Abstract: A light transmissive insulation system comprising a plurality of layers of light transmissive insulating material, the material beig characterized by transmissivity to solar spectrum radiation, and low transmissivity to thermal radiation. A solar pond employing the insulation system is also described.

Abstract: The invention relates to a method of preparing a biologically high-grade natural food concentrate, characterized by mixing honey or honey mixed with other bee products, a high-grade protein product or a mixture of high-grade protein products, mineral substances and possibly roughage substances and/or carbohydrates with each other in such a manner as to obtain at least 40 wt % honey, referred to the final product, in the final product obtained.The invention also provides a method of producing a biologically high-grade natural food concentrate, characterized by admixing honey or honey mixed with other bee products, a high-grade protein product or a mixture of high-grade protein products, a vegetable fat product or a mixture of vegetable fat products, and possibly mineral additions with each other in such a manner that at least 40 wt % honey referred to the final product, is contained in the resultant final product.