Relevant bibliographies by topics / NHC carbene

Academic literature on the topic 'NHC carbene'

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Published: 6 September 2023

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Journal articles on the topic "NHC carbene"

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Mokfi, Moloud, Jörg Rust, Christian W. Lehmann, and Fabian Mohr. "Facile N9-Alkylation of Xanthine Derivatives and Their Use as Precursors for N-Heterocyclic Carbene Complexes." Molecules 26, no. 12 (June 17, 2021): 3705. http://dx.doi.org/10.3390/molecules26123705.

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The xanthine-derivatives 1,3,7-trimethylxanthine, 1,3-dimethyl-7-benzylxanthine and 1,3-dimethyl-7-(4-chlorobenzyl)xanthine are readily ethylated at N9 using the cheap alkylating agents ethyl tosylate or diethyl sulfate. The resulting xanthinium tosylate or ethyl sulfate salts can be converted into the corresponding PF6- and chloride salts. The reaction of these xanthinium salts with silver(I) oxide results in the formation of different silver(I) carbene-complexes. In the presence of ammonia, ammine complexes [Ag(NHC)(NH3)]PF6 are formed, whilst with Et2NH, the bis(carbene) salts [Ag(NHC)2]PF6 were isolated. Using the xanthinium chloride salts neutral silver(I) carbenes [Ag(NHC)Cl] were prepared. These silver complexes were used in a variety of transmetallation reactions to give the corresponding gold(I), ruthenium(II) as well as rhodium(I) and rhodium(III) complexes. The compounds were characterized by various spectroscopic methods as well as X-ray diffraction.
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Jutand, Anny, Julien Pytkowicz, Sylvain Roland, and Pierre Mangeney. "Mechanism of the oxidative addition of aryl halides to bis-carbene palladium(0) complexes." Pure and Applied Chemistry 82, no. 7 (May 4, 2010): 1393–402. http://dx.doi.org/10.1351/pac-con-09-09-22.

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Bis-N-heterocyclic carbenes Pd0 complexes, Pd0(NHC)2, are efficient catalysts in Heck reactions performed with aryl bromides or chlorides. The Pd0(NHC)2 that are not stable are generated in situ from PdII precursors PdY2(NHC)2 (Y = halides) after a chemical reduction. The latter procedure can be mimicked by an electrochemical reduction. The transient Pd0(NHCBn)2 is generated by electrochemical reduction of PdY2(NHCBn)2, and its reactivity in oxidative addition to aryl bromides and chlorides is characterized by the same electrochemical technique with the determination of the rate constants. Pd0(NHCBn)2 is found to be more reactive than the mixed complex Pd0(NHCBn)(PPh3). Both are the reactive species in an associative mechanism. Comparison with the isolated Pd0(NHCtBu)2 reveals that Pd0(NHCBn)2 is more reactive than Pd0(NHCtBu)2 even if the latter reacts via the mono-carbene Pd0(NHCtBu) in a dissociative mechanism. This suggests that the formation of mono-carbene Pd0(NHC) is not a guarantee for a fast oxidative addition because it is always generated at low concentration in its equilibrium with the related nonreactive bis-carbene Pd0(NHC)2.
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Nonnenmacher, Michael, Dominik M. Buck, and Doris Kunz. "Experimental and theoretical investigations on the high-electron donor character of pyrido-annelated N-heterocyclic carbenes." Beilstein Journal of Organic Chemistry 12 (August 23, 2016): 1884–96. http://dx.doi.org/10.3762/bjoc.12.178.

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Rh(CO)2Cl(NHC) complexes of dipyrido-annelated N-heterocyclic carbenes were prepared. From the C–H coupling constant of the respective imidazolium salts and the N–C–N angle of the N-heterocyclic carbene (NHC), a weaker σ-donor character than that of typical unsaturated NHCs is expected. However, the IR stretching frequencies of their Rh(CO)2Cl complexes suggest an electron-donor character even stronger than that of saturated NHCs. We ascribe this to the extremely weak π-acceptor character of the dipyrido-annelated NHCs caused by the conjugated 14 πe− system that thus allows for an enhanced Rh–CO backbonding. This extremely low π-acceptor ability is also corroborated by the 77Se NMR chemical shift of −55.8 ppm for the respective selenourea, the lowest value ever measured for imidazole derived selenoureas. DFT-calculations of the free carbene confirm the low σ-donor character by the fact that the σ-orbital of the carbene is the HOMO−1 that lies 0.58 eV below the HOMO which is located at the π-system. Natural population analysis reveals the lowest occupation of the pπ-orbital for the saturated carbene carbon atom and the highest for the pyrido-annelated carbene. Going from the free carbene to the Rh(CO)2Cl(NHC) complexes, the increase in occupancy of the complete π-system of the carbene ligand upon coordination is lowest for the pyrido-annelated carbene and highest for the saturated carbene.
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Liu, Ming, Jan C. Namyslo, Martin Nieger, Mika Polamo, and Andreas Schmidt. "From betaines to anionic N-heterocyclic carbenes. Borane, gold, rhodium, and nickel complexes starting from an imidazoliumphenolate and its carbene tautomer." Beilstein Journal of Organic Chemistry 12 (December 8, 2016): 2673–81. http://dx.doi.org/10.3762/bjoc.12.264.

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The mesomeric betaine imidazolium-1-ylphenolate forms a borane adduct with tris(pentafluorophenyl)borane by coordination with the phenolate oxygen, whereas its NHC tautomer 1-(2-phenol)imidazol-2-ylidene reacts with (triphenylphosphine)gold(I) chloride to give the cationic NHC complex [Au(NHC)2][Cl] by coordination with the carbene carbon atom. The anionic N-heterocyclic carbene 1-(2-phenolate)imidazol-2-ylidene gives the complexes [K][Au(NHC−)2], [Rh(NHC−)3] and [Ni(NHC−)2], respectively. Results of four single crystal analyses are presented.
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Sun, Hongsui, Xiao-Yan Yu, Paolo Marcazzan, Brian O. Patrick, and Brian R. James. "Rhodium(I)–(N-heterocyclic carbene)–diphosphine complexes." Canadian Journal of Chemistry 87, no. 9 (September 2009): 1248–54. http://dx.doi.org/10.1139/v09-118.

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Reactions of [RhCl(COE)(IPr)]2 (1) and [RhCl(COE)(IMes)]2 (2) (COE = cyclooctene; IPr = N,N′-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene; IMes = N,N′-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene) with the diphosphines Ph2P(CH2)nPPh2 and 1,2-bis(diphenylphosphino)benzene (dppbz) give the N-heterocyclic carbene (NHC) – diphosphine – rhodium(I) complexes: RhCl(NHC)[Ph2P(CH2)nPPh2] [NHC = IPr, n = 1 (3); NHC = IMes, n = 1 (4); NHC = IPr, n = 2 (5); NHC = IMes, n = 2 (6); NHC = IPr, n = 4 (7); NHC = IMes, n = 4 (8)] and RhCl(NHC)(dppbz) [NHC = IPr (9); NHC = IMes (10)]. All the complexes are characterized by 1H, 31P{1H}, and 13C{1H} NMR spectroscopy, elemental analysis, and mass spectrometry. Complexes 3, 7, and 9 are also characterized crystallographically. In benzene solution, the complexes decompose in the presence of O2 with formation of the diphosphine dioxide, whereas reaction with CO leads to replacement of the NHC ligand to give known carbonyl–diphosphine complexes.
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Longevial, Jean-François, Mamadou Lo, Aurélien Lebrun, Danielle Laurencin, Sébastien Clément, and Sébastien Richeter. "Molecular complexes and main-chain organometallic polymers based on Janus bis(carbenes) fused to metalloporphyrins." Dalton Transactions 49, no. 21 (2020): 7005–14. http://dx.doi.org/10.1039/d0dt00594k.

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Janus bis(N-heterocyclic carbenes) composed of a porphyrin core with two N-heterocyclic carbene (NHC) heads fused to opposite pyrroles were used as bridging ligands for the preparation of metal complexes.
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Rupar, Paul A., Michael C. Jennings, and Kim M. Baines. "The reactivity of an anionic gallium N-heterocyclic carbene analogue with a solution stable digermene." Canadian Journal of Chemistry 85, no. 2 (February 1, 2007): 141–47. http://dx.doi.org/10.1139/v07-002.

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The reaction of the anionic gallium(I) N-heterocyclic carbene (NHC) analogue 3 with the solution stable digermene 5 results in the formation of the gallium NHC – germylene complex 8. The gallium NHC – germylene complex 8 was derivatized with CH3I and (CH3)3SiCl.Key words: digermene, carbene analogue, germylene, gallium(I).
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Hock, Andreas, Luis Werner, Christian Luz, and Udo Radius. "N-Heterocyclic carbene and cyclic (alkyl)(amino)carbene adducts of gallium hydrides, gallium chlorides and gallium hydrochlorides." Dalton Transactions 49, no. 32 (2020): 11108–19. http://dx.doi.org/10.1039/d0dt02070b.

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A detailed study on the synthesis and characterization of NHC gallane adducts (NHC)·GaH3, (NHC)·GaH2Cl, and (NHC)·GaHCl2 and the reactivity of these adducts with the cyclic (alkyl)(amino)carbene cAACMe is presented.
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Ojha, Minita, Shweta Choudhary, and Raj K. Bansal. "3-Benzylbenzothiazolylidene Carbene Catalyzed Isomerization of Dimethyl Maleate to Dimethyl Fumarate: Experimental and Theoretical Results." Current Organocatalysis 7, no. 2 (July 2, 2020): 108–17. http://dx.doi.org/10.2174/2213337206666191018111354.

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Background: N-Heterocyclic Carbenes (NHCs) have emerged as ubiquitous species having applications in a broad range of fields, including organocatalysis and organometallic chemistry. Since Arduengo and co-workers first isolated a bottlable NHC, namely imidazol-2-ylidene derivative, these nucleophilic species have attained a prominent place in synthetic organic chemistry. The NHC-induced non-asymmetric catalysis has turned out to be a really fruitful area of research in recent years. Methods and Results: The quantitative aspects of the experimental and theoretical investigation of isomerization of dimethyl maleate to dimethyl fumarate catalyzed by an N-heterocyclic carbene (NHC), namely 3-benzylbenzothiazolylidene are being reported for the first time. Dimethyl maleate on treating with 3-benzylbenzothiazolylidene carbene (10 mol%), generated in situ from the reaction of 3- benzylbenzothiazolium bromide with triethylamine in diethyl ether at room temperature under nitrogen atmosphere isomerizes quantitatively to dimethyl fumarate. Theoretical investigation of a model reaction scheme at the wB97XD/6-31+G(d) level reveals that initial attack of the carbene, which is the ratedetermining step, is followed by rotation about the C-C bond in preference to a higher activation free energy path involving proton abstraction. The species so formed splits off the carbene to yield dimethyl fumarate. Eyring equation has been used to rationalize the effect of temperature on the isomerization rate. Conclusions and Perspective: 3-Benzylbenzothiazolylidene carbene catalyzes the isomerization of dimethyl maleate to its trans-isomer. This carbene can be used in other catalytic reactions, such as acyloin condensation and Stetter reaction.
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Kelemen, Z., R. Streubel, and L. Nyulászi. "Zwitterionic carbene adducts and their carbene isomers." RSC Advances 5, no. 52 (2015): 41795–802. http://dx.doi.org/10.1039/c5ra07039b.

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Dissertations / Theses on the topic "NHC carbene"

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McMullon, Max William. "Exploiting anionically-tethered N-heterocyclic carbene complexes for small molecule activation." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31079.

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N-heterocyclic carbenes (NHCs) can be used as ligands for organometallics complexes, which can then facilitate numerous catalytic applications, such as, C-H activation, small molecule activation and numerous materials applications. The use of anionically-tethered NHCs for usage with electropositive metals has been pioneered by the Arnold group within the last decade. This thesis describes the synthesis of both aryloxide- and amide-tethered NHC organometallic complexes of s-, p-, d- and f-block metals to provide a platform for small molecule activation. Once synthesised, the reactivity of some of these complexes were tested by reaction with CO2 with the aim of turning a molecule considered a harmful (environmentally), waste product into value added products, potentially providing an alternative fuel source. Chapter One introduces the use of anionically-tethered NHCs for use in a number of organometallic complexes as well as their current potential as catalysts for a number of important small molecules. This chapter focuses upon the differences between complexes tethered with anionic O, N, P, S elements, f-element NHC complexes and the use of d-block NHC complexes for catalysis. Chapter Two contains the synthesis and characterisation of a number of aryloxy-tethered NHC p-, d- and f-block organometallic complexes using the ligand H2(LArO R)2. The synthesis of SnII complexes including the synthesis of new ‘normal’ ‘abnormal’ complexes given enough steric bulk around the Sn centre due to the lone pair present in Sn complexes, preventing one of the ligands binding through the classical carbene position and therefore binding through the backbone C4 carbon. The synthesis of MII (Zn, Co and Fe) complexes to compare the solid-state structure and binding mode of the carbenes. The synthesis and characterisation of MIII (Ce and Eu) complexes to assess the solid-state structure and binding modes within f-bock complexes. Chapter Three investigates the reactivity of the MII complexes (Sn, Zn, and Fe) with CO2. Successful reactions were characterised using NMR and further treated with alkynes to target catalytic reactions. Chapter Four contains reactions to target a number of amide-tethered bis (NHC) s-, p-, d- and f-block organometallic complexes using the proligand, H4(LN Mes)Cl3. Deprotonation studies undertaken with a number of bases to give the MI (Li and K) salts and MII (Mg) salts and proved to be unsuccessful upon isolation. Reactions to synthesise the p-, d- and f-block complexes were then undertaken using in situ free carbene production as well as the attempted isolation of the free carbene, both of which also proved unsuccessful. Chapter Five provides an overall conclusion to the work presented in Chapters Two, Three and Four within this thesis. Chapter Six gives the experimental and characterising data for the complexes and reactions.
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Durmus, Semih. "Silver(I) and Gold(I) N-Heterocyclic Carbene Complexes." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1165247084.

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Fauché, Kévin. "NHC portant des azotures : intermédiaires dans la synthèse catalysée d‘hétérocycles polyazotés et auto-fonctionnalisation de complexes métal-NHC." Thesis, Université Clermont Auvergne‎ (2017-2020), 2018. http://www.theses.fr/2018CLFAC062/document.

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Les carbènes N-hétérocycliques (NHC) sont très utilisés pour complexer les métaux de transition. Ils quittent rarement ce rôle de ligand ancillaire et trouvent, depuis une vingtaine d’années, des applications en catalyse ou, plus récemment, en chimie médicinale. Dans ce travail, nous discuterons d’une méthode de synthèse douce conduisant à la formation de complexes AgI – NHC via une source d’argent soluble. Cette méthode nous a permis d’obtenir des complexes bien connus mais également d’accéder à une nouvelle série de complexes NHC-Ag-phosphine. Nous présenterons également une nouvelle réaction où des NHC portant une fonction azoture à proximité du carbone du carbène quittent leur rôle de ligand ancillaire et conduisent à la formation d’hétérocycles azotés par cyclisation carbène-nitrène. Cette réaction sera présentée en détail, ainsi que la caractérisation spectroscopique concernant une sous-série de composés fluorescents obtenus par cette méthode. Enfin, nous présenterons une stratégie de post-fonctionnalisation de complexes développée dans notre équipe. Des complexes argent(I)-NHC portant un azoture proches du centre carbénique catalysent leur propre fonctionnalisation. De plus, des complexes de cuivre(I) portant des azotures en position éloignée du centre métallique seront greffés sur des nanoparticules magnétiques pour servir de catalyseur recyclables
N-heterocyclic carbenes (NHC) are widely used to complex transition metals. They rarely leave their role as ancillary ligand and find, since 20 years, applications in catalysis or, more recently, in medicinal chemistry. In this work, we will discuss a mild synthetic method leading to the formation of AgI – NHC complexes via a soluble silver species. This method allowed us to obtain well known complexes but also to access a new series of NHC-Ag-phosphine complexes. We will also present a new reaction where NHC ligands bearing an azide function close to the carbenic center leave their role as ancillary ligand and lead to the formation of nitrogen rich heterocycles by a carbene-nitrene cyclization. This reaction will be presented in detail, along with the spectroscopic characterization regarding a sub-series of fluorescent compounds obtained by this method. Finally, we will present a post-functionalization strategy of complexes developed in our team. Silver(I)-NHC complexes tagged by an azide close to the carbenic center catalysed their own functionalization. Moreover, copper(I) complexes tagged by an azide function in a distant position from the metallic centre will be grafted on magnetic nanoparticles to act as recyclable catalysts
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Paradiso, Veronica. "Ruthenium metathesis precatalysts with unsymmetrical Nheterocyclic carbene (NHC) ligands." Doctoral thesis, Universita degli studi di Salerno, 2018. http://hdl.handle.net/10556/3017.

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2016 - 2017
Olefin metathesis is one of the most important chemical transformations for the formation of carbon-carbon double bonds. The possibility to build up highly funtionalised alkenes starting from simple olefins makes this reaction indispensable in modern organic synthesis, giving access to a wide range of molecules that would be barely obtained through other synthetic routes. The success of metathesis is due to the development of new and efficient catalysts which can be used in a wide variety of research fields, both in industry and in academia. In this context, the research of the ‘perfect’ metathesis complex still impassions scientists all over the word, and several research papers regarding the development of new catalytic systems are published every year. The group I am part of focuses its attention on the development of new ruthenium metathesis catalysts. Our interest lies in the influence that nature and configuration of substituents on the N-heterocyclic carbene (NHC) ligand could have on the performances of the corresponding metal complexes. In this doctoral thesis, the field of unsymmetrical N-heterocyclic carbene (u-NHC) ruthenium catalysts will be explored. Synthesis and characterisation of several novel complexes will be discussed. Catalytic performances will be evaluated in model metathesis reactions as well as in more attractive metathesis transformations. The relationship between NHC structure and complexes’ behaviours will be investigated using NMR, X-Ray, IR, cyclic voltammetry and DFT calculations. ..[edited by Author]
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Saker, Oliver John. "Mono- and tri-nuclear ruthenium complexes incorporating N-heterocyclic carbene ligands." Thesis, University of Bath, 2008. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.512305.

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Ellul, Charles. "Trimetallic N-heterocyclic carbene complexes." Thesis, University of Bath, 2011. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538279.

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Kelly, Roy A. III. "New Metal-NHC Complexes: Synthesis, Characterization, and Uses." ScholarWorks@UNO, 2014. http://scholarworks.uno.edu/td/1817.

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N-Heterocyclic Carbenes (NHC) present a viable alternative to traditional phosphine ligands in a variety of organometallic mediated catalytic reactions. Singlet ground-state carbenes are stabilized by the push-pull presence of two adjacent nitrogen atoms in an imidizolium 5-membered ring, allowing neutral electron donor properties. The ability to synthesize a variety of NHC ligands with differing steric and electronic properties is possible by changing the sustiuents on the nitrogen atoms of the imidizolium. Tunable characteristics and enhanced chemical and thermal stability give NHC’s an advantage over phosphines in many catalytic systems. This dissertation focuses on the use N-Hetercyclic Carbenes in a variety of organometallic complexes. The synthesis of NHC complexes with a variety of transition metals is described. The transition metals complexed with NHC’s include palladium, iridium, nickel and ruthenium. The catalytic activity of the metal-NHC complexes is investigated as well.
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Li, Kai, and 李凯. "Photoluminescent organoplatinum (II) complexes containing N-heterocyclic carbene (NHC) ligands." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B50533915.

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The syntheses, structures, photophysical properties and applications of three types of photoluminescent organoplatinum(II) complexes containing N-heterocyclic carbene (NHC) ligands are described. The tetradentate dianionic bis(phenolate-NHC) type ligands provide a superior scaffold for constructing thermally stable and efficient deep-blue phosphorescent Pt(II) complexes with λmax of ~440-460 nm and solid-state emission quantum yields of ~30%. Highly efficient blue OLEDs with CIEx, y of (0.19, 0.21) were fabricated based on these emitters with maximum brightness, peak current efficiency and power efficiency of ~9500 cd m^(-2), 24 cd A^(-1) and 17 lm W^(-1), respectively. Structural modification by extending the π-conjugation of the tetradentate bis(phenolate-NHC) ligand leads to strongly phosphorescent platinum(II) complexes with long-lived emissive electronic states that can be used as a luminescent sensor for oxygen. DFT/TDDFT calculations and time-resolved spectroscopic characterizations were performed to gain insight into the structure-photophysics correlation. The N-heterocyclic carbene (NHC) ligand was incorporated into Pt(II) complexes containing tridentate deprotonated 1,3-bis(2-pyridyl)benzene (N^C^N) type ligand. In addition to the [(N^C^N)Pt(NHC)]PF6 type complexes with (N^C^N) in η3-tridentate coordination mode, Pt(II) complexes with η2-bidentate (N^CN) ligands, namely [(N^CN)Pt(NHC)2]PF6, have been isolated and structurally characterized. The highly phosphorescent [(N^C^N)Pt(NHC)]PF6 complexes were used for solution-processed green OLEDs fabrication. The peak current efficiency of 12.5 cd A^(-1) and maximum brightness higher than 2000 cd m^(-2) were achieved. The presence of the pendent pyridyl motif causes quenching of emission of the [(N^CN)Pt(NHC)2]PF6 complexes in solution at room temperature. Turning on solid-state emission of [(N^CN)Pt(nBu2Im)2]PF6 in the presence of an acidic vapor revealed its potential as a luminescent chemosensor. A class of dicationic platinum(II) terpyridyl complexes containing NHC ligand, namely [Pt(tpy)(NHC)](PF6)2, has been synthesized and structurally characterized. Even in the presence of the strong σ-donating NHC ligand, these complexes are non- or weakly emissive in solution at room temperature. However, this class of complexes displays intense emissions in solid state (298 K and 77 K), in glassy solution (77 K butyronitrile) and in PMMA (2 wt.%, 298 K). The ligand (terpyridine) displacement reaction arising from CN attack onto the Pt(II) center has been observed for [Pt(tpy)(nBu2Im)](PF6)2 leading to its application as a chemodosimeter for selective cyanide sensing in aqueous solution.
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Chemistry
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Doctor of Philosophy
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Baffert, Mathieu. "Synthesis of ruthenium complexes having one or more N-heterocyclic carbene ligands supported on hybrid mesostructured silicas and their use in the hydrogenation of carbon dioxide." Phd thesis, Université Claude Bernard - Lyon I, 2011. http://tel.archives-ouvertes.fr/tel-00838661.

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The goal of this PhD was to elaborate supported Ru-NHC catalytic materials based on hybrid organic-inorganic materials having imidazolium units perfectly distributed within a silica matrix. Passivation of these imidazolium materials followed by formation of NHC-carbene and reaction with [RuCl2(p-cymene)]2 provided these well-defined surface sites of general structures RuCl2(NHC)(L), where L was para-cymene (p-cymene) or THF depending on the reaction conditions, which could be further replaced by PMe3. These systems were then tested in the hydrogenation of CO2 in presence of amine to give formamides. The mono-NHC systems were highly active only in the presence of PMe3 ligands, but suffered from Ru leaching, evidencing the low stability of the NHC-Ru bond under the reaction conditions. On the other hand, dinuclear bis-NHC Ru systems were also developed, and they displayed much improved activity and stability in the hydrogenation of CO2 in the presence of PMe3 compared to the mono-NHC systems. This allowed the use of much higher reaction temperatures (200 °C) and provided heterogeneous catalysts with performances close to those obtained with the best homogeneous catalysts, Cl2Ru(dppe)2.
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Marr, Isobel Helen. "Synthesis and reactivity of scandium N-heterocyclic carbene complexes." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/17970.

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Chapter one introduces N-heterocyclic carbenes (NHCs) and discusses their use as ligands for rare earth metal complexes, with particular emphasis upon compounds synthesised from 2009 until the present day. Chapter two details the synthesis and characterisation of the homoleptic scandium-NHC complex [Sc(L)3] (L = [OCMe2CH2(1-C{NCHCHNiPr})]). Reactions of [Sc(L)3] with boranes, CO2 and CS2 are described which exploit the relative lability of the Sc–Ccarbene bond and allow formation of [Sc(L)2(OCMe2CH2(1-B'C{NCHCHNiPr}))] (B' = 9-BBN, BPh3, B(C6F5)3, BH3), [Sc(OCMe2CH2(1-O2CC{NCHCHNiPr})3]n, [Sc(L)2(OCMe2CH2 (1-S2CC{NCHCHNiPr})] and [Sc(L)(OCMe2CH2(1-S2CC{NCHCHNiPr})2]2. The chapter also discusses the reactivity of [Sc(L)3] towards substrates containing acidic C–H and N–H bonds and substrates containing polar E–X bonds (where E = C, Si, B, P and X = Cl, I). Chapter three describes the synthesis and characterisation of the NHC substituted scandium benzyl complexes [Sc(Bn)2(L)]2 and [Sc(Bn)(L)2], and the attempted synthesis of NHC substituted scandium aminobenzyl complexes. The reactivity of [Sc(Bn)2(L)]2 with RX substrates (R = alkyl) is discussed in detail; depending on the nature of the alkyl group, these reactions can allow formation of R–Bn , the result of carbon-carbon coupling. The complex [Sc(Bn)(L)Cl]2 has been isolated from these reactions and is structurally characterised. The reactivity of [Sc(Bn)2(L)]2 towards C–H bonds is explored and attempts to prepare NHC substituted scandium hydrides are described. Comparisons of the relative stability and reactivity of [Sc(Bn)2(L)]2 and [Sc(Bn)3(thf)3] are drawn. Chapter four documents the synthesis and characterisation of [Sc(Odtbp)2(L)] (Odtbp = 2,6-di-tert-butylphenoxide), [Sc(Odtbp)(L)2], and the samarium analogue [Sm(Odtbp)(L)2]. The reactivity of these complexes towards various small molecules is described. The chapter also details attempts to prepare the cationic scandium complexes [Sc(L)2][Bort] (Bort = bis[3,3',5,5'-tetra-(tert-butyl)-2,2-diphenolato]borate) and [Sc(L)2][B(Ph)4]. Chapter five provides overall conclusions to the work presented in this thesis. Chapter six contains all experimental and characterising data for the complexes and reactions detailed in this work.
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Books on the topic "NHC carbene"

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Estates, NHS, ed. Carbon/energy management in healthcare: Best practice advice for the NHS in England on meeting the mandatory carbon/energy targets, March 2000-March 2010. London: Stationery Office, 2004.

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United States. National Aeronautics and Space Administration., ed. Analysis of minerals containing dissolved taraces of the fluid phase components "water" and "carbon dioxide": Final report submitted to the NASA Ames Research Center for NASA cooperative agreement NCC 2-446. Mountain View, CA: SETI Institute, 1991.

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Jaramillo, Marcela, and Valentina Saavedra. NDC Invest: Supporting Transformational Climate Policy and Finance. Inter-American Development Bank, 2021. http://dx.doi.org/10.18235/0003340.

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The Inter-governmental Panel on Climate Change (IPCC) indicates that meeting the Paris Agreement's goal of limiting the global temperature rise from pre-industrial levels to between 1.5 and 2 degrees Celsius requires reaching net-zero emissions of carbon dioxide (CO2) between 2050 and 2070, as well as deep reductions in the emissions of other greenhouse gases by around mid-century (GHGs) (IPCC, 2018). At the same time countries need to build resilience to face the changes that cannot be avoided. NDC Invest was created as the one-stop-shop of the IDB Group providing technical and financial support for countries in Latin American and Caribbean (LAC) in their efforts to achieve the climate objectives under the Paris Agreement, seeking to transition to a net zero, resilient and sustainable development pathways that improve quality of life and prosperity in LAC. Through our research and experience supporting countries and piloting solutions we have developed a toolbox for support. This paper describes three NDC Invest products to support Governments to tackle challenges and scale up action towards a climate aligned and sustainable development path: i) the design of Long-Term Strategies (LTS) for net-zero emissions and resilience; ii) design of ambitious Nationally Determined Contributions (NDCs), aligned to LTS; and iii) design of investment plans and finance strategies. Our three products are not a fix recipe, but rather a toolbox to provide flexible and relevant solutions tailored to country needs and context, and different stages of design and implementation of their climate targets.
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Great Britain: Department of Health: Estates and Facilities Division. Statistics on energy performance and carbon and CO2 Emissions: NHS England, 1999/00 to 2004/05. Stationery Office, The, 2006.

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Strand, Jon. Climate Finance, Carbon Market Mechanisms and Finance “Blending” as Instruments to Support NDC Achievement under the Paris Agreement. World Bank, Washington, DC, 2019. http://dx.doi.org/10.1596/1813-9450-8914.

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Eland, John H. D., and Raimund Feifel. Molecules with four, five or seven atoms. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198788980.003.0005.

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Double photoionisation spectra of NH3, C2H2, HCHO, C2N2, PCl3, CH4, the methyl halides CH3F, CH3Cl, CH3I, the methylene halides CH2Cl2, CH2Br2, CH2I2, the carbon tetrahalides CF4, CCl4, CBr4, germanium tetrahalides GeCl4, GeBr4, and SF6 are presented with analysis to identify the electronic states of the doubly charged ions. The effects of indirect double ionisation pathways are discussed. There are relatively few important molecules with just four atoms, but most of the ones included here are present and sometimes abundant in planetary and astrophysical environments. The range of five-atom molecules includes methane and all its simple derivatives. Where possible closely related molecules are grouped together in this chapter, as much of the discussion of their electronic structure is the same for all members of a group. This chapter also includes SF6 as a closely related molecule, even though its atom count goes beyond those of some molecules in later chapters.
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Marques, Marcia, ed. Estudos Avançados em Engenharia Civil. Bookerfield Editora, 2022. http://dx.doi.org/10.53268/bkf21111100.

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No Brasil a Engenharia Civil se utiliza de ciência aplicada na execução de ações indispensáveis prestadas à sociedade. Além da grande área das Engenharias, sua abrangência multidisciplinar frequentemente colabora com as demais áreas do conhecimento com soluções em benefício da sociedade. Este livro reúne capítulos que trazem importantes avanços relacionados a estruturas, construção civil, eletrotécnica, hidráulica ambiental e geotecnia. Visando uma melhor organização, os capítulos estão agrupados nas seções: Ciência Onshore e Ciência Offshore. A seção de Ciência Onshore é composta por cinco capítulos. Pelo primeiro capítulo é avaliada a resistência e a rigidez de diafragmas horizontais, construídos em Sistemas Leves de Madeira. Foram ensaiados protótipos em escala real com diferentes arranjos construtivos concluindo-se que o emprego de dispositivos enrijecedores permite o aumento da resistência e rigidez dos diafragmas. O segundo capítulo aborda construções em madeira sob a ótica de sistemas com estruturas leves, apresentando análise computacional através de modelagem pelo método de elementos finitos. As análises demonstraram que a flecha real e a calculada para as vigas individuais, que compõem o diafragma de piso, apresentam reduções que variam de 18 a 30% quando comparadas com valores calculados para vigas isoladas. No contexto dos sistemas construtivo e estrutural da Construção Civil, observa-se uma inevitável e progressiva tendência de substituição dos sistemas convencionais por sistemas industrializados. Por meio do terceiro capítulo é apresentada uma revisão bibliográfica sobre conceitos de construção industrializada, abordando o atual cenário técnico no Brasil, e confrontando algumas das principais tecnologias industrializadas presentes hoje no segmento da Construção Civil. O quarto capítulo trata da engenharia aplicada ao ambiente offshore e apresenta uma análise de fadiga estrutural de conexões entre um reforçador longitudinal do costado e uma antepara transversal de uma unidade flutuante de produção, armazenamento e transferência (FPSO) convertida a partir de um navio petroleiro, sendo possível estimar a vida remanescente do FPSO. Por meio do capítulo cinco são apresentados detalhes de um reforço estrutural utilizando polímero reforçado com fibra de carbono (PRFC) em uma plataforma offshore de concreto armado. Apesar de adotada uma técnica consolidada, pouco se sabe sobre o desempenho do reforço ao longo do tempo quando exposto ao ambiente marinho. Pelo capítulo é apresentado um panorama geral da estrutura após 17 anos da execução do reforço que comprovou o bom desempenho da técnica empregada. A seção de Ciência Offshore é composta por quatro capítulos. Pelo capítulo seis é abordada a utilização de sistemas solares fotovoltaicos conectados à rede (SFVCR), enquanto apresenta uma proposta de metodologia para avaliar o potencial fotovoltaico para a Região Metropolitana de Curitiba. Foi realizado ainda, um levantamento do montante de gases de efeito estufa que são deixados de emitir. O capítulo contribui para a implantação de políticas públicas de incentivo para esta fonte energética. Geopolímeros são materiais alternativos ao cimento Portland, apresentando alta resistência mecânica e durabilidade química e térmica. Pelo capítulo sete são avaliadas as propriedades mecânicas de argamassas geopoliméricas contendo adição de Nanotubos de Carbono (NTC) assim como o método de incorporação do nanocompósito a argamassa. Os resultados mostram que os NTC quando bem distribuídos na matriz promovem um aumento de resistência à compressão e flexão das amostras. O capítulo oito trata do fetch, importante elemento na quantificação de fenômenos gerados pelo vento em reservatórios de Usinas Hidrelétricas. A abordagem apresentada amplia a compreensão do fetch através de um conceito bidimensional via processamento computacional, permitindo a geração de mapas e a determinação segura dos valores máximos para cada direção e a localização dos maiores comprimentos para o reservatório de Tucuruí, este importante reservatório no Brasil. Na quantificação dos fenômenos hidrodinâmicos em lagos e reservatórios é frequente a necessidade de conhecer o alcance das perturbações alcançadas pelas ondas ao se propagarem. Este fenômeno está relacionado à ressuspensão de sedimentos, desestratificação térmica, e erosão das margens, afetando o ecossistema aquático, as cadeias produtivas aquícolas e a vida útil de componentes mecânicos das UHE’s. Por meio do capítulo nono é apresentado o conceito de profundidade de mistura aplicado ao reservatório da hidrelétrica de Lajeado, Tocantins. É realizado o mapeamento das profundidades máximas perturbadas pelas ondas de vento ao se propagarem, contribuindo para uma melhor compreensão da estratificação térmica e da ressuspensão de sedimentos no reservatório desta importante usina hidrelétrica.
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Book chapters on the topic "NHC carbene"

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Nagao, Kazunori, and Hirohisa Ohmiya. "N‑Heterocyclic Carbene (NHC)/Metal Cooperative Catalysis." In Asymmetric Organocatalysis Combined with Metal Catalysis, 83–97. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-43851-7_4.

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Nair, Vijay, Rajeev S. Menon, and Jagadeesh Krishnan. "N-Heterocyclic Carbene (NHC)-Mediated Generation and Reactions of Homoenolates." In N-Heterocyclic Carbenes in Organocatalysis, 95–132. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2019. http://dx.doi.org/10.1002/9783527809042.ch4.

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Hahn, F. Ekkehardt. "Complexes with Protic N-Heterocyclic Carbene (NR,NH-NHC) Ligands." In Advances in Organometallic Chemistry and Catalysis, 111–32. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118742952.ch9.

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Muramatsu, Yuki, and Akinori Takasu. "Synthesis of Cyclic Vinyl Polymers via N-Heterocyclic Carbene (NHC)-Initiated Anionic Polymerization and Subsequent Ring-Closure Without Highly Dilute Conditions." In Topological Polymer Chemistry, 277–92. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-6807-4_17.

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Louie, Janis. "Ni-NHC Mediated Catalysis." In N-Heterocyclic Carbenes in Synthesis, 163–82. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2006. http://dx.doi.org/10.1002/9783527609451.ch7.

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Lazreg, Faïma, and Catherine S. J. Cazin. "NHC-Copper Complexes and their Applications." In N-Heterocyclic Carbenes, 199–242. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2014. http://dx.doi.org/10.1002/9783527671229.ch08.

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Chauhan, Pankaj, Suruchi Mahajan, Xiang-Yu Chen, and Dieter Enders. "Domino Processes in NHC Catalysis." In N-Heterocyclic Carbenes in Organocatalysis, 133–56. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2019. http://dx.doi.org/10.1002/9783527809042.ch5.

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Jin, Zhichao, Xingkuan Chen, and Yonggui R. Chi. "Recent Activation Modes in NHC Organocatalysis." In N-Heterocyclic Carbenes in Organocatalysis, 187–212. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2019. http://dx.doi.org/10.1002/9783527809042.ch7.

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Lazreg, Faïma, and Catherine S. J. Cazin. "Medical Applications of NHC-Gold and -Copper Complexes." In N-Heterocyclic Carbenes, 173–98. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2014. http://dx.doi.org/10.1002/9783527671229.ch07.

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Wurm, Thomas, Abdullah Mohamed Asiri, and A. Stephen K. Hashmi. "NHC-Au(I) Complexes: Synthesis, Activation, and Application." In N-Heterocyclic Carbenes, 243–70. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2014. http://dx.doi.org/10.1002/9783527671229.ch09.

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Conference papers on the topic "NHC carbene"

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Flores Vivian, Ismael, Joshua Hoheneder, Lourdes Vergara Alvarez, and Konstantin Sobolev. "Desempeño de compuestos con fibras de alcohol polivinílico y nano-fibras/tubos de carbono." In HAC2018 - V Congreso Iberoamericano de Hormigón Autocompactable y Hormigones Especiales. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/hac2018.2018.6473.

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La adición de fibras en compuestos a base de cemento portland es una práctica común para la prevención de la formación de grietas y para incrementan la resistencia a la flexión. En esta investigación, se estudiaran los compuestos fibro-reforzados (CFR) con fibras de polivinilo alcohol (PVA), reforzadas con nanofibras de carbono (NFC) o nanotubos de carbono (NTC). Los especímenes fabricados fueron ensayados a la resistencia a la flexión y a la conductividad eléctrica en agua o en solución con NaCl. Los resultados demostraron una dependencia de los especímenes al tipo de solución a la cual fueron expuestos. Se demostró que la sensitivdad a la deformación y a la solución de NaCl puede ser incrementada por la adición de los NTC. Los resultados en el incremento de la conductividad con los compuestos de NTC pueden ser escalables para las aplicaciones de monitoreo no-destructivo en estructuras de concreto que requieran una mejora integral bajo las cargas aplicadas y estabilidad en ambientes deletéreos.DOI: http://dx.doi.org/10.4995/HAC2018.2018.6473
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Isa, Siti S. Mat, Muhammad M. Ramli, M. F. Jamlos, N. A. M. Ahmad Hambali, M. Mohamad Isa, S. R. Kasjoo, N. Ahmad, N. I. M. Nor, and N. Khalid. "Multi-walled carbon nanotubes plastic NH3 gas sensor." In 11TH ASIAN CONFERENCE ON CHEMICAL SENSORS: (ACCS2015). Author(s), 2017. http://dx.doi.org/10.1063/1.4975263.

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Faudzi, Najwa Mohd, Ahmad Rashidy Razali, Asrulnizam Abd Manaf, Nurul Huda Abd Rahman, Ahmad Azlan Aziz, Amiruddin Ibrahim, and Aiza Mahyuni Mozi. "Characterization of Carbon-based NFC Tag Antenna Design." In 2022 IEEE International RF and Microwave Conference (RFM). IEEE, 2022. http://dx.doi.org/10.1109/rfm56185.2022.10065256.

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Pugh, D., A. Valera-Medina, P. Bowen, A. Giles, B. Goktepe, J. Runyon, S. Morris, S. Hewlett, and R. Marsh. "Emissions Performance of Staged Premixed and Diffusion Combustor Concepts for an NH3/Air Flame With and Without Reactant Humidification." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-14953.

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Abstract Renewably generated ammonia offers a form of carbon-free chemical energy storage to meet the differences between uncertain renewable supply and fluctuating demand, and has the potential to support future energy requirements as a power-to-X concept. The storage and transportation characteristics of NH3 are favorable compared with H2, however there are significant combustion research challenges to enhance fuel reactivity whilst reducing harmful emissions production. The purpose of the presented work was to evaluate different fuel delivery concepts for a representative GT combustor. An experimental and numerical comparison was made between swirl-stabilized premixed and diffusion NH3-air flames at elevated inlet temperature (473 K). The exhaust NOx and unburned NH3 emissions generated from each concept were quantified to optimize operational combustor performance. High-speed OH* and NH2* chemiluminescence was employed to characterize the change in flame topology with variation in fuel-air equivalence ratio, and the resultant influence on measured emission concentrations. Chemiluminescence intensities were shown to elucidate changes in sampled exhaust emissions, enabling detailed analysis of intermediate chemistry. A comparison was made between experimental data and chemical kinetic simulations with a reactor network model, demonstrating the sensitivity of NOx emissions to premixed fuel-air equivalence ratio. A comparison was also made between exclusive primary airflow, and the staged introduction of secondary air, to quantify the change in NOx production between each configuration and improve fuel burnout. Secondary air loadings were incrementally increased through the combustor, and the change in exhaust emissions mapped. In addition, reactant humidification was employed as a secondary process for NOx reduction, having shown favorable performance with NH3/H2 mixtures to limit thermochemical NO production. The efficacy of humidification was compared for both premixed and diffusion configurations.
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Rai, A. K., R. S. Bhattacharya, M. Massey, O. L. Eryilmaz, and A. Erdemir. "Evaluation of Near Frictionless Carbon Coatings Using Four-Ball Wear Tester." In World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-63867.

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Near frictionless carbon (NFC) coatings were deposited in a large-area filtered cathodic arc system by plasma-enhanced chemical vapor deposition. An NFC coating with carbon-enriched TiC bond layers was deposited on half inch diameter steel (M50) balls. The four-ball wear test was used to evaluate the performance of the NFC coating. The endurance limit of the NFC coating was determined by starting the wear test at a relatively low load and increasing the load by a fixed amount after a given time interval to a final load at which the friction force reached a certain level. The four-ball wear test was conducted in fully flooded, starved, and dry lubrication conditions. MIL-PRF-23699 oil was the lubricant. Test results indicated a much higher endurance limit for the NFC-coated balls compared to that of uncoated balls.
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Dandeliya, Sushmita, and Anurag Srivastava. "Carbon Nanotube Based NH3 Gas Sensor: Ab-Initio Study." In 2015 IEEE International Symposium on Nanoelectronic and Information Systems (iNIS). IEEE, 2015. http://dx.doi.org/10.1109/inis.2015.54.

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Zhang, Songlin, Ayou Hao, Nam Nguyen, Abiodun Oluwalowo, Juhil Mahendra Ahir Ahir, Zhe Liu, Yourri Dessureault, Jin Gyu Park, and Richard Liang. "Pyrolyzed Polydopamine (py-pda) Functionalized Carbon Nanotubes and their Carbon/Carbon Composite with Improved Mechanical and Electrical Properties." In SAMPE 2019 - Charlotte, NC. SAMPE, 2019. http://dx.doi.org/10.33599/nasampe/s.19.1510.

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Mohammadpour, Ehsan, and Mokhtar Awang. "A finite element model for predicting the tensile behavior of carbon naotube." In 2011 National Postgraduate Conference (NPC). IEEE, 2011. http://dx.doi.org/10.1109/natpc.2011.6136394.

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Hasnahena, S. T., Biswarup Satpati, and Madhusudan Roy. "Enhanced sensing of NH3 gas by decorated multiwalled carbon nanotube." In DAE SOLID STATE PHYSICS SYMPOSIUM 2015. Author(s), 2016. http://dx.doi.org/10.1063/1.4947749.

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Endot, Nor Azam, and Ye Lwin. "Characterization of novel solvothermolysed dolomite for carbon dioxide separation from synthetic gas mixture." In 2011 National Postgraduate Conference (NPC). IEEE, 2011. http://dx.doi.org/10.1109/natpc.2011.6136277.

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Reports on the topic "NHC carbene"

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Fazekas, Andreas, and Scarleth Nuñez Castillo. NDC Invest Annual Overview 2020. Inter-American Development Bank, July 2021. http://dx.doi.org/10.18235/0003430.

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NDC INVEST is an IDB Group platform offering financial solutions and technical support to help build national goals and transform them into attainable plans that generate prosperous, resilient, and carbon neutral economies. Throughout the years closely supporting LAC countries, NDC INVEST has gained valuable experience and knowledge in designing and implementing concrete actions that lead to long-term climate resilience and net-zero emissions by 2050. In 2020, NDC INVEST confirmed its key role in successfully translating national climate commitments into physical and beneficial economic plans and transformational development projects. 331 initiatives have been supported in IDB Group regional member states through the IDB sovereign window, IDB Invest and IDB Lab. This publication highlights the successful work of NDC Invest in i.) developing relevant knowledge and building national capacities for long-term strategies (LTS), ii.) supporting countries in creating ambitious climate goals and NDCs, and iii.) implementing LTS and NDCs through financial strategies and investment plans.
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Chepeliev, Maksym. Development of the Air Pollution Database for the GTAP 10A Data Base. GTAP Research Memoranda, June 2020. http://dx.doi.org/10.21642/gtap.rm33.

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The purpose of this note is to document data sources and steps used to develop the air pollution database for the GTAP Data Base Version 10A. Emissions for nine substances are reported in the database: black carbon (BC), carbon monoxide (CO), ammonia (NH3), non-methane volatile organic compounds (NMVOC), nitrogen oxides (NOx), organic carbon (OC), particulate matter 10 (PM10), particulate matter 2.5 (PM2.5) and sulfur dioxide (SO2). The dataset covers four reference years – 2004, 2007, 2011 and 2014. EDGAR Version 5.0 database is used as the main data source. To assist with emissions redistribution across consumption-based sources, IIASA GAINS-based model and IPCC-derived emission factors are applied. Each emission flow is associated with one of the four sets of emission drivers: output by industries, endowment by industries, input use by industries and household consumption. In addition, emissions from land use activities (biomass burning) are estimated by land cover types. These emissions are reported separately without association with emission drivers.
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Gasim, Anwar, Lester C. Hunt, and Jeyhun Mikayilov. Baseline Forecasts of Carbon Dioxide Emissions for Saudi Arabia Using the Structural Time Series Model and Autometrics. King Abdullah Petroleum Studies and Research Center, May 2023. http://dx.doi.org/10.30573/ks--2022-dp19.

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To tackle the threat of climate change, countries worldwide have signed the Paris Agreement. This agreement aims to limit the global average temperature increase to below 2 degrees Celsius and potentially below 1.5 degrees Celsius above pre-industrial levels (UNFCCC 2015). Parties to the Paris Agreement are required to submit domestic climate plans detailing their mitigation measures, known as nationally determined contributions (NDCs). These plans detail countries’ ambitions and efforts to combat and respond to climate change. NDCs are communicated at five-year intervals, and each successive NDC must represent an increase in ambition over the previous one.
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Chepeliev, Maksym, Israel Osorio Rodarte, and Dominique van der Mensbrugghe. Distributional Impacts of Carbon Pricing Policies under Paris Agreement: Inter and Intra-Regional Perspectives. GTAP Working Paper, February 2021. http://dx.doi.org/10.21642/gtap.wp88.

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While bringing multiple benefits for the environment, achievement of the stringent global greenhouse gas emissions reduction target, like the one outlined in the Paris Climate Agreement, is associated with significant implementation costs and could impact different dimensions of human well-being, including welfare, poverty and distributional aspects. In this paper, we analyze the poverty and distributional impacts of different carbon pricing mechanisms consistent with reaching the Paris Agreement targets. We link a global recursive dynamic computable general equilibrium model ENVISAGE with the GIDD microsimulation model and explore three levels of mitigation effort and five carbon pricing options (trade coalitions). Results suggest that while there is a higher incidence of poverty in all scenarios, mainly driven by lower economic growth, Nationally Determined Contribution (NDC) policies result in progressive income distribution at the global level. Such progressivity is caused not only by lower relative prices of food versus non-food commodities, but also by a general decline in skill wage premia.
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Blair, Neal. A benthic carbon budget for the Continental Slope off Cape Hatteras, NC. Office of Scientific and Technical Information (OSTI), December 1999. http://dx.doi.org/10.2172/765626.

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Kalman, Joseph, and Maryam Haddad. Wastewater-derived Ammonia for a Green Transportation Fuel. Mineta Transportation Institute, July 2022. http://dx.doi.org/10.31979/mti.2021.2041.

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The energy-water nexus (i.e., availability of potable water and clean energy) is among the most important problems currently facing society. Ammonia is a carbon-free fuel that has the potential to reduce the carbon footprint in combustion related vehicles. However, ammonia production processes typically have their own carbon footprint and do not necessarily come from sustainable sources. This research examines wastewater filtration processes to harvest ammonia for transportation processes. The research team studied mock wastewater solutions and was able to achieve ammonia concentrations above 80%(nanofiltration) and 90% (reverse osmosis). The research team also investigated the influence of transmembrane pressure and flow rates. No degradation to the membrane integrity was observed during the process. This research used constant pressure combustion simulations to calculate the ignition delay times for NH3-air flames with expected impurities from the wastewater treatment processes. The influence of impurities, such as H2O, CO, CO2, and HCl, were studied under a range of thermodynamic conditions expected in compression ignition engines. The team observed carbon monoxide and water vapor to slightly decrease (at most 5%) ignition delay time, whereas HCl, in general, increased the ignition delay. The changes to the combustion chemistry and its influence of the reaction mechanism on the results are discussed. The experimental wastewater treatment study determined that reverse osmosis produced higher purity ammonia. The findings of the combustion work suggest that ignition delays will be similar to pure ammonia if HCl is filtered from the final product.
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Kalman, Joseph, and Maryam Haddad. Wastewater-derived Ammonia for a Green Transportation Fuel. Mineta Transportation Institute, July 2022. http://dx.doi.org/10.31979/mti.2022.2041.

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The energy-water nexus (i.e., availability of potable water and clean energy) is among the most important problems currently facing society. Ammonia is a carbon-free fuel that has the potential to reduce the carbon footprint in combustion related vehicles. However, ammonia production processes typically have their own carbon footprint and do not necessarily come from sustainable sources. This research examines wastewater filtration processes to harvest ammonia for transportation processes. The research team studied mock wastewater solutions and was able to achieve ammonia concentrations above 80%(nanofiltration) and 90% (reverse osmosis). The research team also investigated the influence of transmembrane pressure and flow rates. No degradation to the membrane integrity was observed during the process. This research used constant pressure combustion simulations to calculate the ignition delay times for NH3-air flames with expected impurities from the wastewater treatment processes. The influence of impurities, such as H2O, CO, CO2, and HCl, were studied under a range of thermodynamic conditions expected in compression ignition engines. The team observed carbon monoxide and water vapor to slightly decrease (at most 5%) ignition delay time, whereas HCl, in general, increased the ignition delay. The changes to the combustion chemistry and its influence of the reaction mechanism on the results are discussed. The experimental wastewater treatment study determined that reverse osmosis produced higher purity ammonia. The findings of the combustion work suggest that ignition delays will be similar to pure ammonia if HCl is filtered from the final product.
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Nicholson, Claire, Jonathan Wastling, Peter Gregory, and Paul Nunn. FSA Science Council Working Group 6 Food Safety and Net Zero Carbon July 2022 Interim Report. Food Standards Agency, July 2022. http://dx.doi.org/10.46756/sac.fsa.vxz377.

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The UK has a legal commitment to reach net zero carbon (NZC) emissions by 2050. This is a topic that has recently been building momentum, with clean growth being one of the four Grand Challenges set out by the UK Government. The ways we grow, process and transport food are major contributors to climate change, accounting for more than a quarter of all greenhouse gas emissions. Reducing this will require substantial changes in agriculture, manufacturing, and transport. Consequently, the Science Council and FSA Chief Scientific Adviser (CSA) agreed that a deeper understanding of the potential implications of achieving net zero on food systems, together with identification of areas of uncertainty, would be of considerable value to FSA in pre-empting future policy and evidence needs in this area. In early discussions to scope the work required, Defra indicated to the FSA Science Council Secretariat that there are many new developments and changes to activity in primary production aimed at achieving net zero. The Science Council agreed, therefore, to concentrate its first investigations on changes expected in primary food production. Primary production is the production of chemical energy in organic forms by living organisms. The main source of this energy is sunlight. For the purposes of this review, primary food production includes the growing and harvesting of plants as food for humans or feed for animals, and the rearing and slaughter of animals including livestock, fish and a wide variety of aquatic and marine organisms. A Science Council Working Group 6 (WG6) began work in summer 2021, led by Science Council members Mrs Claire Nicholson (WG6 Chair) and Prof Jonathan Wastling (WG6 Deputy Chair). The brief for WG6 is to investigate the potential food safety implications arising from changes to primary food production practices and technologies that reduce carbon emissions in the next 10 years. The work programme (described in this report) covers 4 phases, with phases 1 and 2 now complete. The work so far has drawn diverse, wide-ranging, sometimes slightly conflicting, views and opinions from across academia, the FSA, Defra, industry bodies and individual food producers. This interim report summarises: The work undertaken to date (phases 1 and 2) What has been learnt including changes to practice already underway or imminent Issues arising from the changes that the FSA should be aware of Further work planned by WG6 to understand the nature of the risks in more depth (phases 3 and 4) The Science Council aims to complete its investigations by the end of 2022 and present its findings to the FSA Board as soon as possible afterwards.
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9

Gummow. L51908 AC Grounding Effects on Cathodic Protection Performance in Pipeline Stations.pdf. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), December 2001. http://dx.doi.org/10.55274/r0010269.

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Most AC powered equipment at pipeline stations and at motorized valve sites isrequired, by code, to be electrically grounded to one or more ground electrodes. These grounding systems are normally electrically bonded to the AC power distribution grid, which can be quite extensive. Piping, either intentionally or inadvertently, is often connected to the AC electrical grounding grid in pipeline stations. Grounding grid conductors are usually bare and composed of copper or tinned copper, and ground rod materials can consist of a wide variety of metals such as copper-clad steel, carbon steel, stainless steel, galvanized steel, and galvanic anode alloys of zinc and magnesium. The interconnection of these grounding materials to the piping can increase the current requirements of the cathodic protection system, distort the current distribution pattern and complicate the accurate measurement of the pipe potentials. Benefit: The primary objective of this research project was to assess the impact of various types of grounding materials on the performance and testing of cathodic protection systems. The two major issues in this regard were the effects on current requirements and the accuracy of pipe-to-soil potential measurements. In addition, some related issues investigated as follows:the electrical resistance of each groundrod-to-earth was to be measured to determine whether or not there were any changes in the resistance-to-earth as a result cathodic polarization;the potential of galvanized steel was to be measured with increasing zinc consumption to determine if there is a well defined relationship between potential and zinc consumption; the National Electrical Code (NEC) was to be reviewed with respect to the insertion of AC coupling/DC isolating devices in series between the piping and the electrical grounding network. The results of this investigation were intended toprovide information to design more effective cathodic protection facilities for piping in pipeline stations having electrical grounding systems, anddetermine whether or not the resistance of the electrical grounding system increases as a result of receiving cathodic protection, andrecommend pipe-to-soil potential survey techniques to maximize measurement accuracy in the presence of an AC grounding grid, andevaluate the use of DC isolators/AC couplers to interconnect the piping to either the secondary or primary AC grounding system.
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10

Phuong, Vu Tan, Nguyen Van Truong, and Do Trong Hoan. Commune-level institutional arrangements and monitoring framework for integrated tree-based landscape management. World Agroforestry, 2021. http://dx.doi.org/10.5716/wp21024.pdf.

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Governance is a difficult task in the context of achieving landscape multifunctionality owing to the multiplicity of stakeholders, institutions, scale and ecosystem services: the ‘many-multiple’ (Cockburn et al 2018). Governing and managing the physical landscape and the actors in the landscape requires intensive knowledge and good planning systems. Land-use planning is a powerful instrument in landscape governance because it directly guides how actors will intervene in the physical landscape (land use) to gain commonly desired value. It is essential for sustaining rural landscapes and improving the livelihoods of rural communities (Bourgoin and Castella 2011, Bourgoin et al 2012, Rydin 1998), ensuring landscape multifunctionality (Nelson et al 2009, Reyers et al 2012) and enhancing efficiency in carbon sequestration, in particular (Bourgoin et al 2013, Cathcart et al 2007). It is also considered critical to the successful implementation of land-based climate mitigation, such as under Nationally Determined Contributions (NDCs), because the Land Use, Land-Use Change and Forestry (LULUCF) sector is included in the mitigation contributions of nearly 90 percent of countries in Sub-Saharan and Southern Asia countries and in the Latin American and Caribbean regions (FAO 2016). Viet Nam has been implementing its NDC, which includes forestry and land-based mitigation options under the LULUCF sector. The contribution of the sector to committed national emission reduction is significant and cost-effective compared with other sectors. In addition to achieving emission reduction targets, implementation of forestry and land-based mitigation options has the highest benefits for social-economic development and achieving the Sustainable Development Goals (MONRE 2020). Challenges, however, lie in the way national priorities and targets are translated into sub-national delivery plans and the way sub-national actors are brought together in orchestration (Hsu et al 2019) in a context where the legal framework for climate-change mitigation is elaborated at national rather than sub-national levels and coordination between government bodies and among stakeholders is generally ineffective (UNDP 2018). In many developing countries, conventional ‘top–down’, centralized land-use planning approaches have been widely practised, with very little success, a result of a lack of flexibility in adapting local peculiarities (Amler et al 1999, Ducourtieux et al 2005, Kauzeni et al 1993). In forest–agriculture mosaic landscapes, the fundamental question is how land-use planning can best conserve forest and agricultural land, both as sources of economic income and environmental services (O’Farrell and Anderson 2010). This paper provides guidance on monitoring integrated tree-based landscape management at commune level, based on the current legal framework related to natural resource management (land and forest) and the requirements of national green-growth development and assessment of land uses in two communes in Dien Bien and Son La provinces. The concept of integrated tree based landscape management in Viet Nam is still new and should be further developed for wider application across levels.
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