Log in

Relevant bibliographies by topics / Iron oxalate

Contents

Journal articles
Dissertations / Theses
Book chapters
Conference papers

Academic literature on the topic 'Iron oxalate'

Author: Grafiati

Published: 4 June 2021

Last updated: 5 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Iron oxalate.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Iron oxalate"

1

Niskanen, Raina. "Extractable aluminium, iron and manganese in mineral soils: II Extractability by oxalate and pyrophosphate." Agricultural and Food Science 61, no. 2 (March 1, 1989): 79–87. http://dx.doi.org/10.23986/afsci.72356.

Full text

Abstract:

The extractability of aluminium, iron and manganese by 0.05 M oxalate and pyrophosphate was studied in samples of 23 mineral soils. Dilute extractants were studied because conventional reagents may cause problems in analytical work. The mean values for Al, Fe and Mn extracted by conventional Tamm’s oxalate were 67, 81 and 1.5 mmol/kg soil, respectively. On the average, 0.05 M oxalate solutions at pH 2.9 and 4.2 extracted Al, Fe and Mn amounts that were 103, 113 and 87 % and 72, 82 and 83 % of the amounts extractable by Tamm’s oxalate, respectively. Eeach metal released by 0.05 M oxalates correlated closely with that dissolved by Tamm’s oxalate; the r values ranged from 0.967*** to 0.997***. The mean values for Al, Fe and Mn extracted by 0.1 M Na4P2O7 and 0.05 M K4P2O7 were 38, 28 and 0.6 and 33, 29 and 0.6 mmol/kg soil, respectively. The amount of each metal extracted by Na4P2O7 correlated closely with that released by K4P2O7; the r values ranged from 0.87*** to 0.97***.

APA, Harvard, Vancouver, ISO, and other styles

2

Diefallah, El-H. M., M. A. Mousa, A. A. El-Bellihi, E. H. El-Mossalamy, G. A. El-Sayed, and M. A. Gabal. "Thermal decomposition of iron(II) oxalate–magnesium oxalate mixtures." Journal of Analytical and Applied Pyrolysis 62, no. 2 (February 2002): 205–14. http://dx.doi.org/10.1016/s0165-2370(01)00117-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Basahel, S. N., A. A. El-Bellihi, M. Gabal, and El-H. M. Diefallah. "Thermal decomposition of iron(III) oxalate-magnesium oxalate mixtures." Thermochimica Acta 256, no. 2 (June 1995): 339–46. http://dx.doi.org/10.1016/0040-6031(94)02158-k.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Benhacine, Mohamed Al Amine, Malika Hamadène, Sofiane Bouacida, and Hocine Merazig. "The new one-dimensional coordination polymercatena-poly[[diaquasodium(I)]-μ-oxalato-[diaquairon(III)]-μ-oxalato]." Acta Crystallographica Section C Structural Chemistry 72, no. 3 (February 29, 2016): 243–50. http://dx.doi.org/10.1107/s2053229616002953.

Full text

Abstract:

The oxalate dianion is one of the most studied ligands and is capable of bridging two or more metal centres and creating inorganic polymers based on the assembly of metal polyhedra with a wide variety of one-, two- or three-dimensional extended structures. Yellow single crystals of a new mixed-metal oxalate, namelycatena-poly[[diaquasodium(I)]-μ-oxalato-κ4O1,O2:O1′,O2′-[diaquairon(III)]-μ-oxalato-κ4O1,O2:O1′,O2′], [NaFe(C2O4)2(H2O)4]n, have been synthesized and the crystal structure elucidated by X-ray diffraction analysis. The compound crystallizes in the noncentrosymmetric space groupI41(Z= 4). The asymmetric unit contains one NaIand one FeIIIatom lying on a fourfold symmetry axis, one μ2-bridging oxalate ligand and two aqua ligands. Each metal atom is surrounded by two chelating oxalate ligands and two equivalent water molecules. The structure consists of infinite one-dimensional chains of alternating FeO4(H2OW1)2and NaO4(H2OW2)2octahedra, bridged by oxalate ligands, parallel to the [100] and [010] directions, respectively. Because of thecisconfiguration and the μ2-coordination mode of the oxalate ligands, the chains run in a zigzag manner. This arrangement facilitates the formation of hydrogen bonds between neighbouring chains involving the H2O and oxalate ligands, leading to a two-dimensional framework. The structure of this new one-dimensional coordination polymer is shown to be unique among theAIMIII(C2O4)2(H2O)nseries. In addition, the absorption bands in the IR and UV–Visible regions and their assignments are in good agreement with the local symmetry of the oxalate ligand and the irregular environment of iron(III). The final product of the thermal decomposition of this precursor is the well-known ternary oxide NaFeO2.

APA, Harvard, Vancouver, ISO, and other styles

5

Gabal, M. A., A. A. El-Bellihi, and H. H. El-Bahnasawy. "Non-isothermal decomposition of zinc oxalate–iron(II) oxalate mixture." Materials Chemistry and Physics 81, no. 1 (July 2003): 174–82. http://dx.doi.org/10.1016/s0254-0584(03)00183-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Gismonti, Pedro Rosário, Jéssica Frontino Paulino, and Julio Afonso. "RECOVERY OF METALS FROM ELECTROACTIVE COMPONENTS OF SPENT Ni-MH BATTERIES AFTER LEACHING WITH FORMIC ACID." Detritus, no. 14 (March 31, 2021): 68–77. http://dx.doi.org/10.31025/2611-4135/2021.14063.

Full text

Abstract:

this work describes a route for recovering nickel, cobalt, iron, zinc and lanthanides from spent nickel-metal hydride batteries. Formic acid was used as leachant. Experiments were run at 25-50°C for 1-4 h. Under the best conditions leaching yields surpassed 99 wt.%, except for iron. The insoluble matter contains almost solely iron as iron(III) basic formate. The leachate went through six separation procedures, combining solvent extraction with D2EHPA as extractant, and precipitation reactions. Fe2+ and Zn2+ were extracted together (> 99 wt.%) from the original leachate (pH ~1.5). Yttrium and lanthanides were precipitated as oxalates directly from the raffinate (> 99.9 wt.%) upon addition of sodium oxalate. In the next steps, Mn2+ and Co2+ were extracted with D2EHPA at buffered pH (3 and ~4.8, respectively), after adding NaOHaq. About 10 wt.% of leached Ni2+ was coextracted with Co2+. The remaining Ni2+ was precipitated from the raffinate after addition of aqueous sodium oxalate at pH 6. After precipitation of Al3+ upon addition of NaOHaq. until pH ~8, sodium formate was recovered after slow evaporation of the final aqueous solution at 60oC. It contains ~90 wt.% of the formate present in the leachant.

APA, Harvard, Vancouver, ISO, and other styles

7

Niskanen, Raina. "Release of phosphorus, aluminium and iron in fractionation of inorganic soil phosphorus." Agricultural and Food Science 59, no. 2 (April 1, 1987): 141–45. http://dx.doi.org/10.23986/afsci.72256.

Full text

Abstract:

Release of phosphorus, aluminium and iron by a modified Chang and Jackson procedure was studied in five mineral soils. Quantities of aluminium and iron released during the procedure and extracted by acid ammonium oxalate were compared. The extractability of P, Al and Fe by 1 M NH4CI and that of Al and Fe by alkaline 0.5 M NH4F was poor. Proportions of P extracted by 0.5 M NH4F (0.2—10.4 mmol/kg soil) and 0.1 M NaOH (0.1— 9.8 mmol/kg soil) were related to the molar ratio of oxalate-extractable iron and aluminium. P extracted by 0.25 M H2SO4 amounted to 2.1—12.2 mmol/kg soil. Al extracted by 0.1 M NaOH (7—174 mmol/kg soil) and 0.25 M H2SO4 (17—112 mmol/kg soil) amounted to 55—94 % and 16—245 % of oxalate-extractable Al, respectively. Fe released by 0.1 M NaOH (1—10 mmol/kg soil) and 0.25 M H2SO4 (30—196 mmol/kg soil) amounted to 1—13 % and 62—272 % of oxalate-extractable Fe, respectively. In total, 91—309 % of oxalate-extractable Al and 70—285 % of oxalate-extractable Fe were released by NaOH and H2SO4.

APA, Harvard, Vancouver, ISO, and other styles

8

Paris, R., and K. V. Desboeufs. "Effect of atmospheric organic complexation on iron-bearing dust solubility." Atmospheric Chemistry and Physics Discussions 13, no. 2 (February 4, 2013): 3179–202. http://dx.doi.org/10.5194/acpd-13-3179-2013.

Full text

Abstract:

Abstract. Recent studies reported that the effect of organic complexation may be a potentially important process to be considered in models to estimate atmospheric iron flux to the ocean. In this study, we investigated this effect by a series of dissolution experiments on iron-bearing dust in presence or absence of various organic compounds typically found in the atmospheric waters (acetate, formate, oxalate, malonate, succinate, glutarate, glycolate, lactate, tartrate and humic acid as an analogue of humic like substances (HULIS)). Only 4 of tested organic ligands (oxalate, malonate, tartrate and humic acid) caused an enhancement of iron solubility which was associated with an increase of dissolved Fe(II) concentrations. For all of these organic ligands, a positive linear dependence of iron solubility to organic concentrations was observed and showed that the extent of organic complexation on iron solubility decreased in order oxalate > malonate = tartrate > humic acid. This was attributed to the ability of electron donors of organic ligands and implied a reductive ligand-promoted dissolution. This study confirmed that oxalate is the most effective ligand playing on dust iron solubility and showed, for the first time, the potential effect of HULIS on iron dissolution in atmospheric conditions.

APA, Harvard, Vancouver, ISO, and other styles

9

Piro, O. E., G. A. Echeverría, and E. J. Baran. "Spontaneous enantiomorphism in poly-phased alkaline salts of tris(oxalato)ferrate(III): crystal structure of cubic NaRb5[Fe(C2O4)3]2." Acta Crystallographica Section E Crystallographic Communications 74, no. 7 (June 8, 2018): 905–9. http://dx.doi.org/10.1107/s2056989018008022.

Full text

Abstract:

We show here that the phenomenon of spontaneous resolution of enantiomers occurs during the crystallization of the sodium and rubidium double salts of the transition metal complex tris(oxalato)ferrate(III), namely sodium pentarubidium bis[tris(oxalato)ferrate(III)], NaRb5[Fe(C2O4)3]2. One enantiomer of the salt crystallizes in the cubic space groupP4332 withZ= 4 and a Flack absolute structure parameterx= −0.01 (1) and its chiral counterpart in the space groupP4132 withx= −0.00 (1). All metal ions are at crystallographic special positions: the iron(III) ion is on a threefold axis, coordinated by three oxalate dianions in a propeller-like conformation. One of the two independent rubidium ions is on a twofold axis in an eightfold coordination with neighbouring oxalate oxygen atoms, and the other one on a threefold axis in a sixfold RbO6coordination. The sodium ion is at a site ofD3point group symmetry in a trigonal–antiprismatic NaO6coordination.

APA, Harvard, Vancouver, ISO, and other styles

10

Luo, Chao, and Yuan Gao. "Aeolian iron mobilisation by dust - acid interactions and their implications for soluble iron deposition to the ocean: a test involving potential anthropogenic organic acidic species." Environmental Chemistry 7, no. 2 (2010): 153. http://dx.doi.org/10.1071/en09116.

Full text

Abstract:

Environmental context. Studying the input of atmospheric soluble iron to the ocean is important as the soluble form of iron is bioavailable for phytoplankton uptake in the surface ocean to support photosynthesis. In this paper, the effect of organic acidic species on atmospheric iron dissolution is addressed through a global model for the first time. The new results contribute to a better understanding of iron dissolution processes in the atmosphere and the role of atmospheric iron in ocean biogeochemical cycles. Abstract. Dust deposition is a major source of iron in certain oceanic regions. Many atmospheric processes, such as heterogeneous reactions with acidic species, may convert insoluble iron in dust to soluble forms that become bioavailable for phytoplankton uptake in the surface ocean. Here we report for the first time the effects of organic acidic species on iron dissolution using laboratory-measured conversion rates by oxalate, simulated in a global model to estimate soluble iron fluxes to the ocean. With the complexity and limited data from measurements relating to different sources for oxalate, we focus on the effect of oxalate of anthropogenic origin in this work as a first-step testing, and we apply a scaling factor for oxalate based on its relationship with aerosol sulfate observed by in situ measurements in the continental sites. The results show better correlation with the observations than the work including inorganic acids alone, suggesting the contribution of organic acids to Fe dissolution. However, the simulated iron solubility is lower than that derived from measurements, suggesting additional processes may contribute to Fe dissolution that should be included in the model. Total deposition of soluble iron to the global ocean including the effect by anthropogenic oxalate is ~0.34 Tg year–1.

APA, Harvard, Vancouver, ISO, and other styles

More sources

Dissertations / Theses on the topic "Iron oxalate"

1

Teer, Joseph Edward. "A study of the biodegradation of modelled iron oxalate leach liquors in an upflow anaerobic sludge blanket (UASB) reactor." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309306.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Wolter, Roberto Carlos Doring. "Prognóstico da toxidez de ferro em arroz irrigado por alagamento através da análise de solo pelo método oxalato de amônio." Universidade Federal de Pelotas, 2010. http://repositorio.ufpel.edu.br/handle/ri/1184.

Full text

Abstract:

Made available in DSpace on 2014-08-20T13:25:43Z (GMT). No. of bitstreams: 1 Dissertacao_Roberto_ Carlos_Doring_ Wolter.pdf: 973904 bytes, checksum: 67cf8c20b65c6a70b13833df022a0d9c (MD5) Previous issue date: 2010-03-05
Iron toxicity can cause considerable reductions in the productivity of rice, depending on the severity of symptoms and the affected area in the field. It is necessary to identify the factors that determine the occurrence of this nutritional disorder, so that effective measures may be carried out to correct this problem in the field. The objective of this study is to verify that the interpretation criteria for prognosis of the risk of iron toxicity in flooded rice using the soil analysis are reliable for a particular group of lowland soils. Thus, an experiment was conducted in the greenhouse, and the treatments made up of eleven lowland soils structured with a one-factor randomized block design, with four replications. The indicators were: iron extracted from the soil and the CEC, to estimate the percentage of saturation of CEC by Fe2+, percentage of symptoms of iron toxicity, weight of dry matter, and calcium, magnesium, iron and manganese contents in the soil solution and plant tissue. The results were subjected to analysis of variance (Duncan test) at 5% probability, and simple linear correlation of Pearson analyzes (whereas levels greater than 95%). The indicators which have the best efficiency to predict the risk of toxicity by iron is the iron concentrationt in the soil solution and PSFe2+. The PSFe2+ has a high correlation coefficient with the concentration of iron in the soil solution. No symptoms of toxicity by iron is observed when the mole ratio of iron by divalent cations in soil solution is less than 0.30. The extraction of iron by ammonium oxalate at pH 6.0 is a good indicator for estimating the iron that is accumulated during the flooding. The interpretation for prediction of the risk of occurrence of iron toxicity in rice proposed by SOSBAI (2007) based on PSFe2+ is efficient for predicting the occurrence of the problem for the group of soils in the study.
A toxidez de ferro pode causar reduções consideráveis na produtividade do arroz, dependendo da intensidade dos sintomas e da área afetada na lavoura. É necessário identificar os fatores que determinam a ocorrência dessa desordem nutricional, afim de que possam ser realizadas medidas efetivas para corrigir esse problema na lavoura. O objetivo do presente trabalho é verificar se os critérios de interpretação para prognóstico do risco de ocorrência da toxidez por ferro em arroz irrigado por alagamento a partir da análise de solo são válidos para um determinado grupo de solos de várzea. Para isso, foi conduzido um experimento em casa de vegetação, sendo os tratamentos compostos por onze solos de várzea estruturados num unifatorial com delineamento em blocos casualizados, com quatro repetições. Os indicadores avaliados foram: ferro extraído do solo e a CTC, para a estimação da porcentagem de saturação da CTC por Fe2+, porcentagem de sintomas de toxidez por ferro, peso de massa seca, e as concentrações de cálcio, magnésio, ferro e manganês na solução do solo e na parte aérea das plantas. Os resultados foram submetidos à análise de variância (teste de Ducan) a 5% de probabilidade, e realizadas análises de correlações lineares simples de Pearson (considerando níveis maiores que 95%). Os indicadores que apresentam a melhor eficiência para prever o risco de ocorrência de toxidez por ferro são a concentração de ferro na solução do solo e a PSFe2+. A PSFe2+ apresenta alto coeficiente de correlação com a concentração de ferro na solução do solo. Nenhum sintoma de toxidez por ferro é observado quando a fração molar de ferro pelos cátions divalentes na solução do solo é inferior a 0,30. A extração de ferro por oxalato de amônio a pH 6,0 é um bom indicador para se estimar o ferro que é acumulado durante o alagamento do solo. A interpretação para prognóstico do risco de ocorrência da toxidez por ferro em arroz irrigado proposto por SOSBAI (2007) baseada na PSFe2+ é eficiente para previsão da ocorrência do problema para o grupo de solos do estudo.

APA, Harvard, Vancouver, ISO, and other styles

3

Puntel, Robson Luiz. "Caracterização da atividade pró-oxidante de diferentes agentes e estudo do potencial antioxidante de intermediários do ciclo de krebs sobre alterações oxidativas induzidas in vitro." Universidade Federal de Santa Maria, 2008. http://repositorio.ufsm.br/handle/1/4400.

Full text

Abstract:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Previous data from the literature have shown that some Krebs cycle intermediates could act as antioxidant in several models, both in vitro and in vivo. However, the mechanism(s) involved in the antioxidant effect of Krebs cycle intermediates are not fully understood. Additionally, there are scarce data in the literature taking into account the in vitro effect of Krebs cycle intermediates during oxidative stress conditions. Thus, the aim of this study was to determine the effect of some Krebs cycle intermediates on lipid peroxidation induced in vitro by different pro-oxidant agents, and the mechanism(s) by which they act. Furthermore, it was necessary elucidate the mechanisms by which the different pro-oxidants acts under in vitro conditions. The present results showed that the malonate-induced TBARS production was not changed by potassium cyanide or MK-801. However, the pro-oxidant effect of quinolinic acid was significantly prevented by MK-801. In addition we found that both malonate and oxalate were able to form complexes with iron ions (Fe2+). Based on the presented results, we conclude that malonate pro-oxidant activity in vitro seems to be independent of the secondary excitotoxicity via indirect NMDA receptors activation. Additionally, we suggest that both the malonate and oxalate effect, in these experimental conditions, is due to its ability to form complexes with iron ions, thus modulating an adequate ratio Fe2+/Fe3+ that could cause an increase in free radicals generation. In contrast, the quinolinic acid effect seems to be dependent of the NMDA receptors activation. However, we can not rule out the involvement of iron ions in quinolinic acid toxicity under our assay conditions. Another objective of this study was to investigate the effect of some Krebs cycle intermediates against either basal or induced TBARS production, using rat brain S1 preparations and the mechanism(s) by which they act. The results showed that oxaloacetate, citrate, succinate, and malate were able to significantly prevent both basal and quinolinic acid-, iron- or malonate-induced TBARS production. On the other hand, fumarate prevented only malonate-induced TBARS production, without effect under basal conditions. However, α-ketoglutarate induced per se a significant increase in basal TBARS production. The antioxidant activity of fumarate and succinate were completely abolished when S1 was submitted to heat-treatment at 100ºC during 10 min. Likewise, potassium cyanide completely abolished the antioxidant effect of succinate. The effect of other Krebs cycle intermediates studied was unchanged with respect to heat-treatment, or cyanide. Except for succinate and fumarate, all intermediates used in this study were able to form complexes with iron (Fe2+) ions, however only oxaloacetate and α-ketoglutarate significantly prevented deoxyribose degradation induced by hydrogen peroxide. Based on the results presented, we concluded that oxaloacetate, malate, succinate, fumarate and citrate could act as antioxidants under such conditions, whereas α-ketoglutarate acts as a pro-oxidant agent per se. The mechanism(s) by which citrate, malate, and oxaloacetate acts seems to be related to their ability to form complexes with iron (Fe2+) ions, thus modulating the iron redox cycle. In contrast, the succinate and fumarate antioxidant effect seems to be dependent of the some enzymatic system.
Dados prévios da literatura têm mostrado que alguns intermediários do ciclo de Krebs podem agir como antioxidantes em diversos modelos, tanto in vitro, quanto in vivo. Porém, o(s) mecanismo(s) através dos qual(is) esses intermediários exercem suas atividades antioxidantes não são completamente entendidas. Considerando a escassez de dados na literatura a respeito do efeito dos intermediários do ciclo de Krebs durante situações de estresse oxidativo, o presente trabalho teve por objetivo determinar o efeito desses sob a peroxidação lipídica induzida por diferentes agentes pró-oxidantes in vitro, bem como investigar o(s) mecanismo(s) de ação dos mesmos. Além disso, faz-se necessário caracterizar o(s) mecanismos(s) pelo(s) qual(is) os diferentes pró-oxidantes agem nos sistemas in vitro. Os resultados dessa tese mostraram que a atividade pró-oxidante in vitro do malonato não foi modificada pela adição de cianeto de potássio, nem pelo MK-801. Por outro lado, o efeito pró-oxidante do ácido quinolínico foi significativamente prevenido pelo MK-801. Observamos ainda que o malonato, e também o oxalato foram capazes de formar complexos com íons ferrosos. Portanto, com base nos resultados encontrados, concluímos que o efeito pró-oxidante do malonato in vitro parece ser independente da excitotoxicidade secundária, conseqüência da ativação indireta dos receptores NMDA. Os resultados sugerem que o efeito do malonato e do oxalato nessas condições experimentais deve-se principalmente a sua capacidade de interagir com íons ferro, modulando uma razão Fe2+/Fe3+ que favorece a geração de radicais livres. Por outro lado, o efeito do ácido quinolínico parece ser devido à ativação dos receptores NMDA. Porém, não podemos excluir a participação dos íons ferro para a toxicidade do mesmo nessas condições. Outro foco deste estudo foi investigar o efeito de alguns intermediários do ciclo de Krebs na produção de TBARS basal ou induzida por diferentes pró-oxidantes em S1 de cérebro de ratos in vitro, bem como investigar o(s) mecanismo(s) de ação dos mesmos. Os resultados mostraram que o oxaloacetato, o citrato, o sucinato e o malato foram capazes de reduzir significativamente a produção de TBARS basal, bem como a induzida por ácido quinolínico, ferro ou malonato. O fumarato, por sua vez, teve efeito antioxidante somente sobre a produção de TBARS induzida. Por outro lado, o α-cetoglutarato foi capaz de induzir per se um significativo aumento na produção de TBARS. O efeito antioxidante do fumarato e do sucinato foi completamente abolido quando o S1 foi submetido a um prétratamento por 10 min a 100ºC, enquanto que o efeito dos demais intermediários permaneceu inalterado. Da mesma forma, a adição de cianeto de potássio aboliu completamente o efeito antioxidante do sucinato sem interferir significativamente no efeito dos demais intermediários estudados. Todos os intermediários estudados, exceto o sucinato e o fumarato, foram capazes de quelar íons ferro, porém somente o oxaloacetato e o α- cetoglutarato foram capazes de prevenir a degradação da desoxirribose induzida por peróxido de hidrogênio. Com base nos resultados obtidos, podemos concluir que o oxaloacetato, o malato, o sucinato, o fumarato e o citrato agem como antioxidantes sob determinadas condições, enquanto que o α-cetoglutarato age como um agente pró-oxidante per se. O mecanismo pelo qual o citrato, o malato e o oxaloacetato exercem seus efeitos antioxidantes parece ser devido à capacidade desses em interagir com íons ferro modulando o ciclo redox desse. Por outro lado, o efeito do sucinato e do fumarato parece ser devido a alguma atividade enzimática.

APA, Harvard, Vancouver, ISO, and other styles

4

Tailhades, Philippe. "Elaboration, caracterisation et optimisation des proprietes morphologiques et magnetiques de ferrites lacunaires destines a l'enregistrement haute densite." Toulouse 3, 1988. http://www.theses.fr/1988TOU30185.

Full text

Abstract:

Cette etude presente la mise au point de particules ferro ou ferrimagnetiques submicroniques dans le but d'ameliorer les performances a l'enregistrement magnetique haute densite (numerique). Tout d'abord, on a etudie les conditions de precipitations des precurseurs oxaliques a base de fer permettant d'obtenir des particules aciculaires dont les dimensions moyennes sont 0,2 mu m pour la longueur et 0,05 mu m pour le diametre. Par traitement thermique, on transforme ces precurseurs en ferrites lacunaires, en cherchant a obtenir des particules monocristallines monodomaines. En jouant sur l'anisotropie magnetocristalline grace a la substitution des ions fe**(3+) et des lacunes de gamma -fe::(2)o::(3) par des ions cobalt et du manganese, on a reussi a regler les proprietes magnetiques des particules (champ coercitif, aimantation remanente, aimantation saturation) de facon a les rendre compatibles avec les exigences de l'enregistrement magnetique haute densite

APA, Harvard, Vancouver, ISO, and other styles

5

Mandal, Sukhendu. "Investigations Of Open-Framework Metal Phosphates, Phosphites And Phosphite-Oxalate Materials." Thesis, 2007. http://hdl.handle.net/2005/506.

Full text

Abstract:

Open-framework inorganic materials constitute an important area of study in materials chemistry, because of their potential applications in areas such as sorption and catalysis. After the discovery of nanoporous aluminium phosphates by Flanigen et al in 1982, there has been a tremendous growth in the area of porous solids. Most of them are based upon oxygen containing materials especially phosphates, and they exhibit fascinating architectures with unusual bonding and coordination environment. Besides metal phosphates and phosphites, inorganic-organic hybrids constitute an important family of open-framework structures. In this thesis, results of investigations of a variety of open-framework metal phosphates, metal phosphites, as well as a new family of phosphite-oxalates are presented. More importantly, studies directed towards the synthesis and understanding of the magnetic properties of various transition metal phosphates, phosphites, phosphite-oxalates and the upconversion behavior of uranium phosphites are discussed at length. In Chapter 1 of the thesis an overview of inorganic open-framework materials is presented. In Chapter 2 and 3, the synthesis, structure of open-framework zinc (Part A of both Chapters) and synthesis, structure and magnetic properties of open-framework iron (Part B of both Chapters) are presented. Some of these compounds show unusual structure and interesting properties. For example, two-dimensional iron phosphate exhibits ferrimagnetism whereas three-dimensional iron phosphate with SBU-6 and SBU-2 is antiferromagnetic. The three-dimensional iron phosphite exhibits small polarization at low field. In Chapter 4, we present a new family of organically templated hybrid materials synthesized by partially substituting the phosphite by the oxalate ion in manganese, iron and cobalt phosphites. These exhibit a wide range of structures in which the oxalates play an unusual dual role. Some of these compounds show interesting magnetic properties. For example, manganese phosphite-oxalate shows magnetic polarizations on application of high field at low temperatures and iron phosphite-oxalate exhibit ferromagnetism at very low temperature. While a large number of organically templated transition and main-group element phosphites have been synthesized, research on lanthanide and actinide phosphites has been rare. Most of the reported open-framework phosphate and phosphite compounds of uranium possess uranium in +6 oxidation state. The possibility of building open architectures of uranium phosphites has been explored in Chapter 5. The results have been rewarding and both layered and three-dimensional structures have been prepared. Two of them contain uranium in +4 state and exhibit upconversion behavior.

APA, Harvard, Vancouver, ISO, and other styles

6

Abd, El-Samie Ihab Mohamed Farid. "Phosphordüngewirkung von Klärschlämmen aus Klärwerken mit Phosphateliminierung durch Eisensalze." Doctoral thesis, 2003. http://hdl.handle.net/11858/00-1735-0000-0006-AFFD-A.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Iron oxalate"

1

Holze, Rudolf. "Ionic conductance of iron oxalate." In Electrochemistry, 885. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-49251-2_832.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Pardasani, R. T., and P. Pardasani. "Magnetic properties of tetrathiafulvalene radical salt of dimetric iron(III) oxalate." In Magnetic Properties of Paramagnetic Compounds, 437–38. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-54231-6_241.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Pardasani, R. T., and P. Pardasani. "Magnetic properties of tetramethyltetrathiafulvalene radical salt of dimetric iron(III) oxalate." In Magnetic Properties of Paramagnetic Compounds, 439–40. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-54231-6_242.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Pardasani, R. T., and P. Pardasani. "Magnetic properties of tetrathiafulvalene radical salt of monomeric iron(III) oxalate." In Magnetic Properties of Paramagnetic Compounds, 451–52. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-54231-6_248.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Zhang, Keyu, Yin Li, Runhong Wei, Yunke Wang, Yongnian Dai, and Yaochun Yao. "Controllable Synthesis of Battery-Grade Iron Oxalate with Waste Ferrous Sulfate from Titanium Dioxide Production." In Energy Technology 2020: Recycling, Carbon Dioxide Management, and Other Technologies, 249–58. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-36830-2_24.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Pardasani, R. T., and P. Pardasani. "Magnetic properties of N, N′-diethyldithiocarbamatobis(oxalato)iron(III)." In Magnetic Properties of Paramagnetic Compounds, 172–73. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-53971-2_84.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Pardasani, R. T., and P. Pardasani. "Magnetic properties of bis(N, N′-diethyldithiocarbamato)-oxalato-iron(III)." In Magnetic Properties of Paramagnetic Compounds, 170–71. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-53971-2_83.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Choudhury, Amitava, Srinivasan Nataraja, and C. N. R. Rao. "Hybrid Open-Framework Iron Phosphate – Oxalates Demonstrating a Dual Role of the Oxalate Unit." In World Scientific Series in 20th Century Chemistry, 514–21. WORLD SCIENTIFIC, 2003. http://dx.doi.org/10.1142/9789812835734_0068.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Jordan, Robert B. "Inorganic Photochemistry." In Reaction Mechanisms of Inorganic and Organometallic Systems. Oxford University Press, 2007. http://dx.doi.org/10.1093/oso/9780195301007.003.0009.

Full text

Abstract:

Electromagnetic radiation in the form of UV and visible light has long been used as a reactant in inorganic reactions. The energy of light in the 200- to 800-nm region varies between 143 and 36 kcal mol-1, so it is not surprising that chemical bonds can be affected when a system absorbs light in this readily accessible region. Systematic mechanistic studies in this area have benefited greatly from the development of lasers that provided intense monochromatic light sources and from improvements in actinometers to measure the light intensity. Prior to the laser era, it was necessary to use filters to limit the energy of the light used to a moderately narrow region or to just cut off light below a certain wavelength. Pulsed-laser systems also allow much faster monitoring of the early stages of the reaction and the detection of primary photolysis intermediates. The systems discussed in this chapter have been chosen because of their relationship to substitution reaction systems discussed previously. For a broader assessment of this area, various books and review articles should be consulted. Mechanistic photochemistry incorporates features of both electron-transfer and substitution reactions, but the field has some of its own terminology, which is summarized as follows: The quantum yield,F , is the number of defined events, in terms of reactant or product, that occur per photon absorbed by the system. An einstein, E, is defined as a mole of photons, and if n is the moles of reactant consumed or product formed, then F = n/E. For simple reactions F£ 1 but can be >1 for chain reactions. An actinometer is a device used to measure the number of einsteins emitted at a particular wavelength by a particular light source. Photon-counting devices are now available and secondary chemical actinometers have been developed, such as that based on the Reineckate ion, Cr(NH3)2(NCS)4-, as well as the traditional iron(III)-oxalate and uranyl-oxalate actinometers. An early problem in this field was the lack of an actinometer covering the 450- to 600-nm range and the Reineckate actinometer solved this problem.

APA, Harvard, Vancouver, ISO, and other styles

10

Leenheer, Jerry A., and Gary E. Maciel. "Preparation of Low-Carbon Sediments from the Mississippi River and Certain Tributaries for Solid-state CPMAS 13C NMR Analysis." In Nuclear Magnetic Resonance Spectroscopy in Environment Chemistry. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195097511.003.0024.

Full text

Abstract:

The nature of organic carbon in aquatic sediments and soils with low carbon contents and significant contents of paramagnetic elements such as iron and manganese is difficult to assess by solid-state, cross-polarization magic angle spinning (CPMAS) 13C nuclear magnetic resonance (NMR) spectrometry because of the inherent low sensitivity of 13C NMR analyses, and band broadening and sensitivity losses caused by paramagnetic elements. Other investigators have addressed this problem in the analysis of soils by enriching the organic carbon content by flotation, by magnetic separation of paramagnetic minerals, and by chemical reduction of iron by stannous chloride and sodium dithionite. In this study, they found that satisfactory 13C NMR spectra could be obtained if the C/Fe ratio was greater than 1 wt%. Each of the physical and chemical treatments used to increase the C/Fe ratio resulted in losses of organic matter and changes in the nature of organic matter through physical fractionation and chemical alteration. Suspended stream sediments frequently have equivalent contents of organic carbon and sesquioxide coatings with which the organic matter is associated. These sesquioxide coatings consist predominantly of iron and manganese oxyhydroxides that cause problems with NMR analyses. In this chapter we describe a method to enrich organic matter and remove iron and manganese from low-carbon sediments sampled from the Mississippi, Illinois, and Ohio Rivers with minimal loss and alteration of the organic matter. The second objective is to characterize the sedimentary organic matter by 13C NMR using recent advances that increase instrument sensitivity. Suspended and bed sediments were collected during a sampling cruise on the Mississippi River during May–June 1990. Fine bed sediments were collected in depositional regions of the river or tributaries with a pipe dredge. Suspended silts were collected using a continuous-flow centrifuge operated on board the Research Vessel Acadiana. Both bed sediments and suspended silts were freeze-dried prior to additional treatment procedures and NMR analyses. A flow chart of selective mineral dissolution procedures is presented in Figure 17.1. The acid pyrophosphate treatment6 was placed first in the sequence to remove calcium and magnesium minerals that would form insoluble oxalates in the following extraction.

APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Iron oxalate"

1

Negrea, A., M. Ciopec, L. Lupa, C. Muntean, R. Lazau, and P. Negrea. "Kinetic and thermodynamic aspects of arsenic (III) adsorption onto iron oxide obtained from iron oxalate." In WATER POLLUTION 2010. Southampton, UK: WIT Press, 2010. http://dx.doi.org/10.2495/wp100111.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Smrčka, David, Vít Procházka, Petr Novák, Josef Kašlík, and Vlastimil Vrba. "Iron oxalate decomposition process by means of Mössbauer spectroscopy and nuclear forward scattering." In MÖSSBAUER SPECTROSCOPY IN MATERIALS SCIENCE 2016. Author(s), 2016. http://dx.doi.org/10.1063/1.4966008.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Zboril, Radek. "Nanocrystalline Iron(III) Oxides Formed under Dynamic Heating of Ferrous Oxalate Dihydrate in Air." In INDUSTRIAL APPLICATIONS OF THE MOSSBAUER EFFECT: International Symposium on the Industrial Applications of the Mossbauer Effect. AIP, 2005. http://dx.doi.org/10.1063/1.1923665.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Jaiswal, Shivendra Kumar, and Jitendra Kumar. "Sol-Gel Synthesis and Magnetic, Optical and Impedance Behaviour of Strontium Ferrite Powder." In ASME 2011 International Manufacturing Science and Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/msec2011-50067.

Full text

Abstract:

An attempt has been made to synthesize SrFeO3-δ powder by sol-gel process involving oxalate formation, its digestion for 4h, drying at 150°C for 24h, and decomposition at 800°C for 10h. The resulting powder is shown to a) exhibit a single phase with a perovskite-type cubic structure and lattice parameter a = 3.862±0.002A˚, b) contain irregular shape particles, and c) display optical absorption peaks corresponding to charge transfer from oxygen to iron (3.73 and 3.41eV), t2g to eg transition of Fe3+ (1.57eV), and crystal field (3d-3d) charge transfer of Fe3+ (1.25eV). Impedance over a wide frequency range of 20Hz-2MHz at 118–318K has contributions from two parallel ‘RC’ circuits belonging to bulk and grain boundaries with the later displaying significant space charge polarization. The relaxation time of polarization follows an Arrhenius behaviour (τ = τo exp[Ea/kBT]) with τo as ∼10−8s and activation energy Ea as ∼50meV. Further, the sample having magnetic character with transition temperature as 853K, coercivity (Hc) = 3748Oe and magnetization 0.09 μB per iron atom (at 17kOe). The zero field cooled and field cooled magnetization versus temperature data in conjunction with constricted hysteresis loops near the origin suggest core-shell morphology for the particles, core being antiferromagnetic with net uncompensated moment and shell conforming to disordered disposition of spins.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!