38 results on '"Litlabø, A"'
Search Results
2. Rare-Earth-Metal Methyl and Methylidene Complexes Stabilized by TpR,R′-Scorpionato LigandsSize Matters.
- Author
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Schädle, Dorothea, Litlabø, Rannveig, Meermann-Zimmermann, Melanie, Thim-Spöring, Renita, Schädle, Christoph, Maichle-Mössmer, Cäcilia, Törnroos, Karl W., and Anwander, Reiner
- Published
- 2024
- Full Text
- View/download PDF
3. Miljørapportering i oppdrettsforetak: Fast i fisken?
- Author
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Fallan, Even, primary, Granrud, Hans Roger, additional, Litlabø, Eva Annette, additional, and Rønning, John Erik, additional
- Published
- 2023
- Full Text
- View/download PDF
4. Open-Shell Early Lanthanide Terminal Imides
- Author
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Theresa E. Rieser, Renita Thim-Spöring, Dorothea Schädle, Peter Sirsch, Rannveig Litlabø, Karl W. Törnroos, Cäcilia Maichle-Mössmer, and Reiner Anwander
- Subjects
Ions ,Models, Molecular ,Colloid and Surface Chemistry ,Organometallic Compounds ,General Chemistry ,Crystallography, X-Ray ,Imides ,Biochemistry ,Lanthanoid Series Elements ,Catalysis - Abstract
Group 3- and 4f-element organometallic chemistry and reactivity are decisively driven by the rare-earth-metal/lanthanide (Ln) ion size and associated electronegativity/ionicity/Lewis acidity criteria. For these reasons, the synthesis of terminal "unsupported" imides [Ln═NR] of the smaller, closed-shell Sc(III), Lu(III), Y(III), and increasingly covalent Ce(IV) has involved distinct reaction protocols while derivatives of the "early" large Ln(III) have remained elusive. Herein, we report such terminal imides of open-shell lanthanide cations Ce(III), Nd(III), and Sm(III) according to a new reaction protocol. Lewis-acid-stabilized methylidene complexes [Tp
- Published
- 2022
5. Open-Shell Early Lanthanide Terminal Imides
- Author
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Rieser, Theresa E., primary, Thim-Spöring, Renita, additional, Schädle, Dorothea, additional, Sirsch, Peter, additional, Litlabø, Rannveig, additional, Törnroos, Karl W., additional, Maichle-Mössmer, Cäcilia, additional, and Anwander, Reiner, additional
- Published
- 2022
- Full Text
- View/download PDF
6. Short-term hydropower scheduling at watercourses with flooding risks
- Author
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Litlabø, Tormod Bjelland
- Abstract
Masteroppgåve i energi ENERGI399I
- Published
- 2022
7. Robotisert rennerensk
- Author
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Bunes, Tørres Litlabø and Fimreite, Kim Hans
- Abstract
Bacheloroppgave i ingeniørfag, elektronikk. Fakultet for ingeniør- og naturvitskap/ Institutt for datateknologi, elektroteknologi og realfag/ Høgskulen på Vestlandet, campus Haugesund. ELE350
- Published
- 2022
8. Uptake and elimination of florfenicol in Atlantic cod ( Gadus morhua) larvae delivered orally through bioencapsulation in the brine shrimp Artemia franciscana
- Author
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Roiha, Irja Sunde, Otterlei, Erling, Litlabø, Amund, and Samuelsen, Ole Bent
- Published
- 2010
- Full Text
- View/download PDF
9. 'Les de av og til i naturfagstimane?' - Ein kvalitativ studie av elevar sine erfaringar med å lesa naturfaglege tekstar
- Author
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Litlabø, Gunnhild and Birkedal, Inga Kjerstin
- Abstract
Samandrag Det å kunna lesa er ein føresetnad for å tileigna seg kunnskap og informasjon frå ulike tekstar, og uansett kva for ei utdanning eller jobb ein tek, vil god lesedugleik vera av stor verdi. Likevel har det vist seg at mange vaksne ikkje les godt nok til å fungera optimalt i kvardagen, og norske elevar har over fleire år hatt gjennomsnittlege resultat på internasjonale leseundersøkingar og kome dårlegast ut blant dei nordiske landa. Lesing er ikkje ein dugleik som skal lærast dei første åra på skulen, men krev derimot kontinuerleg utvikling i møte med stadig meir avanserte tekstar. I denne masteroppgåva ønskjer eg å sjå på leseundervisning i naturfagstimane, og kva erfaringar elevar på mellomtrinnet har med å lesa naturfaglege tekstar. Problemstilliga for oppgåva er: «Kva erfaringar har elevar på mellomtrinnet når det gjeld å lesa i naturfag, og kva strategiar brukar dei for å lesa ein fagtekst?». Oppgåva har også tre forskingsspørsmål: 1. I kva grad les elevane i naturfagstimane? 2. Kva erfaringar har elevane med ulike naturfaglege sjangrar? 3. Kva erfaringar har elevane med å nytta lesestrategiar når dei les ein fagtekst i naturfag? Denne masteroppgåva er ein kvalitativ studie som baserer seg på fire fokusgruppeintervju av totalt elleve elevar frå 5. og 6. trinn. I intervjua svarte elevane på spørsmål knytte til deira erfaringar kring det å lesa naturfaglege tekstar og kva lesestrategiar dei nyttar. Funna har blitt kategorisert etter dei tre forskingsspørsmåla, og drøfta opp mot subkategorien på kva måte?. Elevane i studien var i utgangspunktet lite medvitne på at dei les i naturfagstimane, men etter kvart kom det likevel fram at dei les ein god del i timane, og at dei les til dels varierte tekstar. Funna indikerer at det ligg eit stort potensiale i kva type undervisning elevane får. Det kan sjå ut som om det er trong for ei meir eksplisitt undervisning, med fokus på naturfaglege sjangrar og fagspesifikk leseopplæring. Andre sentrale moment er knytte til korleis elevane nyttar lesestrategiar, og korleis dei lærer fagspesifikke ord og omgrep. Studien indikerer at det kan vera føremålstenleg at leseopplæring vert sterkare vektlagt i naturfagstimane og bør bli ein integrert del av undervisninga. Nøkkelord Eksplisitt undervisning, fagspesifikk leseopplæring, lesestrategiar, lesing som grunnleggjande dugleik i naturfag.
- Published
- 2021
10. Miljørapportering i oppdrettsforetak: Fast i fisken?
- Author
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Fallan, Even, Granrud, Hans Roger, Litlabø, Eva Annette, and Rønning, John Erik
- Subjects
VDP::Samfunnsvitenskap: 200::Økonomi: 210 ,Samfunnsvitenskap: 200::Biblioteks- og informasjonsvitenskap: 320::Dokumentasjonsvitenskap: 325 [VDP] ,Samfunnsvitenskap: 200 [VDP] ,Miljørapportering ,VDP::Landbruks- og Fiskerifag: 900::Fiskerifag: 920 ,Landbruks- og Fiskerifag: 900::Fiskerifag: 920::Akvakultur: 922 [VDP] ,Rapporteringskvalitet - Abstract
Dette er en studie av miljørapporteringspraksis for en stor andel av norske lakseoppdrettsforetak. Data om miljørapportering i årsberetningen for 2019 og annen informasjon som årsberetningen henviser til, er studert ved innholdsanalyse, og resultatene er analysert i lys av adopsjonsteori. Den gjennomsnittlige rapporteringskvaliteten blant ikke-børsnoterte foretak i studiens populasjon er så lav at den anses verdiløs for ressursallokerings- og kontrollformål. Det kan ikke skyldes tekniske eller ressursmessige utfordringer ved rapporteringen, siden prøvbarheten er høy og kompleksiteten lav. Trolig er rapporteringspraksisen konsekvensen av oppfattet lav legitimitetsrisiko ved lavkvalitetsrapportering (og brudd på regnskapsloven) og lav synlighet og relativ fordel ved høykvalitetsrapportering. Myndigheter, revisorer, kunder, finansinstitusjoner, miljøorganisasjoner mv. kan dermed endre disse forutsetningene og tvinge selskapene til å ta miljørapportering på alvor. Børsnoterte oppdrettsforetak har gjennomsnittlig høyere rapporteringskvalitet. Et par selskaper er i norgestoppen, uavhengig av bransje. Men selv disse har klart forbedringspotensial. Blant annet medfører manglende redegjørelse for rapporteringsprinsipper (à la årsregnskapets prinsippnote) og det at ikke hele rapporteringen er attestert med høy grad av sikkerhet, at regnskapsbrukeren ikke kan vite om informasjonen er komplett, nøytral, feilfri, sammenlignbar, verifiserbar/verifisert osv. Dette gir lavere verdi for ressursallokerings- og kontrollformål. Samtidig er miljørapporteringskvaliteten i Norge generelt lav, ikke kun i oppdrettsnæringen. Lakseoppdrett har imidlertid stor økonomisk betydning og vesentlige miljøvirkninger. Miljørapportering av høy kvalitet er derfor relevant både som beslutningsgrunnlag for interessenter og incentiv for foretaket til å bedre miljøprestasjonene. Det må forventes høyere rapporteringskvalitet i oppdrettsnæringen framover.
- Published
- 2021
11. Virtual Crash Testing of a Frangible Aluminum Highway Gantry
- Author
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Laastad, Torbjørn, Litlabø, Even Renolen, and Rølvåg, Terje
- Abstract
Tradisjonelt utføres fullskala kollisjonstesting for å vurdere sikkerhetsytelsen av ettergivende konstruksjoner for veiutstyr. Denne oppgaven presenterer virtuell kollisjonstesting av en Lattix 4438 trafikkportal utført i samsvar med EN12767. Lattix er et norsk selskap som produserer og utvikler ettergivende aluminiumsmaster for luftfart og veitrafikk. Det var ønskelig å avgjøre om portalen kunne klassifiseres som ikke-energiabsorberende. Simuleringene ble utført i Abaqus eksplisit, basert på en detaljert FE-modell, som inkluderer alle relevante strukturelle komponenter, kontakter, grensebetingelser og boltforbindelser. Statens vegvesen supplerte kjøretøysmodellen som ble brukt i simuleringene. Akselerasjons- og hastighetsdata ble hentet ut fra simuleringene for beregning av Acceleration Severity Index (ASI) og Theoretical Head Impact Velocity (THIV). Disse parametrene er indikatorer for potensiell personskade under en krasj. ASI- og THIV-verdiene til portalen oppfyller kravene fra EN12767 for en ikke-energiabsorberende struktur med betegnelse 100NE2. Samplingsraten ble vist å være kritisk for nøyaktigheten av ASIverdier, og en samplingsrate på minimum 40 kHz anbefales. Simuleringer viser at bruddlasten til baseboltene har større innvirkning på ASI enn forbindelsen mellom ben og tverrliggeren. Torsjon i tverrliggeren kan være et problem og bør undersøkes videre. Dette ble ikke undersøkt i denne oppgaven grunnet høye simuleringstider (41h for 0,275 s) simulert tid). Ikke-lineære statiske analyser ble utført, noe som viste at portalen overlever en WL5 vindlastkategori for portal med en sentermast og WL7 vindlastkategori for to sentermaster. Traditionally, full-scale crash testing is performed to assess the passive safety performance of roadside structures. This thesis presents virtual crash testing of a Lattix 4438 highway gantry in accordance with EN12767. Lattix is a Norwegian company producing and developing frangible aluminum masts for aviation and road traffic. The objective was to determine if the gantry could be classified as non-energy absorbing. Simulations were performed in Abaqus Explicit, based on a detailed FE assembly model including all relevant structural components, contacts, boundary conditions, and bolt connections. The Norwegian Public Road Administration supplied the vehicle model used in the simulations. Acceleration and velocity data were extracted from the simulations for calculating Acceleration Severity Index (ASI) and Theoretical Head Impact Velocity (THIV). These parameters are indicators of the potential occupant injury during a crash. The ASI and THIV values for the gantry fulfill the EN12767 requirements for a non-energy absorbing structure with designation 100NE2. The sampling rate was found critical for the accuracy of ASI values, and a sampling rate of minimum 40 kHz is recommended. Simulations show that the fracture load of the base bolts has a larger impact on ASI than the connection between leg and transom. Torsion of the transom may be an issue and should be investigated further. This was not investigated in this thesis due to the high simulation times (41h for 0.275 s simulated time). Non-linear static wind load analyses were performed, proving that the gantry survives a WL5 wind load category for single center mast configurations and WL7 wind load category for double center mast configuration.
- Published
- 2019
12. Virtual Crash Testing of Frangible Aluminum Highway Gantry
- Author
-
Litlabø, Even Renolen, Laastad, Torbjørn, and Rølvåg, Terje
- Abstract
Tradisjonelt utføres fullskala kollisjonstesting for å vurdere sikkerhetsytelsen av ettergivende konstruksjoner for veiutstyr. Denne oppgaven presenterer virtuell kollisjonstesting av en Lattix 4438 trafikkportal utført i samsvar med EN12767. Lattix er et norsk selskap som produserer og utvikler ettergivende aluminiumsmaster for luftfart og veitrafikk. Det var ønskelig å avgjøre om portalen kunne klassifiseres som ikke-energiabsorberende. Simuleringene ble utført i Abaqus eksplisit, basert på en detaljert FE-modell, som inkluderer alle relevante strukturelle komponenter, kontakter, grensebetingelser og boltforbindelser. Statens vegvesen supplerte kjøretøysmodellen som ble brukt i simuleringene. Akselerasjons- og hastighetsdata ble hentet ut fra simuleringene for beregning av Acceleration Severity Index (ASI) og Theoretical Head Impact Velocity (THIV). Disse parametrene er indikatorer for potensiell personskade under en krasj. ASI- og THIV-verdiene til portalen oppfyller kravene fra EN12767 for en ikke-energiabsorberende struktur med betegnelse 100NE2. Samplingsraten ble vist å være kritisk for nøyaktigheten av ASIverdier, og en samplingsrate på minimum 40 kHz anbefales. Simuleringer viser at bruddlasten til baseboltene har større innvirkning på ASI enn forbindelsen mellom ben og tverrliggeren. Torsjon i tverrliggeren kan være et problem og bør undersøkes videre. Dette ble ikke undersøkt i denne oppgaven grunnet høye simuleringstider (41h for 0,275 s) simulert tid). Ikke-lineære statiske analyser ble utført, noe som viste at portalen overlever en WL5 vindlastkategori for portal med en sentermast og WL7 vindlastkategori for to sentermaster. Traditionally, full-scale crash testing is performed to assess the passive safety performance of roadside structures. This thesis presents virtual crash testing of a Lattix 4438 highway gantry in accordance with EN12767. Lattix is a Norwegian company producing and developing frangible aluminum masts for aviation and road traffic. The objective was to determine if the gantry could be classified as non-energy absorbing. Simulations were performed in Abaqus Explicit, based on a detailed FE assembly model including all relevant structural components, contacts, boundary conditions, and bolt connections. The Norwegian Public Road Administration supplied the vehicle model used in the simulations. Acceleration and velocity data were extracted from the simulations for calculating Acceleration Severity Index (ASI) and Theoretical Head Impact Velocity (THIV). These parameters are indicators of the potential occupant injury during a crash. The ASI and THIV values for the gantry fulfill the EN12767 requirements for a non-energy absorbing structure with designation 100NE2. The sampling rate was found critical for the accuracy of ASI values, and a sampling rate of minimum 40 kHz is recommended. Simulations show that the fracture load of the base bolts has a larger impact on ASI than the connection between leg and transom. Torsion of the transom may be an issue and should be investigated further. This was not investigated in this thesis due to the high simulation times (41h for 0.275 s simulated time). Non-linear static wind load analyses were performed, proving that the gantry survives a WL5 wind load category for single center mast configurations and WL7 wind load category for double center mast configuration.
- Published
- 2019
13. Kontinuitet i heimesjukepleie til eldre menneske med demens
- Author
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Litlabø, Malene Taranger
- Abstract
Bakgrunn: I mi sjukepleieutdanning har eg hatt praksis i heimesjukepleie. I denne praksisen erfarte eg å møte ulike brukarar og deira pårørande og fekk innsyn i korleis samarbeid mellom brukar, pårørande og offentleg helseteneste var på godt og vondt. Søk på internett i forbindelse med ei oppgåve gjorde meg oppmerksam på ein artikkel som hevda at brukarane møter i snitt 17 personar på fire veker. Dette gjorde med nyfiken på temaet og eg ønsker difor meir kunnskap om dette temaet for å ta kunnskapsbaserte val ved seinare utøving av omsorgshjelp. Problemstilling: «Korleis kan ein betre kontinuitet i pasientforlaup for personar med demens, som bur heime?» Oppgåva si hensikt: Hensikta med denne oppgåva er å belyse og auke kunnskapsnivået om kontinuitet i pasientforlaup for heimebuande personar som lid av demens. Metode: Oppgåva er ei systematisk litteraturstudie. Dei fire relevante artiklane eg fann er drøfta opp mot Kari Martinsen si omsorgsteori, mine eigne erfaringar og anna relevant teoretiske materiale. Resultat: Ved å presentere pasientar, pårørande og sjukepleiarar sine erfaringar kjem det tydleg fram at kontinuitet bygger på tre ulike faktorar: personkontinuitet, informasjonskontinuitet og organisatorisk kontinuitet. Felles for desse tre er at dokumentasjon, informasjon, kommunikasjon og relasjonsbygging er sentralt, samt god koordinering i helsetenesta for å sikre tilstrekkeleg tid og kvalitet på pleie. I tillegg kjem det tydlege fram at å lytte til både pasient og pårørande er naudsynt for å kartlegge hjelpebehovet og ønsker, og på den måten sikre kvalitet på pleie. Oppsummering: Samarbeid med god kommunikasjon og kunnskap om pasient og pårørande sin situasjon, samt god koordinering av helsetenesta, hjelper sjukepleiar til å sikre kontinuitet i pasientforlaupet. Nøkkelord: Demens, kontinuitet i pleie, sjukepleier erfaringar, pårørande, heimesjukepleie
- Published
- 2017
14. Ca. Branchiomonas cysticola, Ca. Piscichlamydia salmonis and Salmon Gill Pox Virus transmit horizontally in Atlantic salmon held in fresh water
- Author
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Duncan J. Colquhoun, Mona Cecilie Gjessing, Anne-Gerd Gjevre, H. T. Solheim, Mark D. Powell, J Wiik-Nielsen, A. Litlabø, and Anja B. Kristoffersen
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Veterinary (miscellaneous) ,Population ,Salmo salar ,Fresh Water ,Poxviridae Infections ,Aquatic Science ,Biology ,Microbiology ,03 medical and health sciences ,Fish Diseases ,Aquaculture ,Molecular genetics ,medicine ,Animals ,education ,Burkholderiales ,education.field_of_study ,Chlamydiales ,Ecology ,business.industry ,Norway ,Poxviridae ,Waterborne diseases ,Histology ,Aquatic animal ,04 agricultural and veterinary sciences ,Hyperplasia ,medicine.disease ,biology.organism_classification ,030104 developmental biology ,040102 fisheries ,0401 agriculture, forestry, and fisheries ,business ,Gram-Negative Bacterial Infections ,Bacteria - Abstract
Elucidation of the role of infectious agents putatively involved in gill disease is commonly hampered by the lack of culture systems for these organisms. In this study, a farmed population of Atlantic salmon pre-smolts, displaying proliferative gill disease with associated Candidatus Branchiomonas cysticola, Ca. Piscichlamydia salmonis and Atlantic salmon gill pox virus (SGPV) infections, was identified. A subpopulation of the diseased fish was used as a source of waterborne infection towards a population of naive Atlantic salmon pre-smolts. Ca. B. cysticola infection became established in exposed naive fish at high prevalence within the first month of exposure and the bacterial load increased over the study period. Ca. P. salmonis and SGPV infections were identified only at low prevalence in exposed fish during the trial. Although clinically healthy, at termination of the trial the exposed, naive fish displayed histologically visible pathological changes typified by epithelial hyperplasia and subepithelial inflammation with associated bacterial inclusions, confirmed by fluorescent in situ hybridization to contain Ca. B. cysticola. The results strongly suggest that Ca. B. cysticola infections transmit directly from fish to fish and that the bacterium is directly associated with the pathological changes observed in the exposed, previously naive fish.
- Published
- 2016
15. Tris(pyrazolyl)borate Complexes of the Alkaline-Earth Metals: Alkylaluminate Precursors and Schlenk-Type Rearrangements
- Author
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Reiner Anwander, Cäcilia Maichle-Mössmer, Rannveig Litlabø, H. Martin Dietrich, Olaf Michel, and Karl W. Törnroos
- Subjects
Steric effects ,Alkaline earth metal ,Chemistry ,Magnesium ,Organic Chemistry ,Inorganic chemistry ,chemistry.chemical_element ,Medicinal chemistry ,Inorganic Chemistry ,Metal ,chemistry.chemical_compound ,Cyclopentadienyl complex ,visual_art ,visual_art.visual_art_medium ,Salt metathesis reaction ,Physical and Theoretical Chemistry ,Homoleptic ,Derivative (chemistry) - Abstract
A series of 3,5-substituted tris(pyrazolyl)borate (TpR,Me; R = Me, Ph, tBu) complexes of the alkaline-earth metals (Mg, Ca, Ba) was synthesized by salt metathesis reactions. The influence of different organometallic precursors on Schlenk-type rearrangement reactions was studied, putting emphasis on the metal size and the steric encumbrance of the Tp ligands. Magnesium alkyls MgR2 (R = AlMe4, CH3) react with KTpR,Me to form the heteroleptic complexes (TpMe,Me)Mg(CH3), (TptBu,Me)Mg(CH3), and (TpMe,Me)Mg(AlMe4). The latter tetramethylaluminate complex can also be obtained by treatment of TpMe,MeMg(CH3) with an excess of trimethylaluminum. The formally six-coordinate cyclopentadienyl derivative (C5Me5)Mg(Me)(thf)2 is synthesized from MeMgBr and 1 equiv of K(C5Me5). Equimolar reactions of the tetraethylaluminates [M(AlEt4)2]n of the heavier alkaline-earth metals calcium and barium with KTpR,Me give the homoleptic complexes of Ca(TpR,Ph)2 and Ba(TpR,Me)2. Heterotrimetallic [BaK(AlEt4)3]n is identified as a liga...
- Published
- 2012
16. Uptake and elimination of florfenicol in Atlantic cod (Gadus morhua) larvae delivered orally through bioencapsulation in the brine shrimp Artemia franciscana
- Author
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Ole Bent Samuelsen, Irja Sunde Roiha, Amund Litlabø, and Erling Otterlei
- Subjects
Florfenicol ,Larva ,biology ,fungi ,Brine shrimp ,Aquatic Science ,biology.organism_classification ,High-performance liquid chromatography ,Fishery ,chemistry.chemical_compound ,Animal science ,chemistry ,Dry weight ,Oral administration ,Gadus ,Atlantic cod - Abstract
As an approach to combat bacterial infections, incorporation of florfenicol in Atlantic cod ( Gadus morhua ) larvae, administered orally through bioencapsulation in Artemia franciscana nauplii, was investigated. Artemia nauplii were enriched with 1000 mg/l florfenicol for 30 min and administered as a single dose, or daily for three consecutive days. The concentration of florfenicol in the medicated nauplii, and in the cod larvae, was analysed by high performance liquid chromatography (HPLC). Following a single oral administration, the elimination half-life ( t ½ β) was calculated to 14 h, C max to 4.7 μg/g dry weight (14.3 ng/larva), T max to 0.5 h, and MRT to 20 h, respectively. An hour after administration of batch 1 in the triple dose study, a mean florfenicol concentration of 4.6 μg/g dry weight (14.0 ng/larva) was found in the cod larvae. One hour following administration of batch 2 and 3, corresponding values were 5.9 μg/g dry weight (17.9 ng/larva) and 4.2 μg/g dry weight (12.8 ng/larva), respectively. These data show that medication of cod larvae using Artemia nauplii as carriers of florfenicol is a promising approach for treatment.
- Published
- 2010
17. Bis(tetramethylaluminate) Complexes of Yttrium and Lanthanum Supported by a Quinolyl-Substituted Cyclopentadienyl Ligand: Synthesis and Performance in Isoprene Polymerization
- Author
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Rannveig Litlabø, Reiner Anwander, Markus Enders, and Karl W. Törnroos
- Subjects
Chemistry ,Ligand ,Organic Chemistry ,Inorganic chemistry ,Substituent ,chemistry.chemical_element ,Medicinal chemistry ,Inorganic Chemistry ,chemistry.chemical_compound ,Cyclopentadienyl complex ,Polymerization ,Lanthanum ,Protonolysis ,Physical and Theoretical Chemistry ,Homoleptic ,Isoprene - Abstract
Quinolyl-substituted half-sandwich complexes (CpQ)Ln(AlMe4)2 (CpQ = 2,3,4,5-tetramethyl-1-(8-quinolyl)cyclopentadienyl; Ln = Y, La) were obtained in quantitative yield via protonolysis reactions utilizing HCpQ and homoleptic tetramethylaluminates Ln(AlMe4)3. X-ray structure analyses revealed that the quinolyl-substituted cyclopentadienyl ligand coordinates to the rare-earth metal centers in an η5:η1 fashion through the Cp ring carbon atoms and the N atom of the quinolyl substituent. The complexes (CpQ)Ln(AlMe4)2 show good activity and high trans-1,4-stereoselectivity (maximum 93%) in the polymerization of isoprene upon activation with the organoborates [Ph3C][B(C6F5)4] and [PhNMe2H][B(C6F5)4]. The effects of metal size, cocatalyst, temperature, and solvent were assessed in these polymerization reactions, and the performance of such N-donor-functionalized complexes was compared to that of (CpR)Ln(AlMe4)2 containing different types of nondonor-functionalized cyclopentadienyl ligands.
- Published
- 2010
18. 'Metastable' Lu(GaMe4)3 Reacts Like Masked [LuMe3]: Synthesis of an Unsolvated Lanthanide Dimethyl Complex
- Author
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Karl W. Törnroos, Rannveig Litlabø, Melanie Zimmermann, and Reiner Anwander
- Subjects
Lanthanide ,Organic Chemistry ,Inorganic chemistry ,Weak interaction ,Medicinal chemistry ,Methane ,Inorganic Chemistry ,chemistry.chemical_compound ,Elimination reaction ,Monomer ,chemistry ,Lewis acids and bases ,Physical and Theoretical Chemistry ,Homoleptic ,Trimethylgallium - Abstract
Homoleptic tetramethylgallate Lu(GaMe4)3 reacts selectively with superbulky (TptBu,Me)H according to a methane elimination reaction, affording the quantitative formation of monomeric base-free low-coordinate (TptBu,Me)LuMe2. Weak interaction of the strongly basic lanthanide methyl groups with the comparatively weak Lewis acid trimethylgallium in Lu(GaMe4)3 is indicated by their separation into [LuMe3]n and GaMe3 even at −35 °C.
- Published
- 2009
19. Monomeric Tetraalkylaluminates of Divalent Ytterbium Stabilized by a Bulky Tris(pyrazolyl)borate Ligand
- Author
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Reiner Anwander, Robert McDonald, Rannveig Litlabø, Kuburat Saliu, Michael J. Ferguson, and Josef Takats
- Subjects
chemistry.chemical_classification ,Tris ,Ytterbium ,Agostic interaction ,Ligand ,Organic Chemistry ,Inorganic chemistry ,chemistry.chemical_element ,Divalent ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,Monomer ,chemistry ,Physical and Theoretical Chemistry ,Methylene ,Boron - Abstract
Mononuclear heterobimetallic complexes (TptBu,Me)Yb(AlR4) (R = Me, Et) were obtained in high yields according to a silylamide elimination protocol employing (TptBu,Me)Yb[N(SiMe3)2] and AlR3. The solid-state structures revealed κ3-coordinated TptBu,Me ligands and η2-coordinated [AlR4] moieties, with additional Yb···H agostic interactions from the bridging methyl and methylene groups of the [AlR4] ligands. These agostic interactions however are not strong enough to maintain a rigid structure in solution. 1H NMR spectroscopy showed a highly fluxional ligand environment with only one set of signals for both TptBu,Me and [AlR4] ligands at temperatures down to −80 °C.
- Published
- 2009
20. Eine Seltenerdmetallvariante des Tebbe-Reagens
- Author
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Kuburat Saliu, Rannveig Litlabø, Karl W. Törnroos, Reiner Anwander, Melanie Zimmermann, and Josef Takats
- Subjects
Chemistry ,General Medicine - Published
- 2008
21. Ca . Branchiomonas cysticola, Ca . Piscichlamydia salmonis and Salmon Gill Pox Virus transmit horizontally in Atlantic salmon held in fresh water
- Author
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Wiik-Nielsen, J, primary, Gjessing, M, additional, Solheim, H T, additional, Litlabø, A, additional, Gjevre, A-G, additional, Kristoffersen, A B, additional, Powell, M D, additional, and Colquhoun, D J, additional
- Published
- 2017
- Full Text
- View/download PDF
22. Virus-like particles associated with heart and skeletal muscle inflammation (HSMI)
- Author
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Marius Karlsen, M. Devold, E. Isdal, Kuninori Watanabe, A Litlabø, and Are Nylund
- Subjects
animal diseases ,Salmo salar ,Fisheries ,Inflammation ,Aquatic Science ,Kidney ,Polymerase Chain Reaction ,Virus ,Fish Diseases ,Microscopy, Electron, Transmission ,Virus-like particle ,medicine ,Animals ,Salmo ,Muscle, Skeletal ,Infectious pancreatic necrosis virus ,Cells, Cultured ,Ecology, Evolution, Behavior and Systematics ,Salmonidae ,DNA Primers ,Myositis ,biology ,Virion ,Outbreak ,Skeletal muscle ,Epithelial Cells ,Heart ,Anatomy ,biology.organism_classification ,Virology ,Myocarditis ,medicine.anatomical_structure ,medicine.symptom - Abstract
The first cases of heart and skeletal muscle inflammation (HSMI), in Atlantic salmon Salmo salar were registered in 1999 in the Hitra/Frøya area of Norway. The disease has since spread south to Rogaland, i.e. the southernmost county with salmon farming in Norway. The disease outbreaks usually start 5 to 9 mo after release into seawater but may occur as early as 2 wk after sea release. The present study focuses on possible pathogens associated with HSMI. It was not possible to find any parasites or bacteria that could explain HSMI, and none of the well-known viruses (infectious salmon anaemia virus, Norwegian salmonid alphavirus, infectious pancreatic necrosis virus, Atlantic salmonid paramyxovirus) were consistently present. Use of transmission electron microscopy showed the presence of epitheliocystis agent in 3 of 4 farms included in this study, and several virus-like particles. Type I and Type II virus particles, previously described for salmon suffering from haemorrhagic smolt syndrome (HSS), and erythrocytic inclusion body syndrome (EIBS) virus were consistently present in salmon suffering from HSMI in all 4 farms included in this study. The 2 HSS viruses (Type I and Type II) were also cultured in Atlantic salmon kidney (ASK) cells from salmon suffering from HSMI. However, a causal relationship between the observed virus particles and HSMI remains to be demonstrated.
- Published
- 2006
23. Rare-Earth-Metal Methyl and Methylidene Complexes Stabilized by TpR,R′-Scorpionato Ligands─Size Matters
- Author
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Schädle, Dorothea, Litlabø, Rannveig, Meermann-Zimmermann, Melanie, Thim-Spöring, Renita, Schädle, Christoph, Maichle-Mössmer, Cäcilia, Törnroos, Karl W., and Anwander, Reiner
- Abstract
Homoleptic tetramethylaluminates Ln(AlMe4)3react with KTptBu,Me(TptBu,Me= tris(3-tBu-5-Me-pyrazolyl)borato) to yield rare-earth-metal methylidene complexes (TptBu,Me)Ln(μ3-CH2)[(μ-Me)AlMe2]2(Ln = La, Ce, Nd). The lanthanum reaction is prone to additional C–H- and B–N-bond activation, affording coproducts La[HB(pzMe,tBu)(pzCMe2,Me)2][(μ-CH2)(μ-Me)AlMe2]2and [La(μ-pztBu,Me)(AlMe4)2]2(pztBu,Me= 3-tBu-5-Me-pyrazolato). The protonolysis reaction of Ln(AlMe4)3and HpztBu,Meprovides more efficient access to [Ln(μ-pztBu,Me)(AlMe4)2]2(Ln = La, Nd). Treatment of Ln(AlMe4)3with KTpMe,Meled to methylidene complexes (TpMe,Me)Ln(μ3-CH2)[(μ-Me)AlMe2]2(Ln = Nd, Sm) or bis(tetramethylaluminate) complexes (TpMe,Me)Ln(AlMe4)2(Ln = Y, Lu). The neodymium reaction generated methine derivative (TpMe,Me)Nd[(μ4-CH)(AlMe2)2(μ-pz,Me,Me)][(μ-Me)AlMe2] as a minor coproduct. The reaction of Ln(GaMe4)3(Ln = Y, La, Ce, Nd, Sm, Ho) with HTptBu,Megave methylidene complexes (TptBu,Me)Ln(μ3-CH2)[(μ-Me)GaMe2]2(Ln = La, Ce, Nd, Sm) and alkyl complexes (TptBu,Me)LnMe[(μ-Me)GaMe3] (Ln = Y, Ho), while competing B–N bond activation reactions produced GaMe2[BH(Me)(μ-pztBu,Me)2] and (TptBu,Me)Ln(η2-pztBu,Me)[(μ-Me)GaMe3] (Ln = Y, Ho). The steric impact of the TpR,Meligands was examined by cone angle calculations. Rare-earth-metal methylidene complexes (TptBu,Me)Ln(μ3-CH2)[(μ-Me)EMe2]2(E = Al, Ga) successfully promote carbonyl methylenation reactions upon addition of ketone.
- Published
- 2024
- Full Text
- View/download PDF
24. Synthesis and stability of homoleptic metal(III) tetramethylaluminates
- Author
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H. Martin Dietrich, Giovanni Occhipinti, Vidar R. Jensen, Reiner Anwander, Christian Meermann, Rannveig Litlabø, Cäcilia Maichle-Mössmer, Karl W. Törnroos, and Florian Auras
- Subjects
Ionic radius ,Inorganic chemistry ,chemistry.chemical_element ,Ionic bonding ,General Chemistry ,Biochemistry ,Catalysis ,Electronegativity ,Metal ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,chemistry ,Transition metal ,visual_art ,Atom ,visual_art.visual_art_medium ,Scandium ,Homoleptic - Abstract
Whereas a number of homoleptic metal(III) tetramethylaluminates M(AlMe(4))(3) of the rare earth metals have proven accessible, the stability of these compounds varies strongly among the metals, with some even escaping preparation altogether. The differences in stability may seem puzzling given that this class of metals usually is considered to be relatively uniform with respect to properties. On the basis of quantum chemically obtained relative energies and atomic and molecular descriptors of homoleptic tris(tetramethylaluminate) and related compounds of rare earth metals, transition metals, p-block metals, and actinides, multivariate modeling has identified the importance of ionic metal-methylaluminate bonding and small steric repulsion between the methylaluminate ligands for obtaining stable homoleptic compounds. Low electronegativity and a sufficiently large ionic radius are thus essential properties for the central metal atom. Whereas scandium and many transition metals are too small and too electronegative for this task, all lanthanides and actinides covered in this study are predicted to give homoleptic compounds stable toward loss of trimethylaluminum, the expected main decomposition reaction. Three of the predicted lanthanide-based compounds Ln(AlMe(4))(3) (Ln = Ce, Tm, Yb) have been prepared and fully characterized in the present work, in addition to Ln(OCH(2)tBu)(3)(AlMe(3))(3) (Ln = Sc, Nd) and [Eu(AlEt(4))(2)](n). At ambient temperature, donor-free hexane solutions of Ln(AlMe(4))(3) of the Ln(3+)/Ln(2+) redox-active metal centers display enhanced reduction to [Ln(AlMe(4))(2)](n) with decreasing negative redox potential, in the order Eu ≫ Yb ≫ Sm. Whereas Eu(AlMe(4))(3) could not be identified, Yb(AlMe(4))(3) turned out to be isolable in low yield. All attempts to prepare the putative Sc(AlMe(4))(3), featuring the smallest rare earth metal center, failed.
- Published
- 2011
25. Det skjulte arbeidsmarkedet
- Author
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Johanssen, Bernt Andre Ø., Litlabø, Sigurd Bjelland, and Langeland, Lars Peder
- Subjects
Økad - Abstract
Vi har valgt å kalle denne oppgaven ”Det skjulte arbeidsmarkedet”, hvor vi ønsket å finne ut hvorfor bedrifter velger å rekruttere på det som vi har definert som “uformell rekruttering”. Dette er basert på et nasjonalt anslag som tilsier at av alle ledige stillinger som er på markedet, er det kun 30-40 % av disse som lyses ut offentlig, mens de resterende 60-70% tilsettes uten noen form for offentlig stillingsutlysning. I oppgaven har vi valgt å definere de 60-70 % som et “skjult” arbeidsmarked. For å finne mer ut om temaet begynte vi med innsamling av litteratur igjennom søk på internett, bibliotek og tidligere pensumbøker fra organisasjons- og personalfag. Vi har valgt å dele oppgaven inn i fem hovedkapitler. Første del av oppgaven omhandler det teoretiske grunnlaget, som er delt opp i nettverk, rekruttering, kompetanse og personalplanlegging. Etter presentasjon av teori forteller vi om metodene vi har brukt for å samle inn data, der vi presenterer den kvantitative metoden spørreskjema sammen med den kvalitative metoden intervju. I den tredje delen av oppgaven presenterer vi data vi har fått fra informantene igjennom intervju, mens i den fjerde delen analyserer vi innsamlet data opp mot den første teoridelen. Det femte og avsluttende kapittelet inneholder konklusjonen vår, samt en oppsummering omkring våre egne tanker og meninger om temaet. Utgangspunktet for oppgaven vår var å finne ut hvorfor så mange bedrifter velger å rekruttere via en uformell metode. Igjennom vår forskning har vi ikke fått frem tydelige nok data til å kunne trekke en fast konklusjon på hvorfor dette er tilfellet. Vi har samtidig fått frem en del gode og kritiske blikk på denne rekrutteringsmetoden via våre informanter, som kan oppfordre til videre forskning. Eksempel på synspunktene rettet mot denne rekrutteringsmetoden er at noen informanter rekrutterte uformelt på grunn av høye kostnader ved en formell rekrutteringsprosess. Videre kunne dette også gjelde kostnader og risiko knyttet til en eventuell feilansettelse ved en formell prosess. Dette var basert på tidligere erfaring ved at en person hadde gitt seg ut for å være noe helt annet på søknad, CV og intervju enn det han egentlig var. Noen informanter mente samtidig at uformell rekruttering ble brukt basert ut i fra tidligere erfaringer og tradisjoner, mens andre informanter mente at dette var en tilfeldighet.
- Published
- 2011
26. A rare-earth metal variant of the Tebbe reagent
- Author
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Reiner Anwander, Josef Takats, Karl W. Törnroos, Kuburat Saliu, Melanie Zimmermann, and Rannveig Litlabø
- Subjects
Lanthanide ,Metal ,Chemistry ,Reagent ,visual_art ,Rare earth ,Inorganic chemistry ,visual_art.visual_art_medium ,General Chemistry ,Catalysis - Published
- 2008
27. Tris(pyrazolyl)borate Complexes of the Alkaline-Earth Metals: Alkylaluminate Precursors and Schlenk-Type Rearrangements
- Author
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Michel, Olaf, primary, Dietrich, H. Martin, additional, Litlabø, Rannveig, additional, Törnroos, Karl W., additional, Maichle-Mössmer, Cäcilia, additional, and Anwander, Reiner, additional
- Published
- 2012
- Full Text
- View/download PDF
28. Synthesis and Stability of Homoleptic Metal(III) Tetramethylaluminates
- Author
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Occhipinti, Giovanni, primary, Meermann, Christian, additional, Dietrich, H. Martin, additional, Litlabø, Rannveig, additional, Auras, Florian, additional, Törnroos, Karl W., additional, Maichle-Mössmer, Cäcilia, additional, Jensen, Vidar R., additional, and Anwander, Reiner, additional
- Published
- 2011
- Full Text
- View/download PDF
29. Bis(tetramethylaluminate) Complexes of Yttrium and Lanthanum Supported by a Quinolyl-Substituted Cyclopentadienyl Ligand: Synthesis and Performance in Isoprene Polymerization
- Author
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Litlabø, Rannveig, primary, Enders, Markus, additional, Törnroos, Karl W., additional, and Anwander, Reiner, additional
- Published
- 2010
- Full Text
- View/download PDF
30. Rare-earth metal bis(tetramethylaluminate) complexes supported by a sterically crowded triazenido ligand
- Author
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Litlabø, Rannveig, primary, Lee, Hyui Sul, additional, Niemeyer, Mark, additional, Törnroos, Karl W., additional, and Anwander, Reiner, additional
- Published
- 2010
- Full Text
- View/download PDF
31. “Metastable” Lu(GaMe4)3 Reacts Like Masked [LuMe3]: Synthesis of an Unsolvated Lanthanide Dimethyl Complex
- Author
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Zimmermann, Melanie, primary, Litlabø, Rannveig, additional, Törnroos, Karl W., additional, and Anwander, Reiner, additional
- Published
- 2009
- Full Text
- View/download PDF
32. Monomeric Tetraalkylaluminates of Divalent Ytterbium Stabilized by a Bulky Tris(pyrazolyl)borate Ligand
- Author
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Litlabø, Rannveig, primary, Saliu, Kuburat, additional, Ferguson, Michael J., additional, McDonald, Robert, additional, Takats, Josef, additional, and Anwander, Reiner, additional
- Published
- 2009
- Full Text
- View/download PDF
33. Rare-earth metal bis(tetramethylaluminate) complexes supported by a sterically crowded triazenido ligand
- Author
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Rannveig Litlabø, Hyui Sul Lee, Reiner Anwander, Karl W. Törnroos, and Mark Niemeyer
- Subjects
Steric effects ,Chemistry ,Ligand ,Stereochemistry ,Medicinal chemistry ,Inorganic Chemistry ,Metal ,chemistry.chemical_compound ,visual_art ,visual_art.visual_art_medium ,Salt metathesis reaction ,Redistribution (chemistry) ,Protonolysis ,Isostructural ,Homoleptic - Abstract
Complexes [NNN]Ln(AlMe(4))(2) (Ln = Y, La, Nd, Lu) bearing the sterically demanding aryl-substituted triazenido ligand [(Tph)(2)N(3)] (Tph = [2-(2,4,6-iPr(3)C(6)H(2))C(6)H(4)]) can be obtained from homoleptic complexes Ln(AlMe(4))(3) in moderate yields, both via protonolysis with [(Tph)(2)N(3)]H and a salt metathesis reaction pathway utilizing [(Tph)(2)N(3)]K. In the solid state the Y and Lu derivatives are isostructural, with both tetramethylaluminate groups coordinated in an eta(2) fashion, while one of the [AlMe(4)] ligands of the Nd derivative features a distorted eta(2) coordination mode. Due to the high affinity of the triazenido ligand toward the more Lewis-acidic and harder aluminium cation compared to the softer rare-earth metal centres, ligand redistribution is observed in solution and formation of byproduct [(Tph)(2)N(3)]AlMe(2) is prominent. While the monoanionic triazenido ligand coordinates the rare-earth metal centres in an asymmetrical syn/anti fashion, it adopts an almost symmetric syn/syn configuration in the aluminium complex. Attempts were also made to produce putative dimethyl complexes {[(Tph)(2)N(3)]LnMe(2)} (Ln = Y, Lu) via cleavage of the aluminate moieties with diethyl ether. Furthermore, the intrinsic redistribution reactions are proposed to affect the performance of complexes [(Tph)(2)N(3)]Ln(AlMe(4))(2) in isoprene polymerization.
- Published
- 2010
34. Eine Seltenerdmetallvariante des Tebbe-Reagens
- Author
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Litlabø, Rannveig, primary, Zimmermann, Melanie, additional, Saliu, Kuburat, additional, Takats, Josef, additional, Törnroos, Karl W., additional, and Anwander, Reiner, additional
- Published
- 2008
- Full Text
- View/download PDF
35. A Rare‐Earth Metal Variant of the Tebbe Reagent
- Author
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Litlabø, Rannveig, primary, Zimmermann, Melanie, additional, Saliu, Kuburat, additional, Takats, Josef, additional, Törnroos, Karl W., additional, and Anwander, Reiner, additional
- Published
- 2008
- Full Text
- View/download PDF
36. Virus-like particles associated with heart and skeletal muscle inflammation (HSMI)
- Author
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Watanabe, K, primary, Karlsen, M, additional, Devold, M, additional, Isdal, E, additional, Litlabø, A, additional, and Nylund, A, additional
- Published
- 2006
- Full Text
- View/download PDF
37. Tris(pyrazolyl)borateComplexes of the Alkaline-EarthMetals: Alkylaluminate Precursors and Schlenk-Type Rearrangements.
- Author
-
Michel, Olaf, Dietrich, H. Martin, Litlabø, Rannveig, Törnroos, Karl W., Maichle-Mössmer, Cäcilia, and Anwander, Reiner
- Published
- 2012
- Full Text
- View/download PDF
38. “Metastable” Lu(GaMe4)3Reacts Like Masked [LuMe3]: Synthesis of an Unsolvated Lanthanide Dimethyl Complex.
- Author
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Melanie Zimmermann, Rannveig Litlabø, Karl W. Törnroos, and Reiner Anwander
- Subjects
- *
COMPLEX compounds synthesis , *ORGANORARE earth metal compounds , *METAL complexes , *GALLATES , *METHANE , *ELIMINATION reactions , *MONOMERS , *LEWIS acids - Abstract
Homoleptic tetramethylgallate Lu(GaMe4)3reacts selectively with superbulky (TptBu,Me)H according to a methane elimination reaction, affording the quantitative formation of monomeric base-free low-coordinate (TptBu,Me)LuMe2. Weak interaction of the strongly basic lanthanide methyl groups with the comparatively weak Lewis acid trimethylgallium in Lu(GaMe4)3is indicated by their separation into [LuMe3]nand GaMe3even at −35 °C. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
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