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Littérature scientifique sur le sujet « Modular catalysis »

Auteur : Grafiati

Publié le 19 avril 2025

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Articles de revues sur le sujet "Modular catalysis"

Khettar, Ibrahim, Alicja Malgorzata Araszczuk et Rosaria Schettini. « Peptidomimetic-Based Asymmetric Catalysts ». Catalysts 13, n^o 2 (21 janvier 2023) : 244. http://dx.doi.org/10.3390/catal13020244.

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Despite the great advantages of peptidomimetic scaffolds, there are only a few examples of their application in the field of asymmetric catalysis. Peptidomimetic scaffolds offer numerous advantages related to their easy preparation, modular and tunable structures, and biomimetic features, which make them well suited as chiral catalysts. This review underlines the structure–function relationship for catalytic properties towards efficient enantioselective catalysis.

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Burk, Mark J. « Modular Phospholane Ligands in Asymmetric Catalysis ». Accounts of Chemical Research 33, n^o 6 (juin 2000) : 363–72. http://dx.doi.org/10.1021/ar990085c.

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Llorente, Nuria, Héctor Fernández-Pérez, José L. Núñez-Rico, Lucas Carreras, Alicia Martínez-Carrión, Ester Iniesta, Andrés Romero-Navarro, Alba Martínez-Bascuñana et Anton Vidal-Ferran. « Efficient modular phosphorus-containing ligands for stereoselective catalysis ». Pure and Applied Chemistry 91, n^o 1 (28 janvier 2019) : 3–15. http://dx.doi.org/10.1515/pac-2018-0805.

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Abstract Over several years, our research team has contributed to ligand design for metal-catalyzed stereoselective transformations. This has been achieved with the synthesis and application to organic transformations of interest of an array of structurally diverse P-containing ligands. These range from highly modular enantiopure phosphine–phosphite ligands to supramolecularly regulated enantioselective phosphorus-based catalysts. Our research in supramolecular interactions has also led to the discovery of an unprecedented halogen-bonded rhodium-catalyst.

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Burk, Mark J. « ChemInform Abstract : Modular Phospholane Ligands in Asymmetric Catalysis ». ChemInform 31, n^o 36 (3 juin 2010) : no. http://dx.doi.org/10.1002/chin.200036267.

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Lin, Wenbin. « Metal-Organic Frameworks for Asymmetric Catalysis and Chiral Separations ». MRS Bulletin 32, n^o 7 (juillet 2007) : 544–48. http://dx.doi.org/10.1557/mrs2007.104.

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Metal-organic frameworks (MOFs) are an interesting class of molecule-based hybrid materials built from metal-connecting points and bridging ligands. MOFs have received much attention, owing to their potential impact on many technological areas, including gas storage, separation, and heterogeneous catalysis. The modular nature of MOFs endows them with facile tunability, and as a result, properly designed MOFs can yield ideal heterogeneous catalysts with uniform active sites through judicious choice of the building blocks. Homochiral MOFs, which can be prepared by numerous approaches (construction from achiral components by seeding with a chiral single crystal, templating with coordinating chiral co-ligands, and building from metal-connecting nodes and chiral bridging ligands), represent a unique class of materials for the economical production of optically pure compounds, whether through asymmetric catalysis or enantioselective inclusion of chiral guest molecules in their porous frameworks. As such, homochiral MOFs promise new opportunities for developing chirotechnology. This contribution provides a brief overview of recent progress in the synthesis of homochiral porous MOFs and their applications in asymmetric catalysis and chiral separations.

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Geri, Jacob B., Joanna L. Ciatti et Nathaniel K. Szymczak. « Charge effects regulate reversible CO2 reduction catalysis ». Chemical Communications 54, n^o 56 (2018) : 7790–93. http://dx.doi.org/10.1039/c8cc04370a.

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Modular but geometrically constrained ligands were used to investigate the impact of key ligand design parameters (charge and bite angle) on CO₂ hydrogenation and formic acid dehydrogenation activity.

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Dimian, Alexandre C., et Gadi Rothenberg. « An effective modular process for biodiesel manufacturing using heterogeneous catalysis ». Catalysis Science & ; Technology 6, n^o 15 (2016) : 6097–108. http://dx.doi.org/10.1039/c6cy00426a.

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Delpont, Nicolas, Imma Escofet, Patricia Pérez-Galán, Dirk Spiegl, Mihai Raducan, Christophe Bour, Riccardo Sinisi et Antonio M. Echavarren. « Modular chiral gold(i) phosphite complexes ». Catalysis Science & ; Technology 3, n^o 11 (2013) : 3007. http://dx.doi.org/10.1039/c3cy00250k.

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Xiong, Thao M., Edzna S. Garcia, Junfeng Chen, Lingyang Zhu, Ariale J. Alzona et Steven C. Zimmerman. « Enzyme-like catalysis by single chain nanoparticles that use transition metal cofactors ». Chemical Communications 58, n^o 7 (2022) : 985–88. http://dx.doi.org/10.1039/d1cc05578j.

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Schramm, Michael, Cindy Pham, Michelle Park, Jenny Pham et Sadie Martin. « Modular Preparation of Diverse Dipyrrolemethanes ». Synthesis 45, n^o 09 (10 avril 2013) : 1165–73. http://dx.doi.org/10.1055/s-0032-1318503.

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Thèses sur le sujet "Modular catalysis"

Camponovo, Francesco Patrizio. « Chiral ferrocenyl amidines as modular ligands for applications in asymmetric catalysis / ». Zürich : ETH, 2009. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=18199.

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Neri, Simona. « Tunable nanosystems for sensing and catalysis ». Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3424423.

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Au NP have emerged as versatile scaffolds for applications in sensing and catalysis due to their unique features such as high stability, biocompatibility, ease of preparation, size- and shape-dependent optical and electronic properties and high surface area to volume ratio. The surface of Au NP can be readily modified with ligands containing functional groups such as thiols, phosphines and amines, which exhibit strong affinity for gold surfaces. The cooperative and collective effects achieved by the organization of organic components on the particle provide all the characteristics of a multivalent surface. Multivalent interactions on the monolayer surface can, hence, be applied to strengthen an interaction between the surface and small molecules. In particular, the self-assembly of small molecules on the multivalent surface of Au NP permits the realization of dynamic complex chemical systems that can be applied in the fields of catalysis, sensing and for the creation of tunable materials. In the first part of this Thesis, the catalytic abilities of mixed monolayer gold nanoparticles composed of 8-trimethylammonium-octanethiol and different length thiols bearing the 4'-methyl-2,2'-bipyridine•Cu2+ complex has been studied. In particular, the influence of the geometry of the mixed monolayer gold nanoparticles on the efficiency and selectivity of the Diels-Alder reaction between cinnamoyl-1-methyl-1H-imidazole and cyclopentadiene has been studied. At the same time, the effect of the chiral environment obtained through the self-assembly of chiral peptide (Ac-(LLLL)-Leu-Leu-Gly-Trp-Ser(PO3H2)) on the enantioselection was evaluated. The results indicated in one case the formation of additional products. This can be justified considering the steric interactions between the alkyl chains and the catalysts when the catalytic headgroup is level with the monolayer surface. Furthermore, it was demonstrated that the self-assembly of a chiral enviroment on the surface of the Au NP can induce enantioselectivity, although only modestly. In the second part of the thesis, a modular indicator-displacement-assay is presented. Small molecules with biological relevance are selectively recognized under competitive conditions by using Au NP functionalized with thiols terminating with 1,4,7-triazacyclononane (TACN)•Zn2+. The assay relies on the change in affinity of macrocyclic receptors, such as cavitands, cyclodextrins or calixarenes, for monolayer protected gold nanoparticles upon complexation of the respective target analyte. This change affects the equilibrium between the nanoparticles and a fluorescent reporter molecule leading towards a change in intensity of the fluorescent output signal. The recognition modules can be changed in order to tune the selectivity of the assay without affecting the nature of the output signal. The combined use of recognition modules results in an assay able to detect multiple analytes simultaneously and with high selectivity. A study of the orthogonality of the different receptor-analyte couples led to the demonstration of the possible exploitation of these kinds of arrays within the context of molecular computing. In the third part, the possibility to self-assemble the molecular switch 4-(phenylazo)benzoic acid on the surface of Au NP functionalized with thiols terminating with 1,4,7-triazacyclononane (TACN)•Zn2+ was studied in order to reversibly modulate by light, the affinity of small molecules for the surface. The displacement studies of both probes 343Coumarin-GDDD and 6,8-dihydroxy-1,3-pyrenedisulfonic acid by cis/trans 4-(phenylazo)benzoic acid revealed that the two isomers have different affinities for the surface.This key point was then exploited to use light for the reversible up- and downregulation of the catalytic activity of the nanoparticle under investigation.
L’ importanza delle Au NP come supporto versatile per applicazioni nell’ambito della catalisi e dei sensori nasce dalle loro esclusive caratteristiche come, ad esempio, alta stabilità, biocompatibilità, facilità di preparazione, specifiche proprietà ottiche and elettroniche dipendenti dalla forma e dalle dimensioni e dal loro alto rapporto area/volume. Inoltre, la superficie delle Au NP può essere facilmente funzionalizzata mediante leganti contenenti vari gruppi funzionali, come tioli, fosfine e ammine che presentano alta affinità per la superficie d’oro. Gli effetti collettivi e cooperativi ottenuti grazie all’organizzazione di componenti organici sulla particella, fornisce multivalenza alla superficie. Le interazioni multivalenti sul monostrato possono, quindi, essere applicate per rafforzare un’interazione tra la superficie funzionalizzata e piccole molecole. In particolare l’auto assemblaggio di piccole molecole su una superficie multivalente permette la realizzazione di sistemi chimici dinamici che possono essere applicati nel campo della catalisi, dei sensori e per la creazione di sistemi regolabili. Nella prima parte della Tesi, viene studiata la capacità catalitica di nanoparticelle composte da un monostrato misto (in particolare composte da 8-trimetilammonio-octiltiolo e tioli di diversa lunghezza contenenti il complesso metallico 4’-metil-2,2’-bipiridina•Cu2+ . In particolare viene studiata l’influenza della geometria indotta dal monostrato misto sulla efficienza e selettività della reazione di Diels-Alder tra cinnamoil-1-metil-1H- imidazolo e il ciclopentadiene. Allo stesso tempo, viene studiato l’effetto dell’ambiente chirale ottenuto grazie all’autoassemblaggio di un peptide chirale (Ac-(LLLL)-Leu-Leu-Gly-Trp-Ser(PO3H2)) sulla enantioselettività della reazione. I risultati dimostrano che in alcuni casi la geometria può influenzare la formazione di prodotti addizionali. Questo può essere giustificato come il risultato di interazioni steriche tra catene alchiliche e catalizzatore, quando quest’ultimo si trova alla pari della superficie del monostrato. Inoltre, è stato dimostrato che, assemblando un peptide chirale sulla superficie delle Au NP, è possibile indurre enantioselettività, sebbene limitata. Nella seconda parte della Tesi viene presentato un saggio modulare basato sullo spiazzamento di un indicatore. Piccole molecole con rilevanza biologica sono selettivamente riconosciute utilizzando Au NP funzionalizzate con tioli che presentano come gruppo terminale il 1,4,7-triazaciclononano (TACN)•Zn2+. Il saggio si basa sul cambio di affinità di recettori macrociclici come, ad esempio cavitandi, ciclodestrine o calixareni, per le nanoparticelle, dopo avere formato il complesso con la loro rispettiva molecola bersaglio. Questo cambio influenza l’equilibrio tra nanoparticelle e una sonda fluorescente e provoca, di conseguenza, un cambio nel segnale di fluorescenza. I moduli di riconoscimento possono essere cambiati in modo da poter controllare la selettività del saggio senza influenzare la natura del segnale in uscita. L’ utilizzo contemporaneo di tre moduli permette di creare un sistema capace di rivelare più analiti simultaneamente e con alta selettività. Lo studio dell’ortogonalità delle differenti coppie recettore/analita permette di dimostrare la possibilità di utilizzo di questo tipo di sistemi nel campo dei computer molecolari. Nella terza parte viene studiata la possibilità di auto assemblare l’interruttore molecolare acido 4-(fenilazo)benzoico sulla superficie di Au NP funzionalizzate con tioli che presentano come gruppo terminale il 1,4,7-triazaciclononano (TACN)•Zn2+, con lo scopo di modulare con la luce (in modo reversibile) l’affinità di piccole molecole per la superficie. Gli studi di spiazzamento di entrambi i probe cumarina343-GDDD e l’acido 6,8-diidrossi-1,3-pirenedisulfonico promosso dal cis/trans acido 4-(fenilazo)benzoico rivelano che i due isomeri hanno diverse affinità per la superficie delle nanoparticelle. Questo punto chiave viene sfruttato per permettere la regolazione tramite luce dell’attività delle nanoparticelle in esame.

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Vinci, Daniele. « Modular approach to the synthesis of new chiral phosphine ligands and their application in catalysis ». Thesis, University of Liverpool, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426131.

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Meise, Markus [Verfasser]. « Modular synthesis of hyperbranched polyglycerol supported N-heterocyclic carbene ligands for application in catalysis / Markus Meise ». Berlin : Freie Universität Berlin, 2009. http://d-nb.info/1023624427/34.

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Holstein, Philipp. « Enantioselective C(sp3)-H Arylation and Development of a Modular C(sp3)-H Alkenylation ». Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10286.

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Récemment, l'activation C-H catalysée par des métaux de transition est devenue un outil performant pour construire des liaisons carbone-carbone et carbone hétéroatome à partir de liaisons C-H omniprésentes dans les molécules organiques. Bien que l'activation des liaisons C-H aromatiques ait été largement étudiée ces dernières années, celle des liaisons C-H aliphatiques représente encore un domaine faiblement exploré. Notre équipe s'est depuis plusieurs années intéressée au développement méthodologique de l'activation C(sp3)-H et à son application en synthèse de produits naturels et molécules bioactives. Dans la continuité des récents travaux sur la version asymétrique de cette réaction, cette thèse décrit le développement et la synthèse de nouveaux ligands du type Binepine. Ces ligands chiraux et monodentates nous ont permis de réaliser la synthèse d'indanes chiraux possédant un centre asymétrique quaternaire, de manière hautement énantio- et diastéréosélective. Cette réaction présente comme avantages l'utilisation d'une faible charge catalytique et d'une température de réaction inférieure à 100 °C, sans aucun additif. Le champ d'application de la réaction inclut notamment l'activation des liaisons C-H d'un groupement méthylène, donnant ainsi accès à des systèmes fusionnés, tricycliques. La construction de molécules non-aromatiques via une alcénylation C-H intramoléculaire a été récemment décrite et s'avère très prometteuse pour la synthèse de produits naturels saturés. Dans la continuité de ces travaux innovants, nous avons développé la synthèse de γ-lactames à partir de bromoalcènes acycliques. Cette nouvelle réaction permet de construire de manière simple et efficace des hétérocycles a cinq chainons de façon modulaire, donnant ainsi la possibilité d'envisager des nouvelles déconnections rétrosynthétiques, complémentaires des méthodes déjà établies. Cette nouvelle méthode a pu être appliquée à la synthèse totale de l'alcaloïde marin Plakoridine A, dont la structure centrale cyclique a été synthétisée en quatre étapes avec un rendement global de 37%
Recently, transition-metal-catalyzed C-H activation has emerged as a powerful tool to transform stable C-H bonds into carbon-carbon or carbon-heteroatom bonds. While the activation of aromatic C-H bonds has seen a tremendous development, less effort has been devoted to the more challenging activation of aliphatic C-H bonds. Our group has a long-standing interest in the development of C(sp3)-H activation reactions and their application in the synthesis of natural products and bioactive compounds. In line with previous efforts to develop an asymmetric C(sp3)-H activation, the herein presented work details the synthesis of new Binepine ligands. These monodentate, chiral ligands enabled us to realize a highly dia- and enantioselective C(sp3)-H activation reaction allowing the construction of chiral quaternary carbon centers. Strong points of this robust method are the low catalyst loading, the low reaction temperature and the absence of additives. The substrate scope includes the rare activation of methylene C-H bonds leading to fused tricyclic carbocycles and heterocycles. The construction of non-aromatic molecules through intramolecular C-H alkenylation was recently disclosed and has great potential for the construction of saturated natural products. Based on seminal work, we have developed the synthesis of valuable γ- lactams from acyclic bromoalkenes. This new methodology offers a powerful way to build simple, five-membered N heterocycles in a modular fashion. Notably, it enables a new retrosynthetic disconnection which is complementary to conventional approaches. Finally, we set out to showcase its utility as key step in the total synthesis of the pyrrolidine alkaloid Plakoridine A. The cyclic core structure was accessed in four steps and 37% overall yield

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Fernández, Pérez Héctor. « Towards highly efficent ligands for asymmetric hydrogenations : a covalent modular approach and investigations into bio-inspired supramolecular strategies ». Doctoral thesis, Universitat Rovira i Virgili, 2009. http://hdl.handle.net/10803/9041.

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La preparación de nuevos ligandos quirales P-OP (fosfina-fosfinitos y fosfina-fosfitos), fácilmente preparados con una estrategia sintética en dos etapas desde una aproximación covalente, es descrita en la presente Tesis Doctoral. El mejor catalizador de la serie ha demostrado tener propiedades catalíticas excelentes en la hidrogenación asimétrica catalizada por rodio de una amplia variedad de olefinas funcionalizadas. El resultado excelente y el diseño modular de los ligandos sintetizados hacen éstos muy atractivos para futuras aplicaciones.
La presente Tesis Doctoral describe también la preparación de nuevos ligandos quirales que pueden comportarse como catalizadores supramoleculares inspirados en el mecanismo de regulación alostérica de los enzimas.
A library of enantiomerically pure P-OP ligands (phosphine-phoshinites and phosphine-phosphites) straightforwardly available in two synthetic steps from enantiopure Sharpless epoxy ethers is reported in the present PhD. Thesis. The "lead" catalyst of the series has proven to have outstanding catalytic properties in the rhodium-catalysed asymmetric hydrogenation of a wide variety of functionalised alkenes. Their excellent performance and modular design makes them attractive for future applications.
This PhD. Thesis also reports the development of a practical route to chiral diphosphine ligands with supramolecular motifs, with potential for allosteric modulation, which we prepared for future catalytic studies.

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Rahm, Fredrik. « Chiral Pyridine-Containing Ligands for Asymmetric Catalysis. Synthesis and Applications ». Doctoral thesis, KTH, Chemistry, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3564.

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This thesis deals with the design and syntheses of chiral,enantiopure pyridinecontaining ligands and their applicationsin asymmetric catalyis.

Chiral pyridyl pyrrolidine ligands and pyridyl oxazolineligands were synthesized and employed in thepalladium-catalysed allylic alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate. Theinfluence of the steric properties of the ligands wereinvestigated.

Ditopic ligands, containing crown ether units as structuralelements, were synthesized and some of the ligands were used asligands in the palladiumcatalysed allylic alkylation of1,3-diphenyl-2-propenyl acetate with dimethyl malonate. A smallrate enhancement was observed, compared with analogous ligandslacking the crown ether unit, when these ditopic ligands wereused in dilute systems.

A modular approach was used to synthesize chiralenantiomerically pure pyridyl alcohols and C2-symmetric2,2-bipyridines, with the chirality originating from thechiral pool. Electronic and steric properties of the compoundswere varied and they were used as ligands in theenantioselective addition of diethylzinc to benzaldehyde. Thesense of asymmetric induction was found to be determined by theabsolute configuration of the carbinol carbon atom. Theelectronic properties of the ligands had a minor influence onthe levels of enantioselectivity induced by the ligands.

Chiral pyridyl phosphinite ligands and pyridyl phosphiteligands were synthesized from the pyridyl alcohols andevaluated as ligands in palladiumcatalysed allylic alkylations.With the phosphinite ligands, the sense of chiral induction wasfound to be determined by the absolute configuration of theformer carbinol carbon atom. A kinetic resolution of theracemic starting material was observed with one of thephosphite ligands. Moderate enantioselectivities wereachieved.

Kewords:asymmetric catalysis, chiral ligand, chiralpool, oxazoline, crownether, ditopic receptor, bipyridine,pyridyl alcohol, modular approach, P,Nligand, diethylzinc,allylic alkylation.

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Decan, Matthew. « The Copper(I)-catalyzed Azide–Alkyne Cycloaddition : A Modular Approach to Synthesis and Single-Molecule Spectroscopy Investigation into Heterogeneous Catalysis ». Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31882.

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Click chemistry is a molecular synthesis strategy based on reliable, highly selective reactions with thermodynamic driving forces typically in excess of 20 kcal mol-1. The 1,3-dipolar cycloaddition of azides and alkynes developed by Rolf Huisgen saw dramatic rate acceleration using Cu(I) as a catalyst in 2002 reports by Barry Sharpless and Morten Meldal enabling its click chemistry eligibility. Since these seminal reports, the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) has become the quintessential click reaction finding diverse utility. The popularity of the CuAAC has naturally led to interest in new catalyst systems with improved efficiency, robustness, and reusability with particular focus on nanomaterial catalysts, a common trend across the field of catalysis. The high surface area of nanomaterials lends to their efficacy as colloidal and heterogeneous nanocatalysts, but the latter boasts the added benefit of easy separation and recyclability. With any heterogeneous catalyst, a common question arises as to whether the active catalyst species is truly heterogeneous or rather homogeneous through metal ion leaching. Differentiating these processes is critical, as the latter would result in reduced efficiency, higher cost, and inevitable environmental and heath side effects. This thesis explores the CuAAC from an interdisciplary approach. First as a synthetic tool, applying CuAAC-formed triazoles as functional, modular building blocks in the synthesis of optical cation sensors by combining azide and alkyne modified components to create a series of sensors selective for different metal cations. Next, single-molecule spectroscopy techniques are employed to observe the CuNP-catalyzed CuAAC in real time. Combining bench-top techniques with single-molecule microscopy to monitor single-catalytically generated products proves to be an effective method to establish catalysis occurs directly at the surface of copper nanoparticles, ruling out catalysis by ions leached into solution. This methodology is extended to mapping the catalytic activity of a commercial heterogeneous catalyst by applying super-localization analysis of single-catalytic events. The approach detailed herein is a general one that can be applied to any catalytic system through the development of appropriate probes. This thesis demonstrates single-molecule microscopy as an accessible, effective, and unparalleled tool for exploring the catalytic activity of nanomaterials by monitoring single-catalytic events as they occur.

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Pedrazzini, T. « MODULAR APPROACH TO CHIRAL PYRIDINE CONTAINING MACROCYCLES : SYNTHESIS, CHARACTERIZATION, REACTIVITY AND CATALYTIC ACTIVITY OF THEIR METAL COMPLEXES ». Doctoral thesis, Università degli Studi di Milano, 2014. http://hdl.handle.net/2434/243662.

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In this thesis is reported a simple, fast, economic modular approach for the synthesis of chiral tetraaza-macrocycles containing a pyridine ring (Pc-L*) starting from aminoacids. The characterization of the ligands and of their complexes with copper (I) and silver (I) salts also descrive, including several crystal suitable for X-ray determination. The organometallic reactivity and coordination behavior of these complexes with CO and acetonitrile has been studied. The complexes were succesfully applied as catalysts for cyclopropanation and A3-coupling reaction and for the synthesis of isochromenes starting from propargyl-aldehydes. In any case, excellent results in terms of yields and chemoselectivity were obtained and, concerning the cyclopropanation reaction, very good enantioselectivities on different substrates were achieved. Furthermore, a new class of Pc-L* ligands potentially dianionic is described and the complexation studies of these macrocycles with ruthenium, cobalt, zyrconium and iron are reported.

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Naeemi, Qaseem [Verfasser]. « Studies in Enantioselective Transition Metal Catalysis Using Modular Phosphine-Phosphite Ligands Copper-catalyzed 1,4-Addition of Grignard Reagents to alpha,beta-Unsaturated Carbonyl Compounds / Qaseem Naeemi ». München : Verlag Dr. Hut, 2012. http://d-nb.info/1020299428/34.

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Livres sur le sujet "Modular catalysis"

Small Modular Reactors : Advances in SMR Developments 2024. INTERNATIONAL ATOMIC ENERGY AGENCY, 2024. http://dx.doi.org/10.61092/iaea.3o4h-svum.

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This publication aims to provide Member States with a concise overview of the latest developments regarding SMR technology worldwide. It explores SMRs under development, their potential growth trajectory, and the lifecycle of SMR development from concept to decommissioning. It also examines the unique global role the IAEA plays in supporting the establishment of sustainable nuclear power programmes and in catalysing technology development and deployment in Member States including through efforts such as the SMR Platform and the Nuclear Harmonization and Standardization Initiative (NHSI). Most data presented in this publication come from the 2024 update to the ARIS database. Publications on the status of SMR technology developments have been published in 2011, 2012, 2014, 2016, 2018, 2022 and 2024.

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Chapitres de livres sur le sujet "Modular catalysis"

DuBois, M. Rakowski, et Daniel L. DuBois. « A Modular Approach to the Development of Molecular Electrocatalysts for H2 Oxidation and Production Based on Inexpensive Metals ». Dans Catalysis without Precious Metals, 165–80. Weinheim, Germany : Wiley-VCH Verlag GmbH & Co. KGaA, 2010. http://dx.doi.org/10.1002/9783527631582.ch7.

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Gade, Lutz H. « Modular Assembly of Chiral Catalysts with Polydentate Stereodirecting Ligands ». Dans Molecular Catalysts, 313–42. Weinheim, Germany : Wiley-VCH Verlag GmbH & Co. KGaA, 2014. http://dx.doi.org/10.1002/9783527673278.ch15.

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Veser, G., G. Friedrich, M. Freygang et R. Zengerle. « A Modular Microreactor Design for High-Temperature Catalytic Oxidation Reactions ». Dans Microreaction Technology : Industrial Prospects, 674–86. Berlin, Heidelberg : Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-642-59738-1_71.

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Cockburn, Darrell W., Casper Wilkens et Birte Svensson. « Affinity Electrophoresis for Analysis of Catalytic Module–Carbohydrate Interactions ». Dans Methods in Molecular Biology, 91–101. New York, NY : Springer US, 2023. http://dx.doi.org/10.1007/978-1-0716-3151-5_6.

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Cockburn, Darrell, Casper Wilkens et Birte Svensson. « Affinity Electrophoresis for Analysis of Catalytic Module-Carbohydrate Interactions ». Dans Methods in Molecular Biology, 119–27. New York, NY : Springer New York, 2017. http://dx.doi.org/10.1007/978-1-4939-6899-2_9.

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Burk, Mark, et James Ramsden. « Modular, Chiral P-Heterocycles in Asymmetric Catalysis ». Dans Handbook of Chiral Chemicals, Second Edition, 249–68. CRC Press, 2005. http://dx.doi.org/10.1201/9781420027303.ch13.

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Zhu, S. « 1.13 Nickel-Catalyzed Cross Coupling Involving Alkenes ». Dans Base-Metal Catalysis 1. Stuttgart : Georg Thieme Verlag KG, 2023. http://dx.doi.org/10.1055/sos-sd-238-00251.

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AbstractNickel-catalyzed functionalization of alkenes to give value-added products in a manner that is rapid, selective, and modular has resulted in tremendous advances in synthetic chemistry. Great progress has been achieved in nickel-catalyzed (migratory) hydrofunctionalization and difunctionalization of alkenes over the past few years. In the first half of this chapter, nickel-catalyzed (migratory) hydrofunctionalization of alkenes is described. The second half details nickel-catalyzed difunctionalization of alkenes. Both reductive and redox-neutral reactions are discussed.

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C.J., Love, C. D. Andrews et R. E. Morris. « The preparation of modular porous solids from zeolite-like building blocks ». Dans Studies in Surface Science and Catalysis, 133–38. Elsevier, 2004. http://dx.doi.org/10.1016/s0167-2991(04)80793-6.

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Hagemeyer, A., et A. Volpe. « Catalysts : Combinatorial Catalysis ». Dans Reference Module in Materials Science and Materials Engineering. Elsevier, 2016. http://dx.doi.org/10.1016/b978-0-12-803581-8.01004-3.

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Zhang, Weijie, et Sen Zhang. « Catalysts : Combinatorial heterogeneous catalysis ». Dans Reference Module in Materials Science and Materials Engineering. Elsevier, 2023. http://dx.doi.org/10.1016/b978-0-323-90800-9.00201-8.

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Actes de conférences sur le sujet "Modular catalysis"

O’Brien, Christopher, Michael Leshchiner et Todd M. Ryan. « Design and Demonstration of a Multi-Fuel Automotive Fuel Processor With Novel Catalyst Integration and Rapid Control System ». Dans ASME 2008 6th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2008. http://dx.doi.org/10.1115/fuelcell2008-65238.

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A complete automotive onboard multi-fuel fuel processing system (FPS) that addresses some of the key issues of catalyst utilization, fuel cell integration, and control has been developed and tested, producing up to 1.2 grams per second of hydrogen flow in a total package volume of 150 liters. The reforming reaction train includes an autothermal reforming (ATR) zone, water-gas shift (WGS), and preferential oxidation (PrOx), all integrated with heat exchange to preheat reactants and generate process steam. The WGS and PrOx catalysts are integrated on metallic supports within a novel modular catalyst coated heat exchanger design that incorporates catalytic reaction, air preheat, and steam generation in a single device. The use of the catalyst coated heat exchangers eliminates the need for separate high-temperature shift and low-temperature shift zones; these are replaced by a continuously cooled single WGS zone. Due to the novel integration of catalytic heat exchangers, this FPS uses approximately half the catalyst per unit hydrogen produced than the previous generation, allowing for significant cost reduction.

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Dutta, P., L. H. Cowell, D. K. Yee et R. A. Dalla Betta. « Design and Evaluation of a Single-Can Full Scale Catalytic Combustion System for Ultra-Low Emissions Industrial Gas Turbines ». Dans ASME 1997 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/97-gt-292.

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The goal of the Advanced Turbine Systems (ATS) program is the design and development of high thermal efficiency gas turbines with pollutant emissions at single digit levels, through the development of advanced recuperated gas turbines. Following successful subscale catalytic reactor testing, a full scale catalytic combustion system was designed to be representative of a single can in a multi-can gas turbine combustor configuration. The full scale catalytic combustion system is modular in design and includes a fuel/air premixer upstream of the catalytic reactor and a post catalyst homogeneous combustion zone downstream of the catalyst bed to complete the homogeneous gas-phase reactions. System start-up is accomplished using a lean-premixed (LP) low emissions fuel injector. The system transitions to catalyst operation using a variable geometry valve that diverts air flow into the catalyst at loads greater than 50% of full load. The variable geometry valve is used to operate the catalyst within the narrow operating window due to limited fuel/air turndown allowed by the catalyst. A catalyst design with preferential catalyst coating on a corrugated metal substrate to limit catalyst substrate temperatures was selected for the system. Mean fuel concentration measurements at the inlet to the catalyst bed using an instrumented catalyst module showed the fuel/air premixing to be within catalyst specifications. Preliminary combustion tests on the system were completed. The catalytic combustion system was tested over the 50-to-100% load range. Using variable geometry control, emissions goals (< 5 ppmv NOx, < 10 ppmv CO and UHC corrected to 15% O2) were achieved for catalyst operation between 50-and-100% load conditions. The system was started and operated under part-load conditions using the LP injector. Efforts are under way to accomplish successful transition from LP mode of operation to catalytic mode of operation using the variable geometry system.

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Baird, Benjamin, Shahrokh Etemad, Hasan Karim, Sandeep Alavandi et William C. Pfefferle. « Ultra Low NOx Using Rich Catalytic/Lean-Burn Catalytic Pilots : Gas Turbine Engine Test ». Dans ASME Turbo Expo 2009 : Power for Land, Sea, and Air. ASMEDC, 2009. http://dx.doi.org/10.1115/gt2009-60258.

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Lean premixed (LP) combustion is limited to a minimum NOx of 5–9 ppm due to flame stability. To improve flame stability and lower NOx, an advanced Rich Catalytic Lean-burn technology was developed and integrated to replace only the injector pilot with catalyst modules. This system focuses on replacing the highest temperature zone of the LP combustion system with a catalytic pilot (which can stabilize the main flame at reduced equivalence ratio) to reduce overall NOx emissions. This concept synergistically combines the best features of catalytic and aerodynamically stabilized combustion technologies. During Taurus 70 (T70) engine testing of a set of injectors equipped with catalyst modules for natural gas applications, emissions at baseload conditions were NOx of ∼ 2.5 ppmv and CO less than 2 ppm, both corrected to 15% O2. Low single digit emissions were achieved from 50% to 100% load. Combustor acoustics were low (below 0.1 psi/690 Pa) during testing. Reactor catalyst temperature was within the design limit and no-preburner was required. The initial emissions results are promising providing an alternative to conventional LP technology for less than 5 ppm NOx systems. Further development work is needed to establish engine integration and long term catalyst durability before advancing to production.

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Fisher, Mark D., et George A. Davies. « Flow Analysis Helps Correct Underperformance of Combined Cycle Emissions Equipment ». Dans ASME 2006 Power Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/power2006-88209.

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Computational fluid dynamics analysis of the exhaust gas flow distribution in the inlet ductwork of a combined cycle power plant has helped improve both emissions performance as well as lowering plant operating costs. The Turlock Irrigation District Almond Power plant had recently installed an upgraded gas turbine (GT), and replaced both CO oxidation and selective catalytic control (SCR) NOx control catalysts in order to withstand the higher exhaust temperatures of the new gas turbine. After the retrofits, both NOx and CO emissions were within Permitted limits, but were above expected values, and operators found that overspray of ammonia was required to meet required NOx values of 3.0 ppmv at 15% O2. The need to overspray also resulted in unacceptably high levels of ammonia slip at the stack. Following investigations which included physical flow modeling of the ductwork, TID opted to have the exhaust gas flow numerically modeled to confirm the origin of the emissions problem and identify and implement a long-term resolution. Computational fluid dynamics (CFD) analyses confirmed that the cause of the poor emissions performance was highly biased gas flow distributions at the entrance to the CO catalyst modules and the ammonia injection grid (AIG). Using multiple models to evaluate alternate configurations of flow control devices, a single distribution grid located upstream of the CO catalyst modules was designed to provide improved flow distributions at both the CO catalyst, AIG, and SCR catalysts. Field tests of the plant with the installed distribution grid confirmed that the retrofit significantly improved emissions performance while reducing both required ammonia injection flows and ammonia slip values eight-fold. This not only allowed the plant to meet and exceed required emissions levels, but also reduced ammonia injection flow rates by a minimum of 40%. Additionally, the facility has seen an improvement in the plant’s effective operating range. This is the range at which the plant can operate and still maintain emissions compliance. Prior to the installation of the distribution grid the plant had an effective operating range of 30–50 MW. The plant now has an effective operating range of 20–50 MW. This is beneficial at times when the plant is operated in “load following” mode.

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Nabidollayev, S. « Development and Improvement of the Membrane Purification System of Gas Emissions in Various Industrial Sectors ». Dans SPE Caspian Technical Conference and Exhibition. SPE, 2023. http://dx.doi.org/10.2118/217557-ms.

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Abstract The issue of harmful emissions into the atmosphere poses a significant threat to the environment and human health. In various industrial sectors such as energy production, chemical industry, metallurgy, and the oil and gas sector, the release of harmful gas emissions is becoming an increasingly significant problem. These emissions contain toxic substances that can lead to air pollution, climate change, and respiratory diseases. The development and enhancement of gas emission treatment using membrane systems is becoming a crucial area of research. The aim of such research is to explore new methods, materials, and processes that ensure the efficient and environmentally safe removal of harmful components from gas emissions. This will help mitigate the adverse impact on the environment and provide a healthier atmosphere for all living organisms. The research presented in this study, which focuses on the development and improvement of membrane-based gas emission treatment systems, plays a pivotal role in various industrial sectors. The objective of this research is to seek new approaches and technologies that will effectively purify gas emissions, thereby reducing their negative impact on the environment. The topic of this article describes the enhancement of the membrane-based gas emission treatment system across various industries and encompasses several potential improvement aspects: New Membrane Materials and Designs: The invention may involve the development and utilization of novel materials for membranes with enhanced characteristics, such as high permeability to target pollutants and resistance to aggressive substances. Furthermore, the invention could encompass innovative membrane designs to achieve more efficient gas emission purification. Enhancement of Modular System: The invention could entail improving the modular membrane system, including optimizing module geometry, improving gas flow distribution, and enhancing module structural integrity. This would result in a more efficient and reliable gas emission treatment. Integration with Other Purification Methods: The invention may involve integrating the membrane system with other purification methods, such as sorption processes, catalytic treatment, or photocatalytic purification. This comprehensive integration would achieve a more thorough gas emission purification. Development of Monitoring and Control Systems: The invention could encompass the development of new monitoring and control systems for precise process monitoring and system optimization. This may include utilizing sensors for gas flow quality control, automated process parameter adjustment, and optimal control algorithms. The advantages of the technology of replacing catalysts in the gas emission pipe using the drum-based rapid membrane replacement system include: Efficiency and Swiftness: The drum system enables rapid membrane replacement without interrupting the production process, significantly reducing the time required for catalyst renewal and system restoration. Reduced Downtime: Quick membrane replacement reduces production downtime as the catalyst renewal process takes less time. This enhances overall productivity and minimizes losses. Enhanced Reliability: The drum-based system ensures simpler and more reliable membrane replacement. It eliminates the need for complex and labor-intensive catalyst replacement procedures, minimizing the possibility of errors or damage. Time and Resource Savings: Rapid membrane replacement reduces technical maintenance and catalyst replacement costs, leading to production time and resource savings. Increased Flexibility: The drum system allows easy adaptation of catalyst types and compositions according to process requirements, boosting production flexibility and the ability to respond swiftly to market changes and technological demands. Improved Environmental Safety: Rapid membrane replacement helps maintain efficient gas emission treatment, reducing the release of harmful substances into the environment and enhancing ecological safety. The prototypes of this invention are revolving replacement systems. This system is based on the revolving principle, where several membranes or catalysts are placed on a platform that can rotate or move between different positions. Despite these advantages, the revolving replacement system also presents potential drawbacks: Limited Position Capacity: The revolving system usually has a limited number of positions for membranes or catalysts. If a large variety of elements needs to be used, the system's size might need to be increased, or additional revolving mechanisms may be required. Maintenance Complexity: The device of the revolving system may be complex to maintain and service. Regular cleaning, lubrication, and mechanism condition monitoring may require additional efforts and skills. Potential for Malfunctions: The revolving system is a mechanical device with moving parts, which entails a potential risk of breakdowns or failures. Improper use or inadequate maintenance could lead to unexpected situations and production downtime. Precise Calibration Requirements: The revolving system demands accurate calibration and alignment for proper operation. Deviations in alignment or calibration could result in malfunctions or uneven gas flow distribution. Additional Costs: Implementing the revolving membrane replacement system incurs additional expenses for development, manufacturing, and installation. Additionally, the need for regular technical maintenance and updates could lead to extra operational costs. All these drawbacks can be addressed and minimized through meticulous design, high-quality manufacturing, and regular system maintenance.

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Smith, Duane A., Steve F. Frey, David M. Stansel et Mohan K. Razdan. « Low Emissions Combustion System for the Allison ATS Engine ». Dans ASME 1997 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/97-gt-311.

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This paper describes the development of an ultra-low emissions combustion system for Allison’s Advanced Turbine System (ATS) engine, which is being developed in cooperation with the U.S. Department of Energy. The simple cycle engine is designed to have a thermal efficiency that is 15% better than today’s best in class engine, and exhaust emissions of 9 ppm NOx, 20 ppm CO, and 20 ppm UHC. The approach taken to meet the low emissions goals is based on ultra-lean premixed fuel-air combustion supported by a catalyst. The progress toward development and integration of lean premix (LPM), catalytic and post-catalytic stages, and the combustor-to-turbine transition duct into an overall ATS combustion system is presented. A parametric computational fluid dynamics (CFD) study was conducted on the performance of lean premix modules at ATS conditions. Various lean premix modules were tested extensively under atmospheric conditions to determine airflow capacity, flashback propensity, lean blowout (LBO) fuel-air ratios, and fuel concentration profiles at the module exit. Kinetic modeling using the GRI mechanism has been used to estimate ignition delay times in the post-catalytic zone. Comparison between the modeling results and experimental data at high pressure shows good agreement. A detailed computational analysis was performed to design the combustion-to-turbine transition duct. The results indicate that the scroll duct configuration produces an acceptable mass flow uniformity and swirl angle exiting the duct into the turbine section. High pressure sector rig tests have been performed to evaluate staging interaction issues. The results indicate that the series staged approach can facilitate incorporation of the catalytic combustion system by expanding the operability range. NOx emissions levels of 9 ppm or less can be sustained over a wide range of equivalence ratios.

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Tehrani, Mehran, Masoud Safdari, Scott W. Case et Marwan S. Al-Haik. « Using Multiscale Carbon Fiber/Carbon Nanotubes Composites for Damping Applications ». Dans ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/smasis2011-5087.

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A novel technique to grow carbon nanotubes (CNTs) on the surface of carbon fibers in a controlled fashion using simple lab set up is developed. Growing CNTs on the surface of carbon fibers will eliminate the problem of dispersion of CNTs in polymeric matrices. The employed synthesis technique retains the attractive feature of uniform distribution of the grown CNTs, low temperature of CNTs’ formation, i.e. 550 °C, via cheap and safe synthesis setup and catalysts. A protective thermal shield of thin ceramic layer and subsequently nickel catalytic particles are deposited on the surface of the carbon fiber yarns using magnetron sputtering. A simple tube furnace setup utilizing nitrogen, hydrogen and ethylene (C2H4) were used to grow CNTs on the carbon fiber yarns. Scanning electron microscopy revealed a uniform areal growth over the carbon fibers where the catalytic particles had been sputtered. The structure of the grown multiwall carbon nanotubes was characterized with the aid of transmission electron microscopy (TEM). Dynamical mechanical analysis (DMA) was employed to measure the loss and storage moduli of the hybrid composite together with the reference raw carbon fiber composite and the composite for which only ceramic and nickel substrates had been deposited on. The DMA tests were conducted over a frequency range of 1–40 Hz. Although the storage modulus remained almost unchanged over the frequency range for all samples, the loss modulus showed a frequency dependent behavior. The hybrid composite obtained the highest loss modulus among other samples with an average increase of approximately 25% and 55% compared to composites of the raw and ceramic/nickel coated carbon fibers, respectively. This improvement occurred while the average storage modulus of the hybrid composite declined by almost 9% and 15% compared to the composites of reference and ceramic/nickel coated samples, respectively. The ultimate strength and elastic moduli of the samples were measured using standard ASTM tensile test. Results of this study show that while the addition of the ceramic layer protects the fibers from mechanical degradation it abolishes the mechanisms by which the composite dissipates energy. On the other hand, with almost no compromise in weight, the hybrid composites are good potential candidate for damping applications. Furthermore, the addition of CNTs could contribute to improving other mechanical, electrical and thermal properties of the hybrid composite.

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Davis, James S., et G. C. Duponteil. « Selective Catalytic Reduction Impact on Heat Recovery Steam Generator Design and Operation ». Dans ASME 1986 International Gas Turbine Conference and Exhibit. American Society of Mechanical Engineers, 1986. http://dx.doi.org/10.1115/86-gt-72.

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Selective Catalytic Reduction (SCR) is a post-combustion method to reduce the oxides of nitrogen (NOx), present in flue gases such as gas turbine exhaust streams, to N2 and water. It involves the injection of ammonia and the use of a catalyst module to promote the reaction to obtain high efficiency (60–86+%) NOx reduction. Several operating parameters can influence catalyst performance to include temperature, gas flow distribution, presence of sulfur compounds and catalyst age. This paper examines the impact of a SCR integration in a gas turbine heat recovery steam generator (HRSG) design/operation. Limitations on HRSG load and following capabilities, effect on capital cost and overall performance and current SCR system experience represent a number of areas that are examined.

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Downey, Markus, et Ulrich Pfahl. « Advanced Metal Substrate Technology for Large Engine Exhaust Gas Aftertreatment Systems ». Dans ASME 2011 Internal Combustion Engine Division Fall Technical Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/icef2011-60096.

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In the coming years non-road and locomotive diesel engine exhaust gas emissions will become regulated by EPA Tier4 legislation. The stringent emission limits of Tier 4 will require the use of aftertreatment technology currently being used in on-road applications. Based on the potentially large displacements of these engines, the aftertreatment systems will be large and expensive. The flow restriction that is added by the aftertreatment system will result in additional engine pumping work and lower fuel efficiency. The high durability requirements that are demanded of the aftertreatment systems is another factor that needs to be considered. Technologies that reduce complexity, size and cost of the aftertreatment system and minimize incremental fuel consumption are needed. Metal substrate technology offers a number of solutions for the challenges in meeting Tier 4 legislation. The substrates can be used for oxidation catalysts, selective catalytic reduction and slip catalysts depending on what kind of coating is applied to them. The thin wall technology that metal substrates can offer, even at coarse cell densities and lack of required retention mat for system integration provides more open frontal area, leading to lower flow restriction and lower fuel consumption. When designing a modular exhaust system, the shape flexibility will allow for denser packaging of the catalysts. This maximizes the amount of available cross-sectional area, leading to a most compact exhaust system and again better fuel efficiency. Large diameter catalysts can be manufactured in one piece, rather than being joined together from several pieces. A more robust substrate is the outcome.

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Ishak, M. A., I. C. H. Chai, Y. H. Chan, K. E. Nikulainen, J. Laukka et H. S. Hazri. « Thermo-Catalytic Decomposition of Methane to Produce Low-Carbon Hydrogen and Solid Carbon ». Dans SPE Annual Technical Conference and Exhibition. SPE, 2024. http://dx.doi.org/10.2118/220766-ms.

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Abstract The study explores the use of thermo-catalytic decomposition (TCD) of methane to produce hydrogen (H2) and solid carbon. The research focuses on the performance of a proprietary molten metal catalyst in a TCD reactor, evaluating methane conversion efficiency and carbon quality under various operating conditions, including flow rates, pressure, and temperature. The results demonstrate that increasing the temperature from 920°C to 1030°C enhances methane conversion efficiency from 61% to 94%. Catalyst loss was minimal at 0.03%/day, primarily due to manual solid carbon removal. The study also found that higher pressure (from 1 to 12bar) increases H2 yield, from 69% to 85%. The solid carbon produced includes valuable forms such as cryptocrystalline graphite (CG). The TCD process shows an 80% reduction in CO2 intensity compared to traditional steam methane reforming (SMR). This novel approach, termed Turquoise hydrogen production, is economical, modular, and does not require clean water or precious metals, offering potential economic benefits through the sale of high-value carbon materials.

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Rapports d'organisations sur le sujet "Modular catalysis"

Olsen, Daniel, Bryan Hackleman et Rodrigo Bauza Tellechaea. PR-179-16207-R01 Oxidation Catalyst Degradation on a 2-Stroke Lean-Burn NG Engine - Washing. Chantilly, Virginia : Pipeline Research Council International, Inc. (PRCI), mai 2019. http://dx.doi.org/10.55274/r0011586.

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Oxidation catalysts are often utilized to reduce carbon monoxide, formaldehyde, and volatile organic compounds in order to meet emissions regulations for large bore natural gas engines. These catalysts degrade over time and need to be replaced or regenerated to maintain emissions compliance. This work evaluates the effectiveness of catalyst regeneration, or catalyst washing. The evaluation is performed by utilizing field and laboratory slip streams combined with catalyst module performance (reduction efficiency) measurements and catalyst material surface analysis to quantify catalyst poisons.

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Chapman et Toema. PR-266-09211-R01 Physics-Based Characterization of Lambda Sensor from Natural Gas Fueled Engines. Chantilly, Virginia : Pipeline Research Council International, Inc. (PRCI), novembre 2012. http://dx.doi.org/10.55274/r0010022.

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The increasingly strict air emission regulations may require implementing Non-Selective Catalytic Reduction (NSCR) systems as a promising emission control technology for stationary rich burn spark ignition engines. Many recent experimental investigations that used NSCR systems for stationary natural gas fueled engines showed that NSCR systems were unable to consistently control the exhaust emissions level below the compliance limits. Modeling of NSCR components to better understand, and then exploit, the underlying physical processes that occur in the lambda sensor and the catalyst media is now considered an essential step toward improving NSCR system performance. This report focuses on modeling the lambda sensor that provides feedback to the air-to-fuel ratio controller. Correct interpretation of the sensor output signal is necessary to achieve consistently low emissions level. The goal of this modeling study is to improve the understanding of the physical processes that occur within the sensor, investigate the cross-sensitivity of various exhaust gas species on the sensor performance, and finally this model serves as a tool to improve NSCR control strategies. This model simulates the output from a planar switch type lambda sensor. The model consists of three modules. The first module models the multi-component mass transport through the sensor protective layer. The second module includes all the surface catalytic reactions that take place on the sensor platinum electrodes. The third module is responsible for simulating the reactions that occur on the electrolyte material and determine the sensor output voltage.

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Molter, Trent. Electrolyzer Integrated Modular Nano-Array Monolithic Catalytic Reactors. Office of Scientific and Technical Information (OSTI), juin 2024. http://dx.doi.org/10.2172/2377280.

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Wang, Zhichao, Pahola T. Benavides, Jennifer B. Dunn et Donald C. Cronauer. Development of GREET Catalyst Module. Office of Scientific and Technical Information (OSTI), septembre 2015. http://dx.doi.org/10.2172/1224972.

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Wang, Zhichao, Jennifer B. Dunn et Donald C. Cronauer. Development of GREET Catalyst Module. Office of Scientific and Technical Information (OSTI), septembre 2014. http://dx.doi.org/10.2172/1172041.

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Hahn, Michael G. Dissecting the functional significance of non-catalytic carbohydrate binding modules in the deconstruction of plant cell walls. Office of Scientific and Technical Information (OSTI), mars 2017. http://dx.doi.org/10.2172/1346935.

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Veloso, Rita Carvalho, Catarina Dias, Andrea Resende Souza, Joana Maia, Nuno M. M. Ramos et João Ventura. Improving the optical properties of finishing coatings for façade systems. Department of the Built Environment, 2023. http://dx.doi.org/10.54337/aau541592743.

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The need to improve energy efficiency of the building stock has led to a continuous increase in the implementation of exterior thermal insulation systems, such as ETICS. Progressively, these systems are being applied with darker colours, increasing the concern for hygrothermal behaviour and durability. Despite the significant developed studies, very few reports regarding their optical properties are available. The optical and catalytic capacity turns nanomaterials into excellent candidates for use in finishing coatings with high solar reflectance with dark colours without affecting the aesthetic characteristics, thus improving the durability of such coatings. Our study targeted the development of innovative envelope systems by increasing their solar reflectance through new finishing coatings formulations with the inclusion of nanoparticles. For that, it is necessary to develop and optimize nanoparticles formulations to achieve a high near-infrared reflectance. Here, we studied how the incorporation of reflective nanomaterials influence the optical behaviour of a black colourant for a finishing coating, varying the concentration in the coating from 0 to 20%. Such optical performance was experimentally evaluated through spectral reflectance calculations using a modular spectrophotometer, which allowed an understanding of the relation between these properties and the morphological and structural characteristics of the nanoparticles. The results from such studies can help formulate new finishing coatings with increased near-infrared reflectance of buildings façades, using, for instance, more than one type of nanoparticle.

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Sessa, Guido, et Gregory Martin. MAP kinase cascades activated by SlMAPKKKε and their involvement in tomato resistance to bacterial pathogens. United States Department of Agriculture, janvier 2012. http://dx.doi.org/10.32747/2012.7699834.bard.

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The research problem: Pseudomonas syringae pv. tomato (Pst) and Xanthomonas campestrispv. vesicatoria (Xcv) are the causal agents of tomato bacterial speck and spot diseases, respectively. These pathogens colonize the aerial parts of the plant and cause economically important losses to tomato yield worldwide. Control of speck and spot diseases by cultural practices or chemicals is not effective and genetic sources of resistance are very limited. In previous research supported by BARD, by gene expression profiling we identified signaling components involved in resistance to Xcvstrains. Follow up experiments revealed that a tomato gene encoding a MAP kinase kinase kinase (MAPKKKe) is required for resistance to Xcvand Pststrains. Goals: Central goal of this research was to investigate the molecular mechanisms by which MAPKKKεand associated MAP kinase cascades regulate host resistance. Specific objectives were to: 1. Determine whether MAPKKKεplays a broad role in defense signaling in plants; 2. Identify components of MAP kinase cascades acting downstream of MAPKKKε; 3. Determine the role of phosphorylation-related events in the function of MAPKKKε; 4. Isolate proteins directly activated by MAPKKKε-associatedMAPK modules. Our main achievements during this research program are in the following major areas: 1. Characterization of MAPKKKεas a positive regulator of cell death and dissection of downstream MAP kinase cascades (Melech-Bonfil et al., 2010; Melech-Bonfil and Sessa, 2011). The MAPKKKεgene was found to be required for tomato resistance to Xcvand Pstbacterial strains and for hypersensitive response cell death triggered by different R gene/effector gene pairs. In addition, overexpression analysis demonstrated that MAPKKKεis a positive regulator of cell death, whose activity depends on an intact kinase catalytic domain. Epistatic experiments delineated a signaling cascade downstream of MAPKKKεand identified SIPKK as a negative regulator of MAPKKKε-mediated cell death. Finally, genes encoding MAP kinase components downstream of MAPKKKεwere shown to contribute to tomato resistance to Xcv. 2. Identification of tomato proteins that interact with MAPKKKεand play a role in plant immunity (Oh et al., 2011). We identified proteins that interact with MAPKKKε. Among them, the 14-3-3 protein TFT7 was required for cell death mediated by several R proteins. In addition, TFT7 interacted with the MAPKK SlMKK2 and formed homodimersin vivo. Thus, TFT7 is proposed to recruit SlMKK2 and MAPKKK client proteins for efficient signal transfer. 3. Development of a chemical genetic approach to identify substrates of MAPKKKε-activated MAP kinase cascades (Salomon et al., 2009, 2011). This approach is based on engineering the kinase of interest to accept unnatural ATP analogs. For its implementation to identify substrates of MAPKKKε-activated MAP kinase modules, we sensitized the tomato MAP kinase SlMPK3 to ATP analogs and verified its ability to use them as phosphodonors. By using the sensitized SlMPK3 and radiolabeled N6(benzyl)ATP it should be possible to tag direct substrates of this kinase. 4. Development of methods to study immunity triggered by pathogen-associated molecular patterns (PAMPs) in tomato and N. benthamiana plants (Kim et al., 2009; Nguyen et al. 2010). We developed protocols for measuring various PTI-associatedphenotypes, including bacterial populations after pretreatment of leaves with PAMPs, induction of reporter genes, callose deposition at the cell wall, activation of MAP kinases, and a luciferase-based reporter system for use in protoplasts. Scientific and agricultural significance: Our research activities discovered and characterized a signal transduction pathway mediating plant immunity to bacterial pathogens. Increased understanding of molecular mechanisms of immunity will allow them to be manipulated by both molecular breeding and genetic engineering to produce plants with enhanced natural defense against disease. In addition, we successfully developed new biochemical and molecular methods that can be implemented in the study of plant immunity and other aspects of plant biology.

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