1888
A lattice structure can be approximated as an open-cell foam , with effective elastic modulus E of the lattice related to the density of the structure and the elastic modulus of the bulk material - solid as follows : E = 2 E s o l i d s o l i d 2 In this relationship , the constant depends on the manufacturing accuracy and material properties and varies between 0.1 and 4 but is a constant for a specific material and process .
 engineering feature: lattice structure; material: be; material: as; material: foam; machanical property: elastic modulus; concept or principle: lattice; machanical property: density; concept or principle: structure; machanical property: elastic modulus; material: material; material: as; material: s; material: o; material: s; material: o; manufacturing process: manufacturing; process characterization: accuracy; concept or principle: material properties; material: specific material; concept or principle: process
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: lattice structure; material: be; material: as; material: foam; machanical property: elastic modulus; concept or principle: lattice; machanical property: density; concept or principle: structure; machanical property: elastic modulus; material: material; material: as; material: s; material: o; material: s; material: o; manufacturing process: manufacturing; process characterization: accuracy; concept or principle: material properties; material: specific material; concept or principle: process