Described herein is a cover for mounting to a door handle (30) comprises two parts (10, 12) configured for mutual locking engagement such that when the parts are brought into mutual locking engagement around a door handle (30) at least a portion of the door handle is substantially enclosed within a cavity (16) formed between the two parts (10, 12). At least a portion of at least one of the parts (10, 12) is coated, impregnated, or otherwise provided with a self-cleaning material. Also described is a push plate device comprising a first plate (72) for fixing to a door; and a second plate (71) configured to releasably attach to said first plate in order to form a composite plate structure (70). The second plate (71) is at least partly coated, impregnated, or otherwise provided with a self-cleaning material so that the composite plate structure (70) presents a self-cleaning external surface.

Described are systems and methods which can be used to indicate the period of time elapsed since the occurrence of a triggering event. More particularly, this application relates to systems and methods which can be used to visually indicate the time period elapsed since an article has been removed from its packaging. The system can include an indicator disposed on or within the article and a trigger disposed within the receptacle and in contact with the indicator. The article may be enclosed within a sealable receptacle of the package. The indicator is responsive to a change in a concentration of the trigger in contact with the indicator. The removal of the article from the receptacle can induce a change in concentration of the trigger in contact with the indicator. The change in the concentration of the trigger can induce a change in color in the indicator. The color change indicates a predetermined period of time has elapsed since the article has been removed from the receptacle. The predetermined period of time is from 30 minutes to 30 days, such as from 1 hour to 30 days.

Described are systems and methods which can be used to indicate the period of time elapsed since the occurrence of a triggering event. More particularly, this application relates to systems and methods which can be used to visually indicate the time period elapsed since an article has been removed from its packaging. The system can include an indicator disposed on or within the article and a trigger disposed within the receptacle and in contact with the indicator. The article may be enclosed within a sealable receptacle of the package. The indicator is responsive to a change in a concentration of the trigger in contact with the indicator. The removal of the article from the receptacle can induce a change in concentration of the trigger in contact with the indicator. The change in the concentration of the trigger can induce a change in color in the indicator. The color change indicates a predetermined period of time has elapsed since the article has been removed from the receptacle. The predetermined period of time is from 30 minutes to 30 days, such as from 1 hour to 30 days.

The present disclosure describes an electrical cable accessory system for covering an electrical cable and/or cable connection. The electrical cable accessory system includes a pre-expanded cable accessory unit and a time-temperature indicator associated with the pre-expanded cable accessory unit. The pre-expanded cable accessory unit includes a pre-expanded cable accessory formed of an elastomeric material and a removable holdout mounted within the elastomeric cable accessory, wherein the holdout is operative to maintain the elastomeric cable accessory in an expanded state and to permit the elastomeric cable accessory to elastically contract when the holdout is removed from the elastomeric cable accessory. The time-temperature indicator is configured to undergo a visible change in appearance in response to a cumulative heat exposure and signal to a viewer when the elastomeric material of the pre-expanded elastomeric cable accessory unit has experienced a threshold cumulative heat exposure. Methods including the same are also described herein.

The present disclosure describes an electrical cable accessory system for covering an electrical cable and/or cable connection. The electrical cable accessory system includes a pre-expanded cable accessory unit and a time-temperature indicator associated with the pre-expanded cable accessory unit. The pre-expanded cable accessory unit includes a pre-expanded cable accessory formed of an elastomeric material and a removable holdout mounted within the elastomeric cable accessory, wherein the holdout is operative to maintain the elastomeric cable accessory in an expanded state and to permit the elastomeric cable accessory to elastically contract when the holdout is removed from the elastomeric cable accessory. The time-temperature indicator is configured to undergo a visible change in appearance in response to a cumulative heat exposure and signal to a viewer when the elastomeric material of the pre-expanded elastomeric cable accessory unit has experienced a threshold cumulative heat exposure. Methods including the same are also described herein.

A welding control apparatus includes a light sensor configured to detect presence and intensity of welding light, a controller configured to count presence, intensity, and elapsed time of welding light, detected by the light sensor, and to determine welding intensity, weld time, resting time, and weld number, a memory configured to store the welding intensity, the weld time, the resting time, and the weld number, determined by the controller, a display configured to display the welding intensity, the weld time, the resting time, and the weld number, stored in the memory, a shutter driver configured to drive a shutter liquid crystal display (LCD) to vary a darkness concentration, and a setting unit configured to receive a setting value and a manipulation command, set by a user, and to transmit the setting value and the manipulation command to the controller.

A welding control apparatus includes a light sensor configured to detect presence and intensity of welding light, a controller configured to count presence, intensity, and elapsed time of welding light, detected by the light sensor, and to determine welding intensity, weld time, resting time, and weld number, a memory configured to store the welding intensity, the weld time, the resting time, and the weld number, determined by the controller, a display configured to display the welding intensity, the weld time, the resting time, and the weld number, stored in the memory, a shutter driver configured to drive a shutter liquid crystal display (LCD) to vary a darkness concentration, and a setting unit configured to receive a setting value and a manipulation command, set by a user, and to transmit the setting value and the manipulation command to the controller.

A method for measuring the delay between N pulses having a duration less than 100 picoseconds comprises the steps: collimated emission of the pulses having the same repetition frequency, emission of a reference pulse having the same repetition frequency capable of producing interference fringes with each of the pulses, for each of the pulses, detection, by a detector, of the coherent sum of this pulse with the reference pulse, this sum producing the interference fringes, the fringes originating from each of the pulses being distinguishable from one another. The reference pulse is emitted with an adjustable delay, and the method further comprises: for each delay, simultaneous measurement for the pulses of N contrasts of the interference fringes, for each of the pulses, a delay value between this pulse and the reference pulse is determined by the delay corresponding to the maximum contrast.

Ultra-short pulse detection. At least some example embodiments are methods including: receiving by an antenna a series of ultra-short pulses of electromagnetic energy at a repetition frequency, the receiving creates a pulse signal; self-mixing or intermodulating the pulse signal by applying the pulse signal to a non-linear electrical device, thereby creating a modulated signal; and filtering the modulated signal to recover a filtered signal having an intermodulated frequency being the repetition frequency.

A method for measuring the delay between N pulses having a duration less than 100 picoseconds comprises the steps: collimated emission of the pulses having the same repetition frequency, emission of a reference pulse having the same repetition frequency capable of producing interference fringes with each of the pulses, for each of the pulses, detection, by a detector, of the coherent sum of this pulse with the reference pulse, this sum producing the interference fringes, the fringes originating from each of the pulses being distinguishable from one another. The reference pulse is emitted with an adjustable delay, and the method further comprises: for each delay, simultaneous measurement for the pulses of N contrasts of the interference fringes, for each of the pulses, a delay value between this pulse and the reference pulse is determined by the delay corresponding to the maximum contrast.