Use python programming to count all unique words for all files in a given directory. the output must be words and their corresponding frequency. note: • to get all files under a directory, use os. listdir(directory name) • to check if a character is an alpha character, you can use the following example expression (3 is not a word character): o > > > str = "hello3hello" o > > > str = str. lower() # to be all lowercase first o > > > str[5] > ‘a’ and str[5] < ‘z’ o > > > false • to debug your code, create a folder with at least 3 text files. you don’t need to submit your example folder and text files.

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

Different types of steels contain different elements that alter the characteristics of the steel. for each of the following elements, explain what the element does when alloyed with steel.

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?