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	Density - MSN Encarta
		In physics, density is the ratio of the mass of a substance to its volume, and it can be calculated by dividing the mass by the volume.
		Specific gravity is the density of a substance divided by the density of another substance that is used as a standard.
		Charge density is the total electric charge contained in a volume divided by that volume.
	encarta.msn.com /encyclopedia_761567796/Density.html (499 words)

	Ionic and Covalent Binding - Classification of Chemical Bonds
		The density distribution resulting from the overlap of the undistorted atomic densities (the distribution which is subtracted from the molecular distribution) does not place sufficient charge density in the binding region to balance the nuclear forces of repulsion.
		The increase in charge density in the antibinding regions and the removal of charge density from the immediate regions of the nuclei result in an increase in the forces of repulsion exerted on the nuclei, forces resulting from the close approach of the two atoms and from the partial overlap of their density distributions.
		The pattern observed for nitrogen, a charge increase concentrated along the bond axis in both the binding and antibinding regions and a removal of charge density from a region perpendicular to the axis, is characteristic of atoms which in the orbital model of bonding employ p atomic orbitals in forming the bond.
	www.chemistry.mcmaster.ca /esam/Chapter_7/section_1.html (1914 words)

	Charge density - Wikipedia, the free encyclopedia
		The charge density is the amount of electric charge in a volume.
		It should not be confused with the charge carrier density.
		The charge density appears in the continuity equation which follows from Maxwell's Equations in the electromagnetic theory.
	en.wikipedia.org /wiki/Charge_density (299 words)

	Ionic and Covalent Binding - Molecular Charge Distribution of Homonuclear Diatomic Molecules
		For the remaining molecules charge density is increasingly accumulated along the bond axis in both the binding and antibinding regions.
		The charge increase in the binding region, while large in amount (Table 7-2), is very diffuse and the bond density profile shows that relative to the other molecules, the charge increase is not concentrated along the bond axis.
		are reflected in the larger increases in the charge densities along the internuclear axis in the binding region.
	www.chemistry.mcmaster.ca /esam/Chapter_7/section_2.html (1541 words)

	Effective Charge of Glass and Silica in Deionized Solutions
		Therefore the charging state of low specific area surfaces is controlled by the ionic strength and pH of the solution bulk, just as in the general case of high salt concentrations.
		These values characterize the equilibrium of bound and mobile charges in the interfacial region, but are not necessarily accessible experimentally, given the requirement of large surface areas for potentiometric titrations and the interpretive ambiguities inherent to other techniques.
		Using the effective surface charge densities implicitly accounts for overexponential decay of the electrostatic potential near the surfaces that follows from the nonlinearity of the Poisson-Boltzmann equation.
	www.physics.nyu.edu /grierlab/charge5b/node2.html (1248 words)

	Empirical & semi-empirical MO theory - Density (Site not responding. Last check: 2007-10-21)
		For such systems we are also interested in the difference between the electron density for electrons of one spin and the electron density for the electrons of the other spin.
		However, as you will discover elsewhere in these pages, in some cases all charge densities in some hydrocarbons are one, so charge density does not act as a discriminator in predicting substitution.
		The splitting is approximately related to the spin density on the C atom bonded to the specific hydrogen atom.
	www.chem.swin.edu.au /modules/mod3/h_density.html (577 words)

	ChargeDensityWave
		Variations of the electron density (local regions of high or low densities) cost a lot of Coulomb energy, so they are strongly suppressed.
		The charge density wave is an example of a cooperative state in which the ionic lattice and electron gas both develop a distortion to lower the total free energy of the sample.
		Charge density waves seem to be enjoying a comeback.
	www.princeton.edu /~npo/ChargeDensityWave.html (534 words)

	Electronic Charge Density Studies (Site not responding. Last check: 2007-10-21)
		Using coherent elastic Bragg scattering theory of X-rays the Fourier transform of the charge density of the unit cell of a periodic crystal is referred to as the structure factor
		The density in the region near the nucleus is much too large to be visualized properly by the contour program, but it is possible to show the differences of both densities by calculating a map from the differences of both structure factor sets.
		Such multipole models divide the charge density of an atom into inner, core and outer, valence regions, which are both spherically symmetric, and a deformation part, which is mathematically described by real spherical harmonics.
	www-hasylab.desy.de /science/groups/schneider_group/ecds/ecds.html (1067 words)

	9.3.5 Surface Charge Density (Site not responding. Last check: 2007-10-21)
		Figure 9.19: Contour plot of the surface charge density on the circumference of the nanodot in an external field.
		Thus, there are typically five nodes of the finite element mesh across the height of the dot and the values of the surface charge density of all five nodes has been plotted in Fig.
		The surface charge densities for different vortex core displacements, as calculated with the FE model, is given in Fig.
	magnet.atp.tuwien.ac.at /scholz/projects/diss/html/node67.html (651 words)

	Electromagnetics and antennas
		Charge is neither created or destroyed, so if in a region there is a changing charge (with time) then there must be current flow in or out of that region.
		Thus the electric field E due to the charges in the source falls off as 1/(r^2) and can be neglected at large r compared to the electric field contribution -(d/dt)A which falls off as 1/r.
		It is therefore possible to have an "electrically neutral current" wherein the moving charge forming the current does not itself provide a source of charge density rho and therefore of electrostatic scalar potential phi.
	www.ee.surrey.ac.uk /Personal/D.Jefferies/emant.html (2232 words)

	High-Density Charge Clusters and Energy Conversion Results
		Charge clusters are formed by many types of electrical discharges and are evident when a spark impacts a metal surface.
		The kinetic energy of the charge cluster at the point or surface of the emitter is considered to be zero and to increase as the charge cluster approaches the target or anode.
		In the case of producing charge clusters in a conducting aqueous solution, the key is to develop a high potential gradient in the vicinity of an electrode that will participate in such field emission.
	www.padrak.com /ine/FB97_1.html (3616 words)

	XD charge density package
		This leads to a ``ball and stick'' model of the atoms and bonds representing the topology of the charge density at the level of its most salient features, found at the positions of the atomic nuclei.
		The chemical structure of molecules can be extracted from an analysis of the topology of the charge distribution, the features of which are summarized by the curvatures of the charge density at its critical points.
		Laplacian of the charge density in a sulphur-sulphur bond [1].
	www.chem.gla.ac.uk /~paul/xd.html (987 words)

	Thomas-Fermi mixing
		A new charge mixing scheme is tested here, which uses the Thomas-Fermi-von Weizsacker equation to solve the charge density response function to the potential.
		This is a result of the new input potential being the result of a charge density that was found to be a minimum after being allowed to react to its surroundings.
		It is necessarry for the chemical potential m for the DFT and the purely charge density functional to be identical.
	www.nersc.gov /projects/paratec/METHODS/Thomas-Fermi.htm (1227 words)

	Charge Cluster Transmutation
		The charge cluster is then accelerated (through the oxide) toward the surface of the aluminum anode where it drills small micrometer holes into the aluminum.
		2 when the charge cluster approaches a target anode, the electrostatic field is high enough to repel all electrons away from the nuclei of the target anode metal lattice leaving a plasma of fully-ionized metal nuclei that have not had time to avoid the approaching charge cluster.
		The concept is that the charge cluster must be able to persist for some short time period and energetically impact a nucleus in the electrolyte to produce a nuclear reaction.
	www.padrak.com /ine/NEN_5_2_8.html (2877 words)

	Vortex Charge
		The charge resides as a small imbalance between the average density of unpaired carriers within the vortex core compared with the density of the surrounding condensate.
		After the idea of charged vortices was first broached, theorists have proposed a plethora of causes for vortex charging.
		When we look closely at a single charged vortex, we see that it does not actually carry a net charge, but instead is a kind of ‘radial dipole.’ The charge in the core—made up of normal, unpaired quasiparticles—is compensated by an equal amount of superconducting charge just outside the vortex core.
	www.cas.muohio.edu /~clayhoja/VortexCharge.htm (1013 words)

	Bader Analysis
		A zero flux surface is a 2-D surface on which the charge density is a minimum perpendicular to the surface.
		Typically in molecular systems, the charge density reaches a minimum between atoms and this is a natural place to separate atoms from each other.
		The volumes associated with atoms are those for which the maximum in charge density within the volume is closest to the atom.
	theory.cm.utexas.edu /bader (747 words)

	NEMO Calculation Options -- Charge Density (Site not responding. Last check: 2007-10-21)
		The charge density shows the free carrier density in units of Coulombs/nm3.
		A semi-classical approximation estimates charge in the contact regions assuming a constant quasi-Fermi level.
		Charge in the active quantum region may be ignored for approximate calculations.
	www.cfdrc.com /nemo/docs/nemocalccharge.htm (61 words)

	G. Gruner Solid State Physics Group at UCLA
		The former is called the charge density wave (CDW), the latter the spin density wave (SDW) state of metals.
		Charge density waves were first discussed by Frölich in 1954 and by Peierls in 1955; spin density wave states were postulated by Overhauser in 1962.
		In low dimensional metals, where the ground state is a charge density wave or spin density wave condensate, we have found dramatic deviations from the Drude response in the metallic state at temperatures above the phase transitions.
	www.physics.ucla.edu /research/solid-state/research/index.htm (1546 words)

	Dissimilar Surfaces
		Figure 2: The charge density of surfaces with silanol, carboxyl, or sulfate head groups as a function of pH.
		3, where we have plotted the charge density of a glass or silica surface and the electrostatic pressure as it interacts with either its own kind or with a surface of the carboxyl or the sulfate type.
		While all anionic surfaces will reduce the effective charge on silica upon approach, the rate at which they do so strongly depends on the amount and variability of their own charge.
	www.physics.nyu.edu /grierlab/charge5b/node5.html (626 words)

	Jefferson Lab's Hall C first to measure neutron's electric charge density distribution
		An experimental collaboration in Jefferson Lab's Hall C is the first to measure the neutron's electric charge density distribution with unprecedented precision.
		"We needed the density of a liquid to obtain a sufficient number of scattering events to measure the relatively small effect of the neutron charge," explains James J. Kelly of the University of Maryland in College Park and a member of the E93-038 team.
		Then, from the electric form factor the density of the charge within the neutron was deduced.
	www.eurekalert.org /pub_releases/2002-09/djna-jlh090602.php (707 words)

	NREL: Charge Density in C, Si, and Ge (Site not responding. Last check: 2007-10-21)
		This figure indicates that charge is depeleted from interstital and deposited on the bond.
		Figure 3: Comparison of the LAPW calculated static valence charge density of Si with Deutsch's fit to the measured data of Cummings and Hart.
		Note that the bond charge is elongated parallel to the bond direction in diamond while in Si and Ge it is perpendicular to the bond direction.
	www.sst.nrel.gov /research/cdn.html (231 words)

	[No title]
		However, now that they are polarized, some charge centers that were contained in V in their unpolarized state have moved out of the surface S and left behind unneutralized centers of charge.
		To determine the net unneutralized charge left behind in V, we will assume (without loss of generality) that the negative centers of charge are stationary and that only the positive centers of charge are mobile during the polarization process.
		The charge found from this volume integral must be the same as given by the second way of calculating the net charge, by (4).
	web.mit.edu /6.013_book/www/chapter6/6.1.html (858 words)

	Numeric Solution of the Non-Linear Poisson-Boltzmann Equation (Site not responding. Last check: 2007-10-21)
		With a separable density we need only reason in one dimension since the other dimensions will be similar and the final contribution is the product of the contributions of each dimension.
		These results show that the discretization of the partial charge density is not expected to be a large source of errors in such electrostatic calculations.
		A spherical charge density was created centered at the origin with radius 2 by performing a Monte Carlo volume integration with radius 2 and subtracting a Monte Carlo volume integration with radius 1.9 (both used 100 probes and resulted in a relative error of less than 0.5% on the volume).
	www.chemcomp.com /feature/pboltz.htm (2338 words)

	Physics Formulas
		where λ is the linear charge density, σ is the surface charge density, and ρ is the volume charge density
		Acceleration of a charged particle of mass m and charge q in an electric field
		Electric potential at a perpendicular distance a from an infinite, uniformly charged wire with a linear charge density λ
	nas.cl.uh.edu /blanford/FormulasElectromagnetism.htm (609 words)

	Evidence of a charge-density threshold for optimum efficiency of biocidal cationic surfaces -- Kügler et al. 151 ...
		the graft density and the length of the polymer chains.
		on the charged substrate, the outer membrane is destabilized,
		of the charge density of cationic substrates to the induction
	mic.sgmjournals.org /cgi/content/full/151/5/1341 (3602 words)

	Spin density wave - Wikipedia, the free encyclopedia
		Fundamentally SDWs and CDWs involve the development of a periodic modulation in the density of the electronic spins and charges with a characteristic spatial frequency q that does not transform according to the symmetry group that describes the ionic positions.
		If the new periodicity is a rational fraction or multiple of the lattice constant, the density wave is said to be commensurate; other the density wave is termed incommensurate.
		The hysteretic motion of density waves is therefore not unlike that of dislocations or magnetic domains.
	en.wikipedia.org /wiki/Spin_density_wave (652 words)

	5 Current density
		is the charge density in the rest frame of the moving charges, also referred to as proper density.
		is seen in the current density as in the energy-momentum 4-vector and this suggests that there will also be a mathematical process for current density that allows to leave out this factor to reach an invariant result, equivalent to the relativistic Lagrangian for energy-momentum.
		This distinguishes the properties charge and current in the electromagnetic field from the properties mass and energy-momentum in the gravity field and seems to suggests a dimensional hierarchy, i.e.
	www.euclideanrelativity.com /4vectors/node5.html (277 words)

	The current density 4-vector
		That is, the charge carried by a given particle has the same measure in all inertial frames.
		In particular, the charge carried by a particle does not vary with the particle's velocity.
		Clearly, charge density and current density transform as the time-like and space-like components of the same 4-vector.
	farside.ph.utexas.edu /teaching/jk1/lectures/node16.html (278 words)

	Dynamic alterations of glomerular charge density in fixed rat kidneys suggest involvement of endothelial cell coat -- ...
		The charge of the GCW was determined (5) using
		the charge density in response to alterations of I. On the
		Charge of the glomerular filtration barrier in healthy and nephrotic humans.
	ajprenal.physiology.org /cgi/content/full/285/4/F722 (4525 words)

	JCE 1997 (74) 771 [Jul] Teaching Chemistry with Electron Density Models
		Another way to construct an electron density model of lithium is to choose a particular value of the electron density and show all points in space where the density has the chosen value.
		Two isodensity models of lithium are superimposed in Figure 1b: the "solid" model corresponds to a density of 0.02 and the "mesh" model corresponds to a density of 0.002 (a "mesh" was chosen for the outermost model because it is "transparent" and allows us to see the inner model).
		This means that points of low electron density are located farther away from the nucleus than points of high electron density (electron density decreases as we move away from the nucleus).
	jchemed.chem.wisc.edu /Journal/Issues/1997/Jul/abs771.html (4368 words)

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