Answer:
a) D = 4.88 * 10^(-14) m^2 / s
b) <em>t </em>= 1.1 hr
Solution:
a) Magnesium in Aluminum diffusion:
D = Do * exp(-Qd / RT)
= (1.2 * 10^(-4) m^2 / s) * exp ( - 130,000 / 8.31 * 723.15)
= 4.88 * 10^(-14) m^2 / s
D = 4.88 * 10^(-14) m^2 / s
b) The composition remains same at say the distance Xo:
(Cx - Co) / (Cs - Co) = Constant
Xo^2 / D_{550} * <em>t </em>= Xo^2 / D_{450} * 15
D_{550} * <em>t </em>= D_{450} * 15
(1.2 * 10^(-4) m^2 / s) * exp ( - 130,000 / 8.31 * 723.15) * <em>t</em>
(4.88 * 10^(-14) m^2 / s) * 15
by, solving for <em>t </em>we get:
<em>t </em>= 1.1 hr
So, the time required is 1.1 hr.
Answer:
To save the course object instances in an array, use;
Course[] courses = new Course[7];
courses[0] = new Course("IT 145");
courses[1] = new Course("IT 200");
courses[2] = new Course("IT 201");
courses[3] = new Course("IT 270");
courses[4] = new Course("IT 315");
courses[5] = new Course("IT 328");
courses[6] = new Course("IT 330");
Explanation:
The java statement above assigns an array of size 7 with the course class constructor, then order courses are assigned to the respective indexes of the new array.
Answer:
Database Management System.
Explanation:
Database Management System is the collection of programs and data used to create ,define and manipulate the database.
There are several database management systems present and some of them are as following:-
- RDBMS (Relational Database Management System)
- No SQL DBMS
- CDBMS(Columnar Database Management System).
- IMDBMS(In-Memory Database Management System).
Answer:
c. Dark Web
Explanation:
Surface web is also called visible web is a part of world wide web that can be easily searchable using search engines as its contents are indexed by the search engines such as Google and its contents are accessible by public using standard web browsers. So a is not a suitable choice.
Deep Web is called invisible web as it is not accessible or searchable to standard search engines like Google. Search engines cannot index the contents of these sites. However such sites do not requires specialized browsers to access. So b is not a suitable choice.
Dark Web: It is a part of Deep Web sites but it requires specialized software and browsers to access. These sites cannot be indexed and cannot be searchable through standard search engines. This is also called dark side of the world wide web darker which is frequently used by criminals, hackers, black markets, hit-men. Illegal activities on a massive level is takes place in the dark web such as access to stolen sensitive information, malware, drug trade and terrorist operations. These sites are temporary and keep changing addresses to lessen the risk of getting caught by govt agencies or security officials. So c is the suitable choice.
Crypto-Net is a kind of neural network which works with encrypted data which can make a prediction based on the data without disclosing the data and prediction to the 3rd party. So d is not a suitable option.
