Context and question: Botany was greatly stimulated by the appearance of the first "modern" text book, Matthias Schleiden's Grundzüge der Wissenschaftlichen Botanik, published in English in 1849 as Principles of Scientific Botany. Schleiden was a microscopist and an early plant anatomist who co-founded the cell theory with Theodor Schwann and Rudolf Virchow and was among the first to grasp the significance of the cell nucleus that had been described by Robert Brown in 1831. In 1855, Adolf Fick formulated Fick's laws that enabled the calculation of the rates of molecular diffusion in biological systems.
What theory did Schleiden co-found?
Answer: cell theory
Context and question: A number of technologies allow asphalt/bitumen to be mixed at much lower temperatures. These involve mixing with petroleum solvents to form "cutbacks" with reduced melting point, or mixtures with water to turn the asphalt/bitumen into an emulsion. Asphalt emulsions contain up to 70% asphalt/bitumen and typically less than 1.5% chemical additives. There are two main types of emulsions with different affinity for aggregates, cationic and anionic. Asphalt emulsions are used in a wide variety of applications. Chipseal involves spraying the road surface with asphalt emulsion followed by a layer of crushed rock, gravel or crushed slag. Slurry seal involves the creation of a mixture of asphalt emulsion and fine crushed aggregate that is spread on the surface of a road. Cold-mixed asphalt can also be made from asphalt emulsion to create pavements similar to hot-mixed asphalt, several inches in depth and asphalt emulsions are also blended into recycled hot-mix asphalt to create low-cost pavements.
What are some bitumen emulsions blended with to make a low-cost product?
Answer: recycled
Context and question: Reverse osmosis (R/O) desalination units supplement rainwater harvesting on Funafuti. The 65 m3 desalination plant operates at a real production level of around 40 m3 per day. R/O water is only intended to be produced when storage falls below 30%, however demand to replenish household storage supplies with tanker-delivered water means that the R/O desalination units are continually operating. Water is delivered at a cost of A$3.50 per m3. Cost of production and delivery has been estimated at A$6 per m3, with the difference subsidised by the government.
What type of desalination is used on Funafuti?
Answer:
Reverse osmosis