1054
Support-free structures with reasonably good quality can generally be expected for an inclination angle in the realm of 45 , which has been widely adopted for structural optimization problems anything lower is associated with additional fabrication cost motivating efforts in achieving conformity between design and print .
 concept or principle: quality; material: be; engineering feature: inclination angle; concept or principle: structural optimization; manufacturing process: fabrication; engineering feature: design; manufacturing process: print
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:
 concept or principle: quality; material: be; engineering feature: inclination angle; concept or principle: structural optimization; manufacturing process: fabrication; engineering feature: design; manufacturing process: print