No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
A simplified mathematical study of thermochemical preparation of particle oxide under counterflow configuration for use in biomedical applications
Abstract
This study mathematically presents a counterflow non-premixed thermochemical technique for preparing a particle oxide used for cancer diagnosis and treatment. For this purpose, preheating, reaction, melting, and oxidation processes were simulated considering an asymptotic concept. Mass and energy conservation equations in dimensional and non-dimensional forms were solved using MATLAB®. To preserve the continuity in the system and calculate the locations of melting and flame fronts, promising jump conditions were derived. In this research, variations in flame temperature, flame front location and mass fractions of the particle, particle oxide and oxidizer, with position, Lewis number and initial temperature of the particles were investigated. The simulation results were compared with those obtained from an earlier experimental study under the same conditions. Regarding the comparison, an appropriate compatibility was observed between the results. Based on the simulation results, flame temperature was found to be about 1310 K. Positions of flame and melting fronts were found to be − 1.8 mm and − 1.78 mm, respectively.
... The flow behavior in MDT was studied by several groups [496][497][498][499][500], as well as their ability to penetrate different types of tissues, including eye tissue [501]. The modeling of flow behavior is even more important when the targeted disease is localized at the arterial segment (atherosclerosis), where control of NP aggregation is vital and is addressed by numerical solving of vorticity stream-function formulation [497]. ...
... The modeling of flow behavior is even more important when the targeted disease is localized at the arterial segment (atherosclerosis), where control of NP aggregation is vital and is addressed by numerical solving of vorticity stream-function formulation [497]. Other research groups studied the potential removal of MNP-tagged cytokine during cardiopulmonary bypass, by employing simulation methods based on Navier-Stokes equations [498], or the feasibility study of introducing multicore MNPs of ~50 nm through the eye tissue using a magnetic field gradient of 20 T m −1 [501]. Many of the research groups concluded that the best results in MDT can be obtained only when affected tissues are close to the body surface, hence the depth factor of the tumor seems to be prevalent. ...
Magnetic nanoparticles (MNPs) have evolved tremendously during recent years, in part due to the rapid expansion of nanotechnology and to their active magnetic core with a high surface-to-volume ratio, while their surface functionalization opened the door to a plethora of drug, gene and bioactive molecule immobilization. Taming the high reactivity of the magnetic core was achieved by various functionalization techniques, producing MNPs tailored for the diagnosis and treatment of cardiovascular or neurological disease, tumors and cancer. Superparamagnetic iron oxide nanoparticles (SPIONs) are established at the core of drug-delivery systems and could act as efficient agents for MFH (magnetic fluid hyperthermia). Depending on the functionalization molecule and intrinsic morphological features, MNPs now cover a broad scope which the current review aims to overview. Considering the exponential expansion of the field, the current review will be limited to roughly the past three years.
Investigations into the magnetohydrodynamics of viscous fluids have become more important in recent years, owing to their practical significance and numerous applications in astro-physical and geo-physical phenomena. In this paper, the radial base function was utilized to answer fractional equation associated with fluid flow passing through two parallel flat plates with a magnetic field. The magnetohydrodynamics coupled stress fluid flows between two parallel plates, with the bottom plate being stationary and the top plate moving at a persistent velocity. We compared the radial basis function approach to the numerical method (fourth-order Range-Kutta) in order to verify its validity. The findings demonstrated that the discrepancy between these two techniques is quite negligible, indicating that this method is very reliable. The impact of the magnetic field parameter and Reynolds number on the velocity distribution perpendicular to the fluid flow direction is illustrated. Eventually, the velocity parameter is compared for diverse conditions α, Reynolds and position (y), the maximum of which occurs at α = 0.4. Also, the maximum velocity values occur in α=0.4 and Re=1000 and the concavity of the graph is less for α=0.8.
In this study, the thermal performance of moving porous fin wetted with hybrid nanofluid with different cross-sections in the presence of a magnetic field is investigated. As an innovation, three different cross-sections) trapezoidal, concave parabolic and convex (have been used. The Shape-factor effect of hybrid nanoparticles is also considered in the equations. After extracting the governing equations and converting the PDE equations to ODE by Similarity solution, the equations are solved by Akbari-Ganji's method. The boundary conditions are an insulated tip with a finite length, and thermal functions for heat transfer coefficient and conductivity have been assumed. The impacts of several characteristics on the dimensionless temperature are thoroughly investigated, including Peclet number, thermal conductivity parameter, emissivity parameter, heat transfer coefficient parameter, convective–conductive parameter, and radiative–conductive parameter. The results show that Akbari-Ganji's method has good accuracy in solving heat transfer equations related to moving porous fin. Also, increasing the Peclet number increases the dimensionless temperature, because increasing the Peclet number causes the fin to move faster.
Bioconvection plays an inevitable role in introducing sustainable and environment-friendly fuel cell technologies. Bio-mathematical modelling of such designs needs continuous refinements to achieve strong agreements in experimental and computational results. Actually, microorganisms transport a miscellaneous palette of ingredients in manufacturing industrial goods particularly in fertilizer industries. Heat transfer characteristics of molecular structure are measured by a physical phenomenon which is allied with the transpiration of heat within matter. Motivated by bio-inspired fuel cells involved in near-surface flow phenomena, in the present article, we examine the transverse swimming of motile gyrotactic microorganisms numerically in a rheological Jeffery fluid near a stretching wall. The leading physical model is converted in a nonlinear system of ODEs through proper similarity alterations. A numerical technique called shooting method with R-K Fehlberg is applied via mathematical software and graphical presentations are obtained. The influence of all relative physical constraints on velocity, temperature, concentration, and volume fraction of gyrotactic microorganisms is expressed geometrically. It is found that heat and mass flux at the surface as well as density of motile microorganism’s declines for Brownian motion and thermophoresis parameter. Comparison in tabular form is made with existing literature to validate the results for limiting cases with convective boundary conditions.
In this study, adsorption of lactoferrin (Lf) and bovine serum albumin (BSA) nanoparticles on pellicular two-layer agarose-nickel immobilized by reactive blue 4 dye-ligand ([email protected]) was investigated. [email protected] was prepared using the three-phase emulsion method. The dynamic light scattering was first employed to quantify size distribution of Lf and BSA nanoparticles. Then, scanning electron microscopy (SEM) and atomic force microscope (AFM), respectively, were used to characterize structures of the two types of nanoparticles and adsorbent beads. SEM and AFM images demonstrate that shapes of the nanoparticles are globular and relatively uniform, where no adhesions were observed. Finally, adsorption behaviors of both Lf and BSA nanoparticles on [email protected] in affinity chromatography were investigated, with focus on the adsorption kinetics. Influences of contact time, pH, and initial concentration were analyzed to investigate the adsorbent behaviors in the expanded bed column. The influence of contact time on adsorption of Lf versus BSA nanoparticles indicates that 4 h is enough to adsorb protein models equal to 45%. Results indicate that Lf nanoparticles have a higher rate of around 83% than that of BSA nanoparticles. The increases in pH have negative effect on adsorption while opposite trend was found for initial concentration. Adsorption isotherm results reveal that the Langmuir and Freundlich isotherm models fit both adsorption kinetics of Lf and BSA very well.
Owing to their safety, stability and controllability, diffusion flames have found extensive applications in medicine and power generation. Regarding the significance of recirculation impact on micro-combustors, an efficient method should be developed for better analysis of the micro-combustors performance. In this paper, an asymptotic method is developed to model diffusion flames propagation through a biofuel in counterflow configuration with the consideration of heat recirculation effect. The flame structure includes pre-heat, post-vaporization and oxidizer zones. Micron-sized lycopodium particles and air can be regarded as biofuel and oxidizer, respectively. Mass and energy conservation equations are investigated in each zone. For evaluation of the thermal recirculation impact, a specific term is included in the energy conservation equation. Furthermore, the effects of changes in the flame temperature, mass fraction of the gaseous fuel and oxidizer (relative to fuel and oxidizer Lewis numbers), mass particle content, particle radius and equivalence ratio were examined considering and ignoring the thermal recirculation effect. The results indicate that increase of heat recirculation coefficient will rise the flame temperature and shift the flame position to the fuel nozzle side. Also, consideration of thermal heat recirculation will enhance the gaseous fuel production in the pre-heat and post-vaporization zones.
Due to coal's vital role as a well-known fuel in electricity production worldwide, promising prediction of the behavior of this fuel in different combustible systems can be an effective prerequisite for augmentation of efficiency of coal-fuelled power plants. In this research, planar non-premixed combustion of moisty coal particles in counter-flow design is mathematically elucidated using an asymptotic concept. To develop a reliable model, preheat, drying, pyrolysis and oxidation processes are included. In the pyrolysis process, effects of produced char and gas are examined. In the flame region, homogeneous and heterogeneous reactions are considered. Mass and energy conservation equations are mathematically characterized to yield the temperature and mass fraction profiles of the fuel particles and oxidizer taking into account the porosity of the coal particles. A system of coupled governing equations are solved using Matlab and Mathematica software. Eventually, effects of crucial parameters including flame front temperature and position, strain rate, fuel and oxidizer mass fractions with Lewis number, and initial temperature are evaluated. Maximum temperature of the counter-flow non-premixed flame fed with coal particles with diameter of 20 µm is found to be 3097 K for fuel Lewis number of 0.3 for unity values of porosity factor and oxidizer Lewis number.
In-situ precipitation method is widely used and reported in the literature for the synthesis of iron oxide nanoparticles based on their applications in many fields. However, the rate of reaction and rate constant for the production of Magnetite Phase of iron oxide did not study in depth. Reaction rates are required to design a scale-up of the process. In this study, Magnetite phase of iron oxide nanoparticles (Fe3O4) are synthesized by the in-situ precipitation method, and the overall reaction rate is evaluated based on the concentration of Magnetite produced during the process. Further, X-ray diffraction, energy-dispersive X-ray spectroscopy and Raman spectroscopy are used to confirm the presence of a higher proportion of magnetite (Fe3O4) in the final product, which is responsible for more top magnetic properties 74.615 emu. Changes in morphology of these nanoparticles at different intervals of the reaction are reported by transmission electron microscope. The results showed that spherical nanoparticles synthesized at different intervals of the reaction have a very narrow range of particle size, i.e. 9–15 nm. Detailed analysis reveals the presence of a higher share of maghemite (Fe2O3) at the start of the reaction. However, maghemite eventually is converted to magnetite by the end of the reaction, thereby enhancing the magnetic strength of the nanoparticles.
In this article, we propose a numerical framework based on multiple relaxation time lattice Boltzmann model and novel discretization techniques for simulating compressible flows. Highly efficient finite difference lattice Boltzmann methods are employed to simulate one- and two-dimensional compressible flows. These numerical techniques are applied on the single- and multiple-relaxation-time (MRT) on the 16-discrete-velocity (Kataoka and Tsutahara Phys. Rev. E 69(5):056702, 2004) compressible lattice Boltzmann model. The Boltzmann equation is discretized via modified Lax-Wendroff (M-LW) and modified Total variation diminishing (M-TVD) schemes which have ability to damps oscillations at discontinuities, effectively. The results of compressible models are compared and validated with the well-known inviscid compressible flow benchmark test cases, so called Riemann problems. The proposed method shows its superiority over available techniques when compared to the analytical solutions. It is then used to solve two-dimensional inviscid compressible flow benchmarks, including regular shock reflection and Richtmyer-Meshkov instability (RM) problems to ensure its applicability for more complex problems. It is found that, the applied discretization techniques improve the stability of original LB models and enhance the robustness of compressible flow problems by preventing the formation of oscillation.
Currently, the most important preparation process for porous polymer membranes is the phase inversion process. While applied for several decades in industry, the mechanism that leads to diverse morphology is not fully understood today. In this work, we present time resolved experiments using light microscopy that indicate viscous fingering during the early stage of pore formation in porous polymer membranes. Numerical simulations using the smoothed particle hydrodynamics method are also performed based on Cahn-Hilliard and Navier-Stokes equations to investigate the formation of viscous fingers in miscible and immiscible systems. The comparison of pore formation characteristics in the experiment and simulation shows that immiscible viscous fingering is present; however, it is only relevant in specific preparation setups similar to Hele-Shaw cells. In experiments, we also observe the formation of Liesegang rings. Enabling diffusive mass transport across the immiscible interface leads to Liesegang rings in the simulation. We conclude that further investigations of Liesegang pattern as a relevant mechanism in the formation of morphology in porous polymer membranes are necessary.
Magnetite (Fe3O4) is one of the most important iron oxides due to its extensive range of application in various fields. The characteristics of magnetite can be considerably enhanced by reducing the particle size to the nanometer scale. When novel functions of nanoparticles are desired, it is necessary to have monodispersed or nearly monodispersed nanoparticles. Many synthesis methods have been proposed to produce monodispersed magnetite nanoparticles, including co-precipitation, sol-gel, hydrothermal and electrochemical methods. In this review, progress in the preparation of magnetite nanoparticles and their composites through the electrochemical method and the scale-up method are discussed.
Fullsize Image
Thermal plasma method has been used to process mild steel scrap for nanopowder synthesis by changing the operating current. The phase analysis of the product nanopowders was studied by X-ray diffraction and the chemical composition was studied by energy dispersive spectroscopy. The morphology, particle size and particle size distribution of the samples were investigated by field emission scanning electron microscope. In addition to the above, the magnetic properties of the samples were investigated by superconducting quantum interface device magnetometer and high temperature vibrating sample magnetometer (HTVSM). From this study, the results indicate that the processed nanopowders were magnetite and exhibit spherical morphology. The magnetic properties, such as, saturation magnetization (MS), coercivity (HC), and Curie temperature (Tc) were estimated. The M–H loops exhibited soft magnetism and samples corresponding to 60 and 70A showed the highest MS and HC, respectively. The Curie temperature was determined for the sample corresponding to 60A using HTVSM as 852 and 840 K from the heating and cooling curves, respectively. The outcome of the results suggests that thermal plasma is a contaminant-free process and is suitable for processing metal scrap.
Recently, iron oxide nanoparticles (NPs) have attracted much consideration due to their unique properties, such as superparamagnetism, surface-to-volume ratio, greater surface area, and easy separation methodology. Various physical, chemical, and biological methods have been adopted to synthesize magnetic NPs with suitable surface chemistry. This review summarizes the methods for the preparation of iron oxide NPs, size and morphology control, and magnetic properties with recent bioengineering, commercial, and industrial applications. Iron oxides exhibit great potential in the fields of life sciences such as biomedicine, agriculture, and environment. Nontoxic conduct and biocompatible applications of magnetic NPs can be enriched further by special surface coating with organic or inorganic molecules, including surfactants, drugs, proteins, starches, enzymes, antibodies, nucleotides, nonionic detergents, and polyelectrolytes. Magnetic NPs can also be directed to an organ, tissue, or tumor using an external magnetic field for hyperthermic treatment of patients. Keeping in mind the current interest in iron NPs, this review is designed to report recent information from synthesis to characterization, and applications of iron NPs.
Nanotechnologies are widely spreading in medicine to cancer detection and therapy. Modern anticancer therapies are based on the targeted delivery of magnetic nanoparticles (MNPs) into the tumor cells, causing specific tumor destruction. One of the applications of MNPs is treatment of cancer by different ways such as loading drugs onto MNPs and directed them into the tumor tissue.
Sol-gel chemistry offers a flexible approach to obtaining a diverse range of materials. It allows differing chemistries to be achieved as well as offering the ability to produce a wide range of nano-/micro-structures. The paper commences with a generalized description of the various sol-gel methods available and how these chemistries control the bulk properties of the end products. Following this, a more detailed description of the biomedical areas where sol-gel materials have been explored and found to hold significant potential. One of the interesting fields that has been developed recently relates to hybrid materials that utilize sol-gel chemistry to achieve unusual composite properties. Another intriguing feature of sol-gels is the unusual morphologies that are achievable at the micro- and nano-scale. Subsequently the ability to control pore chemistry at a number of different length scales and geometries has proven to be a fruitful area of exploitation, that provides excellent bioactivity and attracts cellular responses as well as enables the entrapment of biologically active molecules and their controllable release for therapeutic action. The approaches of fine-tuning surface chemistry and the combination with other nanomaterials have also enabled targeting of specific cell and tissue types for drug delivery with imaging capacity.
This review focuses on the recent development and various strategies in the preparation, microstructure, and magnetic properties of bare and surface functionalized iron oxide nanoparticles (IONPs); their corresponding biological application was also discussed. In order to implement the practical in vivo or in vitro applications, the IONPs must have combined properties of high magnetic saturation, stability, biocompatibility, and interactive functions at the surface. Moreover, the surface of IONPs could be modified by organic materials or inorganic materials, such as polymers, biomolecules, silica, metals, etc. The new functionalized strategies, problems and major challenges, along with the current directions for the synthesis, surface functionalization and bioapplication of IONPs, are considered. Finally, some future trends and the prospects in these research areas are also discussed.
Superparamagnetic iron oxide nanoparticles were synthesized by injecting ferrocene vapor and oxygen into an argon/helium DC thermal plasma. Size distributions of particles in the reactor exhaust were measured online using an aerosol extraction probe interfaced to a scanning mobility particle sizer, and particles were collected on transmission electron microscopy (TEM) grids and glass fiber filters for off-line characterization. The morphology, chemical and phase composition of the nanoparticles were characterized using TEM and X-ray diffraction, and the magnetic properties of the particles were analyzed with a vibrating sample magnetometer and a magnetic property measurement system. Aerosol at the reactor exhaust consisted of both single nanocrystals and small agglomerates, with a modal mobility diameter of 8–9 nm. Powder synthesized with optimum oxygen flow rate consisted primarily of magnetite (Fe3O4), and had a room-temperature saturation magnetization of 40.15 emu/g, with a coercivity and remanence of 26 Oe and 1.5 emu/g, respectively.
Samples of ferrofluids containing chemically stabilized nanoparticles of magnetite (Fe3O4) with tetramethylammonium hydroxide (TMAOH) were prepared by a direct reduction–precipitation method. The influences of aging time and temperature on the size and monodispersion characteristics of the produced nanoparticles were investigated. Transmission electron microscopy, powder X-ray diffraction, Fourier-transform infrared, and magnetization measurements with applied magnetic field up to 2 T were used to characterize the synthesized iron oxides. Raising the temperature of the synthesized material in autoclave affects positively the monodispersion of the nanoparticles, but it was not found to significantly influence the size itself of individual particles.
Knowledge of the mechanism of combustion zone propagation during dust explosion is of great importance to prevent damage caused by accidental dust explosions. In this study, the temperature profile across the combustion zone propagating through an iron particle cloud is measured experimentally by a thermocouple to elucidate the propagation mechanism. The measured temperature starts to increase slowly at a position about 5 mm ahead of the leading edge of the combustion zone, increases quickly at a position about 3 mm ahead of the leading edge, reaches a maximum value near the end of the combustion zone, and then decreases. As the iron particle concentration increases, the maximum temperature increases at lower concentration, takes a maximum value, and then decreases at higher concentration. The relation between the propagation velocity of the combustion zone and the maximum temperature is also examined. It is found that the propagation velocity has a linear relationship with the maximum temperature. This result suggests that the conductive heat transfer is dominant in the propagation process of the combustion zone through an iron particle cloud.
Iron oxide nanoparticles, to be used in a health effects study, were synthesized in a H2/air diffusion flame and characterized by transmission electron microscopy, X-ray diffraction, surface area measurement, inductively coupled plasma mass spectrometry, and a spectrophotometric speciation method. The nanoparticles exhibited the maghemite (γ -Fe2O3) crystal structure and contained only trivalent iron. There were two size modes in the particles. The large size mode contained crystalline, non-agglomerated particles with a median diameter of approximately 45 nm; the small size mode contained particles that were in the size range of 3–8 nm and were mostly amorphous. Depending on the value taken for the small particle size, the small mode accounted for 73–82% of the particle surface area. The particles in the small size mode were likely formed from the vapor of FeO and Fe.
The chemical routes for the synthesis of superparamagnetic iron oxide nanoparticles, fluid stabilization, surface modification for grafting biomolecules, and the different techniques for structural and physicochemical characterization have been summarized. Examples of biomedical applications in the field of molecular imaging and cell targeting are also given.
Magnetic nanoparticles (mNPs) ranging from the nanometre and micrometre scale have been widely applied in recent years in the area of biomedicine. They contain unique magnetic properties and due to their size can function at a cellular level, making them attractive candidates for cell labelling, imaging, tracking and as carriers. A recent surge of interest in nanotechnology has boosted the breadth and depth of the nanoparticle research field. This review aims to supplement a previously published review in 2003 and address more recent advances in the uses and bioapplications of mNPs and future interesting perspectives.
Interfacial-driven flows are important phenomena in many processes. In this article, we present a Smoothed Particle Hydrodynamics (SPH) model for thermo-capillary flow driven by gradients of the surface tension. The model is based on the continuum surface force (CSF) approach including Marangoni forces. An incompressible SPH approach using (i) density-invariant divergence-free (DIDF), (ii) corrected SPH and (iii) particle shifting approaches for multi-phase systems is used for accurate results. We carefully validate the proposed model using several test cases. First, we demonstrate the effects of corrected SPH and particle shifting approaches using Taylor-Green vortex. Then, we study single-phase flow problems to validate correct implementation of boundary conditions, momentum and energy balance using lid-driven cavity, diffusive transport problem, and buoyancy-driven cavity test cases. Afterward, we investigate different multi-phase flow problems to validate normal and tangential component of the surface tension. Finally, we apply the model to thermo-capillary rise of a droplet due to a temperature gradient. We present a convergence study and compare the results with their counterparts obtained from OpenFoam software as well as Finite Volume method (FVM) reference from literature. We demonstrate that the proposed model is very accurate for thermo-capillary flow. The simulation results of the current SPH approach will be available online for the community.
Non-premixed flames are extensively used in different industrial combustion systems such as gas turbines and coal furnaces. Therefore, reliable theoretical modelling of these flames is indispensable. The purpose of this study is to develop a comprehensive analytical model for counter-flow non-premixed flames employing volatile biomass particles as the fuel. In order to present a promising and accurate analysis for the flame structure and propagation, preheat, drying, vaporization, reaction and oxidizer zones are presumed. In the current analytical modelling, a non-asymptotic approach is used. In this regard, finite thicknesses are considered for the drying and vaporization zones. Lycopodium particles and air are taken as the biofuel and oxidizer, respectively. It is assumed that the gaseous fuel yielded from lycopodium particles is methane. Dimensionless parameters are defined and then non-dimensionalized forms of governing equations including mass and energy conservation equations are derived taking into account appropriate boundary and jump conditions for each zone. The equations are solved by Mathematica and Matlab software. Eventually, the impacts of fuel and oxidizer Lewis numbers, mass particle concentration parameter, equivalence ratio, lycopodium initial temperature on the flow strain rate, flame temperature, flame position and gaseous fuel and oxidizer mass fractions are elaborately examined.
Through high-resolution direct numerical simulations, the present study aims to investigate several laminar-to-turbulent transition scenarios in the presence of wall heat transfer for supersonic boundary layers over strongly heated/cooled and adiabatic flat plates. The laminar boundary layer is tripped using a suction and blowing technique with a single-frequency, multiple-spanwise wavenumber excitation. The results are evaluated and compared with linear stability theory to isolate the effect of wall heat transfer, as well as forcing parameters, on the transition. It was found that increasing the disturbance amplitude as well as perturbation frequency moves the transition upstream. Also, the effect of wall heating was seen to stabilize the flow and to postpone the transition, contrary to the wall cooling.
In the present article an analytical approach is employed to study the counterflow non-premixed dust flame structure in air. Lyco-podium is assumed as the organic fuel in in this paper. First, it is presumed that the fuel particles vaporize in a thin zone to form a gaseous fuel to react with the oxidizer. The reaction rate is presumed to be of the Arrhenius type in first order respect to oxidizer and fuel. Mass conservation equations of dust particles, oxidizer, gaseous fuel and the energy conservation equation for non-unity Lewis numbers of oxidizer and fuel are presented as the governing equations. Boundary conditions are applied for each zone for the purpose of solving the governing equations analytically. The flame temperature in terms of oxidizer and fuel’s Lewis numbers is calculated. Furthermore, the variation of flame position based on the fuel and oxidizer’s Lewis numbers is evaluated .Also, mass fraction and temperature profiles of oxidizer and fuel are presented. In addition, the variation of the ratio of critical extinction values of strain rates as a function of non-unity Lewis numbers of oxidizer and fuel to the unity Lewis numbers of them is investigated.
Preface.- Nomenclature.- Fuel.- Thermodynamics of Combustion.- Chemical Kinetics.- Review of Transport Equations and Properties.- Ignition Phenomena.- Premixed Flames.- Non-Premixed Flames (Diffusion Flames).- Droplet Evaporation and Combustion.- Emissions.- Premixed Piston IC Engines.- Diesel Engines.- Labs.- Properties of Fuels.- Properties of Air at 1 atm.- Properties of Ideal Combustion Gases.- Elementary Reaction Mechanisms.- Summary of Limits of Flammability.- Minimum Ignition Energy.- Antoine Equation.- Flash Points for Common Fuels.- Properties of Some Alcohol Fuels and Ammonia
Iron oxide nanoparticles are one of the most versatile and safe nanomaterials used in medicine. Recent progress in nanochemistry enables fine control of the size, crystallinity, uniformity, and surface properties of iron oxide nanoparticles. In this review, the synthesis of chemically designed biocompatible iron oxide nanoparticles with improved quality and reduced toxicity is discussed for use in diverse biomedical applications. High-quality iron oxide nanoparticles, synthesized on a large scale via green chemistry and a chemically well-designed biocompatible shell, have great potential as a new iron-oxide-based nanomedicine.
A novel approach to prepare magnetic polymeric nanoparticles by synthesis of the magnetite core and polymeric shell in a single inverse microemulsion is reported. Stable magnetic nanoparticles colloid dispersion with narrow size distribution can thus be produced. The microemulsion seed copolymerization of methacrylic acid, hydroxyethyl methacrylate, and cross-linker results in a stable hydrophilic polymeric shell of the nanoparticles. The preparation of the nanoparticles was carried out also by the two-stage microemulsion process and the seed precipitation polymerization. The particle size was varied in the range 80−320 nm by changing of the monomer concentration and water/surfactant ratio. The magnetic properties and the size distribution of the nanoparticles synthesized by these three methods were compared. The polymeric nanoparticles synthesized in single microemulsion have superparamagnetic properties and the narrowest size distribution.
Controlled release of drugs from nanostructured functional materials, especially nanoparticles (NPs), is attracting increasing attention because of the opportunities in cancer therapy and the treatment of other ailments. The potential of magnetic NPs stems from the intrinsic properties of their magnetic cores combined with their drug loading capability and the biochemical properties that can be bestowed on them by means of a suitable coating. Here we review the problems and recent advances in the development of magnetic NPs for drug delivery, focusing particularly on the materials involved.
Magnetic nanoparticles with appropriate surface coatings are increasingly being used clinically for various biomedical applications, such as magnetic resonance imaging, hyperthermia, drug delivery, tissue repair, cell and tissue targeting and transfection. This is because of the nontoxicity and biocompatibility demand that mainly iron oxide-based materials are predominantly used, despite some attempts to develop 'more magnetic nanomaterials' based on cobalt, nickel, gadolinium and other compounds. For all these applications, the material used for surface coating of the magnetic particles must not only be nontoxic and biocompatible but also allow a targetable delivery with particle localization in a specific area. Magnetic nanoparticles can bind to drugs and an external magnetic field can be applied to trap them in the target site. By attaching the targeting molecules, such as proteins or antibodies, at particles surfaces, the latter may be directed to any cell, tissue or tumor in the body. In this review, different polymers/molecules that can be used for nanoparticle coating to stabilize the suspensions of magnetic nanoparticles under in vitro and in vivo situations are discussed. Some selected proteins/targeting ligands that could be used for derivatizing magnetic nanoparticles are also explored. We have reviewed the various biomedical applications with some of the most recent uses of magnetic nanoparticles for early detection of cancer, diabetes and atherosclerosis.
New way to produce magnetite nanoparticles at low temperature
- F Mata-Pérez
- J R Martínez
- A L Guerrero
- G Ortega-Zarzosa