Enzyme conversion of lignocellulosic plant materials for resource recovery in a Controlled Ecological Life Support System.

A large amount of inedible plant material composed primarily of the carbohydrate materials cellulose, hemicellulose, and lignin is generated as a result of plant growth in a Controlled Ecological Life-Support System (CELSS). Cellulose is a linear homopolymer of glucose, which when properly processed will yield glucose, a valuable sugar because it can be added directly to human diets. Hemicellulose is a heteropolymer of hexoses and pentoses that can be treated to give a sugar mixture that is potentially a valuable fermentable carbon source. Such fermentations yield desirable supplements to the edible products from hydroponically-grown plants such as rapeseed, soybean, cowpea, or rice. Lignin is a three-dimensionally branched aromatic polymer, composed of phenyl propane units, which is susceptible to bioconversion through the growth of the white rot fungus, Pluerotus ostreatus. Processing conditions, that include both a hot water pretreatment and fungal growth and that lead to the facile conversion of plant polysaccharides to glucose, are presented.     

Lens-Effect Loss for Distributed Targets

The atmosphere, acting like a lens, causes a small loss in radarsignal strength [1]. Unlike atmospheric absorption [2], the lenseffect loss is different for distributed targets versus point targets.For a distributed target uniformly filling the radar beam, the lens effect loss (in decibels) is one-half the lens-effect loss for point targets.     

Atmospheric Lens Effect; Another Loss for the Radar Range Equation

A small additional loss for radar range calculations at low grazing angles is described. This loss results because the variation in atmospheric refraction versus altitude makes the atmosphere act like a lens, causing thinning of radar signal energy to and from the target, independent of frequency. The magnitude of loss is derived and is plotted versus grazing angle and range. The maximum two-way loss, occurring at zero degrees grazing angle and a range well beyond the atmosphere, is 2.9 dB.