Oxygen excess in layered lanthanide nickelates

Density measurements on large single-crystal specimens of La2NiO4+δ and Pr2NiO4+δ show that oxygen nonstoichiometry arises from the presence of excess lattice oxygen. X-ray photoelectron spectra as well as X-ray absorption edge studies provide no evidence for the existence of Ni3+ in these oxygen-excess nickelates under the conditions of the measurements. Transmission electron microscopy has revealed a novel type of exsolution process of the stoichiometric phase out of nonstoichiometric La2NiO4 during heating in CO2 at 870 K for 3 h. An interpretation of the results in terms of the existence of peroxide species within the conducting layers is proposed.

Reactions of bis(isonitrosoethylacetoacetato)palladium(II) with straight chain aliphatic primary amines influence of concentration of the reacting amines on the nature of the products

Reactions of bis(isonitrosoethylacetoacetato)palladium(II), Pd(IEAA)2,with straight chain non-bulky alkylamines, RNH2(R = CH3, C2H5, n-C3H7or n-C4H9) in the mole ratio 1:1 gave bis (B-alkylisonitrosoethylacetoacetateimino)Palladium(II), Pd(R-IEAI)2. In this reaction the coordinated carbonyl groups of Pd(IEAA)2 undergo condensation with amines fo rming Schiff bases (>CNR). On the other hand, the reactions of Pd(IEAA)2 with a large excess of amine yielded N-alkylamido bridgedisonitrosoethylacetoacetatedipalladium(II), μ-(NHR)2[Pd(IEAA)]2 complexes. The complexes are characterized by elemental analyses, magnetic susceptib ility, i.r., p.m.r. and in some cases, nitrogen 1s X-ray photoelectron and mass spectral studies.

Interaction of nitrogen with fullerenes: nitrogen derivatives of C60 and C70

On the basis of N(1s) core-level spectroscopic studies, it is found that nitrogen interacts with multimolecular films of C60. More interestingly, mass spectrometric studies show that contact-arc vaporization of graphite in a partial atmosphere of N2 or NH3 yields nitrogenous products tentatively assigned to species such as C70N2, C59N6, C59N4, and C59N2 involving addition of or substitution by nitrogen along with the species due to C2 and C4 losses.

Nature of nitrogen adsorbed on transition metal surfaces as revealed by electron spectroscopy and cognate techniques

The nature of the chemisorbed states of nitrogen on various transition metal surfaces is discussed comprehensively on the basis of the results of electron spectroscopic investigations augmented by those from other techniques such as LEED and thermal desorption. A brief discussion of the photoemission spectra of free N2, a comparison of adsorbed N2 and CO as well as of physisorption of N2 on metal surfaces is also presented. We discuss the chemisorption of N2 on the surfaces of certain metals (e.g. Ni, Fe, Ru and W) in some detail, paying considerable attention to the effect of electropositive and electronegative surface modifiers. Features of the various chemisorbed states (one or more weakly chemisorbed gamma-states, strongly chemisorbed alpha-states with bond orders between 1 and 2. and dissociative chemisorbed beta-states) on different surfaces are described and relations between them indicated. While the gamma-state could be a precursor of the alpha-state, the alpha-state could be the precursor of the beta-state and this kind of information is of direct relevance to ammonia synthesis. The nature of adsorption of N2 on the surfaces of some metals (e.g. Cr, Co) deserves further study and such investigations might as well suggest alternative catalysts for ammonia synthesis.

Oxidation of Quinolinols - Synthesis of Spirodienones Containing Nitrogen

Reaction of 6-quinolinol with formaldehyde and sodium sulphite gives the bisquinolinol (1b). Similar reaction of 6-quinolinol with sodium 2-hydroxy1-naphthylmethanesulphonate gives 1c. Oxidation of 1b with K3Fe(CN)6 or KOBr gives the spiroquinolinone 2b, while oxidation of 1c with K3Fe(CN)6 results in the formation of spirodienones 2c and 2d, and the dispiroketones 7b and 7c. Oxidation of 1c with DDQ, however, results in only the spirodienones 2c and 2d. The spirodienone 2d and the bromospiroquinolinone 2e are formed in the reaction of 1c with KOBr.

Use of wetland buffer areas to reduce nitrogen transport from forested catchments: Retention capacity, emissions of N2O and CH4 and vegetation composition dynamics

The use of buffer areas in forested catchments has been actively researched during the last 15 years; but until now, the research has mainly concentrated on the reduction of sediment and phosphorus loads, instead of nitrogen (N). The aim of this thesis was to examine the use of wetland buffer areas to reduce the nitrogen transport in forested catchments and to investigate the environmental impacts involved in their use. Besides the retention capacity, particular attention was paid to the main factors contributing to the N retention, the potential for increased N2O emissions after large N loading, the effects of peatland restoration for use as buffer areas on CH4 emissions, as well as the vegetation composition dynamics induced by the use of peatlands as buffer areas. To study the capacity of buffer areas to reduce N transport in forested catchments, we first used large artificial loadings of N, and then studied the capacity of buffer areas to reduce ammonium (NH4-N) export originating from ditch network maintenance areas in forested catchments. The potential for increased N2O emissions were studied using the closed chamber technique and a large artificial N loading at five buffer areas. Sampling for CH4 emissions and methane-cycling microbial populations were done on three restored buffer areas and on three buffers constructed on natural peatlands. Vegetation composition dynamics was studied at three buffer areas between 1996 and 2009. Wetland buffer areas were efficient in retaining inorganic N from inflow. The key factors contributing to the retention were the size and the length of the buffer, the hydrological loading and the rate of nutrient loading. Our results show that although the N2O emissions may increase temporarily to very high levels after a large N loading into the buffer area, the buffer areas in forested catchments should be viewed as insignificant sources of N2O. CH4 fluxes were substantially higher from buffers constructed on natural peatlands than from the restored buffer areas, probably because of the slow recovery of methanogens after restoration. The use of peatlands as buffer areas was followed by clear changes in plant species composition and the largest changes occurred in the upstream parts of the buffer areas and the wet lawn-level surfaces, where the contact between the vegetation and the through-flow waters was closer than for the downstream parts and dry hummock sites. The changes in the plant species composition may be an undesired phenomenon especially in the case of the mires representing endangered mire site types, and therefore the construction of new buffer areas should be primarily directed into drained peatland areas.

An electron spectroscopic study of the adsorption of nitrogen on a Ni/TiO2 catalyst prepared in situ in the spectrometer: evidence for dissociative adsorption in the strong-metal-support-interaction (SMSI) state

Nitrogen is dissociatively adsorbed on an annealed Ni/TiO2 surface just as on a Ti–Ni alloy surface while it is molecularly adsorbed on a Ni/Al2O3 surface.

A Photoelectron Spectroscopic Study Of The Interaction Of Oxygen, Nitrogen And Transition-Metals With C-60 Films

Evidence is presented for the strong interaction of oxygen and nitrogen with solid films of buckminsterfullerene based on core-level spectroscopic studies. Cr, Ni and Cu deposited on C60 films interact strongly giving rise to large changes in the C(Is) and C(2p) binding energies as well as the (2p) binding energies of the transition metals.

Mykorritsa fosforin kierrättäjänä

Suomen maatalousmaihin kertynyttä fosforia hyödynnetään tehottomasti, ja samalla muokkauskerroksen suuri fosforimäärä on alttiina huuhtoutumiselle. Arbuskelimykorritsaa (AM) hyödyntämällä on mahdollista tehostaa viljelykasvin fosforinottoa ja kasvua, ja siten vähentää fosforin huuhtoutumista. Tämän tutkielman tavoitteena oli selvittää mykorritsan vaikutus kasvin kasvuun ja fosforinottoon karjanlantalannoituksella mineraalilannoitukseen verrattuna sekä näiden lannoitusten pitkäaikaisvaikutusta AM-sieniyhteisöihin. Jotta lannoituskäytäntöjen vaikutus mykorritsaan voitiin suhteuttaa muihin maan laatutekijöihin, näiden käytäntöjen vaikutus myös satomääriin sekä muihin maan laatumittareihin arvioitiin. Pitkäaikainen kenttäkoe perustettiin kolmelle paikkakunnalle Pohjois-Ruotsissa vuosina 1965–66. Kuusivuotinen viljelykierto koostui joko viisivuotisesta nurmesta ja ohrasta tai ohramonokulttuurista. Lannoituskäsittelyt 32-vuoden ajan olivat suositusten mukainen (NPK) ja edelliseen nähden kaksinkertainen (2NPK) mineraalilannoitus sekä karjanlantalannoitus (KL), jonka ravinnemäärä vastasi NPK -käsittelyä. Kolmen lannoituskäsittelyn vaikutusta mykorritsan tehokkuuteen kasvin kasvun ja fosforiravitsemuksen näkökulmasta tutkittiin astiakokeissa. Mykorritsasieniyhteisöjen toiminnallisten erojen selvittämiseksi tehtiin takaisin- ja ristiinsiirrostuskoe. (5 v-%) steriloitua maanäytettä NPK- ja KL -käsittelyistä siirrostettiin käsittelemättömiin maanäytteisiin, jotka olivat samoista lannoituskäsittelyistä. Mykorritsan positiivinen vaikutus kasvin kasvuun ja fosforiravitsemukseen oli suurin kun käytettiin karjanlantaa. NPK ja 2NPK -käsittelyiden välillä ei havaittu eroja. Takaisin- ja ristiinsiirrostuskokeessa ei ollut tilastollisesti merkitseviä eroja. Nurmi- ja ohrasadot olivat suurimmat kun mineraalilannoitetta annettiin suosituksiin nähden kaksinkertainen määrä. Satomäärät olivat yhtä suuret tai suuremmat kun käytettiin karjanlantaa NPK –lannoituksen sijaan. Karjanlantakäsittely lisäsi maaperän kokonaishiili- ja kokonaistyppipitoisuutta verrattuna NPK -käsittelyyn, joka sisälsi saman määrän ravinteita. Samalla huuhtoutumiselle altis liukoisen fosforin pitoisuus säilyi alhaisella tasolla. Karjanlanta edisti mykorritsan toimintaedellytyksiä, ja siksi mykorritsasta saatua hyötyä fosforinotossa ja kasvuvaikutuksena mineraalilannoitteisiin verrattuna, mutta se ei vaikuttanut mykorritsasieniyhteisön toiminnallisiin ominaisuuksiin. Karjanlantalannoitus paransi mitattuja maan ominaisuuksia kokonaisuudessaan, eikä se vähentänyt satoja.

Long-Term Excess Mortality after Aneurysmal Subarachnoid Hemorrhage

Objective There is high case-fatality rate and loss of productive life-years related to aneurysmal subarachnoid hemorrhage (aSAH) but little data on long-term survival of SAH patients. We aim to evaluate long-term excess mortality and related risk factors after aSAH. Methods One year survivors (n=3080) after aSAH from Department of Neurosurgery in Helsinki between 1980 and 2007 were reviewed for this retrospective follow-up study. Follow-up started one year after SAH and continued until death or the end of 2008 (36 960 patient-years). Mortality and relative survival ratio (RSR) were compared with matched general population. Results After 20 years, survivors of aSAH showed 18% excess mortality compared to general population. Risk factors included: old age; poor preoperative clinical condition; conservative aneurysm treatment; multiple aneurysms; and unfavourable clinical outcome at 3 months. Conclusion Even after initially favourable recovery, patients with aSAH experience excess mortality in the long run. Cardiovascular and cerebrovascular diseases are prominent in this population.

Effect of drainage basin characteristics on the diffuse load of phosphorus and nitrogen.

Tiivistelmä: Valuma-alueen vaikutus fosforin ja typen hajakuormitukseen.

Metal-Insulator Transitions in Anion-Excess LaMnO3+? Controlled by the Mn4+ Content

LaMnO3+? samples with Mn4+ content up to 50% have been prepared by different methods. The structure of LaMnO3+? changes from orthorhombic to cubic (via rhombohedral) with increase in the Mn4+ content. LaMnO3+? samples containing greater than 20% Mn4+ are ferromagnetic and show resistivity maxima at a temperature Tt which is close to the ferromagnetic Curie temperature. The resistivity maximum is due to the occurrence of a metal-insulator transition. In samples heated to the same temperature, the value of Tt increases with % Mn4+. For a given sample, Tt increases with the temperature of heat treatment due to the increase in particle size. The onset of ferromagnetism in LaMnO3+? accompanied by an insulator-metal transition is similar to that found in La1-xCaxMnO3 and La1-xSrxCoO3.

Quantification of enantiomeric excess by H-1-detected heteronuclear refocusing and homonuclear multiple quantum NMR experiments

The omega(1)-heterodecoupled-C-13-filtered proton detected NMR experiments are reported for the accurate quantification of enantiomeric excess in chiral molecules embedded in chiral liquid crystal. The differential values of both H-1-H-1 and C-13-H-1 dipolar couplings in the direct dimension and only H-1-H-1 dipolar couplings in the indirect dimension enable unraveling of overlapped enantiomeric peaks. The creation of unequal C-13-bound proton signal for each enantiomer in the INEPT block and non-uniform excitation of coherences in homonuclear multiple quantum experiments do not yield accurate quantification of enantiomeric excess. In circumventing these difficulties, a coupling dependent intensity correction factor has been invoked. (C) 2010 Elsevier B.V. All rights reserved.

1H-4,1,2-Benzothiadiazines from 1,2,3-Benzothiadiazole via Alkylbenzothiadiazolium Salts: A Novel Heterocyclic Ring Expansion Possibly via Nitrogen Ylides.

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