1889
What this relationship shows is that the effective elastic modulus can be controlled by the density alone this means that a lattice with unit cell design of 50 % density may use any unit cell size as long as the total space filled contains at least six unit cells in each direction then the material stiffness will be the same .
 machanical property: elastic modulus; material: be; machanical property: density; concept or principle: lattice; concept or principle: unit cell; engineering feature: design; machanical property: density; concept or principle: unit cell; material: as; material: as; concept or principle: unit cells; engineering feature: material stiffness; material: be
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:
 machanical property: elastic modulus; material: be; machanical property: density; concept or principle: lattice; concept or principle: unit cell; engineering feature: design; machanical property: density; concept or principle: unit cell; material: as; material: as; concept or principle: unit cells; engineering feature: material stiffness; material: be