Abstract: Methods for converting, encoding, decoding and transcoding an acoustic field, more particularly a first-order Ambisonics three-dimensional acoustic field.

Abstract: Capturing, encoding and transcoding an acoustic field, such as a three-dimensional acoustic field, comprising a device made up of two microphones, directional analysis and encoding means of said acoustic field, and optionally means for transcoding said acoustic field.

Abstract: A tank for removing unabsorbed gas from a mixture of unabsorbed gas and liquid. The tank has an inlet pipe that carries an unabsorbed gas and liquid mixture into the tank. A deflector is located at the exit of the inlet pipe so that when the unabsorbed gas and liquid mixture strikes the deflector there is a rapid reduction of flow velocity of the mixture and a directional change of flow of the mixture. A separation chamber, in the form of a cylinder, extends at one end into a gas pocket and at the other end into the mixture at the bottom of the tank past the deflector so that once the mixture hits the deflector the less dense unabsorbed gas is directed generally upwards. When it reaches the top of the separation chamber the unabsorbed gas passes into the gas pocket. A liquid retention chamber is defined by the wall of a second cylinder and an outlet pipe.

Abstract: A method of preparing liquid nonpolymeric controlled release nitrogen plant food composition by the condensation reaction of about one molecule ammonia, about two molecules of urea, and about three molecules of formaldehyde in base buffered aqueous solution at a minimum pH of 7 and a temperature of about 100.degree. C. and concentrating by evaporation until nitrogen concentration is between 20 and 30 percent before formation of polymers containing more than 3 urea moieties occurs. The new nonpolymeric aqueous liquid controlled release nitrogen plant food composition prepared exhibits high storage stability, low phytotoxicity, high nitrogen availability to plants, and contains less than 6 percent unreacted urea nitrogen, less than 1 percent unreacted ammonia nitrogen, and contains large amounts of 5-methyleneuriedo-2-oxohexahydro-s-triazine.

Abstract: A two stage method for preparing clear, storage stable, controlled release polymethylene urea nitrogen fertilizer solution. In the first stage, urea is reacted with a molar excess of formaldehyde, with temperatures of 75.degree. to 100.degree. C., at near-neutral pHs provided by buffers such as sodium bicarbonate, in the presence of ammonium compounds, until the formaldehyde is substantially converted to methylene moeities. In the second stage, the methylene moeities are reacted with additional urea and ammonium compounds, with temperatures of 75.degree. to 100.degree. C., in a near-neutral buffered solution at a pH of between 6.9 and 8.5, until the added urea is substantially converted to water soluble branched chain polymethylene ureas. Optimum urea to formaldehyde mol ratio in the first stage is between 0.483 and 0.518 to 1 and in the second stage optimum ratio is between 1.3 and 1.5 mols urea per mol of formaldehyde.