Abstract: A modular shelter pod and system are described herein. In one example, a pod may be formed by a number of foldable or detachable panels, where a first panel includes at least four cavities at first locations having a first shape and a first cross section. A second panel may include at least four tabs at second locations corresponding to the first locations, and having a second shape and a second cross section that fits into and engages the at least four first cavities, such that the at least four tabs engage the at least four cavities to resist movement between different pods when arranged vertically. The pod may additionally include a third panel removably connecting the first panel and the second panel and forming an opening defining a cleaning port that is sealable, where the cleaning port is shaped to removably engage a cleaning device.

Abstract: An electroacoustic transducer for generating an audible acoustic signal includes a base, a cathode having a plurality of cathode discharge elements arranged into an array of cathode discharge elements disposed around an axis associated with the cathode and mounted on the base, and an anode having a plurality of anode discharge elements arranged into an array of anode discharge elements disposed around an axis associated with the anode and mounted on the base. An inter-electrode space separates the cathode and the anode. A first circuit portion connects the cathode to a voltage source, and a second circuit portion connects the anode to the voltage source. The cathode and anode discharge elements extend from the base toward the inter-electrode space. Respective arrays of the cathode and anode are opposite of each other with respect to the inter-electrode space and axisymmetric such that the cathode axis is aligned with the anode axis.

Abstract: An electroacoustic transducer comprises a cathode having a plurality of cathode discharge elements in an array disposed around an axis associated with the cathode; an anode having a plurality of anode discharge elements in an array disposed around an axis associated with the anode; an inter-electrode space separating the cathode and the anode; and a current-limiting element configured to limit current supplied to at least one of the cathode or the anode when connected to the voltage source. The cathode discharge elements and anode discharge elements extend toward the inter-electrode space. The respective arrays of the cathode and anode are opposite of each other with respect to the inter-electrode space and are axisymmetric such that the cathode axis is aligned with the anode axis. At least one of the cathode and anode is configured to generate the acoustic signal when connected to a voltage source through the current-limiting element.

Abstract: An electroacoustic transducer may include a cathode having a plurality of discharge elements assembled into one or more axisymmetric arrays and an anode having a plurality of discharge elements assembled into one or more axisymmetric arrays. The cathode and the anode may be separated by an inter-electrode space and respectively connected to a voltage source. The discharge elements of the cathode and anode may be directed into the inter-electrode space. The axisymmetric arrays of the cathode and anode may be mirror symmetrically arranged opposite each other to form electrode pairs, each electrode pair having an axis of symmetry extending through the geometric centers of the axisymmetric arrays in the pair.

Abstract: In an electro-acoustic transducer including a needle electrode and a counter electrode facing the needle electrode and inducing electric discharge between the needle electrode and the counter electrode for electro-acoustic conversion by an RF voltage applied across the needle electrode and the counter electrode, the counter electrode has a cylindrical surface surrounding plasma extending from the needle electrode and has a cutout in a part of the cylindrical surface. This configuration prevents a short circuit between the needle electrode and the counter electrode due to plasma.

Abstract: An electro-acoustic transducer includes a needle electrode, an opposite electrode, a discharge region between the needle electrode and the opposite electrode, a high-frequency oscillating circuit in the discharge region causing a high-frequency discharge and modulating and extracting an audio signal in accordance with a sound wave introduced to the discharge region, or converting the discharge in the discharge region into a sound wave, the discharge being performed in accordance with a high-frequency signal modulated by an audio signal, and an inert gas supply channel that supplies inert gas toward the peripheral surface of the needle electrode. The electro-acoustic transducer includes a needle-electrode cover as a part of the inert gas supply channel. The needle-electrode cover extends beyond the tip of the needle electrode toward the opposite electrode and has a gas flow outlet disposed beyond the tip of the needle electrode toward the opposite electrode.

Abstract: A system for suppressing sound from a flame comprises a detector for detecting a first signal which emanates from the flame. A photo sensor rapidly detects the noise from the flame. The first signal is inverted to produce a second signal. The second signal is applied to the flame for cancelling the sound produced by the flame. Preferably, an electric arc is produced between a cathode positioned in the flame and an anode positioned around the flame. The electric arc is modulated by the second signal.

Abstract: An information transmission method using arc and apparatus thereof are applied to a loudspeaker and the like having the function of illumination. The information transmission method is characterized in that arc current supplied to an arc generating device is modulated by a signal based on information to vibrate arc column so that at least one of audible waves, ultrasonic waves and arc light is employed to transmit the information. Arc having small mechanical inertia is employed as a sound producing device and accordingly can be used as a loudspeaker having a good frequency characteristic and large output. It can be used as a sound producing device having the function of illumination by utilizing strong light emitted from arc column.

Abstract: A narrow directional microphone comprising a microphone unit and an interference tube with one end covering a forward audio terminal of the microphone. The interference tube has a plurality of first openings spaced from one another axially on the tube for providing acoustic resistance. The interference tube has a plurality of second openings spaced circumferentially from the first openings about the interference tube with a diaphragm secured to the interference tube for covering the second openings.