Temperature Dependence of the FMR Spectra of Polymer Composites with Nanocrystalline α-Fe/C Filler

2007 ◽  
Vol 128 ◽  
pp. 213-218 ◽  
Author(s):  
N. Guskos ◽  
M. Maryniak ◽  
J. Typek ◽  
Iwona Pełech ◽  
Urszula Narkiewicz ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Temperature Dependence ◽  
Nanocrystalline Material ◽  
Magnetic Interactions ◽  
Benzene Rings ◽  
The Matrix ◽  
Nanocrystalline Iron ◽  
The Right ◽  
Ether Ester

Two different concentrations of nanocrystalline material: α-Fe/C were prepared by the carburization of nanocrystalline iron and characterized by XRD and SEM. The nanoparticles were next used as fillers in polymer nanocomposites using the in situ polycondensation reaction in a poly(ether-ester) matrix with two concentrations: 0.1 wt. % and 0.3 wt. %. The temperature dependence of the ferromagnetic resonance (FMR) spectra was investigated to study magnetic interactions in the compounds. The introduced FMR parameters (intensity and position of the right peak) describe well the temperature dependence of FMR spectra of strongly interacting magnetic nanoparticles. The FMR spectra depend strongly on the concentration of magnetic nanoparticles, which influence the magnetic interactions between them. Two main critical points of the matrix (the glass state and the freezing of benzene rings) influence the behaviour of the FMR spectra.

Magnetic Properties of γ-Fe2O3/Poly(Ether-Ester) Nanocomposites

2008 ◽  
Vol 8 (4) ◽  
pp. 2127-2134 ◽  
Author(s):  
N. Guskos ◽  
V. Likodimos ◽  
S. Glenis ◽  
M. Maryniak ◽  
M. Baran ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Magnetic Behavior ◽  
Thermoplastic Elastomer ◽  
Relaxation Processes ◽  
Close Correspondence ◽  
Polycondensation Reaction ◽  
Dispersion State ◽  
Ether Ester

The magnetic properties of γ-Fe2O3 nanoparticles embedded in a thermoplastic elastomer poly(ether-ester) copolymer by the in situ polycondensation reaction process have been investigated by means of magnetization and ferromagnetic resonance (FMR) measurements at low filler concentrations of 0.1 and 0.3 wt% with the magnetic additive introduced in the polymer matrix in powder and solution form. The magnetic behavior of the magnetopolymeric nanocomposites indicates significant interparticle interaction effects that depend mainly on the dispersion state of the magnetic nanoparticles as well as their concentration, consistent with the variation of the particle microstructure characterized by magnetic aggregates in the nanometer and micron scale for the solution and powder dispersions, respectively. The magnetization and FMR results at different filler concentrations and dispersions showa close correspondence to the relaxation processes of the copolymer, implying the coupling of polymeric and magnetic properties.

The Mechanical Properties of Near-equiatomic B2/f.c.c. FeNiMnAl Alloys

2013 ◽  
Vol 1516 ◽  
pp. 249-254 ◽  
Author(s):  
Xiaolan Wu ◽  
Ian Baker ◽  
Hong Wu ◽  
Paul R. Munroe
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Temperature Dependence ◽  
Orientation Relationship ◽  
Annealing Time ◽  
Two Phase ◽  
Chemical Partitioning ◽  
The Matrix ◽  
In Situ Heating

ABSTRACTTwo types of as-cast microstructures have been observed in a series of near-equiatomic FeNiMnAl alloys: 1) an ultrafine microstructure in Fe30Ni20Mn20Al30 [1] and Fe25Ni25Mn20Al30, which consists of (Fe, Mn)-rich B2-ordered (ordered b.c.c.) and (Ni, Al)-rich L21-ordered (Heusler) phases aligned along <100>; and 2) a fine two-phase microstructure in Fe30Ni20Mn30Al20 and Fe25Ni25Mn30Al20, which consists of alternating (Fe, Mn)-rich f.c.c. and (Ni, Al)-rich B2-ordered platelets with an orientation relationship close to f.c.c (002) // B2 (002); f.c.c. [011] // B2 [001] [2]. The phases in Fe25Ni25Mn20Al30 coarsened upon annealing with no significant change in the chemical partitioning. The hardness behavior was studied as a function of the annealing time at 823 K. AnL21-to-B2 transition, which occurred at 573-623K, was observed using in-situ heating in a TEM. After annealing at 973 K for 100 h, needle-shaped clusters of (Fe, Mn)-rich precipitates were observed along the grain boundaries and in the matrix. The temperature dependence of the yield strength of as-cast Fe25Ni25Mn20Al30 was also studied.

Temperature Dependence of Double Shockley Stacking Fault Behavior in Nitrogen-Doped 4h-Sic Studied by In-Situ Synchrotron X-Ray Topography

2020 ◽  
Author(s):  
Fumihiro Fujie ◽  
Shunta Harada ◽  
Kenji Hanada ◽  
Hiromasa Suo ◽  
Haruhiko Koizumi ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Stacking Fault ◽  
X Ray ◽  
Nitrogen Doped ◽  
Fault Behavior

scholarly journals Supramolecular ionic polymer/carbon nanotube composite hydrogels with enhanced electromechanical performance

2020 ◽  
Vol 9 (1) ◽  
pp. 478-488 ◽  
Author(s):  
Yun-Fei Zhang ◽  
Fei-Peng Du ◽  
Ling Chen ◽  
Ka-Wai Yeung ◽  
Yuqing Dong ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Ion Mobility ◽  
Artificial Muscles ◽  
Ionic Polymer ◽  
Composite Hydrogels ◽  
The Matrix ◽  
Electromechanical Performance ◽  
Carbon Nanotube Composite ◽  
Robotic Devices

AbstractElectroactive hydrogels have received increasing attention due to the possibility of being used in biomimetics, such as for soft robotics and artificial muscles. However, the applications are hindered by the poor mechanical properties and slow response time. To address these issues, in this study, supramolecular ionic polymer–carbon nanotube (SIPC) composite hydrogels were fabricated via in situ free radical polymerization. The polymer matrix consisted of carbon nanotubes (CNTs), styrene sulfonic sodium (SSNa), β-cyclodextrin (β-CD)-grafted acrylamide, and ferrocene (Fc)-grafted acrylamide, with the incorporation of SSNa serving as the ionic source. On applying an external voltage, the ions accumulate on one side of the matrix, leading to localized swelling and bending of the structure. Therefore, a controllable and reversible actuation can be achieved by changing the applied voltage. The tensile strength of the SIPC was improved by over 300%, from 12 to 49 kPa, due to the reinforcement effect of the CNTs and the supramolecular host–guest interactions between the β-CD and Fc moieties. The inclusion of CNTs not only improved the tensile properties but also enhanced the ion mobility, which lead to a faster electromechanical response. The presented electro-responsive composite hydrogel shows a high potential for the development of robotic devices and soft smart components for sensing and actuating applications.

scholarly journals In situ structure and organization of the influenza C virus surface glycoprotein

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Steinar Halldorsson ◽  
Kasim Sader ◽  
Jack Turner ◽  
Lesley J. Calder ◽  
Peter B. Rosenthal
Keyword(s):  
Membrane Fusion ◽  
Hexagonal Lattice ◽  
Surface Glycoprotein ◽  
Structural Basis ◽  
Virus Surface ◽  
The Matrix ◽  
Influenza C Virus ◽  
Subtomogram Averaging ◽  
Electron Cryotomography

AbstractThe lipid-enveloped influenza C virus contains a single surface glycoprotein, the haemagglutinin-esterase-fusion (HEF) protein, that mediates receptor binding, receptor destruction, and membrane fusion at the low pH of the endosome. Here we apply electron cryotomography and subtomogram averaging to describe the structural basis for hexagonal lattice formation by HEF on the viral surface. The conformation of the glycoprotein in situ is distinct from the structure of the isolated trimeric ectodomain, showing that a splaying of the membrane distal domains is required to mediate contacts that form the lattice. The splaying of these domains is also coupled to changes in the structure of the stem region which is involved in membrane fusion, thereby linking HEF’s membrane fusion conformation with its assembly on the virus surface. The glycoprotein lattice can form independent of other virion components but we show a major role for the matrix layer in particle formation.

In situ deposition of magnetic nanoparticles on glass mat using plasma sputtering method

2021 ◽  
pp. 1-11
Author(s):  
Sheila Shahidi ◽  
Sanaz Dalalsharifi ◽  
Mahmood Ghoranneviss ◽  
Rattanaphol Mongkholrattanasit
Keyword(s):  
Magnetic Nanoparticles ◽  
Plasma Sputtering ◽  
In Situ Deposition ◽  
Glass Mat

scholarly journals EXPRESS: Chronic thromboembolic pulmonary hypertension following pulmonary embolism with a right ventricular thrombus: A report of two cases

2021 ◽  
pp. 204589402110136
Author(s):  
Tailong Zhang ◽  
Weitao Liang ◽  
Longrong Bian ◽  
Zhong Wu
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Imaging Features ◽  
Pulmonary Endarterectomy ◽  
Right Heart ◽  
Thromboembolic Pulmonary Hypertension ◽  
The Right ◽  
Cardiac Masses

Right heart thrombus (RHT) accompanied by chronic thromboembolic pulmonary hypertension (CTEPH) is a rare entity. RHT may develop in the peripheral veins or in situ within the right heart chambers. The diagnosis of RHT is challenging, since its symptoms are typically non-specific and its imaging features resemble those of cardiac masses. Here, we report two cases of RHT with CTEPH that presented as right ventricular masses initially. Both patients underwent simultaneous pulmonary endarterectomy (PEA) and resection of the ventricular thrombi. Thus, when mass-like features are confirmed by imaging, RHT should be suspected in patients with CTEPH, and simultaneous RHT resection is required along with PEA.

A Neo-Assyrian statue from Til Barsib

Iraq ◽  
1996 ◽  
Vol 58 ◽  
pp. 79-87
Author(s):  
Arlette Roobaert
Keyword(s):  
Iron Age ◽  
Lower Portion ◽  
Maximum Height ◽  
Clear Indication ◽  
Large Hole ◽  
Relative Placement ◽  
The Right ◽  
As If ◽  
Medium Texture

During the 1993 season of excavations at Tell Ahmar, three pieces of a life-size basalt statue were found in a pit dug into one of the large walls surrounding an Iron Age vaulted tomb (Fig. 1). The head, the tors o and the lower part fitted together perfectly. When correctly assembled, these three pieces formed the figure of a standing beardless man with clasped hands (Fig. 2a−b). Only the feet were missing. The maximum height of the reconstructed statue is 1.45m. It was clear from the damage to portions of its body that the statue had been deliberately broken in antiquity. Details, such as a large hole on the right side of the chest, a smaller one on the top of the head and, above all, the defacement of the head suggest that the statue may have actually been “killed”.All three pieces of the statue, which was carved out of a blue greyish basalt of medium texture, were found lying on their backs (Fig. 4). The head lay next to the lower part of the statue, but was buried in a slightly deeper position. The relative placement of these fragments seems to be a clear indication that the statue was not knocked down at this particular spot, but was brought to this location in separate pieces, perhaps with the deliberate intention of burying them.The head was cut off as if the statue had been decapitated. The torso was separated from the lower portion of the statue by an oblique cut that divided the figure just below the waist. The cut runs downwards from the back and continues underneath the clasped hands at the front, leaving the hands almost completely undamaged. The lower part of the statue seems to have been separated from the missing feet by a horizontal cut. This may indicate that the base of the statue was left in situ, probably because it was solidly set in the ground.

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