Riad Saraiji

Bio: Riad Saraiji is an academic researcher from United Arab Emirates University. The author has contributed to research in topics: Contrast (vision) & Facade. The author has an hindex of 7, co-authored 18 publications receiving 204 citations. Previous affiliations of Riad Saraiji include Pennsylvania State University & British University in Dubai.

Modular lighting system for product display unit

Abstract: A lighting system includes an illumination source arranged within a housing wherein the housing is positioned at a front end portion of a shelf of a product display unit. In a preferred form of the invention, thermal insulation is disposed between the housing and the shelf such that the shelf is thermally isolated from heat generated by the lighting unit. The lighting unit can be attached to or formed integral with the front portion of the shelf so as to act as an extension thereof or arranged beneath the shelf, preferably with an air gap or other type of thermal material barrier therebetween. In accordance with a preferred embodiment of the invention, the lighting unit takes the form of an elongated housing which is slidably mounted within a label receiving area of a shelf. The invention also contemplates lighting upper and lower shelves with a single lighting unit and providing the light housing with a label receiving area, which can be lit, to provide consumers with information concerning products to be supported on the shelf.

Lighting system employing bi-directional optics for illuminating product display unit

Abstract: A modular lighting system for illuminating products supported upon various vertically arranged shelves of a display unit includes a housing attached to a first shelf, with the housing including at least one transparent panel which permits an internal illumination source to light products supported upon at least one of the first shelf, a shelf arranged directly above the first shelf and a shelf disposed directly below the first shelf. Most preferably, the light illuminating from the housing is directed so as to effectively, entirely illuminate product support surfaces associated with both the first shelf and the shelf directly below such that the display of products supported anywhere from the front to the back of these shelves is enhanced. This front-to-back lighting function can be achieved in various ways, such as by employing direct, reflective and refractive lighting techniques.

Light Pollution Index (LPI): An Integrated Approach to Study Light Pollution with Street Lighting and Façade Lighting

Abstract: Rather than being complementary, street lighting and facade lighting are typically designed independently of each other. As a result, light from street lighting luminaires might spill onto building facades and influence characteristics of the facade lighting including required light levels and color. Conversely, facade lighting might reflect onto the street and contribute to the street illumination. This manuscript presents an integrated approach to analyzing the interaction between the street and facade lighting in consideration of light pollution control. A generic street model with various calculation grids was studied. It was found that a moderately lit facade contributes to a horizontal illuminance of 5 lux or more on the street and a vertical illuminance of 4 lux or more 1.5 m above the sidewalk. An over-illuminated street may result when both street and facade lighting exist without reference to each other. The size of the light-pollution calculation grid and the use of a 3-D illuminance gr...

Multiple door display merchandiser with lighting enhancement

Abstract: The display space of a multiple door display merchandiser is illuminated by one or more vertically extending lamps (80) disposed intermediate the vertical sides of an access opening to the display space. A multiple door assembly (44) covers the access opening. To enhance the illumination of the display space, a pair of vertically extending side reflectors (92) are provided, one extending alon one side of the access opening and the other extending along the other side of the access opening. An additional reflector may be mounted to an interior facing surface of the door along an upper front region of the door and/or a lower front region.

Dominant contrast as a metric for the lighting of pedestrians

Abstract: CIE Publication 115 and ANSI/IESNA Recommended Practice 8-00 both use vertical illuminance 1.5 m above the ground as a design criterion for the lighting of pedestrians. While vertical illuminance h...

Human Factors in Lighting

Abstract: When I began to study lighting engineering, my professor told me I was about to enter a magnificent community of about 3000 people distributed around the world, and in just five years from then I w...

Thermal management of LEDs: Package to system

Abstract: Light emitting diodes, LEDs, historically have been used for indicators and produced low amounts of heat. The introduction of high brightness LEDs with white light and monochromatic colors have led to a movement towards general illumination. The increased electrical currents used to drive the LEDs have focused more attention on the thermal paths in the developments of LED power packaging. The luminous efficiency of LEDs is soon expected to reach over 80 lumens/W, this is approximately 6 times the efficiency of a conventional incandescent tungsten bulb. Thermal management for the solid-state lighting applications is a key design parameter for both package and system level. Package and system level thermal management is discussed in separate sections. Effect of chip packages on junction to board thermal resistance was compared for both SiC and Sapphire chips. The higher thermal conductivity of the SiC chip provided about 2 times better thermal performance than the latter, while the under-filled Sapphire chip package can only catch the SiC chip performance. Later, system level thermal management was studied based on established numerical models for a conceptual solid-state lighting system. A conceptual LED illumination system was chosen and CFD models were created to determine the availability and limitations of passive air-cooling.

Display cabinet illumination

Abstract: An illuminator (1) has two lines of LEDs (2) on inwardly-directed faces (7) of an elongate body (3) which forms a mullion for a display cabinet. Heat conduction through the body (3) to outer surfaces provides the durable effect of anti-sweat heating to prevent condensation in doors of the cabinet.

Limitations in drivers' ability to recognize pedestriansat night

Abstract: This study quantified drivers' ability to recognize pedestrians at night. Ten young and 10 older participants drove around a closed road circuit and responded when they first recognized a pedestrian. Four pedestrian clothing and two beam conditions were tested. Results demonstrate that driver age, clothing configuration, headlamp beam, and glare all significantly affect performance. Drivers recognized only 5% of pedestrians in the most challenging condition (low beams, black clothing, glare), whereas drivers recognized 100% of the pedestrians who wore retroreflective clothing configured to depict biological motion (no glare). In the absence of glare, mean recognition distances varied from 0.0 m (older drivers, low beam, black clothing) to 220 m (722 feet; younger drivers, high beam, retroreflective biomotion). These data provide new motivation to minimize interactions between vehicular and pedestrian traffic at night and suggest garment designs to maximize pedestrian conspicuity when these interactions are unavoidable.

Lens generating a batwing-shaped beam distribution, and method therefor

Abstract: A lens to redirect light, having an angular distribution centered around a left-right symmetry plane (LRSP), from a light source. The lens includes an incident face, facing the light source, which includes an incident corner, which divides the incident face into incident inner and outer zones and is concave, forming an obtuse angle in air. The lens also includes an opposite exiting face, which similarly includes an exiting corner, which similarly divides the exiting face. Each ray striking the incident inner zone transmits through the lens, striking the exiting inner zone. Each ray striking the incident outer zone transmits through the lens, striking the exiting outer zone. Each ray striking the incident face, transmits through the lens, strikes the exiting face, and refracts out of the lens, has initial and final propagation angles with respect to the LRSP. The final propagation angle is greater than the initial propagation angle.