A Simple Method to Improve VCP by Reducing DGR in an Interior Lighting Installation

2018 ◽  
pp. 73-81
Author(s):  
Madjidi Faramarz ◽  
Abedi Kamal ad-Din
Keyword(s):  
Surface Area ◽  
Main Role ◽  
Visual Comfort ◽  
Lighting System ◽  
Simple Method ◽  
Evaluation Systems ◽  
Interior Lighting ◽  
Modified Equations ◽  
Comfort Perception ◽  
Discomfort Glare

Discomfort glare rating (DGR) and Unified glare rating (UGR) are main models currently used as discomfort glare evaluation systems, both of which are calculated employing four factors including the luminaire size, the luminaire position relative to the observer, background luminance, and the luminaires number and location. This study aims at proposing a simple solution for reducing DGR and thereby increasing visual comfort perception (VCP) in an interior lighting system. The proposed solution is based solely on variations of luminaire surface area without change in other factors, e.g. candlepower and number and location of luminaires in the lighting system. To this end, firstly, the equations related to DGR were modified for a desired luminaire, and, secondly, by solving the modified equations, the new luminaire surface area was obtained, which caused DGR decrease and VCP improvement. Finally, by some modifications in the location of selected luminaires having main role on DGR, the VCP rose considerably.

scholarly journals Tuning the hierarchical pore structure of graphene oxide through dual thermal activation for high-performance supercapacitor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeongpil Kim ◽  
Jeong-Hyun Eum ◽  
Junhyeok Kang ◽  
Ohchan Kwon ◽  
Hansung Kim ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Pore Structure ◽  
Specific Capacitance ◽  
Surface Area ◽  
Thermal Annealing ◽  
High Performance ◽  
Annealing Process ◽  
Supercapacitor Electrode ◽  
Simple Method ◽  
Surface Areas

AbstractHerein, we introduce a simple method to prepare hierarchical graphene with a tunable pore structure by activating graphene oxide (GO) with a two-step thermal annealing process. First, GO was treated at 600 °C by rapid thermal annealing in air, followed by subsequent thermal annealing in N2. The prepared graphene powder comprised abundant slit nanopores and micropores, showing a large specific surface area of 653.2 m2/g with a microporous surface area of 367.2 m2/g under optimized conditions. The pore structure was easily tunable by controlling the oxidation degree of GO and by the second annealing process. When the graphene powder was used as the supercapacitor electrode, a specific capacitance of 372.1 F/g was achieved at 0.5 A/g in 1 M H2SO4 electrolyte, which is a significantly enhanced value compared to that obtained using activated carbon and commercial reduced GO. The performance of the supercapacitor was highly stable, showing 103.8% retention of specific capacitance after 10,000 cycles at 10 A/g. The influence of pore structure on the supercapacitor performance was systematically investigated by varying the ratio of micro- and external surface areas of graphene.

A field study of fluorescent and LED classroom lighting

2016 ◽  
Vol 50 (4) ◽  
pp. 631-650 ◽  
Author(s):  
N Gentile ◽  
T Goven ◽  
T Laike ◽  
K Sjoberg
Keyword(s):  
Secondary School ◽  
Field Study ◽  
Energy Savings ◽  
Electricity Consumption ◽  
Visual Comfort ◽  
Lighting System ◽  
Upper Secondary ◽  
Lighting Systems ◽  
Indoor Lighting ◽  
Academic Year

Indoor lighting is facing a massive retrofit to LED lighting. Research is needed to assess whether LED-based lighting can promote energy efficiency, boost visual comfort and support biological functions. This field study considered the lighting of four identical classrooms in an upper secondary school in Helsingborg, Sweden. Two classrooms were fitted with state-of-the-art ceiling pendants containing T5 fluorescent tubes and that had a direct/indirect light distribution (the control rooms). The other two classrooms were fitted with an experimental LED indirect lighting system (the experimental rooms). In the classrooms, 72 students aged 17–18 years performed their usual educational activities over a whole academic year. The light environment, electricity consumption, and students’ mood, light perception and saliva cortisol concentration were monitored. The two lighting systems produced only marginal differences. Overall, the experimental rooms were slightly preferred but achieved only small energy savings due to high parasitic losses.

A dynamic vertical shading optimisation to improve view, visual comfort and operational energy

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mahdi Valitabar ◽  
Mohammadjavad Mahdavinejad ◽  
Henry Skates ◽  
Peiman Pilechiha
Keyword(s):  
High Performance ◽  
Parametric Design ◽  
Design Method ◽  
Building Energy ◽  
Natural Light ◽  
Visual Comfort ◽  
Content Type ◽  
Operational Energy ◽  
Discomfort Glare ◽  
The Impact

PurposeThe aim of this paper is to present a parametric design method to generate optimum adaptive facades regarding occupants' comfort and building energy criteria. According to the literature review, the following questions have arisen to address the research gaps: Is it possible to have the outside view throughout the whole year without discomfort glare by utilising adaptive solar facades (ASFs)? How can architects integrate both view quality and quantity into ASF design? What is the impact of dynamic vertical shading systems mounted on south facades on the outside view, occupants' visual comfort and operational energy? How can we evaluate the view quantity through multi-layer shading systems?Design/methodology/approachIn recent years, there is a surge in demand for fully glazed buildings, motivating both architects and scholars to explore novel ideas for designing adaptive solar facades. Nevertheless, the view performance of such systems has not been fully explored especially when it comes to the effect of dynamic vertical shading systems mounted on south facades. This fact clarifies the need to conduct more research in this field by taking into account the window view and natural light. Consequently, a simulation research is carried out to investigate the impact of a dynamic shading system with three vertical slats used on the south facade of a single office room located in Tehran, on both view quality and quantity, visual comfort and operational energy. The research attempts to reach a balance between the occupant's requirements and building energy criteria through a multi-objective optimisation. The distinctive feature of the proposed method is generating some optimum shading which could only cover the essential parts of the window area. It was detected from the simulation results that the usage of a dynamic vertical shading system with multi slats for south facades compared to common Venetian blinds can firstly, provide four times more view quantity. Secondly, the view quality is significantly improved through enabling occupants to enjoy the sky layer the entire year. Finally, twice more operational energy can be saved while more natural light can enter the indoor environment without glare. The final outcome of this research contributes toward designing high-performance adaptive solar facades.FindingsThis paper proposes a new metric to evaluate the view quantity through a multi-layer shading system. The proposed method makes it clear that the usage of dynamic vertical shading systems with multi-layers mounted on south facades can bring many benefits to both occupants and building energy criteria. The proposed method could (1) provide four times more view quantity; (2) improve view quality by enabling occupants to watch the sky layer throughout the whole year; (3) slash the operational energy by twice; (4) keep the daylight glare probability (DGP) value in the imperceptible range.Research limitations/implicationsThe research limitations that should be acknowledged are ignoring the impact of the adjacent building on sunlight reflection, which could cause discomfort glare issues. Another point regarding the limitations of the proposed optimisation method is the impact of vertical shading systems on users' visual interests. A field study ought to be conducted to determine which one could provide the more desirable outside view: a vertical or horizontal the view. Research on the view performance of ASFs, especially their impact on the quality of view, is sorely lacking.Originality/valueThis paper (1) analyses the performance of dynamic vertical shadings on south facades; (2) evaluates outside view through multi-layer shading systems; and (3) integrates both view quality and quantity into designing adaptive solar facades.

The photocytotoxicity of different lights on mammalian cells in interior lighting system

2012 ◽  
Vol 117 ◽  
pp. 13-18 ◽  
Author(s):  
Jiayin Song ◽  
Tingting Gao ◽  
Maole Ye ◽  
Hongtao Bi ◽  
Gang Liu
Keyword(s):  
Mammalian Cells ◽  
Lighting System ◽  
Interior Lighting

scholarly journals Salivary and Urine Theophylline Levels in Management of Childhood Asthma

1981 ◽  
Vol 74 (6) ◽  
pp. 415-418 ◽  
Author(s):  
S J Goldsworthy ◽  
M Kemp ◽  
J O Warner
Keyword(s):  
Body Weight ◽  
Surface Area ◽  
Childhood Asthma ◽  
Slow Release ◽  
Simple Method ◽  
Serum Theophylline ◽  
Theophylline Level ◽  
Serum Theophylline Level ◽  
Plasma Theophylline ◽  
Urine Levels

It is not possible to predict the plasma theophylline levels that can be achieved using slow-release aminophylline based on body weight or surface area. Improvement in FEV1 is directly related to increasing serum theophylline level, justifying the need for measuring levels in order to optimize therapy. As repeated venesection in children is unpleasant we have studied a simple method using saliva. Simultaneous blood and salivary theophylline levels correlated sufficiently well for salivary levels to be used for monitoring purposes. Urine levels did not correlate as well, but could be used for checking compliance.

Cross-modal effects of thermal and visual conditions on outdoor thermal and visual comfort perception

2020 ◽  
Vol 186 ◽  
pp. 107297 ◽  
Author(s):  
Cho Kwong Charlie Lam ◽  
Hongyu Yang ◽  
Xia Yang ◽  
Jiarui Liu ◽  
Cuiyun Ou ◽  
...  
Keyword(s):  
Visual Comfort ◽  
Comfort Perception ◽  
Visual Conditions
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