RITASKRÁ / Publications

RITRÝNDAR GREINAR / Articles in peer-reviewed journals:

2009:

Tom Brenner, Taco Nicolai, Ragnar Jóhannsson. 2009. Rheology of thermo-reversible fish protein isolate gels. Food Research International. 42 (8), 915-924. Grein / Article

Tom Brenner, Ragnar Jóhannsson, T. Nicolai. 2009. Characterization and thermo-reversible gelation of cod muscle protein isolates. Food Chemistry, 115, 26-31   Article / Grein

Tom Brenner, Ragnar Jóhannsson, T. Nicolai. 2009. Characterization of fish myosin aggregates using static and dynamic light scattering. Food Hydrocolloids, 23(2) 296-305. Grein / Article

2008:

Tom Brenner, Ragnar Jóhannsson, T. Nicolai. 2008. Characterization and thermo-reversible gelation of cod muscle protein isolates. Food Chemistry (In print - Aavailable online November 2008) doi:10.1016/j.foodchem.2008.11.046

2007:

Laurent Vandanjon, Ragnar Johannsson, Maryse Derouiniot, Patrick Bourseau, Pascal Jaouen. 2007. Concentration and purification of blue whiting peptide hydrolysates by membrane processes. Journal of Food Engineering, 83: 581-589 Lesa grein  Grein / Article

1996:
Christophe Chassenieux, Ragnar Jóhannsson, Dominique Durand, Taco Nicolai, Pierre Vanhoorne and Robert Jérôme. 1996. Telechelic ionomers studied by light scattering and dynamic mechanical measurements. Colloids and Surfaces, 112 , 155-162.

1995:
Marilena Vasilescu, Agneta Caragheorgheopol, Mats Almgren, Jan Alsins and Ragnar Jóhannsson. 1995. Structure and Dynamics of Nonionic Polyoxyethoxlenic Reverse Micelles by Time-Resolved Fluorescence Quenching. Langmuir 11, 2893.

Ragnar Jóhannsson, Cristhophe Chasseniux, Dominique Durand, Taco Nicolai, Pierre Vanhoorne and Robert Jérôme Dynamic. 1995. Properties of a Transient Network formed by Telechelic Ionomers Studied by Dynamic Light Scattering and Dynamic Mechanical Analysis, Macromolecules 28, 8504.

1994:
Ragnar Jóhannsson and Paul D.I. Fletcher. 1994. Time-resolved Fluorescence Probing of Oil-in-water Microemulsions stabilised by Non-ionic Surfactants. J.Chem Soc. Faraday Trans. 90, 3567.

1993:
Mats Almgren and Ragnar Jóhannson. 1993. Diffusion-influenced Deactivation of Excited Species in AOT Microemulsions, below, at and above the Percolation threshold. Journal de Physique iv 3, 81.

Ragnar Jóhannsson and Mats Almgren. 1993. Inter-droplet Exchange Rate and Activation Energy of Fusion in AOT W/O Microemulsion in the Cluster Regime., Langmuir, 9, 2879.

Ragnar Jóhannsson Mats Almgren and Jan Christer Eriksson. 1993. Polydispersity of AOT Droplets Measured by Time Resolved Fluorescence Quenching. J. Phys. Chem. 97, 8590.

Ragnar Jóhannsson, Mats Almgren and Reinhold Shomäcker. 1993. Diffusion Controlled Reaction Kinetics in Bicontinuous Microemulsions of AOT and C12E5 Studied by Triplet State Quenching. Langmuir, 9, 1269.

1992:
Mats Almgren and Ragnar Jóhannsson. 1992. Deactivation of Excited by Diffusion Controlled Quenching in Clusters of Reversed Micelles. J. Phys. Chem., 96, 9512.

Mats Almgren, Jan Alsins and Ragnar Jóhannsson. 1992. Effects of Dimensionality on Diffusion-controlled Deactivation of excited species. Proc. Ind Academy of Sci. 104.

1991:
Ragnar Jóhannsson Mats Almgren and Jan Alsins. 1991. Fluorescence and Phosphorescence Study of AOT/H2O/Alcane systems in the L2 Reversed Micellar Phase. J. Phys. Chem., 95, 3819-3823.

BÆKUR OG BÓKAKAFLAR / Books and book chapters:

Guðjón Þorkelsson, Sjöfn Sigurgísladóttir, Margrét Geirsdóttir, Ragnar Jóhannsson, F Guérard, A Chabeaud, P Bourseau, L Vandanjon, P Jaouen, M Chaplain-Derouiniot, M Fouchereau-Peron, O Martinez-Alvarez, Y Le Gal, R Ravallec-Ple, L Picot, J P Berge, C Delannoy, G Jakobsen, I Johansson, I Batista, C.Pires. 2008. Mild processing techniques and development of functional marine protein and peptide ingredients In: Improving seafood products for the consumer. Edited by T. Börresen. Cambridge, Woodhead Publishing Ltd.  Meira um bókina.

Kristinsson, H. G., Raghavan, S. and Johannsson, R. 2008. Antioxidative properties of fish protein hydrolysates. In: Seafood Quality, Safety and Health Effects; C. Alasalvar, K. Miyashita, F. Shahidi and U. Wanasundara; Oxford, UK; Blackwell Publishing. In Press

Wang Tao, Rósa Jónsdóttir, Guðrún Ólafsdóttir, Hörður G. Kristinsson and Ragnar Jóhannsson. 2008. Phytochemical properties of macroalgae. In: Seafood Quality, Safety and Health Effects; C. Alasalvar, K. Miyashita, F. Shahidi and U. Wanasundara; Oxford, UK; Blackwell Publishing. In Press.

Aurélie Chabeaud, Laurent Vandanjon, Pascal Jaouen, Patrick Bourseau, Charles Delannoy,Ragnar Jóhannsson, Guðjón Þorkelsson and Fabienne Guerard. 2006. Evaluation of antioxidant activities in by-product hydrolysates, fractionation and concentration of active molecules using separation technologies (ultra- and nanofiltration technologies), p 419.

Johannsson Ragnar (Editor). 2001. Aquafarmer Practical farming guide. I. Farming of Arctic Charr;II Farming of Eel.

Kvikasilfur í uppistöðulónum á grónu landi, Þráinn Friðriksson, Ragnar Jóhannsson Lynne Rogers og Elsa Þórey Eysteinsdóttir. 2000. Náttúrufræðingurinn 70 (1), bls 27-36.

SKÝRSLUR / Reports:

2010:

Ragnar Jóhannsson, Helgi Thorarensen, Ólafur Ögmundarson. Betri nýting vatns í bleikjueldi/ Efficient rearing  systems for Arctic charr. Skýrsla Matís 26-10, 17 s.

2009:

Kristín Anna Þórarinsdóttir, Kolbrún Sveinsdóttir, Þóra Valsdóttir, Irek Klonowski, Aðalheiður Ólafsdóttir, Hannes Magnússon, Arnljótur Bjarki Bergsson, Ragnar Jóhannsson, Emilía Martinsdóttir. Sprautun og pæklun tilapíuflaka /Injection and brining of tilapia fillets. Skýrsla Matís 39-09, 37 s. Lokuð skýrsla. Skýrsluágrip.

Emilía Martinsdóttir, Cyprian Ogombe Odoli, Hélène L. Lauzon, Kolbrún Sveinsdóttir, Hannes Magnússon, Sigurjón Arason and Ragnar Jóhannsson. Optimal storage conditions for fresh farmed tilapia (Oreochromis niloticus) fillets. Skýrsla Matís 38-09, 74 s.

Ragnar Jóhannsson, Sjöfn Sigurgísladóttir, Guðjón Þorkelsson, Arnljótur B. Bergsson.  Hrein vöðvaprótein úr fiski / Pure muscle proteins from fish. Skýrsla Matís 19-09, 10 s.

2008:

Sigrún Mjöll Halldórsdóttir, Patricia Y. Hamaguchi, Ragnar Jóhannsson, Sigurður Hauksson, Hörður G. Kristinnsson, Guðjón Þorkelsson, 2008. Efnasamsetning og eiginleikar ufsa ísólats. Skýrsla Matís 20-08, 12 s. Lokuð skýrsla.

Guðjón Þorkelsson, Margrét Geirsdóttir, Ragnar Jóhannsson, Sigurður Hauksson, Sjöfn Sigurgísladóttir, Arnljótur Bjarki Bergsson, 2008. Fiskprótein sem fæðubótarefni. Skýrsla Matís 11-08, 18 bls.

2007:
Ragnar Jóhannsson, Þóra Valsdóttir, Sigurður Hauksson, Irek Klownoski og Tom Brenner. 2007. Framleiðsla á vöðvapróteinum úr fiski til innsprautunar í fiskflök, bita og bitablokk. Skýrsla Matís 14-07, 12 s. Lokuð skýrsla.

Tom Brenner, Ragnar Jóhannsson, Taco Nicolai. 2007. Characterization of cod myosin aggregates using static and dynamic light scattering. Skýrsla Matís 07-07, 57 bls.

2006:
Ragnar Jóhannsson, Heimir Tryggvason. 2006. Kolmunni í verðmætar sjávarafurðir. Rf skýrsla 25-06, 30 bls.

2005:
Kristín Anna Þórarinsdóttir, Þóra Valsdóttir, Katrín Ásta Stefánsdóttir, Margrét Geirsdóttir, Ragnar Jóhannsson. 2005.  The effects of protein isolate in chilled and frozen haddock fillets.  Rf skýrsla 25-05, 64 bls.

2004:
Margrét Geirsdóttir, Ragnar Jóhannsson. 2004. Kolmunni sem markfæði. Rf skýrsla 11-04, 25 bls.

2001:
Ragnar Jóhannsson, Hermann Þórðarson. 2001. Endurnýting vatns í sæeyrnaeldi. Skýrsla til Rannsóknaráðs 2001.

1998:
Ragnar Jóhannsson og Hermann Þórðarson. 1998. Efnaferli verksmiðju. Mengun og mengunarvarnir. Í Umhverfismatskýrsla fyrir Magnesíumverksmiðju á Reykjanesi VSÓ.

1997:
Ragnar Jóhannsson, Magnús Jónsson, Hermann Þórðason. 1997. Þróun olíu- og tjöruhreinsis úr tólg. Skýrsla Iðntæknistofnunar til Rannsóknaráðs.

1996:
Jóhannsson Ragnar Þórðarson Hermann. Þróun aðferða við mælingar og afloftun kolsýru í fiskeldi Skýrsla til Rannsóknaráðs 1996.

FRÆÐSLURIT / Promotional material:

Ragnar Jóhannson.  1995.   Jurtahreinsar – Gallagripir eða himnasending? Iðntæknistofnun og Prenttæknistofnun. Kynningarbæklingur fyrir prentara um notkun jurtahreinsa við hreinsun offsetprentvéla. 18 bls.

ERINDI OG VEGGSPJÖLD / Oral presentations and posters:

2009:

Emilía Martinsdóttir, Cyprian Ogombe Odoli, Hélène L. Lauzon,  Kolbrún Sveinsdóttir, Hannes Magnússon, Sigurjón Arason, Ragnar Jóhannsson. ‘Arctic' tilapia (Oreochromis niloticus) Optimal storage and transport conditions for fillets. Veggspjald á ráðstefnunni TAFT 2009, Kaupmannahöfn 15.-18. september. Veggspjaldið var valið besta veggspjald ráðstefnunnar.

2008:

Hamaguchi, P., Bergsson, A., Halldorsdottir. S.M., Thorkelsson, G., Kristinsson, H.G., Johannsson, R. 2008. Bioactivity of saithe (Pollachius virens L.) protein hydrolysates. Proceedings of the 5th world fisheries congress, October 21-24, 2008, Yokohama, Japan. Abstract.

2005:
Ragnar Jóhannsson, Margrét Geirsdóttir, Guðjón Þorkelsson, I. Batista, C. Pires. 2005. Functional properties of proteins from seafood by-products.Erindi á 2. SEAFOODplus ráðstefnunni, í Granville,Frakklandi, 5. október 2005.

Patrick Bourseau, University of South Brittanny,Frakklandi og Ragnar Jóhannsson, Rf. 2005. Aðferðir til vinnslu á próteinum og peptíðum til notkunar í matvæli. Erindi flutt á SEAFOODplusfundi sem Rf, Háskóli Íslands og Sendiráð Frakklands á Íslandi stóðu fyrir á Grand Hótel í Reykjavík, 6. maí 2005.

A.Chabeaud L.Vandanjon, P. Burseau, C. Delannoy,Ragnar Jóhannsson, Guðjón Þorkelsson, F.Guérard. 2005. Evaluation of antioxidant activities in by-product hydrolysates: fractionation and concentration of active molecules using ultra- and nanofiltration membranes. Erindi á 35. fundi WEFTA í Antwerpen, Belgíu, 19-22 september 2005.

2002:
Jóhannsson Ragnar. Design of a Large RAS Tilapia Farm Using Geothermal Water. 4th International Conference on Recirculating Aquaculture July 18-21, 2002 Roanoke Viginia.

1998:
Vistvænn kostur úr kindamör - Föstudagserindi Efnafræðiskorar Háskóla Íslands 22 október 1998 og fleiri stöðum.

1997:
Jóhannsson Ragnar. “Diffusion of gases in water” and “Oxigenation in Salmon Farming – The nordic experience” A short traning course in oxygenation Basilicata Italy Otober 1997.

VEGGSPJÖLD/Posters

Guðjón Þorkelsson, Katrín Stefánsdóttir, I. Batista, C. Delannoy, I. Johannsson, J. Gislason, Ragnar. Jóhannsson, F. Guérard, J-M. Piot, J-P. Bergé, P. Bourseau, P.Jaouen& Y. Le Gal. Fish Protein hydrolysates. Proximate analysis and physical properties. Veggspjald á The first SEAFOODplus Conference, Kaupmannahöfn, - 4.–6. október 2004.

ALMENNAR GREINAR

Ragnar Jóhansson. Ný útflutningsgrein? Hlývatnseldi á Íslandi. Fræðaþing landbúnaðarins 2010, 7, s. 55-59.

Ragnar Jóhannsson og Sigríður Hjörleifsdóttir. MateMeRight™ –besta parið í eldinu. 2010. Fræðaþing landbúnaðarins 2010, 7, s. 119-122.

ANNAÐ

Hermann Þórðarsson og Ragnar Jóhannsson Loft og vatnsmengun og mengunarvarnir. Loftdeifingarspá (Umhverfismat fyrir Alkóhóleimingar-verksmiðju. Byggð verkfræðistofa - ekki endanlega lögð fram).

KENNSLA/Teaching

Verkleg kennsla í almennri efnafræði og eðlisefnafræði á árunum 1988-1993 við Uppsalaháskóla. Kenndi fyrirlesta í Eðlisefnafræði B við Háskóla Íslands vormisseri 1999 og 2000.

Umsjón með  nemenda í lokaverkefni í umhverfisverkfræði við Landbúnaðarháskólann í Wageningen í Hollandi 1997. Lokaverkefnið hét “bioremediation in Iceland” og fjallaði um lífræna endurhæfingu á olíumenguðum jarðvegi í köldu loftslagi.