Lighting

This study projects electricity savings, cost-benefit analysis and emission reduction of lighting retrofits in Malaysia residential sector. The cost-benefit is determined as a function of energy savings due to retrofit of more efficient lighting system. The energy savings were calculated based on 25, 50 and 75% of potential retrofits of inefficient lighting in residential sector. The study found that, this strategy save a significant amount of energy and consumers money. However, an effort to create energy efficiency awareness among consumers and subsidies efficient lighting should be identified, because this efficient lighting is quite expensive in Malaysia. © 2004 Elsevier B.V. All rights reserved.

http://ac.els-cdn.com/S0378778804003329/1-s2.0-S0378778804003329-main.pdf?_tid=350c247c-a9c6-11e3-99d9-00000aab0f01&acdnat=1394615631_782b65a7b4a65cc35b795363f0df0acb 
www.sciencedirect.com/science/article/pii/S0378778804003329

Evidence linking home hazards to falls has not been well established. The evidence-based approach to fall-risk assessment in longitudinal studies becomes difficult because of exposures that change during follow-up. We conducted a cohort study to determine the prevalence of hazards and to resolve whether they are linked to the risk of falls among 959 seniors receiving home-care services. A home hazards assessment was completed at entry and every six months thereafter using a standardized form. The adjusted (for a number of confounding factors) relationship between home hazards and falls was estimated using a survival model taking into account updated time-varying exposures and multiple events. Falls leading to a medical consultation were examined as a secondary outcome, hypothesized as a measure of severity. Home environmental hazards were found in 91% of homes, with a mean of 3.3 risks per individual. The bathroom was the most common place for hazards. The presence of hazards was si...

ABSTRACT: Cassava is one of the most important food crops in Africa. Meristem culture is an effective method of eliminating viruses and other systemic diseases spread through the vegetative propagation of stems. However, in semi-arid conditions, survival of ex vitro plants in the field is often disappointing. When an increasing range of light regimes in vitro was provided, the fresh and dry masses more than doubled their values between 29 and 369 mmol s−1 m−2 PPFDs. Increases in numbers of senescent leaves and stem thickness were also recorded with increasing PPFD. However, PPFD above 101 mmol s−1 m−2 resulted in 30–70% reduction in plant survival, with the thin plants with the smallest fresh and dry masses being the ones with highest survival rates. High light and temperature levels in the greenhouse were also found to be critical for plant survival. It was also shown that transpirational loss from detached leaves and epicuticular wax deposits were not good indicators for predicting survival of ex vitro cassava plantlets during acclimatisation.

During the past few years, organic light emitting diodes (OLEDs) have been increasingly studied due to their emerging applicability. However, some of the properties of existing OLEDs could be improved, such as their overall efficiency and durability; these aspects have been addressed in the current study. A series of novel hole-transporting materials (HTMs) 3a-c based on 4-(9H-carbazol-9-yl)triphenylamine conjugated with different carbazole or triphenylamine derivatives have been readily synthesized by Suzuki coupling reactions. The resulting compounds showed good thermal stabilities with high glass transition temperatures between 148 and 165 °C. The introduction of HTMs 3b and 3c into the standard devices ITO/HATCN/NPB/HTMs 3 (indium tin oxide/dipyrazino(2,3-f:2',3'-h)quinoxaline…

Human vision works in a complex way in the mesopic luminance range which is not yet clearly understood, although several important visual tasks are performed at these luminance levels. In this study, spectral data for detection visibility and recognition contrast sensitivity were obtained in visual experiments. From our data it appears that chromatic channels also influence mesopic contrast sensitivity. An achromatic model of spectral sensitivity is fitted to our experimental data and the remaining chromatic components are discussed.

Residential buildings are responsible for a large share of the total energy consumption. It is well-known that the correct use of natural and artificial lighting can improve energy efficiency. However, lighting in residential buildings should meet other requirements: safety, security, health, comfort, well-being and functional performance. This paper presents an analysis of how these requirements have been incorporated in the Portuguese building regulatory system. The analysis focuses on the regulatory framework, certification systems, incentive programs and awareness initiatives. The main conclusion is that the regulatory system lays down provision mainly on functional performance and energy saving. Lighting requirements regarding safety, security, health, comfort and well-being are often neglected or minimized in regulatory documents. Specialized documents and initiatives present a comprehensive approach. Daylighting design is a challenge, due to its complexity, but has potential ...

To investigate how light intensity changes as the distance increases from the tip of the light guide. Ten different curing light/light guide combinations were used. Light intensity was measured at 0, 3, 6, and 10 mm from the tip of the light guide with a radiometer. Measurements were repeated in five separate trials and the mean light intensity +/- standard deviation was calculated. The fiber density was measured at the entrance and exit of all ten light guides and the light dispersion patterns were recorded. Light intensity decreased as distance increased for all lights tested; however, the rate and extent of this decrease was not similar for all lights (p < 0.0001). Turbo light guides exhibited a more rapid decrease in intensity as the distance increased than standard light guides. At 10 mm, all the turbo light guides had lost over 80% of their intensity recorded at 0 mm. 1. The rate and extent of the decrease in intensity is not similar among curing lights (p < 0.0001). 2. ...

On Wednesday, Dec. 21, nations in the Northern Hemisphere will mark the winter solstice – the shortest day and longest night of the year. For thousands of years people have marked this event with rituals and celebrations to signal the rebirth of the sun and its victory over darkness.

At hundreds, and perhaps thousands, of missions stretching from northern California to Peru, the winter solstice sun triggers an extraordinarily rare and fascinating event – something that I discovered by accident and first documented in one California church nearly 20 years ago.  See article at On Wednesday, Dec. 21, nations in the Northern Hemisphere will mark the winter solstice – the shortest day and longest night of the year. For thousands of years people have marked this event with rituals and celebrations to signal the rebirth of the sun and its victory over darkness. See link to online magazine at https://theconversation.com/a-sacred-light-in-the-darkness-winter-solstice-illuminations-at-spanish-missions-70250

وجود پارک ها در خط ساحلی می تواند به جذب مخاطب به این فضاها کمک کند. پارک های شهری و به طور خاص بخشی از فضاهای سبز عمومی هستند که بازدهی اجتماعی دارند و عموم مردم از آنها در گذران اوقات فراغت ،تفریح و مصاحبت با دوستان و گردهمایی اجتماعی و نظایر اینها استفاده می کنند . شب هنگام فضاهای شهری پارک ها به عنوان فضاهای زنده ،متنوع مملو از عبور و مرور مورد استفاده قرار می گیرند، هدف این پژوهش به بررسی نقش نورپردازی بر افزایش حس دعوت کنندگی در یکی از پارک های ساحلی شهر بندرعباس پرداخته است. از این رو روش مصاحبۀ نیمه ساختاری در جهت جمع آوری داده ها برای این پژوهش انتخاب شده ونمونۀ آماری از 33 نفر به صورت حضوری مصاحبه شده است و نتایج مصاحبه با نرم افزار اکسل به صورت جدول دسته بندی شده است. پارک غدیر که داده ها در آن مکان جمع آوری شده است یک پارک ساحلیست که با توجه به پاسخ اکثریت مصاحبه شوندگان ساحل را عامل جذابیت پارک می دانستند و در آن مکان خاطره دارند. با توجه به پاسخ مصاحبه شوندگان مسیرهای پیاده روی در بعضی از نقاط به علت عدم نورپردازی مناسب در شب مورد استفاده قرار نمی گیرد. یکی از دلایل حضور مردم در پارک ها فعالیت هایی است که در آن پارک انجام می شود و حضور مردم باعث سرزندگی فضاها می شود. حضور افراد مختلف و انجام فعالیت های ورزشی و تفریحی متنوع در پارک بعنوان یکی از دلایل حضور مردم در این پارک شناخته شده است. از این رو نورپردازی در پارک ها باید به گونه ای باشد که رهگذران در آرامش باشند و فضا امکان انجام فعالیت های مختلف را برای مردم فراهم کند، شهر در شب با حضور انسان تعریف می شود و نورپردازی مناسب فضاهای شهری می تواند خاطره ساز شده و در حافظه جمعی شهر بنشیند که یافته ها نشان داده خوانایی ، هویت، تنوع ، امنیت ،سرزندگی در افزایش حس دعوت کنندگی درپارک تاثیر دارد. بدین ترتیب نورپردازی و رو شنایی یک شهر در شب می تواند به گونه ای در شناسایی هرچه بیشتر شهر و حضورپذیری افراد کمک کند

Contrary to the implication of the term “lightness constancy”, asymmetric lightness matching has never been found to be perfect unless the scene is highly articulated (i.e., contains a number of different reflectances). Also, lightness constancy has been found to vary for different observers, and an effect of instruction (lightness vs. brightness) has been reported. The elusiveness of lightness constancy presents a great challenge to visual science; we revisit these issues in the following experiment, which involved 44 observers in total. The stimuli consisted of a large sheet of black paper with a rectangular spotlight projected onto the lower half and 40 squares of various shades of grey printed on the upper half. The luminance ratio at the edge of the spotlight was 25, while that of the squares varied from 2 to 16. Three different instructions were given to observers: They were asked to find a square in the upper half that (i) looked as if it was made of the same paper as that on which the spotlight fell (lightness match), (ii) had the same luminance contrast as the spotlight edge (contrast match), or (iii) had the same brightness as the spotlight (brightness match). Observers made 10 matches of each of the three types. Great interindividual variability was found for all three types of matches. In particular, the individual Brunswik ratios were found to vary over a broad range (from .47 to .85). That is, lightness matches were found to be far from veridical. Contrast matches were also found to be inaccurate, being on average, underestimated by a factor of 3.4. Articulation was found to essentially affect not only lightness, but contrast and brightness matches as well. No difference was found between the lightness and luminance contrast matches. While the brightness matches significantly differed from the other matches, the difference was small. Furthermore, the brightness matches were found to be subject to the same interindividual variability and the same effect of articulation. This leads to the conclusion that inexperienced observers are unable to estimate both the brightness and the luminance contrast of the light reflected from real objects lit by real lights. None of our observers perceived illumination edges purely as illumination edges: A partial Gelb effect (“partial illumination discounting”) always took place. The lightness inconstancy in our experiment resulted from this partial illumination discounting. We propose an account of our results based on the two-dimensionality of achromatic colour. We argue that large interindividual variations and the effect of articulation are caused by the large ambiguity of luminance ratios in the stimulus displays used in laboratory conditions.

Despite the considerable injury burden attributable to falls at home among the general population, few effective safety interventions have been identified. We tested the safety benefits of home modifications, including handrails for outside steps and internal stairs, grab rails for bathrooms, outside lighting, edging for outside steps, and slip-resistant surfacing for outside areas such as decks and porches. We did a single-blind, cluster-randomised controlled trial of households from the Taranaki region of New Zealand. To be eligible, participants had to live in an owner-occupied dwelling constructed before 1980 and at least one member of every household had to be in receipt of state benefits or subsidies. We randomly assigned households by electronic coin toss to either immediate home modifications (treatment group) or a 3-year wait before modifications (control group). Household members in the treatment group could not be masked to their assigned status because modifications were...

Reflections on LUZBOA by Kai Becker. Obviously not my text, but certainly one where a few my ideas resonate with the author's experience of the city.

Reflexões sobre a LUZBOA, por Kai Becker. Obviamente, o texto não é meu, mas certamente que nele algumas das minhas ideias entram em ressonância com a experiência de Lisboa vivenciada pelo autor.

Source: Becker, Kai; The dark side of the “White City”, Professional Lighting Design, ELDA+ European Lighting Designer’s Association, N. 52, Nov/Dec. 2006, pp. 14-15.

Resumo O presente trabalho aborda a questão da influência da temperatura de cor da luz artificial LED juntamente com a luz natural e seus efeitos não visuais no padrão circadiano de seres humanos. Dessa forma, foi realizado um estudo sobre a interferência da iluminacao artificial no ciclo circadiano dos indivíduos, a qual esta intimamente relacionada a regulação de estimulos, tais como, períodos vigília-sono, apetite, relaxamento, alerta, entre outros. Um ponto interessante, e que, ate pouco tempo, partindo do ponto de vista do projeto luminotecnico, a relação entre o sistema endócrino, responsável por regular os hormonios no corpo humano, e a iluminação era pouco considerada. Entretanto, recentemente, estudos indicam uma forte relacao entre o bom funcionamento deste relógio biológico e à variação de temperaturas de cores da luz natural durante o dia. Sendo assim, em meio a um contexto o qual tecnologias novas estão sendo criadas e difundidas a cada dia, as pessoas estão cada vez mais expostas a utilização de iluminação artificial por meio de aparelhos eletronicos. E, salvo algumas excessões lançadas recentemente no mercado, tais aparelhos não possuem a capacidade de configurar a variacao da temperatura de cor durante o dia, ocasionando alterações no ciclo circadiano e consequentemente na saúde dos usuários do ambiente. Portanto, além de estudar a interferência da iluminação artificial, o trabalho visa indicar soluções para minimizar os efeitos da iluminação noturna residencial afim de melhorar a saúde e a qualidade de vida dos usuários, por meio de soluções fáceis de serem adotadas. Dessa forma, é imperativo que além de projetar ambientes bem iluminados, realçando os elementos do espaço, exista a preocupaçao por parte dos arquitetos e profissionais do ramo em projetar ambientes que proporcionem qualidade de vida as pessoas, salientando a necessidade de se pensar na iluminação artificial voltada para com enfoque no ritmo biológico dos usuários, cada vez mais orientado para o ser humano, influenciando positivamente na saúde. Palavras-chave: Ciclo circadiano. Iluminação. LED Azul. Luz e saúde. Melatonina. 1. Introdução Para Feldman (2007:19) a arquitetura se enquadra dentro das ciências sociais onde os aspectos qualitativos constituem parte fundamental do estudo e deliberações visando a qualidade de vida das pessoas concomitantemente com a própria natureza. Sob a perspectiva da qualidade da iluminação do ambiente residencial, os controles poderiam ser aproveitados para aumentar a flexibilidade, funcionalidade e estética de um ambiente. A luz é fundamental ao homem e sem ela não há vida. A luz é radiação eletromagnética capaz de sensibilizar o olho humano. Os seres humanos que possuem 100% da visão ou algo próximo a isso, são pessoas menos dependentes dos outros sentidos: paladar, audição, tato e olfato, quando comparados a indivíduos que apresentam diferentes estágios de perdas

La nuit n’est pas un espace-temps inexploré par le géographe [Deleuil, 1994 ; Fiori, 2000 ; Mosser et Devars, 2000 ; Paquot, 2000 ; Gwiazdzinski, 2002, 2005 ; Mos- ser, 2003, 2005, 2007 ; Mallet, 2009], mais il reste jeune et nécessite donc d’être observé, afin d’être cerné, dans une globalité parfois déroutante, mais souvent sti- mulante. Si la nuit, et plus spécifiquement la nuit urbaine, a effectivement été ap- préhendée par le chercheur, il s’agit souvent – encore aujourd’hui – d’analyser comment cet espace-temps peut être optimisé dans ses différents usages, notamment par la lumière artificielle qui les accompagne. Prenant le contre-pied de ces démarches, nous proposons ici de montrer le renversement qui s’opère actuelle- ment quant aux considérations de cette lumière artificielle, la faisant passer du statut quasi-exclusif de progrès technologique à celui d’une source de gêne, de nuisance, voire même de pollution.