E. Short stack testing
E.2 Ammonia experiments
The ammonia was introduced to the fuel gas mixture from a premixed bottle containing 5000 ppm NH3 in hydrogen. A valve was used to switch between the bottle containing pure hydrogen and that of the ammonia mixture while maintaining constant gain on the mass ow controller. Thus, when switching over to the ammonia/hydrogen mixture, there was approximately 5000 ppm less pure hydrogen in the fuel gas. However, since each ammonia molecule contains 1.5 H2, there was slightly more hydrogen available if the ammonia was cracked to H2 and N2 in the SOFC anode.
The ammonia concentration in the mixed fuel gas was, by referring to Table (E.1), around 2600 ppm since the 5000 ppm ammonia/hydrogen mixture was diluted by CO2, H2O and N2.
E.2.1 Experiments at 900oC
The ammonia experiments at 900oC were carried out after the H2S experiments at that temperature. Two series with around 2600 ppm NH3 were carried out. Before and after each series the stack was operated without ammonia for a while for reference.
It can be seen in Figure (E.5) that for the three series in the middle, i.e. two with ammonia and one without, there does not seem to be any signicant dierence in per-formance of the single cell. The two series with no ammonia before and after the three middle series show a somewhat diverging performance. The reason for this divergence is not clear, but does not necessarily have anything to do with the introduction of am-monia. It is therefore concluded here that the addition of up to around 3000 ppm NH3
does not cause a signicant change on SOFC performance. This is in accordance with the work of Wojcik et al. [106].
E.2.2 Experiments at 800oC
After the ammonia experiments at 900oC, the stack temperature was decreased to 800oC.
A similar series as that performed at 900oC was carried out thereafter, i.e. two series with an ammonia concentration of around 2600 ppm with 0 ppm reference tests before and after each series. The IV-curves of the single cell investigated are shown in Figure (E.6).
Also in these tests there are no signicant performance variations when switching from 0 to 2600 ppm NH3. The very rst and last series, both at 0 ppm NH3 are again a bit diverging. Compared to the experiments at 900oC, however, there does not seem to be any systematised trend behind this.
Again, it is concluded that there does not seem to be any eect on the SOFC perfor-mance as around 2600 ppm NH3 is introduced to the fuel gas.
Short stack testing 155
3 concentrations at 900oC 0 ppm NH
Fig. E.5: Single cell performance at 900oC with varying NH3concentrations; the cell is mounted in a 4-cell stack.
3 concentrations at 800oC 0 ppm NH
Fig. E.6: Single cell performance at 800oC with varying NH3concentrations; the cell is mounted in a 4-cell stack.
156 Short stack testing
BIBLIOGRAPHY
[1] K. Maniatis (2000) Progress in biomass gasication: an overview, European Comis-sion, Brussels, Progress in Thermochemical Biomass ConverComis-sion, Blackwell Science Ltd., UK
[2] H. Hofbauer, G. Veronik, T. Fleck, R. Rauch, H. Mackinger & E. Fercher (1997) The FICFB-gasication process, Developments in Thermochemical Biomass Conversion 2, 1016-1025
[3] H. Risnes (2002) High temperature ltration in biomass combustion and gasication processes, Ph.D. thesis, Norwegian University of Science and Technology
[4] M. Grønli (1996) A theoretical and experimental study of the thermal degradation of biomass, Ph.D. thesis, Norwegian University of Science and Technology
[5] Ø. Skreiberg (1997) Theoretical and experimental studies on emissions from wood combustion, Ph.D. thesis, Norwegian University of Science and Technology
[6] L. Sørum (2000) Environmental aspects of municipal solid waste combustion, Ph.D.
thesis, Norwegian University of Science and Technology
[7] M. Barrio (2002) Experimental investigation of small-scale gasication of woody bio-mass, Ph.D. thesis, Norwegian University of Science and Technology
[8] M. Fossum (2002) Biomass gasication - Combustion of gas mixtures, Ph.D. thesis, Norwegian University of Science and Technology
[9] S. van Loo & J. Koppejan (eds.) (2002) Handbook of Biomass Combustion and Co-Firing, International Energy Agency
[10] P. McKendry (2002) Energy production from biomass (part1): overview of biomass, Bioresource Technology 83, 37-46
[11] C. Di Blasi (1998) Multi-phase moisture transfer in the high-temperature drying of wood particles, Chemical Engineering Science 53 (2), 353-366
[12] C. Di Blasi, C. Branca, S. Sparano & B. La Mantia (2003) Drying characteris-tics of wood cylinders for conditions pertinent to xed-bed countercurrent gasication, Biomass and Bioenergy 25, 45-58
[13] P.M. Lv, Z.H. Xiong, J. Chang, C.Z. Wu, Y. Chen & J.X. Zhu (2004) An experimen-tal study on biomass air-steam gasication in a uidized bed, Bioresource Technology 95, 95-101
[14] K.W. Ragland, D.J. Aerts & A.J. Baker (1991) Properties of wood for combustion analysis, Bioresource Technology 37, 161-168
158 Bibliography
[15] A. Nordin (1994) Chemical elemental characteristics of biomass fuels, Biomass and Bioenergy 6 (5), 339-347
[16] A. van der Drift, J. van Doorn & J.W. Vermeulen (2001) Ten residual biomass fuels for circulating uidized-bed gasication, Biomass and Bioenergy 20, 45-56
[17] X.T. Li, J.R. Grace, C.J. Lim, A.P. Watkinson, H.P. Chen & J.R. Kim (2004) Biomass gasication in a circulating uidized bed, Biomass and Bioenergy 26, 171-193 [18] A. Faaij, R. van Ree, L. Waldheim, E. Olsson, A. Oudhuis, A. van Wijk, C. Daey-Ouwens & W. Turkenburg (1997) Gasication of biomass wastes and residues for electricity production, Biomass and Bioenergy 12 (6), 387-407
[19] X.L. Yin, C.Z. Wu, S.P. Zheng & Y. Chen (2002) Design and operation of a CFB gasication and power generation system for rice husk, Biomass and Bioenergy 23, 181-187
[20] S. Turn, C. Kinoshita, Z. Zhang, D. Ishimura & J. Zhou (1998) An experimental investigation of hydrogen production from biomass gasication, International Journal of Hydrogen Energy 23 (8), 641-648
[21] P. McKendry (2002) Energy production from biomass (part 2): conversion technolo-gies, Bioresource Technology 83, 47-54
[22] C. Di Blasi & C. Branca (2001) Kinetics of primary product formation from wood pyrolysis, Ind. Eng. Chem. Res 40, 5547-5556
[23] S. Zecevic, E.M. Patton & P. Parhami (2004) Carbon-air fuel cell without a reform-ing process, Carbon 42, 1983-1993
[24] P. McKendry (2002) Energy production from biomass (part 3): gasication tech-nologies, Bioresource Technology 83, 55-63
[25] H. Hofbauer, R. Rauch, K. Bosch, R. Koch & C. Aichernig (2003) Biomass CHP plant Güssing - A success story, in A.V. Bridgewater (ed.), Pyrolysis and Gasication of Biomass and Waste, CPL PRess, Newbury, UK
[26] M. Barrio, M. Fossum & J.E. Hustad (2001)A small-scale stratied downdraft gasi-er coupled to a gas engine for combined heat anyud powgasi-er production, in A.V. Bridg-water (ed.), Progress in Thermochemical Biomass Conversion, Blackwell Science Ltd.
[27] S.C. Bhattacharya, S.S. Hla & H.L. Pham (2001) A study on a multi-stage hybrid gasier-engine system, Biomass and Bioenergy 21, 445-460
[28] A.V. Bridgwater (1995) The technical and economic feasibility of biomass gasica-tion for power generagasica-tion, Fuel 74 (5), 631-653
[29] R.H. Williams & E.D. Larson (1996) Biomass gasier gas turbine power generating technology, Biomass and Bioenergy 10 (2-3), 149-166
[30] P.H. Steinwall (1997) Integration of biomass gasication and evaporative gas turbine cycles, Energy Conversion Management 38 (15-17), 1665-1670
[31] T. Kivisaari, P. Björnbom & C. Sylwan (2002) Studies of biomass fuelled MCFC systems, Journal of Power Sources 104, 115-124
Bibliography 159 [32] M. Kübel, R. Berger & K.R.G. Hein (2002) Biomass gasication: An option for
SOFC Fuel?, Proc. Fifth European Solid Oxide Fuel Cell Forum, vol. 2, 995-1002 [33] T.B. Reed & A. Das (1988) Handbook of biomass downdraft gasier engine systems,
The Biomass Energy Foundation Press, Golden, CO
[34] A.A.C.M. Beenackers (1999) Biomass gasication in moving beds, a review of Eu-ropean technologies, Renewable Energy 16, 1180-1186
[35] J. Larminie & A. Dicks (2000) Fuel Cell Systems Explained, Wiley
[36] N.M. Sammes & R. Boersma (2000) Small-scale fuel cells for residential applications, Journal of Power Sources 86, 98-110
[37] G. Cacciola, V. Antonucci & S. Freni (2001) Technology up date and new strategies on fuel cells, Journal of Power Sources 100, 67-79
[38] G.F. McLean, T. Niet, S. Prince-Richard & N. Djilali (2002) An assessment of alkaline fuel cell technology, International Journal of Hydrogen Energy 27, 507-526 [39] E. Gülzow & M. Schulze (2004) Long-term operation of AFC electrodes with CO2
containing gases, Journal of Power Sources 127, 243-251
[40] K. Kordesh, V. Hacker, J. Gsellmann, M. Cifrain, G. Faleschini, P. Enziger, R.
Fankhauser, M. Ortner, M. Muhr & R.R. Aronson (2000) Alkaline fuel cells applica-tions, Journal of Power Sources 86, 162-165
[41] R. Song & D.R. Shin (2001) Inuence of CO concentration and reactant gas pressure on cell performance in PAFC, International Journal of Hydrogen Energy 26, 1259-1262 [42] K. Matsumoto K & K. Kasahara (1998) Long-term commitment of Japanese gas
utilities to PAFCs and SOFCs, Journal of Power Sources 71, 51-57
[43] J.P.P Huijsmans, G.J. Kraaij, R.C. Makkus, G. Rietveld, E.F. Sitters, H.Th.J.
Reijers (2000) An analysis of endurance issues for MCFC, Journal of Power Sources 86, 117-121
[44] S. Terada, K. Higaki, I. Nagashima & Y. Ito (1999) Stability and solubility of electrolyte matrix support material for molten carbonate fuel cells, Journal of Power Sources 83, 227-230
[45] K. Joon (1996) Critical issues and future prospects for molten carbonate fuel cells, Journal of Power Sources 61, 129-133
[46] C.W. Bale, P. Chartrand, S.A. Degterov, G. Eriksson, K. Hack, R. Ben Mahfoud, J. Melançon, A.D. Pelton & S. Petersen (2002) FactSage thermochemical software and databases, Calphad 26 (2), 189-228
[47] M. Mogensen & T. Lindegaard (1993) The kinetics of hydrogen oxidation on a Ni-YSZ SOFC electrode at 1000oC, Proc. 3rd Int. Symp on Solid Oxide Fuel Cells, The Electrochemical Society Proc. (93-4), 484-493
[48] F.P.F. van Berkel, F.H. van Heuveln & J.P.P. Huijsmans (1994) Characterization of solid oxide fuel cell electrodes by impedance spectroscopy and I-V characteristics, Solid State Ionics 72, 240-247
160 Bibliography
[49] J. Mizusaki, H. Tagawa, T. Saito, T. Yamamura, K. Kamitani, K. Hirano, S. Ehara, T. Takagi, T. Hikita, M. Ippommatsu, S. Nakagawa & K. Hashimoto (1994) Kinetic studies of the reaction at the nickel pattern electrode on YSZ in H2-H2O atmospheres, Solid State Ionics 70/71, 52-58
[50] M. Mogensen & S. Skaarup (1996) Kinetic and geometric aspects of solid oxide fuel cell electrodes, Solid State Ionics, 86-88, 1151-1160
[51] A.V. Virkar, J. Chen, C. W. Tanner, Jai-Woh Kim (2000) The role of electrode microstructure on activation and concentration polarizations in solid oxide fuel cells, Solid State Ionics 131, 189-198
[52] D.W Dees, T.D. Claar, T.E. Easler, D.C. Fee & F.C. Mrazek (1987) Conductivity of porous Ni/ZrO2-Y2O3 cermets, Journal of the Electrochemical Society 134 (9), 2141-2146
[53] T. Kawada, N. Sakai, H. Yokokawa, M. Dokiya, M. Mori & T. Iwata (1990) Char-acteristics of slurry-coated nickel zirconia cermet anodes for Solid Oxied Fuel Cells, Journal of the Electrochemical Society 137 (10), 3042-3047
[54] W.Z. Zhu & S.C. Deevi (2003) A review on the status of anode materials for solid oxide fuel cells, Materials Science & Engineering A362, 228-239
[55] H. Koide, Y. Someya, T. Yoshida & T. Maruyama (2000) Properties of Ni/YSZ cermet as anode for SOFC, Solid State Ionics 132, 253-260
[56] T. Kawada, N. Sakai, H. Yokokawa, M. Dokiya, M. Mori & T. Iwata (1990) Structure and polarization characteristics of solid oxide fuel cell anodes, Solid State Ionics 40/41, 402-406
[57] M. Brown, S. Primdahl & M. Mogensen (2000) Structure/performance relations for Ni/yttria-stabilized zirconia anodes for solid oxide fuel cells, Journal of The Electro-chemical Society 147 (2), 475-485
[58] S. Primdahl & M. Mogensen (1997) Oxidation of hydrogen on Ni/yttria-stabilized zirconia cermet anodes, Journal of the Electrochemical Society, 144 (10), 3409-3419 [59] D.W. Dees, U. Balachandran, S.E. Dorris, J.J. Heiberger, C.C. McPheeters & J.J.
Picciolo (1989) Interfacial eects in monolithich solid oxide fuel cells, Proc. 1st Int.
Symp. Solid Oxide Fuel Cells, The Electrochemical Society Proc. (89-11), 317-321 [60] H. Tu & U. Stimming (2005) Advances, aging mechanisms and lifetime in solid-oxide
fuel cells, Journal of Power Sources 127, 284-293
[61] K. Vels Jensen (2002) The Nickel-YSZ interface - Structure, composition and elec-trochemical properties at 1000oC, PhD thesis, Risø National Laboratory, Roskilde, Denmark
[62] S.C. Singhal & K. Kendall (2003) High Temperature Solid Oxide Fuel Cells - Fun-damentals, design and applications, Elsevier, UK
Bibliography 161 [63] R.N Basu, G. Blaÿ, H.P. Buchkremer, D. Stöver, F. Tietz, E. Wessel & I.C. Vinke (2001) Fabrication of simplied anode supported planar SOFCs - A recent attempt, Proc. 7th Int. Symp. Solid Oxide Fuel Cells, The Electrochemical Society Proc. (2001-16), 995-1001
[64] S.P.S. Badwal (1992) Zirconia-based electrolytes: microstructure, stability and ionic conductivity, Solid State Ionics 52, 23-32
[65] R.M Dell & A. Hopper in P. Hagenmuller & W. van Gool (eds.) (1978) Solid elec-trolytes - General principles, characterization, materials, application, Academic Press, New York, USA
[66] I.R. Gibson, G.P. Dranseld & J.T.S. Irvine (1998) Inuence of yttia concentra-tion upon electrical properties and susceptibility to ageing of yttria-stabilised zirconias, Journal of the European Ceramic Society 18, 661-667
[67] S. Ikeda, O. Sakurai, K. Uematsu, N. Mizutani & M. Kato (1985) Electrical con-ductivity of yttia-stabilized zirconia single crystals, Journal of Materials Science 20, 4593-4600
[68] C. Haering, A. Roosen & H. Schichl (2005) Degradation of the electrical conductivity in stabilised zirconia systems Part I: yttria-stabilised zirconia, Solid State Ionics 176, 253-259
[69] C.C. Appel, N. Bonanos, A. Horsewell & S. Linderoth (2001) Ageing behaviour of zirconia stabilised by yttria and manganese oxide, Journal of Materials Science 36, 4493-4501
[70] C. Clausen, C. Bagger, J.B. Bilde-Sørensen & A. Horsewell (1994) Microstrucu-tral and microchemical characterization of the interface between La0.85Sr0.15MnO3 and Y2O3-stabilized ZrO2, Solid State Ionics 70/71, 59-64
[71] S.P. Jiang & S.H. Chan (2004) A review of anode materials development in solid oxide fuel cells, Journal of Materials Science 39, 4405-4439
[72] C.W. Tanner, K. Fung & A.V. Virkar (1997) The eect of porous composite electrode structure on solid oxide fuel cell performance - I. Theoretical analysis, Journal of The Electrochemical Society 144 (1), 21-30
[73] T. Norby, O.J. Velle, H. Leth-Olsen & R. Tunold (1993) Reaction resistance in relation to three phase boundary length of Ni/YSZ electrodes, Proc. 3rd Int. Symp.
Solid Oxide Fuel Cells, The Electrochemical Society Proc. (93-4), 473-478
[74] Y. Matsuzaki & I. Yasuda (2000) Electrochemical oxidation of H2 and CO in a H2-H2O-CO-CO2 system at the interface of a Ni-YSZ cermet electrode and YSZ elec-trolyte, Journal of the Electrochemical Society 147 (5), 1630-1635
[75] J. Mizusaki, H. Tagawa, T. Saito, K. Kamitani, T. Yamamura, K. Hirano, S. Ehara, T. Takagi, T. Hikita, M. Ippommatsu, S. Nakagawa & K. Hashimoto (1993) Prepara-tion of nickel pattern electrodes on YSZ and their electrochemcial properties in H2-H2O atmosphere, Proc. 3rd Int. Symp. Solid Oxide Fuel Cells, The Electrochemical Society Proc. (93-4), 533-541
162 Bibliography
[76] S.P.S. Badwal & K. Foger (1997) Materials for solid oxide fuel cells, Materials Forum 21, 187-244
[77] Y.C. Hsiao & J.R. Selman (1997) The degradation of SOFC electrodes, Solid State Ionics 98, 33-38
[78] S. Primdahl & M. Mogensen (2000) Durability and thermal cycling of Ni/YSZ cermet anodes for solid oxide fuel cells, Journal of Applied Electrochemistry 30, 247-257 [79] A. Gubner, H. Landes, J. Metzger, H. Seeg & R. Stübner (1997) Investigations into
the degradation of the cermet anode of a solid oxide fuel cell, Proc. 5th Int. Symp.
Solid Oxide Fuel Cells, The Electrochemical Society Proc. (97-40), 844-850
[80] T. Iwata (1996) Characterization of Ni-YSZ anode degradation for substrate-type solid oxide fuel cells, Journal of the Electrochemical Society 143 (5), 1521-1525 [81] S.C. Singhal (1997) Recent progress in tubular solid oxide fuel cell technology, Proc.
5th Int. Symp. Solid Oxide Fuel Cells, The Electrochemical Society Proc. (97-40), 37-50
[82] M. Pastula, R. Boersma, D. Prediger, M. Perry, A. Horvath, J. Devitt & D. Gosh (2000) Development of low temperature SOFC systems for remote power applications, Proc. 4th European Solid Oxide Fuel Cell Forum 1, 123-132
[83] D. Stolten, R. Späh & R. Schamm (1997) Status of SOFC development at Daimler-Benz/Dornier, Proc. 5th Int. Symp. Solid Oxide Fuel Cells, The Electrochemical So-ciety Proc. (97-40), 88-93
[84] C.C. Chen, M.M. Nasrallah & H.U. Anderson (1993) Cathode/electrolyte interac-tions and their expected impact on SOFC performance, Proc. 3rd Int. Symp. Solid Oxide Fuel Cells, The Electrochemical Society Proc. (93-4), 598-612
[85] I. Alstrup, J.R. Rostrup-Nielsen & S. Røen (1981) High temperature hydrogen sulde chemisorption on nickel catalysts, Applied Catalysis 1, 303-314
[86] Y. Matsuzaki & I. Yasuda (2000) The posioning eect of sulfur-containing impurity gas on SOFC anode: Part I. Dependence on temperature, time and impurity concen-tration, Solid State Ionics 132, 261-269
[87] Y. Matsuzaki & I. Yasuda (2001) Eect of a sulfur-containing impurity on electro-chemical properties of a Ni-YSZ cermet electrode, Proc. 7th Int. Symp. Solid Oxide Fuel Cells, The Electrochemical Society Proc. (2001-16), 769-782
[88] J. Geyer, H. Kohlmüller, H. Landes & R. Stübner (1998) Investigations into the kinetics of the Ni-YSZ-cermet-anode of a solid oxide fuel cell, Proc. 5th Int. Symp.
Solid Oxide Fuel Cells, The Electrochemical Society Proc. (97-40), 585-594
[89] S. Primdahl & M. Mogensen (1999) Limitations in the hydrogen oxidation rate on Ni/YSZ anodes, Proc. 6th Int. Symp. Solid Oxide Fuel Cells, The Electrochemical Society Proc. (99-19), 530-540
[90] S.C. Singhal (2000) Advances in solid oxide fuel cell technology, Solid State Ionics 135, 305-313
Bibliography 163 [91] M.A. Petrik, C.E. Milliken, R.C. Ruhl % B.P. Lee (1998) Status of TMI solid oxide
fuel cell technology, 1998 Fuel Cell Seminar, California, 124-127
[92] M. Mogensen, K. Vels Jensen, M. Juhl Jørgensen and S. Primdahl (2002) Progress in understanding SOFC electrodes, Solid State Ionics 150, 123-129
[93] S. Onuma, A. Kaimai, K. Kawamura, Y. Nigara, T. Kawada, J. Mizusaki, H. Tagawa (2000) Inuence of the coexisting gases on the electrochemical reaction rates between 873 and 1173 K in a CH4-H2O/Pt/YSZ system, Solid State Ionics 132, 309-331 [94] O. Costa-Nunes, R.J. Gorte & J.M. Vohs (2005) Comparison of the performance
of Cu-CeO2-YSZ and Ni-YSZ composite anodes with H2, CO, and syngas, Journal of Power Sources 141, 241-249
[95] A. Schuler, T. Zähringer, B. Doggwiler & A. Rüegge (2000) Sulzer Hexis SOFC running on home heating oil, Proceedings of the Fourth European Solid Oxide Fuel Cell Forum 1, 107-114
[96] G.A. Tompsett, C. Finnerty, K. Kendall, T. Alston & N.M. Sammes (2000) Novel applications for micro-SOFCs, Journal of Power Sources 86, 376-382
[97] N.M. Sammes, R.J. Boersma & G.A. Tompsett (2000) Micro-SOFC system using butane fuel, Solid State Ionics 135, 487-491
[98] Z. Zhan, J. Liu & S.A. Barnett (2004) Operation of anode-supported solid oxide fuel cells on propane-air mixtures, Applied Catalysis A: General 262, 255-259
[99] J. Liu & S.A. Barnett (2003) Operation of anode-supported solid oxide fuel cells on methane and natural gas, Solid State Ionics 158, 11-16
[100] K. Ahmed, J. Gamman & K. Föger (2002) Demonstration of LPG-fueled solid oxide fuel cell systems, Solid State Ionics 152-153, 485-492
[101] G.J. Saunders & K. Kendall (2002) Reactions of hydrocarbons in small tubular SOFCs, Journal of Power Sources 106, 258-263
[102] G.J. Saunders, J. Preece & K. Kendall (2004) Formulating liquid hydrocarbon fuels for SOFCs, Journal of Power Sources 131, 23-26
[103] S. Assabumrungrat, V. Pavarajarn, S. Charojrochkul & N. Laosiripojana (2004) Thermodynamic analysis for a solid oxide fuel cell with direct internal reforming fueled by ethanol, Chemical Engineering Science 59, 6015-6020
[104] J. Stainforth & K. Kendall (1998) Biogas powering a small tubular solid oxide fuel cell, Journal of Power Sources 71, 275-277
[105] J. Stainforth & K. Kendall (2000) Cannock landll gas powering a small tubular solid oxide fuel cell - a case study, Journal of Power Sources 86, 401-403
[106] A. Wojcik, H. Middleton, I. Damopoulos % J. Van herle (2003) Ammonia as a fuel in solid oxide fuel cells, Journal of Power Sources 118, 342-348
[107] G. Eriksson % K. Hack (1990) ChemSage - A computer program for the calculation of complex chemical equilibria, Metallurgical Transactions B 21 B, 1013-1023
164 Bibliography
[108] K. Sasaki, Y. Hori, R. Kikuchi, E. Eguchi, A. Ueno, H. Takeuchi, M. Aizawa, K.
Tsuijumoto, H. Tajiri, H. Nishikawa & Y. Uchida (2002) Current-voltage character-istics and impedance analysis of solid oxide fuel cells for mixed H2 and CO gases, Journal of The Electrochemical Society 149 (3), A227-A233