Search results for: Magnetic energy adjustment
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 9856

Search results for: Magnetic energy adjustment

9796 Optimization of Surface Coating on Magnetic Nanoparticles for Biomedical Applications

Authors: Xiao-Li Liu, Ling-Yun Zhao, Xing-Jie Liang, Hai-Ming Fan

Abstract:

Owing to their unique properties, magnetic nanoparticles have been used as diagnostic and therapeutic agents for biomedical applications. Highly monodispersed magnetic nanoparticles with controlled particle size and surface coating have been successfully synthesized as a model system to investigate the effect of surface coating on the T2 relaxivity and specific absorption rate (SAR) under an alternating magnetic field, respectively. Amongst, by using mPEG-g-PEI to solubilize oleic-acid capped 6 nm magnetic nanoparticles, the T2 relaxivity could be significantly increased by up to 4-fold as compared to PEG coated nanoparticles. Moreover, it largely enhances the cell uptake with a T2 relaxivity of 92.6 mM-1s-1 for in vitro cell MRI. As for hyperthermia agent, SAR value increase with the decreased thickness of PEG surface coating. By elaborate optimization of surface coating and particle size, a significant increase of SAR (up to 74%) could be achieved with a minimal variation on the saturation magnetization (<5%). The 19 nm magnetic nanoparticles with 2000 Da PEG exhibited the highest SAR of 930 W•g-1 among the samples, which can be maintained in various simulated physiological conditions. This systematic work provides a general strategy for the optimization of surface coating of magnetic core for high performance MRI contrast agent and hyperthermia agent.

Keywords: magnetic nanoparticles, magnetic hyperthermia, magnetic resonance imaging, surface modification

Procedia PDF Downloads 501
9795 Development of ELF Passive Shielding Application Using Magnetic Aqueous Substrate

Authors: W. N. L. Mahadi, S. N. Syed Zin, W. A. R. Othman, N. A. Mohd Rasyid, N. Jusoh

Abstract:

Public concerns on Extremely Low Frequency (ELF) Electromagnetic Field (EMF) exposure have been elongated since the last few decades. Electrical substations and high tension rooms (HT room) in commercial buildings were among the contributing factors emanating ELF magnetic fields. This paper discussed various shielding methods conventionally used in mitigating the ELF exposure. Nevertheless, the standard methods were found to be impractical and incapable of meeting currents shielding demands. In response to that, remarkable researches were conducted in effort to invent novel methods which is more convenient and efficient such as magnetic aqueous shielding or paint, textiles and papers shielding. A mitigation method using magnetic aqueous substrate in shielding application was proposed in this paper for further investigation. using Manganese Zinc Ferrite (Mn0.4Zn0.6Fe2O4). The magnetic field and flux distribution inside the aqueous magnetic material are evaluated to optimize shielding against ELF-EMF exposure, as to mitigate its exposure.

Keywords: ELF shielding, magnetic aqueous substrate, shielding effectiveness, passive shielding, magnetic material

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9794 The Study of Magnetic and Transport Properties in Normal State Eu1.85+yCe0.15-yCu1-yFeyO4+α-δ

Authors: Risdiana, D. Suhendar, S. Pratiwi, W. A. Somantri, T. Saragi

Abstract:

Superconductor is a promising material for future applications especially for energy saving because of their advantages properties such as zero electrical resistivity when they are cooled down to sufficiently low temperatures. However, the mechanism describing the role of physical properties in superconductor is far from being understood clearly, so that the application of this material for wider benefit in various industries is very limited. Most of superconductors are cuprate compounds, which has CuO2 as a conducting plane in their crystal structures. The study of physical properties through the partially substitution of impurity for Cu in superconducting cuprates has been one of great interests in relation to the mechanism of superconductivity. Different behaviors between the substitution of nonmagnetic impurity and magnetic impurity for Cu are observed. For examples, the superconductivity and Cu-spin fluctuations in the electron-doped system are suppressed through the substitution of magnetic Ni for Cu more markedly than through the substitution of nonmagnetic Zn for Cu, which is contrary to the result in the hole-doped system. Here, we reported the effect of partially substitution of magnetic impurity Fe for Cu to the magnetic and transport properties in electron-doped superconducting cuprates of Eu1.85+yCe0.15-yCu1-yFeyO4+α-δ (ECCFO) with y = 0.01, 0.02, and 0.05, in order to investigate the mechanism of magnetic and transport properties of ECCFO in normal-state. Magnetic properties are investigated by DC magnetic-susceptibility measurements that carried out at low temperatures down to 2 K using a standard SQUID magnetometer in a magnetic field of 5 Oe on field cooling. Transport properties addressed to electron mobility, are extracted from radius of electron localization calculated from temperature dependence of resistivity. For y = 0, temperature dependence of dc magnetic-susceptibility indicated the change of magnetic behavior from paramagnetic to diamagnetic below 15 K. Above 15 K, all samples show paramagnetic behavior with the values of magnetic moment in every volume unit increased with increasing y. Electron mobility decreased with increasing y. Some reasons for these results will be discussed.

Keywords: DC magnetic-susceptibility, electron mobility, Eu1.85+yCe0.15-yCu1-yFeyO4+α-δ, normal state

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9793 Electro Magnetic Tractor (E. M. Tractor)

Authors: Sijo Varghese

Abstract:

A space craft (E. M. Tractor) which is intended to deflect or tug the asteroids which possesses threat towards the planets is the whole idea behind this paper. In this case "Electro Magnetic Induction" is used where it is known that when two separate circuits are connected to the electro magnet and on application of electric current through the one circuit in to the coil induces magnetic fields which repels the other circuit.( Faraday's law of Electromagnetic Induction). Basically a Spacecraft is used to attach a large sheet of aluminum on to the surface of the asteroid, the Spacecraft acts as an electro magnet and the induced magnetic field would eventually repel the aluminum intern repelling the asteroid. This method would take less time as compared to use of gravity( which requires a larger spacecraft and process will take a long time).

Keywords: asteroids, electro magnetic induction, gravity, electro magnetic tractor

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9792 New Refrigerant La₀.₇Ca₀.₁₅Sr₀.₁₅Mn₁₋ₓGaₓO₃ for Application in Magnetic Refrigeration

Authors: Essebti Dhahri

Abstract:

We present a new refrigerant La₀.₇Ca₀.₁₅Sr₀.₁₅Mn₁₋ₓGaₓO₃ (x = 0.0-0.1) manganites. These compounds were prepared by the sol-gel method. The refinement of the X-ray diffraction reveals that all samples crystallize in a rhombohedral structure (space group R3 ̅c). Detailed measurements of the magnetization as a function of temperature and magnetic applied field M (µ₀H, T) were carried out. From the M(µ₀H, T) curves, we have calculated the magnetic entropy change (ΔSM) according to the Maxwell relation. The temperature dependence of the magnetization M(T) reveals a decrease of M when increasing the x content. The magnetic entropy change (ΔSM) reaches a maximum value near room temperature. It was also found that this compound exhibits a large magnetocaloric effect MCE which increases when decreasing Ga concentration. So, the studied compounds could be considered potential materials for magnetic refrigeration application.

Keywords: magnetic measurements, Rietveld refinement, magnetic refrigeration, magnetocaloric effect

Procedia PDF Downloads 83
9791 Double Magnetic Phase Transition in the Intermetallic Compound Gd₂AgSi₃

Authors: Redrisse Djoumessi Fobasso, Baidyanath Sahu, Andre M. Strydom

Abstract:

The R₂TX₃ (R = rare-earth, T = transition, and X = s and p block element) series of compounds are interesting owing to their fascinating structural and magnetic properties. In this present work, we have studied the magnetic and physical properties of the new Gd₂AgSi₃ polycrystalline compound. The sample was synthesized by the arc-melting method and confirmed to crystallize in the tetragonal α-ThSi₂-type crystal structure with space group I4/amd. Dc– and ac–magnetic susceptibility, specific heat, electrical resistivity, and magnetoresistance measurements were performed on the new compound. The structure provides a unique position in the unit cell for the magnetic trivalent Gd ion. Two magnetic phase transitions were consistently found in dc- and ac-magnetic susceptibility, heat capacity, and electrical resistivity at temperatures Tₙ₁ = 11 K and Tₙ₂ = 20 K, which is an indication of the complex magnetic behavior in this compound. The compound is found to be metamagnetic over a range of temperatures below and above Tₙ₁. From field-dependent electrical resistivity, it is confirmed that the compound shows unusual negative magnetoresistance in the antiferromagnetically ordered region. These results contribute to a better understanding of this class of materials.

Keywords: complex magnetic behavior, metamagnetic, negative magnetoresistance, two magnetic phase transitions

Procedia PDF Downloads 116
9790 Magnetic Field Generation in Inhomogeneous Plasma via Ponderomotive Force

Authors: Fatemeh Shahi, Mehdi Sharifian, Laia Shahrassai, Elham Eskandari A.

Abstract:

A new mechanism is reported here for magnetic field generation in laser-plasma interaction by means of nonlinear ponderomotive force. The plasma considered here is unmagnetized inhomogeneous plasma with an exponentially decreasing profile. A damped periodic magnetic field with a relatively lower frequency is obtained using the ponderomotive force exerted on plasma electrons. Finally, with an electric field and by using Faraday’s law, the magnetic field profile in the plasma has been obtained. Because of the negative exponential density profile, the generated magnetic field is relatively slowly oscillating and damped through the plasma.

Keywords: magnetic field generation, laser-plasma interaction, ponderomotive force, inhomogeneous plasma

Procedia PDF Downloads 279
9789 Coping Techniques, Repertoire, and Flexibility in Parental Adjustment to Pediatric Cancer

Authors: Michael Dolgin, Oz Hamtzani, Talma Kushnir

Abstract:

A literature review has shown that while parents of children with cancer experience increased levels of psychological distress associated with their child's medical condition, considerable variability in parental adjustment is evident. Of the factors that may account for this variability, little attention has been devoted to the simultaneous interaction of three coping constructs and their role in parental adjustment: (1) Coping techniques employed, (2) Repertoire of coping techniques, and (3) Flexibility in applying coping techniques. While these constructs have been studied individually in relation to adjustment in general, studies to date have not included them together within a single conceptual model and research design and evaluated them in a clinical population. The objective of the current study was to determine how these three coping technique constructs interact to impact parental adjustment to pediatric cancer. A cross-sectional sample of 145 parents of children in active cancer treatment completed standardized measures of coping techniques, repertoire, flexibility, and parental distress. A hierarchical multiple regression analysis demonstrated that 37% of the variance in parental distress was predicted by the use of avoidance-focused coping techniques [F(1,118)=69.843, p<.001], with an additional 3% predicted by coping repertoire [F(2,117)=7.63, p=.00] for a total of 40% variance explained. Coping flexibility was found to mediate the relationship between coping repertoire and parental distress. These findings suggest that coping techniques employed by parents (problem/emotion-focused vs. avoidance-focused), as well as coping repertoire, significantly impact parental adjustment. Flexibility in applying coping techniques within one’s coping repertoire further contributes to parental adjustment. Implications for further study and clinical intervention will be presented.

Keywords: coping techniques, repertoire, flexibility, adjustment

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9788 Magnetic Susceptibility Measurements of Urban Areas in Denizli City and Showing the Distributions of Heavy Metal Pollution

Authors: Ali Aydin

Abstract:

Three hundred and fifty soil samples were collected around the urban and residential area, for the purpose of a magnetic susceptibility study on pollution in Denizli City, Turkiye. Measurements of volume-specific magnetic susceptibility (к) and mass-specific magnetic susceptibility (χ) show a significant variation range from place to place collected soil samples. In this study, we did a primary magnetic study near the high heavy traffic pollution in a part of Denizli city, Turkiye which was said the most polluted city in Aegean Region of Turkey. The magnetic susceptibility measurements increased from the garden area to residential area and reached the high levels near the industrial areas of the city. Magnetic particle concentration and grain size sourced exhaust gasses, and other pollution sources increase with the increasing distance from a residential area, indicating the high traffic road area.

Keywords: magnetic susceptibility, pollution, magnetic particle, Denizli

Procedia PDF Downloads 288
9787 Functionalized Magnetic Iron Oxide Nanoparticles for Extraction of Protein and Metal Nanoparticles from Complex Fluids

Authors: Meenakshi Verma, Mandeep Singh Bakshi, Kultar Singh

Abstract:

Magnetic nanoparticles have received incredible importance in view of their diverse applications, which arise primarily due to their response to the external magnetic field. The magnetic behaviour of magnetic nanoparticles (NPs) helps them in numerous different ways. The most important amongst them is the ease with which they can be purified and also can be separated from the media in which they are present merely by applying an external magnetic field. This exceptional ease of separation of the magnetic NPs from an aqueous media enables them to use for extracting/removing metal pollutants from complex aqueous medium. Functionalized magnetic NPs can be subjected for the metallic impurities extraction if are favourably adsorbed on the NPs surfaces. We have successfully used the magnetic NPs as vehicles for gold and silver NPs removal from the complex fluids. The NPs loaded with gold and silver NPs pollutant fractions has been easily removed from the aqueous media by using external magnetic field. Similarly, we have used the magnetic NPs for extraction of protein from complex media and then constantly washed with pure water to eliminate the unwanted surface adsorbed components for quantitative estimation. The purified and protein loaded magnetic NPs are best analyzed with SDS Page to not only for characterization but also for separating the protein fractions. A collective review of the results indicates that we have synthesized surfactant coated iron oxide NPs and then functionalized these with selected materials. These surface active magnetic NPs work very well for the extraction of metallic NPs from the aqueous bulk and make the whole process environmentally sustainable. Also, magnetic NPs-Au/Ag/Pd hybrids have excellent protein extracting properties. They are much easier to use in order to extract the magnetic impurities as well as protein fractions under the effect of external magnetic field without any complex conventional purification methods.

Keywords: magnetic nanoparticles, protein, functionalized, extraction

Procedia PDF Downloads 93
9786 Energy Consumption Forecast Procedure for an Industrial Facility

Authors: Tatyana Aleksandrovna Barbasova, Lev Sergeevich Kazarinov, Olga Valerevna Kolesnikova, Aleksandra Aleksandrovna Filimonova

Abstract:

We regard forecasting of energy consumption by private production areas of a large industrial facility as well as by the facility itself. As for production areas the forecast is made based on empirical dependencies of the specific energy consumption and the production output. As for the facility itself implementation of the task to minimize the energy consumption forecasting error is based on adjustment of the facility’s actual energy consumption values evaluated with the metering device and the total design energy consumption of separate production areas of the facility. The suggested procedure of optimal energy consumption was tested based on the actual data of core product output and energy consumption by a group of workshops and power plants of the large iron and steel facility. Test results show that implementation of this procedure gives the mean accuracy of energy consumption forecasting for winter 2014 of 0.11% for the group of workshops and 0.137% for the power plants.

Keywords: energy consumption, energy consumption forecasting error, energy efficiency, forecasting accuracy, forecasting

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9785 A Multi-Objective Optimization Tool for Dual-Mode Operating Active Magnetic Regenerator Model

Authors: Anna Ouskova Leonteva, Michel Risser, Anne Jeannin-Girardon, Pierre Parrend, Pierre Collet

Abstract:

This paper proposes an efficient optimization tool for an active magnetic regenerator (AMR) model, operating in two modes: magnetic refrigeration system (MRS) and thermo-magnetic generator (TMG). The aim of this optimizer is to improve the design of the AMR by applying a multi-physics multi-scales numerical model as a core of evaluation functions to achieve industrial requirements for refrigeration and energy conservation systems. Based on the multi-objective non-dominated sorting genetic algorithm 3 (NSGA3), it maximizes four different objectives: efficiency and power density for MRS and TMG. The main contribution of this work is in the simultaneously application of a CPU-parallel NSGA3 version to the AMR model in both modes for studying impact of control and design parameters on the performance. The parametric study of the optimization results are presented. The main conclusion is that the common (for TMG and MRS modes) optimal parameters can be found by the proposed tool.

Keywords: ecological refrigeration systems, active magnetic regenerator, thermo-magnetic generator, multi-objective evolutionary optimization, industrial optimization problem, real-world application

Procedia PDF Downloads 107
9784 A Case Study of Decision Making and Adjustment Behaviour of Visually Challenged Adolescents

Authors: Bincy Mathew, B. William Dharma Raja

Abstract:

Successful decision making in a social setting depends on the ability to understand the intentions, emotions and beliefs of others. Children live and grow in the social world. Individuals think to satisfy their curiosity and mush of their social thought is practical, to attain their goal. Children’s thought about their social world influences how they behave towards it. The main purpose of this paper is to review the influence of decision making on adjustment behaviour of visually challenged adolescents. The sample was purposively selected to study the cases of two of the visually challenged adolescents from a Special School, in Tirunelveli, Tamil Nadu, India. The authors appraised the observed behaviour of adjustment in these children. It may be concluded that the social cognitive ability of decision making is at least, to certain extent, influences adjustment behaviour of visually challenged adolescents. Adjustment behaviour attempts to maintain a child’s level of physiological and psychological equilibrium and it is directed towards tension reduction. It involves a state of harmonious relationship existing between the individual and one’s environment so that adjustment is a matter of interaction between the capacities of the individual and the demands of the environment. The study also found that music induces a receptive mood that generally enhances cognitive processing and every decision that the child makes has its brunt on the behaviour. It is solely based on the case study carried out by the authors.

Keywords: social cognition, decision making, adjustment behaviour, adolescents

Procedia PDF Downloads 250
9783 Estimation of Particle Size Distribution Using Magnetization Data

Authors: Navneet Kaur, S. D. Tiwari

Abstract:

Magnetic nanoparticles possess fascinating properties which make their behavior unique in comparison to corresponding bulk materials. Superparamagnetism is one such interesting phenomenon exhibited only by small particles of magnetic materials. In this state, the thermal energy of particles become more than their magnetic anisotropy energy, and so particle magnetic moment vectors fluctuate between states of minimum energy. This situation is similar to paramagnetism of non-interacting ions and termed as superparamagnetism. The magnetization of such systems has been described by Langevin function. But, the estimated fit parameters, in this case, are found to be unphysical. It is due to non-consideration of particle size distribution. In this work, analysis of magnetization data on NiO nanoparticles is presented considering the effect of particle size distribution. Nanoparticles of NiO of two different sizes are prepared by heating freshly synthesized Ni(OH)₂ at different temperatures. Room temperature X-ray diffraction patterns confirm the formation of single phase of NiO. The diffraction lines are seen to be quite broad indicating the nanocrystalline nature of the samples. The average crystallite size are estimated to be about 6 and 8 nm. The samples are also characterized by transmission electron microscope. Magnetization of both sample is measured as function of temperature and applied magnetic field. Zero field cooled and field cooled magnetization are measured as a function of temperature to determine the bifurcation temperature. The magnetization is also measured at several temperatures in superparamagnetic region. The data are fitted to an appropriate expression considering a distribution in particle size following a least square fit procedure. The computer codes are written in PYTHON. The presented analysis is found to be very useful for estimating the particle size distribution present in the samples. The estimated distributions are compared with those determined from transmission electron micrographs.

Keywords: anisotropy, magnetization, nanoparticles, superparamagnetism

Procedia PDF Downloads 136
9782 Supercomputer Simulation of Magnetic Multilayers Films

Authors: Vitalii Yu. Kapitan, Aleksandr V. Perzhu, Konstantin V. Nefedev

Abstract:

The necessity of studying magnetic multilayer structures is explained by the prospects of their practical application as a technological base for creating new storages medium. Magnetic multilayer films have many unique features that contribute to increasing the density of information recording and the speed of storage devices. Multilayer structures are structures of alternating magnetic and nonmagnetic layers. In frame of the classical Heisenberg model, lattice spin systems with direct short- and long-range exchange interactions were investigated by Monte Carlo methods. The thermodynamic characteristics of multilayer structures, such as the temperature behavior of magnetization, energy, and heat capacity, were investigated. The processes of magnetization reversal of multilayer structures in external magnetic fields were investigated. The developed software is based on the new, promising programming language Rust. Rust is a new experimental programming language developed by Mozilla. The language is positioned as an alternative to C and C++. For the Monte Carlo simulation, the Metropolis algorithm and its parallel implementation using MPI and the Wang-Landau algorithm were used. We are planning to study of magnetic multilayer films with asymmetric Dzyaloshinskii–Moriya (DM) interaction, interfacing effects and skyrmions textures. This work was supported by the state task of the Ministry of Education and Science of the Russia # 3.7383.2017/8.9

Keywords: The Monte Carlo methods, Heisenberg model, multilayer structures, magnetic skyrmion

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9781 Effects of Magnetic Field Strength on Fluid Flow Behavior in a Constricted Channel

Authors: Ashkan Javadzadegan, Aitak Javadzadegan, Babak Fakhim

Abstract:

One of possible ways to retard movement of fluid is through applying an external magnetic field. In this regard, this study is focused on the effect of a uniform transverse magnetic field on fluid flow behavior inside a channel with a local symmetric constriction. Also, Ellis Non-Newtonian model is implemented to address the effects of shear-dependent viscosity. According to the results, the flow separation downstream of the constriction can be controlled by applying an external magnetic field and/or manipulating the shear-thinning degree of fluid. It is also demonstrated that pressure drop increases by an increase in the strength of the magnetic field.

Keywords: magnetic field, non-Newtonian, separation, shear thinning

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9780 Quantom Magnetic Effects of P-B Fusion in Plasma Focus Devices

Authors: M. Habibi

Abstract:

The feasibility of proton-boron fusion in plasmoids caused by magneto hydrodynamics instabilities in plasma focus devices is studied analytically. In plasmoids, fusion power for 76 keV < Ti < 1500 keV exceeds bremsstrahlung loss (W/Pb=5.39). In such situation gain factor and the ratio of Te to Ti for a typical 150 kJ plasma focus device will be 7.8 and 4.8 respectively. Also with considering the ion viscous heating effect, W/Pb and Ti/Te will be 2.7 and 6 respectively. Strong magnetic field will reduces ion-electron collision rate due to quantization of electron orbits. While approximately there is no change in electron-ion collision rate, the effect of quantum magnetic field makes ions much hotter than electrons which enhance the fraction of fusion power to bremsstrahlung loss. Therefore self-sustained p-11B fusion reactions would be possible and it could be said that p-11B fuelled plasma focus device is a clean and efficient source of energy.

Keywords: plasmoids, p11B fuel, ion viscous heating, quantum magnetic field, plasma focus device

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9779 A Study on the Magnetic and Mechanical Properties of Nd-Fe-B Sintered Magnets According to Sintering Temperature

Authors: J. H. Kim, S. Y. Park, K. M. Lim, S. K. Hyun

Abstract:

The effect of sintering temperature on the magnetic and mechanical properties of Nd-Fe-B sintered magnets has been investigated in this study. The sintering temperature changed from 950°C to 1120°C. While remanence and hardness of the magnets increased with increasing sintering temperature, the coercivity first increased, and then decreased. The optimum magnetic and mechanical properties of the magnets were obtained at the sintering temperature of 1050°C. In order to clarify the reason for the variation on magnetic and mechanical properties of the magnets, we systematically analyzed the microstructure.

Keywords: magnetic and mechanical property, microstructure, permanent magnets, sintered Nd-Fe-B magnet

Procedia PDF Downloads 326
9778 Gamma Irradiation Effects on the Magnetic Properties of Hard Ferrites

Authors: F. Abbas Pour Khotbehsara, B. Salehpour, A. Kianvash

Abstract:

Many industrial materials like magnets need to be tested for the radiation environment expected at linear colliders (LC) where the accelerator and detectors will be subjected to large influences of beta, neutron and gamma’s over their life Gamma irradiation of the permanent sample magnets using a 60Co source was investigated up to an absorbed dose of 700Mrad shows a negligible effect on some magnetic properties of Nd-Fe-B. In this work, it has been tried to investigate the change of some important properties of Barium hexa ferrite. Results showed little decreases of magnetic properties at doses rang of 0.5 to 2.5 Mrad. But at the gamma irradiation dose up to 10 Mrad it is showed a few increase of properties. Also study of gamma irradiation of Nd-Fe-B showed considerably increase of magnetic properties.

Keywords: gamma ray irradiation, hard ferrite, magnetic coefficient, magnetic material, radiation dose

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9777 Influence of Magnetic Bio-Stimulation Effects on Pre-Sown Hybrid Sunflower Seeds Germination, Growth, and on the Percentage of Antioxidant Activities

Authors: Nighat Zia-ud-Den, Shazia Anwer Bukhari

Abstract:

In the present study, sunflower seeds were exposed to magnetic bio-stimulation at different milli Tesla, and their effects were studied. The present study addressed to establish the effectiveness of magnetic bio-stimulation on seed germination, growth, and other dynamics of crop growth. The changes in physiological characters, i.e. the growth parameters of seedlings (biomass, root and shoot length, fresh and dry weight of root shoot leaf and fruit, leaf area, the height of plants, number of leaves, and number of fruits per plant) and antioxidant activities were measured. The parameters related to germination and growth were measured under controlled conditions while they changed significantly compared with that of the control. These changes suggested that magnetic seed stimulator enhanced the inner energy of seeds, which contributed to the acceleration of the growth and development of seedlings. Moreover, pretreatment with a magnetic field was found to be a positive impact on sunflower seeds germination, growth, and other biochemical parameters.

Keywords: sunflower seeds, physical priming method, biochemical parameters, antioxidant activities

Procedia PDF Downloads 152
9776 Adaptive Threshold Adjustment of Clear Channel Assessment in LAA Down Link

Authors: Yu Li, Dongyao Wang, Xiaobao Sun, Wei Ni

Abstract:

In long-term evolution (LTE), the carriers around 5GHz are planned to be utilized without licenses to further enlarge system capacity. This feature is termed licensed assisted access (LAA). The channel sensing (clean channel assessment, CCA) is required before any transmission on these unlicensed carriers, in order to make sure the harmonious co-existence of LAA with other radio access technology in the unlicensed band. Obviously, the CCA threshold is very critical, which decides whether the transmission right following CCA is delivered in time and without collisions. An improper CCA threshold may cause buffer overflow of some eNodeBs if the eNodeBs are heavily loaded with the traffic. Thus, to solve these problems, we propose an adaptive threshold adjustment method for CCA in the LAA downlink. Both the load and transmission opportunities are concerned. The trend of the LAA throughput as the threshold varies is obtained, which guides the threshold adjustment. The co-existing between LAA and Wi-Fi is particularly tested. The results from system-level simulation confirm the merits of our design, especially in heavy traffic cases.

Keywords: LTE, LAA, CCA, threshold adjustment

Procedia PDF Downloads 134
9775 Harvesting Energy from Lightning Strikes

Authors: Vaishakh Medikeri

Abstract:

Lightning, the marvelous, spectacular and the awesome truth of nature is one of the greatest energy sources left unharnessed since ages. A single lightning bolt of lightning contains energy of about 15 billion joules. This huge amount of energy cannot be harnessed completely but partially. This paper proposes to harness the energy from lightning strikes. Throughout the globe the frequency of lightning is 40-50 flashes per second, totally 1.4 billion flashes per year; all of these flashes carrying an average energy of about 15 billion joules each. When a lightning bolt strikes the ground, tremendous amounts of energy is transferred to earth which propagates in the form of concentric circular energy waves. These waves have a frequency of about 7.83Hz. Harvesting the lightning bolt directly seems impossible, but harvesting the energy waves produced by the lightning is pretty easier. This can be done using a tricoil energy harnesser which is a new device which I have invented. We know that lightning bolt seeks the path which has minimum resistance down to the earth. For this we can make a lightning rod about 100 meters high. Now the lightning rod is attached to the tricoil energy harnesser. The tricoil energy harnesser contains three coils whose centers are collinear and all the coils are parallel to the ground. The first coil has one of its ends connected to the lightning rod and the other end grounded. There is a secondary coil wound on the first coil with one of its end grounded and the other end pointing to the ground and left unconnected and placed a little bit above the ground so that this end of the coil produces more intense currents, hence producing intense energy waves. The first coil produces very high magnetic fields and induces them in the second and third coils. Along with the magnetic fields induced by the first coil, the energy waves which are currents also flow through the second and the third coils. The second and the third coils are connected to a generator which in turn is connected to a capacitor which stores the electrical energy. The first coil is placed in the middle of the second and the third coil. The stored energy can be used for transmission of electricity. This new technique of harnessing the lightning strikes would be most efficient in places with more probability of the lightning strikes. Since we are using a lightning rod sufficiently long, the probability of cloud to ground strikes is increased. If the proposed apparatus is implemented, it would be a great source of pure and clean energy.

Keywords: generator, lightning rod, tricoil energy harnesser, harvesting energy

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9774 Cr Induced Magnetization in Zinc-Blende ZnO-Based Diluted Magnetic Semiconductors

Authors: Bakhtiar Ul Haq, R. Ahmed, A. Shaari, Mazmira Binti Mohamed, Nisar Ali

Abstract:

The capability of exploiting the electronic charge and spin properties simultaneously in a single material has made diluted magnetic semiconductors (DMS) remarkable in the field of spintronics. We report the designing of DMS based on zinc-blend ZnO doped with Cr impurity. The full potential linearized augmented plane wave plus local orbital FP-L(APW+lo) method in density functional theory (DFT) has been adapted to carry out these investigations. For treatment of exchange and correlation energy, generalized gradient approximations have been used. Introducing Cr atoms in the matrix of ZnO has induced strong magnetic moment with ferromagnetic ordering at stable ground state. Cr:ZnO was found to favor the short range magnetic interaction that reflect the tendency of Cr clustering. The electronic structure of ZnO is strongly influenced in the presence of Cr impurity atoms where impurity bands appear in the band gap.

Keywords: ZnO, density functional theory, diluted agnetic semiconductors, ferromagnetic materials, FP-L(APW+lo)

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9773 Mathematical Modelling of Blood Flow with Magnetic Nanoparticles as Carrier for Targeted Drug Delivery in a Stenosed Artery

Authors: Sreeparna Majee, G. C. Shit

Abstract:

A study on targeted drug delivery is carried out in an unsteady flow of blood infused with magnetic NPs (nanoparticles) with an aim to understand the flow pattern and nanoparticle aggregation in a diseased arterial segment having stenosis. The magnetic NPs are supervised by the magnetic field which is significant for therapeutic treatment of arterial diseases, tumor and cancer cells and removing blood clots. Coupled thermal energy have also been analyzed by considering dissipation of energy because of the application of the magnetic field and the viscosity of blood. Simulation technique used to solve the mathematical model is vorticity-stream function formulations in the diseased artery. An elevation in SLP (Specific loss power) is noted in the aortic bloodstream when the agglomeration of nanoparticles is higher. This phenomenon has potential application in the treatment of hyperthermia. The study focuses on the lowering of WSS (Wall Shear Stress) with increasing particle concentration at the downstream of the stenosis which depicts the vigorous flow circulation zone. These low shear stress regions prolong the residing time of the nanoparticles carrying drugs which soaks up the LDL (Low Density Lipoprotein) deposition. Moreover, an increase in NP concentration enhances the Nusselt number which marks the increase of heat transfer from the arterial wall to the surrounding tissues to destroy tumor and cancer cells without affecting the healthy cells. The results have a significant influence in the study of medicine, to treat arterial diseases such as atherosclerosis without the need for surgery which can minimize the expenditures on cardiovascular treatments.

Keywords: magnetic nanoparticles, blood flow, atherosclerosis, hyperthermia

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9772 Increasing Toughness of Oriented Polyvinyl Alcohol (PVA)/Fe3O4 Nanocomposite

Authors: Mozhgan Chaichi, Farhad Sharif, Saeede Mazinani

Abstract:

Polymer nanocomposites are a new class of materials for fabricating future multifunctional and lightweight structures. To obtain good mechanical, thermal and electrical properties, it is essential to achieve uniform dispersion of nanoparticles in polymer matrix. Alignment of nanoparticles in matrix can enhance mechanical, thermal, electrical and barrier properties of nanocomposites in oriented direction. Fe3O4 nanoparticles have generated huge activity in many areas of science and engineering due to its magnetic properties. Magnetic nanoparticles have been investigated for a wide range of applications in sensors, magnetic energy storage, environmental remediation, heterogeneous catalysts and drug delivery. The magnetic response from the Fe3O4 nanoparticles can facilitate with the alignment of nanofillers in a polymer matrix under magnetic field, aiming at fabricating composites with directional properties and functions. Here we report oriented nanocomposites based on Fe3O4 nanoparticles and poly (vinyl alcohol) (PVA), which prepared via a facile aqueous solution by applying a low external magnetic field (750 G). A significant enhancement of mechanical properties, and especially toughness of nanofilms, of oriented PVA/ Fe3O4 nanocomposites is obtained at low nanoparticles loading. Orientation of nanoparticles can align polymer chains and enhance mechanical properties. For example, orientation of 0.1 wt. % Fe3O4 nanoparticles increase 31% toughness and 23% modulus of oriented nanocomposite in compare of pure films, which indicate good dispersion of nanoparticles and efficient load transfer between nanoparticles and matrix.

Keywords: magnetic nanoparticles, nanocomposites, toughness, orientation

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9771 Functionalized SPIO Conjugated with Doxorubicin for Tumor Diagnosis and Chemotherapy Enhanced by Applying Magnetic Fields

Authors: Po-Chin Liang, Yung-Chu Chen, Chi-Feng Chiang, Yun-Ping Lin, Wen-Yuan Hsieh, Win-Li Lin

Abstract:

The aim of this study was to develop super paramagnetic iron oxide (SPIO) nano-particles comprised of a magnetic Fe3O4 core and a shell of aqueous stable self-doped polyethylene glycol (PEG) with a high loading of doxorubicin (SPIO-PEG-D) for tumor theranostics. The in-vivo MRI study showed that there was a stronger T2-weighted signal enhancement for the group under a magnetic field, and hence it indicated that this group had a better accumulation of SPIO-PEG than the group without a magnetic field. In the anticancer evaluation of SPIO-PEG-D, the group with a magnetic field displayed a significantly smaller tumor size than the group without. The overall results show that SPIO-PEG-D nanoparticles have the potential for the application of MRI/monitoring chemotherapy and the therapy can be locally enhanced by applying an external magnetic field.

Keywords: super paramagnetic iron oxide nano particles, doxorubicin, chemotherapy, MRI, magnetic fields

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9770 Relation Between Marital Adjustment and Parenting: The Moderating Effect of Children´s Temperament

Authors: Ester Ato, Maria Angeles Fernández-Vilar, Maria Dolores Galián

Abstract:

The aim of this work was to analyze the relation between children´s effortful control, marital adjustment and parenting practices in a sample of 345 Spanish children aged between 6 and 8 years. Traditionally, the literature confirms that a higher level of marital conflict has been associated with less effective and less positive parenting, but there are few studies that include the effect that children´s effortful control exert to this relation. To measure marital adjustment, parenting practices and children’s temperament, parents were given the Marital Adjustment Test (MAT), the Spanish version of the PCRI (Parent-Child Relationship Inventory), and the TMCQ (Temperament in Middle Childhood Questionnaire). The results confirmed that higher marital satisfaction predicted more positive parenting practices, whereas lower marital adjustment scores predicted less parenting support and control. Using a statistical modeling approach, we tested a moderation model that revealed the moderating role of effortful control in the relation between marital adjustment and parenting. Concretely, higher marital satisfaction predicts higher parenting communication and involvement, but only in children with low levels of effortful control. Therefore, a difficult temperament interferes in a less negative way in the family system when parents are satisfied and united. And a better self-regulated child predicts more effective parenting practice regardless of the parents´ marital satisfaction. The clinical implications of the present findings should be considered. Specifically, difficult children must be detected and evaluated in community settings, such as school or community programs, in order to take into account the marital adjustment and parenting practices of their parents, and to be able to design adequate family interventions and prevent future pathologizing patterns.

Keywords: effortful control, marital adjustment, parenting, moderation

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9769 Magnetic Field Analysis of External Rotor Permanent-Magnet Synchronous Motors with Non Magnetic Rotor Core

Authors: Mabrak Samir

Abstract:

The motor performance created by permanent magnetic in a slotless air-gap of a surface mounted permanent-magnet synchronous motor with non magnetic rotor and either sinusoidal or mixed (quasi-Halbatch) magnetization is presented in this paper using polar coordinates. The analysis works for both internal and external rotor motor topologies, The effect of stator slots is introduced by modulating the magnetic field distribution in the slotless stator by the complex relative air-gap permeance, calculated from the conformal transformation of the slot geometry. We compare predicted results of flux density distribution and cogging torque with those obtained by finite-element analysis.

Keywords: air-cored, cogging torque, finite element magnetic field, permanent-magnet

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9768 Investigation of the Litho-Structure of Ilesa Using High Resolution Aeromagnetic Data

Authors: Oladejo Olagoke Peter, Adagunodo T. A., Ogunkoya C. O.

Abstract:

The research investigated the arrangement of some geological features under Ilesa employing aeromagnetic data. The obtained data was subjected to various data filtering and processing techniques, which are Total Horizontal Derivative (THD), Depth Continuation and Analytical Signal Amplitude using Geosoft Oasis Montaj 6.4.2 software. The Reduced to the Equator –Total Magnetic Intensity (TRE-TMI) outcomes reveal significant magnetic anomalies, with high magnitude (55.1 to 155 nT) predominantly at the Northwest half of the area. Intermediate magnetic susceptibility, ranging between 6.0 to 55.1 nT, dominates the eastern part, separated by depressions and uplifts. The southern part of the area exhibits a magnetic field of low intensity, ranging from -76.6 to 6.0 nT. The lineaments exhibit varying lengths ranging from 2.5 and 16.0 km. Analyzing the Rose Diagram and the analytical signal amplitude indicates structural styles mainly of E-W and NE-SW orientations, particularly evident in the western, SW and NE regions with an amplitude of 0.0318nT/m. The identified faults in the area demonstrate orientations of NNW-SSE, NNE-SSW and WNW-ESE, situated at depths ranging from 500 to 750 m. Considering the divergence magnetic susceptibility, structural style or orientation of the lineaments, identified fault and their depth, these lithological features could serve as a valuable foundation for assessing ground motion, particularly in the presence of sufficient seismic energy.

Keywords: lineament, aeromagnetic, anomaly, fault, magnetic

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9767 Experimental Study on Capturing of Magnetic Nanoparticles Transported in an Implant Assisted Cylindrical Tube under Magnetic Field

Authors: Anurag Gaur Nidhi

Abstract:

Targeted drug delivery is a method of delivering medication to a patient in a manner that increases the concentration of the medication in some parts of the body relative to others. Targeted drug delivery seeks to concentrate the medication in the tissues of interest while reducing the relative concentration of the medication in the remaining tissues. This improves efficacy of the while reducing side effects. In the present work, we investigate the effect of magnetic field, flow rate and particle concentration on the capturing of magnetic particles transported in a stent implanted fluidic channel. Iron oxide magnetic nanoparticles (Fe3O4) nanoparticles were synthesized via co-precipitation method. The synthesized Fe3O4 nanoparticles were added in the de-ionized (DI) water to prepare the Fe3O4 magnetic particle suspended fluid. This fluid is transported in a cylindrical tube of diameter 8 mm with help of a peristaltic pump at different flow rate (25-40 ml/min). A ferromagnetic coil of SS 430 has been implanted inside the cylindrical tube to enhance the capturing of magnetic nanoparticles under magnetic field. The capturing of magnetic nanoparticles was observed at different magnetic magnetic field, flow rate and particle concentration. It is observed that capture efficiency increases from 47-67 % at magnetic field 2-5kG, respectively at particle concentration 0.6 mg/ml and at flow rate 30 ml/min. However, the capture efficiency decreases from 65 to 44 % by increasing the flow rate from 25 to 40 ml/min, respectively. Furthermore, it is observed that capture efficiency increases from 51 to 67 % by increasing the particle concentration from 0.3 to 0.6 mg/ml, respectively.

Keywords: capture efficiency, implant assisted-Magnetic drug targeting (IA-MDT), magnetic nanoparticles, In-vitro study

Procedia PDF Downloads 297