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| {{dablink|meV, keV, MeV, GeV, TeV and PeV redirect here. For other uses, see [[MEV (disambiguation)|MEV]], [[KEV (disambiguation)|KEV]], [[GEV (disambiguation)|GEV]], [[TEV (disambiguation)|TEV]] and [[PEV (disambiguation)|PEV]].}}
| | Probably you have previously seen an individual discuss leptin yet failed to fully understand what it is. There are a lot of hormones which help modulate energy balance inside the human body which include appetite, metabolism and hunger. Leptin, a hormone which takes on a vital function in managing energy intake along with energy output, may be one of the most critical hormones in your body which will ascertain your well being and life. <br><br> |
| In [[physics]], the '''electron volt''' (symbol '''eV'''; also written '''electronvolt'''<ref>[http://goldbook.iupac.org/E02014.html IUPAC Gold Book], p. 75</ref><ref>[http://www.bipm.org/en/si/si_brochure/chapter4/table7.html ''SI brochure''], Sec. 4.1 Table 7</ref>) is a unit of [[energy]] equal to approximately {{val|1.6|e=-19}} [[joule]] (symbol J). By definition, it is the amount of energy gained (or lost) by the charge of a single [[electron]] moved across an [[electric potential|electric]] [[potential difference]] of one [[volt]]. Thus it is 1 [[volt]] (1 joule per [[coulomb]], {{val|1|u=J/C}}) multiplied by the [[elementary charge]] (''e'', or {{val|1.602176565|(35)|e=-19|ul=C}}). Therefore, one electron volt is equal to {{val|1.602176565|(35)|e=-19|ul=J}}.<ref name="NIST">http://physics.nist.gov/constants</ref> Historically, the electron volt was devised as a standard unit of measure through its usefulness in [[Particle accelerator#Electrostatic particle accelerators|electrostatic particle accelerator]] sciences because a particle with charge ''q'' has an energy {{nowrap|1=''E'' = ''qV''}} after passing through the potential ''V''; if ''q'' is quoted in integer units of the [[elementary charge]] and the terminal bias in volts, one gets an energy in eV.
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| The electron volt is not an [[International System of Units|SI unit]], and thus its value in SI units must be obtained experimentally.<ref>http://physics.nist.gov/cuu/Units/outside.html</ref> Like the [[elementary charge]] on which it is based, it is not an independent quantity but is equal to {{nowrap|1 {{sfrac|J|C}} {{sqrt|2[[Planck constant|''h'']][[fine structure constant|''α'']] / [[magnetic constant|''μ''<sub>0</sub>]][[speed of light|''c''<sub>0</sub>]]}}}}. It is a common [[unit of energy]] within physics, widely used in [[Solid-state physics|solid state]], [[Atomic physics|atomic]], [[Nuclear physics|nuclear]], and [[particle physics]]. It is commonly used with the [[SI prefix]]es milli-, kilo-, mega-, giga-, tera-, peta- or exa- (meV, keV, MeV, GeV, TeV, PeV and EeV respectively). Thus meV stands for milli-electron volt.
| | This hormone activates the leptin receptors inside the hypothalamus which is a key process to manage body weight. While leptin is thought to be as a satiety hormone which the fat cells make, it doesn't suggest that those with far more [https://Www.vocabulary.com/dictionary/body+fat body fat] cells have got more leptin which tends to help them eat less and also weigh much less. It basically doesn't work that way. <br><br>Data reveal that for individuals with corresponding body mass index, women have got leptin levels which is three to four times greater than men. They are affected not only by body fat but also by simply how much a person feeds on. Leptin levels seem to correspond strongly to the levels of blood sugar.<br><br>What are the downfalls of higher leptin levels? You may have thought about [http://www.leanhealthyandwise.com leptin hormone]. Leptin by nature can easily contribute to body tissue and organ inflammation. The greater the amount of body fat you have, the more leptin you produce. Resistance to leptin is another growing concern. With an excess of nonstop exposure to leptin, the overall body is unable to properly make use of all the leptin which the body produces. <br><br>There are factors that contribute to the incidence of leptin resistance. The typical modern-day way of life plays a part in leptin resistance; junk food, hardly any physical activity, way too much stress and insufficient rest. Leptin resistance can also result from a diet full of energy-dense but low-nutrient meals which include highly processed flours, soda, candy or any type of sugar like honey and corn syrup. If an individual becomes leptin resistant, he / she loses the capability to shed extra pounds thus having the inclination to become obese. The truth is insensitivity to leptin and not the actual lack thereof is essentially the reason for the concern with shedding weight.<br><br>How could this concern be resolved? So you can handle the quantity of leptin in the body, weight and food intake ought to be regulated. Seek to boost the body's metabolic rate by way of regular workout so that excess body fat is eliminated.<br><br>Experts are still learning the way to manage leptin resistance by means of diet and exercise to help fight the situation of overweight in the country. It is preferred that you take note of first your individual reasons for starting any kind of diet to help you deal with your specific issue. Many folks are interested in a magic leptin pill yet the best purely natural leptin health supplements are not weight loss or diet capsules. What you will need to do is know how to manufacture significantly more leptin by natural means. Also, you ought to boost your fat burning capacity and manage your appetite to ensure you won't stop [http://www.google.co.uk/search?hl=en&gl=us&tbm=nws&q=shedding+pounds&gs_l=news shedding pounds]. Try to eat more high fiber, low-carb and high-protein food products. If you can have far more organically produced raw foods, that is a lot better.<br><br>Having a few small, healthful meals daily is the true secret to keeping your fat burning capacity rate up and your hunger down. A few folks claim that having a slightly higher calorie meal or two, once per one to two weeks assists to stimulate leptin which might have dropped, on their typical diet program. To further support fat loss, it is recommended that you remove pastured meat, eggs and dairy products from your diet plan and also choose beneficial fats. Consider minimally refined oils (just like coconut and olive oil), nuts, avocadoes and organic fat from animals.<br><br>Body fat cells manufacture leptin that travels to the human brain via the circulatory system. When leptin begins to act upon the brain's appetite control centre, it manages the intake of food of a person. This function of leptin is very essential in managing excess weight and keeping in good health. Hence, as much as possible, leptin resistance should be controlled properly through proper eating plan and also exercising. |
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| In some older documents, and in the name [[Bevatron]], the symbol BeV is used, which stands for billion electron volts; it is equivalent to the GeV.
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| {| class="wikitable" style="float:right; margin:0 0 1em 1em;"
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| ! Measurement !! Unit || SI value of unit
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| | Energy || eV || {{val|1.602176565|(35)|e=-19|u=J}}
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| | Mass || eV/''c''<sup>2</sup> || {{val|1.782662|e=-36|u=kg}}
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| |-
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| | Momentum || eV/''c'' || {{val|5.344286|e=-28|u=kg⋅m/s}}
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| |-
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| | Temperature || eV/''k''<sub>B</sub> || {{val|11604.505|(20)|u=K}}
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| | Time || ''ħ''/eV || {{val|6.582119|e=-16|u=s}}
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| | Distance || ''ħc''/eV || {{val|1.97327|e=-7|u=m}}
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| |}
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| ==Mass==
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| By [[mass–energy equivalence]], the electronvolt is also a unit of mass. It is common in [[particle physics]], where [[mass]] and energy are often interchanged, to express mass in units of eV/''c''<sup>2</sup>, where ''c'' is the [[speed of light]] in vacuum (from [[Mass–energy equivalence|{{nowrap|1=''E'' = ''mc''<sup>2</sup>}}]]). It is common to simply express mass in terms of "eV" as a [[unit of mass]], effectively using a system of [[natural units]] with ''c'' set to 1.{{Citation needed|date=July 2013}}
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| The Mass equivalent of 1 eV is {{val|1.783|e=-36|u=kg}}.
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| For example, an electron and a [[positron]], each with a mass of {{val|0.511|u=MeV/c2}}, can [[annihilate]] to yield {{val|1.022|u=MeV}} of energy. The [[proton]] has a mass of {{val|0.938|u=GeV/c2}}. In general, the masses of all [[hadron]]s are of the order of {{val|1|u=GeV/c2}}, which makes the [[GeV]] (gigaelectronvolt) a convenient unit of mass for [[particle physics]]:
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| :{{val|1|u=GeV/c2}} = {{val|1.783|e=-27|u=kg}}.
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| The [[atomic mass unit]], 1 gram divided by [[Avogadro's number]], is almost the mass of a [[hydrogen atom]], which is mostly the mass of the proton. To convert to megaelectronvolts, use the formula:<ref name=NIST />
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| :1 [[atomic mass unit|amu]] = {{val|931.4941|u=MeV/c2}} = {{val|0.9314941|u=GeV/c2}}.
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| ==Momentum==
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| In [[high-energy physics]], the electron volt is often used as a unit of [[momentum]]. A potential difference of 1 volt causes an electron to gain an amount of energy (i.e., {{val|1|u=eV}}). This gives rise to usage of eV (and keV, MeV, GeV or TeV) as units of momentum, for the energy supplied results in acceleration of the particle.
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| The dimensions of momentum units are {{dimanalysis|length=1|mass=1|time=−1}}. The dimensions of energy units are {{dimanalysis|length=2|mass=1|time=−2}}. Then, dividing the units of energy (such as eV) by a fundamental constant that has units of velocity ({{dimanalysis|length=1|time=−1}}), facilitates the required conversion of using energy units to describe momentum. In the field of high-energy particle physics, the fundamental velocity unit is the speed of light in vacuum ''c''. Thus, dividing energy in eV by the speed of light, one can describe the momentum of an electron in units of eV/''c''.<ref name="FNALunits">{{cite web |url=http://quarknet.fnal.gov/toolkits/ati/whatgevs.html |title=Units in particle physics |publisher=Fermilab |date=22 March 2002 |work=Associate Teacher Institute Toolkit |accessdate=13 February 2011 }}</ref> | |
| <ref name="SLACunits">{{cite web |url=http://www2.slac.stanford.edu/vvc/theory/relativity.html |title=Special Relativity |publisher=SLAC |date=15 June 2009 |work=Virtual Visitor Center |accessdate=13 February 2011 }}</ref>
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| The fundamental velocity constant ''c'' is often ''dropped'' from the units of momentum by way of defining units of length such that the value of ''c'' is unity. For example, if the momentum ''p'' of an electron is said to be {{val|1|u=GeV}}, then the conversion to MKS can be achieved by:
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| :<math>p = 1\; \text{GeV}/c = \frac{(1 \times 10^{9}) \cdot (1.60217646 \times 10^{-19} \; \text{C}) \cdot \text{V}}{(2.99792458 \times 10^{8}\; \text{m}/\text{s})} = 5.344286 \times 10^{-19}\; \text{kg}{\cdot}\text{m}/\text{s}.</math>
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| ==Distance==
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| In [[particle physics]], a system of "natural units" in which the speed of light in vacuum ''c'' and the [[Planck constant|reduced Planck constant]] ''ħ'' are dimensionless and equal to unity is widely used: {{nowrap|1=''c'' = ''ħ'' = 1}}. In these units, both distances and times are expressed in inverse energy units (while energy and mass are expressed in the same units, see [[mass–energy equivalence]]). In particular, particle [[scattering length]]s are often presented in units of inverse particle masses.
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| Outside this system of units, the conversion factors between electronvolt, second, and nanometer are the following:<ref name="NIST"/>
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| :<math>\hbar = {{h}\over{2\pi}} = 1.054\ 571\ 726(47)\times 10^{-34}\ \mbox{J s} = 6.582\ 119\ 28(15)\times 10^{-16}\ \mbox{eV s}.</math>
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| The above relations also allow expressing the [[mean lifetime]] ''τ'' of an unstable particle (in seconds) in terms of its [[decay width]] ''Γ'' (in eV) via {{nowrap|1=''Γ'' = ''ħ''/''τ''}}. For example, the [[B meson|B<sup>0</sup> meson]] has a lifetime of 1.530(9) [[picosecond]]s, mean decay length is {{nowrap|1=''cτ'' = {{val|459.7|u=µm}}}}, or a decay width of {{val|4.302|25|e=-4|u=eV}}.
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| Conversely, the tiny meson mass differences responsible for [[Neutral particle oscillation|meson oscillations]] are often expressed in the more convenient inverse picoseconds.
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| ==Temperature==
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| In certain fields, such as [[plasma physics]], it is convenient to use the electronvolt as a unit of temperature. The conversion to [[kelvin]] is defined by using ''k''<sub>B</sub>, the [[Boltzmann constant]]:
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| :<math>{1 \over k_{\text{B}}} = {1.602\,176\,53(14) \times 10^{-19} \text{ J/eV} \over 1.380\,6505(24) \times 10^{-23} \text{ J/K}} = 11\,604.505(20) \text{ K/eV}.</math>
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| For example, a typical [[magnetic confinement fusion]] plasma is {{val|15|u=keV}}, or 170 megakelvin.
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| As an approximation: ''k''<sub>B</sub>''T'' is about {{val|0.025|u=eV}} (≈ {{sfrac|290 K|11604 K/eV}}) at a temperature of {{val|20|u=degC}}.
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| ==Properties== | |
| [[File:Colors in eV.svg|thumb|upright=2|Energy of photons in the visible spectrum]]
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| [[File:EV to nm vis.png|thumb]]
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| The energy ''E'', frequency ''v'', and wavelength λ of a photon are related by
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| :<math>E=h\nu=\frac{hc}{\lambda}=\frac{(4.135 667 33\times 10^{-15}\,\mbox{eV}\,\mbox{s})(299\,792\,458\,\mbox{m/s})}{\lambda}</math>
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| where ''h'' is the [[Planck constant]], ''c'' is the [[speed of light]]. This reduces to
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| :<math>E\mbox{(eV)}=\frac{1239.84187\,\mbox{eV}\,\mbox{nm}}{\lambda\ \mbox{(nm)}}.</math>
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| A photon with a wavelength of {{val|532|u=nm}} (green light) would have an energy of approximately {{val|2.33|u=eV}}. Similarly, {{val|1|u=eV}} would correspond to an infrared photon of wavelength {{val|1240|u=nm}}, and so on. | |
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| ==Scattering experiments==
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| In a low-energy nuclear scattering experiment, it is conventional to refer to the nuclear recoil energy in units of eVr, keVr, etc. This distinguishes the nuclear recoil energy from the "electron equivalent" recoil energy (eVee, keVee, etc.) measured by [[Scintillation (physics)|scintillation]] light. For example, the yield of a [[phototube]] is measured in phe/keVee ([[photoelectron]]s per keV electron-equivalent energy). The relationship between eV, eVr, and eVee depends on the medium the scattering takes place in, and must be established empirically for each material.
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| ==Energy comparisons==
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| * {{val|5.25|e=32|u=eV}}: total energy released from a 20 [[TNT equivalent|kt]] nuclear fission device
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| * ~624 [[exa-|E]]<nowiki/>eV ({{val|6.24|e=20|u=eV}}): energy consumed by a single 100-watt light bulb in one second ({{val|100|u=W}} = {{val|100|u=J/s}} ≈ {{val|6.24|e=20|u=eV/s}})
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| * 300 [[exa-|E]]<nowiki/>eV ({{val|3|e=20|u=eV}} = ~{{val|50|ul=J}}):<ref>[http://www.desy.de/user/projects/Physics/General/open_questions.html Open Questions in Physics.] German Electron-Synchrotron. A Research Centre of the Helmholtz Association. Updated March 2006 by JCB. Original by John Baez.</ref> the so-called [[Oh-My-God particle]] (the most energetic cosmic ray particle ever observed)
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| * {{val|1|u=PeV}}: one petaelectronvolt, the amount of energy measured in each of two different cosmic neutrino candidates detected by the IceCube neutrino telescope in Antarctica<ref>[http://www.newscientist.com/article/dn23438-icebound-hunter-sees-first-hint-of-cosmic-neutrinos.html Ice-bound hunter sees first hint of cosmic neutrinos] New Scientist. 22:49 24 April 2013. by Anil Ananthaswamy.</ref>
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| * {{val|14|u=TeV}}: the designed proton collision energy at the [[Large Hadron Collider]] (which has operated at half of this energy {{as of|2010|03|30|alt=since 30 March 2010}})
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| * {{val|1|u=TeV}}: a trillion electronvolts, or {{val|1.602|e=-7|u=J}}, about the kinetic energy of a flying [[mosquito]]<ref>[http://public.web.cern.ch/Public/en/Science/Glossary-en.php CERN - Glossary]</ref>
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| * 125.3±0.6 GeV: the energy emitted by the decay of the [[Higgs Boson]], as measured by two separate detectors at the [[Large Hadron Collider|LHC]] to a certainty of [[Standard deviation|5 sigma]]<ref>http://press.web.cern.ch/press/PressReleases/Releases2012/PR17.12E.html</ref>
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| * {{val|210|u=MeV}}: the average energy released in fission of one [[Plutonium-239|Pu-239]] atom
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| * {{val|200|u=MeV}}: the average energy released in [[nuclear fission]] of one [[Uranium-235|U-235]] atom
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| * {{val|17.6|u=MeV}}: the average energy released in the [[Nuclear fusion|fusion]] of [[deuterium]] and [[tritium]] to form [[helium-4|He-4]]; this is {{val|0.41|u=PJ}} per kilogram of product produced
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| * {{val|1|u=MeV}} ({{val|1.602|e=-13|u=J}}): about twice the [[rest energy]] of an electron
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| * {{val|13.6|u=eV}}: the energy required to [[ion]]ize [[hydrogen atom|atomic hydrogen]]; [[Molecular bond|molecular]] [[bond energy|bond energies]] are on the [[orders of magnitude|order]] of {{val|1|u=eV}} to {{val|10|u=eV}} per bond
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| * {{val|1.6|u=eV}} to {{val|3.4|u=eV}}: the [[photon energy]] of visible light
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| * {{val|25|u=meV}}: the [[thermal energy]] ''k''<sub>B</sub>''T'' at room temperature; one air molecule has an [[kinetic theory|average kinetic energy]] {{val|38|u=meV}}
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| * {{val|230|u=µeV}}: the [[thermal energy]] ''k''<sub>B</sub>''T'' of the [[cosmic microwave background]]
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| ==See also==
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| *[[Orders of magnitude (energy)]]
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| == Notes and references ==
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| {{Reflist|2}}
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| ==External links==
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| *[http://www1.bipm.org/en/si/si_brochure/chapter4/table7.html BIPM's definition of the electronvolt]
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| *http://physics.nist.gov/cuu/Constants physical constants reference; CODATA data
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| {{SI units}}
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| {{DEFAULTSORT:Electron Volt}}
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| [[Category:Particle physics]]
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| [[Category:Units of chemical measurement]]
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| [[Category:Units of energy]]
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| {{Link FA|cs}}
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Probably you have previously seen an individual discuss leptin yet failed to fully understand what it is. There are a lot of hormones which help modulate energy balance inside the human body which include appetite, metabolism and hunger. Leptin, a hormone which takes on a vital function in managing energy intake along with energy output, may be one of the most critical hormones in your body which will ascertain your well being and life.
This hormone activates the leptin receptors inside the hypothalamus which is a key process to manage body weight. While leptin is thought to be as a satiety hormone which the fat cells make, it doesn't suggest that those with far more body fat cells have got more leptin which tends to help them eat less and also weigh much less. It basically doesn't work that way.
Data reveal that for individuals with corresponding body mass index, women have got leptin levels which is three to four times greater than men. They are affected not only by body fat but also by simply how much a person feeds on. Leptin levels seem to correspond strongly to the levels of blood sugar.
What are the downfalls of higher leptin levels? You may have thought about leptin hormone. Leptin by nature can easily contribute to body tissue and organ inflammation. The greater the amount of body fat you have, the more leptin you produce. Resistance to leptin is another growing concern. With an excess of nonstop exposure to leptin, the overall body is unable to properly make use of all the leptin which the body produces.
There are factors that contribute to the incidence of leptin resistance. The typical modern-day way of life plays a part in leptin resistance; junk food, hardly any physical activity, way too much stress and insufficient rest. Leptin resistance can also result from a diet full of energy-dense but low-nutrient meals which include highly processed flours, soda, candy or any type of sugar like honey and corn syrup. If an individual becomes leptin resistant, he / she loses the capability to shed extra pounds thus having the inclination to become obese. The truth is insensitivity to leptin and not the actual lack thereof is essentially the reason for the concern with shedding weight.
How could this concern be resolved? So you can handle the quantity of leptin in the body, weight and food intake ought to be regulated. Seek to boost the body's metabolic rate by way of regular workout so that excess body fat is eliminated.
Experts are still learning the way to manage leptin resistance by means of diet and exercise to help fight the situation of overweight in the country. It is preferred that you take note of first your individual reasons for starting any kind of diet to help you deal with your specific issue. Many folks are interested in a magic leptin pill yet the best purely natural leptin health supplements are not weight loss or diet capsules. What you will need to do is know how to manufacture significantly more leptin by natural means. Also, you ought to boost your fat burning capacity and manage your appetite to ensure you won't stop shedding pounds. Try to eat more high fiber, low-carb and high-protein food products. If you can have far more organically produced raw foods, that is a lot better.
Having a few small, healthful meals daily is the true secret to keeping your fat burning capacity rate up and your hunger down. A few folks claim that having a slightly higher calorie meal or two, once per one to two weeks assists to stimulate leptin which might have dropped, on their typical diet program. To further support fat loss, it is recommended that you remove pastured meat, eggs and dairy products from your diet plan and also choose beneficial fats. Consider minimally refined oils (just like coconut and olive oil), nuts, avocadoes and organic fat from animals.
Body fat cells manufacture leptin that travels to the human brain via the circulatory system. When leptin begins to act upon the brain's appetite control centre, it manages the intake of food of a person. This function of leptin is very essential in managing excess weight and keeping in good health. Hence, as much as possible, leptin resistance should be controlled properly through proper eating plan and also exercising.