Optimized nanomagnetic system for spintronic applications

2013 ◽  
Vol 1617 ◽  
pp. 193-197
Author(s):  
Mishel Morales Meza ◽  
Paul P. Horley ◽  
Alexander Sukhov
Keyword(s):  
Magnetic Particles ◽  
Magnetic System ◽  
High Sensitivity ◽  
Large Degree ◽  
Dipole Interaction ◽  
Fine Tuning ◽  
Nano Particles ◽  
Spintronic Devices ◽  
Ordered Arrays ◽  
New Phenomena

ABSTRACTMagnetic properties at nano-scale provide a whole spectrum of new phenomena that can be beneficial for spintronic devices characterized with ultra-short response time, high sensitivity to magnetic field and miniature size. The properties and stability of a magnetic system can be enhanced by creating ordered arrays of ferromagnetic nano-particles. Here we report a considerable reduction of coercitivity for a magnetic array using triangular, square and hexagonal particle arrangement. The reduction of coercitivity can be explained by fine-tuning of dipole-dipole interaction between magnetic particles, which is to large degree influenced by the number of nearest neighbors and distance between the particles.

Recent Progress in the Analysis of Captopril Using Electrochemical Methods: A Review

2019 ◽  
Vol 15 (3) ◽  
pp. 198-206 ◽  
Author(s):  
Sarfaraz Ahmed Mahesar ◽  
Saeed Ahmed Lakho ◽  
Syed Tufail Hussain Sherazi ◽  
Hamid Ali Kazi ◽  
Kamran Ahmed Abro ◽  
...  
Keyword(s):  
Enzyme Inhibitor ◽  
Modified Electrodes ◽  
High Sensitivity ◽  
Pharmaceutical Formulations ◽  
Inorganic Materials ◽  
Electrochemical Methods ◽  
Nano Particles ◽  
Moderate Heart Failure ◽  
Analytical Instrumentation

Background: Captopril is the synthetic dipeptide used as an angiotensin converting enzyme inhibitor. Captopril is used to treat hypertension as well as for the treatment of moderate heart failure. Analytical instrumentation and methodology plays an important role in pharmaceutical analysis. Methods: This review presents some important applications of electrochemical modes used for the analysis of captopril. So far captopril has been analyzed by using different bare and modified working electrodes with a variety of modifiers from organic and inorganic materials to various types of nano particles/materials. Results: This paper presents some of the methods which have been published in the last few years i.e. from 2003 to 2016. This review highlights the role of the analytical instrumentation, particularly electrochemical methods in assessing captopril using various working electrodes. Conclusion: A large number of studies on voltammetry noted by means of various bare and modified electrodes. Among all of the published voltammetric methods, DPV, SWV, CV and miscellaneous modes were trendy techniques used to analyze captopril in pharmaceutical formulations as well as biological samples. Electrodes modified with nanomaterials are promising sensing tools as this showed high sensitivity, good accuracy with precision as well as selectivity. In comparison to chromatographic methods, the main advantages of electrochemical methods are its cheaper instrumentation, lower detection limit and minimal or no sample preparation.

scholarly journals Effect of transient processes on the switching stability of dc machines

2018 ◽  
Vol 239 ◽  
pp. 01036 ◽  
Author(s):  
Viktor Kharlamov ◽  
Pavel Shkodun ◽  
Andrey Ognevsky
Keyword(s):  
Magnetic System ◽  
Significant Proportion ◽  
Electrical Energy ◽  
Operating Conditions ◽  
Fine Tuning ◽  
Transient Processes ◽  
Rolling Stock ◽  
Electric Motors ◽  
Electric Rolling Stock ◽  
Switching Stability

Effective use of fuel and energy resources is one of the main tasks in modern industry and transport. The main directions of increasing the energy efficiency of the electric rolling stock of railways are considered in the paper. For the electric rolling stock of railways, a significant proportion of electric power consumption falls on traction needs. The consumption of electrical energy and its recovery directly depends on the proper operation and fine-tuning of the magnetic system and switching of traction electric motors of the rolling stock. The methods of testing traction electric motors currently used in railway transport do not fully correspond to their operating modes during operation. For more reliable control of their condition, a methodology for estimating the nature of the operation of traction electric motors in conditions close to real ones was proposed. Studies of the influence of transient processes on the quality of switching of traction electric motors taking into account operating conditions are carried out. Based on the results of the study, the analysis of the data obtained is carried out, and a criterion for estimating the switching stability of traction electric motors in transient operation modes is proposed. The proposed criterion allows carrying out quality control of the tuning of the magnetic system and switching of the traction electric motor, and also estimating the nature of its operation in various modes, taking into account the operating conditions.

SYNTHESIS AND MANIPULATION OF WO3 NANO PARTICLES FOR GAS SENSING APPLICATIONS

2012 ◽  
Vol 05 ◽  
pp. 227-233
Author(s):  
Elham kamali Heidari ◽  
Seyed Reza Mahmoodi ◽  
Ehsan Marzbanrad ◽  
Babak Raisi ◽  
Cyrus Zmani
Keyword(s):  
Gas Sensing ◽  
Average Particle Size ◽  
High Sensitivity ◽  
Nano Particles ◽  
Average Particle ◽  
Monoclinic Structure ◽  
Template Removal ◽  
Sensing Applications ◽  
Low Concentrations ◽  
Nanocasting Route

Ultra fine WO 3 nanoparticles were synthesized by nanocasting route, using mesoporous SiO 2 as a template. BET measurements showed a specific surface area of 700m2/gr for synthesized SiO 2 while after impregnation and template removal, this area was reduced to 43m2/gr for WO 3 nanoparticles. HRTEM results showed single crystalline nanoparticles with average particle size of about 5nm possessing a monoclinic structure which is the favorite crystal structure for gas sensing applications. Alternative electric field was applied to align synthesized WO 3 nanoparticles between electrodes. Gas sensing measurements showed that this material has a high sensitivity to very low concentrations of NO 2 at 250°C.

Fine structure of the spectra of magnetic particles in the vortex state and their ordered arrays

2007 ◽  
Vol 71 (11) ◽  
pp. 1494-1496
Author(s):  
B. A. Ivanov ◽  
P. V. Bondarenko ◽  
A. Yu. Galkin ◽  
C. E. Zaspel ◽  
D. D. Sheka
Keyword(s):  
Fine Structure ◽  
Magnetic Particles ◽  
Vortex State ◽  
Ordered Arrays

Nano-Design of Oxide Particles and Electrode Structure for High Sensitivity NO2 Sensor Using WO3 Thick Film

2004 ◽  
Vol 828 ◽  
Author(s):  
Jun Tamaki
Keyword(s):  
Thick Film ◽  
Gas Sensors ◽  
High Sensitivity ◽  
Nano Particles ◽  
Gap Size ◽  
Electrode Structure ◽  
Film Sensor ◽  
Sensor Resistance ◽  
Oxide Particles ◽  
20 Nm

ABSTRACTNovel sensor design for high sensitivity gas sensors has been proposed for the detection of dilute NO2 using WO3 film. First, concerning nano-design of oxide particles, the disk-shaped WO3 particles (300 nm in diameter, 20 nm in thickness) were deposited on Au comb-type microelectrode (line width: 5 μm, distance between lines: 5 μm) to be WO3 thick film sensor. This sensor showed the excellent sensing properties to dilute NO2 at optimized thickness. Second, the nano-gap electrode with various gap-sizes (110–1500 nm) was fabricated by means of MEMS techniques in order to investigate the effect of microelectrode. When the gap size was decreased less than 800 nm, the sensitivity to dilute NO2 increased with decreasing gap size. This was understood from the facts that the contribution of interface resistance between particle and electrode to total sensor resistance was increased and that the sensitivity at electrode-grain interface was much larger than that at grain boundary. It was found that the designs of not only nano-particles but also nano-electrode were important for the fabrication of high sensitivity gas sensor.

Modification of Carbon Related Films with Energy Beams

2000 ◽  
Vol 647 ◽  
Author(s):  
Hiroshi Naramoto ◽  
Yonghua Xu ◽  
Kazumasa Narumi ◽  
Xiaodong Zhu ◽  
Jiri Vacik ◽  
...  
Keyword(s):  
Laser Energy ◽  
Ion Beam ◽  
Carbon Films ◽  
Fine Tuning ◽  
Nano Particles ◽  
Raman Spectrometry ◽  
Laser Illumination ◽  
Energy Beam ◽  
Thin Carbon ◽  
Annealing Study

AbstractWe report on typical examples of thin carbon films prepared employing energy beam techniques such as ion beam deposition, ion beam assisted deposition and Laser illumination. In an annealing study of ion beam deposited carbon films, small dots with sub-micron size are isolated through the selective oxidation of sp3-bonded amorphous carbon films, and they were confirmed to be diamond nano-particles by micro-Raman spectrometry. C60 deposition assisted with Ne ion beam results in two kinds of films: 1) The quality of C60 films is improved by the assist of 500eV Ne ion bombardment. 2) The increase of Ne ion Energy results in the decomposition of C60 and the films obtained at 700°C contain possible nano-diamond crystallites at the center of the intense beam spot. The Laser illumination decomposes C60 molecules in general, but the fine-tuning of Laser energy density makes it possible to prepare an array of high luminescent spots.

scholarly journals Spontaneous and coordinated Ca2+ activity of cochlear sensory and non-sensory cells drives the maturation of OHC afferent innervation

2018 ◽  
Author(s):  
Federico Ceriani ◽  
Aenea Hendry ◽  
Jing-Yi Jeng ◽  
Stuart L. Johnson ◽  
Jennifer Olt ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Outer Hair Cells ◽  
Fine Tuning ◽  
Sensory Cells ◽  
Early Postnatal Development ◽  
Acoustic Stimuli ◽  
Ribbon Synapses ◽  
Immature Development ◽  
Afferent Innervation

Outer hair cells (OHCs) are highly specialized sensory cells conferring the fine tuning and high sensitivity of the mammalian cochlea to acoustic stimuli. Here, by genetically manipulating spontaneous Ca2+ signalling in vivo, through a period of early postnatal development, we find that the refinement of OHC afferent innervation is regulated by complementary spontaneous Ca2+ signals originating in OHCs and non-sensory cells. OHCs fire spontaneous Ca2+ spikes during a narrow period of immature development. Simultaneously, waves of Ca2+ activity in the non-sensory greater epithelial ridge act, via ATP-induced activation of P2X receptors, to synchronize OHC firing, resulting in the refinement of their afferent innervation. In the absence of connexin channels Ca2+ waves are impaired, leading to a reduction in the number of ribbon synapses and afferent fibres on OHCs. We propose that the correct maturation of the afferent connectivity in OHCs requires experience-independent Ca2+ signals from sensory and non-sensory cells.

scholarly journals Spin-orbit torque manipulated by fine-tuning of oxygen-induced orbital hybridization

2019 ◽  
Vol 5 (11) ◽  
pp. eaax4278 ◽  
Author(s):  
Yuito Kageyama ◽  
Yuya Tazaki ◽  
Hongyu An ◽  
Takashi Harumoto ◽  
Tenghua Gao ◽  
...  
Keyword(s):  
Nonvolatile Memory ◽  
Scale Effects ◽  
Perpendicular Magnetic Anisotropy ◽  
Atomic Scale ◽  
Fine Tuning ◽  
Spin Orbit ◽  
Spintronic Devices ◽  
Fast Switching ◽  
Orbital Hybridization

Current-induced spin-orbit torques provide an effective way to manipulate magnetization in spintronic devices, promising for fast switching applications in nonvolatile memory and logic units. Recent studies have revealed that the spin-orbit torque is strongly altered by the oxidation of heterostructures with broken inversion symmetry. Although this finding opens a new field of metal-oxide spin-orbitronics, the role of the oxidation in the spin-orbit physics is still unclear. Here, we demonstrate a marked enhancement of the spin-orbit torque induced by a fine-tuning of oxygen-induced modification of orbital hybridization. This is evidenced by a concomitant enhancement of the interface spin-orbit torque, interface spin loss, and interface perpendicular magnetic anisotropy within a narrow range of the oxidation level of metallic heterostructures. This result reveals the crucial role of the atomic-scale effects in the generation of the spin-orbit torques, opening the door to atomic-level engineering of the spin-orbit physics.

Synthesis of Diester Based Magnetic Fluid

2012 ◽  
Vol 217-219 ◽  
pp. 721-724 ◽  
Author(s):  
Hai Rong Cui ◽  
Xue Feng Wang
Keyword(s):  
Magnetic Fluid ◽  
Magnetic Particles ◽  
Research Field ◽  
Nano Particles ◽  
Molar Ratio ◽  
Engineering Research ◽  
Carrier Liquid ◽  
Proper Size ◽  
Environment Temperature ◽  
Magnetic Nano Particles

Diester based magnetic fluid is a novel intelligent material which use diester as carrier liquid and magnetic iron ore as magnetic nano-particles combined together with proper surfactant. Its specially unique characteristic contributes to wide applications in engineering research field such as magnetic fluid based seals, magnetic fluid based dampers and so on. This paper provides a method of diester-based magnetic fluid synthesis and analysis for the properties of prepared diester magnetic fluid as well as effective influencing parameters. The results show that for getting proper size and magnetization of magnetic particles, the proper reacted temperature is around 60~80°C, appropriate molar ratio of reacted solution is 1.75 and concentration of forerunner is about 0.6 mol/L. It is also found that the viscosity of diester-based magnetic fluid is decreased with environment temperature while the viscosity as well as saturation magnetization increases with the increment of density.

New separation method for monoclonal immunoradiometric assays and its application to assays for thyrotropin and human choriogonadotropin.

1984 ◽  
Vol 30 (9) ◽  
pp. 1457-1461 ◽  
Author(s):  
S J Rattle ◽  
D R Purnell ◽  
P I Williams ◽  
K Siddle ◽  
G C Forrest
Keyword(s):  
Monoclonal Antibodies ◽  
Magnetic Particles ◽  
Solid Phase ◽  
Reaction Times ◽  
Fluorescein Isothiocyanate ◽  
High Sensitivity ◽  
Separation Method ◽  
Separation Procedure ◽  
Human Choriogonadotropin ◽  
Capture Antibody

Abstract We describe a novel separation procedure for immunoradiometric assays involving monoclonal antibodies in which both radiolabeled and capture antibodies are used in solution, the capture antibody being labeled with fluorescein isothiocyanate (FITC). Separation is achieved by incubation with anti-FITC antibodies on magnetic particles. This technique enhances reaction kinetics relative to those of assays in which a solid-phase capture antibody is used, thus allowing faster reaction times and more economic use of the monoclonal antibodies. The use of anti-FITC magnetic solid phase produces an assay having a highly specific separation method, minimal nonspecific binding, and high sensitivity. The method is illustrated by application to assays for thyrotropin and human choriogonadotropin.

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