1 Subjects: “...gas emission...”

2 Subjects: “...compressed natural gas (CNG)...”

3 Subjects: “...natural gas pipelines...”

4 Subjects: “...gas-liquid mass transfer...”

5 Subjects: “...greenhouse gas emissions...”

6 Subjects: “...greenhouse gas...”

7 Subjects: “...gas-solid separation...”

8 Subjects: “...gas chromatography-mass spectrometry...”

9 Subjects: “...coal containing gas...”

10 Subjects: “...gas chromatography...”