Pd/FER vs Pd/SSZ-13 Passive NOx Adsorbers: Adsorbate-controlled Location of Atomically Dispersed Pd(II) in FER Determines High Activity and Stability

Pd-loaded FER and SSZ-13 zeolites as low-temperature passive NOx adsorbers (PNA) are compared under practically relevant conditions. Vehicle cold-start exposes the material to CO under a range of concentrations, necessitating a systematic exploration of the effect of CO on the performance of isolated Pd ions for PNA. NO release temperature of both adsorbers decreases gradually with the increase of CO concentration from a few hundred to a few thousand ppm. This beneficial effect results from local nano-“hot spots” formation during CO oxidation. Dissimilar to Pd/SSZ-13, increasing the CO concentration above ~1,000 ppm improves the NOx storage significantly for Pd/FER, attributed to the presence of a Pd ions in FER γ-site that is shielded from NOx. CO mobilizes this Pd atom to the NOx accessible position where it becomes active for PNA. This behavior explains the very high resistance of Pd/FER to hydrothermal aging: Pd/FER materials survive hydrothermal aging at 800⁰C in 10% H2O vapor for 16 hours with no deterioration in NOx uptake/release behavior. Thus, by allocating Pd ions to the specific microporous pockets in FER, we have produced very hydrothermally stable and active PNA materials with immediate practical applications.

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Molecule-Based Magnets—An Overview

MRS Bulletin ◽

10.1557/mrs2000.221 ◽

2000 ◽

Vol 25 (11) ◽

pp. 21-30 ◽

Cited By ~ 115

Author(s):

Joel S. Miller ◽

Arthur J. Epstein

Keyword(s):

Low Temperature ◽

Vapor Deposition ◽

Room Temperature ◽

Chemical Vapor ◽

Magnetic Ordering ◽

Low Density ◽

Materials Properties ◽

The Common ◽

New Processing ◽

Very High

Molecule-based magnets are a broad, emerging class of magnetic materials that expand the materials properties typically associated with magnets to include low density, transparency, electrical insulation, and low-temperature fabrication, as well as combine magnetic ordering with other properties such as photoresponsiveness. Essentially all of the common magnetic phenomena associated with conventional transition-metal and rare-earth-based magnets can be found in molecule-based magnets. Although discovered less than two decades ago, magnets with ordering temperatures exceeding room temperature, very high (∼27.0 kOe or 2.16 MA/m) and very low (several Oe or less) coercivities, and substantial remanent and saturation magnetizations have been achieved. In addition, exotic phenomena including photoresponsiveness have been reported. The advent of molecule-based magnets offers new processing opportunities. For example, thin-film magnets can be prepared by means of low-temperature chemical vapor deposition and electrodeposition methods.

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Progress of Research on Welding for Molybdenum Alloys

High Temperature Materials and Processes ◽

10.1515/htmp-2013-0037 ◽

2014 ◽

Vol 33 (3) ◽

pp. 193-200 ◽

Cited By ~ 4

Author(s):

Jiteng Wang ◽

Juan Wang ◽

Yajiang Li ◽

Deshuang Zheng

Keyword(s):

High Temperature ◽

Elevated Temperature ◽

Low Temperature ◽

Welded Joint ◽

Structural Materials ◽

Practical Applications ◽

Traditional Technology ◽

Molybdenum Alloys ◽

Resistance To Oxidation ◽

Temperature Applications

AbstractMolybdenum and molybdenum alloys are considered to be attractive structural materials for high-temperature applications. However, molybdenum alloys are sensitive to gas impurities and have the characteristics of low temperature embrittlement and less resistance to oxidation at elevated temperature. The toughness and strength of welded joint is not easy to be ensured by traditional technology. Recently, many efforts have been made to join molybdenum and its alloys. In this paper, we present the result of investigations on welding methods of molybdenum and its alloys and overview the practical applications in engineering. The key of joining molybdenum alloys is to improve the toughness of welded joint and prevent the generation of pores and cracks.

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Angular dependence ofJcfor YBCO coated conductors at low temperature and very high magnetic fields

Superconductor Science and Technology ◽

10.1088/0953-2048/23/1/014003 ◽

2009 ◽

Vol 23 (1) ◽

pp. 014003 ◽

Cited By ~ 53

Author(s):

A Xu ◽

J J Jaroszynski ◽

F Kametani ◽

Z Chen ◽

D C Larbalestier ◽

...

Keyword(s):

Low Temperature ◽

Magnetic Fields ◽

Angular Dependence ◽

Coated Conductors ◽

High Magnetic Fields ◽

Ybco Coated Conductors ◽

Very High

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Gold in Irish Coal: Palaeo-Concentration from Metalliferous Groundwaters

Minerals ◽

10.3390/min10070635 ◽

2020 ◽

Vol 10 (7) ◽

pp. 635

Author(s):

Liam A. Bullock ◽

John Parnell ◽

Joseph G.T. Armstrong ◽

Magali Perez ◽

Sam Spinks

Keyword(s):

Heat Flow ◽

Low Temperature ◽

Precious Metals ◽

High Heat ◽

Selenium Content ◽

Foreland Basins ◽

High Heat Flow ◽

South Wales ◽

First Time ◽

Very High

Gold grains, up to 40 μm in size and containing variable percentages of admixed platinum, have been identified in coals from the Leinster Coalfield, Castlecomer, SE Ireland, for the first time. Gold mineralisation occurs in sideritic nodules in coals and in association with pyrite and anomalous selenium content. Mineralisation here may have reflected very high heat flow in foreland basins north of the emerging Variscan orogenic front, responsible for gold occurrence in the South Wales Coalfield. At Castlecomer, gold (–platinum) is attributed to precipitation with replacive pyrite and selenium from groundwaters at redox interfaces, such as siderite nodules. Pyrite in the cores of the nodules indicates fluid ingress. The underlying Caledonian basement bedrock is mineralised by gold, and thus likely provided a source for gold. The combination of the gold occurrences in coal in Castlecomer and in South Wales, proximal to the Variscan orogenic front, suggests that these coals along the front could comprise an exploration target for low-temperature concentrations of precious metals.

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A Novel Latching Relay Fabricated Using an Oxide Molded Tungsten Process

MRS Proceedings ◽

10.1557/proc-872-j11.6 ◽

2005 ◽

Vol 872 ◽

Author(s):

J.G. Fleming ◽

Michael Baker ◽

David Luck

Keyword(s):

Chemical Vapor Deposition ◽

Low Temperature ◽

Tensile Stress ◽

Vapor Deposition ◽

Chemical Mechanical Polishing ◽

Chemical Vapor ◽

Metal Contacts ◽

Cmos Compatible ◽

Mems Device ◽

Very High

AbstractIn this paper we describe an oxide molded tungsten process applied to the fabrication of a novel latching relay. The steps in the process are: deposition of a sacrificial oxide, patterning of the oxide, filling of the resulting mold with a blanket film of tungsten using chemical vapor deposition (CVD), and then the removal and planarization of excess tungsten through chemical mechanical polishing (CMP). The process for the incorporation of dielectric isolation has also been developed. The resulting tungsten structures are under high tensile stress, which appears to be compensated in process by the compressive stress of the oxide mold. All the steps are low temperature and the entire process is backend CMOS compatible. This process has been used to fabricate a latching relay which relies on the internal stress of the tungsten and always generates force in a pulling mode. Parts have been successfully fabricated and tested, the devices generate very high forces for a MEMS device and give reasonable contact resistances even without noble metal contacts.

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Hydrogen-atom tunneling through a very high barrier; spontaneous thiol → thione conversion in thiourea isolated in low-temperature Ar, Ne, H2and D2matrices

Physical Chemistry Chemical Physics ◽

10.1039/c8cp01703d ◽

2018 ◽

Vol 20 (20) ◽

pp. 13994-14002 ◽

Cited By ~ 5

Author(s):

Hanna Rostkowska ◽

Leszek Lapinski ◽

Maciej J. Nowak

Keyword(s):

Hydrogen Atom ◽

Low Temperature ◽

Chemical Bond ◽

Very High

Hydrogen-atom tunneling in thiourea involves breaking of the S–H chemical bond and the formation of a new N–H bond.

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Fermi–Dirac Statistics

An Introduction to Statistical Mechanics and Thermodynamics ◽

10.1093/oso/9780198853237.003.0029 ◽

2019 ◽

pp. 386-403

Author(s):

Robert H. Swendsen

Keyword(s):

High Temperature ◽

Low Temperature ◽

Specific Heat ◽

Fermi Energy ◽

Fermi Gas ◽

Main Application ◽

Densities Of States ◽

Low Temperature Specific Heat ◽

Very High ◽

The Ideal

The main application of Fermi–Dirac Statistics is to calculate the properties of electrons. This chapter explains how the properties of fermions account for the behavior of metals. The Fermi energy is introduced and shown to correspond to a very high temperature, so that most properties can be obtained from low-temperature expansions. Both discrete and continuous densities of states are discussed. The Sommerfeld expansion is derived explicitly. The low-temperature specific heat and compressibility are derived. The most important fermions are electrons, and understanding the properties of electrons is central to understanding the properties of all materials. In this chapter we will study the ideal Fermi gas, which turns out to explain many of the properties of electrons in metals.

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Microstructures and High-temperature Strength of Silicide-reinforced Nb Alloys

MRS Proceedings ◽

10.1557/proc-646-n5.39.1 ◽

2000 ◽

Vol 646 ◽

Cited By ~ 2

Author(s):

C.L. Ma ◽

Y. Tan ◽

H. Tanaka ◽

A. Kasama ◽

R. Tanaka ◽

...

Keyword(s):

High Temperature ◽

Quaternary System ◽

Eutectic Reaction ◽

High Temperature Strength ◽

Quaternary Alloys ◽

Two Phase ◽

Practical Applications ◽

Arc Melting ◽

Heat Treated ◽

Very High

ABSTRACTThis article describes the phase stability, microstructures and mechanical properties of silicide-reinforced Nb alloys in Nb-Mo-W-Si quaternary system prepared by arc melting and heat treatment. There exists an equilibrium two-phase field of Nb solid solution (Nbss) and α(Nb,Mo,W)5Si3 in a Nb-rich region of this quaternary system. Alloys in this region have a eutectic reaction of L → Nbss+β(Nb,Mo,W)5Si3 during solidification. The β(Nb,Mo,W)5Si3 transforms to the stable α(Nb,Mo,W)5Si3 at very high temperature. The cast and heat treated hypoeutectic alloys consist of dendritic Nbss, network-shaped Nbss matrix and α(Nb,Mo,W)5Si3. These quaternary alloys exhibit excellent high-temperature strength, although the fracture toughness is still unacceptable for practical applications.

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Scalable Microsprings for Integrated Test and Packaging

ASME 2011 Pacific Rim Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Systems, MEMS and NEMS: Volume 1 ◽

10.1115/ipack2011-52297 ◽

2011 ◽

Author(s):

Eugene M. Chow

Keyword(s):

Thermal Expansion ◽

Low Temperature ◽

Electrical Contacts ◽

Next Generation ◽

Stress Isolation ◽

Lower Height ◽

The Cost ◽

Low K ◽

Known Good Die ◽

Very High

Lithographically defined spring electrical contacts have many applications for next generation electronics test and packaging. The springs can lower the cost of multi-chip modules because their rework ability addresses the known-good-die problem. Lower height chip stacking for mobile electronics markets is enabled because a sliding spring can have a much shorter profile than solder. Larger die can be directly bonded to the board because the compliance absorbs thermal expansion mismatches between substrates. Significant stress isolation is possible, which is important for mechanically sensitive die such as MEMS and low K die. Very high density is possible, as 6 (am pitch has been demonstrated. Fabrication is scalable and assembly is low temperature. This paper reviews our prototype demonstrations for these applications as well as relevant reliability data and contact studies.

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