Abstract: A two-piece chair and furniture set for allowing the user to easily and quickly assembly and take apart the chairs and table assembly. The two-piece chair and furniture set includes chairs each having a backrest assembly including a backrest portion and a front legs portion; and also includes a seat assembly including a seat portion and a rear legs portion and being detachably attached to the backrest assembly; and further includes a table assembly including a base assembly and also including a tabletop assembly being mounted upon the base assembly.

Abstract: An instrument is provided for measuring the temperature of an object from infrared radiation emitted by the object. The instrument includes a radiation detector, a temperature indicating device connected to the detector, and a modulator disposed in a path of a radiation beam from the object for converting the beam into a series of pulses when the modulator is vibrated in and out of the path. The modulator includes a primary piezoelectric element adapted to vibrate when subjected to driving signals at a frequency related to the resonant frequency of the modulator, and a secondary piezoelectric element connected with and driven by the primary piezoelectric element. The secondary piezoelectric element is electrically insulated from the primary piezoelectric element. The modulator also includes a blocking element connected with the secondary piezoelectric element and disposed to move in and out of the path of the beam.

Abstract: A method and apparatus are described for measuring the amplitude of radiation emitted by an object and compensating for the effects of ambient temperature fluctuations. A radiation sensor is provided receiving radiation from the object and converting it into an alternating current sensor output signal. A thermal sensor detects an ambient temperature proximately to the radiation sensor and generates an alternating current compensation signal having an amplitude proportional to the ambient temperature. A summing amplifier coupled to the radiation sensor and the thermal sensor combines the sensor output signal from the radiation sensor and the compensation signal from said thermal sensor to form an alternating current output signal. The amplitude of the alternating current output signal is proportional to the amplitude of radiation emitted by the object and excludes the effect on the instrument by the ambient temperature.

Abstract: An instrument is provided for measuring the temperature of an object from infrared radiation emitted by the object. The instrument includes a radiation detector, a temperature indicating device connected to the detector, and a modulator disposed in a path of a radiation beam from the object for converting the beam into a series of pulses when the modulator is vibrated in and out of the path. The modulator includes a primary piezoelectric element adapted to vibrate when subjected to driving signals at a frequency related to the resonant frequency of the modulator, and a secondary piezoelectric element connected with and driven by the primary piezoelectric element. The secondary piezoelectric element is electrically insulated from the primary piezoelectric element. The modulator also includes a blocking element connected with the secondary piezoelectric element and disposed to move in and out of the path of the beam.

Abstract: An instrument is provided for measuring the temperature of an object from infrared radiation emitted by the object. The instrument includes a radiation detector, a temperature indicating device connected to the detector, and a modulator disposed in a path of a radiation beam from the object for converting the beam into a series of pulses when the modulator is vibrated in and out of the path. The modulator includes a primary piezoelectric element adapted to vibrate when subjected to driving signals at a frequency related to the resonant frequency of the modulator, and a secondary piezoelectric element connected with and driven by the primary piezoelectric element. The secondary piezoelectric element is electrically insulated from the primary piezoelectric element. The modulator also includes a blocking element connected with the secondary piezoelectric element and disposed to move in and out of the path of the beam.

Abstract: A selective infrared radiation source includes an opaque body of boron nitride positioned to surround a resistive element capable of being heated by the passage of electrical current therethrough, said boron nitride body and resistive element being enclosed by an outer hermetic envelope transparent to infrared radiation. The method includes heating said resistive element such that the boron nitride is heated to a temperature of between approximately 1200.degree. C. and 2000.degree. C.

Abstract: An alkali metal corrosion resistant vacuum tight metal-to-ceramic seal is formed between a high alumina ceramic body and a refractory alkali metal resistant metal member, such as Cb-1Zr, by interposing a powdered brazing mixture comprising by weight a majority of elemental columbium powder and a second metal powder selected from the class consisting of iron and nickel, and firing the assembly in vacuum at a temperature between 1500.degree.C and 1675.degree.C to partially melt a portion of the powder to form a melted bonding phase component interstitially of the undissolved columbium particles for bonding the ceramic to the metal part.