the quantitative evaluation of the energy saving by the daylight saving time, through measurements of the consumption of different users from the domestic commercial and industrial sector, considering the various variables that impact the consumption [Espanol] Se describe la metodologia para la evalucion del ahorro de energia por el cambio de horario de verano en Mexico. Se desarrollo un modelo matematico que permitiera evaluar cuantitativamente el ahorro de energia debido al cambio de horario durante la epoca de verano, atraves de mediciones de consumos de los diferentes usuarios de los sectores domestico, comercial e industrial, considerando las diversas variables que impactan en el consumo

  11. The methodology for the evaluation of the energy saving by the daylight saving time in Mexico; Metodologia para la evaluacion del ahorro de energia debido al cambio de horario durante la epoca del verano

    Energy Technology Data Exchange (ETDEWEB)

    Ramos Niembro, Gaudencio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    A description is made of the methodology for the evaluation of energy saving by the daylight saving time in Mexico. A mathematical model was developed that would allow the quantitative evaluation of the energy saving by the daylight saving time, through measurements of the consumption of different users from the domestic commercial and industrial sector, considering the various variables that impact the consumption [Espanol] Se describe la metodologia para la evalucion del ahorro de energia por el cambio de horario de verano en Mexico. Se desarrollo un modelo matematico que permitiera evaluar cuantitativamente el ahorro de energia debido al cambio de horario durante la epoca de verano, atraves de mediciones de consumos de los diferentes usuarios de los sectores domestico, comercial e industrial, considerando las diversas variables que impactan en el consumo

  12. Experimental analysis on a 1:2 scale model of the double light pipe, an innovative technological device for daylight transmission

    Energy Technology Data Exchange (ETDEWEB)

    Baroncini, C.; Boccia, O.; Chella, F.; Zazzini, P. [D.S.S.A.R.R. Faculty of Architecture, University ' ' G. D' Annunzio' ' Viale Pindaro 42, 65127 Pescara (Italy)

    2010-02-15

    In this paper the authors present the double light pipe, an innovative technological device, designed as an evolution of a traditional light pipe, which distributes daylight to underground areas of a building, illuminating, at the same time, the passage areas thanks to a larger collector and a second transparent pipe attached to the first one. Unlike the traditional light pipe, thanks to this double illuminating function it can be located in the middle of a room, despite its encumbrance. In this paper the technological design of the double light pipe is presented and the results of an experimental analysis on a reduced scale (1:2) model are shown. Internal illuminance data over horizontal and vertical work-planes were measured in various sky conditions with or without direct solar radiation. Being this innovative device obtained by a light pipe integrated with a second pipe, it performs like a traditional light pipe for the final room and, at the same time, illuminates the intermediate room giving it uniform and high quality light, particularly indicated for wide plant areas, such as show-rooms or museums. (author)

  13. Relative roles of emissions and meteorology in the diurnal pattern of urban PM10: analysis of the daylight saving time effect.

    Science.gov (United States)

    Muñoz, Ricardo C

    2012-06-01

    Daylight saving time (DST) is a common practice in many countries, in which Official Time (OT) is abruptly shifted 1 hour with respect to solar time on two occasions every year (in fall and spring). All anthropogenic emitting processes tied to OT like job and school commuting traffic, abruptly change in this moment their timing with respect to solar time, inducing a sudden shift between emissions and the meteorological factors that control the dispersion and transport of air pollutants. Analyzing 13 years of hourly particulate matter (PM10) concentrations measured in Santiago, Chile, we demonstrate that the DST practice has observable non-trivial effects in the PM10 diurnal cycle. The clearest impact is in the morning peak of PM10 during the fall DST change, which occurs later and has on average a significant smaller magnitude in the days after the DST change as compared to the days before it. This decrease in magnitude is most remarkable because it occurs in a period of the year when overall PM10 concentrations increase due to generally worsening of the dispersion conditions. Results are shown for seven monitoring stations around the city, and for the fall and spring DST changes. They show clearly the interplay of emissions and meteorology in conditioning urban air pollution problems, highlighting the role of the morning and evening transitions of the atmospheric boundary layer in shaping the diurnal pattern of urban air pollutant concentrations.

  14. Energy optimised lighting in buildings with simultaneous improvement of quality of life by daylight utilisation and innovative lamps and ballast techniques; Energieoptimierte Beleuchtung bei gleichzeitiger Verbesserung der Lebensqualitaet durch Nutzung von Tageslicht und neuer Lampen- und Vorschalttechnik

    Energy Technology Data Exchange (ETDEWEB)

    Kaase, Heinrich; Aydinli, Sirri; Gramm, Stefan; Thiel, Stefan [Technische Universitaet Berlin, Fakultaet IV Elektrotechnik und Informatik, FG Lichttechnik, Berlin (Germany); De Boer, Jan; Erhorn, Hans [Fraunhofer-Institut fuer Bauphysik, Stuttgart (Germany); Kuhn, Tilman; Wienold, Jan [Fraunhofer-Institut fuer Solare Energiesysteme, Freiburg (Germany); Hillmann, Gustav; Korolkow, Margarethe [IBUS GmbH, Berlin (Germany); Piazena, Helmut [Universitaetsklinikum Charite, Berlin (Germany)

    2012-06-15

    The scientific and technical goals of this project were developed in five parts. The individual topics arising from current issues, they still have a generally applicable nature. The consortium has worked on the following subprojects: (1) Development of a measurement technique to determine energy and photometric key figures of daylight components with a round robin test with three institutes. (2) Implementation of a detailed evaluation and documentation process for daylighting of interior spaces in different climate zones. (3) For lighting control in private living areas a ''Power Line Carrier Communication'' system has been evaluated and the advantages of a wireless transmission system were identified. (4) In a home for elderly quantitative studies on the well-being, for the fulfillment of visual tasks and the capability of melatonin suppression at different scenarios of general lighting with two different color temperatures of lamps (''warm white'' with TCP = 3000 K and ''cold white daylight'' with TCP = 6500 K) and vertical illuminance at the eyes of the subjects between 100 lx and 700 lx were performed. (5) For two school buildings in Berlin, the final energy consumption of the existing lighting system, the reference building and a re-planning were determined. It became clear in both examples that the existing lighting system exceeds the permitted value (EnEV 2009) by far. A good redesign, however, can be significantly less than the maximum allowed value. These studies were accompanied by a one-year monitoring of energy consumption. A cross-sectional analysis of 48 schools with a total of 86 buildings shows a substantial need for renovation of school buildings that were built before 1990.

  15. Placing rooms in the right light. Targeted daylight and optimised artificial lighting help to improve comfort; Raeume ins richtige Licht ruecken. Gezielt eingesetztes Tageslicht und optimierte kuenstliche Beleuchtung helfen, das Wohlbefinden zu verbessern

    Energy Technology Data Exchange (ETDEWEB)

    Durst, Anna

    2012-11-01

    Regardless whether in the office, at home or in school, too little daylight or unfavourable lighting impair visibility in rooms and strain the eyes. Based on the example of schools and homes for the elderly, it was investigated how new lighting concepts and new lamp, luminaire and ballast technology can help to improve the situation. A measurement system was used to monitor the lighting and energy properties. The new lighting systems and optimised technology enabled the electrical energy requirements in a school to be reduced by around two thirds. (orig.)

  16. Tips for daylighting with windows

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Alastair [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Selkowitz, Stephen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-10-01

    These guidelines provide an integrated approach to the cost-effective design of perimeter zones in new commercial buildings and existing building retrofits. They function as a quick reference for building designers, through a set of easy steps and rules-of-thumb, emphasizing “how-to” practical details. References are given to more detailed sources of information, should the reader wish to go further. The design method used in this document emphasizes that building decisions should be made within the context of the whole building as a single functioning system rather than as an assembly of distinct parts. This integrated design approach looks at the ramifications of each individual system decision on the whole building. For example, the decision on glazing selection will have an effect on lighting, mechanical systems, and interior design. Therefore, the entire design team should participate and influence this glazing decision—which typically rests with the architect alone. The benefit of an integrated design approach is a greater chance of success towards long-term comfort and sustained energy savings in the building.

  17. Daylight-driven photocatalytic degradation of ionic dyes with negatively surface-charged In{sub 2}S{sub 3} nanoflowers: dye charge-dependent roles of reactive species

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Suxiang [Xuchang University, Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, and School of Chemistry and Chemical Engineering (China); Cai, Lejuan, E-mail: 494169965@qq.com [Central China Normal University, Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry (China); Li, Dapeng, E-mail: lidapengabc@126.com; Fa, Wenjun; Zhang, Yange; Zheng, Zhi [Xuchang University, Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, and School of Chemistry and Chemical Engineering (China)

    2015-12-15

    Even though dye degradation is a successful application of semiconductor photocatalysis, the roles of reactive species in dye degradation have not received adequate attention. In this study, we systematically investigated the degradation of two cationic dyes (rhodamine B and methylene blue) and two anionic dyes (methyl orange and orange G) over negatively surface-charged In{sub 2}S{sub 3} nanoflowers synthesized at 80 °C under indoor daylight lamp irradiation. It is notable to find In{sub 2}S{sub 3} nanoflowers were more stable in anionic dyes degradation compared to that in cationic dyes removal. The active species trapping experiments indicated photogenerated electrons were mainly responsible for cationic dyes degradation, but holes were more important in anionic dyes degradation. A surface-charge-dependent role of reactive species in ionic dye degradation was proposed for revealing such interesting phenomenon. This study would provide a new insight for preparing highly efficient daylight-driven photocatalyst for ionic dyes degradation.

  18. The supermarket of the future saves energy. Shop links food refrigeration to room temperature control, and supplements artificial lighting with daylight; Supermarkt der Zukunft spart Energie. Laden koppelt Lebensmittelkuehlung mit Raumtemperierung und ergaenzt die Beleuchtung durch Tageslicht

    Energy Technology Data Exchange (ETDEWEB)

    Gintars, Dorothee

    2013-07-01

    The energy savings division at the discount store Aldi Sued in Rastatt should in the future only need two-thirds of the primary energy usually required for refrigeration, heating, ventilation, air conditioning and lighting. A compressor pack with carbon dioxide as a coolant which has been developed in-house, and which is coupled to borehole heat exchangers, not only cools food, but also provides temperature control for indoor areas. The energy concept, which has been developed at the ISE Fraunhofer Institute for Solar Energy Systems, is rounded off by a well insulated building envelope, the use of daylight and efficient ventilation. In the third year of operation, the amount of energy consumed is coming close to the ambitious target levels. (orig.)

  19. Effects of sunshades and daylighting systems on room climate in the new building of the Baden-Wuerttemberg office for listed buildings in Esslingen; Auswirkungen von Sonnenschutz/Tageslichtsystemen auf das Raumklima beim Neubau Landesdenkmalamt Esslingen

    Energy Technology Data Exchange (ETDEWEB)

    Buehler, H.J. [GN Bauphysik, Ingenieurgesellschaft mbH, Stuttgart (Germany)

    2003-07-01

    Visual and thermal comfort have a crucial influence on the well-being of the users. With conventional sun protective systems the simultaneous implementation of both requirements is hardly to be carried out. By means of retroflecting sun protective systems type RETROLux Therm can be achieved an optimal daylight illuminating and at the same time a minimization of the summer energy entry. There is for the angles of incidence conditions in the summer months total energy transmission factors (g-value) of 0.10 to expect with simultaneous visual communication with the environment. The sun protective effect is therefore comparable with a conventional external blind system, which exhibits however a substantially limited external outlook. Newest test certificates of the RetroLux Therm lamellas show that in connection with highly reflecting lamella surfaces total energy transmission factors under g=0.10 can be achieved. By thermal simulation calculations it could be proved that with the planned facade conception on basis of the retroreflection no disadvantages are to be expected regarding room climate and operating cost in relation to a conventional facade system with external blinds. The planned facade conception forms thereby together with the building-technical conception of the construction unit activation and the multi-functionally used edge strip a conclusive primary energetically favorable energy concept. (orig.)

  20. A cyclic nucleotide-gated channel mutation associated with canine daylight blindness provides insight into a role for the S2 segment tri-Asp motif in channel biogenesis.

    Directory of Open Access Journals (Sweden)

    Naoto Tanaka

    Full Text Available Cone cyclic nucleotide-gated channels are tetramers formed by CNGA3 and CNGB3 subunits; CNGA3 subunits function as homotetrameric channels but CNGB3 exhibits channel function only when co-expressed with CNGA3. An aspartatic acid (Asp to asparagine (Asn missense mutation at position 262 in the canine CNGB3 (D262N subunit results in loss of cone function (daylight blindness, suggesting an important role for this aspartic acid residue in channel biogenesis and/or function. Asp 262 is located in a conserved region of the second transmembrane segment containing three Asp residues designated the Tri-Asp motif. This motif is conserved in all CNG channels. Here we examine mutations in canine CNGA3 homomeric channels using a combination of experimental and computational approaches. Mutations of these conserved Asp residues result in the absence of nucleotide-activated currents in heterologous expression. A fluorescent tag on CNGA3 shows mislocalization of mutant channels. Co-expressing CNGB3 Tri-Asp mutants with wild type CNGA3 results in some functional channels, however, their electrophysiological characterization matches the properties of homomeric CNGA3 channels. This failure to record heteromeric currents suggests that Asp/Asn mutations affect heteromeric subunit assembly. A homology model of S1-S6 of the CNGA3 channel was generated and relaxed in a membrane using molecular dynamics simulations. The model predicts that the Tri-Asp motif is involved in non-specific salt bridge pairings with positive residues of S3/S4. We propose that the D262N mutation in dogs with CNGB3-day blindness results in the loss of these inter-helical interactions altering the electrostatic equilibrium within in the S1-S4 bundle. Because residues analogous to Tri-Asp in the voltage-gated Shaker potassium channel family were implicated in monomer folding, we hypothesize that destabilizing these electrostatic interactions impairs the monomer folding state in D262N mutant CNG

  1. Daylight case study building. A working document of Task 21. Daylight in buildings

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, P E

    1997-05-01

    This report describes 16 buildings, that have been selected as Task 21 case studies. Totally 15 buildings will be monitored and described according to the procedures developed in Task 21. One case study building is in design stage, the new ISE Headquarters in Freiburg, and this project has been selected as a case study on building design. The monitoring programme for the buildings runs through 1997 until mid 1998. The present document serves as a basic document describing the case studies, until the projects will be described in more detail, including monitoring results, towards the end of the Task. (au)

  2. EFICIENCIA ENERGÉTICA POR LA UTILIZACIÓN DE COMPONENTES DE CONDUCCIÓN DE LUZ NATURAL EN CLIMA CÁLIDO-HÚMEDO | ENERGETIC EFFICIENCY DERIVED FROM THE USE OF CONDUCTION COMPONENTS OF DAYLIGHT IN WARM-HUMID CLIMATE

    Directory of Open Access Journals (Sweden)

    Rosalinda González Gómez

    2015-11-01

    Full Text Available The electric energy saving was estimated by the utilization of Conduction Components of Daylight (CCD in warm-humid climate. For this, the luminic performance of the component was determined, considering values of horizontal exterior lighting and interior lighting obtained by monitoring under real sky conditions in scale models, and the comparison with incandescent bulbs and Compact Fluorescent Lamps (CFL. The utilization of the natural light through CCLN allows to obtain a saving in the expense for energy, with respect to the use of Incandescent Bulb and/or Compact Fluorescent Lamp (artificial lighting. In this sense, their use would correspond to 219 KWh and to 54.75 KWh, respectively, if they are used for an average of 10 daily hours, during a period of one year. It was estimated that a possible reduction could be achieved in the electricity consumption, maintaining the comfort and quality of life of the users in buildings (high luminic performance without use of energy from commercial supplier, contributing this way to the "energy efficiency" in them.

  3. Dynamic Lighting Concept in Danish Office Environment with Daylight Contribution

    DEFF Research Database (Denmark)

    Logadóttir, Ásta; Christoffersen, Jens

    positioned ~2 respectively ~4 meters from the window. Both the general lighting and desk lamp could be adjusted in correlated colour temperature (CCT) while the general lighting could also be adjusted in intensity. The study was an extension of previous studies conducted without a desk lamp and with subjects...

  4. Modeling illumination performance of plastic optical fiber passive daylighting system

    Energy Technology Data Exchange (ETDEWEB)

    Sulaiman, F; Ahmad, A [Universiti Teknologi MARA, Shah Alam (Malaysia). Faculty of Electrical Engineering; Ahmed, A Z [Universiti Teknologi MARA, Shah Alam (Malaysia). Bureau of Reseaarch and Consultancy

    2006-12-15

    of the most direct methods of utilizing solar energy for energy conservation is to bring natural light indoors to light up an area. This paper reports on the investigation of the feasibility to utilize large core optical fibers to convey and distribute solar light passively throughout residential or commercial structures. The focus of this study is on the mathematical modeling of the illumination performance and the light transmission efficiency of solid core end light fiber for optical day lighting systems. The Meatball simulations features the optical fiber transmittance for glass and plastic fibers, illumination performance over lengths of plastic end-lit fiber, spectral transmission, light intensity loss through the large diameter solid core optical fibers as well as the transmission efficiency of the optical fiber itself. It was found that plastic optical fiber has less transmission loss over the distance of the fiber run which clearly shows that the Plastic Optical Fiber should be optimized for emitting visible light. The findings from the analysis on the performance of large diameter optical fibers for day lighting systems seems feasible for energy efficient lighting system in commercial or residential buildings.

  5. Modeling illumination performance of plastic optical fiber passive daylighting system

    International Nuclear Information System (INIS)

    Sulaiman, F.; Ahmad, A.; Ahmed, A.Z.

    2006-01-01

    One of the most direct methods of utilizing solar energy for energy conservation is to bring natural light indoors to light up an area. This paper reports on the investigation of the feasibility to utilize large core optical fibers to convey and distribute solar light passively throughout residential or commercial structures. The focus of this study is on the mathematical modeling of the illumination performance and the light transmission efficiency of solid core end light fiber for optical day lighting systems. The Meatball simulations features the optical fiber transmittance for glass and plastic fibers, illumination performance over lengths of plastic end-lit fiber, spectral transmission, light intensity loss through the large diameter solid core optical fibers as well as the transmission efficiency of the optical fiber itself. It was found that plastic optical fiber has less transmission loss over the distance of the fiber run which clearly shows that the Plastic Optical Fiber should be optimized for emitting visible light. The findings from the analysis on the performance of large diameter optical fibers for day lighting systems seems feasible for energy efficient lighting system in commercial or residential buildings

  6. Daylighting Digital Dimmer SBIR Phase 2 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Morgan [MoJo Labs Inc., Longmont, CO (United States)

    2018-01-17

    The primary focus of the Phase II Development is the implementation of two key technologies, Task To Wall (TTW) Control, and Wand Gesture light dimming control into an easy to use remote for SSL light control, the MoJo Remote. The MoJo Remote product family includes a battery powered wireless remote, a WiFi gateway as well as Mobile Applications for iOS and Android. Specific accomplishments during the second reporting period include: 1. Finalization and implementation of MoJo Remote Accelerometer and capacitive-touch based UI/UX, referred to as the Wand Gesture UI. 2. Issuance of Patent for Wand Gesture UI. 3. Industrial and Mechanical Design for MoJo Remote and MoJo Gateway. 4. Task To Wall implementation and testing in MoJo Remote. 5. Zooming User Interface (ZUI) for the Mobile App implemented on both iOS and Andriod. 6. iOS Mobile app developed to beta level functionality. 7. Initial Development of the Android Mobile Application. 8. Closed loop color control at task (demonstrated at 2016 SSL R&D Workshop). 9. Task To Wall extended to Color Control, working in simulation. 10. Beta testing begun in Late 2017/Early 2018. The MoJo Remote integrates the Patented TTW Control and the Wand Gesture innovative User Interface, and is currently in Beta testing and on the path to commercialization.

  7. Infrared Methods for Daylight Acquisition of LEO Satellites

    National Research Council Canada - National Science Library

    Nelson, Joel

    2004-01-01

    ..., and very capable space surveillance systems. The first product of the Raven program was a family of telescopes capable of generating world-class optical observation data of deep-space satellites...

  8. Burning daylight: balancing vitamin D requirements with sensible sun exposure.

    Science.gov (United States)

    Stalgis-Bilinski, Kellie L; Boyages, John; Salisbury, Elizabeth L; Dunstan, Colin R; Henderson, Stuart I; Talbot, Peter L

    2011-04-04

    To examine the feasibility of balancing sunlight exposure to meet vitamin D requirements with sun protection guidelines. We used standard erythemal dose and Ultraviolet Index (UVI) data for 1 June 1996 to 30 December 2005 for seven Australian cities to estimate duration of sun exposure required for fair-skinned individuals to synthesise 1000 IU (25 µg) of vitamin D, with 11% and 17% body exposure, for each season and hour of the day. Periods were classified according to whether the UVI was 60 min. Duration of sunlight exposure required to achieve 1000 IU of vitamin D synthesis. Duration of sunlight exposure required to synthesise 1000 IU of vitamin D varied by time of day, season and city. Although peak UVI periods are typically promoted as between 10 am and 3 pm, UVI was often ≥ 3 before 10 am or after 3 pm. When the UVI was sunlight exposure while avoiding its damaging effects. Physiological and geographical factors may reduce vitamin D synthesis, and supplementation may be necessary to achieve adequate vitamin D status for individuals at risk of deficiency. ©The Medical Journal of Australia 2011

  9. DAYLIGHTING AND ENERGY PERFORMANCE OF POST MILLENIUM CONDOMINIUMS IN SINGAPORE

    Directory of Open Access Journals (Sweden)

    Uma Maheswaran

    2007-03-01

    habitable spaces in their residence. This paper is an attempt to discuss a few examples of condominiums around the western part of Singapore as a means of discussing the emerging design trends as well as to discuss the performance aspects of the design solutions in terms of day lighting and energy consumption.

  10. The dioxins in broad daylight; Les dioxines au grand jour

    Energy Technology Data Exchange (ETDEWEB)

    Claveri, B.; Mersch, J. [BioMonitor, 57 - Florange (France)

    2001-07-01

    In the framework of the Eco-Industries 2000 meeting, the ATEE organized a colloquium on the dioxins in the environment. This book presents the seven papers proposed at this colloquium bringing information on the dioxins and the furans molecular structure, their biological impacts on the environment, the monitoring and regulations in the domain and some example of remedial actions in the metal and wood industry. (A.L.B.)

  11. Entanglement-based Free Space Quantum Cryptography in Daylight

    Science.gov (United States)

    Gerhardt, Ilja; Peloso, Matthew P.; Ho, Caleb; Lamas-Linares, Antia; Kurtsiefer, Christian

    2009-05-01

    In quantum key distribution (QKD) two families of protocols are established: One, based on preparing and sending approximations of single photons, the other based on measurements on entangled photon pairs, which allow to establish a secret key using less assumptions on the size of a Hilbert space. The larger optical bandwidth of photon pairs in comparison with light used for the first family makes establishing a free space link challenging. We present a complete entanglement based QKD system following the BBM92 protocol, which generates a secure key continuously 24 hours a day between distant parties. Spectral, spatial and temporal filtering schemes were introduced to a previous setup, suppressing more than 30,B of background. We are able to establish the link during daytime, and have developed an algorithm to start and maintain time synchronization with simple crystal oscillators.

  12. Intelligent building envelopes. Architectural concept and applications for daylighting quality

    Energy Technology Data Exchange (ETDEWEB)

    Wyckmans, Annemie

    2005-11-15

    How does an intelligent building envelope manage the variable and sometimes conflictive occupant requirements that arise in a day lit indoor environment. This is the research question that provides the basis for this Ph.D. work. As it touches upon several fields of application, the research question is untangled into four steps, each of which corresponds to a chapter of the thesis. 1) What characterises intelligent behaviour for a building envelope. 2) What characterises indoor day lighting quality. 3) Which functions can an intelligent building envelope be expected to perform in the context of day lighting quality. 4) How are the materials, components and composition of an intelligent building envelope designed to influence this performance. The emphasis is on design, environmental aspects, energy conservation, functional analysis and physical applications.

  13. Results of the study on the impact of the daylight saving time in Mexico that was coordinated by the Universidad Nacional Autonoma de Mexico; Resultados del estudio sobre el impacto del horario de verano en Mexico que fue coordinado por la Universidad Nacional Autonoma de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Velez Ocon, Carlos [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2001-07-01

    Due to the multiple discussions that were raised in ample sectors of the society on the occasion of the implantation of the daylight saving last year, the Federal Government offered to make an integral study of the impact that causes this measure in the Mexican society. Later, the Secretariat of Energy asked for this study to Universidad Nacional Autonoma de Mexico (UNAM). In talks with the representatives of that Secretariat, it was determined that the study had to cover the largest number of sectors and activities of the society in which it could exist a suspicion of impact by this change, and which in addition had an important relevance in the life of the society. These areas were eighteen, that are listed in alphabetical as follows: agriculture, commerce, education, energy, family, finances, cattle raising, individual, industry, environment, mass media, health, public security, telecommunications, free time, transport, tourism, border zones. Altogether 70 institutions, 121 professors and investigators participated, 36 of which pertain to 15 dependencies of the UNAM; 46% belong to institutions in the Federal District and 54% to private institutions. It is worth to clarify that the time that was granted to make the study was of three months as of 1 May, which gave little margin to make specific studies with the purpose of successfully obtaining new information. Most of the analysis was made with already existing information in the corresponding sectors. [Spanish] Debido a las multiples discusiones que se suscitaron en amplios sectores de la sociedad con motivo de la implantacion del horario de verano el ultimo anos, el Gobierno Federal ofrecio realizar un estudio integral del impacto que causa esta medida en la sociedad mexicana. Posteriormente, la Secretaria de Energia le solicito este estudio a la Universidad Nacional Autonoma de Mexico (UNAM). En platicas con los representantes de esa Secretaria, se determino que el estudio debia cubrir el mayor numero de

  14. Simplified Daylight Spectrum Approximation by Blending Two Light Emitting Diode Sources

    Science.gov (United States)

    2012-03-01

    Iota Epsilon (SIE). Michael E. Miller, PhD is an Assistant Professor of Human Systems Integration at the Air Force Institute of Technology. His...USA. Dr Grimaila’s research interests include mission assurance, network management 49 and security , quantum information warfare, and systems...Engineers (SAME) and Sigma Iota Epsilon (SIE). John Colombi, Ph.D. is an Assistant Professor of Systems Engineering at the Air Force Institute of

  15. Life cycle cost optimization of buildings with regard to energy use, thermal indoor environment and daylight

    DEFF Research Database (Denmark)

    Nielsen, Toke Rammer; Svendsen, Svend

    2002-01-01

    by the life cycle cost taking all expenses in the buildings service life into consideration. Also the performance of buildings is important as the performance influences the comfort of the occupants, heating demand etc. Different performance requirements are stated in building codes, standards......Buildings represent a large economical investment and have long service lives through which expenses for heating, cooling, maintenance and replacement depends on the chosen building design. Therefore, the building cost should not only be evaluated by the initial investment cost but rather...... and by the customer. The influence of different design variables on life cycle cost and building performance is very complicated and the design variables can be combined in an almost unlimited number of ways. Optimization can be applied to achieve a building design with low life cycle cost and good performance...

  16. The urban canyon and building energy use: Urban density versus daylight and passive solar gains

    DEFF Research Database (Denmark)

    Strømann-Andersen, Jakob Bjørn; Sattrup, Peter Andreas

    2011-01-01

    .It was found that the geometry of urban canyons has an impact on total energy consumption in the range of up to +30% for offices and +19% for housing, which shows that the geometry of urban canyons is a key factor in energy use in buildings. It was demonstrated how the reflectivity of urban canyons plays...

  17. Daylight integrated illumination control of LED systems based on enhanced presence sensing

    NARCIS (Netherlands)

    Pandharipande, A.; Caicedo Fernandez, D.R.

    2011-01-01

    Light emitting diodes (LEDs) are considered to become the dominant source of illumination in the future, offering long life times, energy efficiency and flexible tunability. The flexibility of adapting LED parameters offers multiple degrees of freedom in designing LED based lighting systems. In this

  18. ONCE AGAIN ABOUT GHOSTS: IN DREAMS, IN THE DAYLIGHT, IN THE ETYMOLOGY

    OpenAIRE

    A. Loma

    2015-01-01

    The paper aims to reconsider the etymology  of South-Slavic folklore term neveda  ‘maleficent supernatural being, misfortune’, hitherto interpreted as *ne-věda,  a compound consisting of the negative prefix *neand the verbal stem *věd‘to see > to know’.  However,  the late attestation of the word (20th  century) and instances of the initial cluster dnreduced to n(Dnemrak 1839, today Nemrak) suggest another Common Slavic  protoform underlying, *dьne-věda  ‘apparition in daylight’, a variant...

  19. 78 FR 74130 - Federal Reserve Policy on Payment System Risk; Procedures for Measuring Daylight Overdrafts

    Science.gov (United States)

    2013-12-10

    ... Banks, generally had multiple daily paper deposit deadlines and in which banks used airplanes and... electronically or in paper in Room MP-500 of the Board's Martin Building (20th and C Streets NW.) between 9:00 a... handle checks in paper form and do not reflect banks' widespread use of electronic check-processing...

  20. Integrated smart control of heating, cooling, ventilation, daylighting and electrical lighting in buildings

    NARCIS (Netherlands)

    Bakker, L.G.; Brouwer, A.H.M.; Babuska, R.

    1998-01-01

    The present energy consumption of European Buildings is higher than necessary, given the developments in control engineering. Optimization and integration of smart control into building systems can save substantial quantities of energy on a European scale while improving the standards for indoor

  1. Exposure to Non-Extreme Solar UV Daylight: Spectral Characterization, Effects on Skin and Photoprotection

    OpenAIRE

    Marionnet, Claire; Tricaud, Caroline; Bernerd, Fran?oise

    2014-01-01

    The link between chronic sun exposure of human skin and harmful clinical consequences such as photo-aging and skin cancers is now indisputable. These effects are mostly due to ultraviolet (UV) rays (UVA, 320–400 nm and UVB, 280–320 nm). The UVA/UVB ratio can vary with latitude, season, hour, meteorology and ozone layer, leading to different exposure conditions. Zenithal sun exposure (for example on a beach around noon under a clear sky) can rapidly induce visible and well-characterized clinic...

  2. Letting the daylight in : Reviewing the reviewers and other ways to maximize transparency in science

    NARCIS (Netherlands)

    Wicherts, J.M.; Kievit, R.A.; Bakker, M.; Borsboom, D.

    2012-01-01

    With the emergence of online publishing, opportunities to maximize transparency of scientific research have grown considerably. However, these possibilities are still only marginally used. We argue for the implementation of (1) peer-reviewed peer review, (2) transparent editorial hierarchies, and

  3. Daylight operation of a free space, entanglement-based quantum key distribution system

    Energy Technology Data Exchange (ETDEWEB)

    Peloso, Matthew P; Gerhardt, Ilja; Ho, Caleb; Lamas-Linares, AntIa; Kurtsiefer, Christian [Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore)], E-mail: christian.kurtsiefer@gmail.com

    2009-04-15

    Many quantum key distribution (QKD) implementations using a free space transmission path are restricted to operation at night time in order to distinguish the signal photons used for a secure key establishment from the background light. Here, we present a lean entanglement-based QKD system overcoming that limitation. By implementing spectral, spatial and temporal filtering techniques, we establish a secure key continuously over several days under varying light and weather conditions.

  4. Clear as daylight: analysis of diurnal raptor pellets for small mammal studies

    Directory of Open Access Journals (Sweden)

    Matos, M.

    2015-04-01

    Full Text Available Non–invasive approaches are increasingly investigated and applied in studies of small mammal assemblages because they are more cost–effective and bypass conservation and animal welfare issues. However, pellets of diurnal raptors have rarely been used for these purposes. We evaluated the potential of marsh harrier pellets (Circus aeruginosus as a non–invasive method to sample small mammal assemblages, by comparing the results with those of sampling using Sherman live–traps and pitfalls. The three methods were applied simultaneously in an agricultural–wetland complex in NW Portugal. Estimates of species richness, diversity, evenness, abundance, and proportion of each species within the assemblage showed significant differences between the three methods. Our results suggest that the use of marsh harrier pellets is more effective in inventorying small mammal species than either of the two kinds of traps, while also avoiding any involuntary fatalities associated with the sampling of small non–volant mammals. Moreover, the analysis of pellets was the most cost–effective method. Comparison of the two trapping methodologies showed involuntary fatalities were higher in pitfalls than in Sherman traps. We discuss the advantages and flaws of the three methods, both from technical and conservational perspectives.

  5. Lighting energy savings potential of split-pane electrochromic windows controlled for daylighting with visual comfort

    Energy Technology Data Exchange (ETDEWEB)

    Software, Anyhere; Fernandes, Luis; Lee, Eleanor; Ward, Greg

    2013-03-15

    A simulation study was conducted to evaluate lighting energy savings of split-pane electrochromic (EC) windows controlled to satisfy key visual comfort parameters. Using the Radiance lighting simulation software, interior illuminance and luminance levels were computed for a south-facing private office illuminated by a window split into two independently-controlled EC panes. The transmittance of these was optimized hourly for a workplane illuminance target while meeting visual comfort constraints, using a least-squares algorithm with linear inequality constraints. Blinds were successively deployed until visual comfort criteria were satisfied. The energy performance of electrochromics proved to be highly dependent on how blinds were controlled. With hourly blind position adjustments, electrochromics showed significantly higher (62percent and 53percent, respectively without and with overhang) lighting energy consumption than clear glass. With a control algorithm designed to better approximate realistic manual control by an occupant, electrochromics achieved significant savings (48percent and 37percent, respectively without and with overhang). In all cases, energy consumption decreased when the workplace illuminance target was increased. In addition, the fraction of time during which the occupant had an unobstructed view of the outside was significantly greater with electrochromics: 10 months out of the year versus a handful of days for the reference case.

  6. March 1, 2005 Daylight Fireball Over Galicia (NW of Spain) and Minho (N. Portugal)

    Czech Academy of Sciences Publication Activity Database

    Docobo, J. A.; Trigo-Rodríguez, J.M.; Borovička, Jiří; Tamazian, V.; Fernandes, V.A.; Llorca, J.

    2008-01-01

    Roč. 102, 1-4 (2008), s. 537-542 ISSN 0167-9295. [Meteoroids 2007. Barcelona, 11.06.2007-15.06.2007] Institutional research plan: CEZ:AV0Z10030501 Keywords : meteors * meteoroids Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.033, year: 2008

  7. Daylight artificial light and people in an office environment, overview of visual and biological responses

    NARCIS (Netherlands)

    Begemann, S.H.A.; Beld, van den G.J.; Tenner, A.D.

    1997-01-01

    Abstract Long-term behaviour/response of people has been studied in standard window zone offices during daytime working hours. Regular cell-offices were equipped with experimental lighting systems delivering lighting conditions that are known to influence human physiology. The results show that most

  8. Biomass loss and nutrient redistribution in an Indonesian Thalassia hemprichii seagrass bed following seasonal low tide exposure during daylight

    NARCIS (Netherlands)

    Stapel, J.; Manuntun, R.; Hemminga, M.A.

    1997-01-01

    The intertidal reef flat of Barang Lompo Island, Indonesia, is exposed to air for several hours per day on the days around spring tides. The time of exposure shows a seasonal pattern. In the period January-June, the reef flat only runs dry at night, whereas in the period July-December, exposure only

  9. Daylight and solar control in buildings. General evaluation and optimization of a new angle selective glazing facade

    Energy Technology Data Exchange (ETDEWEB)

    Frontini, Francesco

    2011-07-01

    Buildings account for almost 40% of the overall energy consumption in Europe. For the future energy scenarios, the building envelope, especially the facades, becomes really important as it provides the necessary area for the installation of PV modules or solar collectors to produce energy, using renewable energy sources. A new multifunctional building integrated photovoltaic (BIPV) glazed facade for this application is presented here. The new angle-selective see through facade combines four important tasks in one element: solar control, glare protection, visual contact and electricity generation. Mathematical analysis and complex simulations with the software Radiance are performed to optimize the geometry and to assess the visual impact and optical properties of the new window. In order to evaluate the impact of the new facade in building spaces a new method for modelling the total solar energy transmittance, in building energy simulations software, for complex glazing facades is presented. The new black-box-model (BBM) is implemented into ESP-r software and is validated. The BBM is used to assess the impact of modelling accurately the g-value of complex facade within building simulation. It is shown that the new method can significantly increase the accuracy of heating/cooling loads and room temperatures. (orig.)

  10. Pretreatment with 5-Fluorouracil Cream Enhances the Efficacy of Daylight-mediated Photodynamic Therapy for Actinic Keratosis

    DEFF Research Database (Denmark)

    Nissen, Christoffer V; Heerfordt, Ida Marie; Wiegell, Stine R

    2017-01-01

    The efficacy of photodynamic therapy (PDT) with methyl aminolevulinate is reduced when treating actinic keratosis (AK) on the extremities in comparison with the face and scalp. Studies indicate that PDT efficacy can be improved by combining PDT with other treatment modalities. This randomized intra...

  11. Continuous daylight in the high-Arctic summer supports high plankton respiration rates compared to those supported in the dark

    KAUST Repository

    Mesa, Elena; Delgado-Huertas, Antonio; Carrillo-de-Albornoz, Paloma; Garcí a-Corral, Lara S.; Sanz-Martí n, Marina; Wassmann, Paul; Reigstad, Marit; Sejr, Mikael; Dalsgaard, Tage; Duarte, Carlos M.

    2017-01-01

    Plankton respiration rate is a major component of global CO2 production and is forecasted to increase rapidly in the Arctic with warming. Yet, existing assessments in the Arctic evaluated plankton respiration in the dark. Evidence that plankton

  12. Modelling and Analysis of Daylight, Solar Heat Gains and Thermal Losses to Inform the Early Stage of the Architectural Process

    OpenAIRE

    Baker, Nicholas

    2017-01-01

    The EU building sector is a main contributor to greenhouse gas emissions, which need to be cut as part of the global response to anthropogenic climate change. This cut can be realised through improvements in building energy performance, such as optimisation of facade design. The early stage of the architectural process has been identified as the ideal time to implement such sustainable design choices. There is need for simple guidelines and tools to provide quantitative data to support these ...

  13. ERCB investigation report : Daylight Energy Amalgamation Co Ltd. sour gas release surface location 06-23-047-10W5M December 16, 2009

    Energy Technology Data Exchange (ETDEWEB)

    Temple, B.; Schlager, J.; Wilkes, J.; Saulnier, P.; Mayall, J.; Duben, A.; Ravensdale, C.

    2010-07-21

    This report discussed a sour gas release that occurred at a well located near the town of Lodgepole. The well had a hydrogen sulfide (H{sub 2}S) concentration of 29.19 per cent, with an emergency planning zone (EPZ) of 570 m. The owner of the well contacted stakeholders in the region, and road blocks were set up north of the well. Three mobile air monitoring units were dispatched to the site, and service contractors were hired to kill the well. The road blocks were removed after a review of the air monitoring data. Prior to the release, a heat tape assembly had been installed in the well as a result of ongoing hydrate formation problems. An investigation of the well after the release showed damage to the connectors in the heat tape assembly. A failure analysis showed that the damage was caused by excessive temperatures created by a short circuit in the wires located in each connector. The heat allowed downhole gas pressure to push the wire to the surface. Gas was released from the damaged assembly seal. An outline of all steps taken to address the emergency was provided. 4 figs.

  14. With building integrated photovoltaic in a daylight optimized passive house to energy autonomy; Mit gebaeudeintegrierter PV im tageslichtoptimierten Passivhaus zur bilanziellen Energieautarkie

    Energy Technology Data Exchange (ETDEWEB)

    Miloni, R.P. [Miloni Lichtplanung und Architektur, Hausen (Switzerland)

    2008-07-01

    With the introduction of a cost recovering energy feeding law, new possibilities open up for the building integration of photovoltaics and for the solar power generation at the ''Point of sale ''. Still, the appropriate Swiss market is marginal. Not all legal, technical and financial hurdles are removed. Here the photovoltaics with its building integration is in touch with an emotional factor of revaluation: An integration of photovoltaics adresses the building owner beyond their technical-economic value at a culturally abstract level - a wing of a butterfly oscillating in the sunlight also touches on a completely different level. Exactly the same the integration of photovoltaics makes the building to a unique piece of jewellery. In the pioneer phase of the photovoltaics market, architectonically successful integrations of photovoltaics succeeded in a break-through of the solar power generation. Photovoltaics at building coverings is more than a ''fashion '': it becomes a lever arm, with which the solarization of our society transports significant values. Apart from rational-technical considerations this effect has to be used to favour a broad application of photovoltaics with the building integration more purposefully.

  15. Study of the optical properties of the DF2000MA daylight film used in the XENON1T muon veto water tank

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, Diego [Institut fuer Physik, Johannes Gutenberg-Universitaet Mainz (Germany)

    2016-07-01

    XENON1T is the 3rd stage of a series of experiments performed by the XENON collaboration for the direct detection of dark matter candidates, such as WIMPs. Its projected spin-independent WIMP-nucleon elastic scattering cross-section entails an improvement of two orders of magnitude with respect to Xenon100 and requires, for a fiducial mass of the detector of about 1 ton liquid xenon, a similar reduction in background. In order to minimize the neutron background induced by cosmic ray muons, the XENON1T TPC is placed in the center of a 750 m{sup 3} water tank acting as an active Cherenkov muon veto, the walls of which are clad with the high reflective DF2000MA foil by 3M. The improved setup and results of a dedicated study of the reflective properties of the foil is presented, as well as a measurement of its possible wavelength shifting (WLS) properties. The analysis yields a specular reflectance of ∼ 100% for wavelengths larger than 400 nm, while ∼ 90% of the incoming light with wavelengths smaller than 370 nm is absorbed by the foil. The emission spectra of the WLS are dependent on the absorbed wavelength and show Gaussian shapes, with highest intensities at mean values of ∼ 450 nm emission wavelength.

  16. A methodological study of environmental simulation in architecture and engineering. Integrating daylight and thermal performance across the urban and building scales

    DEFF Research Database (Denmark)

    Sattrup, Peter Andreas; Strømann-Andersen, Jakob Bjørn

    2011-01-01

    This study presents a methodological and conceptual framework that allows for the integration and creation of knowledge across professional borders in the field of environmental simulation. The framework has been developed on the basis of interviews with leading international practitioners, key...... in pointing out the need for improving metrics, software and not least the performance of the built environment itself....

  17. 76 FR 64081 - National Advisory Council on Indian Education (NACIE)

    Science.gov (United States)

    2011-10-17

    ... Daylight Savings Time; 9 a.m. to 5 p.m. Pacific Daylight Saving Time. November 3, 2011--12 p.m. to 8 p.m. Eastern Daylight Savings Time; 9 a.m. to 5 p.m. Pacific Daylight Saving Time. Location: The Doubletree by... approximately 3 p.m.-5 p.m. Eastern Daylight Savings Time November 2, 2011. Those members of [[Page 64082

  18. Stability of MEH-PPV: poly{[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene]vinylene} in solutions exposed to air in the dark and at daylight at laboratory temperature

    Czech Academy of Sciences Publication Activity Database

    Bondarev, D.; Trhlíková, Olga; Sedláček, J.; Vohlídal, J.

    2014-01-01

    Roč. 110, December (2014), s. 129-136 ISSN 0141-3910 Institutional support: RVO:61389013 Keywords : aging * conjugated polymers * degradation Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.163, year: 2014

  19. Jaké jsou náklady a výnosy letního času?

    OpenAIRE

    Kožušková, Kateřina

    2011-01-01

    Daylight saving time (DST) was implemented with purpose to maximize use of daylight and thereby reduce electricity consumption used for lighting. This policy would primarily affect energetics, however its influence was shown in many other areas. The thesis contains general assumptions of daylight saving time impact on electricity consumption and the main goal of the thesis is to identify with the natural experiment whether the extension of daylight saving time till the end of October occuring...

  20. 76 FR 33745 - National Advisory Council on Indian Education (NACIE)

    Science.gov (United States)

    2011-06-09

    .... Eastern Daylight Savings Time. June 24, 2011--12 p.m. to 5 p.m. Eastern Daylight Savings Time. Location..., 2 p.m. to 5 p.m. Eastern Daylight Savings Time and June 24, 2011, 12 p.m. to 5 p.m. Eastern Daylight Savings Time. These discussions pertain solely to internal personnel rules and practices of an agency and...

  1. 76 FR 52567 - Drawbridge Operation Regulation; Bonfouca Bayou, Slidell, LA

    Science.gov (United States)

    2011-08-23

    ... in the mornings and later in the evenings during the months of daylight savings time. DATES: This... later in the mornings and later in the evenings during the months of daylight savings time from March 1... we extended the time for the bridge to open on signal to 9 p.m., during the months of daylight...

  2. Light and colours

    DEFF Research Database (Denmark)

    Volf, Carlo

    2011-01-01

    Often a dichotomy between daylight and artificial light is observed, often artificial lighting replaces daylight. In Denmark daylight is characterized partly by being "borrowed" half of the year, partly by having long transitions periods between the light and the dark (nautical and civil twilight......). For these reasons artificial lighting does not complement daylight but provides, coupled with the daylight, the total lighting in the indoor environment. Electric lighting is therefore ‐ in a complex interaction with the daylight ‐ of great importance for both our lighting and our wellbeing. Studying artificial...... lighting without studying daylight seem to be a common procedure of the practice of today in Denmark and other parts of the industrialized world. As a consequence of this artificial lighting suffers from a quantifying tyranny, a tyranny where the quality of light is measured in quantities. This procedure...

  3. Computer- og dagslysstyret kunstlys på Rigshosptalet

    DEFF Research Database (Denmark)

    Volf, Carlo

    2008-01-01

    Light is, without doubt, extremely important for the wellbeing of people. Yet, at many workplaces only small amounts of daylight enter. This is especially true for hospitals, where the lack of daylight in corridors affects both patients and staff. Hospital corridors have become much more than...... transport areas, and the lack of daylight in corridors combined with deficient lighting have consequences for health and working environment....

  4. 77 FR 23230 - National Advisory Council on Indian Education (NACIE)

    Science.gov (United States)

    2012-04-18

    ... Committee Act. Date and Time: May 2-3, 2012; May 2, 2012--8 a.m.-5 p.m. Eastern Daylight Savings Time. May 3, 2012--8 a.m.-5 p.m. Eastern Daylight Savings Time. Location: Washington, DC--Details about the meeting...., Washington, DC 20202. Monday-Friday, 8:30 a.m.- 5 p.m. Eastern Daylight Time. Electronic Access to This...

  5. 76 FR 18539 - National Advisory Council on Indian Education (NACIE)

    Science.gov (United States)

    2011-04-04

    ... Advisory Committee Act. DATE AND TIME: April 18-19, 2011; April 18, 2011--9:30 a.m.-5 p.m. Eastern Daylight Savings Time. April 19, 2011--9:00 a.m.-5 p.m. Eastern Daylight Savings Time. Location: Holiday Inn... public comment at approximately 1 p.m.-2:30 p.m. Eastern Daylight Savings Time April 19, 2011. Each...

  6. The Experience of Dynamic Lighting

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Kristensen, Ole

    2017-01-01

    of daylight openings and the experience of spatial form. However, current developments in LED light sources (light emitting diodes) and adaptive software control systems allow for an enhanced correlation between daylight and artificial lighting, where the variations of the daylight are dynamically...... supplemented by variations in the artificial lighting. The suggestion is to develop a particular type of Observational Instrument that situates detailed experiential investigations into the design potentials of integration of natural and artificial lighting, and thereby to enable differentiated dynamic...

  7. 75 FR 56562 - Proposed Information Collection Request Submitted for Public Comment and Recommendations; Slope...

    Science.gov (United States)

    2010-09-16

    ... by midnight Eastern Daylight Savings Time on November 15, 2010. ADDRESSES: Comments must clearly be... format, reporting burden (time and financial resources) is minimized, collection instruments are clearly...

  8. Exemplary.... Nine examples to save energy and cost by intelligent engineering; Zur Nachahmung empfohlen.... Neun Faelle, in denen mit intelligenter Technik Energie und Kosten gespart werden

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Contents: Daylighting and energy management, light offices by daylight guidance, fresh air after demand by frequency converters, saving heating cost by intelligent control, optimized lighting systems in schools, fresh air from an external provider and compressed air monitoring in a mine. (GL)

  9. Appraisal of the Visual Environment in an Industrial Factory: a Case Study in Subtropical Climates

    Directory of Open Access Journals (Sweden)

    Kieu Pham

    2016-12-01

    Full Text Available The physiological and psychological benefits of daylighting for office occupants have been well explored. Current research usually focuses on visual comfort in office buildings. However, there is limited knowledge about daylight quality in industrial work environments. In Australia, most industrial buildings are built from standard factory structures that employ daylight from skylights and large door openings, with little consideration to daylighting design strategies and visual comfort. In bright sky conditions as those present in Australia, large openings can become a source of visual discomfort. It is important to understand how workers perceive the luminous environment in this type of work setting. This research explored the perception of daylighting in an industrial work environment. Qualitative measures (questionnaires, interviews, and observational mapping and quantitative measures (physical data were collected over a four week period to examine the type of visual comfort perceived by industrial workers. The results suggests that the desirability to have windows and to have access to a view were important features in this work setting. Access for task lighting and reports of uneven daylighting were indicative to the varying levels of illuminance under intermediate sky conditions. This was reflected in the daylight glare index results and comparisons to the background luminance and glare source luminance, indicating that adaptation may be the cause of responses to daylighting being uneven. The results suggests a need for further research into the quality of the luminous environment in industrial work settings.

  10. How to Frame Universal Workspace Lighting

    DEFF Research Database (Denmark)

    Mathiasen, Nanet; Frandsen, Anne Kathrine

    2016-01-01

    ; regardless of disability everybody should be able to move around in the house and work in any of the offices. One, of many ambitions, was to design a functional and effective lighting scheme using as much daylight as possible, and integrating the artificial lighting design and daylight design. The lighting...

  11. 78 FR 25426 - Fisheries of the Exclusive Economic Zone Off Alaska; American Fisheries Act, Amendment 80 Program...

    Science.gov (United States)

    2013-05-01

    ..., from 10 a.m. to 2 p.m. Alaska daylight savings time. The second workshop will be held on Tuesday, May 14, 2013, from 1 p.m. to 4 p.m. Pacific daylight savings time. ADDRESSES: The first workshop will be...

  12. 77 FR 53187 - Advisory Council on Dependents' Education; Notice of Open Meeting

    Science.gov (United States)

    2012-08-31

    ... Daylight Savings Time (EDST); Stuttgart and Wiesbaden, Germany, from 2 p.m. to 6 p.m., Central European Summer Time (CEST); Okinawa, Japan, from 9 p.m. to 1 a.m., Japan Standard Time (JST); Honolulu, Hawaii... 12 p.m., Eastern Daylight Savings Time (EDST). ADDRESSES: 4800 Mark Center Drive, Alexandria, VA...

  13. 76 FR 38638 - Commerce Spectrum Management Advisory Committee Meeting

    Science.gov (United States)

    2011-07-01

    ... Daylight Savings Time. ADDRESSES: The meeting will be held at the Institute for Telecommunication Sciences... the meeting. Time and Date: The meeting will be held on July 27, 2011 from 1 p.m. to 4 p.m., Mountain Daylight Savings Time. The times and the agenda topics are subject to change. The meeting may be webcast or...

  14. 76 FR 24870 - National Advisory Council on Indian Education (NACIE) Meeting

    Science.gov (United States)

    2011-05-03

    ... Advisory Committee Act. Date and Time: May 18, 2011; May 18, 2011--2 p.m.-5 p.m. Eastern Daylight Savings Time Location: The closed meeting will be conducted via conference call with NACIE members... Avenue, SW., Washington, DC 20202. Monday-Friday, 8:30 a.m.-5 p.m. Eastern Daylight Time. Electronic...

  15. 77 FR 39516 - Notice of a Public Meeting of the Advisory Committee on Apprenticeship (ACA)

    Science.gov (United States)

    2012-07-03

    ... ACA are open to the public. Time and Date: The meeting will begin at approximately 1:30 p.m. Eastern Daylight Savings Time on Wednesday, August 1, 2012, and continues until approximately 5:00 p.m. The meeting will reconvene on Thursday, August 2, 2012, at approximately 9:00 a.m. Eastern Daylight Savings Time...

  16. 48 CFR 1252.236-70 - Special precautions for work at operating airports.

    Science.gov (United States)

    2010-10-01

    ... working condition at all times other than daylight hours. The hour of beginning and the hour of ending of... shall be marked by yellow flags during daylight hours and by red lights at other times. The red lights... less than 100 watts intensity placed and supported as required. All other construction markings on...

  17. Lighting and energy performance for an office using high frequency dimming controls

    International Nuclear Information System (INIS)

    Li, Danny H.W.; Lam, Tony N.T.; Wong, S.L.

    2006-01-01

    Artificial lighting is one of the major electricity consuming items in many non-domestic buildings. Recently, there has been an increasing interest in incorporating daylight in architectural and building designs to reduce the electricity use and enhance greener building developments. This paper presents field measurements for a fully air conditioned open plan office using a photoelectric dimming system. Electric lighting load, indoor illuminance levels and daylight availability were systematically measured and analyzed. The general features and characteristics of the results such as electric lighting energy savings and transmitted daylight illuminance in the forms of frequency distributions and cumulative frequency distributions are presented. Daylighting theories and regression models have been developed and discussed. It has been found that energy savings in electric lighting were over 30% using the high frequency dimming controls. The results from the study would be useful and applicable to other office spaces with similar architectural layouts and daylight linked lighting control systems

  18. Evaluation of Suitability of a Parametrically Controlled Louvers for Various Orientations throughout a Year Comparing to an Existing Case

    Directory of Open Access Journals (Sweden)

    Ahmad Eltaweel

    2017-11-01

    Full Text Available Nowadays, daylighting systems and shading devices are controlled automatically to achieve their optimum benefits. For more comprehensive accuracy, parametric control was recently used to manage complex parameters with more accuracy. Such a system was proposed and investigated in a previous research to provide steadier and more uniform daylight illuminance during the day and reduce more than 80% of the electricity consumption. This study is examining the daylighting performance by using the parametric system in different orientations and comparing with the conventional ones. Furthermore, the study will evaluate the suitability of the parametric system throughout the year during the working hours in a typical office room.

  19. Maximizing the lightshelf performance by interaction between lightshelf geometries and a curved ceiling

    Energy Technology Data Exchange (ETDEWEB)

    Freewan, Ahmed A. [Jordan University of Science and Technology, Irbid 22110 (Jordan)

    2010-08-15

    The interaction between different lightshelf geometries combined with a curved ceiling was investigated using radiance to maximize the daylight performance of a lightshelf. Two main performance parameters were investigated; illuminance level and distribution uniformity in a large space located in a sub-tropical climate region like Jordan. It was found that a curved lightshelf could improve the daylight level by 10% compared to a horizontal lightshelf. A curved lightshelf help to bounce more daylight deep into a space thus improve the illuminance level and uniformity level. The best lightshelf shapes found are curved and chamfered lightshelves compared to horizontal lightshelves. (author)

  20. Melatonin in sleepless children : everything has a rhythm?

    NARCIS (Netherlands)

    van Geijlswijk, I.M.

    2011-01-01

    Every living organism has an biological clock regulating endogenous melatonin production, synchronized by exogenous impulses like daylight, temperature and feeding. Inappropriately applied bright light disturbs this melatonin rhythm. Some large swine producers apply artificial light three times a

  1. 78 FR 39326 - Notice Pursuant To the National Cooperative Research and Production Act of 1993-Opendaylight...

    Science.gov (United States)

    2013-07-01

    ... Clara, CA; Cyan Inc., Petaluma, CA; Dell Inc., Round Rock, TX; Ericsson Inc., San Jose, CA; Fujitsu...Daylight's planned activity is to (a) Advance the creation, evolution, promotion, and support of an open...

  2. Enablers to Ensure a Successful Force Centric Logistics Enterprise

    National Research Council Canada - National Science Library

    Eaton, Donald R

    2004-01-01

    There is an ongoing logistics management revolution in the Department of Defense that is taking weapons systems life-cycle support from the shadow of acquisition into the daylight of a highly focused...

  3. Compact turbidity meter

    Science.gov (United States)

    Hirschberg, J. G.

    1979-01-01

    Proposed monitor that detects back-reflected infrared radiation makes in situ turbidity measurements of lakes, streams, and other bodies of water. Monitor is compact, works well in daylight as at night, and is easily operated in rough seas.

  4. 76 FR 21705 - Fisheries of the Exclusive Economic Zone Off Alaska; Catch Accounting in the Longline Catcher...

    Science.gov (United States)

    2011-04-18

    ... p.m. Pacific daylight savings time. ADDRESSES: The workshop will be held at the Swedish Cultural Center, 1920 Dexter Avenue, N., Seattle, WA 98109. Directions to the Swedish Cultural Center are on its...

  5. Pop / Tõnu Kaalep

    Index Scriptorium Estoniae

    Kaalep, Tõnu, 1966-2018

    2007-01-01

    Heliplaatidest: Richard Hawley "Lady's Bridge", Donavon Frankenreiter "Recycled Recipes", Black Strobe "Burn Your Own Church", Killswitch Engage "As Daylight Dies", Andre 3000 "Class of 3000: Music volume one", Biffy Clyro "Puzzle", Mutematch "Mutematch"

  6. How Can a Lighting Designer Use Light in Buildings For Well-Being? - 'Presented as invited speaker'

    DEFF Research Database (Denmark)

    Christoffersen, Jens

    design. Summary: Adequate lighting, both natural and artificial, is important as part of a person's well-being. A description of a person's well-being may be context-specific depending on the building design and include a number of parameters such as daylight and sunlight penetration, window views...... and content of view, enclosed or open space, crowding, visual and acoustical privacy, personal control of ambient conditions etc. Successful daylighting requires trade-offs and optimisation between competing design aspects by skilful integration of the facade layout with the space configuration and the choice...... of lighting system used.  Surveys consistently show that people prefer daylight over electric light, a desire for windows and view is well-established, and daylight as primary source is believed to be more healthful. Also, work spaces often consist of changing visual tasks, and thereby different lighting...

  7. Travelers' Health: Injuries and Safety

    Science.gov (United States)

    ... Safety Road Safety - 8 Steps MERS Health Advisory poster MERS Pictogram CDC Guide for Healthy Travel Website ... possible, fly on larger planes (>30 seats), in good weather, during the daylight hours, and with experienced ...

  8. 78 FR 7411 - Notice of Public Hearing and Request for Comments on Matters Related to the Harmonization of...

    Science.gov (United States)

    2013-02-01

    ... hearing will be held on March 21, 2013, beginning at 8:30 a.m. Eastern Daylight Time (EDT) and ending at... present. Based on the requests received, an agenda of scheduled testimony will be sent to testifying...

  9. Plaadid / Heili Vaus-Tamm

    Index Scriptorium Estoniae

    Vaus-Tamm, Heili, 1961-

    2003-01-01

    Uutest plaatidest The Dowland Project "Care-charming sleep John Potter", Clem Snide "Soft Spot", Deep Purple " Bananas", Don Johnson Big Band "Breaking Daylight", Duetto "Marcelo Alvarez, Salvatore Licitra", Sting "Sacred Love", Travis "12 Memories"

  10. 75 FR 43208 - Withdrawal of Regulatory Guide 5.17

    Science.gov (United States)

    2010-07-23

    ... the vehicles under daylight conditions from the air in clear weather at 1,000 feet above ground level... Transportation (DOT) regulations 49 CFR parts 172 through 180. These DOT regulations specify the shape, color...

  11. 75 FR 56560 - Proposed Information Collection Request Submitted for Public Comment and Recommendations; Health...

    Science.gov (United States)

    2010-09-16

    ... be received by midnight Eastern Daylight Savings Time on November 15, 2010. ADDRESSES: Comments must... to assure that requested data can be provided in the desired format, reporting burden (time and...

  12. 75 FR 36122 - Proposed Information Collection Request Submitted for Public Comment and Recommendations...

    Science.gov (United States)

    2010-06-24

    ... midnight Eastern Daylight Savings Time on August 23, 2010. ADDRESSES: Comments must clearly be identified... program helps to ensure that requested data can be provided in the desired format, reporting burden (time...

  13. 76 FR 18467 - Pattern of Violations

    Science.gov (United States)

    2011-04-04

    ... Eastern Daylight Savings Time on April 18, 2011. ADDRESSES: Submit comments by any of the following... proposed rule addressing Pattern of Violations (POV). This extension gives commenters additional time to...

  14. 75 FR 18888 - Mine Rescue Teams and Arrangements for Emergency Medical Assistance and Transportation for...

    Science.gov (United States)

    2010-04-13

    ...). DATES: All comments must be received by midnight Eastern Daylight Savings Time on June 14, 2010... requested data can be provided in the desired format, reporting burden (time and financial resources) is...

  15. 17 CFR 10.4 - Business address; hours.

    Science.gov (United States)

    2010-04-01

    ... legal public holidays from 8:15 a.m. to 4:45 p.m., eastern standard time or eastern daylight savings time, whichever is currently in effect in Washington, DC. If Commission personnel are present in the...

  16. Plaadid / Valner Valme

    Index Scriptorium Estoniae

    Valme, Valner, 1970-

    2003-01-01

    Uutest plaatidest Chingy "Jackpot", Don Johnson Big Band "Breaking Daylight", Mars Volta "De-loused In The Comatorium", Ella Fitzgerald "Sings Sweet Songs For Swingers", Queen "Live At Wembley 86", Iron Maiden "Dance Of Death"

  17. Genetics Home Reference: bradyopsia

    Science.gov (United States)

    ... such as when walking out of a darkened movie theater into daylight. Their eyes also have trouble ... Robson AG, Holder GE. Pathognomonic (diagnostic) ERGs. A review and update. Retina. 2013 Jan;33(1):5- ...

  18. ATBUJET VOLUME 8 NO. 2. PDF

    African Journals Online (AJOL)

    Ayodele Azeez A

    Recommendation is that, building projects for low and middle-income earners should ... Development later included .... Elsewhere in Malaysia, ... centre for economic activities in Nigeria, and .... adequacy of daylight distribution in flats, the.

  19. Variation of outdoor illumination as a function of solar elevation and light pollution.

    Science.gov (United States)

    Spitschan, Manuel; Aguirre, Geoffrey K; Brainard, David H; Sweeney, Alison M

    2016-06-07

    The illumination of the environment undergoes both intensity and spectral changes during the 24 h cycle of a day. Daylight spectral power distributions are well described by low-dimensional models such as the CIE (Commission Internationale de l'Éclairage) daylight model, but the performance of this model in non-daylight regimes is not characterised. We measured downwelling spectral irradiance across multiple days in two locations in North America: One rural location (Cherry Springs State Park, PA) with minimal anthropogenic light sources, and one city location (Philadelphia, PA). We characterise the spectral, intensity and colour changes and extend the existing CIE model for daylight to capture twilight components and the spectrum of the night sky.

  20. Sleep Patterns of Naval Aviation Personnel Conducting Mine Hunting Operations

    National Research Council Canada - National Science Library

    Solberg, Bennett J

    2006-01-01

    ... to daylight transition result in a myriad of physiological and psychological degradations (Helmreich 2000). Fatigue affects human performance adversely resulting in predictable changes not only on the individual level but also on the system as a whole...

  1. Solar Shading in Low Energy Office Buildings - Design Strategy and User Perception

    Directory of Open Access Journals (Sweden)

    Steinar Grynning

    2017-06-01

    Full Text Available The objective of this paper is to investigate the visual comfort and quality of daylight in modern office buildings in the Nordic climate. A study of various daylight-related aspects and qualities was carried out for three different office buildings, using a combination of quantitative and qualitative methods. The focus was on a combination of user perception of daylight quality and assessment of the daylight amount and quality, by using the daylight factor (DF and useful daylight illuminance parameters. Previous studies and experiences from construction examples indicate that users, in general, complain about lack of manual control of systems and too low daylight levels, even if the requirements in the building codes are satisfied. Furthermore, they complain about control algorithms of the shading devices, which cause undesired automatic opening and closure of such devices. Thus, causing disturbances and irritation amongst the users. Hence, interviews with key personnel in a modern and architecturally acclaimed office building were carried out in addition to an in-depth analysis of previous surveys of a zero-energy office building. It was found that automatic moveable shading can be regarded as a source of discomfort. This is due to the lack of manual-control override possibilities, which causes disturbances due to the system moving up and down. In one of the offices, the users disabled the exterior shading system. However, the external fixed shading and the internal manually operated roller blinds were found to be satisfactory. The results from a previous study showed that the users in the Marche building are in general satisfied with the daylight. One of the main reasons for this, according to the users, is that they have manual control of the shading system. Manual control of the shading systems is preferred by users in the office buildings studied. Daylight simulations showed that the external fixed shading system combined with internal

  2. The effect of short exposure to coloured light on thermal perception: a study using Virtual Reality

    OpenAIRE

    Chinazzo, Giorgia; Chamilothori, Kynthia; Wienold, Jan; Andersen, Marilyne

    2017-01-01

    This study investigates the effect of short exposure to coloured light on thermal perception. To give the impression of natural daylight passing through coloured filters, but avoiding the drawbacks of conducting an experiment with daylight, continuously changing due to daily and seasonal variations, and to weather conditions, we investigate the use of Virtual Reality as a means to control the visual conditions, creating a hybrid environment with thermal and visual stimuli from the real and vi...

  3. 75 FR 60492 - The Future of Aviation Advisory Committee (FAAC) Subcommittee on Competitiveness and Viability...

    Science.gov (United States)

    2010-09-30

    ... of the global economy. The Subcommittee on Competitiveness and Viability is charged with examining..., from 10 a.m. to 2:30 p.m. Mountain Daylight Time. ADDRESSES: The meeting will be held in the New Press... taking place on October 15, 2010, at 10 a.m. to 2:30 p.m. Mountain Daylight Time, in the New Press Room...

  4. Changes in Sunlight and Outdoor Thermal Environment Conditions Based on the Layout Plan of Flat Type Apartment Houses

    OpenAIRE

    Jung, Sukjin; Yoon, Seonghwan

    2015-01-01

    Economic growths lead to population increases in large cities. This has brought about the growing necessity for apartment housing which has resulted in higher density populations living in high-rise apartment complexes. Therefore, the urban microclimate is aggravated due to the increasing ratio of artificial coverage and substandard daylight availability. To achieve a comfortable living environment and improve urban microclimates, a process considering the daylight availability and the outdo...

  5. Ambient Air Conditions and Variation in Urban Trail Use

    OpenAIRE

    Holmes, Ann M.; Lindsey, Greg; Qiu, Chenchen

    2009-01-01

    This study examines the effect of air quality and administrative policies on use of urban trails in Indianapolis, IN. Attention is focused on two policy variables: (1) issuance of air pollution advisories and (2) the adoption of Daylight Savings Time. Results suggest that while trail use varies with air quality, current public advisories regarding air pollution may be of limited effectiveness in reducing trail users’ exposures to hazardous pollutants. In contrast, the adoption of Daylight Sav...

  6. 77 FR 62498 - Advisory Council on Dependents' Education; Meeting Cancellation Notice and Open Meeting Notice

    Science.gov (United States)

    2012-10-15

    ..., October 16, 2012, from 8:00 a.m. to 12:00 p.m. Eastern Daylight Savings Time; Stuttgart and Wiesbaden...-Aleutian Standard Time (H-AST); Peachtree City, Georgia, from 8:00 a.m. to 12:00 p.m., Eastern Daylight Savings Time (EDST) has been cancelled. Under the provisions of the Federal Advisory Committee Act of 1972...

  7. Šetří letní čas energii?: Meta analýza

    OpenAIRE

    Herman, Dominik

    2015-01-01

    Daylight saving time energy savings have always represented a contentious topic requiring empirical evidence for, or against. Unfortunately, as the conclusions are miscellaneous-without an evident pattern of heterogeneity occurrence-insisting on particular case studies and narrative literature reviews seems to be insufficient. In this thesis, set of various studies concerning the effect of daylight saving time on energy savings is examined through meta-regression analysis to provide an accura...

  8. Light and energy and architecture. Potentials in transparent solar cells; Lys og energi og arkitektur. Potentialer i transparente solceller

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Ellen Kathrine; Hilberth, T.R.; Munk, L.

    2008-04-15

    This publication aims to inspire and challenge to: 1) transform energy technology to architectural potentials, 2) introduce visions about daylight's potential into the energy debate, and 3) develop new strategies for interdisciplinary collaboration. In addition to converting solar energy to electricity transparent solar cells can be integrated into glass facades and thereby regulate indoor climate and daylight intake. Furthermore solar cells can contribute new visual dimensions. (BA)

  9. Lighting preferences in individual offices

    Directory of Open Access Journals (Sweden)

    João Roberto Gomes de Faria

    Full Text Available Abstract Workplaces with good daylighting offer visual comfort to users, give them a series of physiological and psychological benefits and allow good performance of visual activities, besides saving energy. However, this solution is not always adopted: lighting type preferences involve many variables besides the availability of daylight. This paper explores a case study through the analysis of questionnaire answers and computer simulations of a series of metrics related to quality of lighting with the aim of finding explanations for the lighting preferences of individual office users. The results show that, although the offices present good daylighting conditions and no glare potential, and users are satisfied with daylighting, these parameters are not sufficient to explain the predominant lighting preferences. The findings have also shown that there is no consensus about which parameters potentially cause visual comfort, while the parameters that cause discomfort are clearly identified. In addition, in this study, 49% of the preference for mixed lighting (daylight plus electrical light can be explained by the fact that mixed lighting produces better modeling than daylighting alone.

  10. Colour Model for Outdoor Machine Vision for Tropical Regions and its Comparison with the CIE Model

    Energy Technology Data Exchange (ETDEWEB)

    Sahragard, Nasrolah; Ramli, Abdul Rahman B [Institute of Advanced Technology, Universiti Putra Malaysia 43400 Serdang, Selangor (Malaysia); Marhaban, Mohammad Hamiruce [Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia 43400 Serdang, Selangor (Malaysia); Mansor, Shattri B, E-mail: sahragard@yahoo.com [Department of Civil Engineering, Faculty of Engineering, Universiti Putra Malaysia 43400 Serdang, Selangor (Malaysia)

    2011-02-15

    Accurate modeling of daylight and surface reflectance are very useful for most outdoor machine vision applications specifically those which are based on color recognition. Existing daylight CIE model has drawbacks that limit its ability to predict the color of incident light. These limitations include lack of considering ambient light, effects of light reflected off the ground, and context specific information. Previously developed color model is only tested for a few geographical places in North America and its accountability is under question for other places in the world. Besides, existing surface reflectance models are not easily applied to outdoor images. A reflectance model with combined diffuse and specular reflection in normalized HSV color space could be used to predict color. In this paper, a new daylight color model showing the color of daylight for a broad range of sky conditions is developed which will suit weather conditions of tropical places such as Malaysia. A comparison of this daylight color model and daylight CIE model will be discussed. The colors of matte and specular surfaces have been estimated by use of the developed color model and surface reflection function in this paper. The results are shown to be highly reliable.

  11. Implications of longitude and latitude on the size of solar-powered UAV

    International Nuclear Information System (INIS)

    Rajendran, Parvathy; Smith, Howard

    2015-01-01

    Highlights: • We studied solar irradiance and daylight implication on solar-powered UAV design. • We explored for perpetual UAV flight for 12 cities around the world. • All year round solar-powered UAV operation possible for cities near equatorial line. • Cities in latitudes of ±35° are the optimal for solar-powered UAV. • Longitudinal coordinates and elevation have a minor effect on UAV design. - Abstract: The implication of solar irradiance and daylight duration on the design of a small solar-powered unmanned aerial vehicle (UAV) that is capable of operating perpetually in various cities around the world was investigated. Solar data in 2013 on 12 cities distributed around the world was collected. The effects of the available solar irradiance and daylight of the city on the maximum take-off weight and wing span of a small solar-powered UAV were studied. The analysis indicates that daylight duration is as important as the available solar irradiance to the performance of the solar-powered UAV. Longitudinal coordinates and elevation have a minor effect on the estimation of daylight duration. Areas considerably high in solar irradiance and daylight duration are more conducive to the effective performance of solar-powered UAVs than other areas. Therefore, cities closer to the equator have an advantage in utilizing solar-powered UAVs; where smaller and lighter solar-powered UAV can be designed

  12. Colour Model for Outdoor Machine Vision for Tropical Regions and its Comparison with the CIE Model

    Science.gov (United States)

    Sahragard, Nasrolah; Ramli, Abdul Rahman B.; Hamiruce Marhaban, Mohammad; Mansor, Shattri B.

    2011-02-01

    Accurate modeling of daylight and surface reflectance are very useful for most outdoor machine vision applications specifically those which are based on color recognition. Existing daylight CIE model has drawbacks that limit its ability to predict the color of incident light. These limitations include lack of considering ambient light, effects of light reflected off the ground, and context specific information. Previously developed color model is only tested for a few geographical places in North America and its accountability is under question for other places in the world. Besides, existing surface reflectance models are not easily applied to outdoor images. A reflectance model with combined diffuse and specular reflection in normalized HSV color space could be used to predict color. In this paper, a new daylight color model showing the color of daylight for a broad range of sky conditions is developed which will suit weather conditions of tropical places such as Malaysia. A comparison of this daylight color model and daylight CIE model will be discussed. The colors of matte and specular surfaces have been estimated by use of the developed color model and surface reflection function in this paper. The results are shown to be highly reliable.

  13. Colour Model for Outdoor Machine Vision for Tropical Regions and its Comparison with the CIE Model

    International Nuclear Information System (INIS)

    Sahragard, Nasrolah; Ramli, Abdul Rahman B; Marhaban, Mohammad Hamiruce; Mansor, Shattri B

    2011-01-01

    Accurate modeling of daylight and surface reflectance are very useful for most outdoor machine vision applications specifically those which are based on color recognition. Existing daylight CIE model has drawbacks that limit its ability to predict the color of incident light. These limitations include lack of considering ambient light, effects of light reflected off the ground, and context specific information. Previously developed color model is only tested for a few geographical places in North America and its accountability is under question for other places in the world. Besides, existing surface reflectance models are not easily applied to outdoor images. A reflectance model with combined diffuse and specular reflection in normalized HSV color space could be used to predict color. In this paper, a new daylight color model showing the color of daylight for a broad range of sky conditions is developed which will suit weather conditions of tropical places such as Malaysia. A comparison of this daylight color model and daylight CIE model will be discussed. The colors of matte and specular surfaces have been estimated by use of the developed color model and surface reflection function in this paper. The results are shown to be highly reliable.

  14. Light-zone(s: as Concept and Tool

    Directory of Open Access Journals (Sweden)

    Merete Madsen

    2012-11-01

    Full Text Available Daylight is essential to the experience of an architectural space. Nevertheless, amongst the handful of predominantly scientific methods available to assess daylight in architecture, there are only a few considering the spatial and form-giving characteristics of daylight. This paper investigates light-zone(s as concept and tool, which can be taken as a point of departure for a new method to perceive, consider and analyse daylight in architecture. As concept, light-zone(s are areas, fields or zones of light. It is a way of considering a space’s daylight as (forms of bubbles or spheres of light, which as light-zones can be compressed, expanded, combined, exploded, etc., all according to the character of 'the meeting' between the light-zone(s and the space itself (inclusive of the space’scontent. Thus, the daylight in a space can be regarded asa composition of light-zones.As tool, light-zone(s are (spatial groupings of the lightingvariables (intensity, direction, distribution and colour, whichare significant to the space and form-giving characteristicsof light. That is to say, the light-zone(s tool is the point ofdeparture for a method of creating a spatial ‘grasp’ on daylighting variables in a given space. The relation between the light-zone(s concept and tool respectively can be described as follows: On the one level light-zone(s can be explored as an architectural idea or notion, thus belonging more to the field of architectural theory. On another more practice-driven level, light-zone(s can be articulated and specified in relation to lighting technology.

  15. Correlation of classroom typologies to lighting energy performance of academic building in warm-humid climate (case study: ITS Campus Sukolilo Surabaya)

    Science.gov (United States)

    Ekasiwi, S. N. N.; Antaryama, I. G. N.; Krisdianto, J.; Ulum, M. S.

    2018-03-01

    Classrooms in educational buildings require certain lighting requirements to serve teaching and learning activities during daytime. The most typical design is double sided opening in order to get good daylight distribution in the classroom. Using artificial light is essential to contribute the worse daylight condition. A short observation indicates that during the lecture time the light turned on, even in the daytime. That might result in wasting electrical energy. The aim of the study is to examine the type of classroom, which perform comfortable lighting environment as well as saving energy. This paper reports preliminary results of the study obtained from field observation and measurements. The use of energy and usage pattern of artificial lighting during the lecture is recorded and then the data evaluated to see the suitability of existing energy use to building energy standards. The daylighting design aspects have to be the first consideration. However, the similarity in WWR of the classroom, the Daylight Factor (DF) may differ. It depends on the room depth. The similarity of the increase of WWR and Ratio of openings to floor area do not directly correspond to the increase of DF. The outdoor condition of larger daylight access and the room depth are the influencing factors. Despite the similarity of physical type, usage pattern of the classroom imply the use of electrical energy for lighting. The results indicate the factors influencing lighting energy performance in correlation to their typologies

  16. Annual Performance Assessment of Complex Fenestration Systems in Sunny Climates Using Advanced Computer Simulations

    Directory of Open Access Journals (Sweden)

    Chantal Basurto

    2015-12-01

    Full Text Available Complex Fenestration Systems (CFS are advanced daylighting systems that are placed on the upper part of a window to improve the indoor daylight distribution within rooms. Due to their double function of daylight redirection and solar protection, they are considered as a solution to mitigate the unfavorable effects due to the admission of direct sunlight in buildings located in prevailing sunny climates (risk of glare and overheating. Accordingly, an adequate assessment of their performance should include an annual evaluation of the main aspects relevant to the use of daylight in such regions: the indoor illuminance distribution, thermal comfort, and visual comfort of the occupant’s. Such evaluation is possible with the use of computer simulations combined with the bi-directional scattering distribution function (BSDF data of these systems. This study explores the use of available methods to assess the visible and thermal annual performance of five different CFS using advanced computer simulations. To achieve results, an on-site daylight monitoring was carried out in a building located in a predominantly sunny climate location, and the collected data was used to create and calibrate a virtual model used to carry-out the simulations. The results can be employed to select the CFS, which improves visual and thermal interior environment for the occupants.

  17. Literature Review of the Effects of Natural Light on Building Occupants

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, L.; Torcellini, P.

    2002-07-01

    This paper presents summary findings from a literature search of the term ''daylighting''-using natural light in a building to offset or replace electric lighting. According to the Department of Energy's Office of Building Technology, State and Community Programs 2000 BTS Core Databook, in 1998, commercial buildings consumed 32% of the total electricity in the United States, of which more than one-third went to lighting. Using daylighting systems and turning off the lights will help reduce this energy load. Electrical lighting adds to both the electrical and cooling loads in a commercial building. Utility costs can be decreased when daylighting is properly designed to replace electrical lighting. Along with the importance of energy savings, studies have demonstrated the non-energy-related benefits of daylighting. We compiled the data from books, periodicals, Internet articles, and interviews. The books, periodicals, and Internet articles provided the background information used to identify the main subjects of the paper. The interviews provided us with details related to specific buildings and companies that have integrated daylighting into their buildings.

  18. PERFORMANCE EVALUATION OF SDN CONTROLLERS: FLOODLIGHT AND OPENDAYLIGHT

    Directory of Open Access Journals (Sweden)

    Shiva Rowshanrad

    2016-11-01

    Full Text Available Software Defined Network is new network architecture. One of its components is the controller, which is the intelligent part of SDN. Many controllers such as Floodlight, Open Daylight, Maestro, NOX, POX and many others are released. The question is which controller can perform better in which situations. Many works were done to compare controllers regarding architecture, efficiency and controllers’ features. In this paper, two of the most popular controllers, Floodlight and OpenDaylight are compared in terms of Network QoS parameters such as delay and loss in different topologies and network loads. This paper can help researchers to choose the best controller in different use cases such as clouds and multimedia. The results with 95% confidence interval show that OpenDaylight outperforms Floodlight in low loaded networks and also for tree topology in mid loaded networks in terms of latency. Floodlight can outperform OpenDaylight in heavy loaded networks for tree topology in terms of packet loss and in linear topology in terms of latency. There is no significant difference in performance of Floodlight and OpenDaylight controllers in other cases.

  19. Energy-oriented modernisation and energy-economic extension of prefabricated school buildings of type FKZ 0329224 C; Energetische Sanierung und energieoekonomische Erweiterung von Typenschulen FKZ 0329224 C

    Energy Technology Data Exchange (ETDEWEB)

    Jahn, S. [Landeshaupstadt Dresden (Germany). Schulverwaltungsamt; Petzold, K.; Roloff, J.; Meinhold, U.; Renner, E.; Eckarth, P. [Technische Univ. Dresden (Germany). Inst. fuer Bauklimatik; Schreck, H.; Hillmann, G.; Jakobiak, R.A. [Institut fuer Bau-, Umwelt- und Solarforschung GmbH, Berlin (Germany); Erhorn, H.; Reiss, J. [Fraunhofer-Institut fuer Bauphysik, Stuttgart (Germany)

    1997-12-31

    The project aims at modernizing school buildings with atria in terms of their thermal energy consumption and, simultaneously, at the optimization of daylighting. The basic idea was to cover the atria with glass roofs to make a building more compact, so that the reduced thermal energy transmission area would drastically cut down specific thermal energy demand without imparing daylighting. The energetic and thermal characteristics of the building are analysed and experience gathered after its modernization, also regarding daylighting, is discussed. (MSK) [Deutsch] Ausser einer heiz-energetischen Sanierung von Schulgebaeuden in Atriumbauweise ist auch eine Optimierung der Tageslichtnutzung beabsichtigt. Der Grundgedanke war, die Innenhoefe mit Glas zu ueberdachen, um eine kompaktere Gebaeudeform zu bekommen und den spezifischen Heizenergiebedarf durch die sich daraus ergebende Verkleinerung der Transmissionsflaeche drastisch zu reduzieren, und dies ohne die Tageslichtbeleuchtung zu beeintraechtigen. Neben der energetischen und thermischen Untersuchung des Gebaeudes werden die Erfahrungen mit dem Schulgebaeude nach dem Umbau sowie die Beleuchtung mit Tageslicht erlaeutert.

  20. The cost efficiency of improved roof windows in two well-lit nearly zero-energy houses in Copenhagen

    DEFF Research Database (Denmark)

    Skarning, Gunnlaug Cecilie Jensen; Hviid, Christian Anker; Svendsen, Svend

    2017-01-01

    .The aim of this study was to quantify the scope for investing in improved roof window solutions inbuildings insulated to consume nearly zero-energy. Based on two single-family houses in Copenhagenwith typical roof windows and adequate daylighting, the study identified the prices at which various typesof......Roof windows are efficient and flexible daylight sources that are essential in certain types of houses if theyare to achieve sufficient daylighting throughout. Previous studies have indicated that, for such buildingsto meet nearly zero-energy targets in an easy and robust way without compromising...... roof window improvements would have to be made available to achieve the same cost efficiency asimproved insulation. If the improvements can be made available for less than these prices, the installationof improved roof windows would make it cheaper to construct well-lit and comfortable nearly zero...

  1. SIMULASI PENCAHAYAAN ALAMI PADA GEDUNG PROGRAM STUDI ARSITEKTUR UNIVERSITAS MALIKUSSALEH

    Directory of Open Access Journals (Sweden)

    Atthaillah Athaillah

    2017-07-01

    Full Text Available ABSTRAK Penelitian ini melakukan investigasi performa pencahayaan alami pada Gedung Program Studi Arsitektur Fakultas Teknik (PAFT Universitas malikussaleh. Berdasarkan observasi pada gedung PAFT, ruangan-ruangan pada bangunan cenderung gelap dan memakai bantuan pencahayaan buatan walaupun pada siang hari, serta memiliki lahan sempit sehingga cahaya alaminya terhalang oleh bangunan perimeter. Tujuan dari penelitian ini adalah untuk menganalisa performa pencahayaan alami khususnya faktor pencahayaan alami (daylight factor pada gedung PAFT dan memberikan solusi desain untuk meningkatkan performa pencahayaan alaminya. Metode penelitian dilakukan melalui simulasi Komputer (computer simulation dengan software Velux Daylight Visualizer versi 2.0 untuk perhitungan faktor pencahayaan alami. Hasil menunjukkan bahwa permasalahan disebabkan oleh beberapa faktor diantaranya adalah kedalaman ruang, posisi ruang, pemilihan material bukaan, penempatan bukaan yang tidak sesuai, kondisi sekitar bangunan (penghalang bangunan, dan Window Wall Ratio (WWR yang kurang memadai. Selanjutnya, penelitian ini memberikan solusi seperti meningkatkan WWR (menambah dan memperluas bukaan, mengganti warna interiordengan warna yang lebih cerah seperti warna putih, mengganti material bukaan dengan nilai Tvis lebih tinggi (0,850 dan menambahkan shading devices pada tempat-tempat yang dianggap Membutuhkan untuk menghindari efek silau berlebihan dalam ruangan. Kata kunci: Pencahayaan Alami, Faktor Pencahayaan Alami, Velux Daylight Visualiser 2.0, Simulasi Komputer   ABSTRACT Daylighting provided significant benefits such as visual comfort and energy saving for a building. In addition, it improved productivity and welbeing of its occupants. As an educational building for architecture, the building of Prodi Arsitektur Fakultas Teknik (PAFT Universitas Malikussaleh, needed to pay attention to its daylighting performance. As observed, on the one hand, spaces within the

  2. Daily activity of the European Badger (Meles meles, Mustelidae, Carnivora on setts in Darwin Reserve and Meschera National Park (Russia in summer and autumn

    Directory of Open Access Journals (Sweden)

    Natalia V. Sidorchuk

    2018-06-01

    Full Text Available The European badger's (Meles meles daily activity was studied in two regions of European Russia with camera traps. The results of the study show that the daily activity of the European badger on settlements does not differ in the compared populations inhabiting Darwin Reserve and Meschera National Park. The badger appears on surface often during the daylight contrary to the classical idea of nocturnal activity of the species. More than half of all animal registrations occur at daylight during the summer. The moderate climate of the study areas and low level of human persecution are considered among the possible reasons of this type of activity. The daily activity of the European badger undergoes markedly seasonal changes in both populations. Badgers more often came out from their setts during daylight in summer and at night in autumn. The results have practical application in the organisation of the census of badgers by means of camera traps.

  3. New design-tools for energy efficient commercial buildings. Neue Planungsinstrumente fuer energiegerechte Verwaltungsgebaeude

    Energy Technology Data Exchange (ETDEWEB)

    Erhorn, H [Fraunhofer-Inst. fuer Bauphysik, Stuttgart (Germany); Szerman, M [Fraunhofer-Inst. fuer Bauphysik, Stuttgart (Germany)

    1993-03-01

    Aim of SHC-Task 12 is to develop and hand out design tools to designers, architects and engineers for the integrated evaluation of daylighting and heating/cooling concepts on an early stage of the actual design process. Concerning the software for the lighting and daylighting evaluation, the following international validated programmes are used: SUPERLITE (Radiosity); RADIANCE (Raytracing); SUPERLINK (linkage between daylighting an energy analysis). The thermal and energetic behaviour of buildings can be analysed with the simulation tools: - SUNCODE; - TRNSYS; - tsbi. The input of the programmes is handled by a common CAD programme and special converters. The software package is produced in international collaboration and will be distributed in 1993. (orig./BWI)

  4. Home, Smart Home

    DEFF Research Database (Denmark)

    Hansen, Ellen Kathrine; Olesen, Gitte Gylling Hammershøj; Mullins, Michael

    2013-01-01

    The article places focus on how smart technologies integrated in a one family- home and particular the window offer unique challenges and opportunities for designing buildings with the best possible environments for people and nature. Toward an interdisciplinary approach, we address the interaction...... between daylight defined in technical terms and daylight defined in aesthetic, architectural terms. Through field-tests of a Danish carbon-neutral home and an analysis of five key design parameters, we explore the contradictions and potentials in smart buildings, using the smart window as example of how...... to the energy design is central. The study illuminates an approach of the design of smart houses as living organisms by connecting technology with the needs of the occupants with the power and beauty of daylight....

  5. Light protection of the skin after photodynamic therapy reduces inflammation

    DEFF Research Database (Denmark)

    Petersen, B; Wiegell, S R; Wulf, H C

    2014-01-01

    whether protection with inorganic sunscreen, foundation or light-blocking plaster after PDT can reduce inflammation caused by daylight-activated PpIX. METHODS: On the right arm of 15 subjects with sun-damaged skin, four identical squares (3 × 3 cm) were given conventional PDT treatment. Immediately after...... red-light illumination the squares were either left unprotected or protected by inorganic sunscreen [sun protection factor (SPF) 50], foundation (SPF50) or light-blocking plaster. The skin was then illuminated with artificial daylight for 2 h and afterwards covered for 24 h. Fluorescence and erythema...... treatment was reduced by 19% with the sunscreen (P = 0·29), by 27% with the foundation (P = 0·10) and by 44% with the silver plaster (P = 0·002). CONCLUSIONS: Artificial daylight exposure after conventional PDT increases skin erythema. Light-blocking plaster gives more effective protection against post...

  6. ADAPTIVE FULL-SPECTRUM SOLAR ENERGY SYSTEMS Cross-Cutting R & D on adaptive full-spectrum solar energy systems for more efficient and affordable use of solar energy in buildings and hybrid photobioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Byard D. Wood; David L. Beshears

    2006-02-01

    This RD&D project is a three year team effort to develop a hybrid solar lighting (HSL) system that transports daylight from a paraboloidal dish concentrator to a luminaire via a bundle of polymer fiber optics. The luminaire can be a device to distribute sunlight into a space for the production of algae or it can be a device that is a combination of daylighting and electric lighting for space/task lighting. In this project, the sunlight is collected using a one-meter paraboloidal concentrator dish with two-axis tracking. For the third generation (beta) system, the secondary mirror is an ellipsoidal mirror that directs the visible light into a bundle of 3 mm diameter fibers. The IR spectrum is filtered out to minimize unnecessary heating at the fiber entrance region. This report describes the following investigations: Niche applications for HSL technology, Luminaire design characteristics for linear and point lighting fixtures, and Daylight affects on productivity.

  7. Lighting Energy Saving with Light Pipe in Farm Animal Production

    Directory of Open Access Journals (Sweden)

    Hans von Wachenfelt

    2015-12-01

    Full Text Available The Swedish animal production sector has potential for saving electric lighting of €4-9 million per year using efficient daylight utilisation. To demonstrate this, two light pipe systems, Velux® (house 1 and Solatube® (house 2, are installed in two identical pig houses to determine if the required light intensity, daylight autonomy (DA, and reduced electricity use for illumination can be achieved. In each house, three light sensors continuously measure the indoor daylight relative to an outdoor sensor. If the horizontal illuminance at pig height decreases below 40 lux between 08.00 and 16.00 hours, an automatic control system activates the lights, and electricity use is measured. The daylight factor (DF and DA are determined for each house, based on annual climate data. The mean annual DA of 48% and 55% is achieved for house 1 and house 2, respectively. Light pipes in house 2 have delivered significantly more DA than those in house 1. The most common illuminance range between 0 and 160 lux is recorded in both houses, corresponding to approximately 82% and 83% of daylight time for house 1 and house 2, respectively. Further, the daylighting system for house 2 has produced a uniform DF distribution between 0.05 and 0.59. The results demonstrate that considerable electric energy savings can be achieved in the animal production sector using light pipes. Saving 50% of electric lighting would correspond to 36 GWh or 2520 t CO2 per year for Sweden, but currently the energy savings are not making the investment profitable.

  8. Out of the Lab and into the Bathroom: Evening Short-Term Exposure to Conventional Light Suppresses Melatonin and Increases Alertness Perception

    Directory of Open Access Journals (Sweden)

    Heinz Schoepp

    2013-01-01

    Full Text Available Life in 24-h society relies on the use of artificial light at night that might disrupt synchronization of the endogenous circadian timing system to the solar day. This could have a negative impact on sleep–wake patterns and psychiatric symptoms. The aim of the study was to investigate the influence of evening light emitted by domestic and work place lamps in a naturalistic setting on melatonin levels and alertness in humans. Healthy subjects (6 male, 3 female, 22–33 years were exposed to constant dim light (<10 lx for six evenings from 7:00 p.m. to midnight. On evenings 2 through 6, 1 h before habitual bedtime, they were also exposed to light emitted by 5 different conventional lamps for 30 min. Exposure to yellow light did not alter the increase of melatonin in saliva compared to dim light baseline during (38 ± 27 pg/mL vs. 39 ± 23 pg/mL and after light exposure (39 ± 22 pg/mL vs. 44 ± 26 pg/mL. In contrast, lighting conditions including blue components reduced melatonin increase significantly both during (office daylight white: 25 ± 16 pg/mL, bathroom daylight white: 24 ± 10 pg/mL, Planon warm white: 26 ± 14 pg/mL, hall daylight white: 22 ± 14 pg/mL and after light exposure (office daylight white: 25 ± 15 pg/mL, bathroom daylight white: 23 ± 9 pg/mL, Planon warm white: 24 ± 13 pg/mL, hall daylight white: 22 ± 26 pg/mL. Subjective alertness was significantly increased after exposure to three of the lighting conditions which included blue spectral components in their spectra. Evening exposure to conventional lamps in an everyday setting influences melatonin excretion and alertness perception within 30 min.

  9. Fabrication of thin-film thermoelectric generators with ball lenses for conversion of near-infrared solar light

    OpenAIRE

    Ito, Yoshitaka; Mizoshiri, Mizue; Mikami, Masashi; Kondo, Tasuku; Sakurai, Junpei; Hata, Seiichi

    2017-01-01

    We designed and fabricated thin-film thermoelectric generators (TEGs) with ball lenses, which separated visible light and near-infrared (NIR) solar light using a chromatic aberration. The transmitted visible light was used as daylight and the NIR light was used for thermoelectric generation. Solar light was estimated to be separated into the visible light and NIR light by a ray tracing method. 92.7% of the visible light was used as daylight and 9.9% of the NIR light was used for thermoelectri...

  10. Integrated Energy Design in Master Planning

    DEFF Research Database (Denmark)

    Strømann-Andersen, Jakob Bjørn

    This PhD thesis considers urban structure and buildings in an energy correlation and use the knowledge to design energy- and comfort-optimized cities and buildings. The parameters are: the structure of nature, the city and the landscape, both in terms of geometry and interrelationships and in terms...... in character as daylight is taken into account. Furthermore the results suggest that there are limits to urban densification (200-300%) as an energy optimization strategy. The solar energy and daylight potential should be considered, and indeed protected, as a common resource in urban design. The most...

  11. Long term stability of cannabis resin and cannabis extracts

    DEFF Research Database (Denmark)

    Lindholst, Christian

    2010-01-01

    at room temperature, 4 °C and - 20 °C for up to 4 years. Acidic THC degrades exponentially via decarboxylation with concentration halve-lives of approximately 330 and 462 days in daylight and darkness, respectively. The degradation of neutral THC seems to occur somewhat slower. When cannabinoids were...... stored in extracted form at room temperature the degradation rate of acidic THC increased significantly relative to resin material with concentration halve-lives of 35 and 91 days in daylight and darkness, respectively. Once cannabis material is extracted into organic solvents, care should be taken...

  12. Seasonal variations in general activity, behaviour and cutaneous glandular structures in reindeer (Rangifer tarandus L.)

    OpenAIRE

    Mossing, Torgny

    1980-01-01

    The locomotor activity of the reindeer is separated into a diurnal and a nocturnal phase which, in turn, consists of a  number of short-term activity bursts. The onset and termination  of diurnal and nocturnal activity are largely in synchrony  with sunrise and sunset. Since the diurnal phase is  longer, total activity is dependent on the photoperiod. Total  activity as well as the number of activity bursts is greater  in Jùne with continuous daylight than in December with 6  hours daylight. ...

  13. "Light and the aesthetics of the perception"

    DEFF Research Database (Denmark)

    Volf, Carlo

    2010-01-01

    through the meeting with form. Therefore, since form has been the major theme for the aesthetics up until now, giving form to light is a complex and challenging task and reducing it to Lux and measurable numbers only an escape from facing what is actually percieved. In this way light seems to suffer from...... this article tries to establish a dialogue between the daylight and the artificial lighting. The article describes how light - this intangible building block – can become a more workable size in the aesthetic and architectural practice of today. KEYWORDS Light, daylight, artificial light, aesthetics...

  14. Ambient air conditions and variation in urban trail use.

    Science.gov (United States)

    Holmes, Ann M; Lindsey, Greg; Qiu, Chenchen

    2009-11-01

    This study examines the effect of air quality and administrative policies on use of urban trails in Indianapolis, IN. Attention is focused on two policy variables: (1) issuance of air pollution advisories and (2) the adoption of Daylight Savings Time. Results suggest that while trail use varies with air quality, current public advisories regarding air pollution may be of limited effectiveness in reducing trail users' exposures to hazardous pollutants. In contrast, the adoption of Daylight Savings Time was associated with a statistically significant increase in traffic levels.

  15. Depressed Patients Hospitalized in Southeast-Facing Rooms Are Discharged Earlier than Patients in Northwest-Facing Rooms

    DEFF Research Database (Denmark)

    Gbyl, Krzysztof; Madsen, Helle Ostergaard; Svendsen, Signe Dunker

    2017-01-01

    in a specialized affective disorders unit investigated the impact of daylight on the length of hospital stay and improvement of depression. Methods: For a period of 1 year, we collected data on sociodemographics, length of stay, vitamin D, and depression severity for patients in an inpatient affective disorders....... Conclusion: Due to the study design, no causality for the observed difference in length of stay can be given, but the results support findings in previous studies of the importance of architectural orientation providing natural daylight as a factor for improvement....

  16. Illuminance Level in the Urban Fabric and in the Room

    DEFF Research Database (Denmark)

    Iversen, Anne; Nielsen, Toke Rammer; Svendsen, Svend

    2011-01-01

    The decisions made on the urban planning level could influence the building design at later stages. Many studies have shown that the utilisation of daylight in buildings would result in significant savings in electricity consumption for lighting, while creating a higher quality indoor environment...... of the exterior illuminance levels on fac¸ades with the interior illuminance levels on the working plane. The paper also explains an easy to use tool (EvUrbanplan) developed by the authors, which was applied to their findings in the early stages of urban planning to ensure daylight optimisation in the buildings....

  17. Acceleration of Radiance for Lighting Simulation by Using Parallel Computing with OpenCL

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Wangda; McNeil, Andrew; Wetter, Michael; Lee, Eleanor

    2011-09-06

    We report on the acceleration of annual daylighting simulations for fenestration systems in the Radiance ray-tracing program. The algorithm was optimized to reduce both the redundant data input/output operations and the floating-point operations. To further accelerate the simulation speed, the calculation for matrix multiplications was implemented using parallel computing on a graphics processing unit. We used OpenCL, which is a cross-platform parallel programming language. Numerical experiments show that the combination of the above measures can speed up the annual daylighting simulations 101.7 times or 28.6 times when the sky vector has 146 or 2306 elements, respectively.

  18. Fibre illumination system

    DEFF Research Database (Denmark)

    2012-01-01

    Source: EP2426402A The invention relates to a fibre illumination module and system for the collection and delivery of daylight for illumination purposes. The fibre illumination module comprises a plurality of collector elements, each collector element comprising an input fibre having a first end......-directional arrangement. The fibre illumination system comprises a fibre illumination module of the above-mentioned type. By the invention, daylight may be exploited for the illumination of remote interior spaces of buildings in order to save energy, and improve the well-being of users in both housing and working...

  19. Severe head injury in children - a preventable but forgotten epidemic

    African Journals Online (AJOL)

    Severe head injury in a child is a sociological disaster that crosses all sociological ... permanently disabled each year as a result of accidental injury." Over a ..... the daylight when transportation of the patient is more rapid; this results in some ...

  20. 76 FR 71322 - Interagency Ocean Observation Committee, Meeting of the Data Management and Communications...

    Science.gov (United States)

    2011-11-17

    ... representing academic, non-profit, private, regional and state sectors who will discuss issues outlined in the..., 2012 between 9 a.m. and 5 p.m., Eastern Daylight Time. ADDRESSES: The meeting will be broadcast via a... about this notice, please contact the U.S. IOOS Program (Charles Alexander, (301) 427-2429, Charles...

  1. Multi-objective and multidisciplinary design optimization of large sports building envelopes : A case study

    NARCIS (Netherlands)

    Yang, D.; Sun, Y.; Turrin, M.; von Buelow, P.; Paul, J.C.

    2015-01-01

    Currently, in the conceptual envelope design of sports facilities, multiple engineering performance feedbacks (e.g. daylight, energy and structural performance) are expected to assist architectural design decision-making. In general, it is known as Building Performance Optimization in the conceptual

  2. Daytime running lights : the attention light : a literature survey of daytime running lights for motor vehicles and their effect on road safety in The Netherlands.

    NARCIS (Netherlands)

    Polak, P.H.

    1987-01-01

    In the history of (motorised) traffic, the role of lighting has assumed increasing importance, not only at night but also during daylight hours. Studies in the U.S. and Sweden demonstrated the positive effect of daytime running lights (DRL) on traffic safety. The aim of this study is to investigate

  3. Helicopter emergency medical service patient transport safe at night?

    NARCIS (Netherlands)

    Peters, J.H.; Wageningen, B. van; Hoogerwerf, N.; Biert, J.

    2014-01-01

    OBJECTIVE: Dutch helicopter emergency medical services are available 24/7. Working without daylight brings additional challenges, both in patient care and in-flight operation. We retrospectively evaluated the safety of this nighttime helicopter transportation of patients. METHODS: Our helicopter

  4. 33 CFR 165.1195 - Regulated Navigation Area; Humboldt Bay Bar Channel and Humboldt Bay Entrance Channel, Humboldt...

    Science.gov (United States)

    2010-07-01

    ... Entrance Channel, Humboldt Bay, California. (b) Definitions. As used in this section— COTP means the... person in charge of a vessel to which this notice applies shall obtain permission to cross within four... place during daylight hours, the vessel has only a single tow or no tow, the visibility at the bar is...

  5. notes on the bathypelagic fauna of the seas around south africa

    African Journals Online (AJOL)

    dwell during daylight hours in the darkness of the mid-depths of the ocean, .... there has long been much active scientific collecting and a large deep-sea ... first author is responsible for the work on invertebrates and hydrography, and ...... Mechanical analysis on the working behaviour of mid water trawl. Bull. Japan. Soc. sci.

  6. Driver electronic device use in 2008

    Science.gov (United States)

    2009-09-01

    The 2008 hand-held cell phone use rate translates into 812,000 vehicles being driven by someone using a hand-held cell phone at any given daylight moment.1 It also translates into an estimated 11 percent of the vehicles whose drivers were using some ...

  7. A Simple Modeling Tool and Exercises for Incoming Solar Radiation Demonstrations

    Science.gov (United States)

    Werts, Scott; Hinnov, Linda

    2011-01-01

    We present a MATLAB script INSOLATE.m that calculates insolation at the top of the atmosphere and the total amount of daylight during the year (and other quantities) with respect to geographic latitude and Earth's obliquity (axial tilt). The script output displays insolation values for an entire year on a three-dimensional graph. This tool…

  8. First approach to the trophic ecology and diet of the rainbow runner, Elagatis bipinnulata (Quoy and Gaimard, 1825) (Pisces: Carangidae), in the central Colombian Caribbean

    International Nuclear Information System (INIS)

    Garcia Ramirez, Camilo Bernardo; Posada, Camila

    2014-01-01

    The rainbow runner (Elagatis bipinnulata) scores high in trophic level (4.24) but it is not a voracious fish (Q/B = 10.8). its diet is dominated by the dwarf herring (Jenkinsia lamprotaenia), eats more in the dry season, than in the rainy season and significantly more in the afternoon that in the morning suggesting preference for daylight feeding.

  9. NOTES ON THE ECOLOGY, CAPTURE AND BEHAVIOUR IN ...

    African Journals Online (AJOL)

    The lighting in the animal room corresponded to the hours of daylight. New captives, however, appeared to respond favourably to an additional light placed immediately over their cage in the middle ofthe day. The captive elephant shrews receive a diet oflocusts, grasshoppers, mealworms, occasional oranges and bananas.

  10. 76 FR 485 - Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model...

    Science.gov (United States)

    2011-01-05

    ... comments received, and other information. The street address for the Docket Office (telephone 800-647-5527... history of airplanes subject to those regulations, and existing maintenance practices for fuel tank... is made under normally available lighting conditions such as daylight, hangar lighting, flashlight...

  11. Efficient lighting in buildings: The lack of legislation in Portugal

    International Nuclear Information System (INIS)

    Almeida, António Manuel; Martins, António Gomes

    2014-01-01

    The behavior of building designers is conditioned by the existing legislation and regulations in the national context in which they operate. However, in the Portuguese legislation there are no rules concerning the use of daylight, and therefore, designers are not stimulated to adopt solutions that make use of the existing potential of sunlight availability. In the same way, it is difficult to understand the lack of specific regulation, with quantified targets, limiting power density of artificial lighting installed inside buildings. The present opportunity, generated by the need to carry out the revision of Portuguese building energy systems regulation, should be used to fill the existing gap in national legislation regarding those matters. In this paper the authors present some proposals for future legislation that will have as central purpose the utilization of efficient lighting systems and the promotion of architectural solutions that optimize the use of daylighting. It is possible, and desirable, to add new directives to national legislation that contribute to the improvement of Portuguese buildings, characterized by its good performance in terms of daylight availability, and at the same time, increasing the energy efficiency and reducing the energy consumption of lighting systems installed in those buildings. - Highlights: • In the Portuguese legislation there are no rules concerning the use of daylight. • Lack of specific regulation limiting power density of artificial lighting. • Revision of Portuguese building energy systems regulation. • Some proposals for future legislation. • Improvement of Portuguese buildings promoting energy efficiency

  12. 78 FR 66989 - Designation of Six Individuals and Four Entities Pursuant to Executive Order 13581, “Blocking...

    Science.gov (United States)

    2013-11-07

    ...). The Order was effective at 12:01 a.m. eastern daylight time on July 25, 2011. In the Order, the.... ``GRISHA''), Phuket, Thailand; DOB 16 Jul 1962; POB Sochi, Russia (individual) [TCO]. 3. LYALIN, Vadim... Marine Tower, P.O. Box 1102, Dubai, United Arab Emirates; DOB 30 Sep 1973; Passport 4510935440 (Russia...

  13. Performance-Oriented Design of Large Passive Solar Roofs : A method for the integration of parametric modelling and genetic algorithms

    NARCIS (Netherlands)

    Turrin, M.; Von Buelow, P.; Stouffs, R.M.F.; Kilian, A.

    2010-01-01

    The paper addresses the design of large roof structures for semi outdoor spaces through an investigation of a type of performance-oriented design, which aims at integrating performance evaluations in the early stages of the design process. Particularly, aiming at improving daylight and thermal

  14. Financial Crisis and Social Change in South East Asia

    DEFF Research Database (Denmark)

    Schmidt, Johannes Dragsbæk

    1) Crisis - Dangers and Opportunities 2) "Creative destruction" or Robbery in Open Daylight! 3) Strings and Conditionalities of the IFIs 4) De-regulating Labor Markets/Targetting the Poor And Avoiding Social Chaos 5) Introducing Flexibility in Labor Markets/Impacts 6) Growing inequalities...... - Distributional consequences 7) Informalization of Labor Markets 8) Increased Social and Political Instability 9) Concluding Remarks...

  15. Portable real-time color night vision

    NARCIS (Netherlands)

    Toet, A.; Hogervorst, M.A.

    2008-01-01

    We developed a simple and fast lookup-table based method to derive and apply natural daylight colors to multi-band night-time images. The method deploys an optimal color transformation derived from a set of samples taken from a daytime color reference image. The colors in the resulting colorized

  16. Light therapy: Methodological issues from an engineering perspective

    NARCIS (Netherlands)

    MD E.J.M. Wouters; AC Westerlaken; MBC Aries; AMC Schoutens; MM Sinoo; Joost van Hoof; MPJ Aarts

    2012-01-01

    Light therapy is increasingly administered and studied as a non-pharmacologic treatment for a variety of health-related problems, including treatment of people with dementia. Light therapy comes in a variety of ways, ranging from being exposed to daylight, to being exposed to light emitted by light

  17. Light therapy: Methodological issues from an engineering perspective

    NARCIS (Netherlands)

    A.C. Westerlaken; A.M.C. Schoutens; M.P.J. Aarts; M.B.C. Aries; M.M. Sinoo; J. van Hoof; E.J.M. Wouters

    2012-01-01

    Light therapy is increasingly administered and studied as a non-pharmacologic treatment for a variety of healthrelated problems, including treatment of people with dementia. Light therapy comes in a variety of ways, ranging from being exposed to daylight, to being exposed to light emitted by light

  18. Light therapy: Methodological issues from an engineering perspective.

    NARCIS (Netherlands)

    Joost van Hoof; Aries; MD E.J.M. Wouters; Van Someren; Schoutens; Westerlaken; Aarts; Sinoo

    2011-01-01

    Light therapy is increasingly administered and studied as a non-pharmacologic treatment for a variety of health-related problems. Light therapy comes in a variety of ways, ranging from being exposed to daylight to being exposed to light from light boxes and ambient bright light. Light therapy is an

  19. Light therapy : methodological issues from an engineering perspective

    NARCIS (Netherlands)

    Hoof, van J.; Westerlaken, A.C.; Aarts, M.P.J.; Wouters, E.J.M.; Schoutens, A.M.C.; Sinoo, M.M.; Aries, M.B.C.

    2012-01-01

    Light therapy is increasingly administered and studied as a non-pharmacologic treatment for a variety of healthrelated problems, including treatment of people with dementia. Light therapy comes in a variety of ways, ranging from being exposed to daylight, to being exposed to light emitted by light

  20. Reappearance of the tapetal-like reflex after prolonged dark adaptation in a female carrier of RPGR ORF15 X-linked retinitis pigmentosa

    DEFF Research Database (Denmark)

    Bregnhøj, Jesper; Al-Hamdani, Sermed; Sander, Birgit

    2014-01-01

    PURPOSE: To report changes in the tapetal-like reflex in a female carrier of RPGR ORF15 c.3395delA X-linked retinitis pigmentosa (XLRP) between examinations at 16 and 22 years of age, and to report the observation that the tapetal-like reflex faded due to exposure to daylight and reappeared...

  1. Diel vertical migration arising in a habitat selection game

    DEFF Research Database (Denmark)

    Sainmont, Julie; Thygesen, Uffe Høgsbro; Visser, Andre

    2013-01-01

    , avoiding their predator during their peak performance by finding refuge in deep layers during daylight hours and feeding at the surface during the night. Due to the duality of the interaction between prey and predator, we used a game theory approach to investigate whether DVM can be a suitable strategy...

  2. 50 CFR 218.5 - Requirements for monitoring and reporting.

    Science.gov (United States)

    2010-10-01

    ... array shall be deployed during daylight hours for each of the days the ship is at sea. (ii) The towed... method for standardizing data collection for VACAPES Range Complex and across range complexes. (e... Monitoring Plan. Data collection methods shall be standardized across range complexes to allow for comparison...

  3. 50 CFR 218.14 - Requirements for monitoring and reporting.

    Science.gov (United States)

    2010-10-01

    ... array shall be deployed during daylight hours for each of the days the ship is at sea. (ii) The towed... method for standardizing data collection for JAX Range Complex and across range complexes. (e) General... collection methods will be standardized across range complexes to allow for comparison in different...

  4. 76 FR 60455 - The White House Council for Community Solutions Gives Notice of Their Following Meeting

    Science.gov (United States)

    2011-09-29

    ... CORPORATION FOR NATIONAL AND COMMUNITY SERVICE Sunshine Act Meeting Notice The White House Council for Community Solutions Gives Notice of Their Following Meeting DATE AND TIME: Friday, October 14, 2011, 9 a.m.-12:30 p.m. Eastern Daylight Time. PLACE: The Council will meet in the Eisenhower Executive...

  5. Atmospheric Trajectory and Orbit of the Osceola Meteorite (January 24, 2016)

    Science.gov (United States)

    Gritsevich, M.; Lyytinen, E.; Hankey, M.; Meier, M. M. M.; Matson, R.; Fries, M.

    2017-07-01

    We present a summary on the trajectory reconstruction, dark flight simulations and the pre-impact orbit estimate for the day-light fireball widely observed over northern Florida (USA), on January 24, 2016 at 10:27 EST (15:27 UTC).

  6. Atmospheric trajectory and orbit of the Osceola meteorite

    Science.gov (United States)

    Gritsevich, M.; Lyytinen, E.; Hankey, M.; Meier, M. M. M.; Matson, R.; Fries, M.

    2017-09-01

    We present a summary on the trajectory reconstruction, dark flight simulations and the pre-impact orbit estimate for the day-light Osceola fireball widely observed over northern Florida (USA) on January 24, 2016 at 10:27 EST (15:27 UTC).

  7. Daily metabolized energy consumption of Oystercatchers Haematopus ostralegus feeding on larvae of the crane fly Tipula paludosa

    NARCIS (Netherlands)

    Zwarts, L; Blomert, AM

    1996-01-01

    Oystercatchers feeding on grassland in spring mainly take leatherjackets, the larvae of the crane fly Tipula paludosa. The birds roost at night and feed for 40 to 60% of the daylight period. Their intake rate during feeding is 1 to 1.5 mg AFDW or 20 to 30 J s(-1), which is rather low compared to the

  8. TCM in lighting design : an integrative medical methodology in light research

    NARCIS (Netherlands)

    Pan, Y.; Zielinska-Dabkowska, Karolina M.; Rohde, Michael F.

    2017-01-01

    The advancement of artificial lighting technology has enabled a lifestyle free from the restriction of natural daylight. However, scientists have discovered that light, assisting the cardiovascular system and synchronizing the biological clock, is a vital form of energy and information to sustain

  9. Pest Prevention 101 | Poster

    Science.gov (United States)

    During the summer months, along with rising temperatures and more daylight, comes the nuisance of mosquitoes, ticks, and other insects. In the United States, mosquito bites are largely no more than an annoyance, but worldwide, mosquitoes transmit disease to more than 700 million people every year, according to the Annals of Internal Medicine. And the recent outbreaks of the

  10. 33 CFR 117.697 - Hampton River.

    Science.gov (United States)

    2010-07-01

    ... each high tide. “Daylight hours” means one-half hour before sunrise to one-half hour after sunset. High tide occurs one-half hour later than the time of high tide for Portland, Maine, as published in the tide tables published by private entities using data provided by the National Ocean Service. At all...

  11. International piracy and armed robbery at sea : hindering maritime trade and water transportation around the world

    Science.gov (United States)

    2010-04-01

    Pirates prey upon targets of opportunity. Given optimal conditions (e.g., calm weather, slow cruising speed, and daylight4) relatively small, fast vessels (e.g., containerships) may be no less at risk than large, slower vessels (e.g., crude carriers)...

  12. 10 CFR 434.201 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... instrumentation for the supplementary monitoring of energy consumption (electric, gas, oil, etc) to isolate the... sunlight. Daylighted space: the space bounded by vertical planes rising from the boundaries of the..., based upon temperature difference and time, used in estimating cooling energy consumption. For any one...

  13. 77 FR 26476 - Standards of Performance for Greenhouse Gas Emissions for New Stationary Sources: Electric...

    Science.gov (United States)

    2012-05-04

    ... conclude the hearing at 4:30 p.m. All Chicago times are Central Daylight Time (CDT). The EPA's Web site for... require the service of a translator, please let us know at the time of registration. Questions concerning..., including lists of speakers, will be posted on the EPA's Web site at http://www.epa.gov...

  14. Solar Glazing Tips for School Construction

    Science.gov (United States)

    Smith, Jonathan

    2012-01-01

    Glazing can be optimized to enhance passive solar heating and daylight harvesting by exceeding the prescriptive limits of the energy code. This savings can be garnered without the high cost of external overhangs or expensive glazing products. The majority of savings from solar glazing are attributable to the increase in solar heating and…

  15. Solar Process Heat Basics | NREL

    Science.gov (United States)

    Process Heat Basics Solar Process Heat Basics Commercial and industrial buildings may use the same solar technologies-photovoltaics, passive heating, daylighting, and water heating-that are used for residential buildings. These nonresidential buildings can also use solar energy technologies that would be

  16. Germination and Seedling Development of Seeds from Different Parkia biglobosa (Jacq G. Don Trees

    Directory of Open Access Journals (Sweden)

    Christiana O. ADEYEMI

    2013-02-01

    Full Text Available The effect of daylight, continuous illumination and acid scarification on the seed germination and seedling vegetative growth (epicotyl and hypocotyl lengths, and number of secondary roots of different Parkia biglobosawere investigated in the Plant Physiology Laboratory University of Ilorin, Ilorin Kwara State Nigeria. Seeds from two out of the twenty six Parkia tree samples (trees B and T germinated within 24 hours of planting in the daylight germination study while seeds from another tree (Q did not germinate until the third week after planting (3WAP. Some seeds have higher germination percentage both in the daylight (preliminary germination study and in the continuous light (illuminated study. The treatment with concentrated Sulphric acid (conc. H2SO4was effective in breaking the seed dormancy as seeds from eight (8 trees produced one hundred percent (100% germination. At p= 0.05 the length of epicotyl and hypocoty1 lengths were significantly different as seedling vegetative growth were long in the seedlings from the daylight experiment than the continuous light experiment. The vegetative growths of the seedlings from the scarified seed were longer at 15min of scarification in all except in trees F and Z. It was observed that the time of scarification affect the both seed germination and seedling development.

  17. Day-light-controlled artificial lighting a potential energy saver": right interior light by sky luninance trracking

    NARCIS (Netherlands)

    Rutten, A.J.F.; Mills, Evan

    1991-01-01

    The energy consumption in office buildings can considerably be cut, if daylight is used as task lighting. A conservative estimate - starting from existing knowledge and calculation methods - gives a potential saving of 460 GWh a year or 46 % of the electricity costs for artificial lighting in Dutch

  18. Sky luminance research imperative for adequate ciontrol of temporary supplementary artificial lighting installations

    NARCIS (Netherlands)

    Rutten, A.J.F.

    1994-01-01

    The energy consumption in Dutch office buildings can be cut considerably if daylight is used as task lighting. A conservative estimate gives a potential saving of 46% on the electricity costs for artificial lighting. The problem of photo-electric control of artificial lighting supplementing the

  19. Joining the Great Plains in Space, Place, and Time: Questioning a Time Zone Boundary

    Science.gov (United States)

    Kuper, Rob

    2011-01-01

    Standard time zone boundaries are invisible in the landscape, yet they abruptly delineate a temporal difference of one hour between two large areas located relative to one another on Earth. In most cases, standard time zone boundaries follow political ones and define areas within which daylight saving time (DST)--the seasonal advancement of…

  20. Modelling flight heights of lesser black-backed gulls and great skuas from GPS: a Bayesian approach

    NARCIS (Netherlands)

    Ross-Smith, V.H.; Thaxter, C.B.; Masden, E.A.; Shamoun-Baranes, J.; Burton, N.H.K.; Wright, L.J.; Rehfisch, M.M.; Johnston, A.

    2016-01-01

    * Wind energy generation is increasing globally, and associated environmental impacts must be considered. The risk of seabirds colliding with offshore wind turbines is influenced by flight height, and flight height data usually come from observers on boats, making estimates in daylight in fine

  1. Parametri i praksis

    DEFF Research Database (Denmark)

    Banke, Tore

    2013-01-01

    of Fine Arts, School of Architecture, Design and Conservation. The project investigates how daylight quality, solar radiation control, and visual and thermal control can be design pa¬rameters in the initial design phase. The research is based on practical experiments performed in the competition...

  2. 75 FR 17166 - NASA Advisory Council; Aeronautics Committee; Meeting

    Science.gov (United States)

    2010-04-05

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (10-038)] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory... a.m. to 1 p.m.; Eastern Daylight Time. ADDRESSES: NASA Langley Research Center, Building 1219, Room...

  3. Rapid turn-around mapping of wildfires and disasters with airborne infrared imagery fro the new FireMapper® 2.0 and Oilmapper systems

    Science.gov (United States)

    James W. Hoffman; Lloyd L. Coulter; Philip J Riggan

    2005-01-01

    The new FireMapper® 2.0 and OilMapper airborne, infrared imaging systems operate in a "snapshot" mode. Both systems feature the real time display of single image frames, in any selected spectral band, on a daylight readable tablet PC. These single frames are displayed to the operator with full temperature calibration in color or grayscale renditions. A rapid...

  4. Experimental study on modelling and control of lighting components in a test-cell building

    NARCIS (Netherlands)

    Yahiaoui, Azzedine

    2018-01-01

    The perfect control of shading devices, particularly venetian blinds can significantly improve the rational use of daylight in buildings and provide enhanced visual comfort for occupants while saving the electricity that would be used for artificial lighting. This study proposes a control strategy

  5. Implementing non-image-forming effects of light in the built environment : A review on what we need

    NARCIS (Netherlands)

    Khademagha, P.; Aries, M.B.C.; Rosemann, A.L.P.; van Loenen, E.J.

    2016-01-01

    This paper presents a theoretical framework for incorporating the non-image-forming effects of light into daylighting design in the built environment. The framework includes human performance indicators to measure the magnitude of the non-image-forming effects of light as well as light factors to

  6. Simulation-Based Multiobjective Optimization of Timber-Glass Residential Buildings in Severe Cold Regions

    Directory of Open Access Journals (Sweden)

    Yunsong Han

    2017-12-01

    Full Text Available In the current context of increasing energy demand, timber-glass buildings will become a necessary trend in sustainable architecture in the future. Especially in severe cold zones of China, energy consumption and the visual comfort of residential buildings have attracted wide attention, and there are always trade-offs between multiple objectives. This paper aims to propose a simulation-based multiobjective optimization method to improve the daylighting, energy efficiency, and economic performance of timber-glass buildings in severe cold regions. Timber-glass building form variables have been selected as the decision variables, including building width, roof height, south and north window-to-wall ratio (WWR, window height, and orientation. A simulation-based multiobjective optimization model has been developed to optimize these performance objectives simultaneously. The results show that Daylighting Autonomy (DA presents negative correlations with Energy Use Intensity (EUI and total cost. Additionally, with an increase in DA, Useful Daylighting Illuminance (UDI demonstrates a tendency of primary increase and then decrease. Using this optimization model, four building performances have been improved from the initial generation to the final generation, which proves that simulation-based multiobjective optimization is a promising approach to improve the daylighting, energy efficiency, and economic performances of timber-glass buildings in severe cold regions.

  7. Solar car park in a spa town; Das Solarparkhaus an der Kurpromenade

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Willi

    2010-11-23

    Bad Lippspringe is the first spa town in the German state of Nordrhein-Westfalen that installed a solar park garage. The roof consists of semistransparent solar modules that ensure daylighting even in the winter season. There are safety nets below the modules to protect cars and persons from injuries in case of glassbreak. (orig.)

  8. NATURAL LIGHTING OF DEEP ARCHITECTURAL SPACE: THE PERCEPTION OF NEW ZEALAND ARCHITECTS

    Directory of Open Access Journals (Sweden)

    Richard Barrett

    2008-07-01

    Full Text Available The paper considers aspects of a survey carried out amongst a group of registered New Zealand architects in order to establish their knowledge and experience in using core-daylighting systems and methods (Barrett, 2003. Core-daylighting comprises systems and methods for bringing natural light into deep architectural space where conventional methods (such as windows and skylights cannot readily be used. Examples of these methods are: atria (Matusiak, 1998, sun tracking heliostats, sun and light pipes, light scoops, Fresnel lenses, anidolic zenithal systems, prismatic daylight systems, light shelves, tapping mirrors, light reflectors and louvres (Littlefair, 1991, 1996 & 2000, lightwells, internal courts (Lam, 1986, fibre optic cable (Kay,1999, and other systems for light re-direction. The survey was carried out using a questionnaire as described below (Survey Methods. The findings were analysed, resulting in a clear indication that the respondents were not especially experienced or knowledgeable, and a majority felt this to be an area of their skill base in need of development. Whilst the survey was strictly intended to gather quantitative material, respondents were invited to comment freely as they progressed through to completion of the questionnaire. This paper draws on this qualitative data as an insight into several areas, including the attitudes of respondents towards their clients when making decisions about designing buildings for natural daylighting.

  9. The diurnal vertical dynamics of cape hake and their potential prey ...

    African Journals Online (AJOL)

    cephalopods. Together with their cohabitant potential prey, hake are known to undertake diurnal vertical migrations, aggregating near the bottom during daylight, but migrating off the bottom at night. An attempt to determine the ... predation dominating. This may indicate a feeding strategy where vision is not important.

  10. National Astronomy Day: Bringing the Universe to Your Students

    Science.gov (United States)

    Fendrich, Jean; Brown, Mark

    2012-01-01

    How do teachers help students realize their place in the universe? How do they teach the relationship among the Earth, Moon, stars, and galaxies during daylight hours? Most teachers assume that astronomy is a difficult subject to teach in the classroom and that without a planetarium little can be learned. In this article, the authors discuss…

  11. A Proposed Astronomy Learning Progression for Remote Telescope Observation

    Science.gov (United States)

    Slater, Timothy F.; Burrows, Andrea C.; French, Debbie A.; Sanchez, Richard A.; Tatge, Coty B.

    2014-01-01

    Providing meaningful telescope observing experiences for students who are deeply urban or distantly rural place-bound--or even daylight time-bound--has consistently presented a formidable challenge for astronomy educators. For nearly 2 decades, the Internet has promised unfettered access for large numbers of students to conduct remote telescope…

  12. Effect of testosterone and growth hormone injection before puberty ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-03

    Sep 3, 2008 ... during the ovulatory cycle, by the inhibition of its specific receptor with ... g/d/hen). Birds were maintained under day-light (about 12 h), and .... profiles in cyclic mares treated during different stages of the estrous cycle. Dom.

  13. Effects of season and regulated photoperiod on the reproductive ...

    African Journals Online (AJOL)

    user

    constant photoperiod (10 h light and 14 h darkness) and control sows (n = 187) ... Keywords: Season, regulated photoperiod, return to oestrus, farrowing rate, litter size .... were exposed to a minimum daylight cycle of 10.4 h during winter and a ...

  14. An artificial solar spectrum substantially alters plant development compared with usual climate room irradiance spectra

    NARCIS (Netherlands)

    Hogewoning, S.W.; Douwstra, P.; Trouwborst, G.; Ieperen, van W.; Harbinson, J.

    2010-01-01

    Plant responses to the light spectrum under which plants are grown affect their developmental characteristics in a complicated manner. Lamps widely used to provide growth irradiance emit spectra which are very different from natural daylight spectra. Whereas specific responses of plants to a

  15. A robust feldspar luminescence dating method for Middle and Late Pleistocene sediments

    DEFF Research Database (Denmark)

    Buylaert, Jan-Pieter; Jain, Mayank; Murray, Andrew S.

    2012-01-01

    observations is discussed, and the method is shown to be accurate back to 600 ka. The post-IR IRSL signal is reduced by exposure to daylight more slowly than that from quartz and low-temperature IRSL, preventing its general application to young (e.g. Holocene) sediments. Nevertheless, this new approach...

  16. 78 FR 21343 - New Ski Area Water Rights Clause

    Science.gov (United States)

    2013-04-10

    ..., 2013; and the offices of the Forest Service's Lake Tahoe Basin Management Unit, 35 College Drive, in... Sports Program Manager, Recreation, Heritage, and Volunteer Resources Staff, at 801- 975-3793... 800-877-8339 between 8:00 a.m. and 8:00 p.m., Eastern Daylight Time, Monday through Friday. Dated...

  17. 78 FR 60816 - Proposed Directive for Additional Seasonal or Year-Round Recreation Activities at Ski Areas

    Science.gov (United States)

    2013-10-02

    ... land management plan. Since SAROEA provides that snow sports must remain paramount at ski areas on NFS... Winter Sports Program Manager, 707-562-8842. Individuals who use telecommunication devices for the deaf...., Eastern Daylight Time, Monday through Friday. SUPPLEMENTARY INFORMATION: 1. Background and Need for the...

  18. 77 FR 31636 - Wildlife and Hunting Heritage Conservation Council

    Science.gov (United States)

    2012-05-29

    .... (Mountain daylight time). For deadlines and directions on registering to attend, submitting written material... conservation community, the shooting and hunting sports industry, wildlife conservation organizations, the... (Service), in consultation with the Director, Bureau of Land Management (BLM); Chief, Forest Service (USFS...

  19. 78 FR 42104 - Wildlife and Hunting Heritage Conservation Council

    Science.gov (United States)

    2013-07-15

    ...: Teleconference: Tuesday, July 30, 2013, 2-3:30 p.m. (Eastern daylight time). For deadlines and directions on... Management (BLM); Director, National Park Service (NPS); Chief, Forest Service (USFS); Chief, Natural... conservation and ethics in hunting and shooting sports recreation; 4. Stimulating sportsmen and women's...

  20. 76 FR 30192 - Wildlife and Hunting Heritage Conservation Council

    Science.gov (United States)

    2011-05-24

    .... and Thursday, June 16, 2011, from 8 a.m. to 4 p.m. (Eastern daylight time). Meeting Participation: The... sporting conservation community, the shooting and hunting sports industry, wildlife conservation... Wildlife Service (Service), in consultation with the Director, Bureau of Land Management (BLM); Chief...