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A good example of topology optimization , applied to an extreme lightweighting requirement is the design of a titanium alloy drone frame , with larger dimensions than can be produced on typical powder bed fusion systems .
 engineering feature: topology optimization; machanical property: lightweighting; engineering feature: design; material: titanium alloy; engineering feature: dimensions; material: be; manufacturing process: powder bed fusion
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 engineering feature: topology optimization; machanical property: lightweighting; engineering feature: design; material: titanium alloy; engineering feature: dimensions; material: be; manufacturing process: powder bed fusion