Bibliografie tematiche / Native hydrogen

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Letteratura scientifica selezionata sul tema "Native hydrogen"

Autore: Grafiati

Pubblicato: 5 ottobre 2024

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Articoli di riviste sul tema "Native hydrogen"

Scott, Erin. "Exploring for native hydrogen". Nature Reviews Earth & Environment 2, n. 9 (27 agosto 2021): 589. http://dx.doi.org/10.1038/s43017-021-00215-2.

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Garrido, Claudia A., Michel Vargas e Jose F. Alvarez-Barreto. "Auto-Cross-Linking Hydrogels of Hydrogen Peroxide-Oxidized Pectin and Gelatin for Applications in Controlled Drug Delivery". International Journal of Polymer Science 2019 (24 febbraio 2019): 1–11. http://dx.doi.org/10.1155/2019/9423565.

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Pectin-based hydrogels for biomedical applications have attracted recent attention due to their low cost, large availability of the materials, and high levels of biocompatibility. Specifically, periodate-oxidized pectin has been combined with chitosan and gelatin to form different structures. However, hydrogen peroxide-mediated oxidation of pectin has not been studied for this application; furthermore, there is little information on the effect of the degree of oxidation on hydrogel characteristics nor has the feasibility of these systems as controlled drug delivery matrices been explored. Thus, the present work proposes to study the properties of gelatin-peroxide-oxidized pectin hydrogels as drug delivery systems in wound dressing applications. Combinations of pectin at different degrees of oxidation (high, low, and native pectin) and gelatin were analyzed and tested by swelling properties, reswelling from xerogel and aerogel forms, SEM, FTIR, and drug release. It was determined that hydrogels that contained oxidized pectin had improved swelling ratios and stability, at 32°C, compared to those with native pectin and only gelatin. The porosity of the oxidized pectin hydrogels allowed to have sustained and high release rates, which would make them an attractive alternative for wound dressings.

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LeMaster, David M., Janet S. Anderson e Griselda Hernández. "Role of Native-State Structure in Rubredoxin Native-State Hydrogen Exchange†". Biochemistry 45, n. 33 (agosto 2006): 9956–63. http://dx.doi.org/10.1021/bi0605540.

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Lee, In-Ho, e Seung-Yeon Kim. "Dynamic Folding Pathway Models of the Trp-Cage Protein". BioMed Research International 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/973867.

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Using action-derived molecular dynamics (ADMD), we study the dynamic folding pathway models of the Trp-cage protein by providing its sequential conformational changes from its initial disordered structure to the final native structure at atomic details. We find that the numbers of native contacts and native hydrogen bonds are highly correlated, implying that the native structure of Trp-cage is achieved through the concurrent formations of native contacts and native hydrogen bonds. In early stage, an unfolded state appears with partially formed native contacts (~40%) and native hydrogen bonds (~30%). Afterward, the folding is initiated by the contact of the side chain of Tyr3 with that of Trp6, together with the formation of the N-terminalα-helix. Then, the C-terminal polyproline structure docks onto the Trp6 and Tyr3 rings, resulting in the formations of the hydrophobic core of Trp-cage and its near-native state. Finally, the slow adjustment processes of the near-native states into the native structure are dominant in later stage. The ADMD results are in agreement with those of the experimental folding studies on Trp-cage and consistent with most of other computational studies.

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Amini, M. N., R. Saniz, D. Lamoen e B. Partoens. "Hydrogen impurities and native defects in CdO". Journal of Applied Physics 110, n. 6 (15 settembre 2011): 063521. http://dx.doi.org/10.1063/1.3641971.

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Bai, Y., T. Sosnick, L. Mayne e S. Englander. "Protein folding intermediates: native-state hydrogen exchange". Science 269, n. 5221 (14 luglio 1995): 192–97. http://dx.doi.org/10.1126/science.7618079.

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Liu, Wei, Yong Cui, Xu Du, Zhe Zhang, Zisheng Chao e Yulin Deng. "High efficiency hydrogen evolution from native biomass electrolysis". Energy & Environmental Science 9, n. 2 (2016): 467–72. http://dx.doi.org/10.1039/c5ee03019f.

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Van de Walle, Chris G. "Interactions of hydrogen with native defects in GaN". Physical Review B 56, n. 16 (15 ottobre 1997): R10020—R10023. http://dx.doi.org/10.1103/physrevb.56.r10020.

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Stanzione, Antonella, Alessandro Polini, Velia La Pesa, Alessandro Romano, Angelo Quattrini, Giuseppe Gigli, Lorenzo Moroni e Francesca Gervaso. "Development of Injectable Thermosensitive Chitosan-Based Hydrogels for Cell Encapsulation". Applied Sciences 10, n. 18 (19 settembre 2020): 6550. http://dx.doi.org/10.3390/app10186550.

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The three-dimensional complexity of the native extracellular matrix (ECM) suggests switching from 2D to 3D culture systems for providing the cells with an architecture more similar to the physiological environment. Reproducing the three-dimensionality in vitro can guarantee beneficial effects in terms of cell growth, adhesion, proliferation, and/or their differentiation. Hydrogels have the same tailorable physico-chemical and biological characteristics as ECM materials. In this study, we propose a thermoresponsive chitosan-based hydrogel that gels thanks to the addition of organic and inorganic salt solutions (beta-glycerolphosphate and sodium hydrogen carbonate) and is suitable for cell encapsulation allowing obtaining 3D culture systems. Physico-chemical analyses showed that the hydrogel formulations jellify at physiological conditions (37 °C, pH 7.4), are stable in vitro up to three weeks, have high swelling ratios and mechanical stiffness suitable for cellular encapsulation. Moreover, preliminary biological tests underlined the pronounced biocompatibility of the system. Therefore, these chitosan-based hydrogels are proposed as valid biomaterials for cell encapsulation.

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Gaucher, Eric C. "New Perspectives in the Industrial Exploration for Native Hydrogen". Elements 16, n. 1 (1 febbraio 2020): 8–9. http://dx.doi.org/10.2138/gselements.16.1.8.

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Tesi sul tema "Native hydrogen"

McKee, David. "Nuclear Transparency and Single Particle Spectral Functions from Quasielastic A(e,e'p) Reactions up to Q2=8.1 GeV2". Washington, D.C : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Energy Research ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2003. http://www.osti.gov/servlets/purl/824828-CBQre3/native/.

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Thesis (Ph.D.); Submitted to New Mexico State Univ., Las Cruces, NM (US); 1 May 2003.
Published through the Information Bridge: DOE Scientific and Technical Information. "JLAB-PHY-03-22" "DOE/ER/40150-2731" David McKee. 05/01/2003. Report is also available in paper and microfiche from NTIS.

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Carnahan, Brian. "Strangeness Photoproduction in the {gamma}p {yields} K{sup 0} {Sigma}{sup +} Reaction". Washington, D.C : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Energy Research ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2003. http://www.osti.gov/servlets/purl/824935-CL5ICZ/native/.

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Thesis (Ph.D.); Submitted to the Catholic Univ. of America, Washington, DC (US); 1 May 2003.
Published through the Information Bridge: DOE Scientific and Technical Information. "JLAB-PHY-03-40" "DOE/ER/40150-2764" Brian Carnahan. 05/01/2003. Report is also available in paper and microfiche from NTIS.

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Terral, Guillaume. "Apports de l'échange hydrogène/deutérium couplé à la spectrométrie de masse en protéomique structurale pour la caractérisation de complexes multi-protéiques". Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAF019/document.

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Ce travail de thèse porte sur développement de méthodes en spectrométrie de masse structurale pour l’analyse de protéines recombinantes et de leurs complexes associés. L’objectif central s’est porté sur des développements méthodologiques en échange hydrogène/deutérium couplé à la spectrométrie de masse (HDX-MS). Les techniques biophysiques de caractérisation structurale à haute résolution comme la cristallographie ou la RMN se heurtent régulièrement à des problèmes de productions de cristaux, de taille de complexes analysables ou encore de quantité de matériel nécessaire importante. Le développement de méthodes spécifiques HDX-MS a permis de réaliser une caractérisation structurale de systèmes protéiques variés, et réfractaires aux approches haute résolution. La combinaison de cette approche à différents outils de MS structurale est aussi illustrée, et montre tout son intérêt pour l’obtention d’informations à résolution augmentée
This thesis work focuses on development of structural mass spectrometry methods for the analysis of recombinant proteins and their associated complex. The central objective has focused on the development of hydrogen/deuterium exchange coupled to mass spectrometry approaches (HDX-MS). The high resolution biophysical techniques for structural characterization such as crystallography or NMR regularly face problems of crystal productions, size analyzable complex or quantity of material required. The development of specific HDX-MS methods allowed the characterization of various, and refractory protein systems to high resolution approaches. The combination of this approach with complementary structural MS tools is also illustrated, and shows its interest to obtain increased resolution information

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Kamara, Konakpo Parfait. "Stratégies d’utilisation du bio hydrogène pour la technologie PEMFC : utilisation directe". Electronic Thesis or Diss., Université Grenoble Alpes, 2024. http://www.theses.fr/2024GRALI037.

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La France dans le but de décarboner son mix énergétique et baisser ses émissions de CO2 a décidé d’investir massivement dans la production décarbonée d’hydrogène comme vecteur d’énergie pour des applications de mobilités ou stationnaires[1]. Sur le million de tonnes d’hydrogène produit en France, 96 % est produit par vaporeformage d’hydrocarbures. La stratégie Française vise à développer la filière hydrogène en investissant dans l’installation d’électrolyseurs. De plus les dernières découvertes d’énormes gisements d’hydrogène naturel (46 millions de tonnes d’hydrogène en Lorraine) crée l’enthousiasme et agrandi le champ des perspectives. [2]. Une autre filière de production d’hydrogène décarboné dont on parle le moins est la filière biologique qui présente un grand potentiel de diversifications des voies de productions. L’hydrogène issu de ces filières pose le problème de sa qualité pour une application dans la mobilité ou le stationnaire dans des systèmes de pile à combustible.L’objet de ces travaux de thèse est de définir des stratégies pour l’utilisation du bio hydrogène ou hydrogène naturel par la technologie de pile à combustible à membrane échangeuse de protons (PEMFC) et en passant par les étapes de production de l’hydrogène jusqu’à sa conversion électrochimique.La première partie a consisté à étudier l’impact des impuretés ou diluants (N2, Ar, He, CH4, CO2) contenus dans l’hydrogène issu des filières biologique et natif dans une demi-cellule (cellule de diffusion de gaz, GDE). Ensuite cette étude a été étendue à une mono cellule de pile à combustible à membrane échangeuse de protons. Enfin un réacteur biologique à échelle du laboratoire a permis de produire de l’hydrogène à partir de sources organiques par photo fermentation (PF) qui a ensuite été testé en GDE. Plusieurs techniques de caractérisations électrochimiques et physicochimiques comme la voltammétrie cyclique, la chrono amperommétrie, la mesure de surface électro-active par CO stripping, la microscopie électronique à balayage et à transmission, la chromatographie ionique etc…ont permis d’évaluer les performances de la PEMFC alimenté par du bio hydrogène ainsi que son impact sur les éléments d’une pile à combustible.Les résultats de l’activité des électrodes pour la réaction d’oxydation de l’hydrogène en GDE ont mis évidence des effets de limitations par le transport de matières pour l’ensemble mélange, avec des comportements particuliers observés pour le mélange à l’azote, et les mélanges au méthane et au dioxyde de carbone qui en plus de la dilution ont un effet d’empoisonnement au monoxyde de carbone de l’électrode.Ensuite, les tests en mono cellule alimenté par les mélanges H2/Ar, H2/N2 et H2/CO2 à 30 et 40 % volumique en H2 pour une application stationnaire ont révélé des pertes de performances plus importantes pour le mélange au dioxyde carbone, les mélanges à l’argon et à l’azote ont des performances quasiment équivalentes. Ces pertes de performances sont dues à des pertes de surfaces électro actives.Enfin la production de bio hydrogène par PF a montré que le choix de la biomasse, le prétraitement et la souche bactérienne influençaient la qualité du biogaz produit et les performances électrochimiques obtenues à partir de ce dernier sans étapes de purification.Références[1] « Présentation de la stratégie nationale pour le développement de l’hydrogène décarboné en France ». Consulté le: 11 janvier 2024. [En ligne]. Disponible sur: https://www.economie.gouv.fr/presentation-strategie-nationale-developpement-hydrogene-decarbone-france[2] « Le plus gros gisement d’hydrogène naturel du monde vient d’être découvert en France », SudOuest.fr. Consulté le: 11 janvier 2024. [En ligne]. Disponible sur: https://www.sudouest.fr/economie/energie/le-plus-gros-gisement-d-hydrogene-naturel-du-monde-vient-d-etre-decouvert-en-france-17826239.php
With the aim of decarbonizing its energy mix and lowering its CO2 emissions, France has decided to invest massively in the decarbonized production of hydrogen as an energy carrier for mobility and stationary applications [1]. Of the one million ton of hydrogen produced in France, 96% is produced by steam reforming of hydrocarbons. France's strategy is to develop the hydrogen sector by investing in the installation of electrolyzers. What's more, the latest discoveries of huge deposits of natural hydrogen (46 million tons of hydrogen in Lorraine) are creating enthusiasm and expanding the field of prospects. [2]. Another decarbonated hydrogen production sector that is less talked about is the biological sector, which offers great potential for diversifying production routes. Hydrogen from these sources raises the question of its quality for use in mobility or stationary fuel cell systems.The aim of this thesis is to define strategies for the use of bio-hydrogen or natural hydrogen using proton exchange membrane fuel cell (PEMFC) technology, from hydrogen production to electrochemical conversion.The first part consisted in studying the impact of impurities or diluents (N2, Ar, He, CH4, CO2) contained in hydrogen from biological and native processes in a half-cell (gas diffusion electrode, GDE). This study was then extended to a single-cell proton exchange membrane fuel cell. Finally, a laboratory-scale biological reactor was used to produce hydrogen from organic sources by photo fermentation (PF), which was then tested in a GDE. Several electrochemical and physicochemical characterization techniques, such as cyclic voltammetry, chrono amperometry, CO stripping for electroactive surface measurement, scanning and transmission electron microscopy, ion chromatography, etc., were used to assess the performance of the PEMFC fed by bio-hydrogen, and its impact on fuel cell components.The results of the electrode activity for the hydrogen oxidation reaction in GDE revealed mass-transport limitation effects for the mixtures, with a particular behavior observed for the nitrogen mixture, and the methane and carbon dioxide mixtures, which in addition to dilution have a carbon monoxide poisoning effect on the electrode.Next, single-cell tests using H2/Ar, H2/N2 and H2/CO2 mixtures at 30 and 40% H2 by volume for stationary applications revealed greater performance losses for the carbon dioxide mixture, while the argon and nitrogen mixtures performed almost equally well. These performance losses are due to electroactive surface losses.Finally, the production of biohydrogen by PF showed that the choice of biomass, pre-treatment and bacterial strain influenced the quality of the biogas produced and the electrochemical performances obtained from it without purification steps.References[1] « Présentation de la stratégie nationale pour le développement de l’hydrogène décarboné en France ». Consulté le: 11 janvier 2024. [En ligne]. Disponible sur: https://www.economie.gouv.fr/presentation-strategie-nationale-developpement-hydrogene-decarbone-france[2] « Le plus gros gisement d’hydrogène naturel du monde vient d’être découvert en France », SudOuest.fr. Consulté le: 11 janvier 2024. [En ligne]. Disponible sur: https://www.sudouest.fr/economie/energie/le-plus-gros-gisement-d-hydrogene-naturel-du-monde-vient-d-etre-decouvert-en-france-17826239.php

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Bourguet, Maxime. "Développements méthodologiques en spectrométrie de masse structurale pour la caractérisation de complexes biologiques multiprotéiques". Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAF013.

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Ce travail de thèse porte sur le développement de méthodes de spectrométrie de masse (MS) structurale pour la caractérisation de systèmes protéiques complexes, souvent réfractaires aux approches biophysiques classiques. Dans ce contexte, les développements entrepris furent notamment focalisés sur la caractérisation de complexes impliqués dans la biogénèse des ribosomes et dans la régulation transcriptionnelle, fonctions cellulaires essentielles pouvant être liées à de nombreuses pathologies humaines dont certains cancers. Ainsi, les approches par MS native, pontage chimique et d’HDX-MS ont permis de renseigner sur la connectivité, les proximités spatiales ou encore la dynamique conformationnelle retrouvées au sein des complexes étudiés. Parmi ces techniques, l’HDX-MS permet une approche comparative basée sur les mesures d’incorporations en deutérium renseignant sur la dynamique conformationnelle d’une protéine sous différents états. Aussi, la combinaison d’approches de MS structurale a permis d’approfondir la caractérisation des systèmes complexes étudiés, démontrant ainsi l’intérêt d’une approche intégrative dans ce contexte
This PhD thesis focuses on developing methods in structural mass spectrometry (MS) to characterize complex protein systems, given their size and their heterogeneity, frequently inaccessible by classical biophysic approaches. In this context, methodological developments have particularly focused on the characterization of protein complexes involved in ribosomes biogenesis and transcriptional regulation. These fundamental cellular processes are related to numerous diseases such as cancers and genetic diseases. Thus native MS, crosslink, and hydrogen/deuterium exchange coupled to MS (HDX-MS) allowed gaining insights about the stoechiometry, spatial proximities and conformational dynamics of studied systems. Among these approaches, HDX-MS enables a comparative approach based on deuterium incorporation measurements giving information about the conformational dynamics of labeled proteins in various experimental conditions. Finally, the combination of structural approaches enables to deeply characterize complex protein systems, highlighting the advantages of an integrative approach in this context

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Castel, Jérôme. "Developpements en spectrométrie de masse structurale pour la caratérisation de protéines d'intérêt thérapeutique". Electronic Thesis or Diss., Strasbourg, 2024. http://www.theses.fr/2024STRAF003.

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Ce travail de thèse porte sur des développements méthodologiques en spectrométrie de masse (MS) structurale, principalement par échange hydrogène/deutérium couplé à la MS (HDX-MS), en MS native couplée ou non à la mobilité ionique (IM-MS) et plus récemment en photométrie de masse, pour la caractérisation de différentes protéines d’intérêt thérapeutique. Ce travail a notamment permis de montrer l’apport d’une combinaison d’approches en MS structurale pour la caractérisation approfondie des protéines membranaires, de l’analyse des protéines entières jusqu’à leur dynamique conformationnelle. La mise en place de nouvelles stratégies analytiques en IM-MS et en HDX-MS a également pu être évaluée pour la caractérisation structurale fine d’anticorps thérapeutiques. Enfin, l’intérêt de l’approche HDX-MS a été illustré pour le screening conformationnel et dynamique de ligands dans le cadre de l’étude d’interactions protéine/ligand impliquant des récepteurs nucléaires
This PhD work focuses on methodological developments in structural mass spectrometry (MS), especially by hydrogen/deuterium exchange coupled to MS (HDX-MS), by native MS coupled or not to ion mobility (IM-MS) and more recently mass photometry, for the characterization of various proteins of therapeutic interest. In particular, this work has demonstrated the contribution of a combination of structural MS approaches to the in-depth characterization of membrane proteins, from the analysis of intact proteins to their conformational dynamics. The implementation of new analytical strategies in IM-MS and HDX-MS has also been evaluated for the detailed structural characterization of therapeutic antibodies. Finally, the benefits of HDX-MS approach was illustrated for the conformational and dynamic screening of ligands in the context of the study of protein/ligand interactions involving nuclear receptors

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Bleijlevens, Boris. "Activation and sensing of hydrogen in nature". [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2002. http://dare.uva.nl/document/61349.

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Dua, Rupak. "Enhanced Anchorage of Tissue-Engineered Cartilage Using an Osteoinductive Approach". FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/context/etd/article/2559/type/native/viewcontent.

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Articular cartilage injuries occur frequently in the knee joint. Several methods have been implemented clinically, to treat osteochondral defects but none have been able to produce a long term, durable solution. Photopolymerizable cartilage tissue engineering approaches appear promising; however, fundamentally, forming a stable interface between the tissue engineered cartilage and native tissue, mainly subchondral bone and native cartilage, remains a major challenge. The overall objective of this research is to find a solution for the current problem of dislodgment of tissue engineered cartilage at the defect site for the treatment of degraded cartilage that has been caused due to knee injuries or because of mild to moderate level of osteoarthritis. For this, an in-vitro model was created to analyze the integration of tissue engineered cartilage with the bone, healthy and diseased cartilage over time. We investigated the utility of hydroxyapatite (HA) nanoparticles to promote controlled bone-growth across the bone-cartilage interface in an in vitro engineered tissue model system using bone marrow derived stem cells. We also investigated the application of HA nanoparticles to promote enhance integration between tissue engineered cartilage and native cartilage both in healthy and diseased states. Samples incorporated with HA demonstrated significantly higher interfacial shear strength (at the junction between engineered cartilage and engineered bone and also with diseased cartilage) compared to the constructs without HA (p < 0.05), after 28 days of culture. These findings indicate that the incorporation of HA nanoparticles permits more stable anchorage of the injectable hydrogel-based engineered cartilage construct via augmented integration between bone and cartilage.

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Fernandes, Wren Austin. "Synthesis of an erodible biomimetic hydrogel for drug delivery using native chemical ligation". Thesis, Queensland University of Technology, 2012. https://eprints.qut.edu.au/59502/1/Wren_Fernandes_Thesis.pdf.

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Hydrogels are hydrophilic, three dimensional polymers that imbibe large quantities of water while remaining insoluble in aqueous solutions due to chemical or physical cross-linking. The polymers swell in water or biological fluids, immobilizing the bioactive agent, leading to drug release in a well-defined specific manner. Thus the hydrogels’ elastic properties, swellability and biocompatibility make them excellent formulations for drug delivery. Currently, many drug potencies and therapeutic effects are limited or otherwise reduced because of the partial degradation that occurs before the administered drug reaches the desired site of action. On the other hand, sustained release medications release drugs continually, rather than providing relief of symptoms and protection solely when necessary. In fact, it would be much better if drugs could be administered in a manner that precisely matches physiological needs at desired times and at the desired site (site specific targeting). There is therefore an unmet need to develop controlled drug delivery systems especially for delivery of peptide and protein bound drugs. The purpose of this project is to produce hydrogels for structural drug delivery and time-dependent sustained release of drugs (bioactive agents). We use an innovative polymerisation strategy based on native chemical ligation (NCL) to covalently cross-link polymers to form hydrogels. When mixed in aqueous solution, four armed (polyethylene glycol) amine (PEG-4A) end functionalised with thioester and four branched Nterminal cysteine peptide dendrimers spontaneously conjugated to produce biomimetic hydrogels. These hydrogels showed superior resistance to shear stress compared to an equivalent PEG macromonomer system and were shown to be proteolytically degradable with concomitant release of a model payload molecule. This is the first report of a peptide dendrimers/PEG macromonomer approach to hydrogel production and opens up the prospect of facile hydrogel synthesis together with tailored payload release.

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Yip, D. C. F. "Nature and control of water in synthetic hydrogels". Thesis, University of Salford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381735.

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Libri sul tema "Native hydrogen"

S, Donovan Lisa, Coastal Marine Institute (Baton Rouge, La.), Louisiana State University (Baton Rouge, La.). Dept. of Oceanography and Coastal Sciences e United States. Minerals Management Service. Gulf of Mexico OCS Region, a cura di. Survival of a hydrogen-utilizing bacterium when introduced into native and foreign environments. New Orleans: U.S. Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, 2001.

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S, Donovan Lisa, Coastal Marine Institute (Baton Rouge, La.), Louisiana State University (Baton Rouge, La.). Dept. of Oceanography and Coastal Sciences. e United States. Minerals Management Service. Gulf of Mexico OCS Region., a cura di. Survival of a hydrogen-utilizing bacterium when introduced into native and foreign environments. New Orleans: U.S. Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, 2001.

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Holland, Geoffrey B. The hydrogen age: Empowering a clean-energy future. Layton, Utah: Gibbs Smith, 2007.

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Survival of a hydrogen-utilizing bacterium when introduced into native and foreign environments. New Orleans: U.S. Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, 2001.

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Holland, Geoffrey, e James Provenzano. Hydrogen Age, The. Gibbs Smith, Publisher, 2007.

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Nweke, Christian O. Sustainable Hydrogen Fuel Economy........................................................................................................................: Solution to Climate Change. T. Fielding-Lowe Company, 2022.

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Hernández, Griselda, e David M. LeMaster. "NMR Analysis of Native-State Protein Conformational Flexibility by Hydrogen Exchange". In Methods in Molecular Biology, 285–310. Totowa, NJ: Humana Press, 2008. http://dx.doi.org/10.1007/978-1-59745-367-7_12.

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Isogai, A., A. Ishizu, J. Nakano e Rajai H. Atalla. "Intra- and Intermolecular Hydrogen Bonds in Native, Mercerized, and Regenerated Celluloses". In ACS Symposium Series, 292–301. Washington, DC: American Chemical Society, 1987. http://dx.doi.org/10.1021/bk-1987-0340.ch017.

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Yarn, Kao Feng, Y. L. Lin, M. C. Chure, K. K. Wu e S. C. Chang. "Pd/Oxide/InGaP MOS Schottky Hydrogen Sensor with Native Thin Oxide". In Solid State Phenomena, 627–30. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/3-908451-30-2.627.

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Hirose, Masataka, Masaru Takakura, Tatsuhiro Yasaka e Seiichi Miyazaki. "Native Oxide Growth and Hydrogen Bonding Features on Chemically Cleaned Silicon Surfaces". In The Physics and Chemistry of SiO2 and the Si-SiO2 Interface 2, 177–86. Boston, MA: Springer US, 1993. http://dx.doi.org/10.1007/978-1-4899-1588-7_19.

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Malhotra, Pooja, e Jayant B. Udgaonkar. "Native State Hydrogen Exchange-Mass Spectrometry Methods to Probe Protein Folding and Unfolding". In Protein Folding, 143–59. New York, NY: Springer US, 2021. http://dx.doi.org/10.1007/978-1-0716-1716-8_8.

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Riemer, Jan, e Helmut Sies. "Mitochondrial Hydrogen Peroxide Dynamics". In The Dynamic Nature of Mitochondria, 89–95. Boca Raton: CRC Press, 2024. http://dx.doi.org/10.1201/9781003221180-8.

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Wang, Jian, Yang Gao, Shijie Sun e Lei Shi. "Safety Technologies and Challenges of Hydrogen-Powered Rail Transport". In Proceedings of the 10th Hydrogen Technology Convention, Volume 1, 100–107. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-99-8631-6_11.

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AbstractAs one of the many energy alternatives, the interest in hydrogen-powered rail transport is gradually increasing worldwide, and some railway vehicles powered by hydrogen are currently in operation or undergoing experimental projects. However, due to the unsafe and unstable nature of hydrogen energy, hydrogen has potential leakage and explosion hazards in all rail transport applications. This paper summarizes the main application technologies of hydrogen safety in light of the research progress and unsafe factors in the process in the field of hydrogen-powered rail transport in various countries, at the same time clarifies the development challenges and difficulties of hydrogen-powered rail transport in the future, and makes suggestions for the development of hydrogen-powered rail transport safety in China.

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Nogaj, Bolesław. "Hydrogen Bond Nature in Solids Based on Nuclear Quadrupole Resonance Spectroscopy Studies". In Hydrogen Bond Networks, 261–80. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-015-8332-9_27.

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Sinha, Nilima, e Srimanta Pakhira. "Hydrogen: A Future Chemical Fuel". In Materials Horizons: From Nature to Nanomaterials, 1–30. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-7285-9_1.

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Furukawa, Hidemitsu, e Jian Ping Gong. "Tough Hydrogel - Learn from Nature". In Artificial Muscle Actuators using Electroactive Polymers, 40–45. Stafa: Trans Tech Publications Ltd., 2008. http://dx.doi.org/10.4028/3-908158-18-4.40.

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Atti di convegni sul tema "Native hydrogen"

Sadiek, Ibrahim, Norbert Lang, Adam J. Fleisher e Jean-Pierre van Helden. "Precision Frequency Comb Spectroscopy of Reactive Molecular Plasmas". In CLEO: Science and Innovations, SF2F.6. Washington, D.C.: Optica Publishing Group, 2024. http://dx.doi.org/10.1364/cleo_si.2024.sf2f.6.

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Using precision frequency comb spectroscopy, we study low-pressure molecular plasmas containing nitrogen, hydrogen, and a carbon source. We obtain precise quantum-state-resolved knowledge of plasma-generated molecules, providing insights into the non-thermal nature of plasma chemical processes.

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Zamora, G., R. Loma, A. Monge, M. Masini, A. Vayssaire e A. Olaiz. "Can Native Hydrogen be Part of the Energy Transition?" In 83rd EAGE Annual Conference & Exhibition. European Association of Geoscientists & Engineers, 2022. http://dx.doi.org/10.3997/2214-4609.202210921.

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Ranaee, E., F. Inzoli, M. Riva e A. Guadagnini. "Appraisal of Native Hydrogen Accumulation in Geological Formations under Uncertainty". In SPE Europe Energy Conference and Exhibition. SPE, 2024. http://dx.doi.org/10.2118/220092-ms.

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Abstract Objectives/Scope: A key issue related to potential accumulation of native hydrogen (H2) in geological formations is the risk of hydrogen loss due to conversion to other chemical species such as methane (CH4). Our study tries to quantify how uncertainties linked to carbonate-clay reactions (CCR) reflect in evaluation of the geogenic methane generation and the associated losses of native H2. Methods, Procedures, Process: We rely on a modeling workflow developed by Ceriotti et al. (2017) for evaluating geogenic carbon dioxide, CO2, generation through CCR in sedimentary basins. As a showcase, we consider a one-dimensional (vertical) model patterned after a typical sedimentary compaction setting. Such a model provides the dynamics of porosity, temperature, and pressure along the vertical direction. Outputs of the compaction model are viewed as deterministic quantities. We then consider a given mineral composition and focus on the quantification of the parametric uncertainties associated with CCR. This is reflected in the uncertainty related to the values of thermodynamic equilibrium constants of the species involved in CCR and is then propagated onto the ensuing estimated CO2 release. Underground trapping of native H2 is conceptualized upon considering the subsurface as a natural chemical reactor that consumes a mixture of H2 (generated from serpentinization of ultramafic rocks) and CO2 (from CCR) yielding a mixture of H2/CO2/CH4. Our analysis considers that (a) complete mixing of the chemical species is attained and (b) geochemical reactions can be evaluated under thermodynamic equilibrium conditions. We then perform a modelling study framed in a stochastic context and relying on a numerical Monte Carlo framework. The latter is aimed at quantifying uncertainty associated with methane production following geogenic hydrogen and carbon dioxide generation. Our results are tied to (i) shallow, (ii) intermediate-depth, and (ii) deep reservoirs. Due to its preliminary nature, the study considers uncertainty solely in the CCR process as well as accumulation reservoir depth/pressure/temperature conditions. Results, Observations, Conclusions: Our results suggest that accumulation of H2 in geological formations entails the risk of hydrogen loss due to conversion to CH4 by methanogenesis. They also suggest that deep geological formations (characterized by high temperature and pressure conditions) tend to limit hydrogen loss due to methanogenesis reactions. Thus, exploration of native H2 accumulations could target geological formations where the residing gas has low CO2 concentrations and where the mineralogical composition of reservoir rocks contains low amounts of carbon-bearing minerals. Novel/Additive Information: We provide a quantification of native hydrogen losses with the explicit inclusion of a stochastic assessment of some uncertainties linked to the geogenic generation of CO2.

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SUGIYAMA, Kazuhisa, Takayuki IGARASHI, Kazunori MORIKI, Yoshikatsu NAGASAWA, Takayuki AOYAMA, Rinshi SUGINO, Takashi ITO e Takeo HATTORI. "Silicon-Hydrogen Bonds in Native Oxides Formed during Wet Chemical Treatments". In 1990 International Conference on Solid State Devices and Materials. The Japan Society of Applied Physics, 1990. http://dx.doi.org/10.7567/ssdm.1990.s-f-4.

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Kikuchi, Jun, Masao Iga, Shuzo Fujimura e Hiroshi Yano. "Native oxide removal on Si surface by NF 3 -added hydrogen plasma downstream treatment". In Microelectronic Processing '93, a cura di James A. Bondur, Kiefer Elliott, John R. Hauser, Dim-Lee Kwong e Asit K. Ray. SPIE, 1994. http://dx.doi.org/10.1117/12.167335.

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Atalla, Rajai H. "Studies of Polymorphy in Native Cellulose". In Papermaking Raw Materials, a cura di V. Punton. Fundamental Research Committee (FRC), Manchester, 1985. http://dx.doi.org/10.15376/frc.1985.1.59.

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Our studies of cellulose structure based on X-ray diffractometry, Raman spectroscopy, and Solid State ¹³C-NMR have led us to a model which addresses questions of structure at two levels. The first is that of the organization of individual chains. Two stable ordered states of cellulose chains are postulated, together with a disordered state in which there is less coherence between the orientations of adjacent anhydroglucose rings. The ordered states are identified as kᵢ and kᵢᵢ based on their predominance in celluloses I and II, respectively; both conformations are based on the dimeric anhydrocellobiose as the basic repeat until in the ordered chain. The disordered state is identified as kₒ. The second level of organization is that of aggregation of chains into three-dimensionally ordered crystalline domains. At this level our model recognizes two crystalline forms within the native state. These are identified as Iα and Iß, the first found to be dominant in bacterial and algal celluloses, the second dominant in celluloses from higher plants. These two forms are found to contain chains possessing the same molecular conformation ᵏI, but the patterns of hydrogen bonding are found to be different. Cellulose II, which is derived from the native state by mercerization or regeneration at low temperatures, is found to consist predominantly of chains in the ᵏII conformation in yet a third distinct crystalline lattice.

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Findlay, J., C. Olivares, R. Kelly e A. Ismail. "An Integrated Approach to Reducing Risk and Uncertainty in the Early Stages of Native Hydrogen Exploration". In The Fourth EAGE Global Energy Transition Conference and Exhibition. European Association of Geoscientists & Engineers, 2023. http://dx.doi.org/10.3997/2214-4609.202321055.

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MousaviMirkalaei, Seyed Mousa, e Faraj Zarei. "Numerical Simulation for Hydrogen Storage and Bio-Methanation". In SPE EuropEC - Europe Energy Conference featured at the 84th EAGE Annual Conference & Exhibition. SPE, 2023. http://dx.doi.org/10.2118/214395-ms.

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Abstract The potential applications of hydrogen as an energy vector as a part of the solution to decarbonize emissions from use of natural gas and transportation is the subject of much research. Hydrogen storage in the geological subsurface helps to mitigate the effects of fluctuating energy production from renewable energy sources. Nevertheless, there is little comprehensive work on full scale simulation of all the processes associated with the injection, storage and re-producing of hydrogen. Physical phenomena involved in this process include mixing of hydrogen with native components in the reservoir and potentially cushion gas, ga, relative permeability hysteresis, solubility of various gases into the aqueous phase; effect of hydrogen impurity (e.g., CO2, H2S, CH4) and bio-methanation in the presence bacteria. Numerical simulation can be used for dynamic numerical modelling of the storage when all these complex processes are in action. Solubility of hydrogen can be modelled using a solubility table, Henry's correlation, or K-values table. The effect of other gases on the geochemistry of the rock and fluid can be studied in detail using chemical and geochemical reaction concepts. The activity of bacteria in an underground hydrogen storage field may result in synthetic methane production. Such reactions can be modelled based on bacterial activity levels using Arrhenius type reactions. The level of biomass activity depends on salinity, temperature and bacterial types and availability of nutrients. A sub-sector from a North Sea reservoir is used to simulate these processes described and predictions of individual injection/production at various cycles are created. Issues regarding improved monitoring and design of laboratory experiments for future field operations are highlighted. This study shows how simulation can be instrumental in understanding and designing underground hydrogen storage projects, providing predictions of storage volumes, produced gas quality and quantity under various scenarios. The paper also describes the reaction parameters, upscaling, and tuning techniques required for simulation at full field scale.

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Lemaire, Paul J., e Turan Erdogan. "Hydrogen-enhanced UV photosensitivity of optical fibers: Mechanisms and reliability". In Photosensitivity and Quadratic Nonlinearity in Glass Waveguides. Washington, D.C.: Optica Publishing Group, 1995. http://dx.doi.org/10.1364/pqn.1995.sua.4.

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The use of optical fiber gratings1 has rapidly increased in recent years, due to the invention of the side-writing technique,2 and to the availability of fibers with enhanced photosensitivity. Enhanced photosensitivity has been achieved in various ways, most of which serve to increase the concentration of “native” defects in the fibers.3,4,5,6 More recently the UV photosensitivity of optical fibers has been greatly enhanced by “loading” the fibers with molecular H2 or D2 at high pressure.7 Subsequent exposure of the sensitized fiber to intense UV light at wavelengths less than about 248nm causes the physically dissolved H2 to react with cation dopants resulting in the formation of defects which cause large increases in the refractive index of the glass. This high pressure H2 sensitization technique has been used to great advantage in the UV writing of gratings in optical fibers, and has also been used to sensitize planar waveguides for the UV patterning of waveguide devices,8 and in bulk glasses for demonstration of holographic data storage.9 The UV induced index changes can readily exceed the initial core-to- cladding index difference in GeO2 doped fibers, permitting the UV writing of strong gratings in virtually any GeO2 doped optical fiber. The enhanced photosensitivity is sufficient to allow strong gratings to be written in several minutes using pulsed laser systems (~10-30Hz) at typical irradiances of several 100's mJ/cm2. For instance, in standard single mode fiber (3.5% GeO2) index changes of Δn=5x10-3 can be easily achieved and Δn's of 0.011 have been attained with longer exposures. Recent results have shown that H2 sensitization can also be used to advantage in P2O5 doped waveguides and fibers, either by using 193nm excimer irradiation10 or by using simultaneous heating and UV exposure at 248nm.11 One advantage of using H2 sensitization is that any existing fiber (that is either Ge or P doped) can be sensitized after it has been drawn and coated. Hydrogen molecules readily diffuse through polymer coatings and silica claddings at low temperatures, allowing the loading to be done at temperatures as low as 22-75°C, without degradation of polymer coatings. Figure 1 shows the transmission spectrum for a strong grating written in a standard (3.5% GeO2) single mode fiber that was H2 sensitized with 3.3% H2.

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Bianchini, C., R. Da Soghe, A. Andreini, V. Anisimov, A. Bulli, F. Dacca’ e S. Rizzo. "CFD Investigation of a Lean Premixed Burner Redesign for High Hydrogen Content Syngas Operation". In ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gt2015-42479.

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The continuous challenge to develop more efficient and cleaner combustion systems for energy production, promotes the exploitation of traditional fossil fuels in alternative energy cycles capable of abating pollutant emissions. Integrated coal gasification combined cycle (IGCC) technology for instance permits to convert standard coal and other carbon based fuels into hydrogen-rich syngas. These gases are generally used to fuel standard gas turbine engines typically designed for natural gas combustion. Due to the increased propensity to flashback with high hydrogen content, lean premixed burners usually need a specific redesign to ensure adequate flow velocity at the burner exit section so as to extend lean blow out limits. However design practices for flashback prevention are far from being established especially for these unconventional fuels and it is therefore of interest to rely on CFD analysis to establish flame stabilization process and to predict incipient flashback. The purpose of this work is to assess the accuracy and reliability of a CFD methodology to describe the flame anchoring process and exhaust pollutant emissions in a high hydrogen syngas version of a standard swirled lean premixed burner which has been tested in a tubular test rig. Considered numerical setup is based on the use of the Flamelet-Generated Manifolds (FGM) method which is a good choice to combine computational efficiency and detailed chemistry modelling. This work aims at providing a first assessment of the FGM model as implemented in Fluent v15 in the framework of RANS turbulence approach. Four different operating conditions at increasing pressure levels are tested and a detailed sensitivity analysis of the combustion model is provided exploring flamelet generation parameters, turbulence-chemistry interaction closures and methods to assign progress variable variance. A specifically developed detailed chemical mechanism for H2 was implemented and used to verify NOx emission predicting capabilities of three alternative methods: lookup table generated integrating with presumed PDF, automatic reactor network model based on CFD aero-thermal solution and Fluent native NOx model. Obtained results are validated against available experimental data.

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Rapporti di organizzazioni sul tema "Native hydrogen"

Aliyu, Abdul'Aziz. Gold, Geologic, White, Native, Hidden, Natural Hydrogen: Does Earth hold extensive stores of untapped, carbon-free fuel? IEAGHG, giugno 2024. http://dx.doi.org/10.62849/2024-ip05.

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Fernández Gómez, Jorge, e Jaime Menéndez Sánchez. Development of the hydrogen system in the Basque Country in the medium term. A cura di Patricia Canto. Universidad de Deusto, 2023. http://dx.doi.org/10.18543/ukhn2572.

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This report analyzes the possible evolution of the hydrogen transport infrastructure system in the Basque Country in the medium term. The objective of the work is threefold: (1) to characterize medium-term infrastructure development scenarios (over a 10-15 year horizon); (2) to identify key factors that influence the development of the Basque hydrogen system and analyze their potential impact on the determination of the medium-term scenario; (3) to draw conclusions of a strategic nature for the Basque Country. The hydrogen production-transport system scenarios analyzed range from a totally decentralized scenario (with production infrastructures on site, at consumption facilities or in industrial hubs) to a totally centralized system designed on the basis of the current gas network. The main conclusion of the report is that the optimal strategy in the short term from the point of view of the Basque Country involves supporting a rapid deployment of hydrogen in industrial hubs (Port of Bilbao area), while a wait-and-see position should be maintained to see how the sector develops in the coming years to advance in the configuration of infrastructures in the longer term.

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Liseroudi, M. H., O. H. Ardakani, P. K. Pedersen, R. A. Stern, J M Wood e H. Sanei. Diagenetic and geochemical controls on H2S distribution in the Montney Formation, Peace River region, western Canada. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329785.

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The Lower Triassic Montney Formation is a major siltstone dominated unconventional tight gas play in the Western Canadian Sedimentary Basin (WCSB). In the Peace River region, the Montney Formation contains a regionally variable amount of hydrogen sulfide (H2S) in gas-producing wells with western Alberta's wells having the highest concentrations. Previous studies on the source and distribution of H2S in the Montney Formation mainly focused on variations of H2S concentration and its relationship with other hydrocarbon and non-hydrocarbon gases, sulfur isotope composition of H2S, as well as organo-sulfur compounds in the Montney Formation natural gas. None of those studies, however, focused on the role of diagenetic and geochemical processes in the formation of dissolved sulfate, one of the two major ingredients of H2S formation mechanisms, and pyrite within the Montney Formation. According to the results of this study, the Montney Formation consists of two different early and late generations of sulfate minerals (anhydrite and barite), mainly formed by the Montney Formation pore water and incursion of structurally-controlled Devonian-sourced hydrothermal sulfate-rich fluids. In addition, pyrite the dominate sulfide mineral, occurred in two distinct forms as framboidal and crystalline that formed during early to late stages of diagenesis in western Alberta (WAB) and northeast British Columbia (NEBC). The concurrence of the late-stage anhydrite and barite and various types of diagenetic pyrite with high H2S concentrations, particularly in WAB, their abundance, and spatial distribution, imply a correlation between the presence of these sulfate and sulfide species and the diagenetic evolution of sulfur in the Montney Formation. The sulfur isotope composition of anhydrite/barite, H2S, and pyrite demonstrates both microbial and thermochemical sulfate reduction (MSR and TSR) controlled the diagenetic sulfur cycle of the Montney Formation. The relationship between the delta-34S values of the present-day produced gas H2S and other sulfur-bearing species from the Montney and other neighboring formations verifies a dual native and migrated TSR-derived origin for the H2S gas with substantial contributions of in situ H2S in the Montney reservoir.

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Birk, Steffen, Christian Griebler, Johannes C. Haas, Alice Retter, Ainur Kokimova, Constanze Englisch, Santiago Gaviria, Johannes Grath, Heike Brielmann e Christine Stumpp. Impact of extreme hydrological events on the quantity and quality of groundwater in alpine regions – multiple-index application for an integrative hydrogeo-ecological assessment. Verlag der Österreichischen Akademie der Wissenschaften, settembre 2023. http://dx.doi.org/10.1553/ess-integrative-groundwater-assessment.

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Freshwater ecosystems in mountain areas are considered important water resources and biodiversity hotspots that are highly sensitive to changes in climate. The Alpine region is known to be particularly affected by climate change, including changes in hydrological extremes such as droughts and floods, which are expected to become more frequent and intense. Despite the importance of groundwater as a primary water resource, climate change impacts on groundwater quality, including those resulting from hydrological extremes, have been rarely addressed to date. Moreover, groundwater monitoring is currently focused on physical-chemical indicators, whereas groundwater ecological features such as biodiversity and ecosystem functioning are hardly considered. Against this background, this project addressed the following overarching research question: How do groundwater systems in an alpine and prealpine environment respond to extreme hydrological events in terms of water quantity and chemical quality as well as ecological status? To address this question, the valley of the river Mur from its alpine source area at 2000 m a.s.l. to the Austrian–Slovenian border at 200 m a.s.l. was considered. Thus, the investigation area included alpine and prealpine areas, different type of hydrogeological settings and different human impacts. Existing long-term data was complemented by high-resolution monitoring over time and sampling campaigns addressing wastewater-borne micro-pollutants, microbiological parameters, and groundwater fauna. Our results demonstrate a deterioration of water quality from the alpine source area towards the foreland, corresponding to the more intense agricultural and urban land use in the foreland. The vulnerability of groundwater systems to hydrological extremes is closely related to linkages between water quantity and water quality, which are found to be determined by the groundwater recharge mechanisms and their spatiotemporal dynamics. To achieve a more holistic assessment of groundwater systems, we recommend that their ecosystem nature is taken into account by microbiological indicators that complement existing hydrological and hydrochemical indices. The B-A-(E) index is proposed for this purpose but needs further development by transciplinary research involving local experts and stakeholders to define appropriate reference conditions that enable classifications into meaningful water-quality categories.

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Kingston, A. W., O. H. Ardakani, G. Scheffer, M. Nightingale, C. Hubert e B. Meyer. The subsurface sulfur system following hydraulic stimulation of unconventional hydrocarbon reservoirs: assessing anthropogenic influences on microbial sulfate reduction in the deep subsurface, Alberta. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/330712.

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Hydraulic fracturing is a reservoir stimulation technique that involves the injection of high-pressure fluids to enhance recovery from unconventional hydrocarbon reservoirs. Often this involves the injection of surface waters (along with additives such as biocides) into formational fluids significantly different isotopic and geochemical compositions facilitating geochemical fingerprinting of these fluid sources. In some instances, the produced fluids experience an increase in hydrogen sulfide (H2S) concentration over the course of production resulting in an increased risk to health and safety, the environment, and infrastructure due to the toxic and corrosive nature of H2S. However, questions remain as to the origin and processes leading to H2S formation following hydraulic fracturing. In this study, we analyzed a series of produced waters following hydraulic fracturing of a horizontal well completed in the Montney Formation, Western Canada to evaluate variations in geochemical and microbiological composition over time and characterize potential sulfur species involved in the production of H2S. Initially, sulfur isotope ratios (d34S, VCDT) of dissolved sulfate in produced water had a baseline value of 27per mil similar to the d34S value of 25per mil for solid anhydrite derived from core material. Subsequently, d34S values of sulfate in produced fluids sequentially increased to 35per mil coincident with the appearance of sulfides in produced waters with a d34SH2S value of 18per mil. Oxygen isotope values of dissolved sulfate exhibited a synchronous increase from 13.2per mil to 15.8per mil VSMOW suggesting sulfate reduction commenced in the subsurface following hydraulic fracturing. Formation temperatures are &lt;100°C precluding thermochemical sulfate reduction as a potential mechanism for H2S production. We suggest that microbial reduction of anhydrite-derived sulfate within the formation is likely responsible for the increase in H2S within produced waters despite the use of biocides within the hydraulic fracturing fluids. Initial assessments of microbial communities indicate a shift in community diversity over time and interactions between in situ communities and those introduced during the hydraulic fracturing process. This study indicates that biocides may not be fully effective in inhibiting microbial sulfate reduction and highlights the role anthropogenic influences such as hydraulic fracturing can have on the generation of H2S in the subsurface.

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Guidati, Gianfranco, e Domenico Giardini. Joint synthesis “Geothermal Energy” of the NRP “Energy”. Swiss National Science Foundation (SNSF), febbraio 2020. http://dx.doi.org/10.46446/publication_nrp70_nrp71.2020.4.en.

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Near-to-surface geothermal energy with heat pumps is state of the art and is already widespread in Switzerland. In the future energy system, medium-deep to deep geothermal energy (1 to 6 kilometres) will, in addition, play an important role. To the forefront is the supply of heat for buildings and industrial processes. This form of geothermal energy utilisation requires a highly permeable underground area that allows a fluid – usually water – to absorb the naturally existing rock heat and then transport it to the surface. Sedimentary rocks are usually permeable by nature, whereas for granites and gneisses permeability must be artificially induced by injecting water. The heat gained in this way increases in line with the drilling depth: at a depth of 1 kilometre, the underground temperature is approximately 40°C, while at a depth of 3 kilometres it is around 100°C. To drive a steam turbine for the production of electricity, temperatures of over 100°C are required. As this requires greater depths of 3 to 6 kilometres, the risk of seismicity induced by the drilling also increases. Underground zones are also suitable for storing heat and gases, such as hydrogen or methane, and for the definitive storage of CO2. For this purpose, such zones need to fulfil similar requirements to those applicable to heat generation. In addition, however, a dense top layer is required above the reservoir so that the gas cannot escape. The joint project “Hydropower and geo-energy” of the NRP “Energy” focused on the question of where suitable ground layers can be found in Switzerland that optimally meet the requirements for the various uses. A second research priority concerned measures to reduce seismicity induced by deep drilling and the resulting damage to buildings. Models and simulations were also developed which contribute to a better understanding of the underground processes involved in the development and use of geothermal resources. In summary, the research results show that there are good conditions in Switzerland for the use of medium-deep geothermal energy (1 to 3 kilometres) – both for the building stock and for industrial processes. There are also grounds for optimism concerning the seasonal storage of heat and gases. In contrast, the potential for the definitive storage of CO2 in relevant quantities is rather limited. With respect to electricity production using deep geothermal energy (> 3 kilometres), the extent to which there is potential to exploit the underground economically is still not absolutely certain. In this regard, industrially operated demonstration plants are urgently needed in order to boost acceptance among the population and investors.

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NREL Melds Nature with Nanotech for Solar-Powered Hydrogen Production (Fact Sheet). Office of Scientific and Technical Information (OSTI), settembre 2011. http://dx.doi.org/10.2172/1026573.

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