Abstract: A plant grow tray system comprising a plurality of trays comprising at least one upper tray and at least one bottom tray is provided. The upper tray is placed inside the bottom tray with upper tray supports between the upper tray and the bottom tray creating a space between the trays. The upper tray and the bottom tray comprise a sealing mechanism to seal the upper tray to the bottom tray. The upper tray has a corrugated profile with crest and trough portions, air holes on the corrugated surface, a drain basin, drain flange, and drain pipe. The bottom tray has an air-flow modifier, air flange, and a drain hole. The system is designed to allow air to be ducted or exhausted from the space between the upper tray and the bottom tray enabling the delivery of conditioned, fresh, or recirculated air directly to a plant.

Abstract: A plant grow tray system comprising a plurality of trays comprising at least one upper tray and at least one bottom tray is provided. The upper tray is placed inside the bottom tray with upper tray supports between the upper tray and the bottom tray creating a space between the trays. The upper tray and the bottom tray comprise a sealing mechanism to seal the upper tray to the bottom tray. The upper tray has a corrugated profile with crest and trough portions, air holes on the corrugated surface, a drain basin, drain flange, and drain pipe. The bottom tray has an air-flow modifier, air flange, and a drain hole. The system is designed to allow air to be ducted or exhausted from the space between the upper tray and the bottom tray enabling the delivery of conditioned, fresh, or recirculated air directly to a plant.

Abstract: An instrument for a solar energy system including a receiver and a heliostat to reflect solar energy on to the receiver. The instrument includes a first element adapted to form an image of the sun, a second element adapted to form an image of the receiver, and a detector. The detector is positioned to receive each of the images and a comparator is adapted to detect a distance between the images. The comparator generates an error correction signal based on the distance between the images. The error correction signal is received by a controller that controls the operation of a postioner that adjusts the position of the heliostat accordingly.

Abstract: The invention relates to a process for the preparation of activated chitosans, in which process a chitosan is reacted with an acid for salt formation, preferably followed by a reaction with a base. The addition of acid and the addition of bases which is preferably to be effected in the activation are carried out in a suspending agent which largely prevents the chitosan salts from dissolving, suitable suspending agents can be both aqueous solutions of inorganic salts and organic or aqueous-organic solvents. The invention also relates to a process for the preparation of both water-soluble and water-insoluble chitosan derivatives by reacting the activated chitosans with reagents which are generally suitable for the reaction of polysaccharides or amines.

Abstract: The invention relates to water-soluble cellulose ethers, containing at least one fluorine-free radical attached via an ether link and selected from the group hydroxyethyl, hydroxypropyl, methyl, ethyl and carboxymethyl, and a hydrophobic substituent which comprises one fluorine-containing alkyl radical of 3 to 24, in particular 5 to 18, carbon atoms, the fluorine content being 0.05 to 5, in particular 0.1 to 1% by weight, based on the dry weight of the cellulose ether.