Abstract: An improvement and method for improved structural dynamic stability for 20 and 30 Series Learjets are disclosed. The improvement includes a redistribution of the elevator mass balance to uncouple the elevator rotational motion from the stabilizer translation motion for the higher order horizontal frequencies having node lines in the proximity of the mass outboard counterbalance weights. The original tail section includes a rudder, and a horizontal stabilizer supporting an elevator mounted adjacent the rudder. The elevator includes a proximal end adjacent the rudder and a distal end that includes a counterbalance portion. The improvement includes replacement of an original mass counterbalance weight from within the counterbalance portion with a new mass counterbalance weight of less mass, and the inclusion of additional mass counterbalance weights disposed within the elevator and interposed between the proximal end and the counterbalance portion.

Abstract: An exemplary embodiment provides an air transport that has a scalloped aerodynamic underside that includes at least one depression. The depression is configured to receive at least an upper portion of a cargo pod to preclude an air passage way between an upper surface of a pod and the scalloped underside of the transport. Certain embodiments provide conformal pods that nest into the depressions so that pod under surfaces blend smoothly with the scalloped underside of the transport to provide a smooth aerodynamic underside. The scalloped underside may be retrofitted to existing aircraft or supplied as original equipment on new transports, and may be of composite, plastic or other light weight materials.

Abstract: The invention relates to a seat fixing device, in particular to an air passenger seat on a floor of an aircraft comprising at least one fastening rail (10) in the form or a hollow profile which is provided with a longitudinal channel (14) delimiting the free flanks (16) of the profile on the top part thereof (12) oriented to the scat, wherein said channel comprises through openings (18) disposed in a predetermined modular dimension which enlarge the free input section and are used for inserting at least one snap-locking part (24) of a locking body (26) which is movable to a clamping position with the profile (16) of the hollow profile (14) by the relative displacement of each snap-locking part (24) in a perpendicular direction with respect to the longitudinal axis (28) of the fastening rail (10).

Abstract: A pilot rest system for use in a flight deck of an aircraft comprising a sleeping area, which comprises two parts, the first part being the space beneath one or more observer seats and the second part being a seat-free area adjacent to said seats. A curtain is preferably provided to enclose the second part of the sleeping area to ensure privacy and keep the sleep area dark if desired. The rest system can further comprise a mini-lavatory and a mini-galley in the flight deck.

Abstract: This rest compartment is intended for at least one aircraft pilot. The said aircraft has a cockpit behind which there is located a first monument (4) separated from a second monument (6) by an aisle (8). A berth (12) is arranged at least partially above the aisle (8) separating the two monuments. One monument (6) is laid out so that it comprises an access to the berth (12).

Abstract: An apparatus and method for improving the fuel range of an aircraft are provided. The aircraft includes a fuselage with a front windshield, and an external skin providing a top cover for a cockpit of the aircraft. The apparatus includes an aerodynamic fairing secured adjacent the windshield and enclosing the external skin covering the cockpit for a reduction in an abrupt change in area encountered by air flowing along the length of the fuselage. An enclosure is formed between the aerodynamic fairing and the external skin in which a fuel bladder, configured with a reticulated polyurethane foam insert, may be disposed for added fuel capacity of the aircraft. The method includes steps of providing an aerodynamic fairing configured to balance the flow of fluid over the aircraft during flight, and securing the aerodynamic fairing atop the aircraft and adjacent the front windshield.

Abstract: An aircraft fuselage barrel (10) includes a skin (12) and a shear tie (18). The shear tie (18) resides within and is integrally formed with the skin (12). The shear tie (18) is separate from and configured for frame attachment thereon. A multi-ring system (79) for fuselage barrel formation includes a mold (68) with a ring (50). The ring (50) has width (W2) approximately equal to a separation distance (D) between two adjacent fuselage frames (22) and includes a module (52) that has a circumferential length (L1) that is greater than a circumferential distance between two fuselage longerons (14). A support structure (80) is coupled to and supports the mold (68). A method of forming the aircraft fuselage barrel (10) includes constructing the support structure (80). Rings (86) of the mold (68) are attached to and over the support structure (80). The mold (68) is constructed. Material is laid-up onto the mold (68) to integrally form the one-piece fuselage barrel (10) including a Hat-configured longeron (14).

Abstract: A pressurized bulkhead or panel for an aircraft includes an energy absorbing skin that deforms in response to an object strike that imparts at least a threshold amount of impact energy to the skin. The skin may be configured as a dome or a lofted panel that is essentially free of rigid stiffeners and non-deformable reinforcement members that would otherwise hinder the flexible characteristics of the skin. The skin may be formed from a monolithic one-piece material, such as metal of composites, and may include various integrally formed reinforcing features.

Abstract: A passenger seat has autonomous electric power generated by a fuel cell system and humidification provided by the fuel cell system. The fuel cell system may include replaceable fuel cartridges and may power electronics such as in flight entertainment, lighting, comfort features, seat adjustments, communications and other features autonomously or under control of the seat occupant.

Abstract: The invention concerns a system for deicing the leading edge of a nose inlet cowl for a turbine engine. The invention is characterized in that one of the two elements formed by the pressurized hot air supply duct (6) and by the protective casing (15) is longitudinally rigid, while the other of said elements comprises at least two mutually nested parts adapted to slide sealingly relative to each other; and said two elements (6, 15) are, on one side, rigidly fixed to one of said partitions (5) of the structure box (10), while, on the other side, said two elements are rigidly linked to each other (in 18) and are adapted to slide jointly relative to a sliding bearing (17) provided in the other partition (16).

Abstract: An aircraft fuel tank assembly comprises a first fuel tank, a second fuel tank and a tank-to-tank overpressure protector therebetween. The overpressure protector has a closed state and an open state. The fuel tank assembly further comprises an indicator for indicating whether the overpressure protector is in the open or closed state, the indication of the indicator being able to be sensed at a location outside of the fuel tanks. The fuel tank assembly may comprise a test mechanism arranged to effect movement of the overpressure valve from the closed state to the open state, the test mechanism being operable from a location outside a fuel tank. The fuel tank assembly may comprise an overpressure valve re-set mechanism, the re-set mechanism being operable from a location outside the fuel tanks.

Abstract: A method of unloading passengers from a vessel is provided, the vessel having passenger resting positions, an exit, and an aisle. The method includes grouping passengers into a plurality of groups including first, second, and third groups, and instructing the first group of passengers to gather their belongings and enter the aisle while the second and third groups to either remain in their passenger resting positions or out of the aisle. The method further includes instructing the passengers in the first group to exit the vessel. Further, the passengers in the second group are instructed to gather their belongings, enter the aisle, and exit the vessel while the third group of passengers remains in their resting position. Further, the third group of passengers is instructed to gather their belongings, enter the aisle, and exit the vessel. These groupings may be based on location of passengers, their travel status, or other suitable criteria.

Abstract: A parachute deployment deceleration assist device for a jumper is disclosed that includes an inverted pocket formed from at least one web of material. The device further includes at least one removable harness attachment means fixed to a peripheral edge of the pocket. Each harness attachment means is selectively attachable to a harness assembly of a parachute between a canopy thereof and the jumper, preferably at a connector link and within easy reach of the jumper when the parachute is fully deployed. In use, before the canopy is inflated the inverted pocket inflates and aids in the deceleration of the jumper, reducing the shock experienced by the jumper upon full inflation of the canopy. Once the canopy is fully inflated and the jumper is falling at a substantially constant speed, the jumper may reach up to remove the device from the harness assembly.

Abstract: A deployment brake release system for use with an airborne guidance unit (AGU) of a parachute suitable for precision cargo delivery. The parachute includes deployment brake lines secured at one end to the edge of the canopy and connected at the other end through looped ends to motor control lines. The motor control lines are, in turn, engaged with the motor of the AGU. The deployment brake release system includes at least one hook mount having a hook secured to the AGU frame. The looped ends of the deployment brake lines are engaged with the hook during rigging so that, upon deployment, opening forces are applied to the hook mount rather than the motor. After full canopy inflation, the motor, via the motor control lines, pulls on the brake line looped ends to disengage them from the hook, transferring subsequent canopy loads to the AGU motor for the remainder of the flight. A method for releasing the deployment brake lines is also disclosed.

Abstract: The invention relates to a piggyback satellite, a device for and a method of attaching piggyback satellites with multiple payloads, including a primary satellite and at least one secondary payload, such as a deployable micro satellite, affixed instrument package or the like, wherein the secondary payload is mounted on the nadir end of the primary satellite, preferably employing a universal adapter between the primary satellite and the at least one secondary payload that releases at least one secondary payload or the like in a certain orbit in space for allowing the secondary payload to continue its journey independently in space for transmitting and receiving data.

Abstract: The invention relates to piggyback secondary payloads, a device for and a method of attaching piggyback secondary payloads, including a primary satellite and at least one secondary payload, such as a deployable microsatellite, affixed instrument package or the like, wherein the secondary payload is mounted on the nadir end of the primary satellite, preferably employing a universal adapter between the primary satellite and the at least one secondary payload.

Abstract: The present invention provides an alternative to the auto-throttle integrated in an aircraft autopilot by restricting the conditions in which the system operates. The proposed system removes the auto-throttle function from the autopilot system and gives it directly to the Full Authority Digital Engine Control (FADEC). A Cruise Control mode is available to the pilot only under stable flight conditions.

Abstract: A method and apparatus for varying the twist of a wing such that induced drag is minimized or reduced during cruise and lift is maximized or increased at least during takeoff and landings. In addition, variations in the twist may produce yawing and rolling moments. The twist amount is varied pursuant to the operating conditions, including those parameters used to determine the lift coefficient. The twist for reducing induced drag and/or improving lift may be employed by geometric or aerodynamic twist, including full span control surfaces used to provide roll control, high-lift and reduced induced drag. The twist may also be employed by twisting just a portion of the wing or the entire wing, either geometrically or aerodynamically.

Abstract: An apparatus for producing vertical lift in a vehicle. In one embodiment, two sets of trans-flow fans discharge air through multi-directional vane assemblies that direct the discharged air outward and downward. Each one of the sets of fans is positioned on opposite sides of the vehicle. The multi-directional vane assemblies include vertical vanes that direct the discharged air fore and aft and horizontal vanes that direct the discharged air downward at various angles. In one embodiment, the vehicle includes a hovercraft skirt and a portion of the discharge air is directed into the skirt, causing the vehicle lift vertically on a cushion of air. In one such embodiment, a flow director controls the amount of discharged air flowing through the inlet to the volume defined by the skirt.

Abstract: An end of train device for an electrically controlled pneumatic brake system includes a radio transceiver, a brake pipe sensor, a brake pipe valve, a manual switch and a first controller controlling the radio transceiver and the valve. It also includes a wire transceiver for wire communication over a train line and a second controller connected to and controlling the wire transceiver. The first and second controllers are connected to each other and control the radio transceiver to be active when the wire transceiver is active. Two batteries are provided with an improved power management circuit to individually charge the batteries.

Abstract: A system for detecting and classifying a wheel of a rail vehicle traveling on a railway track includes a plurality of wheel detectors coupled to one rail of the railway track and configured to detect presence of the wheel and to generate signals representative thereof. A processing system is coupled to the wheel detectors and configured to receive and process the signals. The processing system is configured to classify the wheel based on a speed independent classification value calculated based on the signals from the wheel detectors.

Abstract: One aspect of the present invention relates to a retaining element for securing at least one elongate member to an installation surface in conjunction with a fastener. The retaining element includes a first portion and at least one second portion. The first portion secures the retaining element to the installation surface. The at least one second portion engages the elongate member. Also, the second portion defines a single continuous arch formed by a plurality of engagement surfaces disposed on a bottom side of the second portion. The engagement surfaces define a portion of the perimeter of at least two substantially overlapping shapes, such as ellipses, having different dimensions. In this way, upon installation the elongate member directly engages and is secured to both the installation surface and at least one of the engagement surfaces.

Abstract: A fire hose safety anchor and securement system and method for efficiently and safely retaining multiple fire hoses during pressure testing is provided. The fire hose safety anchor and securement system includes a base member comprised of a base plate and a pair of attached mounting plates interconnected by a pair of retaining brackets and retaining pins. The base member is preferably secured to a floor surface by extending fasteners through a plurality of first anchor apertures. Hoses laid upon the base member are held in place by the retaining brackets. The retaining brackets may be slidably coupled to the base member. The base member may have at least one hose channel with separate retaining brackets for each hose channel allowing at least one hose to be removed from the system while pressure testing of the remaining hoses continues.

Abstract: A bag rack which is configured to support and dispense bags from bag stacks of varying size, wherein a larger size bag pack is positioned to receive a smaller bag pack overlying fashion, the bags positioned so that the smaller bag pack is situated distal the rack and closer to the user, the larger bag pack situated closer to the bag rack, with the smaller pack situated thereupon relative to the user. The rack of the present system comprises contemplates a generally horizontally situated support bar having provided thereon, in slidingly adjustable fashion, support hooks or prongs formed to engage support apertures in the handles of the bags.

Abstract: Described in certain embodiments are mounting systems that employ one or more T-posts to support useful implements such as birdhouses, signs, fencing, banners, and the like. Additional disclosed embodiments relate to unique post- or wall-mount systems for such implements.

Abstract: Aspects of the invention include a support for a rack, such as a sport utility rack that is configured for holding and/or transporting equipment, for instance, bicycles, skis, snowboards, and the like. In certain embodiments, the support is configured for engaging a portion of a sport utility rack, such as those known in the art that include a trailer hitch engagement portion capable of being joined to a trailer hitch receiving element of a vehicle in order to be transported thereby, so as to hold and/or maintain the rack while the rack is not engaged with the vehicle. In certain embodiments, the support is adapted for engaging a trailer hitch engagement portion of a sport utility rack so as to store the rack, while not being engaged with a vehicle, e.g., during transport, and for bearing the weight of the rack while the rack is partially or fully loaded with equipment, such as sports utility equipment (e.g., bicycles).

Abstract: The present invention provides a medical equipment transfer system in which the medical equipment is transferable between alternative support bases. In one aspect of the invention, the system includes first and second support bases and an equipment carriage. The equipment carriage defines a first locking assembly for selectively locking with the first support base and a second locking assembly for selectively locking with the second support base and is simultaneously engageable with the first and second support bases via the first and second locking assemblies. An actuator is operable to simultaneously unlock the equipment carriage from the first support base and lock the equipment carriage to the second support base.

Abstract: A motorized mounting system includes a first portion and a second portion where the first portion is adapted to attach to a mounting surface such as a ceiling or wall, and the second portion is adapted to couple to the back side of a monitor such as a plasma or LCD TV. The second portion has a hinge bracket that attaches to the back side of the monitor. The hinge bracket is mechanically couple to a first motor where activation of the first motor causes the hinge bracket to tilt the monitor. The second portion is mechanically coupled to a second motor where activation of the second motor causes the second portion to swivel relative to the first portion. The motorized mounting system can be controlled by a remote control the tilt and swivel the monitor.

Abstract: A suction device includes a sucking member having a connecting body connected integrally to a flexible disc body that is disposed under an upright sleeve, a connecting member disposed in the sleeve and connected to the connecting body, and an operating rod connected pivotally to a pivot block unit on the sleeve and to the connecting member The operating rod is operable so that an assembly of the connecting member and the connecting body is pulled upwardly, thereby forming a vacant space between a central portion of the disc body and a supporting surface to which a peripheral portion of the disc body is attached sealingly.

Abstract: Described in certain embodiments are mounting systems that employ one or more T-posts to support useful implements such as birdhouses, signs, fencing, banners, and the like. Additional disclosed embodiments relate to unique post- or wall-mount systems for such implements.

Abstract: A wall mount assembly for mounting to a building is described. The wall mount assembly includes a base member having a front surface and a rear surface and having a wall extending about an outer periphery and inwardly from the rear surface. The base member also includes at least one edge recessed rearwardly from the front surface defining a recessed portion therein. The edge of the recessed portion also defines mounting apertures, mounting holes and/or mounting surfaces spaced about the recessed portion. An annular flange extends rearwardly from the recessed portion. An insert member and/or a cover member mount to either one of the mounting apertures, mounting holes and/or mounting surfaces for creating an aesthetic appearance.

Abstract: Disclosed is a simple, inexpensive utility container device for use with a hollow rung ladder. The container device includes a rung insert member and a container for holding a liquid material. The container includes a pair of aligned openings that are offset rearwardly so that the container automatically tips to a suitable forward angle to make it easier for the user to access the contents of the container. In a preferred device, the rung insert member will include a rung insertion portion at each end of the rung insert member, with a container holding portion therebetween, to permit the device to be used in either right or left hand mode. In an alternative embodiment, the rung insert member and container are an integral unit.

Abstract: The present invention provides a moving apparatus capable of efficiently utilizing work space on a desk, and stabilizing an operating load. The present invention includes a placing portion to place a personal computer, a moving portion to move the personal computer from a use position for using the personal computer to a non-use position different from the use position, and a fixing device to detachably fix the moving portion to a desk. The position of the placing portion is determined by the length of an extension mechanism. The positioning operation to determine the length of the extension mechanism is performed by an operating device that transfers the displacement magnitude of an operating portion to an action portion by hydraulic pressure. The operating load is stabilized because the displacement magnitude is transferred by hydraulic pressure.

Abstract: A mount system attaches a monitor to a support base such as a table or wall and is able to reposition the monitor through one or more motorized action. In particular, the mount system includes a motor to tilt the monitor. The mount system includes a mount plate that is adapted to attach to the back side of the monitor. The mount plate may be pivotably coupled to a housing at a first pivot point or axis so that the mount plate may pivot along the first pivot point relative to the housing. A shaft is provided between the mount plate and the housing. The shaft has a proximal end and a distal end. The distal end is pivotably coupled to the mount plate and the proximal end is coupled to a motor, and as the motor is activated, the distal end extends or retracts relative to the housing such that the mount plate extends or retracts relative to the housing.

Abstract: Disclosed herein is a system allowing mechanical coupling and decoupling of an electronic display to a support member. The system includes a first mounting component mountable to the support member, and including a first engaging member. The system further includes a second mounting component supportable from a back of the electronic display, and including a second engaging member having a shape complementary to the first engaging member to permit the second engaging member to matingly engage the first engaging member by sliding the second engaging member onto the first engaging member to support the electronic display on the support member. The first engaging member includes a wedge-shaped member, and the second mounting component includes a plurality of holes for inserting a corresponding plurality of fasteners therethrough.

Abstract: A protective sleeve includes primarily a sleeve which contains an emplacement space for installing an MP3 (digital audio player) and is formed integrally. A back plate at an opening end at a top of the sleeve is extended upward to form an extension piece which is provided with a through-hole, and an enhancement rib is located at a bottom side of the extension piece and is extended downward to a position below the sleeve. A slot hole is located at a bottom surface of the sleeve, a transparent and concaved window area is located at a top plate of the sleeve, and a hollow part is located at a bottom of the window area. Accordingly, the sleeve can achieve a function of protection, and is provided with effects of a stronger structure and better practicability.

Abstract: A device for stowing and deploying a handheld device such as a telecommunications handset within an aircraft or other vehicle has a housing, a pivoting cradle attached to the inner surface of the housing, means for limiting the range of permitted pivoting motion of the cradle within the housing, optional biasing means such as a coil spring between the housing and the pivoting cradle, and means for mounting the housing to a secure place in the aircraft. The cradle has an elongate base with a handset receiving section, and a pivoting mount affixed or integrally molded on each side of the housing. The symmetrical pivoting mount may be a series of at least two slots arrayed in a radius from the geometric pivot point, i.e., the axis of rotation of the handset cradle.

Abstract: One embodiment of an adaptive device for laptop computers and of the type having a heat resistant, slip proof top (10). The durable outer casing (12) is constructed of any material that can be molded to desired shape while maintaining structure integrity. The sides of the outer casing contain a small imprint in the center to ensure that the inside casing (16) retains its form. This inside casing rotates along the ball bearing case (18). In addition, a set of teeth (20) run along the inside casing, which communicate with a lock slide switch (14). Other embodiments are described and shown.

Abstract: A flat display drive apparatus is proposed which is capable of driving a flat display to swivel to the left and right in the horizontal direction. There is provided an drive apparatus for supporting a flat display at the bottom thereof and driving the flat display to swivel to the left and right in the horizontal direction comprising: an electric motor for rotation which is mounted on a base plate for rotation; and a reduction gear train for rotation which serves to reduce the rotation and swivel the flat display to the left and right in the horizontal direction.

Abstract: A device to hold an open book at an open page is disclosed in which the page is clamped between a lip (1, 21) and a resilient book cover support (3, 23). Two embodiments of the device (10, 20) are disclosed, the former being fabricated as a single piece, the latter being able to be folded for compact packaging. In either case pages of the open book can be turned at will.

Abstract: A multi-function portable table includes two cases, which are jointed to each other by hinges and are releasably fixed to each other by at least one releasable buckle mounted therebetween at one lateral side opposite so as to allow the cases to be expanded in a rotation manner. The cases have opposing surfaces in which cavities are defined. Foldable legs are arranged in the cavities. The cases that are expanded to form a tabletop are supported by the legs that are expanded from inside the cavities of the cases. Further, one of the cases can be converted into an easel, while the other one is provided with storage spaces for articles/objects so as to allow for easy use in outdoor activities.

Abstract: The operation torque during disengaging of clutch projections out of clutch grooves, is effectively suppressed from excessively increasing immediately after start of device assembling. In a door mirror device, a gear plate has clutch grooves made substantially in trapezoidal form, in circumferential cross-section, increasing in width from a groove bottom to an opening end. A clutch disk has clutch projections made substantially in trapezoidal form, in circumferential cross-section, decreasing in width in taper form from a base toward a tip wherein the top surfaces are made in an inverted radial form decreasing in width from inner periphery to outer periphery. Due to this, when a torque exceeding a set value is transmitted to the gear plate, the pressure-contact area of the clutch projection with the clutch groove gradually moves from inner periphery to outer periphery while moving the clutch disk upward against a bias force of a clutch spring.

Abstract: A seat track assembly an illustrative embodiment of the seat track assembly includes a seat track having an elongated track plate and a pair of generally elongated, parallel, spaced-apart track flanges extending from the track plate. Each of the track flanges is variable in depth. A method of fabricating a seat track assembly is also disclosed.

Abstract: The present invention provides a vibration-damping structure for an audio apparatus, accommodating a main transformer, which becomes a vibration source when driven, the vibration-damping structure including: a main chassis to which a signal processing board for processing an audio signal is attached, the first chassis defining a portion of an outer shape of an assembly of the vibration-damping structure; a sub-chassis fastened to an inner surface of the main chassis so as to be partially in contact with the inner surface of the main chassis via a plurality of fastening members; and a component accommodating chassis fastened to an inner surface of the sub-chassis so as to be partially in contact with the inner surface of the sub-chassis via other fastening members, wherein the main transformer is fixed to the component accommodating chassis.

Abstract: A pedestal comprises a body coupled to a product to support the product, a guide part disposed on the body to guide the product to a coupling location between the product and the body, and a drawer disposed in the body. With this construction, the pedestal enables the product such as a washing machine to be firmly secured to the pedestal while allowing easy detachment of the product therefrom.

Abstract: A fan fixing structure for holding a fan and fixing it on a housing is provided. The structure includes a guide piece secured on the housing, a cover plate, a resilient piece and a positioning element. The cover plate is pivoted on the guide piece and pivotedly rotates between an open position and a closed position. When the cover plate is in the open position, it further shifts to an engaged position. Therefore, the fan is moved into the guide piece by the guidance of the guide piece, and then fixed on the housing by pivotedly rotating the cover plate to the closed position and moving it to the engaged position. Meanwhile, the fan is stably located in the engaged position by the proper arrangement of the resilient piece and the positioning element. The object of easily assembling, fixing and disassembling the fan without tools is achieved.

Abstract: A building structure formed of concrete and including dams to form raised structures on the roof and a method of overturning the concrete mold.

Abstract: Methods and devices for generating multiple, closely spaced, independently controlled near-field light sources are disclosed. By providing an aperture having at least two, orthogonally oriented ridge structures, two or more closely spaced near-field light sources can be generated by controlling the polarization direction of the illuminating radiation. Control of the shape of the aperture, and relative dimensions of the ridge structures allows optimization of the relative intensities of the near-field sources.

Abstract: A method and system for adjusting a light source that is capable of displaying light of different colors receives inputs from various sources and provides an output color selection signal. The output color selection signal is applied to the light source to adjust the intensity and color thereof.

Abstract: Disclosed are a peripheral light sensor and a liquid crystal display device using the same. The device includes: a peripheral light sensor including: one or more transistors each coupled between an output line and a ground power sources, and having a gate electrode coupled to the ground power source and a first electrode, a voltage value of the respective ground power source being less than a maximal voltage value supplied to the respective output line, wherein each of the transistors is configured to output to the respective outline line a peripheral light sensing signal corresponding to an intensity of a peripheral light.