Room Temperature Initiated and Self-Heating Polymerization via Concentrated Emulsions: Application to Acrylonitrile Based Polymers *

2019 ◽  
pp. 298-305 ◽  
Author(s):  
Eli Ruckenstein ◽  
Hangquan Li
Keyword(s):  
Room Temperature ◽  
Self Heating ◽  
Concentrated Emulsions

Structural, Morphological, Magnetic and Self-Heating Studies of One-Step Polyol Synthesized Manganese Ferrite (MnFe2O4) Nanoparticles

2019 ◽  
Vol 19 (01) ◽  
pp. 1950003
Author(s):  
P. R. Ghutepatil ◽  
S. H. Pawar
Keyword(s):  
Room Temperature ◽  
Synthesis Method ◽  
Average Crystallite Size ◽  
Superparamagnetic Nanoparticles ◽  
Polyol Synthesis ◽  
X Ray Diffraction ◽  
Self Heating ◽  
Transmission Electron ◽  
One Step ◽  
Mnfe2o4 Nanoparticles

In this paper, uniform and superparamagnetic nanoparticles have been prepared using one-step polyol synthesis method. Structural, morphological and magnetic properties of obtained MnFe2O4 nanoparticles have been investigated by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA) techniques. Structural investigation showed that the average crystallite size of obtained nanoparticles was about 10[Formula: see text]nm. Magnetic study revealed that the nanoparticles were superparamagnetic at room temperature with magnetization 67[Formula: see text]emu/g at room temperature. The self-heating characteristics of synthesized MnFe2O4 nanoparticles were studied by applying external AC magnetic field of 167.6 to 335.2[Formula: see text]Oe at a fixed frequency of 265[Formula: see text]kHz. The SAR values of MnFe2O4 nanoparticles were calculated for 2, 5, 10[Formula: see text]mg[Formula: see text]mL[Formula: see text] concentrations and it is observed that the threshold hyperthermia temperature is achieved for all concentrations.

Thermal Characterization of Cu/CoFe Multilayer for Giant Magnetoresistive (GMR) Head Applications

2004 ◽  
Author(s):  
Y. Yang ◽  
M. Asheghi
Keyword(s):  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Boltzmann Transport Equation ◽  
Thermal Characterization ◽  
Disk Drive ◽  
Boltzmann Transport ◽  
Self Heating ◽  
Superlattice Structure ◽  
Metallic Ferromagnet

Giant Magnetoresistance (GMR) head technology is one of the latest advancement in hard disk drive (HDD) storage industry. The GMR head superlattice structure consists of alternating layers of extremely thin metallic ferromagnet and paramagnet films. A large decrease in the resistivity from antiparallel to parallel alignment of the film magnetizations can be observed, known as giant magnetoresistance (GMR) effect. The present work characterizes the in-plane electrical and thermal conductivities of Cu/CoFe GMR multilayer structure in the temperature range of 50 K to 340 K using Joule-heating and electrical resistance thermometry in suspended bridges. The thermal conductivity of the GMR layer monotonously increased from 25 Wm−1K−1 (at 55 K) to nearly 50 Wm−1K−1 (at room temperature). We also report the GMR ratio of 17% and a large negative magnetothermal resistance effect (GMTR) of 33% in Cu/CoFe superlattice structure. The Boltzmann transport equation (BTE) is used to estimate the GMR ratio, and to investigate the effect of repeats, as well as the spin-dependent interface and boundary scatting on the transport properties of the GMR structure. Aside from the interesting underlying physics, these data can be used in the predictions of the Electrostatic Discharge (ESD) failure and self-heating in GMR heads.

scholarly journals Rapid determination of the high cycle fatigue properties of high temperature aeronautical alloys by self-heating measurements

2018 ◽  
Vol 165 ◽  
pp. 22022
Author(s):  
Vincent Roué ◽  
Cédric Doudard ◽  
Sylvain Calloch ◽  
Frédéric Montel ◽  
Quentin Pujol D’Andrebo ◽  
...  
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
High Cycle Fatigue ◽  
Rapid Determination ◽  
The Self ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Heating Method ◽  
Self Heating

The determination of high cycle fatigue (HCF) properties of a material with standard method requires a lot of specimens, and could be really time consuming. The self-heating method has been developed in order to predict S–N–P curves (i.e., amplitude stress – number of cycles to failure – probability of failure) with only a few specimens. So the time-saving advantage of this method has been demonstrated on several materials, at room temperature. In order to reduce the cost and time of fatigue characterization at high temperature, the self-heating method is adapted to characterize HCF properties of a titanium alloy, the Ti-6Al-4V (TA6V), at different temperatures. So the self-heating procedure is adjusted to conduct tests with a furnace. Two dissipative phenomena can be observed on self-heating curves. Because of this, a two-scale probabilistic model with two dissipative mechanisms is used to describe them. The first one is observed for low amplitudes of cyclic loading, under the fatigue limit, and the second one for higher amplitudes where the mechanisms of fatigue damage are activated and are dissipating more energy. This model was developed on steel at room temperature. Even so, it is used to describe the self-heating curves of the TA6V at several temperatures.

Reliability Studies on Ge High Density Interconnect (Hdi) Modules

1993 ◽  
Vol 323 ◽  
Author(s):  
Kyung W. Paik ◽  
Edward S. Bernard
Keyword(s):  
Room Temperature ◽  
Temperature Cycling ◽  
Reliability Test ◽  
Reliability Testing ◽  
Self Heating ◽  
Power Cycling ◽  
Study Results ◽  
Beam Bending ◽  
Residual Stress Analysis ◽  
Cycling Temperature

ABSTRACTConsiderable mechanical and environmental reliability testing as defined by MIL-STD-883 has been performed on GE HDI modules in both hermetic and nonhermetic configurations. The tests involving temperature cycling, temperature bakes, thermal shock, power cycling by self-heating, vibration, centrifuge and drop shock showed no change in the overlay or in the performance of the underlaying chips on the substrate. As an additional reliability test, the effect of humidity cycling (45° - 95° relative humidity) on nonhermetic HDI substrates has been also investigated. Any noticeable failures and degradation of metallization were not observed by humidity cycling itself at room temperature. Both the 883 and humidity cycling test could lead to the conclusion that HDI is a robust MCM-D technology. In addition, extensive studies on the residual stress analysis of the thin film layers of metal and polymer during fabrication and thermal cycling have been performed using the Flexus laser beam bending instrument. The study results predicted that failure of overlay HDI such as delamination between layers is less likely because of lower in-plane stresses than in conventional spin-coated and cured polyimide.

scholarly journals On the Influence of Ultrasonic Surface Mechanical Attrition Treatment (SMAT) on the Fatigue Behavior of the 304L Austenitic Stainless Steel

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 100 ◽  
Author(s):  
Clément Dureau ◽  
Marc Novelli ◽  
Mandana Arzaghi ◽  
Roxane Massion ◽  
Philippe Bocher ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Fatigue Limit ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
High Stress ◽  
Fatigue Tests ◽  
Surface Mechanical Attrition Treatment ◽  
Self Heating ◽  
Mechanical Attrition

The potential of ultrasonic surface mechanical attrition treatment (SMAT) at different temperatures (including cryogenic) for improving the fatigue performance of 304L austenitic stainless steel is evaluated along with the effect of the fatigue loading conditions. Processing parameters such as the vibration amplitude, the size, and the material of the shot medias were fixed. Treatments of 20 min at room temperature and cryogenic temperature were compared to the untreated material by performing rotating–bending fatigue tests at 10 Hz. The fatigue limit was increased by approximately 30% for both peening temperatures. Meanwhile, samples treated for 60 min at room temperature were compared to the initial state in uniaxial fatigue tests performed at R = −1 (fully reversed tension–compression) at 10 Hz, and the fatigue limit enhancement was approximately 20%. In addition, the temperature measurements done during the tests revealed a negligible self-heating (∆t < 50 °C) of the run-out specimens, whereas, at high stress amplitudes, temperature changes as high as 300 °C were measured. SMAT was able to increase the stress range for which no significant local self-heating was reported on the surface.

scholarly journals Carbon source self-heating: ultrafast, energy-efficient and room temperature synthesis of highly fluorescent N, S-codoped carbon dots for quantitative detection of Fe(iii) ions in biological samples

2020 ◽  
Vol 2 (4) ◽  
pp. 1483-1492 ◽  
Author(s):  
Honggang Yin ◽  
Die Gao ◽  
Yan Qiu ◽  
Gaoyi Yi ◽  
Jun Li ◽  
...  
Keyword(s):  
Detection Limit ◽  
Carbon Source ◽  
Carbon Dots ◽  
Energy Efficient ◽  
Room Temperature ◽  
Quantitative Detection ◽  
Temperature Synthesis ◽  
Self Heating ◽  
Wide Range ◽  
Scalable Synthesis

A novel carbon source self-heating strategy for ultrafast, energy-efficient and scalable synthesis of highly PL N, S-codoped CDs was established and used for sensing Fe3+ in an ultra-wide range of 0.2–600 μM, with a detection limit of 0.10 μM.

scholarly journals Влияние саморазогрева на модуляционные характеристики микродискового лазера

2020 ◽  
Vol 46 (11) ◽  
pp. 3
Author(s):  
А.Е. Жуков ◽  
Э.И. Моисеев ◽  
А.М. Надточий ◽  
Н.В. Крыжановская ◽  
М.М. Кулагина ◽  
...  
Keyword(s):  
Room Temperature ◽  
Modulation Frequency ◽  
Small Diameter ◽  
Thermal Stabilization ◽  
The Self ◽  
Maximum Speed ◽  
Modulation Bandwidth ◽  
Heating Effect ◽  
Self Heating ◽  
High Bias

The performance of quantum dot microdisk lasers operating at room temperature without thermal stabilization was experimentally investigated, and the highest modulation bandwidth of microdisks of various diameters was calculated. It is shown that taking into account the self-heating effect of the microlaser at high bias currents, which manifests itself in a decrease in the maximum modulation frequency and in an increase in the current at which the maximum speed is reached, allows us to describe the experimental data well. Self-heating effect has the greatest impact on microlasers of small diameter (less than 20 µm).

Sign in / Sign up

Export Citation Format

Share Document