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gas adsorption

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Series: ASM Handbook
Volume: 7
Publisher: ASM International
Published: 30 September 2015
DOI: 10.31399/asm.hb.v07.a0006107
EISBN: 978-1-62708-175-7
... Abstract This article focuses on the theory, advantages, and limitations of various methods used for the determination of surface area, density, and porosity of powder. These include gas adsorption, permeametry, pycnometry, and mercury porosimetry. Information on various equipment used...
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Published: 01 December 1998
Fig. 5 Effect of particle porosity on (a) green density and (b) green strength of solid and porous iron powders. Powders were pressed at 414 MPa (30 tsi) using die wall lubrication. The figures in parentheses in (a) signify specific surface areas (as measured by the gas adsorption method More
Series: ASM Handbook Archive
Volume: 10
Publisher: ASM International
Published: 01 January 1986
DOI: 10.31399/asm.hb.v10.a0001747
EISBN: 978-1-62708-178-8
... of the material, allowing each to recombine and form a more complex stable compound. The metallic elements will absorb atmospheric gases based on the affinity of the metal for each gas at various temperatures during the melt. Processed materials are again subject to gas adsorption as the material is initially...
Series: ASM Desk Editions
Publisher: ASM International
Published: 01 November 1995
DOI: 10.31399/asm.hb.emde.a0003052
EISBN: 978-1-62708-200-6
... a description of the comminution process (wet and dry milling methods), it discusses batching and mixing operations and granulation methods. The article also deals with the effect of process variables and the steps involved in chemical synthesis, including preparation from solution and gas-phase reactions...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006649
EISBN: 978-1-62708-213-6
... than a coarser powder. To determine the surface area of a powder, a physical adsorption method based on the Brunauer-Emmett-Teller (BET) equation is used, commonly through gas adsorption. The adsorptive gas, such as nitrogen gas, forms a monolayer molecule on all accessible particle surfaces...
Series: ASM Handbook
Volume: 21
Publisher: ASM International
Published: 01 January 2001
DOI: 10.31399/asm.hb.v21.a0003437
EISBN: 978-1-62708-195-5
... Permeability Fisher subsieve sizer 0.2–50 Surface area Gas adsorption (BET) 0.01–20 BET, Brunauer-Emmett-Teller. Source: Ref 4 One method uses a laser to pass a light beam through a suspension of particles. Dispersing the particles in a liquid, such as water, produces a suspension...
Series: ASM Handbook
Volume: 7
Publisher: ASM International
Published: 30 September 2015
DOI: 10.31399/asm.hb.v07.a0006096
EISBN: 978-1-62708-175-7
... subsieve sizer 0.2 ∼ 50 8 × 10 −3 to 2 Surface area Gas adsorption (BET) 0.01 ∼ 20 4 × 10 −4 to 0.08 BET, Brunauer-Emmett-Teller With these different methods, it is important to understand that measurement methods are based on different analytical models (see, for example, the grouping...
Series: ASM Handbook
Volume: 5
Publisher: ASM International
Published: 01 January 1994
DOI: 10.31399/asm.hb.v05.a0001286
EISBN: 978-1-62708-170-2
... (<xref rid="a0001286-ref13" ref-type="bibr">Ref 13</xref>): In sputter deposition and ion plating ( Ref 13 ): Adsorption of inert and/or reactive gaseous species on the surface Gas scattering of vaporized particles Concurrent bombardment by high-energy particles, which can be from reflected high-energy neutrals from the sputtering...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006661
EISBN: 978-1-62708-213-6
... ). Ehrlich ( Ref 4 ) pioneered the so-called flash-desorption method as a means for studying the adsorption of gases such as N 2 , CO, and xenon on polycrystalline surfaces. Ehrlich exposed a clean polycrystalline filament to a flowing gas environment while rapidly flashing the filament at a high rate...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006659
EISBN: 978-1-62708-213-6
... (sample molecule and carrier gas) from the surface of the stationary phase. A quantity can be assigned to this amount of heat and is referred to as the enthalpy of adsorption, Δ H ads . A stationary phase must be selected so that the types of molecules to be separated have different adsorption...
Series: ASM Handbook
Volume: 18
Publisher: ASM International
Published: 31 December 2017
DOI: 10.31399/asm.hb.v18.a0006402
EISBN: 978-1-62708-192-4
... the surface Gas adsorption at surface (+ Auger electron spectroscopy, reflection high-energy electron diffraction) RBS Rutherford backscattering spectroscopy Ion beam Scattered ion Vibration condition &gt;100 µm Analysis of slip products, thin-film density OPM Optical profilometry Light (laser...
Series: ASM Handbook
Volume: 11
Publisher: ASM International
Published: 15 January 2021
DOI: 10.31399/asm.hb.v11.a0006769
EISBN: 978-1-62708-295-2
.... In this case, a sharply pointed tungsten filament is situated near an “extraction” electrode, and the temperature of the electrode is raised to ease electron removal from the tip while simultaneously preventing adsorption of gas molecules. When a high voltage is placed between the extraction electrode...
Series: ASM Handbook
Volume: 7
Publisher: ASM International
Published: 30 September 2015
DOI: 10.31399/asm.hb.v07.a0006065
EISBN: 978-1-62708-175-7
... of the particles. Powders atomized in air show a larger specific surface than inert gas-atomized powders due to the irregular shape. Figure 17 shows specific surface area of aluminum powders measured by the method of gas adsorption (BET). Fine air-atomized powders can have specific surface area values...
Book: Casting
Series: ASM Handbook
Volume: 15
Publisher: ASM International
Published: 01 December 2008
DOI: 10.31399/asm.hb.v15.a0005300
EISBN: 978-1-62708-187-0
... implies, to cover the melt. These fluxes, which are comprised of salt compounds that form a liquid at normal aluminum melting temperatures, provide a molten barrier “blanket” on the surface of the metal to protect it against oxidation and hydrogen gas adsorption. Cover fluxes are mainly a blend of NaCl...
Series: ASM Handbook
Volume: 13A
Publisher: ASM International
Published: 01 January 2003
DOI: 10.31399/asm.hb.v13a.a0003716
EISBN: 978-1-62708-182-5
... metals (Cr, Co) react relatively slowly. From the chemical point of view, the gas- metal reactions represent a broad class of heterogeneous reactions. The composition and structure of the scales produced on metals are a key factor in their behavior in technical applications. Historically, corrosion...
Series: ASM Handbook
Volume: 19
Publisher: ASM International
Published: 01 January 1996
DOI: 10.31399/asm.hb.v19.a0002361
EISBN: 978-1-62708-193-1
... Pressure Mechanism Many of the earlier observations of hydrogen embrittlement were associated with the formation of high-pressure hydrogen gas bubbles in internal voids and microcracks. These hydrogen bubbles may form when the alloy is exposed to a high-hydrogen-fugacity environment such as high...
Book Chapter

Series: ASM Desk Editions
Publisher: ASM International
Published: 01 December 1998
DOI: 10.31399/asm.hb.mhde2.a0003229
EISBN: 978-1-62708-199-3
.... The tracer gas typically used is helium or krypton 85, and detection is by use of a helium mass spectrometer or a nuclear-radiation detector, respectively. Absolute values of the size of the leak sometimes are difficult to determine with back pressuring, because of (a) adsorption and absorption of the tracer...
Series: ASM Desk Editions
Publisher: ASM International
Published: 01 December 1998
DOI: 10.31399/asm.hb.mhde2.a0003169
EISBN: 978-1-62708-199-3
... as well as to bring the material up to drying temperature. Drying is conducted at temperatures close to the boiling point of water, which allows the use of low-quality fuels, such as hot combustion gases from other processes or cheap producer-gas fuel. Also, the low temperature used for the drying process...
Series: ASM Handbook
Volume: 13A
Publisher: ASM International
Published: 01 January 2003
DOI: 10.31399/asm.hb.v13a.a0003698
EISBN: 978-1-62708-182-5
... of the condensed phase. An extraneous gas slows down the vaporization of the condensed phase components (kinetic effect). Part of the vapor, for example, water vapor, dissolves in the condensed phase and modifies the Gibb's free energy of the latter. In 1996, Andreev and Kuznetsov ( Ref 27 ) documented...
Series: ASM Handbook
Volume: 6A
Publisher: ASM International
Published: 31 October 2011
DOI: 10.31399/asm.hb.v06a.a0005551
EISBN: 978-1-62708-174-0
... of welding and brazing in weld brazing, and the combining of riveting and adhesive bonding in rivet bonding. Similar hybrids have also been developed within welding, combining two different welding processes to obtain some benefit(s). A few examples include laser/gas tungsten arc, laser/gas metal arc...