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| [[File:Magnetization curves.svg|thumb|Magnetization curves of 9 ferromagnetic materials, showing saturation. 1.Sheet steel, 2.Silicon steel, 3.Cast steel, 4.Tungsten steel, 5.Magnet steel, 6.Cast iron, 7.Nickel, 8.Cobalt, 9.Magnetite<ref>{{cite manual|first=Charles |last=Steinmetz |year=1917|title=Theory and Calculation of Electric Circuits |publisher=McGraw-Hill|ref=harvnb|section=fig. 42}}</ref>]]
| | When faced with an impending exam, students need to learn to create a schedule for themselves. When it comes to an anxiety disorder and more importantly treating it, we can mean several things by natural remedies. A simple thirty minute walk every day will do wonders for your body and anxiety if you eat right. You can take this medication 30 to 60 minutes before going into a stressful situation. Some negative thoughts and attitudes of women that cause stress and depression: fear of becoming older, facing unwanted responsibilities, reacting negatively to intolerant husbands who might insist on sex, feeling of unimportant, coping with all the physical changes, etc. <br><br>The brain requires folic acid to function properly. And these therapy consequences are not dangerous by any means, you're just loosing fat, not loosing electrolytes. Reassure each child by repeating often that parents will return at the end of the day. Come up with unique ways to help you overcome whatever personal problems. These range from medication to therapy and alternative medicines. <br><br>Phobias can be two major types: social phobia and specific phobia. (( Anxiety is a psychological and physiological state characterized by -. Do you need to rely on prescription medicines for pain relief. Again, I ask that you refer to my article Rescue Dog Training - Crate Training is Kind not Cruel which will explain how to acclimate your dog to spending time in the crate. And don’t forget to watch what you eat, quit smoking, and quit drinking so much coffee. <br><br>Deep breathing is considered a far healthier way of breathing and encourages your body to improve its overall oxygen flow, which in turn cuts down on anxiety related symptoms. Nothing contributes more to anxiety like “what if” statements, when in reality we have to concentrate on “what is”. The increase in retail and food service sales is expected based on declining level of financial anxiety resulting from improvement in GDP and increasing consumer expenditure in the third quarter of this year. Each fixed thought that you have solidifies the energy and limits your ability to generate in that area and for something different to show up in your life with ease. Anxiety disorders are one of the primary mental health problems affecting children today. <br><br>Of course, obviously, an anxiety attack is not a stroke, and an anxiety attack is not a heart attack. Such experiences include abuse or neglect, emotional deprivation, and the loss of or separation from one''. Later in life, as adults, an upsetting, stressful or traumatic situation may trigger this negative thinking and set the stage for a depressive or anxiety disorder. The child may also experience shortness of breath, choking or smothering sensations, pounding heartbeat, chest pain, nausea, lightheadedness, trembling and shaking, and fear of losing their mind. They may not interrupt, but they don't pay attention, and have no idea what's going on.<br><br>In case you loved this short article and you wish to get more information relating to anxiety and stress management institute ([http://www.stress-lavoro-correlato.info/sitemap/ http://www.stress-lavoro-correlato.info/]) i implore you to check out the page. |
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| Seen in some [[magnetic]] materials, '''saturation''' is the state reached when an increase in applied external [[magnetic field]] ''H'' cannot increase the [[magnetization]] of the material further, so the total [[magnetic flux density]] ''B'' levels off. It is a characteristic particularly of [[ferromagnetic]] materials, such as [[iron]], [[nickel]], [[cobalt]] and their alloys.
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| ==Description==
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| Saturation is most clearly seen in the ''magnetization curve'' (also called ''BH'' curve or [[hysteresis]] curve) of a substance, as a bending to the right of the curve (see graph at right). As the ''H'' field increases, the ''B'' field approaches a maximum value [[asymptote|asymptotically]], the saturation level for the substance. Technically, above saturation, the ''B'' field continues increasing, but at the [[paramagnetic]] rate, which is 3 [[Orders of magnitude (magnetic field)|orders of magnitude]] smaller than the ferromagnetic rate seen below saturation.<ref name=Bozorth>{{cite book
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| |last = Bozorth
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| |first = Richard M.
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| |title = Ferromagnetism
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| |publisher = [[Wiley-IEEE Press]]
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| |year = 1993
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| |origyear = Reissue of 1951 publication
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| |series = AN IEEE Press Classic Reissue
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| |isbn = 0-7803-1032-2
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| |ref = harvnb
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| }}</ref>
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| The relation between the [[magnetizing field]] ''H'' and the [[magnetic field]] ''B'' can also be expressed as the magnetic [[Permeability (electromagnetism)|permeability]]: <math>\mu = B / H</math> or the ''relative permeability'' <math>\mu_r = \mu/\mu_0</math>, where <math>\mu_0</math> is the [[vacuum permeability]]. The permeability of ferromagnetic materials is not constant, but depends on ''H''. In saturable materials the relative permeability increases with ''H'' to a maximum, then as it approaches saturation inverts and decreases toward one.<ref name=Bozorth/><ref>{{cite book | |
| | last = Bakshi
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| | first = V.U.
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| | authorlink =
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| | coauthors = U.A.Bakshi
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| | title = Basic Electrical Engineering
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| | publisher = Technical Publications
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| | year = 2009
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| | location =
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| | pages = 3.31
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| | url = http://books.google.com/books?id=N9hnAJxFcaEC&pg=SA3-PA31&dq=ferromagnetic+permeability+above+saturation&hl=en&ei=0g6dTtajLu3YiQL4sa3nCQ&sa=X&oi=book_result&ct=result&resnum=10&ved=0CFwQ6AEwCQ#v=onepage&q=ferromagnetic%20permeability%20above%20saturation&f=false
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| | doi =
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| | pages=3-31
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| | isbn = 81-8431-334-9}}</ref>
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| Different materials have different saturation levels. For example, high permeability iron alloys used in transformers reach magnetic saturation at 1.6 - 2.2 [[tesla (unit)|tesla]]s (T),<ref>{{cite book|editor1-last=Laughton|editor1-first=M. A.|editor2-last=Warne|editor2-first=D. F.|title=Electrical Engineer's Reference Book|edition= Sixteenth|publisher=Newnes|year=2003|isbn=0-7506-4637-3|ref=harvnb|chapter=8}}</ref> whereas [[ferrite magnet|ferrite]]s saturate at 0.2 - 0.5 T.<ref name=Chikazumi>{{cite manual
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| |last = Chikazumi
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| |first = Sōshin
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| |title = Physics of Ferromagnetism
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| |publisher = [[Clarendon Press]]
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| |year = 1997
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| |isbn = 0-19-851776-9
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| |ref = harvnb
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| |section=table 9.2
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| }}</ref> Some [[amorphous metal|amorphous]] alloys saturate at 1.2-1.3 T.<ref>{{cite patent
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| | country = USA
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| | number = 5126907
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| | title = Thin film magnetic head having at least one magnetic core member made at least partly of a material having a high saturation magnetic flux density
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| | gdate = 1992
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| | inventor = Yoshihiro Hamakawa, Hisashi Takano, Naoki Koyama, Eijin Moriwaki, Shinobu Sasaki, Kazuo Shiiki
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| | ref=harvnb
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| }}</ref> [[Mu metal]] saturates at around 0.8 T.<ref>{{cite web|url=http://www.kjmagnetics.com/blog.asp?p=shielding-materials|title=Shielding Materials|publisher=K+J Magnetics|accessdate=2013-05-07}}</ref><ref>{{cite web|url=http://mumetal.co.uk/2009/04/03/mumetal-is-one-of-a-family-of-three-nickel-iron-alloys/|title=Mumetal is one of a family of three Nickel-Iron alloys|publisher=mumetal.co.uk|accessdate=2013-05-07}}</ref>
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| [[File:Permeability of ferromagnet by Zureks.svg|thumb|Due to saturation, the [[magnetic permeability]] μ<sub>f</sub> of a ferromagnetic substance reaches a maximum and then declines]]
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| ==Explanation==
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| {{Further2|[[Ferromagnetism]]}}
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| Ferromagnetic materials (like iron) are composed of microscopic regions called [[magnetic domain]]s, that act like tiny [[permanent magnet]]s that can change their direction of magnetization. Before an external magnetic field is applied to the material, the domains are oriented in random directions. Their tiny [[magnetic field]]s are oriented in random directions and cancel each other out, so the material has no significant magnetic field. When an external magnetizing field ''H'' is applied to the material, it penetrates the material and aligns the domains, causing their tiny magnetic fields to turn and align parallel to the external field, adding together to create a large magnetic field ''B'' which extends out from the material. This is called [[magnetization]]. The stronger the external magnetic field ''H'', the more the domains align yielding a higher magnetic flux density ''B''. Saturation occurs when practically all the domains are lined up, so further increases in ''H'' can't increase ''B'' beyond the increment that would be caused in a nonmagnetic material, in other words, cannot cause further alignment of the domains.
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| ==Effects and uses==
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| Saturation limits the maximum magnetic fields achievable in ferromagnetic-core [[electromagnet]]s and [[transformer]]s to around 2 T, which puts a limit on the minimum size of their cores. This is one reason why high power motors, generators, and [[Electric utility|utility]] transformers are physically large; because they must have large magnetic cores.
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| In [[electronic circuit]]s, transformers and [[inductor]]s with ferromagnetic cores operate [[Linear circuit|nonlinearly]] when the current through them is large enough to drive their core materials into saturation. This means that their [[inductance]] and other properties vary with changes in drive current. In [[linear circuit]]s this is usually considered an unwanted departure from ideal behavior. When [[Alternating current|AC]] [[Signal (circuit theory)|signals]] are applied, this nonlinearity can cause the generation of [[harmonic]]s and [[intermodulation distortion]]. To prevent this, the level of signals applied to iron core inductors must be limited so they don't saturate. To lower its effects, an air gap is created in some kinds of transformer cores.<ref>{{cite web |url=http://sound.westhost.com/xfmr2.htm#s131 |title=Transformers - The Basics (Section 2) |first=Elliott |last= Rod |date=May 2010 |work= Beginner's Guide to Transformers|publisher= Elliott Sound Products |accessdate=2011-03-17| ref=harvnb}}</ref> The ''saturation current'', the current through the winding required to saturate the magnetic core, is given by manufacturers in the specifications for many inductors and transformers.
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| On the other hand, saturation is exploited in some electronic devices. Saturation is employed to limit current in ''saturable-core transformers'', used in [[arc welding]], and ferroresonant transformers which serve as [[voltage regulator]]s. When the primary current exceeds a certain value, the core is pushed into its saturation region, limiting further increases in secondary current. In a more sophisticated application, [[saturable core inductor]]s and [[magnetic amplifier]]s use a DC current through a separate winding to control an inductor's [[Electrical impedance|impedance]]. Varying the current in the control winding moves the operating point up and down in the saturation curve, controlling the AC current through the inductor. These are used in variable [[fluorescent light]] [[ballast (electrical)|ballast]]s, and power control systems.<ref>{{cite manual
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| |last = Choudhury
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| |first = D. Roy
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| |title = Modern Control Engineering
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| |publisher = Prentice-Hall of India
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| |year = 2005
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| |isbn = 81-203-2196-0
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| |ref = harvnb
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| |section=2.9.1}}</ref>
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| <!-- Any physicist cares to say more? -->
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| ==See also==
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| * [[Ferromagnetism]]
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| * [[Magnetic domain]]
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| * [[Magnetic reluctance]]
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| * [[Permeability (electromagnetism)|Permeability]]
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| * [[Permendur|Permendur/Hiperco]]
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| ==References==
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| {{Reflist}}
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| {{DEFAULTSORT:Saturation (Magnetic)}}
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| [[Category:Magnetism]]
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When faced with an impending exam, students need to learn to create a schedule for themselves. When it comes to an anxiety disorder and more importantly treating it, we can mean several things by natural remedies. A simple thirty minute walk every day will do wonders for your body and anxiety if you eat right. You can take this medication 30 to 60 minutes before going into a stressful situation. Some negative thoughts and attitudes of women that cause stress and depression: fear of becoming older, facing unwanted responsibilities, reacting negatively to intolerant husbands who might insist on sex, feeling of unimportant, coping with all the physical changes, etc.
The brain requires folic acid to function properly. And these therapy consequences are not dangerous by any means, you're just loosing fat, not loosing electrolytes. Reassure each child by repeating often that parents will return at the end of the day. Come up with unique ways to help you overcome whatever personal problems. These range from medication to therapy and alternative medicines.
Phobias can be two major types: social phobia and specific phobia. (( Anxiety is a psychological and physiological state characterized by -. Do you need to rely on prescription medicines for pain relief. Again, I ask that you refer to my article Rescue Dog Training - Crate Training is Kind not Cruel which will explain how to acclimate your dog to spending time in the crate. And don’t forget to watch what you eat, quit smoking, and quit drinking so much coffee.
Deep breathing is considered a far healthier way of breathing and encourages your body to improve its overall oxygen flow, which in turn cuts down on anxiety related symptoms. Nothing contributes more to anxiety like “what if” statements, when in reality we have to concentrate on “what is”. The increase in retail and food service sales is expected based on declining level of financial anxiety resulting from improvement in GDP and increasing consumer expenditure in the third quarter of this year. Each fixed thought that you have solidifies the energy and limits your ability to generate in that area and for something different to show up in your life with ease. Anxiety disorders are one of the primary mental health problems affecting children today.
Of course, obviously, an anxiety attack is not a stroke, and an anxiety attack is not a heart attack. Such experiences include abuse or neglect, emotional deprivation, and the loss of or separation from one. Later in life, as adults, an upsetting, stressful or traumatic situation may trigger this negative thinking and set the stage for a depressive or anxiety disorder. The child may also experience shortness of breath, choking or smothering sensations, pounding heartbeat, chest pain, nausea, lightheadedness, trembling and shaking, and fear of losing their mind. They may not interrupt, but they don't pay attention, and have no idea what's going on.
In case you loved this short article and you wish to get more information relating to anxiety and stress management institute (http://www.stress-lavoro-correlato.info/) i implore you to check out the page.