Results 71 to 80 of about 2,750 (239)

Design of the Reactor, Selection of Catalyst for Ortho to Para Hydrogen Conversion and Preliminary Design of Cryogenic System for its Liquefaction [PDF]

Iranian Journal of Chemistry & Chemical Engineering, 2004
Hydrogen is an unusual substance in that its molecule exists in two forms, known as ortho and para, with markedly different properties. Energy level of the ortho molecule is higher than para, therefore, the latter is employed for industrial purposes ...
Naser Saghatoleslami, Javad Sargolzaei, Seyyed Mahmood Mousavi   +2 more
doaj  

Parahydrogen-Induced Hyperpolarization of Unsaturated Phosphoric Acid Derivatives

, 2022
Parahydrogen-induced nuclear polarization offers a significant increase in the sensitivity of NMR spectroscopy to create new probes for medical diagnostics by magnetic resonance imaging.
Alexandra V. Yurkovskaya, Valentin V. Novikov, Alexey S. Kiryutin, Igor A. Nikovskiy, Oleg I. Artyushin, Vitaly P. Kozinenko, Alexander S. Peregudov, Veronika V. Zlobina   +7 more
core   +1 more source

Parahydrogen-enhanced magnetic resonance identification of intermediates in [Fe]-hydrogenase catalysis

Nature Catalysis
Hydrogenases are widespread metalloenzymes used for the activation and production of molecular hydrogen. Understanding the catalytic mechanism of hydrogenases can help to establish industrial (bio)catalytic hydrogen production and conversion.
L. Kaltschnee, Andrey N. Pravdivtsev, Manuel Gehl, Gangfeng Huang, Georgi L. Stoychev, Christoph Riplinger, Maximilian Keitel, Frank Neese, Jan‐Bernd Hövener, Alexander A. Auer, Christian Griesinger, S. Shima, Stefan Glöggler   +12 more
semanticscholar   +1 more source

Facile hyperpolarization chemistry for molecular imaging and metabolic tracking of [1–13C]pyruvate in vivo

Journal of Magnetic Resonance Open, 2023
Hyperpolarization chemistry based on reversible exchange of parahydrogen, also known as Signal Amplification By Reversible Exchange (SABRE), is a particularly simple approach to attain high levels of nuclear spin hyperpolarization, which can enhance NMR ...
Keilian MacCulloch, Austin Browning, David O. Guarin Bedoya, Stephen J. McBride, Mustapha B. Abdulmojeed, Carlos Dedesma, Boyd M. Goodson, Matthew S. Rosen, Eduard Y. Chekmenev, Yi-Fen Yen, Patrick TomHon, Thomas Theis   +11 more
doaj   +1 more source

Parahydrogen-Induced Polarization Study of the Silica-Supported Vanadium Oxo Organometallic Catalyst

, 2018
Parahydrogen can be used in catalytic hydrogenations to achieve substantial enhancement of NMR signals of the reaction products and in some cases of the reaction reagents as well.
Ivan V. Skovpin (1888732), Mostafa Taoufik (1455577), Igor V. Koptyug (1310340), Kai C. Szeto (1475671), Vladimir V. Zhivonitko (1858051)   +4 more
core   +1 more source

Uncertainty analysis of Raman spectra for measuring ortho-parahydrogen compositions

IOP Conference Series: Materials Science and Engineering
Determining ortho-parahydrogen compositions at cryogenic temperatures is an important quality control for liquid hydrogen custody exchange. High orthohydrogen compositions lead to an exothermic reaction resulting in increased boil off and increased ...
K. Appel, J. Leachman
semanticscholar   +1 more source

Essential tools of linear algebra for calculating nuclear spin dynamics of chemically exchanging systems

Journal of Magnetic Resonance Open, 2023
In this work, we describe essential tools of linear algebra necessary for calculating the effect of chemical exchange on spin dynamics and polarization transfer in various nuclear magnetic resonance (NMR) experiments.
Jingyan Xu, Danila A. Barskiy
doaj   +1 more source

Refractive index measurements of solid parahydrogen [PDF]

Optics Letters, 2011
Solid para-H2 is a promising gain medium for stimulated Raman scattering, due to its high number density and narrow Raman linewidth. In preparation for the design of a cw solid hydrogen Raman laser, we have made the first measurements, to our knowledge, of the index of refraction of a solid para-H2 crystal, in the wavelength range of 430-1100 nm. For a
Manori, Perera, Brian A, Tom, Yuki, Miyamoto, Michael W, Porambo, Lauren E, Moore, William R, Evans, Takamasa, Momose, Benjamin J, McCall   +7 more
openaire   +2 more sources

Parahydrogen-Induced Polarization of 1-¹³C‑Acetates and 1-¹³C‑Pyruvates Using Sidearm Hydrogenation of Vinyl, Allyl, and Propargyl Esters

, 2019
13C-hyperpolarized carboxylates, such as pyruvate and acetate, are emerging molecular contrast agents for magnetic resonance imaging (MRI) visualization of various diseases, including cancer. Here, we present a systematic study of 1H and 13C parahydrogen-
Igor V. Koptyug (1310340), Oleg G. Salnikov (1656682), Eduard Y. Chekmenev (1290312), Roman V. Shchepin (1310352), Kirill V. Kovtunov (1310361), Nikita V. Chukanov (3213972), Isaac V. Manzanera Esteve (6693107)   +6 more
core   +1 more source

Nuclear spin hyperpolarization with ansa-aminoboranes : a metal-free perspective for parahydrogen-induced polarization [PDF]

, 2016
The parahydrogen-induced polarization (PHIP) phenomenon, observed when parahydrogen is used in H-2 addition processes, provides a means for substantial NMR signal enhancements and mechanistic studies of chemical reactions. Commonly, noble metal complexes
Repo, Timo, Koptyug, I. (Igor), Kótai, B. (Bianka), Földes, T. (Tamás), Papai, Imre, Koptyug, Igor, Chernichenko, K. (Konstantin), Sorochkina, Kristina, Foldes, Tamas, Repo, T. (Timo), Telkki, Ville-Veikko, Chernichenko, Konstantin, Zhivonitko, V. V. (Vladimir V.), Zhivonitko, Vladimir V., Kotai, Bianka, Telkki, V.-V. (Ville-Veikko), Pápai, I. (Imre), Sorochkina, K. (Kristina)   +17 more
core   +1 more source