Arthur Casagrande (August 28, 1902 – September 6, 1981) was an Austrian-born American civil engineer who made important contributions to the fields of engineering geology and geotechnical engineering during its infancy. Renowned for his ingenious designs of soil testing apparatus and fundamental research on and soil liquefaction, he is also credited for developing the soil mechanics teaching programme at Harvard University during the early 1930s that has since been modelled in many universities around th..
The monarch butterfly or simply monarch ( Danaus plexippus) is a milkweed butterfly (subfamily Danainae) in the family Nymphalidae. Other common names depending on region include milkweed, common tiger, wanderer, and black veined brown. It may be the most familiar North American butterfly, and is considered an iconic pollinator species. Its wings feature an easily recognizable black, orange, and white pattern, with a wingspan of The viceroy butterfly is similar in color and pattern, but is markedly ..
