Fluorescent Lighting Fixtures Research Articles

The Role of the Interior Designer in the Autistic Classroom: Location and Material Selection are Essential for Success

The importance of location, lighting, and furniture finishes are three areas an interior designer cannot overlook. This presentation stems from a dissertation on the importance of multi-sensory room usage in elementary schools. The researcher found that the location of the autistic classroom is one of the most important aspects that is often overlooked by both school leaders and the architects who design schools. Natural lighting should also not be ignored as it helps support healthy circadian rhythms and can be a source of sensory regulation and an opportunity for stimming. Lighting can be detrimental to those with special needs due to the subtle flickering of fluorescent light fixtures, which may not be noticed by the typical person but can be bothersome and interrupt a child with specific sensory issues. Lastly, acoustics, color, and material and furniture selections are critical when designing for students under the autism spectrum. Acoustic control helps to minimize background noise and echo by specifying materials to absorb sound and eliminate reverberation. Research has resulted in a color palette that students on the spectrum respond well to in addition to the importance of seating choice variation within the classroom. Lastly, visual and tactile characteristics of selected materials are vital to satisfy the sensory needs of the students while eliminating unnecessary distractions within the classroom.

A Clinical Study Comparing the Maxillary Anterior Tooth Shade and Fabricated Crown Shade of the Western Uttar Pradesh Population to Commercial Shade Guides.

Background It is essential for dentists and technicians to work together to fabricate and create restorations that are a "perfect" shade match for a particular person. Thus, the Vitapan 3D-Master tooth shade system (Vita Zahnfabrik, Germany) was created and put into use in order to improve the accuracy of shade-selection operations. The objective was to visually assess the color of the maxillary anterior teeth in male and female subjects from various age groups in Uttar Pradesh, India. Materials and methods There were 150 patients in total, and they were divided equally into three groups of 50: Group I, which included patients aged 18 to 30; Group II, which included patients aged 31 to 40; and Group III, which included patients aged 41 to 50. Ceiling-mounted fluorescent lighting fixtures with PHILIPS 65 D tubes (OSRAM GmbH, Germany) were installed. Three medical experts provided their opinions as part of this research. The maxillary central incisor was placed next to tabs of various shades, and the doctors' final assessment was based solely on the central one-third of the face. From each of the two sample sets, a total of 30 patients were selected. Once the crown had been made from the prepared tooth of the patient, it was colored according to two shade guidelines (Vita Classic and Vita 3D Master). The three clinicians matched the shade of the manufactured crown with visual shade guides. For shade matching, a modified United States Public Health Service (USPHS) standard was employed. Results The Chi-square test was used to compare categorical variables across groups. According to the Vitapan Classic shade guide, 26% of Group I participants matched the first Hue group (A1), 14% of Group II participants matched the first Hue group (A3), and 20% of Group III participants matched the second Hue group (B2). Master shade guide for Vita 3D 26% of Group I participants matched with the second value group (2M2), 18% of Group II participants matched with the third value group (3L 1.5), and 24.5% of Group III participants matched with the third value group (3M2). Eighty percent of people who were matched to Alpha scored for crowns made using the Vita 3D Master shade guide, while 94.1% of people who were matched to Charlie scored for crowns made using the Vitapan Classic shade guide in a comparison of the two shade guides. Conclusion The majority of the shades obtained from the Vita 3D master shade guide were found to be 1M1 and 2M1 in the younger patients, 2M1 and 2M2 in the second age group, and 3L 1.5, 3M2 in the older age group. In contrast, the Vitapan Classic shade guide revealed A1, A2, A3, B2, C1, D2, and D3 as the predominant shades.

TOXIC EFFECTS OF AROCLOR 1254 ON RAT HEART AND THYROID AND MODIFYING ROLE OF SELENIUM STATUS

Objective: Polychlorinated biphenyls (PCBs) were very widely used in industrial products in past. These chemicals were banned in the 1970s due to their toxic effects. PCBs can still affect human health, as they are persistent in the environment. Aroclor 1254 (A1254) is a commercial PCB congener which was used in electrical transformers, fluorescent lighting fixtures and old appliances such as televisions or refrigerators. In this study, we aimed to evaluate the toxic effects of A1254 on heart and thyroid in male Sprague-Dawley rats. In addition, the modifying role of selenium status was also evaluated.
 Material and Method: 8-week-old male Sprague-Dawley (SD) rats were used in the experiment. The animals were separated randomly into 6 groups (n=6) as control; selenium supplemented (SeS); selenium deficient (SeD); A1254 exposed (A); selenium supplemented A1254 exposed (ASeS) and selenium deficient A1254 exposed (ASeD). A1254 was applied by gavage during the last 15 days of feeding period. Heart and thyroid weights and relative weights, plasma thyroid hormone levels, as well as thyroid and heart tissue oxidative/antioxidative parameters were evaluated.
 Result and Discussion: Results showed that A1254 exposure and selenium deficiency caused oxidative stress on both heart and thyroid. Plasma fT3 and fT4 levels markedly changed in ASeD group. In conclusion, it can be stated that A1254 exposure can cause lead to oxidative/antioxidative imbalance in both thyroid and heart and can disrupt functioning of thyroid hormones. Selenium seems to have a modifying role in A1254 toxicity in both organs, the importance of which should be evaluated with further mechanistic experiments.

소규모 개인 사무소 공간의 조도증감에 대한 조명사용자의 시각적 만족도 예측

초록 · 키워드 목차 오류제보하기 This study examines the effects of illuminance fluctuations on occupants" visual perception and comfort in a small private office. Experiments were conducted in an actual office space, where six fluorescent lighting fixtures were installed and no daylight was available. Twelve healthy college students participated and five fluctuation ranges were applied to the 500 lx of task illuminance on desktops. Reading tasks using a computer and monitor were conducted, while the experiments were performed. Results imply that the level of visual satisfaction was impaired noticeably as the fluctuation ranges increased. The fluctuation range of desktop illuminance should be maintained within 63.34 lx to guarantee visual satisfaction. The perception for visual distraction and stimulus showed a similar tendency as the fluctuation ranges varied. In order to avoid the visual sensation for distraction and stimulus, the fluctuation ranges should be within 97.21 lx and 104.59 lx, respectively. Regression results indicate that the perception for visual satisfaction was affected by the perception for visual distraction, visual stimulus and visual warmness. The visual distraction was the strongest influential factor to the visual satisfaction. The increase of mean vote by 1 on the voting scale led to the decrease of visual satisfaction by 0.441 on the voting scale. #Illuminance #Visual perception #Office #Fluorescent lighting #Fluctuation range #Visual satisfaction Abstract1. 서론2. 연구 방법3. 결과 및 고찰4. 결론 및 향후 연구REFERENCES

A case study comparing the influence of LED and fluorescent lighting on early childhood student engagement in a classroom setting

Studies suggest that the learning environment can act as a third teacher in contributing towards student academic success. A variable within the physical learning environment that has received little attention in the literature is the interior lighting. Because of budget constraints and age, most American public school classrooms have fluorescent lighting fixtures installed. A new lighting technology, Light Emitting Diodes (LEDs), is becoming popular in commercial facilities across the United States because of energy efficiency. Previous research has demonstrated that lighting influences adult worker productivity and mood in a workplace. However, because children process stimuli faster, it is unknown whether LED lighting would have the same influence in a learning environment. Researchers hypothesise that students display more engaged behaviours in classrooms lit with LEDs as compared with fluorescent lighting fixtures. The current study tested this hypothesis by observing child engagement behaviours in a pre-K classroom under LED lighting and fluorescent lighting fixtures to compare differences. Students displayed more engaged behaviours under the LED lighting condition.

Radio Spectrum Pollution: Facing the Challenge of a Threatened Resource

On November 14, 2013, the Silicon Flatirons Center hosted the conference “Radio Spectrum Pollution: Facing the Challenge of a Threatened Resource” at the University of Colorado Law School. Intensive use of radio frequencies by wireless systems is crucial to our economic and social wellbeing and to national defense and homeland security. Successful operation is essential for a wide variety of wireless applications, ranging from simple keyless entry systems and garage door openers, to broadcasting networks, Wi-Fi and cellular networks, complex navigation systems like GPS and radar, and mobile radio systems relied upon by first responders. By analogy to other important economic inputs like coal, water, and know-how, one can think of radio frequencies - also known as spectrum - as a resource. The proliferation of wireless devices along with the increasing amount of frequency capacity consumed by each device (e.g. tablet computers used to upload or download video programming) puts intense pressure on the resource - a topic addressed at previous Silicon Flatirons events. The good news is that, unlike other important natural resources such as oil, coal, or natural gas, the spectrum resource is not destroyed by use - it is infinitely renewable. However, like air and water, the spectrum resource can be polluted. In spectrum, pollution takes the form of interference from other radio sources. Since the performance of a radio link depends upon the strength of the desired signal relative to the strength of undesired interfering signals, increased background radio noise can reduce the total carrying capacity of the resource. When severe, the noise pollution manifests itself, for example, in the form of hissing or popping on radio channels, picture loss on television or other video feeds, interrupted wireless voice conversations, slow or intermittent internet connections, and - in extreme cases - degradation of communication and navigation systems that are vital to national security and homeland defense. This conference focused on radio frequency noise rather than interference in general, of which noise is a subset. In general usage, “noise” means energy (electromagnetic or sonic) that some particular person finds unwelcome given their activities. However, the conference and this report use the following more circumscribed definition: noise is radio frequency interference that does not come from an identifiable, intentional radiator. Three broad sub-categories of noise are: (1) Natural (not man-made) environmental noise, e.g. from lightning and atmospheric processes (most important at lower frequencies). (2) Interference from unintentional radiators, e.g. switching power supplies in fluorescent and LED light fixtures (often called “man-made” noise to distinguish it from the first category). (3) Aggregate out-of-band interference from a “sea” of intentional radiators, e.g. out-of-band emissions (OOBE) from hundreds or thousands of nearby transmitters leaking into noise-limited services like satellite or radar receivers. While there are regulations at the international and national level aimed at controlling man-made sources of interference, they are becoming more important because of the increasing number of devices involved, the close proximity within which they must operate, and the increasing importance of wireless services. Since the level of aggregate radio noise from both natural and human sources tends to decrease as frequencies become higher, the intense interest in noise levels back in the days of short- and medium-wave radio has declined with the shift of critical wireless systems to higher frequencies. However, evidence is emerging that the radio noise floor is rising in higher-frequency bands that are especially important to both commercial and public safety applications. This conference brought together academics, policymakers, spectrum users, and advocates to examine the extent of, and trends in, radio noise pollution and to explore how the associated policies and regulations may need adjustment to reflect changes in radio noise levels.

Development of an intelligent lighting system using LED ceiling lights into an actual office

AbstractAs a demonstration, our proposed system has been introduced into actual offices in Tokyo. It consists of fluorescent lighting fixtures, light control units, microprocessors, illuminance sensors, and distributed optimization software. The lower control limit of a fluorescent light fixture is between 20% and 30%. We measured the relationship between the color temperature and the dimming range for the illuminance. The experimental results showed that the dimming range for the illuminance was narrow. To provide each worker's desired illuminance and color temperature, an LED ceiling light which can control the luminance between 0% and 100% is preferable. However, LED ceiling lights for office use have not been developed so far. The two leading light equipment makers have prototyped LED ceiling lights. We developed an intelligent lighting system using these lights and verified its effectiveness. The experimental results showed that the proposed system could provide the required illuminance and color temperature, and could achieve an energy savings of 60 to 80%. The intelligent system has a high affinity for LED lights. From the point of view of effective utilization of energy, the intelligent lighting system using LED ceiling lights showed good performance. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(10): 54–63, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10395

Life cycle cost analysis of building re-lamping alternatives

With rising energy costs and cuts in expenditures, institutions around the country are trying to find ways to cut energy consumption and operational costs. As many academic institutions have old buildings in service, one of the most considered and relatively easy energy saving alternatives is to change old and inefficient lighting to those that are newer and more energy efficient. This paper deals with the cost savings question of re-lamping existing buildings on the campus of the University of Illinois at Urbana-Champaign using life cycle cost procedures. We examined the energy and costs savings potential by comparing existing prevalent T12 fluorescent lighting fixtures to two T8 fixtures and two T5 fixtures. The results show that, although there may be energy savings potential for some of these newer systems, the economic benefits are not always obvious or real.

소규모 사무실의 조명 색 변화에 따른 시각적 감지 및 무드 변화 분석

This study examines the influences of correlated color temperature and illuminance on visual perception and temporary mood sensation in a small office. Field measurements and surveys were conducted in a full-scale mock-up model. Twenty subjects participated in the survey under six lighting conditions formed by three color temperature and two illuminance levels. Results indicate that 4000 K color temperature was effective to mitigate glare sensation from light source. Lamps with low color temperature such as 2700 K was not recommended for office lighting since they are likely to caused glare and visual discomfort. Preferred color temperature was 4000 K and 6500 K for 750 lx and 500 lx target illuminance respectively. The increase of illuminance was not an effective contributor to improve mood perception. The illuminance should be lower than 500 lx to achieve good mood, but the illuminance level in office space should be considered with visual performance simultaneously. This study suggests that fluorescent lighting fixtures with 4000 K lamps would be usefully used for office lighting since they formed friendly conditions for better visual performance.

A Driving Technology for Retrofit LED Lamp for Fluorescent Lighting Fixtures With Electronic Ballasts

A driving technique that can operate with electronic ballasts for fluorescent lamps to drive LEDs without requiring the replacing of any electronic ballast circuitry or modifying the existing infrastructure of a lighting network is presented. This technology provides an eco-friendly and immediate solution to turn a lighting system with fluorescent lamps into the one with LED lamps. The proposed technology is based on controlling the input impedance of an ac/dc converter, which is connected to the output of the ballast, and converting the high-frequency ac power from the ballast into dc power for the LEDs. With such adjustable input impedance, the active and reactive power drawn from the ballast can be controlled. The power supplying to the LED lamp, and thus its brightness, can be adjusted independently by an external means, such as wireless control. An experimental LED lamp prototype for retrofitting a 36-W T8 fluorescent lamp has been built. It is studied together with a fluorescent lamp and with both lamps ballasted by a commercial nondimmable electronic ballast for dual fluorescent lamps. The light output of the LED lamp can be varied from 100% to 51% of full brightness, while the light output of the fluorescent lamp remains unchanged. The input power to the ballast is reduced by 26% over the dimming operation of the LED lamp. A comprehensive study into the electrical performance of the ballast, operational characteristics of the two lamps, system efficiencies, and light outputs under different dimmed conditions is presented.

Development of the Intelligent Lighting System using LED Ceiling Lights into an Actual Office

As a demonstration, this system has been introduced into actual offices in Tokyo. These systems consist of fluorescent lighting fixtures, light control units, microprocessors, illuminance sensors and distributed optimization software. The lower control limit of a fluorescent light fixture is between 20% and 30%. We measured the relationships between color temperature and a dimming range of illuminance. The experimental results showed the dimming range of illuminance was narrow. To provide each worker's desired illuminannce and color temperature, the LED ceiling light, which can control the luminance between 0% and 100%, is desired. However, the LED ceiling light for the office use has not been developed so far.The two leading lighting equipment makers prototyped the LED ceiling lights. We developed the intelligent lighting system using these lights, and verified its effectiveness. The experimental results showed the proposed system could provide required illuminance and color temperature, could make energy saving of 60-80%. The intelligent system has high affinity with a LED light. From the point of view of effective utilization of energy, the intelligent lighting system using the LED ceiling lights showed a good performance.

Efficient Dual-Function Solar/Electric Light Guide to Enable Cost-Effective Core Daylighting

As a component of our cost-effective core daylighting research program, we have developed a hollow light guide that can be used to distribute sunlight collected by a heliostat device, and can also operate as an efficient fluorescent light fixture when the sunlight is insufficient to illuminate the workspace. This dual-function prism light guide structure has a cross-section that is similar to standard commercial fluorescent light fixtures, but with an increased depth in order to pipe the sunlight. The bottom surface of the guide is lined with a thin polycarbonate film having prismatic surface features, while the top and sides are lined with a highly-reflective multilayer optical film having a luminous reflectance greater than 98 percent. The angular constraints of the concentrated sunlight, combined with the high reflectance of the surfaces, enable the sunlight to be efficiently transported within the guide along a distance of greater than 10 m. The guide can also illuminate the room using electric sources, since the light from the lamps strikes the prismatic bottom surface at angles for which it is an efficient transmitter. Photometric characterization of the new dual-function guide has been performed, resulting in illuminance levels, uniformity and efficiency values well within recommended standards. The dual-function design approach has yielded a daylighting system that can be cost-effectively incorporated into standard office building construction.

PCBs Are Endocrine Disruptors: Mixture Affects Reproductive Development in Female Mice

Polychlorinated biphenyls (PCBs) are a broad group of chemicals that includes 209 aromatic chlorinated hydrocarbons used for products ranging from fluorescent light fixtures to coolant fluids inside parts of consumer electronics. Short-term exposure to large amounts of PCBs can cause liver damage; the effects of smaller concentrations can be more subtle, affecting the reproductive development of children of exposed mothers. But are these compounds actually endocrine disruptors? New work by researchers at the Mount Sinai School of Medicine confirms that they can be, and for the first time connects a molecular mechanism to the lifelong phenotypic changes seen after exposure to environmental estrogens [EHP 114:898–904; Ma and Sassoon]. Sold predominantly as mixtures under the trade names Aroclor and Pyranol, PCBs have been banned in the United States since 1977 and are out of use or highly restricted throughout much of the world. These compounds, which are fat-soluble and structurally similar to DDT, are highly stable: PCBs made and used for nearly 50 years before the ban remain in the environment and are found throughout the food chain, including in human tissues and breast milk. The researchers tested the hypothesis that PCBs are endocrine disruptors by comparing their effects on expression of Wnt7a in mice. Down-regulation of Wnt7a is a known factor in the reproductive deficits found in mice exposed to diethylstilbestrol (DES), a synthetic estrogen once used to supplement estrogen levels in pregnant women. After exposure to DES, development of the reproductive system is impaired when production of the regulatory protein coded by Wnt7a is temporarily squelched. A passing loss of appropriate regulation in very young animals leads to reproductive changes—for example, in the number of uterine glands or the thickness of the myometrium, the uterus’s muscular outer layer—that give way to more pronounced changes through life. This suggests that exposed organisms are sent down an abnormal developmental path from which they cannot return. Using in situ hybridization, immunohistochemistry, and quantitative reverse-transcriptase polymerase chain reaction, the authors showed that the effects of environmentally relevant levels of Aroclor 1254, a commercial mix of PCBs, were similar but not identical to those of low levels of DES. Both led to decreases in expression of the Wnt7a regulatory gene and showed qualitative changes in uterine development like those described above. The authors also demonstrated that measurement of Wnt7a provides a molecular tool that lays to rest any doubt that PCBs are endocrine disruptors. The authors further showed that genetic makeup matters in terms of vulnerability to endocrine disruption. Mice with only one good copy of the Wnt7a gene were more sensitive to DES or PCBs than mice with both copies intact, providing a concrete example of how gene variation can leave some individuals more susceptible than others to the effects of PCB exposure.

주광(晝光) 대등형 가변조명(可變照明) 제어설비의 적용 및 통합성능

에너지 절약형 광원의 대체와 아울러 최적 운용 기술의 개발만이 건축조명부분에 대한 에너지 절약의 잠재력을 현실화 시킬 수 있다고 판단된다. 광원의 효율을 향상시키는 것은 기술적인 한계와 많은 개발시간이 요구되는 반면에 조명제어의 최적화 기술은 많은 기술이 개발되어 사용되고 있는 상황이므로, 보다 지능적이고 복합적인 시스템 차원에서 효율을 높이기 위한 노력들이 이루어지고 있다. 특히 상업용 건물이나 사무소건물에 있어 고효율 형광등과 전자식 안정기의 도입이후에 에너지 절감방안의 대표적인 것은 조명제어라고 인식하고 있다. 본 연구에서 분석한 일반적인 사무소 공간의 경우, 주광과 인공조명을 통합제어할 때 담천공 조건에서 소등할 수 있는 주광의 유효입사 거리는 창측에서 약 4[m]에서부터, 시간대에 따라 5[m]에 이르는 것으로 나타났다. 이는 실내에 설치된 인공조명기구의 약 60[%] 이상이 소등될 수 있어 동일한 비율의 조명 에너지가 절감될 수 있는 잠재력을 나타낸다. 입사각과 태양광량의 상호 보완적 특성으로 인하여 주간 내내 일정한 주광의 유효거리가 확보되는 것으로 나타났다. 계절별 소등라인축의 이동범위는 실내에서 자연의 변화를 느끼게 해주는 정도의 바람직한 것으로 허용될 수 있을 것이며, 자연광에 가까운 광색을 가진 광원을 사용함으로써 쾌적한 조명을 유지할 수 있을 것이다.

The fire performance of electrical insulating materials used in fluorescent lighting fixtures

AbstractAnalysis of a major fire incident at a home furnishings warehouse led to the conclusion that extended exposure of electrical insulating materials composing a lampholder in a fluorescent lamp were the initial items ignited. It was thought that these items, composed of thermoset polymers, were ignition‐resistant materials. However, analysis showed that thermally induced degradation caused the material to degrade into an easily ignited, char‐like residue. The parent polymer, highly cross‐linked urea formaldehyde, had been initially cast into the lampholder configuration to prevent high voltage conditions and arcing.Thermal and elemental analyses as well as the investigation conducted at the fire site, helped to determine that the original polymer had pyrolysed into a residue differing in both chemical composition — reduced hydrogen and oxygen content — and physical characteristics when compared with the parent material. The changes in the chemical and physical properties of the original polymer explain the observed thermal inertia of the residue and its tendency to smolder (as opposed to the ‘parent polymer’). They are characterized by (1) an increased accessibility to oxygen, (2) reduced thermal conductivity and (3) increased proportion of carbon. Copyright © 2002 John Wiley & Sons, Ltd.

Energy efficiency and the environment: the potential for energy efficient lighting to save energy and reduce carbon dioxide emissions at Melbourne University, Australia

In this study, the potential to improve the energy efficiency of lighting systems at Melbourne University was assessed. The cost effectiveness of different lighting technology alternatives was also calculated. Electricity used by existing 1.2 metre fluorescent lighting fixtures and four energy efficient lighting technology alternatives was compared. Relative to the existing system, installation of the four lighting technology alternatives would result in energy savings of 13.9%, 20.5%, 24.4% and 64.9%, respectively. If the technology alternative that saved the most electricity was installed, carbon dioxide emissions associated with the University's electricity use would be reduced by about 10%. Economic analysis shows that overall, none of the four technology alternatives are cost effective, although fine scale analysis shows that one technology alternative is cost effective in two out of the five room categories that were examined. Three barriers to the cost effective installation of energy efficient lighting technologies at Melbourne University are identified: (a) low lighting system operating hours, (b) the low cost of electricity and (c) the high cost of energy efficient lighting components.

Commercial Lighting Innovations

ABSTRACT In our quest for finding ways to reduce the life cycle costs of Navy ships, the Affordability Through Commonality (ATC) project has investigated several commercial lighting innovations. This paper will discuss two particularly noteworthy commercial products that have been selected for further evaluation on board Navy ships: specular reflectors for fluorescent lighting fixtures and the Solar 1000 sulfur light source.Specular reflectors are designed to dramatically increase the amount of light reflected from a fluorescent fixture resulting in one or more of the following benefits: increased task lighting, reduced maintenance and consumable costs (fewer bulbs), reduced acquisition and alteration costs (fewer fixtures), and reduced energy use. Specular reflectors are sized for the specific type of fluorescent fixture and can be designed and formed to provide general or directed task lighting. They are inexpensive and can be installed easily and quickly.The Solar 1000 sulfur light source is the first in a planned family of very bright, energy‐efficient, electrodeless lamps using sulfur bombarded by microwaves to produce illumination in a continuous range of wavelengths very close to sunlight. It is ideal for remote source lighting distribution systems such as light tubes and fiber optics. This innovation in lighting has been heralded by the Department of Energy as “a revolutionary 21st century lighting system.”

Task Lighting for the Work Surface: The Problem of Reflected Glare

Some of the “qualitative” aspects of task lighting for horizontal work surfaces are examined. By means of graphic and photographic analyses of the cause and effect of reflected glare, the problems associated with the standard strip fluorescent task light fixtures are shown. Today's lighting designer is able to provide improved visibility in work environments through the use of a different concept of light source location using fixtures designed around the new compact fluorescent lamps, introduced in the 1980s.