Casting (metalworking)

In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods.

Casting processes have been known for thousands of years, and widely used for sculpture, especially in bronze, jewellery in precious metals, and weapons and tools. Traditional techniques include lost-wax casting, plaster mold casting and sand casting.

The modern casting process is subdivided into two main categories: expendable and non-expendable casting. It is further broken down by the mold material, such as sand or metal, and pouring method, such as gravity, vacuum, or low pressure.

Expendable mold casting

Expendable mold casting is a generic classification that includes sand, plastic, shell, plaster, and investment (lost-wax technique) moldings. This method of mold casting involves the use of temporary, non-reusable molds.

Yield

Yield may refer to:

Measures of output/function

Computer science

Yield in programming context simply means "brings". It is usually used when some kind of execution context surrenders control flow to a different execution context. In some cases, upon surrendering control, the first execution context may send (i.e., yield) a data value to the second execution context. See Generator (computer programming).

Physics/chemistry

Earth science

Production/manufacturing

Yield (chemistry)

In chemistry, yield, also referred to as reaction yield, is the amount of product obtained in a chemical reaction. The absolute yield can be given as the weight in grams or in moles (molar yield). The percentage yield (or fractional yield or relative yield), which serves to measure the effectiveness of a synthetic procedure, is calculated by dividing the amount of the desired product obtained by the theoretical yield (the unit of measure for both must be the same):

The theoretical yield is the amount predicted by a stoichiometric calculation based on the number of moles of all reactants present. This calculation assumes that only one reaction occurs and that the limiting reactant reacts completely. However the actual yield is very often smaller (the percent yield is less than 100%) for several reasons:

Yield (college admissions)

Yield in college admissions is the percent of students who choose to enroll in a particular college or university after having been offered admission. It is calculated by dividing the number of students(#) who choose to enroll at a school, which is often based on their decision to pay a deposit, by the number of offers of acceptance and multiplying by one hundred. A higher yield indicates greater interest in enrolling at a particular school of higher education. The yield rate is usually calculated once per year based on admissions statistics. As a statistical measure, it has been used by college ratings services as a measure of selectivity, such that a higher yield rate is a sign of a more selective college. For example, the yield rate for Harvard University was 76% in 2010, while the yield rate for Dartmouth was 55%, and the yield rate for Colorado College was 37%. The yield rate has been sometimes criticized for being subject to manipulation by college admissions staffs; in 2001, a report in the Wall Street Journal by reporter Daniel Golden suggested that some college admissions departments reject or wait list well-qualified applicants on the assumption that they will not enroll, as a way to boost the college's overall yield rate; according to the report, these actions are part of an effort to improve a college's scores on the US News college ranking.