Classification
ENA - Energy from biomass and waste
29
EHA - Renewable energy sources
13
EXA - Energy policy
9
LTN - Biotechnology - biodegradation
9
EIA - Solar energy - general
5
CXRU - Synthetic fuels
4
EAE - Energy - general
2
EBA - Energy production, energy technology
2
ESA - Synthetic fuels - utilization
2
ETC - Energy conversion
2
LTE - Biotechnology - general aspects
2
LTX - Bioeconomy
2
TKJ - Traffic
2
CEL - Organic synthesis and reactions - general aspects
1
CLMH - Catalytic processes of organic compounds
1
CMDS - Photochemical processes in nature and technology
1
CWE - Chemical engineering, chemical industry - general
1
CXX - Hydrogen production - chemistry and technology
1
EFA - Petroleum, natural gas
1
EIC - Solar thermal energy conversion
1
EIE - Solar equipment
1
ESB - Hydrogen energy
1
ETF - Fuel cells - general
1
ETFG - Polymer electrolyte membrane fuel cells ( PEMFC )
1
FMXG - Metal hydrogen systems - specific aspects, specific systems
1
LEL - Botany - lower plants
1
LTO - Biotechnology - application, industry
1
UKA - Environmental damage and energy production
1
UKH - Environment and power plants, industrial plants
1
USDE - Domestic waste, plastics, paper
1
USDR - Special solid waste
1