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Topic: Hydrogen line

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Hydrogen

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	Hydrogen - Wikipedia, the free encyclopedia
		Hydrogen is the most abundant of the chemical elements, constituting roughly 75% of the universe's elemental mass.
		Hydrogen solubility in metals is influenced by local distortions or impurities in the metal crystal lattice.
		Spectroscopy of superheavy hydrogen isotopes in stopped-pion absorption by nuclei.
	en.wikipedia.org /wiki/Hydrogen (4420 words)

	Hydrogen line - Wikipedia, the free encyclopedia
		Because of magnetic interactions between the particles, a hydrogen atom that has the spins of the electron and proton aligned in the same direction (parallel) has slightly more energy than one where the spins of the electron and proton are in opposite directions (anti-parallel).
		The line has an extremely small natural width because of its long lifetime, so most broadening is due to doppler shifts caused by the motion of the emitting regions relative to the observer.
		Hydrogen line observations have also been used indirectly to calculate the mass of galaxies, to put limits on any changes over time of the universal gravitational constant and to study dynamics of individual galaxies.
	en.wikipedia.org /wiki/Hydrogen_line (752 words)

	Liquid Hydrogen Tank
		The liquid hydrogen tank is an aluminum semimonocoque structure of fusion-welded barrel sections, five major ring frames, and forward and aft ellipsoidal domes.
		The liquid hydrogen feed line flow rate is 465 pounds per second with the SSMEs at 104 percent or a maximum flow of 47,365 gallons per minute.
		The liquid hydrogen tank is 331 inches in diameter, 1,160 inches long, and has a volume of 53,518 cubic feet and a dry weight of 29,000 pounds.
	www.spaceonline.tv /lh.htm (154 words)

	Ask An Astronomer > Galactic Astronomy
		The spin-flip transition of atomic hydrogen in its ground electronic state leads to the emission of a photon with a wavelength of 21cm.
		line is considered as probably the most important achievement in the astronomical study of the interstellar medium.
		The higher energy level is due to parallel spins of the proton and electron (equivalent to bar magnets with opposite polarities in a single line) while the lower energy level is due to anti-parallel spins of the proton and electron (equivalent to bar magnets with same polarities on a single line).
	www.iiap.res.in /answers/galactic.html (616 words)

	Hydrogen concentration detection in weld arc plasma - Patent 5093553
		An optical input apparatus (10) for use with a weld evaluation monitor (14) to determine the concentration of hydrogen in a weld arc atmosphere (62) including weld arc plasma and shield gas is disclosed as including an optical fiber bundle (16) having a single optical input (18) and a plurality of optical outputs (22).
		Radiation having only specific wavelengths of hydrogen, shield gas and background emissions are allowed to pass through respective optical line filters (56) to associated optical transducers (58), which generate electrical output signals having amplitudes representative of the intensities of the hydrogen, shield gas and background emissions.
		It was found that the ratio of radiation intensities of the hydrogen Balmer series alpha emission line at 6563 Angstroms and the argon emission line at 6965 Angstroms approximated a linear function of hydrogen concentration in the weld arc plasma.
	www.freepatentsonline.com /5093553.html (4079 words)

	Hydrogen
		Hydrogen molecules do not seem to have been observed in the interstellar medium, but hydrogen atoms are generally taken as indicating the existence of a wide variety of other molecules.
		Hydrogen exists on the Sun, because its absorption lines are observed in the solar spectrum.
		Hydrogen gas is present in small amounts in volcanic gases where it is produced by chemical reactions, but more of it appears combined as hydrogen sulphide and nascent water.
	www.du.edu /~jcalvert/phys/hydrogen.htm (7686 words)

	Hydrotreating process with two phase flow splitting and heat recovery - Patent 5738779
		A recycle hydrogen containing gas in line 22 is enriched with hydrogen from make-up hydrogen compressor C2, via line 24a and passed to inlet line 26 of recycle compressor C1.
		In line 30 the preheated hydrogen containing gas is mixed with preheated hydrocarbon liquid to form a preheated liquid/vapor mixture which is passed to fired furnace E3.
		Hydrogen containing vapor in line 54 is recycled to the process via absorber vessel A, line 60, line 22 and inlet line 26 to recycle compressor C1.
	www.freepatentsonline.com /5738779.html (4128 words)

	Hydrogen Fine Structure
		When the spectral lines of the hydrogen spectrum are examined at very high resolution, they are found to be closely-spaced doublets.
		The small splitting of the spectral line is attributed to an interaction between the electron spin S and the orbital angular momentum L. It is called the spin-orbit interaction.
		The familiar red H-alpha line of hydrogen is a single line according to the Bohr theory.
	hyperphysics.phy-astr.gsu.edu /hbase/quantum/hydfin.html (400 words)

	Why Hydrogen is No Solution (Site not responding. Last check: 2007-10-20)
		Hydrogen's problems are not difficult to understand and require little more than common sense applied to well-documented and easily understandable scientific fact.
		Arguing that hydrogen burned in a car engine produces no greenhouse gases ignores the fact that those same gases were produced at the plant that made the hydrogen to begin with.
		Hydrogen does not freely occur in nature in useful quantities, therefore hydrogen must be split from molecules, either molecules of methane derived from fossil fuels or from water.
	www.fromthewilderness.com /free/ww3/081803_hydrogen_answers.html (2879 words)

	USNO Hydrogen Masers (Site not responding. Last check: 2007-10-20)
		USNO's current hydrogen masers [Symmetricom model MHM 2010] are designed to operate with a maximum frequency instablility of 3.0 parts in 10 to the 15th for periods of from 1,000 to 10,000 seconds and 2.0 parts in 10 to the 13th * t**-(3/5) for 1 sec < t < 1000 sec.
		Some of the main components of a hydrogen maser are the hydrogen gas supply, a controllable "leak" for the gas into the high vacuum system, a gas discharge to produce atomic hydrogen, and a state selector which rejects atoms in the lower energy states and focusses the higher states into the storage bulb.
		The quartz bulb is located in a precisely machined pure copper cylinder which acts as a microwave resonant cavity for the 1.420 GHz frequency of the 21 cm hydrogen line.
	tycho.usno.navy.mil /maser.html (382 words)

	Ask Dr. SETI: What is the Hydrogen Line? (Site not responding. Last check: 2007-10-20)
		The hydrogen line (1420.40575 MHz) is the precession frequency of neutral hydrogen atoms, the most abundant substance in space.
		Hydrogen line radiation was first detected by Harvard grad student Harold Ewen and his professor, Edward Purcell, in 1951.
		It was on the hydrogen line that in 1977 the Big Ear radio telescope at the Ohio State Radio Observatory detected the so-called "Wow!" signal, the most promising, intriguing and beguiling SETI candidate signal to date.
	www.setileague.org /askdr/hydrogen.htm (404 words)

	Hydrogen Control Panel - L&L Special Furnace Co., Inc.
		Hydrogen is used for bright annealing of stainless steel and copper alloys, chemical reductions, brazing and many other processes.
		One line carries the hydrogen, one line the process/purge inert gas and one line the emergency inert purge.
		Hydrogen line has a low flow switch to shut it off if hydrogen flow is not sufficient to maintain positive retort pressure.
	www.hotfurnace.com /pages/furnaces/h2.htm (1318 words)

	Line Spectra of Elements (Site not responding. Last check: 2007-10-20)
		The emission spectra for the hydrogen atom in the visible region is known as the Balmer Series.
		From the equation of the line for the helium graph and these measurements, we will determine the wavelength for each colored hydrogen line.
		The lines produced by these transitions would be a greater or shorter wavelength than we can perceive as visible light, so it could not be part of the spectrum we see.
	www.pitt.edu /~n3lsk/linespecproc.html (1079 words)

	UD Experts & Speakers: Hot Topic
		The presence of a stellar wind is indicated by a subtle absorption signature in the Lyman-alpha line.
		The central part of this line is always dark, because atomic hydrogen in the interstellar gas towards a star absorbs this part of the line.
		This material produces additional absorption in the stellar Lyman-alpha line, and the decrease in velocity of this material means that this additional absorption is Doppler shifted to the "red" side of the interstellar absorption, in agreement with observations.
	www.udel.edu /PR/experts/solarwind.html (1248 words)

	Refinery Reports FAQ
		Hydrogen input from refinery reformer units is counted indirectly as input of crude oil or unfinished oils.
		For example, if special naphtha (line 051) will be used as hydrogen plant feedstock and there will be a return stream of hydrogen feedstock to the refinery, then feedstock shipments to the hydrogen plant, feedstock receipts from the hydrogen plant, and inputs to the refinery must all be reported on line 051.
		Gross inputs reported on line 990 are used for calculating the utilization rate of your atmospheric crude oil distillation unit.
	www.eia.doe.gov /oil_gas/petroleum/survey_forms/faq_refinery.html (3375 words)

	CaFCP Hydrogen Fueling Station
		Hydrogen is delivered to the facility by tanker truck – the same way that gasoline is delivered to a corner gas station.
		The liquid hydrogen line is completely vacuum jacketed to ensure the hydrogen stays cold and to provide an insulation barrier for the refueling operator.
		During fueling, as soon as the hydrogen in the line is cold enough to allow liquid flow, the liquid dispenser delivers hydrogen at a few liquid gallons per minute.
	www.fuelcellpartnership.org /fact_sheets/factsheet_fuelstation.html (930 words)

	Hydrogen Safety, LLC
		Hydrogen Safety is a fully independent, limited liability corporation providing unique solutions to the puzzle of commercializing hydrogen power.
		HS is a leader in hydrogen safety training curricula based on best industry practices, the NASA hydrogen protocol, and emerging codes and standards.
		To respond to the needs of the hydrogen industry for reliable information, HS has evolved the concept of a “Google for Hydrogen” into a unique and comprehensive subscription-based program.
	www.hydrogensafety.com (491 words)

	NIST: Atomic Spectros. - Spectral Line Shapes, etc.
		Observed spectral lines are always broadened, partly due to the finite resolution of the spectrometer and partly due to intrinsic physical causes.
		The principal physical causes of spectral line broadening are Doppler and pressure broadening.
		line at 4861 Å, widely used for plasma diagnostics, is tabulated in the table below for some typical temperatures and electron densities [30].
	physics.nist.gov /Pubs/AtSpec/node20.html (455 words)

	Phys 104 - Hydrogen Spectrum And Energy Levels - Spring 2007
		In this experiment you will use a diffraction grating to measure the wavelength of four visible colored lines emitted by hydrogen, and from those results determine the allowed energy levels of the hydrogen electron.
		When the hydrogen line is centered, write down the angle θ indicated by the pointer (you should estimate to 0.1º).
		To calibrate the spectroscope, carry your spectroscope to the sodium lamp and measure the angle θ for the yellow line.
	it.stlawu.edu /~physics/labs/104_lab/html/h_spect.shtml (297 words)

	Hydrogen energies and spectrum
		The basic hydrogen energy level structure is in agreement with the Bohr model.
		The three prominent hydrogen lines are shown at the right of the image through a 600 lines/mm diffraction grating.
		The measured lines of the Balmer series of hydrogen in the nominal visible region are:
	hyperphysics.phy-astr.gsu.edu /hbase/hyde.html (396 words)

	The 21cm Line of Hydrogen Atoms (Site not responding. Last check: 2007-10-20)
		Hydrogen is the most abundant element in the universe.
		Hydrogen atoms have energy states associated with the ``spins'' of the proton and electron.
		Since the 21cm line has a precisely known wavelength, astronomers can map out the distribution of hydrogen gas in the galaxy and, more importantly, determine its motions.
	www.astro.virginia.edu /class/skrutskie/astr121/notes/21cm.html (106 words)

	How Fast Do Galaxies Move?
		The element hydrogen is the most common element in the universe, and it is plentiful in galaxies.
		Hydrogen is present in huge clouds of gas that fill some of the space between the stars in a galaxy.
		First determine the wavelength of the red hydrogen line, and then compare it to the wavelength of this line in the laboratory sample of hydrogen gas.
	cfa-www.harvard.edu /seuforum/galSpeed (1097 words)

	Clark, Barry Gillespie (1964-04-04) The twenty-one centimeter hydrogen line in absorption. ...
		Clark, Barry Gillespie (1964-04-04) The twenty-one centimeter hydrogen line in absorption.
		In some cases there has been found a variation of the absorption across the face of a source, which, with the kinematical distance to the cloud in question, allowed a typical length to be estimated, which in turn allows estimations of densities and masses.
		This material is briefly analysed statistically, from which it is concluded that the distribution law for central optical depths is approximately [...] and that a line of sight, on the average, intersects 4.1 clouds per kiloparsec in the galactic plane.
	etd.caltech.edu /etd/available/etd-09112002-180017 (233 words)

	Mercury Lamp (Site not responding. Last check: 2007-10-20)
		After using the mercury data to find the line spacing of the grating, you will then examine the spectrum of hydrogen and measure the wavelengths of the visible part of this spectrum.
		In this part of the experiment you will use the grating spacing determined in part 1 and the measured angle of three lines of the hydrogen spectrum to determine the wavelength and energy of the photons associated with these spectral lines.
		After you determine the wavelength of three of the hydrogen emission lines, you will be able to also calculate the frequency of the radiation.
	bama.ua.edu /~stjones/AtomicSpectra.htm (1048 words)

	The Hindu Business Line : Global hydrogen meet to focus on storage aspects
		HYDROGEN has been identified as the best alternative energy carrier by scientists in the pursuit of clean energy sources.
		While there are viable schemes being explored for hydrogen generation, transport of hydrogen is a major issue.
		In addition to transport where hydrogen can fuel IC engines and fuel cells, a wide variety of applications is possible for hydrogen storage systems such as batteries, power augmentation and management, waste heat recovery, freon-free refrigeration, sensors, heat pumps etc.
	www.thehindubusinessline.com /2005/01/29/stories/2005012901971900.htm (347 words)

	APOD: Glossary
		This type of nebula is created when energetic ultraviolet light from a hot star shines on a cloud of hydrogen gas, stripping away electrons from the atoms (ionization).
		A hydrogen atom consists of one proton and one electron.
		Hydrogen composes about 75 percent of the Sun but only a tiny fraction of the Earth.
	antwrp.gsfc.nasa.gov /apod/lib/glossary.html (1562 words)

	[No title]
		The heavier elements were originally made from hydrogen atoms or from other elements that were originally made from hydrogen atoms.
		One of the points where this becomes particularly apparent is the hydrogen line spectrum.
		In the solution to the Schrodinger equation for the hydrogen atom, three quantum numbers arise from the space geometry of the solution and a fourth arises from electron spin.
	www.lycos.com /info/hydrogen--elements.html (324 words)

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