scholarly journals The Effect of Tissue-Mimicking Phantom Compressibility on Magnetic Hyperthermia

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 803 ◽  
Author(s):  
Katarzyna Kaczmarek ◽  
Radosław Mrówczyński ◽  
Tomasz Hornowski ◽  
Rafał Bielas ◽  
Arkadiusz Józefczak
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Magnetic Materials ◽  
Absorption Rate ◽  
Magnetic Particles ◽  
Specific Absorption Rate ◽  
Magnetic Hyperthermia ◽  
Magnetic Losses ◽  
Small Temperature ◽  
Transmission Electron

During hyperthermia, magnetite nanoparticles placed in an AC magnetic field become a source of heat. It has been shown that in fluid suspensions, magnetic particles move freely and generate heat easily. However, in tissues of different mechanical properties, nanoparticle movement is limited and leads to a small temperature rise in tissue. Therefore, it is crucial to conduct magnetic hyperthermia experiments in similar conditions to the human body. The effect of tissue-mimicking phantom compressibility on the effectiveness of magnetic hyperthermia was investigated on agar phantoms. Single and cluster nanoparticles were synthesized and used as magnetic materials. The prepared magnetic materials were characterized by transmission electron microscopy (TEM), and zeta potential measurements. Results show that tissue-mimicking phantom compressibility decreases with the concentration of agar. Moreover, the lower the compressibility, the lower the thermal effect of magnetic hyperthermia. Specific absorption rate (SAR) values also proved our assumption that tissue-mimicking phantom compressibility affects magnetic losses in the alternating magnetic field (AMF).

scholarly journals Synthesis of Poly(N-vinylcaprolactam)-Grafted Magnetite Nanocomposites for Magnetic Hyperthermia

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
A. Morfin-Gutiérrez ◽  
H. Iván Meléndez-Ortiz ◽  
B. A. Puente-Urbina ◽  
L. A. García-Cerda
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Magnetic Hyperthermia ◽  
Heating Equipment ◽  
X Ray Diffraction ◽  
Hyperthermia Treatment ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Vibration Sample Magnetometry

In this study, the synthesis, characterization, and application of poly(N-vinylcaprolactam)-grafted magnetite nanocomposites for magnetic hyperthermia are reported. Superparamagnetic magnetite nanoparticles (MagNPs) with sizes in the range of 10–16 nm were synthesized by the coprecipitation method and then functionalized with vinyltrimethoxysilane (VTMS). MagNPs-VTMS coated with poly(N-vinylcaprolactam) (PNVCL) were prepared by free radical polymerization. The obtained materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibration sample magnetometry (VSM), and Fourier transform infrared spectroscopy (FT-IR). The heating ability was evaluated under a magnetic field using a solid state induction heating equipment at 10.2 kA/m and 362 kHz. The MagNPs-PNVCL nanocomposites showed a behavior close to superparamagnetic materials, which is appropriated for magnetic hyperthermia treatment; in concentrations of 8 mg/mL, they were able to heat up, increasing the temperature up to 42°C in a period of time lower than 10 minutes.

Fe2O3 nanoparticles for magnetic hyperthermia applications

2015 ◽  
Vol 1779 ◽  
pp. 7-13 ◽  
Author(s):  
O M Lemine ◽  
Karim Omri ◽  
L El Mir ◽  
V Velasco ◽  
Patricia Crespo ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Magnetic Hyperthermia ◽  
Fe2o3 Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heating Efficiency ◽  
Hall Method

ABSTRACTSynthesis, structural, magnetic properties and heating efficiency of γ-Fe2O3 nanoparticles have been investigated. X-ray diffraction (XRD) and Mössbauer spectroscopy show that the obtained nanoparticles are mainly composed of maghemite phase (γ-Fe2O3). Williamson-Hall method shows that the crystallite is around 14nm.The specific absorption rate (SAR) under an alternating magnetic field is investigated as a function of frequency. A highest SAR value of 12W/g for frequency 523 kHz was obtained.

Fabrication and characterization of highly textured (Bi,Pb)2Sr2Ca2Cu3Ox superconducting ceramics using high magnetic field and cold isostatic pressing

1995 ◽  
Vol 10 (10) ◽  
pp. 2433-2443 ◽  
Author(s):  
Wai Lo ◽  
R. Stevens ◽  
R. Doyle ◽  
A.M. Campbell ◽  
W.Y. Liang
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Cold Isostatic Pressing ◽  
Sintered Ceramic ◽  
Grain Alignment ◽  
Isostatic Pressing ◽  
Transmission Electron ◽  
Superconducting Ceramics ◽  
High Degree

High textured (Bi,Pb)2Sr2Ca2Cu3Ox ceramics have been fabricated by aligning deflocculated flakes of (Bi,Pb)2Sr2Ca2Cu3Ox suspended in an organic medium by means of a high de magnetic field (6 T) at room temperature followed by cold isostatic pressing. The proportion of the (Bi,Pb)2Sr2Ca2Cu3Ox phase in the precursor powder was carefully controlled, and the characteristics of the powder, such as size distribution and morphology, were determined. A high degree of grain alignment was found in the specimens after the magnetic alignment, although the bulk density of the materials was low. Cold isostatic pressing substantially increased the density of the magnetically prealigned specimens which also resulted in a slight decrease in the degree of grain alignment. This minor realignment was found to be due to the various kinds of processing defects that appeared in the specimens during compaction due to the grinding and cracking of the grains and their interlocking. The microstructural and superconducting properties of the sintered ceramic have been studied using texture goniometry, high resolution scanning electron microscopy, transmission electron microscopy, ac magnetic susceptometry, and critical current measurements.

scholarly journals Effect of Alternating Magnetic Field on the Fatigue Behaviour of EN8 Steel and 2014-T6 Aluminium Alloy

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 984 ◽  
Author(s):  
Akram ◽  
Babutskyi ◽  
Chrysanthou ◽  
Montalvão ◽  
Pizurova
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Fatigue Behaviour ◽  
Alternating Magnetic Field ◽  
X Ray Diffraction ◽  
Secondary Precipitation ◽  
Transmission Electron ◽  
Fatigue Endurance ◽  
Fracture Features ◽  
Compressive Residual Stresses

The application of an alternating magnetic field (0.54 T) was observed to lead to an improvement in the fatigue endurance and an increase in Vickers microhardness and tensile strength of both EN8 steel and AA2014-T6 alloy. Fractography using scanning electron microscopy showed evidence of more ductile fracture features after treatment in contrast to untreated samples. The results of X-ray diffraction indicated formation of more compressive residual stresses following treatment; while examination by transmission electron microscopy showed evidence of fewer dislocations. In the case of the AA2014-T6 alloy; Guinier-Preston (GP) zones were also generated by the alternating magnetic field. However; the temperature increase during the treatment was too low to explain these observations. The results were attributed to the non-thermal effect of the alternating magnetic field treatment that led to depinning and movement of dislocations and secondary precipitation of copper.

Superconductivity of Dc Reactive Magnetron Sputtered Epitaxial TiN/NbN Superlattices

1992 ◽  
Vol 275 ◽  
Author(s):  
M. Shinn ◽  
B. -S. Hong ◽  
S. A. Barnett
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Film Surface ◽  
Wavelength Dependence ◽  
Reactive Magnetron ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

ABSTRACTEpitaxial B1-structure TiN/NbN superlattices have been grown by reactive magnetron sputtering On MgO(001). X-ray diffraction and transmission electron microscopy (TEM) diffraction spectra exhibited up to nine orders of superlattice reflections, indicating that the superlattice interfaces were relatively sharp. TEM images also showed well-defined layers. The superlattice wavelength (∧) dependence of the superconducting transition temperature (Tc), critical Current density (Jc), and electrical resistivity (ρ) have been investigated. Tc values increased from 12 K to 17 K with increasing ∧. Jc in a magnetic field perpendicular to the film surface ranged from 104 to 106 A/cm2, increasing with increasing wavelength and decreasing with increasing applied magnetic field. Jc in a field parallel to the film surface was > 10 times higher, ≈ 107 A/cm2. The resistivity exhibited different ∧ dependencies in three different A ranges.

scholarly journals Effect of A Superstrate on On-Head Matched Antennas for Biomedical Applications

Electronics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1099
Author(s):  
Md Rokunuzzaman Robel ◽  
Asif Ahmed ◽  
Akram Alomainy ◽  
Wayne S. T. Rowe
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Performance Improvement ◽  
Direct Contact ◽  
Biomedical Applications ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Conducting Layer ◽  
Electric And Magnetic Field ◽  
Biomedical Diagnosis

The effect of using a superstrate dielectric layer on an on-head matched antenna for biomedical diagnosis applications is investigated. Two on-head matched antennas are considered with different length meandered lines ensuring operation around 0.9 GHz frequency. The first antenna’s conductive radiating structure is in direct contact with the head phantom, whereas the second one utilises a 0.5 mm thick superstrate layer on top of the conducting layer as a buffer. The lateral dimensions of both antennas are held constant at 30 × 30 mm2. The electric and magnetic field distribution is analysed and the power penetration, 50 mm inside the head phantom, is derived from the electromagnetic field surrounding the antennas. Both homogeneous and inhomogeneous head phantoms are considered while evaluating the antennas in terms of their reflection coefficient, current distribution, electric field, magnetic field, specific absorption rate (SAR) and power penetration inside the head. The antennas are fabricated and measured utilizing an inhomogeneous phantom to validate the proposed performance improvement using a superstrate. It is shown that the superstrate antenna achieves a ~8 dB increase in power penetration inside the head phantom along with a 0.0731 W/kg decrease in SAR compared to the antenna without a superstrate.

Magnetic cluster developement in In1−x MnxSb semiconductor alloys

Open Physics ◽  
2010 ◽  
Vol 8 (4) ◽  
Author(s):  
Lidia Rednic ◽  
Iosif Deac ◽  
Eugen Dorolti ◽  
Marin Coldea ◽  
Vasile Rednic ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Magnetic Measurements ◽  
Semiconductor Alloys ◽  
X Ray Diffraction ◽  
Magnetic Cluster ◽  
X Ray ◽  
Small Magnetic Field ◽  
Transmission Electron

AbstractX-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM) and magnetic measurements as a function of applied magnetic field and temperature for In1−x MnxSb (0.05≤x≤0.2) system are reported. Magnetic measurements performed at high and small magnetic field in ZFC and FC indicate the coexistence of ferromagnetic In1−x MnxSb solid solution and two types of magnetic cluster: ferromagnetic MnSb and ferrimagnetic Mn2Sb. XPS valence band and Mn 2p core level spectra have confirmed the presence of MnSb and Mn2Sb phases. TEM images show some manganese antimonide phase microinclusions with dimension between (30–40) nm.

FABRICATION, ASSEMBLY AND MAGNETIC PROPERTIES OF NICKEL HOLLOW NANOBALLS

2006 ◽  
Vol 20 (10) ◽  
pp. 549-555 ◽  
Author(s):  
JUN WANG ◽  
YUEJIN ZHU ◽  
YEJUN WU ◽  
CHANGJUN WU ◽  
DONGFENG XU ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Strong Interaction ◽  
Nickel Nanoparticles ◽  
Transmission Electron ◽  
Metallic Cations ◽  
Self Assembled ◽  
Hollow Metal

Nanoshells composed of close-packed nickel nanoparticles have been fabricated on sillca spheres via strong interaction between the metallic cations and ions of the support. The nickel hollow nanoballs can be self-assembled via magnetic field-assisted route, which is confirmed by the transmission electron microscopy. The magnetic properties of Ni nanoshells are discussed. It is expected that the prepared method can be extended to the synthesis of other hollow metal spheres.

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