Cellophane is a thin, transparent sheet or tube of regenerated cellulose, which is the chief constituent of the cell walls of plants. It is used in packaging, as a membrane for dialysis, and can be moisture-proofed. Invented in 1908, cellophane is made by dissolving cellulose alkali, aging it, then regenerating it by forcing it through a slit into a dilute acid solution where it precipitates. Cellophane sales have dwindled because of the presence of what pollutant in its production process? Discuss
Month: June 2023
windsock
Six-Day War Begins (1967)
After a period of relative calm, border incidents between Israel and Syria, Egypt, and Jordan increased during the early 1960s. Palestinian guerrilla attacks on Israel from bases in Syria led to increased hostility between the two countries. After Egypt signed a defense treaty with Jordan, Israel launched a preemptive air strike against the three Arab states, capturing the Sinai Peninsula, Gaza Strip, West Bank, Old City of Jerusalem, and the Golan Heights. How many were killed in the fighting? Discuss
World Environment Day
The United Nations General Assembly designated June 5 as World Environment Day in 1972. The date was chosen because it marked the opening day of the United Nations Conference on the Human Environment, which led to the establishment of the United Nations Environment Programme. The General Assembly urges countries and organizations to mark this day with activities that educate people about threats to the environment and encourage them to strike a balance between development and concern for Earth’s future. Discuss
Federico García Lorca (1898)
García Lorca was a Spanish poet, dramatist, and member of the Generation of ’27, an influential group of poets that arose in Spanish literary circles in the 1920s. His most famous works include the book Gypsy Ballads and his poem, “Lament for the Death of a Bullfighter.” The poetry, passion, and violence of his works, which combine Spanish folklore with his personal experience, and his own tragic and bloody death brought him enduring international acclaim. How did he die? Discuss
go out with the girls
To go and socialize somewhere with a group of exclusively female friends. Watch the video
Clogs
Clogs are shoes or sandals that are made entirely of wood or have wooden soles and leather uppers. They are associated with the Netherlands and Sweden, where they are considered part of the national dress. In England, clogs were traditionally made of alder and were commonly worn by all classes throughout the 18th and 19th centuries. The Lancashire cotton mill workers habitually wore clogs to avoid slipping on the wet floors in the cotton mills. How are clogs used in some styles of dance? Discuss
raring
First Pulitzer Prizes Awarded (1917)
The Pulitzer Prizes—prestigious awards presented annually by Columbia University for achievements in American journalism, literature, and music—were created by journalist and publisher Joseph Pulitzer, whose will funded the establishment of Columbia’s school of journalism as well as the prizes. Ironically, Columbia had rejected donation offers from Pulitzer during his lifetime because, as one of the originators of yellow journalism, he was regarded as unscrupulous. What do prizewinners receive? Discuss
Heinrich Wieland (1877)
Wieland was a German chemist who received the Nobel Prize in Chemistry in 1927 for determining the molecular structure of bile acids, which are produced by the liver. His work provided insight into the mechanism by which bile acids aid in the resorption of food in the intestines and led to the establishment of the close relationship between cholesterol and the bile acids. How did Wieland help students who were persecuted under the Nuremberg Laws of Nazi Germany? Discuss