Relevant bibliographies by topics / Magnetite

Academic literature on the topic 'Magnetite'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 August 2024

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

Select a source type:

Contents

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

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 "Magnetite"

1

Mohd Yusoff, Ahmad Huzaifah, Midhat Nabil Ahmad Salimi, and Mohd Faizal Jamlos. "A New XRD Method to Quantitatively Distinguish Non-Stoichiometric Magnetite: Influence of Particle Size and Processing Conditions." Advanced Engineering Forum 26 (February 2018): 41–52. http://dx.doi.org/10.4028/www.scientific.net/aef.26.41.

Full text
Abstract:
Magnetite’s abilities rely on the quantitative phases present in the sample. Magnetite quality can strongly influence several physical properties, such as magnetism, catalytic performance, and Verwey transition. However, differentiation of magnetite and maghemite through the conventional X-ray diffractogram comparison are not relevant for the intermediate phases. In this study, the deviation from the ideal stoichiometric magnetite and the relative quantification of both phases were mathematically achievable through a new XRD technique. Various synthesis conditions were applied to obtain different crystallite sizes, in the range of 9 to 30 nm. Generally, the stoichiometric deviation and maghemite content would be significantly influenced by the final size, whereas system conditions (temperature of solution, agitation rate, and pH of solution) would only have minor significance. In this study, iron oxide nanoparticles prepared using the co-precipitation method was calculated to contain 100% magnetite for particles of 30.26 nm in size, while 100% maghemite was calculated for particles at 9.64 nm.
APA, Harvard, Vancouver, ISO, and other styles
2

Roh, Yul, Hee-Dong Jang, and Yongjae Suh. "Microbial Synthesis of Magnetite and Mn-Substituted Magnetite Nanoparticles: Influence of Bacteria and Incubation Temperature." Journal of Nanoscience and Nanotechnology 7, no. 11 (November 1, 2007): 3938–43. http://dx.doi.org/10.1166/jnn.2007.076.

Full text
Abstract:
Microbial synthesis of magnetite and metal (Co, Cr, Ni)-substituted magnetites has only recently been reported. The objective of this study was to examine the influence of Mn ion on the microbial synthesis of magnetite nanoparticles. The reductive biotransformation of an akaganeite (β-FeOOH) or a Mn-substituted (2–20 mol%) akaganeite (Fe1–xMnxOOH) by Shewanella loiha (PV-4, 25 °C) and Thermoanaerobacter ethanolicus (TOR-39, 60 °C) was investigated under anaerobic conditions at circumneutral pH (pH = 7–8). Both bacteria formed magnetite nanoparticles using akaganeite as a magnetite precursor. By comparison of iron minerals formed by PV-4 and TOR-39 using Mn-mixed akaganeite as the precursor, it was shown that PV-4 formed siderite (FeCO3, green rust [Fe2+Fe3+(OH)16CO3·4H2O], and magnetite at 25 °C, whereas TOR-39 formed mainly nm-sized magnetite at 60 °C. The presence of Mn in the magnetite formed by TOR-39 was revealed by energy dispersive X-ray analysis (EDX) is indicative of Mn substitution into magnetite crystals. EDX analysis of iron minerals formed by PV-4 showed that Mn was preferentially concentrated in the siderite and green rust. These results demonstrate that coprecipitated/sorbed Mn induced microbial formation of siderite and green rust by PV-4 at 25 °C, but the synthesis of Mn-substituted magnetite nanoparticles proceeded by TOR-39 at 60 °C. These results indicate that the bacteria have the ability to synthesize magnetite and Mn-substituted magnetite nano-crystals. Microbially facilitated synthesis of magnetite and metal-substituted magnetites at near ambient temperatures may expand the possible use of specialized ferromagnetic nano-particles.
APA, Harvard, Vancouver, ISO, and other styles
3

Ngadenin, Ngadenin, Frederikus Dian Indrastomo, Widodo Widodo, and Kurnia Setiawan Widana. "Identifikasi Keterdapatan Mineral Radioaktif pada Urat-Urat Magnetit di Daerah Ella Ilir, Melawi, Kalimantan Barat." EKSPLORIUM 40, no. 1 (July 31, 2019): 33. http://dx.doi.org/10.17146/eksplorium.2019.40.1.5350.

Full text
Abstract:
ABSTRAKElla Ilir secara administratif terletak di Kabupaten Melawi, Kalimantan Barat. Geologi regional daerah Ella Ilir tersusun atas batuan malihan berumur Trias–Karbon yang diterobos oleh batuan granitik berumur Yura dan Kapur. Keterdapatan mineral radioaktif di daerah tersebut terindikasi dari radioaktivitas urat-urat magnetit pada batuan malihan berumur Trias–Karbon dengan kisaran nilai 1.000 c/s hingga 15.000 c/s. Tujuan dari penelitian ini adalah menentukan jenis cebakan mineral bijih dan mengidentifikasi keterdapatan mineral radioaktif pada urat-urat bijih magnetit di daerah Ella Ilir. Metode yang digunakan adalah pemetaan geologi, pengukuran radioaktivitas, analisis kadar uranium, dan analisis mineragrafi beberapa sampel urat bijih magnetit. Litologi daerah penelitian tersusun oleh kuarsit biotit, metatuf, metabatulanau, metapelit, granit biotit, dan riolit. Sesar sinistral barat-timur dan sesar dekstral utara-selatan merupakan struktur sesar yang berkembang di daerah ini. Komposisi mineral urat-urat magnetit terdiri dari mineral-mineral bijih besi, sulfida, dan radioaktif. Mineral bijih besi terdiri dari magnetit, hematit, dan gutit. Mineral sulfida terdiri dari pirit, pirhotit, dan molibdenit sedangkan mineral radioaktif terdiri dari uraninit dan gumit. Keterdapatan urat-urat bijih magnetit dikontrol oleh litologi dan struktur geologi. Urat-urat magnetit pada metabatulanau berukuran tebal (1,5–5 m), mengisi rekahan-rekahan yang terdapat di sekitar zona sesar. Sementara itu, urat-urat magnetit pada metapelit berukuran tipis (milimetrik–sentimetrik), mengisi rekahan-rekahan yang sejajar dengan bidang sekistositas. Cebakan mineral bijih di daerah penelitian adalah cebakan bijih besi atau cebakan bijih magnetit berbentuk urat karena proses hidrotermal magmatik.ABSTRACTElla Ilir administratively located in Melawi Regency, West Kalimantan. Regional geology of Ella Ilir area is composed of metamorphic rocks in Triassic–Carboniferous age which are intruded by Jurassic and Cretaceous granitic rocks. Radioactive minerals occurences in the area are indicated by magnetite veins radioactivities on Triassic to Carboniferous metamorphic rocks whose values range from 1,000 c/s to 15,000 c/s. Goal of the study is to determine the type of ore mineral deposits and to identify the presence of radioactive mineral in magnetite veins in Ella Ilir area. The methods used are geological mapping, radioactivity measurements, analysis on uranium grades, and mineragraphy analysis of severe magnetite veins samples. Lithologies of the study area are composed by biotite quartzite, metatuff, metasilt, metapellite, biotite granite, and ryolite. The east-west sinistral fault and the north-south dextral fault are the developed fault structures in this area. Mineral composition of magnetite veins are consists of iron ore, sulfide, and radioactive minerals. Iron ore mineral consists of magnetite, hematit, and goetite. Sulfide minerals consist of pyrite, pirhotite, and molybdenite, while radioactive minerals consist of uraninite and gummite. The occurences of magnetite veins are controlled by lithology and geological structures. The magnetite veins in metasilt are thick (1.5–5 m), filled the fractures in the fault zone. Meanwhile, the magnetite veins in metapellite are thinner (milimetric–centimetric), filled the fractures that are parallel to the schistocity. The ore deposits in the study area are iron ore deposits or magnetite ore deposits formed by magmatic hydrothermal processes.
APA, Harvard, Vancouver, ISO, and other styles
4

Belov, Konstantin P. "Electronic processes in magnetite (or, "Enigmas of magnetite")." Uspekhi Fizicheskih Nauk 163, no. 5 (1993): 53. http://dx.doi.org/10.3367/ufnr.0163.199305c.0053.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

RAO, B. S. R., I. V. RADHAKRISHNA MURTHY, and Y. V. SUBBA RAO. "Results of a vertical magnetic survey near Karimnagar town, Karimnagar district, Andhra Pradesh." MAUSAM 25, no. 3 (February 21, 2022): 493–98. http://dx.doi.org/10.54302/mausam.v25i3.5263.

Full text
Abstract:
Magnetic surveys were conducted around Karimnagar town of Andhra Fradesh to trace the quartz-magnetite bodies and to determine the exact nature of the unexposed dykes known to be running through the local college and the surrounding areas. The results clearly state that the underground bodies are only dolerites and quartz-magnetites do not occur anywhere except at three places. Laboratory studies indicate that the magnetism necessary to produc6 the observed anomalies could be easily attributed to dolerites.
APA, Harvard, Vancouver, ISO, and other styles
6

Roh, Y., H. Vali, T. J. Phelps, and J. W. Moon. "Extracellular Synthesis of Magnetite and Metal-Substituted Magnetite Nanoparticles." Journal of Nanoscience and Nanotechnology 6, no. 11 (November 1, 2006): 3517–20. http://dx.doi.org/10.1166/jnn.2006.17973.

Full text
Abstract:
We have developed a novel microbial process that exploits the ability of Fe(III)-reducing microorganisms to produce copious amounts of extracellular magentites and metal-substituted magnetite nanoparticles. The Fe(III)-reducing bacteria (Theroanaerobacter ethanolicus and Shewanella sp.) have the ability to reduce Fe(III) and various metals in aqueous media and form various sized magnetite and metal-substituted magnetite nano-crystals. The Fe(III)-reducing bacteria formed metal-substituted magnetites using iron oxide plus metals (e.g., Co, Cr, Mn, Ni) under conditions of relatively low temperature (<70 °C), ambient pressure, and pH values near neutral to slightly basic (pH = 6.5 to 9). Precise biological control over activation and regulation of the biosolid-state processes can produce magnetite particles of well-defined size (typically tens of nanometers) and crystallographic morphology, containing selected dopant metals into the magnetite (Fe3−yXyO4) structure (where X = Co, Cr, Mn, Ni). Magnetite yields of up to 20 g/L per day have been observed in 20-L vessels. Water-based ferrofluids were formed with the nanometer sized, magnetite, and metal-substituted biomagnetite particles.
APA, Harvard, Vancouver, ISO, and other styles
7

Kahani, Seyed Abolghasem, and Zahra Yagini. "A Comparison between Chemical Synthesis Magnetite Nanoparticles and Biosynthesis Magnetite." Bioinorganic Chemistry and Applications 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/384984.

Full text
Abstract:
The preparation of Fe3O4from ferrous salt by air in alkaline aqueous solution at various temperatures was proposed. The synthetic magnetites have different particle size distributions. We studied the properties of the magnetite prepared by chemical methods compared with magnetotactic bacterial nanoparticles. The results show that crystallite size, morphology, and particle size distribution of chemically prepared magnetite at 293 K are similar to biosynthesis of magnetite. The new preparation of Fe3O4helps to explain the mechanism of formation of magnetosomes in magnetotactic bacteria. The products are characterized by X-ray powder diffraction (XRD), infrared (IR) spectra, vibrating sample magnetometry (VSM), and scanning electron microscopy (SEM).
APA, Harvard, Vancouver, ISO, and other styles
8

Rahmayanti, Maya, Sri Juari Santosa, and Sutarno. "Sonochemical Co-Precipitation Synthesis of Gallic Acid-Modified Magnetite." Advanced Materials Research 1101 (April 2015): 286–89. http://dx.doi.org/10.4028/www.scientific.net/amr.1101.286.

Full text
Abstract:
Gallic acid-modified magnetites were synthesized by one and two-step reactions via the newly developed sonochemical co-precipitation method. The two-step reaction included the formation of magnetite powder and mixing the magnetite powder with gallic acid solution, while the one-step reaction did not go through the formation magnetite powder. The obtained gallic acid-modified magnetites were characterized by the Fourier Transform Infrared (FTIR) spectroscopy, the X-Ray Diffraction (XRD) and the Scanning Electron Microscopy (SEM). More over, the magnetic properties were studied by using a Vibrating Sample Magnetometer (VSM). The characterization results showed that there were differences in crystalinity, surface morphology and magnetic properties of products that were formed by one and two-step reactions.
APA, Harvard, Vancouver, ISO, and other styles
9

Jackson, Mike J., and Bruce Moskowitz. "On the distribution of Verwey transition temperatures in natural magnetites." Geophysical Journal International 224, no. 2 (October 28, 2020): 1314–25. http://dx.doi.org/10.1093/gji/ggaa516.

Full text
Abstract:
SUMMARY The Verwey transition in magnetite is a crystallographic phase transition occurring in the temperature range 80–125 K and depends on stoichiometry and cation substitution, which may in turn serve as an indicator of the conditions under which magnetite was formed or altered in nature. We have analysed the distribution of Verwey transition temperatures (TV) in a large set of samples (N = 1110) from a wide variety of rocks, sediments, and other natural and synthetic materials containing magnetite, mined from the database of the Institute for Rock Magnetism and from published studies. The analysis is restricted to measurements of remanence while warming through the transition from which TV was determined by the derivative method. Our analysis showed that the TV distribution exhibited a generally bimodal distribution of Verwey transition temperatures, both for the entire data set and for almost all of the lithological subsets. There is a sharp peak for values in the range 118–120 K, and a broad, relatively flat or polymodal distribution from about 98 to 118 K. The upper end of the distribution was sharp, with only a few values exceeding 124 K, and the tail on the lower end extended down to about 80 K. Virtually all of the sample types exhibited polymodal distributions, almost always with one peak near 120 K, and with one or more additional peaks at lower temperatures. Biogenic magnetites produced by magnetotactic bacteria had the lowest modal value of TV (100 K). Loesses (103.5 K) and igneous extrusives (102.5 K) also had low modal transition temperatures and distributions with dominant low-TV peaks. Lithological groups with the highest modal transition temperatures were modern soils (119.5 K), silicate minerals with exsolved magnetite (119 K) and sedimentary rocks (119 K). Numerical experiments confirmed that the derivative method for the determination of TV was reasonably robust and that the observed distributions cannot be explained as an artefact related to the determination of TV from individual thermomagnetic runs but rather is a general characteristic of natural magnetites. The results provide context for studies that interpret TV in particular samples in terms of natural processes or conditions during formation or alteration of magnetite.
APA, Harvard, Vancouver, ISO, and other styles
10

Agnestisia, Retno. "Synthesis & Characterization of Magnetit (Fe3O4) and Its Applications As Adsorbent Methylene Blue." Jurnal Sains dan Terapan Kimia 11, no. 2 (October 3, 2017): 61. http://dx.doi.org/10.20527/jstk.v11i2.4039.

Full text
Abstract:
Synthesis, characterization and adsorption study of magnetite have beenconducted. Magnetite was synthesized by coprecipitation method. The characterizations of magnetite were carried out with spectroscopy FTIR (Fourier Transform Infrared) and XRD (X-ray diffraction). The adsorption study was conducted using a batch system with the studied adsorption study including optimum pH, optimum contact time and adsorption equilibrium. The results showed that coprecipitation method has succeeded to form magnetite that has magnetism properties. Magnetite can adsorbed methylene blue from aqueous phase, with the maximum adsorption at pH 5 and contact time of 90 minutes.Adsorption of methylene blue by magnetite follows the adsorption pattern of the Langmuir isotherm with the adsorption energy of 25.59 kJ/mol and adsorption capacity of 43.86 mg/g. The results of magnetite synthesis can accelerate the process of separating the adsorbent particles in a methylene blue solution using an external magnetic field.Keywords : magnetite, coprecipitation, adsorption, and methylene blue.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Magnetite"

1

Chatman, Shawn Michael Edward. "Morphological and magnetic characterization of electrodeposited magnetite /." Internet access available to MUN users only, 2005. http://collections.mun.ca/u?/theses,85053.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Muxworthy, Adrian R. "Stability of magnetic remanence in multidomain magnetite." Thesis, University of Oxford, 1998. http://ora.ox.ac.uk/objects/uuid:bc70e665-4c54-4ab5-98fa-d43ccecd07a1.

Full text
Abstract:
If a rock is to retain a geologically meaningful magnetic record of its history, it is essential that it contains magnetic minerals which are capable of carrying stable magnetic remanence. Of the natural occurring magnetic minerals, magnetite is the most important because of its abundance and strong magnetic signature. The stability, i.e., the resistance to demagnetisation or reorientation, of magnetic remanence is related to grain size; in smaller grains the magnetic moments align to have single domain (SD) structures, in larger grains complex magnetic patterns are formed (multidomain (MD)). “Classical” domain theory predicts that SD remanence is stable, whilst MD remanence is not. However experimental evidence has shown that both SD and MD grains can have stable remanences. In this thesis the origin of stable MD remanence is examined. There are two opposing theories; one suggests that the stability is due to independent SD-like structures, the other postulates that the stability is due to metastable MD structure. A series of experiments were designed to examine the stability using a selection of characterised synthetic and natural samples. Low-stress hydrothermal recrystallised samples where grown for this study. For the first time, the stability of thermoremanence induced in hydrothermal crystals to cooling was examined. The results agree with previous observations for crushed and natural magnetites, and support kinematic models. The behaviour of SIRM and thermoremanences in MD magnetite to low-temperature cooling to below the crystallographic Verwey transition at 120-124 K (Tv) and the cubic magnetocrystalline anisotropy isotropic point (Tk) at 130 K was investigated. On cooling through Tv, SIRM was observed to decrease and demagnetise, however thermoremanence was found to display a large increase in the magnetisation at Tv, which was partially re- versible on warming. The size of the anomaly is shown to be dependent on the temperature at which the thermoremanence is acquired, internal stress and grain size. The anomaly is attributed to the large increase in the magnetocrystalline anisotropy which occurs on cooling through Tv . It is postulated that low-temperature cycling demagnetisation is due to kinematic processes which occur on cooling between room temperature and Tk. Characterisation of low-temperature treated remanence and partially alternating field demagnetised remanence, suggest that the stable remanence is multidomain. Low-temperature cooling of remanence in single sub-micron crystals was simulated using micromagnetic models. The models predict the observed anomaly for thermoremanence on cooling through Tv, and also the relative behaviour of SIRM and thermoremanence. The single domain threshold was calculated for the low-temperature phase of magnetite, and was found to be 0.14 microns, compared to 0.07 microns at room temperature.
APA, Harvard, Vancouver, ISO, and other styles
3

Owings, Paul C. "High Gradient Magnetic Separation of nanoscale magnetite." Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/12020.

Full text
Abstract:
Master of Science
Department of Civil Engineering
Alexander P. Mathews
Nanoscale magnetite is being examined for possible uses as an adsorbent of heavy metals and for the enhancement of water treatment processes such as stripping of trichloroethylene (TCE) from contaminated water supplies and wastewaters. Methods for recovering nanoscale magnetite must be developed before the particles can be used in water treatment processes. This is necessary because expelling high amounts of particles into the environment will be unacceptable and costly; if captured they can be reused; additionally, they could potentially cause environmental impacts due to their stability in an aqueous environment and possible toxicity. Nanoscale magnetite is superparamagnetic, so it has a high magnetic susceptibility, and hence it is very attracted to magnetized materials. Utilizing the magnetic properties of magnetite may be one possible means of separating the particles from a treatment process. High Gradient Magnetic Separation (HGMS) has been studied for the separation of micron and even tenths of a micron size particles, but there is little experimental data for HGMS of nanoscale magnetite. This research looks to filter nanoscale magnetite through a HGMS and determine the capture efficiency of the filter. Subsequently, the filter was backwashed to determine particle recover efficiencies. The flow rate was adjusted to determine the dependency of particle capture efficiency on cross sectional velocity through the filter. Additionally, particle loading was changed to better understand the correlation of particle loading with capture efficiency. Filtrations for nanoscale magnetite dispersed with sodium tripolyphosphate were also completed as well as filtrations of nanoscale magnetite coated with silica and magnetite silica composites. Experimental data in this research indicates that magnetite nanoparticles can be captured at 99.8% efficiency or higher in a well-designed filtration system. Capture efficiencies around 99.8% have been found for magnetite. The silica coated magnetite and magnetite silica composites were captured at efficiencies as high as 96.7% and 97.9%, respectively. The capture efficiency of the dispersed magnetite is lower than non-dispersed magnetite and most promising at relatively low fluid flow velocities and particle loadings. The maximum capture efficiency for dispersed magnetite particles was 90.3%. Both magnetite and dispersed magnetite were successfully recovered using backwash at pH of 10 to 11.
APA, Harvard, Vancouver, ISO, and other styles
4

Harrison, Richard John. "Magnetic properties of the magnetite-spinel solid solution." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603779.

Full text
Abstract:
The intrinsic magnetic properties of Fe-bearing solid solutions with the "spinel" crystal structure are determined to a large extent by the processes of non-convergent cation ordering and subsolvus exsolution. The aim of this dissertation is to investigate the interaction between these processes and the magnetic properties of the magnetite-spinel solid solution, with a view to assessing how these factors might influence the acquisition of natural remanent magnetization in other Fe-bearing solid solutions. Temperature and compositional variations in the state of non-convergent cation order are determined using a macroscopic thermodynamic theory, which is calibrated using cation ordering and phase equilibrium constraints from the literature. The cation distribution in the solid solution is calculated for various temperatures and used to derive the ideal variation in saturation magnetization as a function of composition. A compensation point is predicted at approximately 70 mol% MgA12O4, which is confirmed by experimental measurement of the saturation magnetization in synthetic samples. The magnetic properties of synthetic samples are sensitive to rapid changes in the distribution of Fe2+ and Fe3+ cations which occur during quenching. The kinetics of this ordering process are investigated using the Ginzburg-Landau rate law, which is used to calculate the ordering behaviour during quenching, isothermal annealing and temperature ramp experiments. The calculations show that rapid relaxation of the Fe2+-Fe3+ distribution occurs when intermediate members of the solid solution are heated above 400°C, and there is hysteresis in the degree of order during repeated heating and cooling cycles. Both these effects are confirmed by measurements of magnetic susceptibility versus temperature.
APA, Harvard, Vancouver, ISO, and other styles
5

Macêdo, Gleyguestone Lopes de 1983. "Síntese e caracterização magnética de nanopartículas do tipo dímero de Ag-Fe3O4." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/278116.

Full text
Abstract:
Orientador: Kleber Roberto Pirota
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
Made available in DSpace on 2018-08-20T23:05:11Z (GMT). No. of bitstreams: 1 Macedo_GleyguestoneLopesde_M.pdf: 4864713 bytes, checksum: a6eff7f69f1d64274cacac58dc118e5c (MD5) Previous issue date: 2012
Resumo: Neste trabalho, seguindo uma nova rota de síntese, foram produzidas três amostras de nanopartículas do tipo dímero de prata com magnetita (Ag-Fe3O4), onde a única diferença entre elas é no valor da concentração de partículas de prata utilizadas na síntese. As amostras de tipo dímero possuem concentrações de prata iguais a 0,003 g/mL, 0,007 g/mL e 0,01 g/mL e foram chamadas, respectivamente, de AgFeO_1, AgFeO_2 e AgFeO_3. Sobre estes sistemas realizaram-se medidas da magnetização do tipo Zero Field cooling/Field cooling (ZFC-FC) onde se observou nos três sistemas um aumentou brusco da temperatura de irreversibilidade (Tirr) da magnetita quando unida a prata. Também se observou que somente na amostra com menor concentração de prata sofre um grande aumento em sua temperatura de bloqueio (T B), aproximadamente 130K, que pode ser devido a fatores como aumento do tamanho da partícula de magnetita contida no dímero, aglomerações e interações entre particulas. Porém, através de medidas de dicroísmo circular magnético de raios-X (XMCD) observou-se que com a união da prata a magnetita provoca nesta um aumento de seu momento orbital sendo mais intenso para a amostra com menor concentração de prata (AgFeO_1). Tal resultado pode explicar o aumento em Tirr e TB, já que o momento orbital é diretamente proporcional à anisotropia magnética. Por fim, gostaria de salientar que, em conjunto com meu orientador (Prof. Kleber Roberto Pirota) foi decidido optar por uma estrutura na qual inicio com descrição das bases teóricas de interesse, logo comento rapidamente sobre as técnicas experimentais utilizadas e, finalmente, anexo os trabalhos publicados. Porém, como alguns resultados obtidos neste trabalho ainda não foram publicados, decidi resumir-los no final da tese (capítulo 4)
Abstract: In this work, following a new synthesis route, three samples were produced nanoparticle type silver dimer with magnetite (Ag-Fe3O4), where the only difference between them is the value of the concentration of silver particles used in the synthesis. Samples of dimer type silver concentrations have equal 0,003 g/mL, 0,007 g/mL e 0,01 g/mL and were named, respectively AgFeO_1, and AgFeO_2 AgFeO_3. On these systems were expressed as the magnetization of the type Zero Field cooling/Field cooling (ZFC-FC) where it was observed in all three systems a sudden increase in temperature of irreversibility (T IRR) of magnetite attached to silver. It was also observed that the sample with only low silver concentration undergoes a sharp increase in its temperature block (TB), to approximately 130K, which may be due to factors such as increasing the particle size of magnetite contained in the dimer interactions and agglomerations. However, through measures of magnetic circular dichroism X-ray (XMCD) observed that with the union of silver magnetite causes this increased their orbital momentum being more intense for the sample with lower concentration of silver (AgFeO_1). This result may explain the increase in TB and TIRR, since the orbital momentum is directly proportional to the magnetic anisotropy. Finally, let me emphasize that, together with my advisor (Prof. Kleber Roberto Pirota) it was decided to opt for a structure in which beginning with a description of the theoretical bases of interest, just comment quickly on the experimental techniques used and eventually annex published works. However, as some results of this work have not yet been published, I decided to summarize them at the end of the thesis (Chapter 4)
Mestrado
Física
Mestre em Física
APA, Harvard, Vancouver, ISO, and other styles
6

Arredondo, Melissa Gayle. "Zero-Dimensional Magnetite." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14151.

Full text
Abstract:
Low-dimensional magnetic systems are of interest due to several new effects and modifications that occur at sizes below the average domain grain boundary within the bulk material. Molecule-like magnetite (Fe3O4) nanoparticles, with sizes ranging from one to two nm were synthesized and characterized in order to investigate new properties arising from quantum size effects. These small systems will provide opportunities to investigate magnetism of zero-dimension systems. A zero-dimensional object is usually called a quantum dot or artificial atom because its electronic states are few and sharply separated in energy, resembling those within an atom. Since the surface to volume ratio is the highest for zero-dimensional systems, most of the changes to magnetic behavior will be observed in ultra-fine magnetic particles. Chemically functional magnetic nanoparticles, comprised of a Fe3O4 magnetite core encased in a thin aliphatic carboxylate, have been prepared by sequential high temperature decomposition of organometallic compounds in a coordinating solvent. In this work, aliphatic carboxylic acid chain length, reaction temperature and duration were varied to produce small core diameters. In order to correlate size effects with changes in particle formation, it is important to have a through understanding of the structural components. This includes studies of the core size, surface effects, decomposition, electronic properties and magnetic behavior. Quantum size effects were observed in the (Fe3O4)X(carboxylate)Y monolayer protected clusters (MPCs) when the average core diameter was ≤ 2.0 nm, evidenced by a blue shifted absorbance band maxima, suggesting the onset of quantum confinement. These (Fe3O4)X(carboxylate)Y MPCs also posses a complex interplay between surface and finite size effects, which govern the magnetic properties of these zero-dimensional systems. These MPCs are all superparamagnetic above their blocking temperatures with total magnetic anisotropy values greater than the bulk value due to an increase in surface and magnetocrystalline anisotropy. A non-linear decrease in saturation magnetization (MS) [Bohr Magneton] per cluster) as a function of the reciprocal of core radius have been attributed to surface effects such as a magnetically inactive layer or an increase in spin disorder as core diameter decreases. The reduced core dimensions of these MPCs make them ideal candidates for further investigation of quantum magnetic systems.
APA, Harvard, Vancouver, ISO, and other styles
7

Vieira, Raquel Nadine Cadete. "Coating of magnetite nanoparticles with chitosan for magnetic hyperthermia." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/21895.

Full text
Abstract:
Mestrado em Materiais e Dispositivos Biomédicos
O cancro é uma das doenças com maior ocorrência na população mundial e com uma elevada taxa de mortalidade. Os principais problemas na luta contra o cancro prendem-se com a dificuldade de diagnóstico precoce, a citotoxicidade associada aos fármacos anticancerígenos usados em quimioterapia convencional e a falta de tratamentos mais eficazes. Com o advento da nanotecnologia, tem havido um crescente interesse na aplicação de nanopartículas e nanoestruturas, nas mais diversas áreas da ciência, nomeadamente em aplicações biomédicas. Neste contexto em particular, as nanopartículas magnéticas apresentam propriedades interessantes, por exemplo, em sistemas de libertação controlada de fármaco e em hipertermia. A sua aplicação em áreas relacionadas com a saúde, como o tratamento de cancro por hipertermia magnética, passa necessariamente por uma boa caracterização das suas propriedades e pela correta avaliação das suas capacidades de libertação de energia sob a forma de calor por indução magnética. Nesse sentido, este trabalho teve como objetivo a síntese de nanopartículas de magnetite devido a sua compatibilidade com o organismo humano e propriedades magnéticas. No entanto, devido ao seu elevado grau de agregação assim como facilidade de oxidação em meios aquosos existe uma necessidade de revestir estas partículas. Para tal, foi utilizado um biopolímero: a quitosana. A ligação do revestimento da quitosana ao núcleo do óxido de ferro foi realizada através de dois tipos de ancoragem: através da dopamina, conhecida pela sua grande afinidade aos grupos aminas e através do ácido cafeico, por apresentar uma similaridade estrutural à dopamina. Para a caracterização estrutural e morfológica das partículas recorreu-se à difração de raios-X (DRX), à espetroscopia de infravermelhos com transformada de Fourier (FTIR), à dispersão dinâmica da luz (DLS), ao Potencial Zeta e à microscopia eletrónica de transmissão (TEM). As propriedades magnéticas foram medidas por magnetometria de SQUID (Superconducting Quantum Interferance Device). Por fim foi avaliada a capacidade das partículas sintetizadas para aplicação em hipertermia magnética.
Cancer is a disease with high incidence in the world population and equally with a high mortality rate. The main problems in the fight against cancer are linked to the difficulty of early diagnosis, the cytotoxicity associated with anticancer drugs used in conventional chemotherapy and the lack of more effective treatments. With the advent of nanotechnology, there has been increasing interest in the application of nanoparticles and nanostructures, in several areas of science, such as biomedicine. In this context, the magnetic nanoparticles have interesting properties in controlled drug release systems and hyperthermia. Its application in areas related to health, such as the treatment of cancer by magnetic hyperthermia, necessarily requires a good characterization of their properties and the correct assessment of their ability to release energy in the form of heat by magnetic induction. Therefore, this study aimed the synthesis of nanoparticles of magnetite due to their biocompatibility and magnetic properties. However, due to their high degree of aggregation as well as facile oxidation in aqueous media there is a need to coat these particles. For this purpose, a biopolymer was used: chitosan. The binding of the coat to the core of the iron oxide was accomplishment through two types of anchorages molecules: dopamine, knowing for their great affinity with amine groups and through caffeic acid due to structural similarity to dopamine. The structural and morphological characterization was performed using X-ray diffraction (DRX), Fourier transformed infrared spectroscopy (FTIR), dynamic light scattering (DLS), Zeta Potential; thermalgravimetric analysis and transmission electron microscopy (TEM). The magnetic properties were studied using a Superconducting Quantum Interference Device (SQUID) magnetometer. Finally, we evaluated the ability of some of the synthesized NPs for use in magnetic hyperthermia.
APA, Harvard, Vancouver, ISO, and other styles
8

Dudchenko, N. O., A. B. Brik, Y. V. Kardanets, and O. E. Grechanivskyy. "Influence of Ultrasound Treatment on the Properties of Synthetic Magnetite Nanoparticles." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35186.

Full text
Abstract:
The paper describes creation of magnetite nanoparticles under ultrasound treatment and investigation of their phase composition and magnetic properties. Magnetite nanoparticles were synthesized via coprecipitation of Fe+2 and Fe+3 with KOH in aqueous solution at 80°C. It was shown, that ultrasound treatment of solution during the synthesis of magnetite nanoparticles leads to the increasing of size and saturation magnetization obtained nanoparticles. The results of X-ray diffraction measurements show that the synthesized particles consist of magnetite. The size of synthesized magnetite nanoparticles according to Xray diffraction measurements was approximately 10 nm. Saturation magnetization of synthesized magnetite nanoparticles is rather high (37 A*m2/kg). Synthesized magnetite nanoparticles are promising for different medical-biological applications. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35186
APA, Harvard, Vancouver, ISO, and other styles
9

Virdee, D. "The influence of magnetostatic interactions on the magnetic properties of magnetite." Thesis, University of Edinburgh, 1999. http://hdl.handle.net/1842/14612.

Full text
Abstract:
The effect of magnetostatic interactions on the magnetisation structure and magnetic properties of magnetite grains for the size range 0.03 - 0.15 microns has been examined. The understanding of magnetostatic interactions is important because magnetite that occurs naturally by some precipitation process and in sedimentary rocks containing magnetosomes may form as magnetostatic interacting clumps of grains. This has implications in the way we perceive magnetic signals are recorded in rocks, bacterial magnetosomes found in sedimentary rocks, and also in magnetic recording media. The examination of magnetostatic interactions has been achieved by using a three-dimensional micromagnetic model which considers arrays of 4x4x4 cubic magnetite grains with uniaxial shape anisotropy and arrays of 6x6 or 4x4 cubic grains, arranged analogous to arrays of particles that may be produced by a method of electron beam lithography. The grains have a maximum spacing of one grain width, when they are seen to be non-interacting: or a minimum where they are almost touching, when they are interacting. Using this method it is possible to see how grain interactions alter the magnetic domain structure of uniform and non-uniform grains. The effect of interactions on bulk properties, such as coercivity and remanence can be examined from simulated hysteresis cycles. Properties are examined when the grains are arranged within the arrays such that their easy axes of magnetocrystalline anisotropy are aligned parallel with every other grain in the array, and in the case where the axes are in a randomly differing orientation from every other grain within the array. Hysteresis parameters for non-interacting and interacting arrays of grains are calculated, and these theoretical values are compared with previous theoretical micromagnetic models and experimental work. The results from this study are in good agreement with previous work.
APA, Harvard, Vancouver, ISO, and other styles
10

Newcombe, Lee. "The effects of screw dislocations on the magnetic properties of magnetite." Thesis, University of Edinburgh, 1998. http://hdl.handle.net/1842/15500.

Full text
Abstract:
The values of the hysteresis parameters produced by micromagnetic models are usually lower than those found experimentally, and in the case of grains which have been subjected to stress the simulated values can be as much as an order of magnitude too low. It has been suggested that the presence of crystalline defects within these stressed grains may be responsible for raising the coercivity and saturation remanence values in comparison with unstressed grains. Grains of magnetite containing a regular array of screw dislocations are modelled for different grain sizes and different dislocation densities using a micro-magnetic model which considers the exchange, demagnetising, magnetoelastic, magnetocrystalline anisotropy and external field interactions. It is found that the values obtained from the new model for coercivity and saturation remanence rise with increasing dislocation density in line with experimental results. Models containing dislocations are found to have the magnetic properties of defect-free grains of smaller grain size, again in line with experiment. The unblocking temperature of a 1μm grain of magnetite in zero applied field is found to decrease in an approximately linear manner with increasing dislocation density. This thesis shows that by considering the magnetoelastic energy arising from the presence of screw dislocations the discrepancy between the hysteresis parameters of magnetite obtained theoretically and experimentally may be resolved.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Magnetite"

1

Sandoval, Otilio Arturo Acevedo. La piedra imán del cerro Cangandhó, Zimapán, Hidalgo. Pachuca, Hidalgo, México: Universidad Autónoma del Estado de Hidalgo, 2007.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Sandoval, Otilio Arturo Acevedo. La piedra imán del cerro Cangandhó, Zimapán, Hidalgo. Pachuca, Hidalgo, México: Universidad Autónoma del Estado de Hidalgo, 2007.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Sandoval, Otilio Arturo Acevedo. La piedra imán del cerro Cangandhó, Zimapán, Hidalgo. Pachuca, Hidalgo, México: Universidad Autónoma del Estado de Hidalgo, 2007.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Mackenzie, George C. Magnetic concentration experiments: With iron ores of the Bristol Mines, Que. iron ores of the Bathurst Mines, New Brunswick, a copper nickel ore from Nairn, Ontario. Ottawa: Govt. Print. Bureau, 1992.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Overstreet, William C. Review of the use of magnetic concentrates in geochemical exploration. [Reston, Va.?]: Dept. of the Interior, U.S. Geological Survey, 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Overstreet, William C. Review of the use of magnetic concentrates in geochemical exploration. [Reston, Va.?]: Dept. of the Interior, U.S. Geological Survey, 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Overstreet, William C. Review of the use of magnetic concentrates in geochemical exploration. [Reston, Va.?]: Dept. of the Interior, U.S. Geological Survey, 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

Hancock, Kirk D. Magnetite occurrences in British Columbia. Victoria, B.C: British Columbia Geological Survey, 1988.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

Angrove, Dawn M. Magnetite: Structure, properties, and applications. Hauppauge, N.Y: Nova Science Publishers, 2010.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

M, Stebnovskai͡a I͡U. Magnetity zhelezorudnykh mestorozhdeniĭ. Kiev: Nauk. dumka, 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Magnetite"

1

DeArmitt, Chris. "Magnetite." In Encyclopedia of Polymers and Composites, 1–11. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-37179-0_34-1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

DeArmitt, Christopher. "Magnetite." In Polymers and Polymeric Composites: A Reference Series, 1–13. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-642-37179-0_34-2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Pinti, Daniele L. "Magnetite." In Encyclopedia of Astrobiology, 1. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-27833-4_922-6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Pinti, Daniele L. "Magnetite." In Encyclopedia of Astrobiology, 1427–28. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-44185-5_922.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Pinti, Daniele. "Magnetite." In Encyclopedia of Astrobiology, 949. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-11274-4_922.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

DeArmitt, Christopher. "Magnetite." In Fillers for Polymer Applications, 245–57. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-28117-9_34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Pinti, Daniele L. "Magnetite." In Encyclopedia of Astrobiology, 1. Berlin, Heidelberg: Springer Berlin Heidelberg, 2021. http://dx.doi.org/10.1007/978-3-642-27833-4_922-7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Ammen, C. W. "Magnetite." In Recovery and Refining of Precious Metals, 357–62. Boston, MA: Springer US, 1997. http://dx.doi.org/10.1007/978-1-4615-7721-8_16.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Pinti, Daniele L. "Magnetite." In Encyclopedia of Astrobiology, 1742. Berlin, Heidelberg: Springer Berlin Heidelberg, 2023. http://dx.doi.org/10.1007/978-3-662-65093-6_922.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Gooch, Jan W. "Synthetic Magnetite." In Encyclopedic Dictionary of Polymers, 725. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_11493.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Magnetite"

1

Maris, G., L. Jdira, J. Hermsen, S. Murphy, I. Shvets, and S. Speller. "Nano-magnetic probing on magnetite (110)." In INTERMAG 2006 - IEEE International Magnetics Conference. IEEE, 2006. http://dx.doi.org/10.1109/intmag.2006.375592.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Saylymby, Dayana Yu, Petr G. Dyadkov, and Nikolay Ed Mikhaltsov. "Curie temperature of the rocks of the Zarechenskay magnetic anomaly (East coast of Lake Baikal)." In Недропользование. Горное дело. Направления и технологии поиска, разведки и разработки месторождений полезных ископаемых. Экономика. Геоэкология. Федеральное государственное бюджетное учреждение науки Институт нефтегазовой геологии и геофизики им. А.А. Трофимука Сибирского отделения Российской академии наук, 2020. http://dx.doi.org/10.18303/b978-5-4262-0102-6-2020-064.

Full text
Abstract:
The Curie temperature of rock samples of the Zarechenskaya magnetic anomaly region is determined. The source of this anomaly is an array of Archean rocks, composed mainly of gneiss–granits. The obtained values of the Curie temperature indicate that the magnetism of these rocks is due to magnetite. Both knowledge of the Curie temperature and the magnetic mineral responsible for the magnetism of this rock massive is important for interpreting the results of tectonomagnetic monitoring performed here since 1984, as well as for solving geothermal problems.
APA, Harvard, Vancouver, ISO, and other styles
3

Rodriguez, Anselmo F. R., Fernando S. E. D. V. Faria, Jorge L. Lopez, Antonio G. G. Mesquita, José A. H. Coaquira, Aderbal C. Oliveira, Ricardo B. Azevedo, et al. "Mössbauer Characterization of Magnetite∕Polyaniline Magnetic Nanocomposite." In 8TH INTERNATIONAL CONFERENCE ON THE SCIENTIFIC AND CLINICAL APPLICATIONS OF MAGNETIC CARRIERS. AIP, 2010. http://dx.doi.org/10.1063/1.3530045.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Elkafrawy, S., S. R. Hoon, D. B. Lambrick, P. R. Bissell, and C. Price. "Polymeric stabilization of colloidal magnetite magnetic fluids." In International Conference on Magnetics. IEEE, 1990. http://dx.doi.org/10.1109/intmag.1990.734444.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Han, Lei, Shuangyan Li, Yong Yang, Fengmei Zhao, Jie Huang, and Jin Chang. "Research on the Structure and Performance of Bacterial Magnetic Nanoparticles." In 2007 First International Conference on Integration and Commercialization of Micro and Nanosystems. ASMEDC, 2007. http://dx.doi.org/10.1115/mnc2007-21137.

Full text
Abstract:
Magnetite nanocrystal has been widely used in many fields. Recently, a new magnetite nanocrystal, called magnetosome, has been found in magnetotactic bacteria. In this article, we researched on the properties of magnetosomes detailedly, such as crystalline, morphology, crystal-size distributions, vitro cytotoxicity, and magnetic properties and quantified primary amino groups on the magnetosomes membrane surface by fluorescamine assay for the first time. From the results, it was clear that magnetosomes have more potential in the biomedical applications than synthetic magnetite.
APA, Harvard, Vancouver, ISO, and other styles
6

FERGUSON, R. MATTHEW, AMIT P. KHANDHAR, KEVIN R. MINARD, and KANNAN M. KRISHNAN. "SIZE-OPTIMIZED MAGNETITE NANOPARTICLES FOR MAGNETIC PARTICLE IMAGING." In Proceedings of the First International Workshop on Magnetic Particle Imaging. WORLD SCIENTIFIC, 2010. http://dx.doi.org/10.1142/9789814324687_0007.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Ionita, Valentin, Emil Cazacu, and Lucian Petrescu. "Remarks about the magnetic characterization of magnetite nanopowders." In 2017 10th International Symposium on Advanced Topics in Electrical Engineering (ATEE). IEEE, 2017. http://dx.doi.org/10.1109/atee.2017.7905176.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Lee, Taeseung, Jong Hyuk Lee, and Yong Hoon Jeong. "Pool Boiling and Flow Boiling CHF Enhancement at Atmospheric Pressure Using Magnetic Nanofluid." In 2012 20th International Conference on Nuclear Engineering and the ASME 2012 Power Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/icone20-power2012-55094.

Full text
Abstract:
In this study, we suggest a new working fluid: magnetic nanofluid, or magnetite-water nanofluid, which is a colloidal suspension of magnetite nanoparticles in the pure water. By using the nanofluid, we can expect the critical heat flux (CHF) enhancement, and also for the magnetic nanofluid. Since the magnetite nanoparticles can be controlled by an external magnetic field, the magnetic nanofluid is regarded as a controllable nanofluid, and thus, we can expect the advantages of magnetic nanofluid: 1) the nanoparticle suspension in nanofluid can be maintained by applying the alternating magnetic field, 2) the nanofluid concentration can be localized by applying the magnetic field for a region of interest and 3) the magnetite nanoparticles can be removed from magnetic nanofluid easily. In this study, we focused on the CHF characteristics of magnetic nanofluid in both pool boiling and flow boiling. The first part is for the pool boiling CHF of magnetic nanofluid. At atmospheric pressure, saturated pool boiling CHF experiments were conducted using Ni-Cr wire for magnetic nanofluid and the other nanofluids. Among the various nanofluids, magnetic nanofluid has the highest value of pool boiling CHF, and the enhancement ratio (with respect to the pure water) ranges from 170 to 240 percent. To elucidate the mechanism underlying the pool boiling CHF enhancement, three approaches were introduced: 1) scanning electron microscope (SEM) images were obtained to explain the pool boiling CHF enhancement mechanism due to the deposited nanoparticles, which is related to the surface wettability of the heat transfer surface, 2) ultra-high speed movie were taken and analyzed to observe the bubble dynamics at the heat transfer surface and 3) the strength of electricity-induced magnetic field neat the heat transfer surface were calculated to examine the effect of magnetic field on the pool boiling CHF. The second part is for the flow boiling CHF of magnetic nanofluid. A series of flow boiling CHF experiments were performed at atmospheric pressure and low mass flux conditions. Based on the experimental data, we conclude that the use of magnetic nanofluid improves the flow boiling CHF characteristics: the flow boiling CHF enhanced for the magnetic nanofluid. This is mainly due to the deposition of magnetite nanoparticles on the heat transfer surface, which results in the improvement of wettability and re-wetting characteristics. And we need enough time to ensure the nanoparticle deposition and the flow boiling CHF enhancement, when a nanofluid is used as a working fluid.
APA, Harvard, Vancouver, ISO, and other styles
9

Sunakoda, Katsuaki, Shin Morishita, Seiichi Takahashi, and Toshiyuki Hakata. "Development and Testing of Hybrid Magnetic Responsive Fluid for Vibration Damper." In ASME 2009 Pressure Vessels and Piping Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/pvp2009-77651.

Full text
Abstract:
A new intelligent fluid is studied and developed. Rheological characteristics of the developed fluid change rapidly and can be controlled in the presence of an applied magnetic field. The developed fluid is a hybrid type fluid, and it consists consisting of carbonyl irons and super fine magnetite. Average diameters of carbonyl iron and super fine magnetite are a size in the order of a few microns and about 10 nano-meters respectively. Special treatment is made by coating the surface of carbonyl iron with super fine magnetite. Physical properties such as dispersion stability and thixotropical characteristics are examined. Shearing stress and pressure drops of the new fluid flow are examined and evaluated by changing the strength of magnetic fields. A small capacity damper is made, and damping tests are performed using the new fluids and also commercial MR fluid. Dynamic properties of the damper are evaluated. As a result of a series of studies, the developed hybrid magnetic responsive fluid is expected to be used as an intelligent fluid.
APA, Harvard, Vancouver, ISO, and other styles
10

He, Quanguo, Lei Zeng, and Zhaohui Wu. "Magnetic Gold Film Fabrication from MPTES-functionlized Magnetite Nanoparticles." In 2010 International Conference on Measuring Technology and Mechatronics Automation (ICMTMA 2010). IEEE, 2010. http://dx.doi.org/10.1109/icmtma.2010.653.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Magnetite"

1

G. B. Cotten. Magnetic Separations with Magnetite: Theory, Operation, and Limitations. Office of Scientific and Technical Information (OSTI), August 2000. http://dx.doi.org/10.2172/765801.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Edward R. Torak and Peter J. Suardini. Bench-Scale Testing of the Micronized Magnetite Process. Office of Scientific and Technical Information (OSTI), November 1997. http://dx.doi.org/10.2172/2239.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Kochen, R. L. Actinide removal from aqueous solution with activated magnetite. Edited by R. L. Thomas. Office of Scientific and Technical Information (OSTI), August 1987. http://dx.doi.org/10.2172/6066984.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Kuster, K., C. M. Lesher, and M. G. Houlé. Geology and geochemistry of mafic and ultramafic bodies in the Shebandowan mine area, Wawa-Abitibi terrane: implications for Ni-Cu-(PGE) and Cr-(PGE) mineralization, Ontario and Quebec. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329394.

Full text
Abstract:
The Shebandowan Ni-Cu-(PGE) deposit occurs in the Shebandowan greenstone belt in the Wawa-Abitibi terrane. This deposit is one of a few economic Ni-Cu-(PGE) deposits in the Superior Province and one of a very few deposits worldwide that contains both Ni-Cu-(PGE) and Cr-(PGE) mineralization. The mafic-ultramafic successions in the area comprise abundant flows and sills of tholeiitic basalt and lesser Al-undepleted komatiite (MgO &amp;gt;18 wt%, Al2O3/TiO2 = 15-25), the latter indicating separation from mantle sources at shallow levels. Siliceous high-Mg basalts (MgO 8-12 wt%, SiO2 &amp;gt; 53 wt%, TiO2 &amp;lt; 1.2 wt%, La/Sm[MN] &amp;lt; 1-2) are relatively abundant in the area and likely represent crustally contaminated komatiites. Ultramafic bodies in the Shebandowan mine area comprise at least three or four komatiitic sills (A-B, C, D) and at least two komatiitic flows (E, F), all of which are altered to serpentinites or talc-carbonate schists with relict igneous chromite and rare relict igneous orthopyroxene-clinopyroxene. Unit A-B contains pentlandite-pyrrhotite-chalcopyrite-pyrite-magnetite mineralization, occurring as massive sulfides, sulfide breccias, or stringers, and subeconomic chromite mineralization in contorted massive bands varying from a few millimetres up to 10 metres thick. The localization of massive and semi-massive Ni-Cu-(PGE) ores along the margins of Unit A and the paucity of disseminated and net-textured ores suggest tectonic mobilization. Chromite is typically zoned with Cr-Mg-Al-rich (chromite) cores and Fe-rich (ferrichromite/magnetite) rims due to alteration and/or metamorphism, but rarely contains amoeboid magnetite cores. The thickness of chromite in Unit B is too great to have crystallized in cotectic proportion from the komatiitic magma and a model involving dynamic upgrading of magnetite xenoliths derived from interflow oxide facies iron formations is being tested.
APA, Harvard, Vancouver, ISO, and other styles
5

Huang, X. Magnetite chemistry of the supergiant Bayan Obo REE deposit, China. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/329176.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Thomas, M. D. Magnetic and gravity models, northern half of the Taltson Magmatic Zone, Rae Craton, Northwest Territories: insights into upper crustal structure. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/328244.

Full text
Abstract:
A prominent magnetic low along an eastern portion of the Paleoproterozoic Taltson magmatic zone (TMZ) correlates mainly with the youngest granitoid in the zone, the peraluminous ca. 1936 Ma Konth granite. Flanking belts of higher magnetic intensity coincide mainly with slightly older Taltson plutonic rocks (e.g. ca. 1986 Ma Deskenatlata granodiorite, ca. 1955 Ma Slave granite) to the west and Neoarchean and/or Paleoproterozic gneisses of the Rae Craton to the east. A prominent gravity low along a portion of the northeastern margin of the TMZ correlates mainly with the Konth granite. Modelling of east-west magnetic and gravity profiles crossing the TMZ is used to investigate the geometrical and geological significance of these signatures. Modelling of the gravity low revealed a basin-like shape, with a maximum thickness of 14.9 km, for a composite unit of Konth-Slave magmatic suites. Magnetic modelling, the preferred technique north and south of the gravity minimum, yielded basin-like shapes for an essentially nonmagnetic Konth-Slave unit, but with much smaller maximum thicknesses of 5.0 and 6.5 km, respectively. Farther south in the TMZ, strongly magnetic units within mapped Konth and Slave granites preclude definition of a nonmagnetic Konth-Slave unit. Aside from the Slave unit, most other modelled magnetic units are generally steep and narrow and have fairly large magnetic susceptibilities. They are modelled to a depth of 6.2 km below sea level and have a steeply dipping, near-surface structural fabric extending to significant depth. Granitoids in the TMZ have previously been designated as ilmenite series or magnetite series, but modelled susceptibilities indicate that revisions to some designations may be required.
APA, Harvard, Vancouver, ISO, and other styles
7

Ziemniak, S. E., M. E. Jones, and K. E. S. Combs. Magnetite solubility and phase stability in alkaline media at elevated temperatures. Office of Scientific and Technical Information (OSTI), May 1994. http://dx.doi.org/10.2172/34346.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Gandhi, S. S. Magnetite deposits in metasiltstones of the Snare Group at Hump Lake, Northwest Territories. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1992. http://dx.doi.org/10.4095/132866.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Sappin, A. A., and M G Houlé. The composition of magnetite in Archean mafic-ultramafic intrusions within the Superior Province. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2020. http://dx.doi.org/10.4095/326896.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Dare, S. Contribute expertise on magnetite (apatite) chemistry applied to IOA deposits (collaboration/workshops/ shortcourses). Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/329166.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Magnetite' for particular source types:
Journal articles Dissertations / Theses Books
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!

To the bibliography