Abstract: Methods, systems and computer program products for providing personalized education content recommendations are disclosed. A computer-implemented method may include receiving information describing a body of content, receiving data describing an interaction of a user with one or more elements of the body of content, receiving a context that includes one or more criteria associated with the body of content, generating a list of modules from the body of content based on the data describing the interaction of the user with the one or more elements of the body of content in view of the context, and providing the generated list of modules to an interested party.

Abstract: Methods, systems and computer program products for providing personalized educational content recommendations are disclosed. A computer-implemented method may include receiving information describing a body of content, receiving data describing an interaction of a user with one or more elements of the body of content, receiving a context that includes one or more criteria associated with the body of content, generating a list of modules from the body of content based on the data describing the interaction of the user with the one or more elements of the body of content in view of the context, and providing the generated list of modules to an interested party.

Abstract: Systems, methods, and related technologies for generating content relationships based on aggregate user feedback are described. In certain aspects, a plurality of content items can be received, each of the content items being associated with one or more respective metadata items. The plurality of content items and one or more corresponding metadata items can be processed to identify two or more potentially related content items. The two or more potentially related content items can be provided to one or more users. One or more feedback items with respect to the relationship between the two or more potentially related content items can be received from the one or more users. At least one of the two or more potentially related content items can be categorized based on the one or more feedback items.

Abstract: Methods, systems and computer program products for providing personalized educational content recommendations are disclosed. A computer-implemented method may include receiving information describing a body of content, receiving data describing an interaction of a user with one or more elements of the body of content, receiving a context that includes one or more criteria associated with the body of content, generating a list of modules from the body of content based on the data describing the interaction of the user with the one or more elements of the body of content in view of the context, and providing the generated list of modules to an interested party.

Abstract: A frangible bullet for use in training ranges as an alternative to live ammunition, which disintegrates upon impact with a target. The frangible bullet includes an elongated frangible core member fabricated from a thermoplastic polymer and at least one metal, the core member having a back end, an opposite tip end and a central portion therebetween, and having a core length between the back end and the tip end. The core member is jacketed in an outer jacket having a closed first end and an opposite opened second end, having a jacket length between the first end and second end, and defining a jacket chamber for complementarily receiving the core member therein. The core member fits inside the outer jacket such that the tip end of the frangible core member is exposed and impacts the target first, resulting in fragmentation of the core member and the outer jacket.

Abstract: In an energy recovery ventilator (ERV) for exchanging indoor air with outdoor air. The ERV having a housing including first and second input ports, and, first and second exhaust ports, and a heat exchanger core. The ERV further having a first blower for drawing indoor air into the ERV through the first input port, through the heat exchanger core and out the first exhaust port, and a second blower for drawing outdoor air into the ERV, through the second input port, through the heat exchanger core and out the second exhaust port. A means for defrosting the ERV is taught having a first bypass from the first exhaust port to the first input port and second bypass from the second exhaust port to the second input port. Dampers close the first exhaust port and the exhaust port when defrost of the heat exchanger core is needed.

Abstract: An air exchanger for continuously exchanging indoor air with outdoor air to provide a constant supply of fresh air into a structure which includes a heat exchanger having a continuous structure which defines adjacent first and second sets of channels which open toward opposite sides of the air exchanger. The air exchanger draws outdoor air through the first set of channels in a first direction and indoor air through the second set of channels in a second, counter-direction. Heat is transferred between the indoor and outdoor air streams such that when the outdoor air enters the room, its temperature approaches the indoor temperature and indoor heating or cooling effects are minimized.

Abstract: A portable and compact room air purifier having an internal filter element through which air is drawn by a centrifugal fan and wherein the air is discharged generally uniformly and radially by passing between at least one generally arcuate scroll and a surrounding deflector. The purifier is automatically deactivated in the event of destruction or removal of the filter housing.

Abstract: A pressure switch for an energy recovery ventilator. The energy recovery ventilator for exchanging indoor air with outdoor air. The energy recovery ventilator having a housing including a first, and a second input port, and, a first and a second exhaust port, and a heat exchanger core. The energy recovery ventilator further having a first blower for drawing indoor air into said energy recovery ventilator through said first input port, through said heat exchanger core and out said first exhaust port, and a second blower for drawing outdoor air into said energy recovery ventilator through said second input port, through said heat exchanger core and out said second exhaust port. The pressure switch for determines if there is balanced air flow through the energy recovery ventilator. The pressure switch comprises means for sensing the pressure at the heat exchanger core near all four ports.

Abstract: A ceiling mounted air purifier that provides a high velocity, multi-directional air exhaust pattern that distributes filtered air to all areas of a room which includes a plurality of filters and centrifugal fans. The centrifugal fans are substantially surrounded by baffles which form generally equally spaced exhaust outlets.

Abstract: This invention relates generally to ornamental lighting controls and particularly to a lighting control for Christmas tree lighting having preferably at least four duty cycle outputs and wherein the duty cycle pattern of each output differs, with respect to a predetermined time interval, from the duty cycle pattern of each of the other outputs of the control thereby to produce, in a plurality of ornamental lighting strings respectively connected to the outputs of the control, a coordinated condition of continuously changing light intensities between strings that occur in predetermined sequential time differing order to result in an overall lighting effect totally unobtainable by any other form of light controlling apparatus.The present device is an improvement over applicant's U.S. Pat. Nos.

Abstract: Portable room air purifiers having replaceable and generally cylindrical high efficiency particulate air filters which are mounted to receive incoming air which is drawn therethrough by centrifugal fans positioned adjacent deflectors in such a manner that air is directed radially outwardly through generally annular exhaust openings in a quiet and yet highly efficient manner. The fans, air deflectors and exhaust openings are designed to create outlet air flow patterns which will give a positive physical indication that the air filters should be replaced. In one embodiment of the invention, the filter units are stackable so as to permit increased air flow rates without modifying the centrifugal fan or fan motor.

Abstract: Compact centrifugal fan and filter assemblies for use in providing laminar flow clean air to a work space environment such as those within clean rooms and clean air work stations or cabinets wherein the fan and filter element are mounted in a close physical relationship with respect to one another and within a common plenum chamber and wherein the fan creates an airflow which is initially generally parallel with respect to the filter element and which is thereafter channeled by baffle members so as to provide uniform air pressure and airflow across the filter element while reducing vibration and increasing the air flow rate from the fan and filter assemblies to such clean air environments.

Abstract: A hand-held pneumatic caulking gun wherein self-contained pneumatic pressure is continuously applied to the caulk driving piston of the gun while the piston is held against movement by this pressure until manually released by a piston movement controlling trigger. The gun further includes a breaking system whereby the rate of movement of the piston, after its release by the trigger, may be selectively regulated. The gun provides that the pneumatic pressure operative to drive the piston forward and toward its caulk driving position may be redirected as required to return the piston to its retracted or initial position. Additionally is included apparatus for manually driving the piston backwards against its driving pressure as required to release piston pressure upon the caulking being dispensed.

Abstract: A hand-held electric caulking gun wherein a caulk-driving piston is forced through the caulk-retaining receptacle of the gun in a manner to force caulking from the gun with considerable force and at a continuous easy-to-control flow. The gun includes a spring type clutch linkage that operates to yieldably disengage the drive source from the piston should the reacting force against the caulk driving end of the piston exceed a predetermined value and a releasing device for allowing the piston to be disengaged of its drive linkage for allowing manual movement of the piston through the gun.

Abstract: An apparatus for providing a prefabricated knockdown clean room which may be readily assembled without tools in a minimum of time. The apparatus includes a plurality of building segments which cooperate with each other in assembled relationship and certain of such segments include means for moving air under pressure through a filter media which removes substantially all micro-organisms from the air within the apparatus to supply Class 100 air to a restricted area.

Abstract: A hand-held electric caulking gun wherein a caulking-driving piston is forced through the caulk-retaining receptacle of the gun in a manner to force caulking from the gun with considerable force and at a continuous easy-to-control flow. The gun includes a spring type clutch linkage between the motor and piston that operates to yieldably disengage the drive source from the piston should the reacting force against the caulk driving end of the piston exceed a predetermined value and a releasing device for allowing the piston to be disengaged of its drive linkage for allowing manual movement of the piston in either direction through the gun.

Abstract: A resistance disk that is so constructed that as the disk is rotated between a pair of fixed contact members, there is produced between the contacts a varying and random like resistance pattern of a character unobtainable with any other form of resistance apparatus and further including the feature whereby the varying resistance pattern may be selectively altered by radial movement of one of the contact members across the face of the disk.

Abstract: A hand held electric caulking gun wherein a caulk-driving piston is forced through the caulk-retaining receptacle of the gun in a manner to force caulking from the gun with considerable force and at a continuous easy-to-control flow. The gun includes a clutch for drivably interrupting movement between the drive source and piston should the reacting force against the caulk driving end of the piston exceed a predetermined value and a piston release structure for allowing the piston to be disengaged of its drive linkage for allowing manual movement of the piston through the gun.