1.1 PRELUDE:
The phenomenon of ferromagnetism is associated only with the solid state of matter; like iron, nickel, cobalt and some rare earth metals and their alloys. Thus, up to now, there is no intrinsic homogeneous fluid having ferromagnetic properties; although, theories admit the possibility of ferromagnetism in the liquid state, and suggest that there is no inherent reason why they should not exist [1-3,5]. Ferromagnetism occurs when paramagnetic ions in a solid lock together in such a way that their spins all point (on the average) in the same direction . At a certain temperature this locking breaks down and ferromagnetic materials become paramagnetic. This transition temperature is called the Curie point (TC), which is invariably well below the melting point of the corresponding material [1,8,12].
1.2 MAGNETIC FLUIDS:
Magnetic fluids ( MF ) are stable colloidal suspensions of ultrafine ferro- or ferri- magnetic particles ( D100Ao ), coated with a surfactant like oleic acid, in a suitable liquid carriers such as Isopar-M, kerosene, decalin, etc., [1,2].
The idea of MF was put forward independently and almost simultaneously by several investigators. The first prepared MF was developed by Stephen Papell of the National Aeronautics and Space Administration (NASA) in the early 1960s. After that, Ronald E. Rosensweig and his colleagues succeeded in formulating MFs that were 10 times as strong magnetically as Papell`s original MF [1].
The special feature of magnetic fluids is given by the fact, that they combine normal liquid behavior with superparamagnetic properties, as will be discussed later. The possibility of magnetic fluid control gave rise to the development of many technical applications in our everyday life [1-3].
Mixtures are classified into three kinds: colloidal suspensions, suspensions, and solutions, and one of the principal features that differentiate one kind of mixture from another is the size of the particles [6]. Colloidal suspensions (also called colloids) are mixtures that are intermediate between solutions and suspensions. Typically the radius of the particle is of the order 100Ao. Since this is much smaller than the size of a single magnetic domain in bulk solids, which is about , the magnetization of the individual particle is saturated, but the direction of the magnetic moment is subject to thermal agitation [1,2,5]. The particles used are commonly Fe3O4, Fe, Co and Ni.
MF is a two-phase system with three components, which combines magnetic properties, carried by the solid magnetic fine particles, with fluidity of the carrier liquid.
Furthermore, AMR should be recognized as the combined solid -fluid system, whereby, in essence, a temperature gradient is established throughout the AMR and a fluid is used to transfer heat from the cold end to the hot. This subtle but important idea produced a new magnetic cycle distinct from Carnot, Ericsson, Brayton, or Stirling [6].
The purpose of this lab was to investigate which additive(s) will create the longest lasting oil-in-water emulsion.
be sufficient to keep pace with increasing demand of the electrical energy of the world.
The Magnet certification of the American Nurses Credentialing Center(ANCC), mandates that nurses utilize research and evidence base practice to improve the safe delivery of patient care (Stanley, 2011). Due to the cost of “application fees, appraiser fees, site visit costs, and document preparation” that range from $46,000 to $251,000, some institutions have to rethink Magnet status due to its financial implications (Drenkard, 2010). Despite the initial and maintenance costs of the Magnet certification, evidence suggests the expenses may be offset within couple years through higher net inpatient revenue (Jayawardhana, Welton, & Lindrooth, 2014).
Magnetism is very useful in our daily life. A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. In addition, magnetic field is a region which a magnetic material experiences a force as the result of the presence of a magnet or a current carrying conductor. Current carrying conductors also known as wire. As we know there have north pole and south pole of a magnet. If same pole of magnet approaches each other, there will repel each other. In contrast, if different pole of magnet approaches each other, they will attract. These are same with the electric charge, if same charge it will repel, different charge it will attract. Although magnets and magnetism were known much earlier, the study of magnetic fields began in 1269 when French scholar Petrus Peregrinus de Maricourt mapped out the magnetic field on the surface of a spherical magnet using iron needles [search from Wikipedia]. Noting that the resulting field lines crossed at two points he named those points 'poles' in analogy to Earth's poles. Each magnet has its own magnetic field which experiences a force as the result of the presence of a magnet and magnetic field has made up of magnetic field lines. The properties of magnetic field lines is it begin at the north pole and end at the south pole. The north pole always flow out while south pole always flow in. The closer the magnetic field lines, the strength of magnetic field increases. Furthermore, these line cannot cross each other. Ferromagnetism is the basic mechanism by which certain materials (such as iron) form permanent magnets, or are attracted to magnets. Ferromagnetic materials...
Pure iron has a hardness that ranges from 4 to 5. It is soft and ductile. Iron can be easily magnetized at ordinary temperatures and at 790°C the magnetic property disappears. Pure iron melts at about 1535°C, boils at 2750°C, and has a specific gravity of 7.86. Chemically, iron is an active metal. When exposed to humid air, iron forms a reddish-brown, flaky, decay known as rust.
Liquid cores create a magnetic field. Mercury’s three layers are a rocky silicate crust, solid rocky silicate mantle, and a hot liquid iorn-nickle core. The core makes up 75% of its diameter. Scientists did not think that is was possible for the core to be liquid because over the years mercury’s rotation has slowed down dramatically. They thought that it would of been hardened by now.
The MRI works by using hydrogen atoms’ magnetic properties within the human body to produce high quality images. These protons of the hydrogen atoms can be look upon as bar magnets, in normal situations, they will flow inside...
Schultz, James. "Force Fields and 'Plasma' Shields Get Closer to Reality." Technology 25 July 2000: 20 pars. Web. 25 Oct. 2010. .
The development of superconductors has been a working progress for many years and some superconductors are already in use, but there is always room for improvement. In 1911, Dutch physicist Heike Kamerlingh Onnes first discovered superconductivity when he cooled mercury to 4 degrees K (-452.47º F / -269.15º C). At this temperature, mercury’s resistance to electricity seemed to disappear. Hence, it was necessary for Onnes to come within 4 degrees of the coldest temperature that is theoretically attainable to witness the phenomenon of superconductivity. Later, in 1933 Walter Meissner and Robert Ochsenfeld discovered that a superconducting material will repel a magnetic field. A magnet moving by a conductor induces currents in the conductor, which is the principle upon which the electric generator operates. However, in a superconductor the induced currents exactly mirror the field that would have otherwise penetrated the superconducting material - causing the magnet to be repulsed- known today as the “Meissner effect.” The Meissner effect is so strong that a magnet can actually be levitated over a superconductive material, which increases the use of superconductors. After many other superconducting elements, compounds, and theories related to superconductivity were developed or discovered a great breakthrough was made. In 1986, Alex Muller and Georg Bednorz invented a ceramic substance which superconducted at the highest temperature then known: 30 K (-243.15º C). This discovery was remarkable because ceramics are normally insulators – they do not conduct electricity well. Since their discovery the highest temperature for superconductivity to occur is 138 K (-130.15º C).
Temperature has a large effect on particles. Heat makes particles energized causing them to spread out and bounce around. Inversely the cold causes particles to clump together and become denser. These changes greatly F magnetic the state of substances and can also influence the strength of magnetic fields. This is because it can alter the flow of electrons through the magnet.
The Earth’s magnetic field is a major component to exploring the earth. The north and the south poles have always been a guide for travelers. Using compasses, the direction of the north pole and the south pole has always been provided by the magnetic force of the magnetic field. What many people do not know though is the earth’s magnetic field provides way more than that. The magnetic field, also known as the magnetosphere, protects us from all kinds of harmful substances. Some of these substances include solar wind and harmful radiation from the sun. The magnetosphere also protects the atmosphere, which protects us.
In this lab, the law of conservation of matter is involved, which is the law that matter is conserved, it can’t be created or destroyed. This is used in our lab because after separation, the mass of the three substances combined should equal the original mixture. There are also three states of matter that are used in this lab, solid, liquid, and gas. The iron filings and sand are solid, the salt water solution is a liquid, and when the water evaporates, it is a gas. To separate the mixture we were given, we needed to use three different separation methods. These consist of magnetism, filtration, and evaporation. The first is magnetism, which is the force that can attract or repel objects. We used the magnet to
A magnet is a solid object, usually made of metal iron, which has the ability to attract other materials (e.g., iron, steel, cobalt and nickel) within a magnetic field.